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X-ray topographic studies in the peoples Republic of China
Pmg. C~stai Gmwth and Charact. 1986, Vol. 13, pp. 53-75 Printed in Great Britain. All rights reserved
X-BAY
Copyright 0
TOPOGRAPHIC STUDIES REPUBLIC OF CHINA
IN
THE
lS5
014s353sE5 J0.w + .50 Pergamon Journals Ltd
PEOPLES
S. S. Hsu and B. K. Tanner* Shanghai
Institute of Metallurgy, Academia Sinica, China and *Department Physics, University of Durham, UK
(Received 30th September
of
1988)
ABSTRACT
topographic studies of crystal perfection over the past two decades in the Peoples’ Those papers published in Chinese Journals and in the Chinese Republic of China are outlined. language are reviewed and a summary of instrumentation and research groups presently active is presented.
X-ray
I.
INTRODUCTION
It is well known that X-ray diffraction topography is a powerful tool for the study of crystal perfection and related problems. A great number of research results have been comxmnicated . . . . ._. through numerous screntitlc papers and books published in Europe, the United States, Japan and other countries during the last thirty years. However due to historical reasons, only a limited exchange of information in the field of science and technology existed between China and the western countries up to about ten years ago. Thus very few westerners knew of devNotwithstanding this situation, scientific literature and elopments in this subject in China. other reference material was still available to Chinese scholars in those years. The basic principles and techniques of X-ray topography were introduced into China at the beginning of After 1978, when China instigated the sixties (1,2) and research work immediately followed. have been encouraged to communicate their an open policy to the outside world, scientists to their fellow scientific workers in foreign countries. Some research results and views have participated in international conferences and papers are now published regularly in EuroExtensive international exchange programmes have been arranged pean and American journals. are still published for visiting stholars. However, the major part of their research results in Chinese journals, are mostly written in the Chinese language and are not readily accessible in the west. During an extihange visit to China in 1984 it became clear to one of us (BKT) that a review article concerning Chinese work on the subject of X-ray topography in the past two or three decades, and the present status of the field in China would be of great interest. In response to this proposal, the other author (SSX) was asked by his Chinese colleagues to collaborate in writing this article. The literature review section of this paper describes only the major research achievements Papers presented at international conferences in China which have been published in Chinese. or published in other countries are not included. II. 1.
Theoretical crystals.
Using Green’s
and experimental
function
methods,
REVIEW
OF PUBLISHEDPAPERS
research
the equations
work on the dynamical of X-ray
63
diffraction
diffraction for
perfect
of
X-rays
in
crystals
in
S.S.Hsu
64
and B. K.Tanner
both Laue and Bragg cases were solved by Sun (3,4) of Beijing for transmitted and reflected X-ray wavefields were derived. previous work utilising Riemann functions or Fourier integrals well.
(Peking) University. These results were and were found to
Expressions compared with agree very
A perturbative solution of Takagi’s equations for slightly deformed crystals was carried out by Lin (8) of the Aushan Iron and Steel Engineering Institute. In this paper, deformations with a uniform gradient were considered as a perturbation. An integral equation for the diffraction amplitude was obtained with the help of the Riemann function method. Another new way of solving Takagi’s equations of the dynamical theory of X-ray diffraction using the characteristic curve method was proposed by Sun and Liang (9). Expressions for both strict and approximate solutions have been given and the meaning of the Borrmann triangle can also be explained by this solution. The approximate first order solution provides simple and explicit expressions and coincides with the classical theory and fundamental experiments (10). Sun (11) examined critically the basic postulates of Takagi’s theory. He argued that since the magnitude of X-ray wavelengths is of the same order as that of interatomic distances,the assumption of crystals being continuous media is inaccurate. Sun therefore derived a new set of equations for X-ray diffraction in perfect crystals OK crystals with slight deformations using quantum mechanical collision theory and the perturbative approximation of electrons in solid state physics. The fading of Pendell:sung fringes in diamond crystals was studied by Jiang (12) by means of X-ray diffraction section topography at Nanjing University. The fading periods of dynamical interference fringes were observed in crystal plates and wedge-shaped crystals, as well as in a crystal containing a stacking fault. This phenomenon was adequately interpreted in terms of Quantitative comparison of experiment with theory was made dynamical diffraction theory. and the agreement was found to be quite good. A series of X-ray section topographs was taken for a group of dislocations near the edge of an An interesting series of otherwise perfect silicon wafer (Fig. 1) by Hon, Yang and Xu (13). “sine-curve” type intermediate images was obtained for the first time with AgK,, and MoKol The dislocation was put at different positions in the Borrmanntriangle. radiations (Fig. 2,3). Due to the strong Borrmann effect topographs with CuK,l radiation showed a sharp dynamical However at the tail of the dynamical image corresponding to the dislocation image. near like image the straight line image changed into a “saw-tooth” the exit surface of the wafer, diffraction theory. All these phenomena have been explained by dynamical X-ray (Fig. 4). Computer simulation of these images is presently being undertaken
Fig. 1 Configuration the specimen d,,
d2 on
(171) plane,
of
dislocations
along
[Oil]
in direction
Fig. 2 Section topographs of Si wafer, AgK,, (1Tl) reflection, Nt = 0.59 part of Borrmnn triangle (a) dl at middle
(b) d2 at middle part of Borrmann triangle
X-ray topographic
(a) Fi
c&j
3
Section reflection
(a) (b)
studies in China
65
(b) topographs
of a Si wafer, MoKa,
d, at middle part of Borrmann triangle d2 at middle part of Borrmann triangle
Fig. 4 Section topograph of a Si wafer showing strong Borrmann effect, CuKcc 1' Pt = 10.26 (lrl) reflection,
Section topographs of the growth bands in silicon crystal wafers were taken under medium absorption conditions by Mai et al (14) of the Institute of Physics, Academia Sinica. Borrmann-Lehmann interference fringes have been identified. Work continues on a full theoretical explanation and computer simulations. X-ray section topographs showing the Kc- and Kg images of a naturp quartz crystal containing a Brazil twin boundary were taken by Yang, Jiang et al (15) with g = [1231] and pt = 1.15, as shown in Fig. 5 and Fig. 6. Since the absolute value of the crystal structure factor for both sides of the Brazil twin boundary in the same, the dynamical diffraction image of this boundary should have the same characteristics as that of a stacking fault (16-18). The 'hourglass" patterns characteristic of stacking faults were indeed found. The symmetrical characteristics of the first fringe in Ko-image is shown in Fig. 6. From the sign of this first fringe, the nature of the a-boundary can be determined. 2.
Applied Research into Crystal Defects
Dislocations in a germanium crystal wafer were studied using Borrmann X-ray topography at the Shanghai Institute of Metallurgy, Academia Sinica by Xu, Yang and Tan (2) (Fig. 7), which is believed to be the first work on X-ray diffraction topography performed in China. The configuration of the grown-in dislocations in the crystal was analysed by a space projection method. Most of the dislocations were found to lie only on (lh) and (rll) planes and were considered to be connected with the growth conditions (swirls) in Czochralski grown silicon crystalswere observed directly without Micro-defects decoration using X-ray transmission projection topography and section topography by Mai et al. (19) Two kinds of "as-grown" microdefects were observed (Fig. 8), their configuration and behaviour being similar to the A, B microdefects reported by previous investigators. Two other typesof microdefects with special configurations were also discovered. An optical processing method for the topographs was also developed which significantly improved the contrast (20). Xu and his co-workers (21,22) investigated the defects in the twin boundary region of a silicon crystal. Imperfect twin interfaces with dislocations and/or stacking faults were observed in addition to the perfect twin interfaces (Fig. 9). A step structure of twin interfaces has been described. A twin-fault model has been proposed to explain the experimental phenomena observed.
66
S. S. Hsu and 6. K.Tanner
Fig. 5 Section topograph of the Brazil twin boundary in a-quartz crystal + g = [12311, Pt = 1.15 Kg-image
Fig. 6 Section topograph of the Brazil twin boundary in u-quartz crystal + g = [1231], Pt = 1.15 Ko-image
Fig. 7 Borrnann topograph of a germanium crystal CuKu,, Pt = 10.54 (a) Ko-image (b) Kg-image.
220
reflection, wavefield vector [llll
X-ray topographic
studies in China
67
(b) Fig. (b)
8 Microdefects in a Si longitudinal section
crystal
wafer
MOKCY 220
reflection
(a)
cross
section
Xu et al also studied the dislocations and stacking faults in silicon web dendrites, grown in their own institute, by means of X-ray projection topography. In addition to the usual edge-, screwand 60°-type total dislocations and edge-type Shockley partial dislocations, 30”-and 60°-type Shockley partial dislocations with Burgers vector 1 <112> have been observed (Fig. 10). Several dislocation reactions in a single slip plane have K been found. The configuration and contrast of stacking faults in as-grown webs changed upon high temperature annealing. This can be explained by the motion of extended dislocation pairs and the overlapping of stacking faults with each other in different layers. Hydrogen induced defects in floating zone grown (FZ) silicon single crystals are of Several research groups undertook X-ray topographic interest to Chinese scientists. gations of this material,supporting other characterisation techniques.
special investi-
Cui, Mai and their colleagues (23-25) have played an important role in the study of hydrogen They identified the existence of Si-H bonds in silicon in the solid induced defects in Si. state. When the annealing temperature reached a certain value, breakdown of these bonds In connection with the resulted, which was confirmed by infrared absorption spectroscopy. type defect was formed (Fig. 11,12). breakdown of the Si-H bonds, a “snow-flake” The flakes are seen to be along the directions and are composed of helical or prismatic loops. Jiang and his co-workers (26) at the Beijing investigated the formation and configuration They confirmed the existence of three kinds absorption peaks with wave-lengths of 4.55, defects originated from hydrogen precipitation precipitation was found to be 2.4 eV.
University of Iron and Steel Technology also of hydrogen induced defects in FZ silicon crystals. of Si-H bond corresponding to the three infrared 4.75 and 5.13 urn respectively. The heat treatment in the crystal. The activation energy for the
Academia Sinica studied defects in Yang and Zhu (27) at the Shanghai Institute of Metallurgy, FZ silicon crystals grown both in pure hydrogen and in an atmosphere containing hydrogen and The effects of annealing+as shown by chemical etching and X-ray topography, indicated argon. that the highest defect density in as-grown crystals had occurred in an atmosphere containing 10X hydrogen. synthetic quartz (28,29) LiNb03 The growth defects in natural quartz (51), A!&P04 (34), Beryl (35), KAP (36,37) Hg,_xC+Te, Pbl-$nxTe (38.39) and been studied in various institutions in China with interesting results.
(30,31) YAG (32,33), other crystals have
68
S. S. Hsu and B. K.Tanner
Fig. 9 Projection topograph of a twin boundary Fig. 10 Projection topograph of Si web dendrite in as grown state in a Si crystal wafer ; = [333]
MoKa, A edge-type total dislocation , $=l[liOl II B 600_ (1 (1 C I! 11 II II 1 g:$;y,' 1 edge-type Shockley partial di%locatjon.
2 edge- "
I(
,I
b=1[2111 B dislocation, Lr [i2ii g
dislocatjon, k;r1121
Fig. 11 Hydrogen induced defects in a Si crystal annealed lhr at 1000°C AgKa, , 220 reflection
Fig. 12 Relationship between the formation of hydrogen-induced defects and the breakdown of Si-H bonds
X-ray topographic
studies in China
69
The contrast
of defects in X-ray topographs of a-LiI03 under a DC field applied along the caxis has been investigated. The diffraction contrast changed remarkably under the action of applied electrostatic fields. The effect was reversible and the original contrast was restored after the removal of the field. This phenomenon was explained in terms of a decoration of space charges accumulated on the crystal defects whereby the locallattice distortion around the defects was enhanced. (40) X-ray topography was also used to study the fracture process and morphology in three point bending tests of MO single crystals. Variations in a plastic zone in front of the pre-cracks in the fracture process were shown. (41) 3.
Doubleand
Multiple-Crystal Diffractometry
A three dimensional DuMond diagram has been constructed from the consideration of dynamical diffraction theory by Xu and Li. (42) The dispersion of wavelengths, vertical,and horizontal divergences of X-rays have been included to construct a complete diagram as shown in Fig. 13. Such a diagram can be used to analyse the successive diffraction of X-rays by multiple crystals. Xu, Chen and Li (43) used this three dimensional DuMond diagram for the analysis of single-and double- crystal spectrometry and for high precision measurements of the CuKa, line profile. The changes of maximum reflection coefficient,half maxirmm line breadth, integrated reflection
e
e
(a)
(b)
Fig. 13 Three dimensional DuMond diagrams (a) X > 0 (b) X < 0 (X is the angle between diffraction plane and the crystal surface)
the
power and change of lattice plane spacing of some planes in cc-LiIO3 single crystals, under the action of an electrostatic field along the z-axis and x-axis, ha+e been investigated by Liang and Yi (44,45) using double crystal diffractometry with a (n,-n) setting. A possible explanation is suggested in terms of displacement and rotation of the 103-group along and around the z-axis, and the existence of a gradient of lattice constant c under the action of the field. Lattice parameter variationsof YAG crystals doped with Nd have been measured by Gao et al (46) at Changchun Institute of Physics, Academia Sinica using the double-crystal method. It is concluded from the experimental data that the variation of lattice paramter is due to the non-uniform distribution of Nd ions in the crystal. Effects of heat treatment on an ion implanted yttrium irongarnet (YIG) epitaxial layer on a gadolinium gallium garnet (GGG) substrate were studied by means of double crystal diffractometry with an asymmetric setting by Tan (47). Experimental results indicated that ion implantation had increased greatly the lattice mismatch between the epitaxial layer and the substrate, the relation between the lattice mismatch and heat treating temperature being found to be a very complex one.
S.S. Hsu and 6. K.Tanner
70
Double- and trie-crystal diffractometry has been used to investigate the lapping and polishing damage in single crystal wafers of Si, GaAs and GGG. This technique was also applied to the simultaneous determination of flexure, lattice mismatch and composition of Ga AllxAs epitaxial layers on GaAs substrates by Xu and his co-workers (48,49). Very small-x flexures of crystal wafers were measured successfully by Chen et al (50) by means of double crystal diffractometry in a special asymmetrical setting. III.
PRESENT STATUS OF ACTIVITY
In order to give an indication of the level of activity in China at present, in this section we have gathered together data concerning research groups, personnel and facilities. As is evident, there are a large number of scientists active and the facilities at several institutions are of world class. It is clear that the Chinese community will make a major contribution to materials characterization over the next decade, particularly in response to the rapid improvements presently being made in crystal quality. 1.
Research Groups and Facilities
A.
Institute of Physics, Academia Sinica, Beijing
B.
Personnel:
b)
Facilities: Rigaku RU-1000 (6OKW rotating target X-ray generator) with large scale Rigaku Lang camera and TV camera system. Rigaku D.MAX-RA (12 KW generator) with Marconi Lang camera.
Peking University, Beijing a)
C.
D.
E.
F.
G.
Personnel:
Sun Zhang-de*, Liang Jin-guo
University of Iron and Steel Technology, Beijing a)
Personnel:
b)
Facilities:
Jiang Bai-lin*, Sheng Shi-xiong, Xias Zhu-gang Rcgaku D/MAX-RA with A-3 Lang camera, Philip APD-10 Diffractometer set.
Shanghai Institute of Metallurgy, Academia Sinica a)
Personnel: Xu Shun-shing*, Jiang Xiao-long, Li Run-shen, Xu Jing-yang, Yang Chuan-zhing, et al
b)
Fac&ities: Rigaku D/MAX-RA with A-3 Lang camera. Domestic X-ray generators with remote control Lang camera and SIM-I, SIM-2 high precision double-crystal SIM diffractometer, SIM multiple-crystal diffraction set.
Shanghai Institute of Ceramics, Academia Sinica Guo Chang-lin*, Huang Yue-hong
a)
Personnel:
b)
Facilities: Rigaku RU-500 with TV camera system, Rigaku D/MAX-RA with Lang camera for large specimens LGL-8, Rigaku scanning type double-crystal topographic goniometer CN 1518 Bl.
Fujian Institute of Research on the Structure of Matter, Fuzhou, Fujian Zhao Qin-lan*, Chen Jin-chang, Huang Yi-sen.
a)
Personnel:
b)
Facilities: Rigaku generator with Lang camera. Domestic generator with SIM-II high precision double-crystal diffractometer.
Changchun Institute of Physics, Changchun, Jilin a)
*
Mai Zhen-hong*, Cui Shu-fan, Ge Pei-wen, Wu Lan-shing, Zhao Ya-fing, et al
a)
Personnel: Gao Da-chao*, Liu Wei-na*
Group Leader **Shanghai Institute of Metallurgy, Academia Sinica.
X-ray topographic b)
H.
I.
studies in China
71
Facilities:
Rigaku D/MAX-RA with Lang camera and scanning type double-crystal topographic goniometer CN 1518 Bl.
Nanjing University, Nanjing, Jiangsu Jiang Shu-sheng*,Zhou Heng-natir Yang Ping.
a)
Personnel:
b)
Facilities: Rigaku 4180 El fine focus X-ray generator with A-3 Lang camera Rigaku D3F generator with domestic Dan Dong W-l Lang camera Rigaku D/MAX-RB with Marconi Lang camera
Other Institutions
a)
Wuhan University, Wuhan, Hubai
b)
Wuhan Institute of Building Materials, Wuhan,Hubai
Cl
Hebai Institute of Technology, Tianjin
d)
Shanghai Institute of Applied Physics, Academia Sinica
e)
Kunming Institute of Physics, Kunming, Yunnan
f)
Emei Institute of Semiconductor Materials (Rigaku RU-1000 with TV camera system and large specimen Lang camera, double crystal topographic goniometer CN 151 Bl)
2.
Synchrotron radiation X-ray sources
Two synchrotron radiation storage rings are under construction in China. be brought into use within two or three years. A.
Both of them will
BEPC at the Institute of High Energy Physics, Academia Sinica, Beijing
This will be a source parasitic on an electron-positkon intersecting storage ring designed for high energy physics experiments. This machine will operate at a maximum energy between 2.2 and 2.8 GeV with beam current up to 150 mA. It will be a ring of total radius 40 m with five synchrotron radiation beam lines feeding a total of seven experimental stations. In addition to EXAFS, small angle scattering, powder diffraction, diffuse scattering, photoelectron spectroscopy and X-ray lithography, one station will be dedicated to X-ray topography. The station will be situated about 40 m from a 1.8T wiggler magnet and transmitted through a 0.5 mm thick Be window, providing radiation of critical wave length 1.32 from a source 15mm x9 mm (lo values). Initially a white radiation camera will be installed and followed subsequently by a double-crystal camera which can lQe used alternatively with the white radiation camera. With an estimated total flux of 6 x 10 photonsisec at E = 1.8GeV, X = 1.5 8 and 1% band width, this will provide a first class facility which will play an important role in the future development of this field in China. B.
c
This is a storage ring designed to provide synchrotron radiation at lower energy levels. It will be operated at 800 MeV, and will be very useful for lithography, small angle scattering, photoelectron spectroscopy and other spectroscopy, photo-chemistry and photobiology research work. However, with the insertion of superconductor wiggler magnets in the future, experimental stations for X-ray topography and EXAFS will be installed.
*
Group Leader ** Shanghai Institute of Metallurgy, Academia Sinica
72
S.S. Hsu and 6. K.Tanner IV.
CONCLUSIONS
Despite limited information exchange prior to 1978, it is evident that a considerable level of activity existed within China during the two previous decades. This has provided a sound base for the current developments. A 10 day lecture course given by one of us (BKT) at the University of Nanjing in the autumn 1984 attracted over 30 scientists from 19 institutions throughout China, and the book "X-ray Diffraction Topography" by the same author has recently been translated into Chinese. X-ray topography and precision diffractometry are seen as major characterization tools in China and we can be confident that the present rate of expansion will continue for some time to come. A new book in Chinese will appear in 1986.(52) V.
ACKNOWLEDGEMENTS
It is with great pleasure that we thank our friends and colleagues Mai Zhen Hong and Jiang ShuSheng for providing much of the background material used in compiling this article. References 1.
Xu Shun-sheng (S.S. Hsu), X-ray Diffraction by Metals (book), Shanghai Publishing House of Science and Technology, (1962).
2.
Xu Shun-sheng (S.S. Hsu), Yang Chuan-zheng and Tan Song-sheng, Direct observation and analysis of dislocations in germanium crystals by means of Borrmann X-ray topography. Presented to the First National Conference on Defects in Crystals and Strength of Metals, Nov. 1964, Nanjing, China.
3.
Sun Zhang-de, Solving the equations of X-ray diffraction by Green function, Acta Phys. Sinica, 32, 982, (1983)
4.
Sun Zhang-de, Solution of the equation of X-ray diffraction by Green function in Bragg case, Acta Phys. Sinica, 21, 1460 (1983).
5.
T. Uragami, J. Phys. Sot. Jpn., 27_, 147 (1969); 28, 1508 (1970);
6.
T. Saks, T. Katagawa and N. Kato, Acta Cryst., e,
7.
Z.G. Pinsker, Dynamical Scattering of X-rays in Crystals, Springer-Verlag, Berlin, P.388, (1978).
8.
Ling Bing-chang, Perturbative solution of Takagi equation in X-ray diffraction dynamics in slightly deformed crystal, Acta Phys. Sinica, 2, 1528, (1981).
9.
Sun Zhang-de and Liang Jing-guo, A new method of solving the Takagi equation of the dynamical theory of X-ray diffraction, Acta Phys. Sinica, 30, 344, (1981).
10.
A.Authier, Modern Diffraction and Imaging Techniques in Materials Science, North Holland, Amsterdam 1978.
11.
Sun Zhang-de, On the quantum mechanical equations of X-ray diffraction and theirsolutions Presented to the Third National Conference on X-ray diffraction, NOV. 1985, Chengdu, China.
12.
Jiang Shu-sheng, Fading phenomenon of PendellBsung fringes in X-ray section topography, Acta Phys. Sinica, 2, 1497, (1983).
13.
Hou Ping, Yang Chuan-zheng and Xu Shun-sheng (S.S. Hsu), The observation and analysis of diffraction images of dislocation by dynamical X-ray topography. Presented to the Third National Conference on Defects in Solids, Sept. 1985, Wuhan, China.
14.
Mai Zhen-hong, to be published.
15.
Yang Ping, Jiang Shu-sheng, Zhou Heng-nan and Feng Duan, The X-ray dynamical diffraction images of a twin boundary in naturally occurring quartz crystal. Presented to the Third National Conference on X-ray Diffraction, Chengdu, China; Chn. Phys. Lett., (1986) No. 1.
31, 1141, (1971)
102, 113, (1972); 2,
192, (1973)
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17.
N.
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S.S. Jiang (Jiang Shu-sheng) and A.R. Lang, Proc. Roy. Sot. Lond., e,
19.
Mai Zhen-hong, Cui Shu-fan, Fu Quan-gui, Liu Ru-gan and Zhang Jin-fu, Observation on "as grown" microdefects in CZ silicon single crystal, Acta Phys. Sinica, 32, 686, (1983).
20.
Zhen Shi-hai and Mai Zhen-hong. The optical processing of X-ray topographs for the direct observation of micro-defects in silicon crystals, Kexue Tongbao, 27, 1231, (1982).
21.
Xu Shun-sheng (S.S. Hsu), Yang Chuan-zheng and Jiang Xiao-long. The structure of and the defects in the twin interface of silicon single crystal, Chn. J. Semiconductor, 3, 270, (1982).
22.
Yang Chuan-zheng, Jiang Xiao-long and Xu Shun-sheng (S.S. Hasu), X-ray topographic study of dislocations and stacking faults in silicon web dendrites, Acta Phys. Sinica, 2, 341, (1980).
23.
Cui Shu-fan, Ge Pei-wen, Zhao ya-qin and Wu Lan-sheng. The presence of Si-H bonds in Si single crystals and its influence, Acta Phys. Sinica, a, 791 (1979).
24.
Cui Shu-fan, Mai Zhen-hong and Qian Lin-zhao (L.C. Tsien). The Si-H bonds and H-induced defects in single crystal of silicon, Scientia Sinica &l (1983), 1033 (in Chinese); g, 213 (in English).
25.
Mai Zhen-hong, Cui Shu-fan, Li Jian and Ln Yan Study of hydrogen induced defects in floating zone silicon grown in hydrogen atmosphere, Acta Phys. Sinica, 22, 921, (1984)
26.
Jiang Bai-lin, Sheng Shi-xiong and Xiao Zhi-gang. Mechanism of the formation of the defects during heat treatment in single silicon crystal grown in floating zone method under pure hydrogen, Acta Phys. Sinica, 9, 1283, (1980).
27.
Yang Chuan-zheng and Zhu Jian-sheng. Investigation of the defects in silicon single crystal grown by floating-zone method in the atmosphere containing hydrogen, Acta Phys. Sinica, 21, 278, (1982).
28.
Zhong Wei-zhuo. The crystallization habit and defects of synthetic quartz, Acta Phys. Sinica, 2, 240, (1979).
29.
Mai Zhen-hong, Ge Pei-wen, Cui Shu-fan and Wu Lan-sheng. The observation of defects in synthetic quartz by X-ray topography, Acta Phys. Sinica, 30, 1106 (1981).
30.
Zhou Heng-nan and Jiang Shu-sheng, X-ray diffraction topographic study of crystal defect in LiNbO 3, Acta Phys. Sinica, 9, 374 (1980).
31.
Guo Chang-ning and Huang Yue-hong, X-ray topographic sutdy of LiNb03: Kexue Tongbao, 25, 206 (1980).
32.
Mai Zhen-hong, Ge Pei-wen, Cui Shu-fan, Xiao Nan and Wu Lan-sheng. The observation on defects in YAG single crystal by X-ray transmission topography, Acta Phys. Sinica, 30, 999 (1981).
33.
Gao Da-chao, Cui Yu-shun, Li Mei et al. The observation of defects in YAG crystals using double crystal topography. Presented to the Third National Conference on Defects in Solids, Sept. 1985, Wuhan, China.
34.
Jiang Bai-lin, Xu Bin, Liu Xi-lin and Han Jian-ru. X-ray diffraction topography study of defects in AlP04 crystals, Acta Phys. Sinica, 36, 1229, (1985).
35.
Jiang Shu-sheng and Li Qi. X-ray topographic study of defects in beryl. Presented to the Third National Conference on X-ray Diffraction. Nov. 1985, Chengdu, China.
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(1968).
Kato, Adv. X-ray Anal., lo, 46 (1967). 249 (1983)
Fe crystal,
74
S. S. Hsu and 6. K.Tanner
36.
Zhao Qin-lan, X-ray topographic study of the imperfections in KAP crystal, Presented to the Third National Conference on Defects in Solids, Sept. 1985, Wuhan, China.
37.
Zhao Qin-lan, The dislocation contrast in X-ray diffraction topographs of absorbing crystal KAP. Presented to the Third National Conference on X-ray Diffraction, Nov. 1985, Chengdu, China.
38.
Yu Fu-ju, X-ray topographic examination of defects in ternary Hg0.8Cdo 2Te and Pb0.8Sno 2Te single crystals, Wuli (Physics, Bimonthly), 2 508 (1980):
39.
Su Yi, The observation of crystal defects in Hg,_,Cd Te using X-ray topography. Presented to the Third National Conference on X-ray Diffraction, Nov. 1985, Chengdu, China.
40.
Gu Yuan-xin, Ge Pei-wan, Zhao Ya-qin, Hu Bo-qing, Wu Lansheng and Fu Quan-gui, X-ray topographical study on defects in a-LiIO3 decorated by space charge due to the applied fields, Acta Phys. Sinica, 2, 711 (1980).
41.
An Zheng-zhi and Ha Kuan-fu, An X-ray diffraction topographic method and its applicatior to fracture problem of metal, Acta Met. Sinica, 18, 286.
42.
Xu Shun-sheng (S.S. Hsu) and Li Run-shen, The three dimensional dynamic DuMond diagram for X-ray diffraction analysis of nearly perfect crystal. Presented to the Third National Conference on X-ray Diffraction, Nov. 1985, Chengdu, China.
43.
Xu Shun-sheng (S.S. Hsu), Chen Jing-yi and Li Run-sheng. Analysis of single- and double-crystal spectrometry using three dimensional DuMond diagrams and the high precision measurement of CuK,l line profile, ibid.
44.
Liang Jing-kui and Yi Sun-sheng, An X-ray double crystal spectrometric investigation of the behaviour of a-LiI03 single crystals under the action of electro-static field, Acta Phys. Sinica, 7, 126 (1978).
45.
Yi Sun-sheng and Liang Jing-kui, Variation of lattice constants in the a-LiI03 single crystal under the action of an electrostatic field, Acta Phys. Sinica, g, 314 (1978)
46.
Gao Da-chao, Li Mei, Lou Tai-ping and Cui Yu-shun, The measurement of lattice parameter variation of YAG crystal using double crystal topography. Presented to the Third National Conference on X-ray Diffraction, Nov. 1985, Chengdu, China.
47.
Tan Ru-huan, The Study of heat treatment of GGG crystal after ion implantation by means of X-ray double crystal diffractometry, ibid.
48.
Xu Shun-sheng (S.S. Hsu), Xu Jing-yang and Tan Ru-huan. Investigation methods of lappir and polishing damages in single crystal wafers by X-ray double and triple-crystal diffractometry, Chn. J. Semiconductor, 2, 95 (1982).
49.
Xu Jing-yang, Tan Ru-huan and Xu Shun-sheng (S.S. Hsu), Simultaneous determination of fletire, lattice mismatch and composition of Gal_xA1,As epitaxial layer on GaAs by mean: Presented to the Second National Conference on X-ray of double-crystal diffractometry. Diffraction, Dec. 1982, Shanghai, China.
50.
Chen Jing-yi, Li Run-shen and Xu Shun-sheng (S.S. Hsu), The measurement ofsvery small flex ure in crystal wafers using double-crystal diffractometry with (n", n ) setting. Presented to the Third National Conference on X-ray Diffraction, Nov. 1985,
51.
Zhou Heng-nan, X-ray topographic study of twin boundaries in natural n-quartz, Acta Mineral, Sinica, 5, 254, (1985).
52.
Xu Shun-sheng and Feng Duan (eds.) Press, Beijing, 1986.
X-ray Diffraction Contrast Topography, Science
X-ray topographic
studies in China
THE AUTHORS
Xu Shun Sheng received his B.S. degree from the National Wuhan University of China in 1943 and his Ph.D. from the University of Notre Dame, U.S.A. in 1953. He is Research Professor of Materials Science and X-ray diffraction at the Shanghai Institute of Metallurgy, Academia Sinica and Chairman of the X-ray diffraction committee of the Chinese Society of Physics. Brian K. Tanner received his B.A. degree from Oxford University in 1968, gaining a D. Phil. from the same university in 1972. He is Reader in Physics at the University of Durham, a Director of Bede Scientific Instruments and a Fellow of the Institute of Physics.
75
X-BAY
Copyright 0
TOPOGRAPHIC STUDIES REPUBLIC OF CHINA
IN
THE
lS5
014s353sE5 J0.w + .50 Pergamon Journals Ltd
PEOPLES
S. S. Hsu and B. K. Tanner* Shanghai
Institute of Metallurgy, Academia Sinica, China and *Department Physics, University of Durham, UK
(Received 30th September
of
1988)
ABSTRACT
topographic studies of crystal perfection over the past two decades in the Peoples’ Those papers published in Chinese Journals and in the Chinese Republic of China are outlined. language are reviewed and a summary of instrumentation and research groups presently active is presented.
X-ray
I.
INTRODUCTION
It is well known that X-ray diffraction topography is a powerful tool for the study of crystal perfection and related problems. A great number of research results have been comxmnicated . . . . ._. through numerous screntitlc papers and books published in Europe, the United States, Japan and other countries during the last thirty years. However due to historical reasons, only a limited exchange of information in the field of science and technology existed between China and the western countries up to about ten years ago. Thus very few westerners knew of devNotwithstanding this situation, scientific literature and elopments in this subject in China. other reference material was still available to Chinese scholars in those years. The basic principles and techniques of X-ray topography were introduced into China at the beginning of After 1978, when China instigated the sixties (1,2) and research work immediately followed. have been encouraged to communicate their an open policy to the outside world, scientists to their fellow scientific workers in foreign countries. Some research results and views have participated in international conferences and papers are now published regularly in EuroExtensive international exchange programmes have been arranged pean and American journals. are still published for visiting stholars. However, the major part of their research results in Chinese journals, are mostly written in the Chinese language and are not readily accessible in the west. During an extihange visit to China in 1984 it became clear to one of us (BKT) that a review article concerning Chinese work on the subject of X-ray topography in the past two or three decades, and the present status of the field in China would be of great interest. In response to this proposal, the other author (SSX) was asked by his Chinese colleagues to collaborate in writing this article. The literature review section of this paper describes only the major research achievements Papers presented at international conferences in China which have been published in Chinese. or published in other countries are not included. II. 1.
Theoretical crystals.
Using Green’s
and experimental
function
methods,
REVIEW
OF PUBLISHEDPAPERS
research
the equations
work on the dynamical of X-ray
63
diffraction
diffraction for
perfect
of
X-rays
in
crystals
in
S.S.Hsu
64
and B. K.Tanner
both Laue and Bragg cases were solved by Sun (3,4) of Beijing for transmitted and reflected X-ray wavefields were derived. previous work utilising Riemann functions or Fourier integrals well.
(Peking) University. These results were and were found to
Expressions compared with agree very
A perturbative solution of Takagi’s equations for slightly deformed crystals was carried out by Lin (8) of the Aushan Iron and Steel Engineering Institute. In this paper, deformations with a uniform gradient were considered as a perturbation. An integral equation for the diffraction amplitude was obtained with the help of the Riemann function method. Another new way of solving Takagi’s equations of the dynamical theory of X-ray diffraction using the characteristic curve method was proposed by Sun and Liang (9). Expressions for both strict and approximate solutions have been given and the meaning of the Borrmann triangle can also be explained by this solution. The approximate first order solution provides simple and explicit expressions and coincides with the classical theory and fundamental experiments (10). Sun (11) examined critically the basic postulates of Takagi’s theory. He argued that since the magnitude of X-ray wavelengths is of the same order as that of interatomic distances,the assumption of crystals being continuous media is inaccurate. Sun therefore derived a new set of equations for X-ray diffraction in perfect crystals OK crystals with slight deformations using quantum mechanical collision theory and the perturbative approximation of electrons in solid state physics. The fading of Pendell:sung fringes in diamond crystals was studied by Jiang (12) by means of X-ray diffraction section topography at Nanjing University. The fading periods of dynamical interference fringes were observed in crystal plates and wedge-shaped crystals, as well as in a crystal containing a stacking fault. This phenomenon was adequately interpreted in terms of Quantitative comparison of experiment with theory was made dynamical diffraction theory. and the agreement was found to be quite good. A series of X-ray section topographs was taken for a group of dislocations near the edge of an An interesting series of otherwise perfect silicon wafer (Fig. 1) by Hon, Yang and Xu (13). “sine-curve” type intermediate images was obtained for the first time with AgK,, and MoKol The dislocation was put at different positions in the Borrmanntriangle. radiations (Fig. 2,3). Due to the strong Borrmann effect topographs with CuK,l radiation showed a sharp dynamical However at the tail of the dynamical image corresponding to the dislocation image. near like image the straight line image changed into a “saw-tooth” the exit surface of the wafer, diffraction theory. All these phenomena have been explained by dynamical X-ray (Fig. 4). Computer simulation of these images is presently being undertaken
Fig. 1 Configuration the specimen d,,
d2 on
(171) plane,
of
dislocations
along
[Oil]
in direction
Fig. 2 Section topographs of Si wafer, AgK,, (1Tl) reflection, Nt = 0.59 part of Borrmnn triangle (a) dl at middle
(b) d2 at middle part of Borrmann triangle
X-ray topographic
(a) Fi
c&j
3
Section reflection
(a) (b)
studies in China
65
(b) topographs
of a Si wafer, MoKa,
d, at middle part of Borrmann triangle d2 at middle part of Borrmann triangle
Fig. 4 Section topograph of a Si wafer showing strong Borrmann effect, CuKcc 1' Pt = 10.26 (lrl) reflection,
Section topographs of the growth bands in silicon crystal wafers were taken under medium absorption conditions by Mai et al (14) of the Institute of Physics, Academia Sinica. Borrmann-Lehmann interference fringes have been identified. Work continues on a full theoretical explanation and computer simulations. X-ray section topographs showing the Kc- and Kg images of a naturp quartz crystal containing a Brazil twin boundary were taken by Yang, Jiang et al (15) with g = [1231] and pt = 1.15, as shown in Fig. 5 and Fig. 6. Since the absolute value of the crystal structure factor for both sides of the Brazil twin boundary in the same, the dynamical diffraction image of this boundary should have the same characteristics as that of a stacking fault (16-18). The 'hourglass" patterns characteristic of stacking faults were indeed found. The symmetrical characteristics of the first fringe in Ko-image is shown in Fig. 6. From the sign of this first fringe, the nature of the a-boundary can be determined. 2.
Applied Research into Crystal Defects
Dislocations in a germanium crystal wafer were studied using Borrmann X-ray topography at the Shanghai Institute of Metallurgy, Academia Sinica by Xu, Yang and Tan (2) (Fig. 7), which is believed to be the first work on X-ray diffraction topography performed in China. The configuration of the grown-in dislocations in the crystal was analysed by a space projection method. Most of the dislocations were found to lie only on (lh) and (rll) planes and were considered to be connected with the growth conditions (swirls) in Czochralski grown silicon crystalswere observed directly without Micro-defects decoration using X-ray transmission projection topography and section topography by Mai et al. (19) Two kinds of "as-grown" microdefects were observed (Fig. 8), their configuration and behaviour being similar to the A, B microdefects reported by previous investigators. Two other typesof microdefects with special configurations were also discovered. An optical processing method for the topographs was also developed which significantly improved the contrast (20). Xu and his co-workers (21,22) investigated the defects in the twin boundary region of a silicon crystal. Imperfect twin interfaces with dislocations and/or stacking faults were observed in addition to the perfect twin interfaces (Fig. 9). A step structure of twin interfaces has been described. A twin-fault model has been proposed to explain the experimental phenomena observed.
66
S. S. Hsu and 6. K.Tanner
Fig. 5 Section topograph of the Brazil twin boundary in a-quartz crystal + g = [12311, Pt = 1.15 Kg-image
Fig. 6 Section topograph of the Brazil twin boundary in u-quartz crystal + g = [1231], Pt = 1.15 Ko-image
Fig. 7 Borrnann topograph of a germanium crystal CuKu,, Pt = 10.54 (a) Ko-image (b) Kg-image.
220
reflection, wavefield vector [llll
X-ray topographic
studies in China
67
(b) Fig. (b)
8 Microdefects in a Si longitudinal section
crystal
wafer
MOKCY 220
reflection
(a)
cross
section
Xu et al also studied the dislocations and stacking faults in silicon web dendrites, grown in their own institute, by means of X-ray projection topography. In addition to the usual edge-, screwand 60°-type total dislocations and edge-type Shockley partial dislocations, 30”-and 60°-type Shockley partial dislocations with Burgers vector 1 <112> have been observed (Fig. 10). Several dislocation reactions in a single slip plane have K been found. The configuration and contrast of stacking faults in as-grown webs changed upon high temperature annealing. This can be explained by the motion of extended dislocation pairs and the overlapping of stacking faults with each other in different layers. Hydrogen induced defects in floating zone grown (FZ) silicon single crystals are of Several research groups undertook X-ray topographic interest to Chinese scientists. gations of this material,supporting other characterisation techniques.
special investi-
Cui, Mai and their colleagues (23-25) have played an important role in the study of hydrogen They identified the existence of Si-H bonds in silicon in the solid induced defects in Si. state. When the annealing temperature reached a certain value, breakdown of these bonds In connection with the resulted, which was confirmed by infrared absorption spectroscopy. type defect was formed (Fig. 11,12). breakdown of the Si-H bonds, a “snow-flake” The flakes are seen to be along the
University of Iron and Steel Technology also of hydrogen induced defects in FZ silicon crystals. of Si-H bond corresponding to the three infrared 4.75 and 5.13 urn respectively. The heat treatment in the crystal. The activation energy for the
Academia Sinica studied defects in Yang and Zhu (27) at the Shanghai Institute of Metallurgy, FZ silicon crystals grown both in pure hydrogen and in an atmosphere containing hydrogen and The effects of annealing+as shown by chemical etching and X-ray topography, indicated argon. that the highest defect density in as-grown crystals had occurred in an atmosphere containing 10X hydrogen. synthetic quartz (28,29) LiNb03 The growth defects in natural quartz (51), A!&P04 (34), Beryl (35), KAP (36,37) Hg,_xC+Te, Pbl-$nxTe (38.39) and been studied in various institutions in China with interesting results.
(30,31) YAG (32,33), other crystals have
68
S. S. Hsu and B. K.Tanner
Fig. 9 Projection topograph of a twin boundary Fig. 10 Projection topograph of Si web dendrite in as grown state in a Si crystal wafer ; = [333]
MoKa, A edge-type total dislocation , $=l[liOl II B 600_ (1 (1 C I! 11 II II 1 g:$;y,' 1 edge-type Shockley partial di%locatjon.
2 edge- "
I(
,I
b=1[2111 B dislocation, Lr [i2ii g
dislocatjon, k;r1121
Fig. 11 Hydrogen induced defects in a Si crystal annealed lhr at 1000°C AgKa, , 220 reflection
Fig. 12 Relationship between the formation of hydrogen-induced defects and the breakdown of Si-H bonds
X-ray topographic
studies in China
69
The contrast
of defects in X-ray topographs of a-LiI03 under a DC field applied along the caxis has been investigated. The diffraction contrast changed remarkably under the action of applied electrostatic fields. The effect was reversible and the original contrast was restored after the removal of the field. This phenomenon was explained in terms of a decoration of space charges accumulated on the crystal defects whereby the locallattice distortion around the defects was enhanced. (40) X-ray topography was also used to study the fracture process and morphology in three point bending tests of MO single crystals. Variations in a plastic zone in front of the pre-cracks in the fracture process were shown. (41) 3.
Doubleand
Multiple-Crystal Diffractometry
A three dimensional DuMond diagram has been constructed from the consideration of dynamical diffraction theory by Xu and Li. (42) The dispersion of wavelengths, vertical,and horizontal divergences of X-rays have been included to construct a complete diagram as shown in Fig. 13. Such a diagram can be used to analyse the successive diffraction of X-rays by multiple crystals. Xu, Chen and Li (43) used this three dimensional DuMond diagram for the analysis of single-and double- crystal spectrometry and for high precision measurements of the CuKa, line profile. The changes of maximum reflection coefficient,half maxirmm line breadth, integrated reflection
e
e
(a)
(b)
Fig. 13 Three dimensional DuMond diagrams (a) X > 0 (b) X < 0 (X is the angle between diffraction plane and the crystal surface)
the
power and change of lattice plane spacing of some planes in cc-LiIO3 single crystals, under the action of an electrostatic field along the z-axis and x-axis, ha+e been investigated by Liang and Yi (44,45) using double crystal diffractometry with a (n,-n) setting. A possible explanation is suggested in terms of displacement and rotation of the 103-group along and around the z-axis, and the existence of a gradient of lattice constant c under the action of the field. Lattice parameter variationsof YAG crystals doped with Nd have been measured by Gao et al (46) at Changchun Institute of Physics, Academia Sinica using the double-crystal method. It is concluded from the experimental data that the variation of lattice paramter is due to the non-uniform distribution of Nd ions in the crystal. Effects of heat treatment on an ion implanted yttrium irongarnet (YIG) epitaxial layer on a gadolinium gallium garnet (GGG) substrate were studied by means of double crystal diffractometry with an asymmetric setting by Tan (47). Experimental results indicated that ion implantation had increased greatly the lattice mismatch between the epitaxial layer and the substrate, the relation between the lattice mismatch and heat treating temperature being found to be a very complex one.
S.S. Hsu and 6. K.Tanner
70
Double- and trie-crystal diffractometry has been used to investigate the lapping and polishing damage in single crystal wafers of Si, GaAs and GGG. This technique was also applied to the simultaneous determination of flexure, lattice mismatch and composition of Ga AllxAs epitaxial layers on GaAs substrates by Xu and his co-workers (48,49). Very small-x flexures of crystal wafers were measured successfully by Chen et al (50) by means of double crystal diffractometry in a special asymmetrical setting. III.
PRESENT STATUS OF ACTIVITY
In order to give an indication of the level of activity in China at present, in this section we have gathered together data concerning research groups, personnel and facilities. As is evident, there are a large number of scientists active and the facilities at several institutions are of world class. It is clear that the Chinese community will make a major contribution to materials characterization over the next decade, particularly in response to the rapid improvements presently being made in crystal quality. 1.
Research Groups and Facilities
A.
Institute of Physics, Academia Sinica, Beijing
B.
Personnel:
b)
Facilities: Rigaku RU-1000 (6OKW rotating target X-ray generator) with large scale Rigaku Lang camera and TV camera system. Rigaku D.MAX-RA (12 KW generator) with Marconi Lang camera.
Peking University, Beijing a)
C.
D.
E.
F.
G.
Personnel:
Sun Zhang-de*, Liang Jin-guo
University of Iron and Steel Technology, Beijing a)
Personnel:
b)
Facilities:
Jiang Bai-lin*, Sheng Shi-xiong, Xias Zhu-gang Rcgaku D/MAX-RA with A-3 Lang camera, Philip APD-10 Diffractometer set.
Shanghai Institute of Metallurgy, Academia Sinica a)
Personnel: Xu Shun-shing*, Jiang Xiao-long, Li Run-shen, Xu Jing-yang, Yang Chuan-zhing, et al
b)
Fac&ities: Rigaku D/MAX-RA with A-3 Lang camera. Domestic X-ray generators with remote control Lang camera and SIM-I, SIM-2 high precision double-crystal SIM diffractometer, SIM multiple-crystal diffraction set.
Shanghai Institute of Ceramics, Academia Sinica Guo Chang-lin*, Huang Yue-hong
a)
Personnel:
b)
Facilities: Rigaku RU-500 with TV camera system, Rigaku D/MAX-RA with Lang camera for large specimens LGL-8, Rigaku scanning type double-crystal topographic goniometer CN 1518 Bl.
Fujian Institute of Research on the Structure of Matter, Fuzhou, Fujian Zhao Qin-lan*, Chen Jin-chang, Huang Yi-sen.
a)
Personnel:
b)
Facilities: Rigaku generator with Lang camera. Domestic generator with SIM-II high precision double-crystal diffractometer.
Changchun Institute of Physics, Changchun, Jilin a)
*
Mai Zhen-hong*, Cui Shu-fan, Ge Pei-wen, Wu Lan-shing, Zhao Ya-fing, et al
a)
Personnel: Gao Da-chao*, Liu Wei-na*
Group Leader **Shanghai Institute of Metallurgy, Academia Sinica.
X-ray topographic b)
H.
I.
studies in China
71
Facilities:
Rigaku D/MAX-RA with Lang camera and scanning type double-crystal topographic goniometer CN 1518 Bl.
Nanjing University, Nanjing, Jiangsu Jiang Shu-sheng*,Zhou Heng-natir Yang Ping.
a)
Personnel:
b)
Facilities: Rigaku 4180 El fine focus X-ray generator with A-3 Lang camera Rigaku D3F generator with domestic Dan Dong W-l Lang camera Rigaku D/MAX-RB with Marconi Lang camera
Other Institutions
a)
Wuhan University, Wuhan, Hubai
b)
Wuhan Institute of Building Materials, Wuhan,Hubai
Cl
Hebai Institute of Technology, Tianjin
d)
Shanghai Institute of Applied Physics, Academia Sinica
e)
Kunming Institute of Physics, Kunming, Yunnan
f)
Emei Institute of Semiconductor Materials (Rigaku RU-1000 with TV camera system and large specimen Lang camera, double crystal topographic goniometer CN 151 Bl)
2.
Synchrotron radiation X-ray sources
Two synchrotron radiation storage rings are under construction in China. be brought into use within two or three years. A.
Both of them will
BEPC at the Institute of High Energy Physics, Academia Sinica, Beijing
This will be a source parasitic on an electron-positkon intersecting storage ring designed for high energy physics experiments. This machine will operate at a maximum energy between 2.2 and 2.8 GeV with beam current up to 150 mA. It will be a ring of total radius 40 m with five synchrotron radiation beam lines feeding a total of seven experimental stations. In addition to EXAFS, small angle scattering, powder diffraction, diffuse scattering, photoelectron spectroscopy and X-ray lithography, one station will be dedicated to X-ray topography. The station will be situated about 40 m from a 1.8T wiggler magnet and transmitted through a 0.5 mm thick Be window, providing radiation of critical wave length 1.32 from a source 15mm x9 mm (lo values). Initially a white radiation camera will be installed and followed subsequently by a double-crystal camera which can lQe used alternatively with the white radiation camera. With an estimated total flux of 6 x 10 photonsisec at E = 1.8GeV, X = 1.5 8 and 1% band width, this will provide a first class facility which will play an important role in the future development of this field in China. B.
c
This is a storage ring designed to provide synchrotron radiation at lower energy levels. It will be operated at 800 MeV, and will be very useful for lithography, small angle scattering, photoelectron spectroscopy and other spectroscopy, photo-chemistry and photobiology research work. However, with the insertion of superconductor wiggler magnets in the future, experimental stations for X-ray topography and EXAFS will be installed.
*
Group Leader ** Shanghai Institute of Metallurgy, Academia Sinica
72
S.S. Hsu and 6. K.Tanner IV.
CONCLUSIONS
Despite limited information exchange prior to 1978, it is evident that a considerable level of activity existed within China during the two previous decades. This has provided a sound base for the current developments. A 10 day lecture course given by one of us (BKT) at the University of Nanjing in the autumn 1984 attracted over 30 scientists from 19 institutions throughout China, and the book "X-ray Diffraction Topography" by the same author has recently been translated into Chinese. X-ray topography and precision diffractometry are seen as major characterization tools in China and we can be confident that the present rate of expansion will continue for some time to come. A new book in Chinese will appear in 1986.(52) V.
ACKNOWLEDGEMENTS
It is with great pleasure that we thank our friends and colleagues Mai Zhen Hong and Jiang ShuSheng for providing much of the background material used in compiling this article. References 1.
Xu Shun-sheng (S.S. Hsu), X-ray Diffraction by Metals (book), Shanghai Publishing House of Science and Technology, (1962).
2.
Xu Shun-sheng (S.S. Hsu), Yang Chuan-zheng and Tan Song-sheng, Direct observation and analysis of dislocations in germanium crystals by means of Borrmann X-ray topography. Presented to the First National Conference on Defects in Crystals and Strength of Metals, Nov. 1964, Nanjing, China.
3.
Sun Zhang-de, Solving the equations of X-ray diffraction by Green function, Acta Phys. Sinica, 32, 982, (1983)
4.
Sun Zhang-de, Solution of the equation of X-ray diffraction by Green function in Bragg case, Acta Phys. Sinica, 21, 1460 (1983).
5.
T. Uragami, J. Phys. Sot. Jpn., 27_, 147 (1969); 28, 1508 (1970);
6.
T. Saks, T. Katagawa and N. Kato, Acta Cryst., e,
7.
Z.G. Pinsker, Dynamical Scattering of X-rays in Crystals, Springer-Verlag, Berlin, P.388, (1978).
8.
Ling Bing-chang, Perturbative solution of Takagi equation in X-ray diffraction dynamics in slightly deformed crystal, Acta Phys. Sinica, 2, 1528, (1981).
9.
Sun Zhang-de and Liang Jing-guo, A new method of solving the Takagi equation of the dynamical theory of X-ray diffraction, Acta Phys. Sinica, 30, 344, (1981).
10.
A.Authier, Modern Diffraction and Imaging Techniques in Materials Science, North Holland, Amsterdam 1978.
11.
Sun Zhang-de, On the quantum mechanical equations of X-ray diffraction and theirsolutions Presented to the Third National Conference on X-ray diffraction, NOV. 1985, Chengdu, China.
12.
Jiang Shu-sheng, Fading phenomenon of PendellBsung fringes in X-ray section topography, Acta Phys. Sinica, 2, 1497, (1983).
13.
Hou Ping, Yang Chuan-zheng and Xu Shun-sheng (S.S. Hsu), The observation and analysis of diffraction images of dislocation by dynamical X-ray topography. Presented to the Third National Conference on Defects in Solids, Sept. 1985, Wuhan, China.
14.
Mai Zhen-hong, to be published.
15.
Yang Ping, Jiang Shu-sheng, Zhou Heng-nan and Feng Duan, The X-ray dynamical diffraction images of a twin boundary in naturally occurring quartz crystal. Presented to the Third National Conference on X-ray Diffraction, Chengdu, China; Chn. Phys. Lett., (1986) No. 1.
31, 1141, (1971)
102, 113, (1972); 2,
192, (1973)
X-ray topographic
studies in China
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16.
A. Authier, Phys. Stat. Sol., (a) 1,
17.
N.
18.
S.S. Jiang (Jiang Shu-sheng) and A.R. Lang, Proc. Roy. Sot. Lond., e,
19.
Mai Zhen-hong, Cui Shu-fan, Fu Quan-gui, Liu Ru-gan and Zhang Jin-fu, Observation on "as grown" microdefects in CZ silicon single crystal, Acta Phys. Sinica, 32, 686, (1983).
20.
Zhen Shi-hai and Mai Zhen-hong. The optical processing of X-ray topographs for the direct observation of micro-defects in silicon crystals, Kexue Tongbao, 27, 1231, (1982).
21.
Xu Shun-sheng (S.S. Hsu), Yang Chuan-zheng and Jiang Xiao-long. The structure of and the defects in the twin interface of silicon single crystal, Chn. J. Semiconductor, 3, 270, (1982).
22.
Yang Chuan-zheng, Jiang Xiao-long and Xu Shun-sheng (S.S. Hasu), X-ray topographic study of dislocations and stacking faults in silicon web dendrites, Acta Phys. Sinica, 2, 341, (1980).
23.
Cui Shu-fan, Ge Pei-wen, Zhao ya-qin and Wu Lan-sheng. The presence of Si-H bonds in Si single crystals and its influence, Acta Phys. Sinica, a, 791 (1979).
24.
Cui Shu-fan, Mai Zhen-hong and Qian Lin-zhao (L.C. Tsien). The Si-H bonds and H-induced defects in single crystal of silicon, Scientia Sinica &l (1983), 1033 (in Chinese); g, 213 (in English).
25.
Mai Zhen-hong, Cui Shu-fan, Li Jian and Ln Yan Study of hydrogen induced defects in floating zone silicon grown in hydrogen atmosphere, Acta Phys. Sinica, 22, 921, (1984)
26.
Jiang Bai-lin, Sheng Shi-xiong and Xiao Zhi-gang. Mechanism of the formation of the defects during heat treatment in single silicon crystal grown in floating zone method under pure hydrogen, Acta Phys. Sinica, 9, 1283, (1980).
27.
Yang Chuan-zheng and Zhu Jian-sheng. Investigation of the defects in silicon single crystal grown by floating-zone method in the atmosphere containing hydrogen, Acta Phys. Sinica, 21, 278, (1982).
28.
Zhong Wei-zhuo. The crystallization habit and defects of synthetic quartz, Acta Phys. Sinica, 2, 240, (1979).
29.
Mai Zhen-hong, Ge Pei-wen, Cui Shu-fan and Wu Lan-sheng. The observation of defects in synthetic quartz by X-ray topography, Acta Phys. Sinica, 30, 1106 (1981).
30.
Zhou Heng-nan and Jiang Shu-sheng, X-ray diffraction topographic study of crystal defect in LiNbO 3, Acta Phys. Sinica, 9, 374 (1980).
31.
Guo Chang-ning and Huang Yue-hong, X-ray topographic sutdy of LiNb03: Kexue Tongbao, 25, 206 (1980).
32.
Mai Zhen-hong, Ge Pei-wen, Cui Shu-fan, Xiao Nan and Wu Lan-sheng. The observation on defects in YAG single crystal by X-ray transmission topography, Acta Phys. Sinica, 30, 999 (1981).
33.
Gao Da-chao, Cui Yu-shun, Li Mei et al. The observation of defects in YAG crystals using double crystal topography. Presented to the Third National Conference on Defects in Solids, Sept. 1985, Wuhan, China.
34.
Jiang Bai-lin, Xu Bin, Liu Xi-lin and Han Jian-ru. X-ray diffraction topography study of defects in AlP04 crystals, Acta Phys. Sinica, 36, 1229, (1985).
35.
Jiang Shu-sheng and Li Qi. X-ray topographic study of defects in beryl. Presented to the Third National Conference on X-ray Diffraction. Nov. 1985, Chengdu, China.
77
(1968).
Kato, Adv. X-ray Anal., lo, 46 (1967). 249 (1983)
Fe crystal,
74
S. S. Hsu and 6. K.Tanner
36.
Zhao Qin-lan, X-ray topographic study of the imperfections in KAP crystal, Presented to the Third National Conference on Defects in Solids, Sept. 1985, Wuhan, China.
37.
Zhao Qin-lan, The dislocation contrast in X-ray diffraction topographs of absorbing crystal KAP. Presented to the Third National Conference on X-ray Diffraction, Nov. 1985, Chengdu, China.
38.
Yu Fu-ju, X-ray topographic examination of defects in ternary Hg0.8Cdo 2Te and Pb0.8Sno 2Te single crystals, Wuli (Physics, Bimonthly), 2 508 (1980):
39.
Su Yi, The observation of crystal defects in Hg,_,Cd Te using X-ray topography. Presented to the Third National Conference on X-ray Diffraction, Nov. 1985, Chengdu, China.
40.
Gu Yuan-xin, Ge Pei-wan, Zhao Ya-qin, Hu Bo-qing, Wu Lansheng and Fu Quan-gui, X-ray topographical study on defects in a-LiIO3 decorated by space charge due to the applied fields, Acta Phys. Sinica, 2, 711 (1980).
41.
An Zheng-zhi and Ha Kuan-fu, An X-ray diffraction topographic method and its applicatior to fracture problem of metal, Acta Met. Sinica, 18, 286.
42.
Xu Shun-sheng (S.S. Hsu) and Li Run-shen, The three dimensional dynamic DuMond diagram for X-ray diffraction analysis of nearly perfect crystal. Presented to the Third National Conference on X-ray Diffraction, Nov. 1985, Chengdu, China.
43.
Xu Shun-sheng (S.S. Hsu), Chen Jing-yi and Li Run-sheng. Analysis of single- and double-crystal spectrometry using three dimensional DuMond diagrams and the high precision measurement of CuK,l line profile, ibid.
44.
Liang Jing-kui and Yi Sun-sheng, An X-ray double crystal spectrometric investigation of the behaviour of a-LiI03 single crystals under the action of electro-static field, Acta Phys. Sinica, 7, 126 (1978).
45.
Yi Sun-sheng and Liang Jing-kui, Variation of lattice constants in the a-LiI03 single crystal under the action of an electrostatic field, Acta Phys. Sinica, g, 314 (1978)
46.
Gao Da-chao, Li Mei, Lou Tai-ping and Cui Yu-shun, The measurement of lattice parameter variation of YAG crystal using double crystal topography. Presented to the Third National Conference on X-ray Diffraction, Nov. 1985, Chengdu, China.
47.
Tan Ru-huan, The Study of heat treatment of GGG crystal after ion implantation by means of X-ray double crystal diffractometry, ibid.
48.
Xu Shun-sheng (S.S. Hsu), Xu Jing-yang and Tan Ru-huan. Investigation methods of lappir and polishing damages in single crystal wafers by X-ray double and triple-crystal diffractometry, Chn. J. Semiconductor, 2, 95 (1982).
49.
Xu Jing-yang, Tan Ru-huan and Xu Shun-sheng (S.S. Hsu), Simultaneous determination of fletire, lattice mismatch and composition of Gal_xA1,As epitaxial layer on GaAs by mean: Presented to the Second National Conference on X-ray of double-crystal diffractometry. Diffraction, Dec. 1982, Shanghai, China.
50.
Chen Jing-yi, Li Run-shen and Xu Shun-sheng (S.S. Hsu), The measurement ofsvery small flex ure in crystal wafers using double-crystal diffractometry with (n", n ) setting. Presented to the Third National Conference on X-ray Diffraction, Nov. 1985,
51.
Zhou Heng-nan, X-ray topographic study of twin boundaries in natural n-quartz, Acta Mineral, Sinica, 5, 254, (1985).
52.
Xu Shun-sheng and Feng Duan (eds.) Press, Beijing, 1986.
X-ray Diffraction Contrast Topography, Science
X-ray topographic
studies in China
THE AUTHORS
Xu Shun Sheng received his B.S. degree from the National Wuhan University of China in 1943 and his Ph.D. from the University of Notre Dame, U.S.A. in 1953. He is Research Professor of Materials Science and X-ray diffraction at the Shanghai Institute of Metallurgy, Academia Sinica and Chairman of the X-ray diffraction committee of the Chinese Society of Physics. Brian K. Tanner received his B.A. degree from Oxford University in 1968, gaining a D. Phil. from the same university in 1972. He is Reader in Physics at the University of Durham, a Director of Bede Scientific Instruments and a Fellow of the Institute of Physics.
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