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Focused ion beam technology
Classified abstracts 6574 6582 source, titanium tetrakis-(dimethylamide), resulted in the formation of carbonitride powders. M R Hilton et al, Thin Solid Films, 154, 1987, 377 386. 23 6574. Characterization of plasma-deposited silicon nitride coating used for integrated circuit encapsulation The origin of instability observed in n-channel metal~)xide-semiconductor field effector transistor (MOSFET) devices encapsulated with plasma-deposited silicon nitride films prepared from a m m o n i a silane (2% in nitrogen) gas mixture was investigated. The physical, chemical and structural properties of these films are compared with those of films prepared by reaction of a m m o n i a and silane without nitrogen. Auger electron spectroscopy and X-ray photoelectron spectroscopy measurements revealed compositional and structural differences in the films prepared fiom these two processes. Fourier transform IR measurements show that, for the 100% Sill 4 process, 78% of hydrogen is bonded to silicon and 22% to nitrogen, while for the 2% Sill 4 process almost all (94%) of the hydrogen is bonded to nitrogen and only 6% to silicon. It is suggested that these N - H and Si H bonds are broken during the subsequent plasma etching process, resulting in dangling bonds which are responsible for generating more positive trapped charges in the silicon nitride films, thus affecting the threshold voltage of the n-channel MOSFETs. Vineet S Dharmadhikari, Thin Solid Films, 153, 1987, 459~[68. 23 6575. Preparation and properties of cubic boron nitride coatings Cubic boron nitride (CBN) has attracted a great deal of interest in recent years for its unique mechanical and optical properties. M a n y physical as well as chemical vapor deposition processes have been explored to synthesize C B N coatings. These techniques, however, suffer limitations owing to the requirements of high substrate temperature and/or the necessity of using toxic starting materials. We have developed a new technique where C B N films can be prepared by evaporating boric acid in NH3 plasma. C B N films have been deposited at substrate temperatures as low as 450°C. Structure and optical and electrical characteristics of the films clearly demonstrate the simple cubic phase in the coatings. These results are presented in this paper. P Lin et al, Thin Solid Films, 153, 1987, 487~496. 23 6576. Cathodic arc plasma deposition of TiC and TiC,N1_ x This paper deals with the reactive deposition of TiC and TiCxNz-x films using the cathodic arc plasma deposition process. TiC films were prepared by a reactive deposition involving titanium and c a 4 gas, whereas TiCN films were prepared using titanium and a mixture of CH4 and N2 gases. The films were analyzed for microhardness, adhesion, crystal structure and composition. The TiC films deposited at temperatures of 500°C and below were found to contain significant a m o u n t s of hydrogen whereas films deposited above 600°C were virtually free of hydrogen. The wear characteristics were markedly affected by the presence of hydrogen in the films. TiCxNt x films with x ~ 0.15~0.30 were found to be superior to TiN films in actual cutting tests. The erosion test on TiC films deposited at temperatures of 600°C and above indicates these coatings to be superior to TiN films. H Randhawa, Thin Solid Films, 153, 1987, 209-218. 23 6577. Structure, properties and applications of TiN coatings produced by sputter ion plating The potential beneficial effects that wear-resistant coatings have on engineering surfaces depends upon their ability to remain adherent with the treated component. This paper concentrates on the process of sputter ion plating, a simple dc glow discharge sputtering system operating in soft vacuum, and relates the properties of titanium nitride coatings to the degree of ion polishing (substrate bias) which is utilised during deposition. Substrate bias was identified as the most important system parameter since it allowed for some stress relaxation within the coating via its influence on porosity levels in the coating microstructure. The influence that this has on coating adhesion is discussed. The internal stress is a combination of intrinsic growth stresses and thermal mismatch stresses with the latter tending to dominate as substrate bias is increased. In addition to substrate bias, the role that titanium interlayers and substrate cleaning play in improving the adhesion of titanium nitride coatings is discussed, and the potential benefits highlighted. In the last part of the 504
paper some applications of titanium nitride coating are described--it will be shown that increase in component life is by no m e a n s the only criterion which should be considered when judging the success, or otherwise, of a coated component. D S Rickerby and R B Newbery, Vacuum, 38, 1988, 161 166. 23 6578. Ceramic coatings produced by means of a gas tunnel-type plasma jet A gas tunnel-type plasma jet has a higher temperature than any other plasma jets; a high-power stabilized plasma beam can be easily obtained. Moreover, it is possible to inject various materials from the center electrode toward the center of this plasma beam. These properties of the gas tunnel-type plasma jet apparatus are of great advantage to the application to the thermal spraying of high melting point materials such as ceramics. The fundamental characteristics o f this new type of plasma spraying apparatus were determined through experimentation, and a variety of ceramic coatings produced using this apparatus were studied. Since this system is very effective in heating and melting sprayed powder, highquality ceramic coatings can be easily produced even at a small power using argon as the working gas. At 30 k W or more, the Vickers hardness of the various ceramic coatings is 30% greater than that produced with a conventional-type plasma spraying apparatus. For example, a Vickers hardness value of 1200 has been achieved for A1203 coatings. Yoshiaki Arata et al, J appl Phys, 62, 1987, 488~4889.
III. Particle beam technology and processing of materials 30. P A R T I C L E BEAMS A N D S O U R C E S 30 6579. Focused ion beam technology A focused ion beam system was developed for maskless, direct write patterning of feature sizes as small as 0.1 /zm. The processes used are compatible with ASIC fabrication requirements and prototype device manufacture. Yukinori Ochiai et al, Solid State Technol, 30, 1987, 75 79. 30 6580. Electron beam direct writing technology: system and process This paper describes a nanometric lithography system capable of writing a 0.1 p m ULSI chip with practical throughput and high accuracy. A 30 n m beam spot at a 3 nA current is obtained using a Ti/W(100) thermal field emitter. Challenges relating to resist materials and processes are discussed. Norio Saitou et al, Solid State Technol, 30, 1987, 65-70. 30 6581. Characterization of a reactive broad beam radio-frequency ion source To overcome the problems of reactive gases on the lifetime of de-ion sources for etching and deposition applications a capacitively coupled radio frequency (rf)-ion source has been developed. Details on the source characteristics will be given. The excitation of the ion-source plasma is achieved by an electrical rf field at 27.12 MHz. Different if-electrode configurations are used. The plasma density is enhanced by a multipolar magnetic field. The ion beam is extracted by a multiaperture thrce-grid optics to obtain higher ion currents at low-ion energies. At a if-power of 500 W for oxygen the 2-in. beam diameter leads to an ion current of 40 m A which is equivalent to 2 m A / c m 2. Data on the beam divergence and the ion energy of the beam have been taken. A divergence of 2.3 ° could be measured. Different reactive and nonreactive gases were tested and the source operates without lifetime problems. R Lossy and J Engemann, J Vac Sci Technol, B6, 1988, 284~287. 30 6582. Production of atomic or molecular nitrogen ion beams using a multicusp and a microwave ion source Two small ion sources have been used to generate positive nitrogen ion beams. One is a multicusp ion source, the other is a compact microwave ion source which needs no magnetic field for operation. Both sources are operated with and without a magnetic filter to control the energetic electron population near the extraction region. Results for both ion sources, including current densities and ionic species mix are presented.
paper some applications of titanium nitride coating are described--it will be shown that increase in component life is by no m e a n s the only criterion which should be considered when judging the success, or otherwise, of a coated component. D S Rickerby and R B Newbery, Vacuum, 38, 1988, 161 166. 23 6578. Ceramic coatings produced by means of a gas tunnel-type plasma jet A gas tunnel-type plasma jet has a higher temperature than any other plasma jets; a high-power stabilized plasma beam can be easily obtained. Moreover, it is possible to inject various materials from the center electrode toward the center of this plasma beam. These properties of the gas tunnel-type plasma jet apparatus are of great advantage to the application to the thermal spraying of high melting point materials such as ceramics. The fundamental characteristics o f this new type of plasma spraying apparatus were determined through experimentation, and a variety of ceramic coatings produced using this apparatus were studied. Since this system is very effective in heating and melting sprayed powder, highquality ceramic coatings can be easily produced even at a small power using argon as the working gas. At 30 k W or more, the Vickers hardness of the various ceramic coatings is 30% greater than that produced with a conventional-type plasma spraying apparatus. For example, a Vickers hardness value of 1200 has been achieved for A1203 coatings. Yoshiaki Arata et al, J appl Phys, 62, 1987, 488~4889.
III. Particle beam technology and processing of materials 30. P A R T I C L E BEAMS A N D S O U R C E S 30 6579. Focused ion beam technology A focused ion beam system was developed for maskless, direct write patterning of feature sizes as small as 0.1 /zm. The processes used are compatible with ASIC fabrication requirements and prototype device manufacture. Yukinori Ochiai et al, Solid State Technol, 30, 1987, 75 79. 30 6580. Electron beam direct writing technology: system and process This paper describes a nanometric lithography system capable of writing a 0.1 p m ULSI chip with practical throughput and high accuracy. A 30 n m beam spot at a 3 nA current is obtained using a Ti/W(100) thermal field emitter. Challenges relating to resist materials and processes are discussed. Norio Saitou et al, Solid State Technol, 30, 1987, 65-70. 30 6581. Characterization of a reactive broad beam radio-frequency ion source To overcome the problems of reactive gases on the lifetime of de-ion sources for etching and deposition applications a capacitively coupled radio frequency (rf)-ion source has been developed. Details on the source characteristics will be given. The excitation of the ion-source plasma is achieved by an electrical rf field at 27.12 MHz. Different if-electrode configurations are used. The plasma density is enhanced by a multipolar magnetic field. The ion beam is extracted by a multiaperture thrce-grid optics to obtain higher ion currents at low-ion energies. At a if-power of 500 W for oxygen the 2-in. beam diameter leads to an ion current of 40 m A which is equivalent to 2 m A / c m 2. Data on the beam divergence and the ion energy of the beam have been taken. A divergence of 2.3 ° could be measured. Different reactive and nonreactive gases were tested and the source operates without lifetime problems. R Lossy and J Engemann, J Vac Sci Technol, B6, 1988, 284~287. 30 6582. Production of atomic or molecular nitrogen ion beams using a multicusp and a microwave ion source Two small ion sources have been used to generate positive nitrogen ion beams. One is a multicusp ion source, the other is a compact microwave ion source which needs no magnetic field for operation. Both sources are operated with and without a magnetic filter to control the energetic electron population near the extraction region. Results for both ion sources, including current densities and ionic species mix are presented.