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Hialvac and Teflon outgassing under ultra-high vacuum conditions
Classified abstracts 4619-4629 composition of the oxide film that forms during ambient and low pressure oxidation. The alloy surface is, on the average, enriched in lead. The leadrich phase is preferentially sputtered during ion etching. Tin in the alloy surface oxidizes preferentially; however, if the conditions are such that the alloy surface layer becomes-depleted in tin, lead will be oxidized. R P Frnnkenthal and D J Siconolfi. J Vat Sci Technol. 17 (6). .,. 1980. 13151319. 33. NUCLEONICS 33
4619. Observation a position-sensitive
of X-ray Raman, Compton and plasmon proportional counter. (GB)
scattering
using
Using the combination of a curved crystal analyser and a positionsensitive detector, we derqonstrate how an energy resolution of a few eV in theenergy range of 10 keV can be achieved without sulfering a prohibitive loss in the observed intensity. In this preliminary report we describe an experimental set-up in which spectra from Raman, Compton and plasmon scattering can be collected in a matter of hours using monochromatic CuKcr, radiation from a 1.0 kW X-ray generator. After scattering in either a Be or a graphite target, the X-rays were reflected from the (333) planes of a curved Ge crystal and brought to a focus on a position sensitive proportional counter. In the case of Be, data were collected for three different scattering angles in order to illustrate the various scattering processes which can occur in this region of energy and momentum transfer. The measurements on pyroliticgraphite confirm earlier reports of a striking anisotropy in the spectral distribution of the scattered X-rays, depending upon the direction of the experimental scattering vector relative to the basal planes in this layered crystal. The anisotropy arises from the strong directional dependence of the cross section for plasmon excitation in graphite. Some straightforward improvements to the present apparatus would lead to an increase in the observed intensity by a factor of 40 or more. (Germany) P Pattison et al, J Phys E: Sci Insrrum, 14 (I), 1981, 95-99. 33
A simple, inexpensive tape system nuclei transported by He jet. (GB)
4620.
for on-line
studies
33
laser isotope separation is presented. Using an analytically solvable model and a numerical simulation we have found that the scheme can meet the rather severe time and space restrictions imposed by the large cross-section for charge exchange. (Israel) G Hazak et al, J Appl Phys, 51 (lo), 1980, 5207-521 I.
of chromium
film and its novel etching
mode. (USA) The influence-s of chromium and chromium oxide films and gas compositions on plasma etching characteristics were investigated. Oxygen as well as chlorine is found to be responsible for etching. One possible etching reaction is proposed, in which a basic reaction product is assumed to be CrO#Zl, which will be volatile in gas plasma. The impurities such as W. Fe, and Cu contained in the film become non-volatile compounds which accumulate on the surface of the film and form a masking layer resulting in a suppression of the reaction. Anomalous etching modes called the contour and reverse etches were found with the chromium oxide films containing tungsten impurities. The mechanisms of these anomalous etching modes is discussed, in which the accumulation of the tungsten compounds on the surface of the film is a basic mechanism. The reverse etch mode was applied to the fabrication of photomasks for MOS LSI. (Japan) H Nakata et al, J Vat Sci Technol, 17 (6). 1980. 1351-1357. 35
(Netherlands) Until recently the electrodeposition of aluminium on a conducting substrate was only very rarely put to practical use. This was mainly because the deposition had to be carried out in a highly flammable organic solvent. Electrochemical studies at Philips Research Laboratories have now led to the discovery of a much less dangerous solvent. The laboratories are now co-operating with the Centre for Metal Chemistry and Coatings-part of the Philips Plastics and Metalware Factories (PMF)-in an investigation of the industrial feasibility of the process in a pilot production scheme, and are trying out various likely applications for electrodeposited aluminium. J F M van de Berg et al, Philips Tech Rev. 39 (3/4), 1980, 87-91. 4625.
The electrodeposition
4626.
Hialvac
of aluminium.
and Teflon
outgassing
under ultra-high
vacuum
conditions
GW
A quadrupole mass spectrometer was used to determine the outgassing characteristics of Hialvac glaze and Teflon by analysing the residual gases in an ultra-high vacuum (10e9/Pa range) system.The main gases evolved by a sample of extruded Teflon were H,O, CO and CO,. The outgassing from Hialvac glaze and machined Teflon was below the detectable limit. (South Africa) K F Poole and M M Michaelis, Vacuum, 30 (10). 1980, 415-417. 35
(USA) One of the concerns in using titanium diboride (TiB,) and titanium carbide (Tic) in the high vacuum environment of a plasma vesselis the gas release characteristics. Total outgassing rate and mass spectra measurements have been conducted on these materials at room temperature, 100°C and 250°C and the results are presented. J H Craig Jr, J Vat Sci Technol, 17 (6), 1980, 1377-1378. 4627.
Outgassing
characteristics
of TIC and TiB,
coated graphite.
OF MATERIALS 35
Surface texturing of copper solar selective absorbing surfaces.
4622.
by sputter
etching
with applications
and G L Harding,
J Vat Sci Technol,
17 (6), 1980,132&1325. 35
Etching and film formation in CF,Br observations and their general implications.
plasmas:
wrne
36. PARTICLE
BEAMS AND SOURCES 36
for
(USA) Solar selective absorbing surfaces have been produced by texturing copper specimens in a novel magnetron cosputtering system which allows high rate sputter etching of a moving metal plate seeded with low sputter rate material. Unusual topographical features have been produced on copper in this apparatus using titanium seed. The variation of optical properties and surface morphology of the copper as a function of sputter etching conditions has been studied. Typical selective surfaces produced have absorbances 01- 0.90 and emittances E’- 0.10 at 300 K. (Australia)
4623.
Plasma etching characteristics
35
4621. Fast ion extraction in laser isotope separation. (USA) An analysis of the E x B scheme for fast ion extraction in
P M Curmi
35 4624.
of short-lived
A simple tape transport systemis described which is used for the collection of short-lived nuclides emerging from an He-jet recoil transport system. It is based on pistons driven by compressed air and is both inexpensive and reliable, and allows accurate and reproducible positioning of the radioactive sources at the counting position. F Griffirhs and W Celletly, J Phys E: Sci fnsrrum, 14 (I), 1981. 29-30.
35. PROCESSING
overlays a monolayer of bromine at the silicon interface, but negligible bromine is incorporated into the fluorocarbon. Some chemical mechanisms which account for these observations are presented. D L Flamm et al, J Vat Sci Technol, 17 (6). 1980, 1341-1347.
qualitative
(USA) CF,Br plasma discharges exhibit a number of unusual phenomena. Under some conditions silicon and SiO, can be concurrently etched, while in other circumstances only SiO, is etched and silicon is coated with a uniform, cross-linked fluorocarbon film. Single crystal n-doped silicon is etched more rapidly than undoped silicon. The fluorocarbon polymer
(GB) A simple ion gun, which efficiently operate-s at the pressure range from 13.33-1.33 mPa (lO-“ to IO-’ torr) and in the energy range from 250 to 1000 eV, has been devised for ISS applications. Mass analyses show that when the source is operated with 99.99% grade gases (Ar, Ne and He) the ratio of the doubly-charged ion to the singly-charged one for Ne and Ar is 0.02 and 0.16, respectively, and the amount of other impurities which consist of CO+ and H,O+ is about 2% of the total ions. Intensity curves of singlycharged ions in each case have a broad maximum at the pressure around 53.32 mPa (4 x 10m4 torr). The energy spread is found to be 0.99 eV for an He’ ion beam by extrapolation to zero beam energy. An application to ISS study is also presented. (Japan) F Sboji and T Hanawa, J Phys E: Sci frrsrrum, 14 (I), 1981. 91-94. 4628.
A simple
low-energy-spread
ion gun utilising
a B-A gauge.
36
4629.
Cross-sections
for
elastic
collisions
in cesium
gas interactions.
(Canada) The shift and broadening constants for D,, D, lines of Cs noble gas and Cs light molecular gas (H2, N,) systemsare reported. The total cross-section for elastic collisions is calculated from our experimental results. Some 211
4619. Observation a position-sensitive
of X-ray Raman, Compton and plasmon proportional counter. (GB)
scattering
using
Using the combination of a curved crystal analyser and a positionsensitive detector, we derqonstrate how an energy resolution of a few eV in theenergy range of 10 keV can be achieved without sulfering a prohibitive loss in the observed intensity. In this preliminary report we describe an experimental set-up in which spectra from Raman, Compton and plasmon scattering can be collected in a matter of hours using monochromatic CuKcr, radiation from a 1.0 kW X-ray generator. After scattering in either a Be or a graphite target, the X-rays were reflected from the (333) planes of a curved Ge crystal and brought to a focus on a position sensitive proportional counter. In the case of Be, data were collected for three different scattering angles in order to illustrate the various scattering processes which can occur in this region of energy and momentum transfer. The measurements on pyroliticgraphite confirm earlier reports of a striking anisotropy in the spectral distribution of the scattered X-rays, depending upon the direction of the experimental scattering vector relative to the basal planes in this layered crystal. The anisotropy arises from the strong directional dependence of the cross section for plasmon excitation in graphite. Some straightforward improvements to the present apparatus would lead to an increase in the observed intensity by a factor of 40 or more. (Germany) P Pattison et al, J Phys E: Sci Insrrum, 14 (I), 1981, 95-99. 33
A simple, inexpensive tape system nuclei transported by He jet. (GB)
4620.
for on-line
studies
33
laser isotope separation is presented. Using an analytically solvable model and a numerical simulation we have found that the scheme can meet the rather severe time and space restrictions imposed by the large cross-section for charge exchange. (Israel) G Hazak et al, J Appl Phys, 51 (lo), 1980, 5207-521 I.
of chromium
film and its novel etching
mode. (USA) The influence-s of chromium and chromium oxide films and gas compositions on plasma etching characteristics were investigated. Oxygen as well as chlorine is found to be responsible for etching. One possible etching reaction is proposed, in which a basic reaction product is assumed to be CrO#Zl, which will be volatile in gas plasma. The impurities such as W. Fe, and Cu contained in the film become non-volatile compounds which accumulate on the surface of the film and form a masking layer resulting in a suppression of the reaction. Anomalous etching modes called the contour and reverse etches were found with the chromium oxide films containing tungsten impurities. The mechanisms of these anomalous etching modes is discussed, in which the accumulation of the tungsten compounds on the surface of the film is a basic mechanism. The reverse etch mode was applied to the fabrication of photomasks for MOS LSI. (Japan) H Nakata et al, J Vat Sci Technol, 17 (6). 1980. 1351-1357. 35
(Netherlands) Until recently the electrodeposition of aluminium on a conducting substrate was only very rarely put to practical use. This was mainly because the deposition had to be carried out in a highly flammable organic solvent. Electrochemical studies at Philips Research Laboratories have now led to the discovery of a much less dangerous solvent. The laboratories are now co-operating with the Centre for Metal Chemistry and Coatings-part of the Philips Plastics and Metalware Factories (PMF)-in an investigation of the industrial feasibility of the process in a pilot production scheme, and are trying out various likely applications for electrodeposited aluminium. J F M van de Berg et al, Philips Tech Rev. 39 (3/4), 1980, 87-91. 4625.
The electrodeposition
4626.
Hialvac
of aluminium.
and Teflon
outgassing
under ultra-high
vacuum
conditions
GW
A quadrupole mass spectrometer was used to determine the outgassing characteristics of Hialvac glaze and Teflon by analysing the residual gases in an ultra-high vacuum (10e9/Pa range) system.The main gases evolved by a sample of extruded Teflon were H,O, CO and CO,. The outgassing from Hialvac glaze and machined Teflon was below the detectable limit. (South Africa) K F Poole and M M Michaelis, Vacuum, 30 (10). 1980, 415-417. 35
(USA) One of the concerns in using titanium diboride (TiB,) and titanium carbide (Tic) in the high vacuum environment of a plasma vesselis the gas release characteristics. Total outgassing rate and mass spectra measurements have been conducted on these materials at room temperature, 100°C and 250°C and the results are presented. J H Craig Jr, J Vat Sci Technol, 17 (6), 1980, 1377-1378. 4627.
Outgassing
characteristics
of TIC and TiB,
coated graphite.
OF MATERIALS 35
Surface texturing of copper solar selective absorbing surfaces.
4622.
by sputter
etching
with applications
and G L Harding,
J Vat Sci Technol,
17 (6), 1980,132&1325. 35
Etching and film formation in CF,Br observations and their general implications.
plasmas:
wrne
36. PARTICLE
BEAMS AND SOURCES 36
for
(USA) Solar selective absorbing surfaces have been produced by texturing copper specimens in a novel magnetron cosputtering system which allows high rate sputter etching of a moving metal plate seeded with low sputter rate material. Unusual topographical features have been produced on copper in this apparatus using titanium seed. The variation of optical properties and surface morphology of the copper as a function of sputter etching conditions has been studied. Typical selective surfaces produced have absorbances 01- 0.90 and emittances E’- 0.10 at 300 K. (Australia)
4623.
Plasma etching characteristics
35
4621. Fast ion extraction in laser isotope separation. (USA) An analysis of the E x B scheme for fast ion extraction in
P M Curmi
35 4624.
of short-lived
A simple tape transport systemis described which is used for the collection of short-lived nuclides emerging from an He-jet recoil transport system. It is based on pistons driven by compressed air and is both inexpensive and reliable, and allows accurate and reproducible positioning of the radioactive sources at the counting position. F Griffirhs and W Celletly, J Phys E: Sci fnsrrum, 14 (I), 1981. 29-30.
35. PROCESSING
overlays a monolayer of bromine at the silicon interface, but negligible bromine is incorporated into the fluorocarbon. Some chemical mechanisms which account for these observations are presented. D L Flamm et al, J Vat Sci Technol, 17 (6). 1980, 1341-1347.
qualitative
(USA) CF,Br plasma discharges exhibit a number of unusual phenomena. Under some conditions silicon and SiO, can be concurrently etched, while in other circumstances only SiO, is etched and silicon is coated with a uniform, cross-linked fluorocarbon film. Single crystal n-doped silicon is etched more rapidly than undoped silicon. The fluorocarbon polymer
(GB) A simple ion gun, which efficiently operate-s at the pressure range from 13.33-1.33 mPa (lO-“ to IO-’ torr) and in the energy range from 250 to 1000 eV, has been devised for ISS applications. Mass analyses show that when the source is operated with 99.99% grade gases (Ar, Ne and He) the ratio of the doubly-charged ion to the singly-charged one for Ne and Ar is 0.02 and 0.16, respectively, and the amount of other impurities which consist of CO+ and H,O+ is about 2% of the total ions. Intensity curves of singlycharged ions in each case have a broad maximum at the pressure around 53.32 mPa (4 x 10m4 torr). The energy spread is found to be 0.99 eV for an He’ ion beam by extrapolation to zero beam energy. An application to ISS study is also presented. (Japan) F Sboji and T Hanawa, J Phys E: Sci frrsrrum, 14 (I), 1981. 91-94. 4628.
A simple
low-energy-spread
ion gun utilising
a B-A gauge.
36
4629.
Cross-sections
for
elastic
collisions
in cesium
gas interactions.
(Canada) The shift and broadening constants for D,, D, lines of Cs noble gas and Cs light molecular gas (H2, N,) systemsare reported. The total cross-section for elastic collisions is calculated from our experimental results. Some 211