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265. Simple acoustic vacuum indicator and leak detector
Classified abstracts 259--276 26 : 22 Automatic recording McLeod gauge. See abstract number 238. 26 259. Thermal transpiration using ultra-high vacuum techniques.
(Canada) T Edmonds and J P Hobson, J Vac Sci Techn, 2 (4), 1965, 182-197. 26:21 260. Automatic control 6f variable speed pump drives. (Germany) The article reviews various methods o f driving pumps from the point of view of operational efficiency and the requirement of the hydraulic system. Typical electrical automatic control systems are described, generally based on proportional zone control, using a multimotor level control system as an example. (Great Britain) J C H Jones, Pumps, 3, May 1965, 166-174.
pressure in the mass spectrometer was 5 × 10 -8 tort and 10 -s tort in the vacuum lock. Sealing arrangements eliminate background ion currents from an untrapped oil diffusion pump. Momentary pressure surges occurring in the mass tube during sample change-over (maximum surge observed was 10 -5 torr) did not affect the ultimate vacuum which was re-established in 10 to 15 minutes. G A Junk and H J Svec, Anal Chem, 37 (12), Nov 1965, 1629-1630.
III. V a c u u m a p p l i c a t i o n s 30. Evaporation and sputtering 30 269. Formation of permalloy films using a high-vacuum ion source.
(USSR)
27. Leak detectors and leak detection 261. An inverted magnetron helium leak detector. (USA) R F K Herzog and W P Poschenrieder, J Vac Sci Teehn, 2 (4), 1965,
The characteristics of a ring and a cylindrical electron gun used m the deposition of thin films in high vacuum are described. E M Dublulna er al, Izv Akad Nauk SSSR, Ser Fiz, 29 (4), 1965,
198-202.
629-633.
27
27 262. Helium leak detector probe. (USA) F C Reynolds, Rev Scient Instrum, 36 (8), 1965, 1260-1261. 27
263. Some experiences with an adsorption leak detector. J Reichel, Exptl Tech Physik, 13 (1), 1965, 56-59.
(Germany)
27 264. The adsorption leak detector equipped with a Pirani gauge coloed in liquid hydrogen. (Germany) F Langen, Exptl Teeh Physik, 13 (1), 1965, 53-55.
27 265. Simple acoustic vacuum indicator and leak detector. (Germany) F Hahaemann, Exptl Tech Physik, 13 (1), 1965, 60. 27 : 37 266. Some results of mass spectrometer investigations on the working mechanism of a halide leak detector. (USSR) The ionization chamber of an MS-3 mass spectrometer was replaced by the sensor element of a halide leak detector. This allowed measurement of the total ion current and the resolution of component currents. Constant pressure at the source and constant temperature o f the emitter was maintained by controlled injection of air into the system. The effect of various gases and vapours other than air was also studied. All ion current measurements were at pressures of 1.5 × 10 -s to 2 × 10 -5 torr but the conclusions may be applied to the whole range of operating pressures of the halide leak detector. The results show that the amplification of the ion current by the halogens is dependent on the presence of alkali metal ions. It is suggested that the halogen ions modify the properties of the incandescent platinum surface towards the neutral alkali atoms which arrive there, originating from the ceramic pipe. The supply of alkali metal ions is soon exhausted and the efficiency of the leak detector is reduced. To remedy this it is recommended that, in the preparations of the emitter, the ceramic is immersed in boiling aqueous alkaline solution and subsequently annealed in air for a few hours. V I Karpov et al, Zh Tekh Fiz, 35 (9), 1663, (in Russian).
3O 270. Ion beam depesition--microelectronic applications. (USA) Demonstration of the feasibility of depositing resistive and conductive patterns on dielectric substrates. A R Wolter, Microelectronics and Rehabihty, 4, 1965, 101-102. 30 271. A CdSe-ZnSe thin film rectifier. (USA) Description of the propert,es of a thin-film rectifier formed on a glass substrate by vacuum-deposition of a graded CdSe-ZnSe film between two deposited gold electrodes. W A Gutierrez and H L Wilson, IEEEProc, 53, 1965, 749.
30 272. Poly-para-xylylene in thin film applications. (USA) The thin films are deposited using an unusual vacuum process m which the crystalline solid is sublimed under vacuum and then pyrolyzed to give a nearly quantitative yield of the reactive intermediate, p-xylylene. F E Carion et al, IEEE Trans on Parts, Materials andPackaging, vo[
PMP-1, 1965, 54-62. 30 : 42
273. Glass coating by vacuum deposition. (USA) Description of processes and applicattons. E M Wiiliamson Jr, Glass lnd, 46 (5), 1965, 262-264.
3O 274. Relation of the epitaxy temperature to the parameters of vacuum deposition. ( USSR) Theoretical considerations are given confirming existing experimental data. S P Svetlov, Kristallografia, 10 (4), 1965, 586-588 30 : 39 275. Solid surfaces in vacuum. (Switzerland) The review of some of the properties of solid surfaces includes some results obtained by low-energy electron diffraction. W Eppreeht, Sehwelz Arch dngew Wiss Tech, 31 (2), 1965, 33-39 30 276. The problem of silicon evaporation in producing epitaxial films.
(USSR) 29. Heating~quipment and thermometers 28 267. Thermocbuple for measuring high temperatures in vacuum and helium. ( USSR) G E Pletenetskii, Zavodsk Lab, 30 (5), 1964, 625-628.
29. Miscellaneous 29 : 37 268. A vacuum lock for the direct insertion of samples into a mass spectrometer. (USA) Commercially available vacuum locks are generally expensive, bulky, require venting for sample changes and lack flexibility in application and operation. A direct insertion vacuum lock which eliminates all these disadvantages is described. It is easily fabricated from a commercial gate valve by modification of the removable end caps. This process is described and illustrated. This device has given completely trouble-free daily operation for the past two years on the General Electric mass spectrometer. In this case, the ultimate
Films obtained from silicon evaporated in crucibles under vacuum are contaminated due to the chemical reactivity of liquid silicon. In the method described contamination was eliminated by use of a melted zone of silicon, held between silicon rod electrodes, by surface tension, as an evaporating source. Silicon was deposited on a p-type single crystal silicon substrate cut parallel to the 111 plane and having a resistivity of 69 ohm/cm. The substrate was heated in 3 0 m i n u t e s t o l 0 0 0 O C u n d e r a v a c u u m o f 2 x I 0 - 6 t o 3 × 10-~torr, using a tantalum heater Single crystal, p-type films, 3 to 4 p thick were obtained with substrate temperatures of 950 to 1100°C. The films showed a resistivity of 0.3 to 0.4 ohm/cm and room temperature Hall mobility of 120 to 130 cm~/sec. Successive stages of epitaxial growth were observed and the triangular shapes appearing in the growth figures Indicate a condensation mechanism o f the vapour --> crystal type. The method has the advantage of simplicity in addition to resolving the film contamination problem. A I Petrin and G A Kurov, Crystallography, 10 (5), 1965, 754, (in
Russian). 107
(Canada) T Edmonds and J P Hobson, J Vac Sci Techn, 2 (4), 1965, 182-197. 26:21 260. Automatic control 6f variable speed pump drives. (Germany) The article reviews various methods o f driving pumps from the point of view of operational efficiency and the requirement of the hydraulic system. Typical electrical automatic control systems are described, generally based on proportional zone control, using a multimotor level control system as an example. (Great Britain) J C H Jones, Pumps, 3, May 1965, 166-174.
pressure in the mass spectrometer was 5 × 10 -8 tort and 10 -s tort in the vacuum lock. Sealing arrangements eliminate background ion currents from an untrapped oil diffusion pump. Momentary pressure surges occurring in the mass tube during sample change-over (maximum surge observed was 10 -5 torr) did not affect the ultimate vacuum which was re-established in 10 to 15 minutes. G A Junk and H J Svec, Anal Chem, 37 (12), Nov 1965, 1629-1630.
III. V a c u u m a p p l i c a t i o n s 30. Evaporation and sputtering 30 269. Formation of permalloy films using a high-vacuum ion source.
(USSR)
27. Leak detectors and leak detection 261. An inverted magnetron helium leak detector. (USA) R F K Herzog and W P Poschenrieder, J Vac Sci Teehn, 2 (4), 1965,
The characteristics of a ring and a cylindrical electron gun used m the deposition of thin films in high vacuum are described. E M Dublulna er al, Izv Akad Nauk SSSR, Ser Fiz, 29 (4), 1965,
198-202.
629-633.
27
27 262. Helium leak detector probe. (USA) F C Reynolds, Rev Scient Instrum, 36 (8), 1965, 1260-1261. 27
263. Some experiences with an adsorption leak detector. J Reichel, Exptl Tech Physik, 13 (1), 1965, 56-59.
(Germany)
27 264. The adsorption leak detector equipped with a Pirani gauge coloed in liquid hydrogen. (Germany) F Langen, Exptl Teeh Physik, 13 (1), 1965, 53-55.
27 265. Simple acoustic vacuum indicator and leak detector. (Germany) F Hahaemann, Exptl Tech Physik, 13 (1), 1965, 60. 27 : 37 266. Some results of mass spectrometer investigations on the working mechanism of a halide leak detector. (USSR) The ionization chamber of an MS-3 mass spectrometer was replaced by the sensor element of a halide leak detector. This allowed measurement of the total ion current and the resolution of component currents. Constant pressure at the source and constant temperature o f the emitter was maintained by controlled injection of air into the system. The effect of various gases and vapours other than air was also studied. All ion current measurements were at pressures of 1.5 × 10 -s to 2 × 10 -5 torr but the conclusions may be applied to the whole range of operating pressures of the halide leak detector. The results show that the amplification of the ion current by the halogens is dependent on the presence of alkali metal ions. It is suggested that the halogen ions modify the properties of the incandescent platinum surface towards the neutral alkali atoms which arrive there, originating from the ceramic pipe. The supply of alkali metal ions is soon exhausted and the efficiency of the leak detector is reduced. To remedy this it is recommended that, in the preparations of the emitter, the ceramic is immersed in boiling aqueous alkaline solution and subsequently annealed in air for a few hours. V I Karpov et al, Zh Tekh Fiz, 35 (9), 1663, (in Russian).
3O 270. Ion beam depesition--microelectronic applications. (USA) Demonstration of the feasibility of depositing resistive and conductive patterns on dielectric substrates. A R Wolter, Microelectronics and Rehabihty, 4, 1965, 101-102. 30 271. A CdSe-ZnSe thin film rectifier. (USA) Description of the propert,es of a thin-film rectifier formed on a glass substrate by vacuum-deposition of a graded CdSe-ZnSe film between two deposited gold electrodes. W A Gutierrez and H L Wilson, IEEEProc, 53, 1965, 749.
30 272. Poly-para-xylylene in thin film applications. (USA) The thin films are deposited using an unusual vacuum process m which the crystalline solid is sublimed under vacuum and then pyrolyzed to give a nearly quantitative yield of the reactive intermediate, p-xylylene. F E Carion et al, IEEE Trans on Parts, Materials andPackaging, vo[
PMP-1, 1965, 54-62. 30 : 42
273. Glass coating by vacuum deposition. (USA) Description of processes and applicattons. E M Wiiliamson Jr, Glass lnd, 46 (5), 1965, 262-264.
3O 274. Relation of the epitaxy temperature to the parameters of vacuum deposition. ( USSR) Theoretical considerations are given confirming existing experimental data. S P Svetlov, Kristallografia, 10 (4), 1965, 586-588 30 : 39 275. Solid surfaces in vacuum. (Switzerland) The review of some of the properties of solid surfaces includes some results obtained by low-energy electron diffraction. W Eppreeht, Sehwelz Arch dngew Wiss Tech, 31 (2), 1965, 33-39 30 276. The problem of silicon evaporation in producing epitaxial films.
(USSR) 29. Heating~quipment and thermometers 28 267. Thermocbuple for measuring high temperatures in vacuum and helium. ( USSR) G E Pletenetskii, Zavodsk Lab, 30 (5), 1964, 625-628.
29. Miscellaneous 29 : 37 268. A vacuum lock for the direct insertion of samples into a mass spectrometer. (USA) Commercially available vacuum locks are generally expensive, bulky, require venting for sample changes and lack flexibility in application and operation. A direct insertion vacuum lock which eliminates all these disadvantages is described. It is easily fabricated from a commercial gate valve by modification of the removable end caps. This process is described and illustrated. This device has given completely trouble-free daily operation for the past two years on the General Electric mass spectrometer. In this case, the ultimate
Films obtained from silicon evaporated in crucibles under vacuum are contaminated due to the chemical reactivity of liquid silicon. In the method described contamination was eliminated by use of a melted zone of silicon, held between silicon rod electrodes, by surface tension, as an evaporating source. Silicon was deposited on a p-type single crystal silicon substrate cut parallel to the 111 plane and having a resistivity of 69 ohm/cm. The substrate was heated in 3 0 m i n u t e s t o l 0 0 0 O C u n d e r a v a c u u m o f 2 x I 0 - 6 t o 3 × 10-~torr, using a tantalum heater Single crystal, p-type films, 3 to 4 p thick were obtained with substrate temperatures of 950 to 1100°C. The films showed a resistivity of 0.3 to 0.4 ohm/cm and room temperature Hall mobility of 120 to 130 cm~/sec. Successive stages of epitaxial growth were observed and the triangular shapes appearing in the growth figures Indicate a condensation mechanism o f the vapour --> crystal type. The method has the advantage of simplicity in addition to resolving the film contamination problem. A I Petrin and G A Kurov, Crystallography, 10 (5), 1965, 754, (in
Russian). 107