- Email: [email protected]
Semiconducting thin layers which exhibit a high mobility
232
A B S T R A C T S ON M I C R O E L E C T R O N I C S AND R E L I A B I L I T Y
equipment programmed with respect to the pumping and coating cycle is described. A typical processing cycle is described for producing the passive elements of a binary circuit. In conclusion possible developments in both vacuum apparatus and preparation techniques are considered. Deposition and m o n i t o r i n g apparatus for preparing passive m i c r o c i r c u i t s . Part 4. W. STECKELMACHER, J. ENGLISH, H. H. A. BATH, D. HAYNES, J. T. HOLDEN and L. HOLLAND.Electron. Components, August, 675 (1964). The electrical properties of film materials suitable for use as passive elements in microminiature circuits are reviewed together with methods of" monitoring film thickness. The design and performance of a direct-reading quartz crystal monitor for controlling dielectric film thickness is described. The control of resistance films by" a separate monitor used with an electromagnetically operated source shutter is also discussed. Two basic methods of preparing passive microcircuits using metal evaporation masks are considered. The first uses a sequential mask system and substrate magazine producing microcircuits within a single vacuum chamber. The second used fixed masks arranged on a rotary plane holder for preparing individual elements in a batch process. Suitable vacuum deposition equipment programmed with respect to tile pumping and coating cycle is described. A typical processing cycle is described for producing the passive elements of a binary circuit. In conclusion possible developments in both vacuum apparatus and preparation techniques are considered. Thin film e l e c t r o n i c s in the U.S.A. Part 3. G. SIDD?,LL. Electron. Components, May, 413 (1964). Covers work on quartz crystals, solar cells, magnetic films, tilin film diodes, thin film triodes, cryogenic superconducting films, and photoconductive and electro[uminescent films. Thin film e l e c t r o n i c s in the U.S.A. Part 4. G. StDOALL. Electron. Components, August, 670 (1964). During the past four or five years, the use of thin films in electronics has increased very rapidly in America. This has been due almost entirely to the extensive military programme of" space research and missile development, and as a result of this programme contracts worth many millions of dollars have been awarded to research and development teams working in industry, in Research Institutes and in Universities. Progress in this field is so rapid, and individual projects have been duplicated so many" times, that a complete review of tile subject would be ahnost impossible. The number of published reports concerning thin film and related vacuum techniques now exceeds two thousand, and this represents only a part of the total effort, some of which remains unpublished for security reasons. Before initiating a programme of thin fihn research in the Electronics Department at the Electrical Research Association, it was considered essential to visit the USA and obtain some first-hand knowledge of research and development work in a reasonable cross-section of industrial laboratories and research institutions. Altogether, visits were made to twenty establishments. Scratch test for m e a s u r i n g a d h e r e n c e of thin films to oxide substrates. M. M. KAm',rOWSKY and W. B. ESTILL. Re~'. Sci. Instrum. 35, 1324 (1964). The adherence of films on oxide substrates is measured by a scratch-test technique using a commercially available hardness tester. Test results viewed by transmitted light on transparent substrates show: (1) how contamination can cause failure of potentially'adherent film; and (2) how a potential adherence (on a well-cleaned substrate) is related to the free energy of formation of the metal oxide. S e m i c o n d u c t i n g thin layers w h i c h exhibit a high mobility. M. *IAP~IS and A. PERIG.'~UD.L'Onde Electrique, October, 1005 (1964) (French). The authors investigate on the possibility of obtaining semiconducting thin layers which exhibit a lligh mobility suitable for the manufacture of a non-destructive reading device of a computer memory. After a review of the various processes of preparing thin layers, the evaporation method called "three temperatures method" is being chosen as suitable for the preparation of I I I - V semiconductors. The apparatus and precautionary" measures to be taken with a view to obtaining high mobility values are described in detail. To conclude, results of measurements which were made, are provided. Values yielded approximately those that may be obtained on solid material. Structure of thin layers of m a g n e s i u m fluoride: theoretical interpretation of their formation. M. BOURGand A. BOURG. Vacuum, 14, 253 (1964). Thin layers of magnesium fluoride were studied by, electron diffraction and the structure found confirms the results obtained by optical methods. The theory of adsorption was applied to the process of formation of the layers and the existence of chemical bonds between the layer and the support was shown.
A B S T R A C T S ON M I C R O E L E C T R O N I C S AND R E L I A B I L I T Y
equipment programmed with respect to the pumping and coating cycle is described. A typical processing cycle is described for producing the passive elements of a binary circuit. In conclusion possible developments in both vacuum apparatus and preparation techniques are considered. Deposition and m o n i t o r i n g apparatus for preparing passive m i c r o c i r c u i t s . Part 4. W. STECKELMACHER, J. ENGLISH, H. H. A. BATH, D. HAYNES, J. T. HOLDEN and L. HOLLAND.Electron. Components, August, 675 (1964). The electrical properties of film materials suitable for use as passive elements in microminiature circuits are reviewed together with methods of" monitoring film thickness. The design and performance of a direct-reading quartz crystal monitor for controlling dielectric film thickness is described. The control of resistance films by" a separate monitor used with an electromagnetically operated source shutter is also discussed. Two basic methods of preparing passive microcircuits using metal evaporation masks are considered. The first uses a sequential mask system and substrate magazine producing microcircuits within a single vacuum chamber. The second used fixed masks arranged on a rotary plane holder for preparing individual elements in a batch process. Suitable vacuum deposition equipment programmed with respect to tile pumping and coating cycle is described. A typical processing cycle is described for producing the passive elements of a binary circuit. In conclusion possible developments in both vacuum apparatus and preparation techniques are considered. Thin film e l e c t r o n i c s in the U.S.A. Part 3. G. SIDD?,LL. Electron. Components, May, 413 (1964). Covers work on quartz crystals, solar cells, magnetic films, tilin film diodes, thin film triodes, cryogenic superconducting films, and photoconductive and electro[uminescent films. Thin film e l e c t r o n i c s in the U.S.A. Part 4. G. StDOALL. Electron. Components, August, 670 (1964). During the past four or five years, the use of thin films in electronics has increased very rapidly in America. This has been due almost entirely to the extensive military programme of" space research and missile development, and as a result of this programme contracts worth many millions of dollars have been awarded to research and development teams working in industry, in Research Institutes and in Universities. Progress in this field is so rapid, and individual projects have been duplicated so many" times, that a complete review of tile subject would be ahnost impossible. The number of published reports concerning thin film and related vacuum techniques now exceeds two thousand, and this represents only a part of the total effort, some of which remains unpublished for security reasons. Before initiating a programme of thin fihn research in the Electronics Department at the Electrical Research Association, it was considered essential to visit the USA and obtain some first-hand knowledge of research and development work in a reasonable cross-section of industrial laboratories and research institutions. Altogether, visits were made to twenty establishments. Scratch test for m e a s u r i n g a d h e r e n c e of thin films to oxide substrates. M. M. KAm',rOWSKY and W. B. ESTILL. Re~'. Sci. Instrum. 35, 1324 (1964). The adherence of films on oxide substrates is measured by a scratch-test technique using a commercially available hardness tester. Test results viewed by transmitted light on transparent substrates show: (1) how contamination can cause failure of potentially'adherent film; and (2) how a potential adherence (on a well-cleaned substrate) is related to the free energy of formation of the metal oxide. S e m i c o n d u c t i n g thin layers w h i c h exhibit a high mobility. M. *IAP~IS and A. PERIG.'~UD.L'Onde Electrique, October, 1005 (1964) (French). The authors investigate on the possibility of obtaining semiconducting thin layers which exhibit a lligh mobility suitable for the manufacture of a non-destructive reading device of a computer memory. After a review of the various processes of preparing thin layers, the evaporation method called "three temperatures method" is being chosen as suitable for the preparation of I I I - V semiconductors. The apparatus and precautionary" measures to be taken with a view to obtaining high mobility values are described in detail. To conclude, results of measurements which were made, are provided. Values yielded approximately those that may be obtained on solid material. Structure of thin layers of m a g n e s i u m fluoride: theoretical interpretation of their formation. M. BOURGand A. BOURG. Vacuum, 14, 253 (1964). Thin layers of magnesium fluoride were studied by, electron diffraction and the structure found confirms the results obtained by optical methods. The theory of adsorption was applied to the process of formation of the layers and the existence of chemical bonds between the layer and the support was shown.