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Ion implantation for silicon device fabrication
WORLD
ABSTRACTS
ON MICROELECTRONICS
that the stopping power of SiOs is reduced as has been proposed elsewhere. Further, it has been predicted that gate control will be lost for depletion mode transistors with sufficiently deep implants. This is caused by the formation of a deep channel which is isolated from gate control by an induced surface charge layer. The inability of the gate field to pinch off the channel defeats device use for transistor inverter loads.
Ion implantation for silicon device fabrication. V. G. K. RF~DI and A. Y. C. Yu. ,Solid ,St. Technol., October (1972), p. 35. Processing and design guidelines in the utilization of ion implantation for silicon device fabrication are presented. These include proper wafer tilting during implantation and post implantation heat treatments necessary to anneal the implantation damage. Spatial distribution of implanted impurities such as arsenic, boron and phosphorus as a function energy are shown. Experimental results obtained with the double implanted npn transistors are discussed.
Ionen-Mikrosonden-Analysatoren. H. LIEBL. (In German.) Messtechnik 12/72. p. 358. The ion microprobe analyzer is an apparatus for analysis of solid surfaces with high spatial resolution. An energetic primary ion beam is focused to a fine probe of about 1 gm diameter on the sample surface. By means of a deflection system the surface can be scanned, or a certain spot in the field of view can be bombarded. Out
AND
RELIABILITY
217
of the sputtered particles the secondary ions are accelerated into a mass spectrometer with high transmission and mass analyzed. By tuning the mass spectrometer to a certain mass and using the output to modulate the brightness of an oscilloscope the X - and I1- deflection of which is synchronized with the primary beam deflection, semiquantitative pictures showing the distribution of that certain element over the field of view are obtained. On the other hand, by directing the probe to a certain spot and making a mass scan, a mass analysis of that spot can be obtained. The method is distinguished by high sensitivity.
Electrical contacts to ion cleaned n-type gallium arsenide. G. H. WALKER and E. J. CONWAY. I E E E Trans. Parts, Hybrids Packng PHP-8, No. 4, December (1972), p. 49. The electrical current through silver contacts evaporated on to n-type gallium arsenide as a function of surface treatment is reported. Contacts to untreated gallium arsenide exhibit the expected high resistance. Surface cleaning by argon ion bombardment reduces the resistance by three orders of magnitude. T h e electrical resistance beyond 850 eV increases rapidly with ion bombardment energy. T h e resistance minim u m at 850 eV is explained semiquantitatively in terms of a balance between cleaning and surface damage. This type of contact is appropriate for addition to a finished material whose properties are to be investigated, but may not be adequately ohmic for use on production devices.
ABSTRACTS
ON MICROELECTRONICS
that the stopping power of SiOs is reduced as has been proposed elsewhere. Further, it has been predicted that gate control will be lost for depletion mode transistors with sufficiently deep implants. This is caused by the formation of a deep channel which is isolated from gate control by an induced surface charge layer. The inability of the gate field to pinch off the channel defeats device use for transistor inverter loads.
Ion implantation for silicon device fabrication. V. G. K. RF~DI and A. Y. C. Yu. ,Solid ,St. Technol., October (1972), p. 35. Processing and design guidelines in the utilization of ion implantation for silicon device fabrication are presented. These include proper wafer tilting during implantation and post implantation heat treatments necessary to anneal the implantation damage. Spatial distribution of implanted impurities such as arsenic, boron and phosphorus as a function energy are shown. Experimental results obtained with the double implanted npn transistors are discussed.
Ionen-Mikrosonden-Analysatoren. H. LIEBL. (In German.) Messtechnik 12/72. p. 358. The ion microprobe analyzer is an apparatus for analysis of solid surfaces with high spatial resolution. An energetic primary ion beam is focused to a fine probe of about 1 gm diameter on the sample surface. By means of a deflection system the surface can be scanned, or a certain spot in the field of view can be bombarded. Out
AND
RELIABILITY
217
of the sputtered particles the secondary ions are accelerated into a mass spectrometer with high transmission and mass analyzed. By tuning the mass spectrometer to a certain mass and using the output to modulate the brightness of an oscilloscope the X - and I1- deflection of which is synchronized with the primary beam deflection, semiquantitative pictures showing the distribution of that certain element over the field of view are obtained. On the other hand, by directing the probe to a certain spot and making a mass scan, a mass analysis of that spot can be obtained. The method is distinguished by high sensitivity.
Electrical contacts to ion cleaned n-type gallium arsenide. G. H. WALKER and E. J. CONWAY. I E E E Trans. Parts, Hybrids Packng PHP-8, No. 4, December (1972), p. 49. The electrical current through silver contacts evaporated on to n-type gallium arsenide as a function of surface treatment is reported. Contacts to untreated gallium arsenide exhibit the expected high resistance. Surface cleaning by argon ion bombardment reduces the resistance by three orders of magnitude. T h e electrical resistance beyond 850 eV increases rapidly with ion bombardment energy. T h e resistance minim u m at 850 eV is explained semiquantitatively in terms of a balance between cleaning and surface damage. This type of contact is appropriate for addition to a finished material whose properties are to be investigated, but may not be adequately ohmic for use on production devices.