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Title: Formation of defects in Si and Ge under radiation-accelerated diffusion conditions

Journal Article · · Sov. Phys. - Semicond. (Engl. Transl.); (United States)
OSTI ID:6228189

An investigation was carried out with the main purpose of determining by electron-microscopic methods the properties of the secondary radiation defects that appear under radiation-accelerated diffusion conditions in Si and Ge. The main types of defect in Si irradiated at T/sub i/rr =400--600/sup 0/C and in Ge irradiated at 400/sup 0/C were rod-shaped and oriented along <110> axes. An electron-microscopic examination showed that these defects were interstitial and were essentially narrow platelets with the )113) habit. The rod-shaped defects should be regarded as precipitates containing not only interstitial matrix atoms but also impurity atoms (most probably oxygen and carbon). The high diffusion mobility of interstitial atoms was responsible for the formation of the rod-shaped defects in a surface layer of an Si crystal up to approx.5 ..mu.. thick, which was considerably greater than the depth of penetration (range) of protons R/sub p/approx.2.5 ..mu... Increase of the irradiation temperature and dose tended to transform the rod-shaped defects into complete dislocation loops. An active interaction took place between dislocation loops and vacancies in Si irradiated at T/sub i/rr> or approx. =600/sup 0/C, which reduced strongly the density of the rod-shaped defects and dislocation loops in the irradiated crystals. High-temperature irradiation (T/sub i/rr=400--800/sup 0/C) with H/sup +//sub 2/ ions of 500 keV energy resulted in radiation-accelerated diffusion of boron which was implanted in Si. A correlation was found between the presence of the rod-shaped defects and deterioration of the properties of p-n junctions formed by radiation-accelerated diffusion. The presence of these defects resulted in the leakage of carriers across the p-n junctions.

Research Organization:
Institute of Semiconductor Physics, Siberian Branch of the Academy of Sciences of the USSR, Novosibirsk
OSTI ID:
6228189
Journal Information:
Sov. Phys. - Semicond. (Engl. Transl.); (United States), Vol. 13:1
Country of Publication:
United States
Language:
English