Light-Induced Plasticity in Semiconductors

Abstract

It has been found that light of wavelength between 2.0 and 4.0 \ensuremath{\mu}, or shorter than 0.4 \ensuremath{\mu}, decreases the hardness of the surface layer of $n$-type germanium by 10 to 60%. The softened layer extends to a depth of one to two microns. A similar but less intense effect was observed in $p$-type germanium and $n$-type InSb and InAs. On the other hand, $p$-type silicon seems to soften to a greater extent than germanium. The effect is proportional to light intensity and is affected by surface preparation.