Light-Induced Plasticity in Semiconductors

Abstract

It has been found that light of wavelength between 2.0 and 4.0 μ, or shorter than 0.4 μ, 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.