Germanium content dependence of radiation damage in strained Si/sub 1-x/Ge/sub x/ epitaxial devices

Abstract

The irradiation damage in n/sup +/-Si/p/sup +/-Si/sub 1-x/Ge/sub x/ epitaxial diodes and n/sup +/-Si/p/sup +/-Si/sub 1-x/Ge/sub x//n-Si epitaxial heterojunction bipolar transistors (HBTs) by fast neutrons and MeV electrons is studied as a function of fluence and germanium content for the first time. The degradation of the electrical performance of both diodes and HBTs by irradiation increases with increasing fluence, while it decreases with increasing germanium content. The damage coefficient of reverse current for x=0.12 and 0.16 diodes irradiated by neutrons is calculated to be 6.2/spl times/10/sup -21/ and 5.5/spl times/10/sup -21/ n/sup -1/ A cm/sup 2/, respectively. That of h/sub FE/ for electron-irradiated x=0.08, 0.12 and 0.16 HBTs is 7.6/spl times/10/sup -16/, 2.7/spl times/10/sup -16/ and 1.6/spl times/10/sup -16/ s/sup -1/ cm/sup 2/ respectively.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>