Simulation of bandgap narrowing and incomplete ionization in strained Si 1− xGe x alloys on 〈001〉 Si substrate (for temperatures from 40 K up to 400 K)

Abstract

The modelling of bandgap narrowing and partly ionized impurity atoms in uncompensated, uniformly doped coherently strained Si 1− x Ge x alloys on a 〈001〉 Si substrate [containing conventional impurities (B, P, As, Sb)] under charge-neutral conditions is presented. The above is a generalization of previous work of the authors for Si [Mamontov and Willander, IEICE Trans. Electron. E77-C, 287 (1994)] [13]. The present approach is valid for concentrations up to the electrically-active-impurity-concentration limits and for a temperature range from 40 up to 400 K. The calculation results are discussed. A good agreement with numerical data extracted from measurement results is noted. The present modelling and software can be used in research and design of charge-neutral regions of Si HBTs with a Si 1− x Ge x base and heterojunction photoemission infrared detectors for application at cryogenic operating temperatures.