GROWTH OF EPITAXIAL GEXSI1-X FOR INFRARED DETECTORS BY UHV/CVD

摘要

We report the application of UHV/CVD (ultra-high vacuum chemical vapor deposition) to the growth of heterojunction infernal photoemission (HIP) infrared detector structures. The HIP structure is essentially a Schottky barrier junction formed between a degenerately doped germanium-silicon absorbing layer and an undoped or lightly doped silicon layer. This device places stringent demands on the background doping concentration and morphology of the epitaxial layers. C(V) profiling shows that acceptably low doping of the silicon layer is obtained only after a cleanup run. Surface morphology of the GexSi1-x absorbing layer is degraded by the formation of thickness undulations, especially at the large boron concentrations required. By appropriate changes to the growth procedure, we have been able to fabricate working detectors with good electrical characteristics. [References: 21]