Molecular beam epitaxial growth of InSb/CdTe and PbTe/CdTe heterosystems using high-quality CdTe(100) films on GaAs (100) substrates

摘要

Molecular beam epitaxial growth of high quality CdTe films on GaAs(1OO) substrates and its application to InSb/CdTe and PbTe/CdTe are described. The target of this work is to develop novel heterojunctions applicable for mid - infrared optical devices that are integrated monolithically on GaAs(100) substrates with electrical circuitry. High - quality CdTe growth on GaAs substrates is the essential technology for this purpose. However, CdTe films on GaAs have been known to include misoriented domains and structural defects due to the presence of large lattice mismatch. It is shown in this report that the use of a sulfur - treated GaAs substrate is effective in eliminating the misorientation, and the crystalline quality of these single - domain CdTe films is further improved by an annealing technique combined with MnTe capping. High - quality CdTe overgrowth at low temperatures is also found probable on the annealed MnTe/CdTe films by using a (CdTe){sub}m(MnTe){sub}n superlattice as a buffer layer. Heterojunctions of InSb/CdTe and PbTe/CdTe are successfully grown on GaAs(100) substrates using high - quality CdTe films.