Development of HgCdSe for Third Generation Focal Plane Arrays using Molecular Beam Epitaxy
Abstract
Hg(1-x)Cd(x)Se grown on nearly lattice-matched GaSb substrates could serve as a new basis for infrared detector development. The preparation of the GaSb substrate surfaces and the growth of ZnTe(1-x)Se(x) buffer layers via molecular beam epitaxy were investigated. ZnTe and ZnTe1-xSex layers were grown on GaSb substrates prepared with atomic hydrogen cleaning. The lattice constant of ZnTe(1-x)Se(x) was tuned by controlling the ratio of Se/Te beam equivalent pressures, and ZnTe(1-x)Se(x) was found to be lattice-matched to GaSb for x=0.01. Confocal photoluminescence measurements indicated that ZnTe(0.99)Se(0.01) layers grown on GaSb have dislocation densities roughly 7x10(^4) cm(^-2), indicating that ZnTe(0.99)Se(0.01) /GaSb provides a high quality substrate with low dislocation densities for Hg(1-x)Cd(x)Se growth. In parallel with the ZnTe(1-x)Se(x)/GaSb substrate development, the growth of Hg(1-x)Cd(x)Se was studied via molecular beam epitaxy on GaSb substrates and Si substrates with ZnTe buffer layers. Growth rate, composition, and surface quality were evaluated for different growth parameters. Previous studies of nominally undoped Hg(1-x)Cd(x)Se samples have reported large background electron concentrations. In the study reported here, the use of Se source material with 6N purity instead of 5N reduced the electron concentration, suggesting contaminants in the Se source material are a significant source of the background electrons.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 2013
- Accession Number
- AD1019656
Entities
People
- Kevin Doyle
Organizations
- Texas State University