Structural properties of MBE-grown CdTe (133) B buffer layers on GaAs (211) B substrates with CdZnTe/CdTe superlattice-based dislocation filtering layers

Wenwu Pan, Shuo Ma, Xiao Sun, Shimul Kanti Nath, Songqing Zhang, Renjie Gu, Zekai Zhang, Zekai Zhang, Lorenzo Faraone, Wen Lei

Research output: Contribution to journalArticlepeer-review

Abstract

The ever-present demand for high-performance HgCdTe infrared detectors with larger array size and lower cost than currently available technologies based on lattice-matched CdZnTe (211)B substrates has fuelled research into heteroepitaxial growth of HgCdTe and CdTe buffer layers on lattice-mismatched alternative substrates with a (211)B orientation. Driven by the large lattice mismatch, the heteroepitaxial growth of (Hg)CdTe can result in (133)B-orientated material, which, however, has been less explored in comparison to (211)B-oriented growth. Herein, we report on the structural properties of heteroepitaxially grown single-crystal II-VI CdTe (133)B-oriented buffer layers on III-V GaAs (211)B substrates. Azimuthal-dependent x-ray double-crystal rocking curve measurements for the CdTe buffer layers show that the full-width at half-maximum value obtained along the GaAs [ 1 ¯ 11 ] direction is narrower than that obtained along the GaAs [ 01 1 ¯ ] direction, which is presumably related to the in-plane anisotropic structural characteristics of the grown CdTe layers. By incorporating strained CdZnTe/CdTe superlattice-based dislocation filtering layers (DFLs), a significant improvement in material quality has been achieved in (133)B-orientated CdTe buffer layers, including a reduced etch pit density in the low-105 cm−2 range and improved surface roughness. These results indicate that the CdTe (133)B DFL buffer layer process is a feasible approach for growing high-quality CdTe and HgCdTe materials on large-area, low-cost alternative substrates.
Original languageEnglish
Article number185301
JournalJournal of Applied Physics
Volume133
Issue number18
DOIs
Publication statusPublished - 14 May 2023

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