Relevance of Thermal Mismatch in Large-Area Composite Substrates for HgCdTe Heteroepitaxy

It is well known that the large lattice mismatch (>14%) associated with CdTe/Si, CdTe/Ge, and CdTe/GaAs composite substrates, is a great contributor to large dislocation densities and other defects that limit the performance of HgCdTe-based infrared detectors. Though thermal expansion mismatch is...

Full description

Saved in:
Bibliographic Details
Published in:Journal of electronic materials 2008-09, Vol.37 (9), p.1480-1487
Main Authors: Jacobs, R.N., Almeida, L.A., Markunas, J., Pellegrino, J., Groenert, M., Jaime-Vasquez, M., Mahadik, N., Andrews, C., Qadri, S.B., Lee, T., Kim, M.
Format: Article
Language:English
Subjects:
Applied sciences
Characterization and Evaluation of Materials
Chemistry and Materials Science
Composition and phase identification
Condensed matter: structure, mechanical and thermal properties
Crystal lattices
Electronics
Electronics and Microelectronics
Exact sciences and technology
Gallium arsenide
Instrumentation
Instruments for strain, force and torque
Instruments, apparatus, components and techniques common to several branches of physics and astronomy
Materials Science
Mechanical instruments, equipment and techniques
Mercury cadmium telluride
Optical and Electronic Materials
Optoelectronic devices
Physical properties of thin films, nonelectronic
Physics
Residual stress
Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices
Semiconductors
Solid State Physics
Surfaces and interfaces
thin films and whiskers (structure and nonelectronic properties)
Thermal stability
thermal effects
Thin film structure and morphology
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:It is well known that the large lattice mismatch (>14%) associated with CdTe/Si, CdTe/Ge, and CdTe/GaAs composite substrates, is a great contributor to large dislocation densities and other defects that limit the performance of HgCdTe-based infrared detectors. Though thermal expansion mismatch is another possible contributor to material defects, little work has been done towards documenting and understanding its effects in these systems. Here, we perform studies to determine the relative contributions of lattice and thermal mismatch to CdTe film characteristics, including dislocation density and residual stress. Unannealed and thermally cycled films are characterized using x-ray diffraction, defect decoration, and Nomarski and transmission electron microscopy. For CdTe/Si, the residual stress is consistently observed to be tensile, while for CdTe/Ge and CdTe/GaAs, a compressive residual film stress is measured. We show based on theoretically predicted stress levels that the experimental measurements imply the dominance of thermal mismatch in the residual stress characteristics.
ISSN:0361-5235
1543-186X
DOI:10.1007/s11664-008-0519-z