CdZnTe Substrate Screening

HgCdTe is used throughout the U.S. Department of Defense for producing highly sensitive infrared Focal Plane Arrays (FPAs). FPAs containing millions of pixels as small as 10-20 micrometers are used to image high resolution very large scenes.  The cost of producing these large FPAs, however, are prohibitively high for some applications. One of the major reasons for this high cost is both the cost and quality of the CdZnTe substrates used to grow the HgCdTe film on. A number of these substrates are suspected of containing extended defects which lead to failing HgCdTe films grown on them epitaxially.  To address this issue, a non-destructive (NDE) technique is proposed base on optical technologies that enables inspection of substrates with high sensitivity, enabling rapid screening of the entire substrates for defects.  To demonstrate the effectiveness of the proposed NDE technique for detection and eventual yield increase, tests will be performed during Phase I to identify defects in CdZnTe substrates and correlate them to defects in HgCdTe films