Real Time Monitor and Control of MBE Growth of HgCdTe by Spectroscopic Ellipsometry.
Abstract
The primary goal of this contract develop a real-time monitoring capability for HgCdTe composition during MBE growth. This goal was realized by demonstrating a + or - 0.001 accuracy in the composition values determined by the Spectroscopic Ellipsometry (SE) in situ sensor, which was confirmed by exsitu FTIR measurements. Attaining this level of success required significant improvements in the ellipsometer system hardware and data analysis software, the creation of accurate optical constant libraries for the CdZnTe Substrate and HgCdTe film materials, and the development of a systematic methodology for acquiring and analyzing insitu SE data in the MBE growth environment. These improvements and developments are part of an extensive 'knowledge base' which evolved throughout this contract, and is encapsulated in this report. This knowledge base is not specific only to HgCdTe growth; it is also directly relevant to the insitu SE monitoring of any epitaxial semiconductor growth process. In addition to the HgCdTe composition monitoring capabilities, insitu SE was also found to be very useful in monitoring the temperature and the surface condition of the CdZnTe substrate before growth, surface roughening during the initiation of HgCdTe growth, and the surface morphology during ECR etching of HgCdTe films.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 08, 1996
- Accession Number
- ADA317784
Entities
People
- Blaine Johs