Liquid phase epitaxy (LPE) of (Hg,Cd)Te (MCT) is the technique of choice for the preparation of the materials used for high performance focal plane arrays. Its successful development requires the development of advanced sensors and process controls. We detail here progress on the application of four sensor technologies to the LPE process for growth of MCT layers from Te rich melts on CdZnTe substrates. These include: (1) electron beam microprobe/wavelength dispersive x-ray analysis (WDX) for the rapid measurement of film composition immediately after growth; (2) an RTD based precision temperature control system that controls the melt temperature to better than +/- 0.005 degree(s)C and the Hg reservoir temperature to better than +/- 0.020 degree(s)C; (3) UV/visible optical absorption spectroscopy for the determination of the Hg partial pressure over the melt; and (4) CCD imaging for the detection of the liquid temperature of the LPE growth solution. The impact of each of the sensors on process yield is discussed. The application of the CCD camera to Hg rich high pressure LPE growth is also briefly mentioned.

Date Published: 13 July 1994
PDF: 20 pages
Proc. SPIE 2228, Producibility of II-VI Materials and Devices, (13 July 1994); doi: 10.1117/12.179679

Published in SPIE Proceedings Vol. 2228:
Producibility of II-VI Materials and Devices
Herbert K. Pollehn; Raymond S. Balcerak, Editor(s)