Etch pit characterization of CdTe and CdZnTe substrates for use in mercury cadmium telluride epitaxy
A new etch system is described which produces pits on the technologically important B face of (111) and (211) CdTe and CdZnTe which are commonly used in mercury cadmium telluride (MCT) epitaxy. A ratio of approximately 10 wide: 1 deep is achieved with this etch allowing its use without removing excessive material. Examples of the use of this etch are given and a comparison is made with the Nakagawa, A face etch system which is in common use to characterize this family of materials. A screening protocol is discussed which integrates the use of etch pitting into the manufacture of substrates for use in epitaxial MCT applications. Comparisons are made between CdZnTe substrates grown using the horizontal and vertical Bridgman techniques.