COMPLETE INSITU LASER MONITORING OF MOCVD HGCDTE CDTE ZNTE GROWTH ONTO GAAS SUBSTRATES

Specular HeNe laser reflectance has been used as a continuous in situ monitor of growth rate, thickness and composition during the growth of multilayer films of Hg1-xCdxTe(MCT)/CdTe/ZnTe onto GaAs (100)10-degrees-->(110) substrates. Accurate in situ monitoring has enabled thickness measurement of the thin ZnTe nucleation layer which has been shown to critically influence the X-ray rocking curve widths in the CdTe buffer layer. Monitoring of the alternate layers of HgTe and CdTe in the interdiffused multilayer process (IMP) has identified growth rate instabilities and subsequent improvement in uniformity. This, the first complete in situ monitoring of mercury cadmium telluride (MCT) metalorganic chemical vapor deposition (MOCVD) growth, has resulted in new insights into the growth process.