LARGE-AREA DEPOSITION OF CD1-XZNXTE ON GAAS AND SI SUBSTRATES BY METALORGANIC CHEMICAL-VAPOR-DEPOSITION

Results of large-area (up to 1000 cm(2)/run) Cd1-xZnxTe heteroepitaxy on both GaAs and GaAs/Si substrates by metalorganic chemical vapor dep osition (MOCVD) are presented. Cd1-xZnxTe (x = 0-0.1) films exhibited specular surface morphology, 1% thickness uniformity (standard deviati on), and compositional uniformity (Delta x) of +/-0.002 over 100 mm di am substrates. For selected substrate orientations and deposition cond itions, the only planar defects exhibited by (111)B Cd1-xZnxTe/GaAs/Si films were lamella twins parallel to the CdTe/GaAs interface; these d o not propagate through either the Cd Zn Te layer or subsequently depo sited liquid phase epitaxy (LPE) HgCdTe layer(s). Background Ga and As -impurity levels for Cd1-xZnxTe on GaAs/Si substrates were below the s econdary ion mass spectroscopy detection limit. Preliminary results of HgCdTe liquid phase epitaxy using a Te-rich melt on Si-based substrat es resulted in xray rocking curve linewidths as narrow as 72 are-sec a nd etch-pit densities in the range 1 to 3 x 10(6) cm(2).