METALORGANIC CHEMICAL VAPOR-DEPOSITION OF PBTE FILMS ON GAAS SUBSTRATES

PbTe films on GaAs substrates were grown by metalorganic chemical vapor deposition for the first time, at substrate temperatures as low as 300-degrees-C. Films grown directly on GaAs below a substrate temperature of 400-degrees-C showed (111) orientation on (100) GaAs and (100) orientation on (111) GaAs. However, above 400-degrees-C on GaAs and on CdTe buffer layers, the films followed the orientation of GaAs and CdTe, respectively. Hall measurements showed n-type conductivity in PbTe films grown directly on GaAs regardless of the Te/Pb input gas ratio and substrate temperature. The conductivity type of PbTe films grown on CdTe buffer layers depended on the input gas ratio of Te/Pb. The resistivity measured by Hall measurement was higher than that determined from infrared data, suggesting microcracks in the films.