ROCKWELL INTERNATIONAL ANAHEIM CA MICROELECTRONICS RESEARCH AND DEVELOPMENT C ENTER
This program was designed to study the feasibility of applying the metalorganic chemical vapor deposition technique to the preparation of PbSnTe single-crystal films on suitable substrates, to adjust the composition of the Pbsub 1-xSnsub xTe films for peak response in the 11-12 micrometers wavelength region x approx. 0.2, to fabricate junction-type photovoltaic detectors and detector arrays in the films, and to characterize the resulting detectors to establish the present state of the art of detector material preparation by this technique. Progress toward achieving useful infrared detectors for the 11-12 micrometers region was made in this program. The feasibility of metalorganic CVD processes for the preparation of PbTe, SnTe, and Pbsub 1-xSnsub xTe with x0.1 was demonstrated using tetraethyllead TEPb or tetramethyllead TMPb as the source of Pb, tetraethyltin TESn as the source of Sn, and dimethyltellurium DMTe as the source of Te. It was demonstrated that epitaxial films of PbTe can be grown on Al2O3, MgAl2O4, and BaF2 substrates by this CVD process desired compositons of Pbsub 1-xSnsub xTe alloys can be prepared by controlling the ratio of the reactants and the reaction temperature. Trimethylantimony TMSb was shown to be an effective source of Sb for preparing n-type Pbsub 1-xSnsub xTe films, but the introduction of Sb into the film appears to increase the bandgap slightly. N-type PbTe films were grown by adjusting the ration of Pb and Te concentrations through adjustment of the respective reactant flow rates.