EPITAXIAL GROWTH OF CDS ON IONIC SUBSTRATES

Transmission electron microscopy has been used to study the structure of films of CdS evaporated in vacua in the 10-5 torr range on to (100) cleavage faces and cut and polished (110) and (111) faces of NaCl, and also on to (111) cleavage faces of BaF2, (111) substrate faces were found to produce wurtzite structure (hexagonal) films with great structural perfection over wider ranges of epitaxial growth temperature than (100) substrate faces. The (100) and (110) substrates produced sphalerite structure (cubic) films. Electron beam evaporation and generally clean growth conditions were found to produce good quality films at low substrate temperatures. The films were in general free of any included grains and the diffraction patterns free of satellite spots. 〈111〉 or 〈10-10〉 streaking was present in the diffraction patterns, however, except in the case of films grown on BaF2 above 170° C, and on NaCl (111) above 250° C. These films were also free of planar defects and only contained of the order of 1010 dislocations per cm2. © 1969 Chapman and Hall.