THE CHEMISTRY OF THE GROWTH OF ZNS DEPOSITED BY RF-SPUTTERING ONTO CADMIUM STANNATE .1. THE INTERFACE

The initial growth of ZnS thin films deposited by r.f. sputtering onto cadmium stannate substrates has been traced, showing how a chemical interface approximately 100 Å wide is developed. Although graded in composition across this width, the interface develops uniformly. When ZnS layers 0.5-1.0 microm thick are profiled using techniques such as Auger electron spectroscopy and secondary-ion mass spectroscopy, the interface appears to be much broader. The broadening effect is largely a consequence of the surface topography of the sample and results in loss of detail in the immediate vicinity of the true interface. The ZnScadmium stannate junction is chemically active; post-deposition annealing causes further interdiffusion, cadmium being the most mobile element. Variations in the extent of cadmium diffusion were found in nominally identical samples. © 1990.