Electron-beam evaporated silicon films for MIS photovoltaics: Properties of films and devices

The feasibility of extending MIS (metal insulator semi-conductor) photovoltaic technology to vacuum deposited, thin film polycrystalline silicon is demonstrated. Rectifying MIS junctions, exhibiting strong photovoltaic response, are formed on high purity, boron doped silicon films produced by electron beam evaporation. The physical and electrical properties of the films are investigated, and device properties analyzed. The dissolution of Si by the Al layer, and the subsequent formation of Si growth centers at the surface of the Al layer, is extensively documented by scanning electron microscopy studies. A model is proposed relating the surface density of growth centers to the initial Si incidence rate. The relation of the growth centers to the observed columnar growth is discussed.