Local surface potential on hydrogenated microcrystalline silicon films

Abstract

The local surface potential on hydrogenated microcrystalline silicon films was investigated using a Kelvin force microscope. In the surface morphology image of the films deposited on Asahi U-type substrates, large and small convex grains were observed. In i-type films, the surface potentials on the large and small convex grains were higher than those in the concave regions between large convex grains and between small convex grains, respectively. The potential difference between a large grain and the region between large grains was larger than that between a small grain and the region between small grains. The surface potential distribution on p-type films showed the same tendency as that on the i-type films. On the other hand, the surface potential distribution on n-type films showed a reverse tendency to that on the i-type films. The potential difference between a large convex grain and the region between large convex grains depended on the doping ratio and that in the p-type films was smaller than that in the n-type films.