Electrical characterization of Ge microcrystallites by atomic force microscopy using a conducting probe

Abstract

We have studied the nucleation and growth of Ge microcrystallities on Si(100) or evaporated Cr substrates from an rf glow discharge decomposition of GeH 4 highly-diluted with H 2, where the crystallinity, the surface microroughness and the local electric transport of the films have been measured as a function of the film thickness. For the film growth thicker than ∼65 nm, Raman scattering spectra show that the evolution of the microcrystalline phase tends to be saturated. In the thickness range of 7–65 nm, the nucleation and/or microcrystalline grain formation with progressive film growth and corresponding significant difference in the electrical conductivity in the direction of the film thickness between the grains and their boundaries have been demonstrated from topographic and current images taken simultaneously by an atomic force microscope with a conducting probe.