INVESTIGATION OF THE SURFACE OF P-IMPLANTED LPCVD SILICON FILMS

The surface morphology and crystallization of amorphous and polycrysta lline silicon films, P-implanted at doses between 2x10(14) and 8x10(15 ) cm(-2) and annealed at 950 degrees C, were investigated by scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques. It i s found that a secondary grain growth process, dependent on the phosph orus dose, occurs al the film surface. Increasing the implantation dos e above 5 x 10(15) cm(-2) determines the retardation of the grain grow th. The mechanisms considered responsible for the structural changes o f the films are the phosphorus diffusion on the grain boundary regions , determining the secondary grain growth, and the phosphorus segregati on at the grain boundary, which determines the retardation process.