Formation of doped polycrystal si layers through solid phase pegrowth

Abstract

n-type polycrystal Si films have been grown by implantation with P + ions into amorphous Si films deposited on thermal SiO 2, followed by thermal annealing. High electrical activation of the implanted P atoms and high carrier mobility are obtained in the polycrystal Si film grown by low temperature annealing, e.g., at 600 ° C. These results can be explained by the fact that a polycrystal Si film with large grains is grown by low temperature annealing as revealed by TEM observation. Uniformly distributed carrier profiles are built into the polycrystal Si films grown by high temperature annealing, e.g., at 1000°C. From these results, a two-step-annealing, low temperature annealing followed by high temperature annealing, is proposed as an important process by means of which polycrystal Si films can be grown with desirable properties such as high carrier concentrations, high carrier mobilities, and a uniformly distributed carrier profile.