Low temperature, defect-free silicon epitaxy using a low kinetic energy particle process

Abstract

Concurrent bombardment of a growing film surface by Ar ions having low kinetic energies comparable to typical inter-atomic binding energies has been utilized to activate the film surface. It has been shown that such activation is quite effective and can be substituted for substrate heating during crystal growth. As a result, high quality, device grade epitaxial silicon films have been successfully grown at very low temperatures of 250°–300° C. In this epitaxial growth process, dopant impurities in the target are fully incorporated into the grown film and 100% electrically activated at such low temperatures. The direction for further reducing the epitaxial silicon growth temperature has been examined experimentally, and it is shown that the establishment of anultra clean processing environment andultra clean wafer surface as well asperfect process parameter control are quite essential for very low temperature silicon epitaxy.