RESEARCH INVESTIGATIONS IN THE PHYSICAL CHEMISTRY AND METALLURGY OF SEMICONDUCTING MATERIALS Third Quarterly Report

摘要

The following are considered to be significant factors in crystal growth:n(1) Slow growth rates tend to increase the tendency to -n(a) monocrystalline structure,n(b) increase surface damage (due to longer periods in ambient at high temperature)n(2). Fast growth rates result in very much smoother skin surface but poorer crystalline structure throughout the crystal.n(3). The starting boron must be of high purity,n(4). The volume of the melt should be as large as possible and the volume of the melt should be maintained at a constant value during the crystal growth.n(5). When the boron starting material is a crystalline boron bar (as deposited from the vapor phase), the bar should be free of dendrites on the surface. In fact, it is preferred to first densify this crystalline bar by zone melting, or at least zone melting the surface to free it of dendrites.n(6). The crystalline deposit which is always molten at the upper end during the crucible-free Czochralski crystal growth should have an appreciably larger diameter than the crystal which is grown from it.