Ionized cluster beam deposition of sapphire and silicon layers

摘要

Sapphire, a highly stable oxide of aluminum having the chemical formula of Al.sub.2 O.sub.3, is placed in a crucible. The crucible is heated to vaporize the sapphire therein. The sapphire vapor is ejected through a nozzle in the crucible and into a region having a vacuum pressure of approximately 10.sup.-5 Torr or less. As the vapor leaves the crucible through the nozzle, atom aggregates or clusters are formed through a supercooled phenomenon due to adiabatic expansion. The vacuum region has disposed therein a substrate of silicon. The sapphire vapor is accelerated towards the substrate where it deposits on a surface of the substrate in a uniformly distributed thin layer.