Effects of Phosphorus Pressure on Growth Rate and Layer Quality of InP Grown by Gas Source Molecular Beam Epitaxy

Abstract
Effects of phosphorus pressure on the growth mechanism and the quality of the grown layers in gas source molecular beam epitaxial (MBE) growth of InP on (001) substrate are investigated. It is found that the normal growth process with the growth rate limited by indium flux intensity takes place only in a very narrow range of phosphorus supply. Outside this range, the growth rate depends also on phosphorus pressure. A significant decrease in growth rate under high phosphorus pressure is demonstrated to be due to oversaturation of the substrate surface by excess phosphorus. High phosphorus pressure deteriorates both the electrical and optical properties as well as the crystalline quality of the epitaxial layers. Incorporation of excessive phosphorus is shown to be responsible for deterioration, indicating that control of phosphorus pressure is very important for successful MBE growth of InP.