Growth of GaN and InGaN layers by rapid thermal MOCVD

A major limitation in the growth of InGaN-GaN heterostructures is the requirement for cyclic ramping of the growth temperature of similar to200 degreesC. In conventional systems this temperature ramping is slow, and part of the InGaN layer may degrade before next GaN layer is deposited. We present here data from a novel growth system that overcomes this limitation and allows the growth of a higher quality GaN and InGaN layers than produced in our system by a conventional process. The system is based on Rapid Thermal MOCVD (RT-MOCVD) in which two sets of high power tungsten-halogen lamps were used to radiatively heat a low thermal mass susceptor with ramp rates up to similar to250 degreesC/s. This allows the fabrication of heterostructures by using temperature as a switch in starting or terminating a process step rather than applying the gas phase switching technique normally used in the standard MOCVD technique. (C) 2003 WILFY-VCH Verlag GmbH & Co. KGaA, Weinheim.