DEVELOPMENT OF HIGHLY UNIFORM GaAs EPITAXIAL WAFERS WITH A THREE-INCH DIAMETER.

With the demand for high frequency and high output GaAs FETs for use in transmitters and receivers in satellite communications and microwave circuits, chip sizes are becoming large. In the manufacturing processes for FETs, to decrease the number of processes and improve the yield, it is desirable to increase the diameter and improve the uniformity of GaAs epitaxial wafers. The two-inch GaAs VPE (Vapor Phase Epitaxial growth) wafer has been produced as a material for FETs, and to meet the above-mentioned requirements three-inch VPE wafers have been developed. To make the reactor large enough for the development of the three-inch wafer, the vapor phase growth techniques accumulated over the last few years were put to use, and simulation software which analyzes gas flow and thermal flo in the reactor tube to optimize the growth conditions in the newly-designed, larger reactor tube was developed.