Inhomogeneous GaAs FET Threshold Voltages Related to Dislocation Distribution

Abstract
Clear correlation between dislocation distribution and FET threshold voltage distribution in undoped LEC GaAs was observed directly for the first time by automatic computer-controlled measurement of drain-source current (I ds) and threshold voltage (V th). FETs fabricated in the high EPD area, which covers the center and the periphery of (100) wafers, showed high I ds and low V th, whereas FETs fabricated in the low EPD area showed low I ds and high V th.