Broad-bandwidth, high-responsivity intermediate growth temperature GaAs MSM photodetectors

In this letter, we report the design, fabrication, parametric testing, and analysis of a intermediate growth temperature (IGT) GaAs MSM photodetectors. The broad-area, ultrafast photodetector displays linear and nonlinear photocurrent generation characteristics as a function of applied bias and optical power. The photocurrent/dark current ratio 7/spl times/10/sup 3/ is significantly larger than normal growth temperature or low growth temperature 200/spl deg/C based GaAs MSM's. The optical responsivity of 130 mV/pJ Is the highest ever reported for similar ultrafast MSM photodetectors. This device is uniquely suited for high-speed, high-photocurrent applications, such as optoelectronic trigger sources for phased-array antenna systems.