HIGH-PERFORMANCE LARGE-AREA INGAAS MSM PHOTODETECTORS WITH A PSEUDOMORPHIC INGAP CAP LAYER

We report the fabrication and characteristics of high-performance InGa As MSM photodetectors with a 300-mu m x 300-mu m square and a 300-mu m -diameter circular detection area, With a pseudomorphic In0.9Ga0.1P ca p layer, the detectors exhibit dark current densities less than 1 pA/m u m(2), The responsivity ranges between 0.4 and 0.6 A/W depending on f inger spacing, Bandwidth over 1 GHz has been obtained for these large- area detectors, Our results also show that the circular detector exhib its better speed performance as compared to the square one due to its smaller parasitic RC constant.