LOW DARK CURRENT QUASI-SCHOTTKY BARRIER MSM-PHOTODIODE STRUCTURES ON N-GA0.47IN0.53AS WITH P+-GA0.47IN0.53AS CAP LAYER

The p+-cap layer was used to fabricate a metal-semiconductor-metal (MSM) interdigitated photodetector on Ga0.47In0.53As. The measured barrier height was PHI(Bn) = 0.52 V, the ideality factor n = 1.1 and average dark current density 2 mA/cm2. A rise time of 45 ps at lambda = 1.3-mu-m under 2 V bias was measured for an MSM photodiode with 3-mu-m finger width and finger gaps and an active area of 100 x 100-mu-m2.