High-speed InP/GaInAs heterojunction phototransistor on InP-on-Si grown by organometallic vapor phase epitaxy

Abstract
We have fabricated the first heterojunction phototransistor (HPT) on InP-on-Si. These phototransistors, based on the InP/GaInAs heterojunction, have optical gains as high as 125 A/W at 1300 nm and dark currents as low as 300 pA, for a 48×64 μm HPT. The bandwidth was determined from impulse photoresponse measurements to be 4.4 GHz. The intrinsic bandwidth was estimated from the zero bias capacitance (0.2 pf) to be as high as 16 GHz.