Fused InGaAs-Si avalanche photodiodes with low-noise performances

A fused InGaAs-Si avalanche photodiode (APD) with a low excess noise factor of 2.3 at a gain of 20 is reported. This corresponds to a k factor of 0.02 for the silicon avalanche region. Dark current density as low as 0.04 mA/cm/sup 2/ at -5 V and 0.6 mA/cm/sup 2/ at a gain of 10 are measured; a small thermal coefficient, 0.09%//spl deg/C, of the breakdown voltage is observed for this APD.