Integratable SiGe phototransistor with high speed (BW=3 GHz) and extremely-high avalanche responsivity

Abstract

In this paper, we discuss about the SiGe phototransistors (HPT) with SiGe/Si multiple quantum well (MQW) absorption layers and integratable SiGe phototransistor with high speed (BW=3 GHz) and extremely-high avalanche responsivity have been demonstrated. The properly designed non-ideal (nkT) base current can increase the speed of HPT, and have an avalanche bias with extremely high gain. The bandwidth of 3 GHz at normal bias is obtained with transistor's f/sub T/ of /spl sim/ 70 GHz. The integrated photoreceiver using commercial SiGe/Si HBT foundry is feasible.