Monolithically integrated SiGe/Si PIN-HBT front-end transimpedance photoreceivers

The demand for monolithically integrated photoreceivers based on Si-based technology keeps increasing as low cost and high reliability products are required for the expanding commercial market. Higher speed and wider operating frequency range are expected when SiGe/Si heterojunction is introduced to the circuit design. In this paper, a monolithic SiGe/Si PIN-HBT front-end transimpedance photoreceiver is demonstrated for the first time. For this purpose, mesa-type SiGe/Si PIN-HBT technology was developed. Fabricated HBTs exhibit f_max of 34 GHz with DC gain of 25. SiGe/Si PIN photodiodes, which share base and collector layers of HBTs, demonstrate responsivity of 0.3 A/W at λ=850 nm and bandwidth of 450 MHz. Based on these devices, single- and dual-feedback transimpedance amplifiers were fabricated and they exhibited the bandwidth of 3.2 GHz and 3.3 GHz with the transimpedance gain of 45.2 dBΩ and 47.4 dBΩ, respectively. Monolithically integrated single-feedback PIN-HBT photoreceivers were implemented and the bandwidth was measured to be ~0.5 GHz, which is limited by the bandwidth of PIN photodiodes