High-speed waveguide-integrated Ge/Si avalanche photodetector

• 作 者: 丛慧 薛春来 刘智 李传波 步成文 王启明
• 机 构: State Key Laboratory on Integrated Optoelectronics, Institute of Semiconductors,Chinese Academy of S
• 出 处: Chinese Physics B
• 发表日期: 2016年05期
• 关键词: waveguide photodetector bandwidth multiplication breakdown compatible length cap

Waveguide-integrated Ge/Si heterostructure avalanche photodetectors(APDs) were designed and fabricated using a CMOS-compatible process on 8-inch SOI substrate. The structure of the APD was designed as separate-absorption-chargemultiplication(SACM) using germanium and silicon as absorption region and multiplication region, respectively. The breakdown voltage(V_b) of such a device is 19 V at reverse bias and dark current appears to be 0.71 μA at 90% of the V_b. The device with a 10-μm length and 7-μm width of Ge layer shows a maximum 3-dB bandwidth of 17.8 GHz at the wavelength of 1550 nm. For the device with a 30-μm-length Ge region, gain-bandwidth product achieves 325 GHz.

The structure of the APD was designed as a separate-absorption-charge multi-use (SACM) using germanium and silicon as The breakdown voltage (V_b) of such a device is 19 V at reverse bias and dark current appears to be 0.71 μA at 90% of the V_b. The device with a 10-μm length and 7- The thickness of Ge layer shows a maximum of 3-dB bandwidth of 17.8 GHz at the wavelength of 1550 nm. For the device with a 30-μm-length Ge region, gain-bandwidth product achieves 325 GHz.