设计了一种Ge/Si波导集成型雪崩光电二极管(APD)。器件采用将Si波导层置于Ge吸收层之下的结构,光经波导层进入吸收层只需一次耦合,降低了光的损耗,提高了光的吸收率和光电流。采用silvaco软件对器件的结构和性能进行仿真,结果表明:器件的雪崩击穿电压为-28V,最大内量子效率达到89%,在1.15~1.60μm范围内具有较高响应度,峰值波长位于1.31μm,单位响应度最高达0.74A/W,3dB带宽为10GHz。 A Ge / Si waveguide integrated avalanche photodiode (APD) was designed. The device adopts the structure that the Si waveguide layer is disposed under the Ge absorption layer. Only one coupling of the light into the absorption layer through the waveguide layer reduces the light loss, improves the light absorption rate and the photocurrent. The structure and performance of the devices were simulated by using silvaco software. The results show that the device has an avalanche breakdown voltage of -28V and a maximum internal quantum efficiency of 89% with a high responsivity of 1.15 ~ 1.60μm and a peak wavelength of 1.31 μm, unit responsivity of up to 0.74A / W, 3dB bandwidth of 10GHz.