通过理论模拟CMOS工艺兼容的SiGe/Si 单光子雪崩二极管, 研究并讨论了掺杂条件对于电场分布、频宽特性、以及器件量子效率的影响。设计出具有浅结结构、可在盖革模式下工作、低击穿电压(30 V)的1.06 μm单光子技术雪崩光电二极管。 器件采用分离吸收倍增区结构, 其中Si材料作为倍增区、SiGe材料作为吸收区, 这充分利用了硅材料较高的载流子离化比差异, 降低了器件噪声;在1.06 μm波长下, SiGe探测器的量子效率为4.2%, 相比于Si探测器的效率提高了4 倍。仿真表明优化掺杂条件可以优化电场分布, 从而在APD击穿电压处获得更好的带宽特性。

The design of a CMOS-technology compatible SiGe/Si single photon avalanche photodiode was presented. The influence of doping condition on electric field distribution, the bandwidth characteristic and the quantum efficiency of detector were discussed in detail. A shallow-junction, Geiger-mode avalanche photodiode to provide single-photon-counting capability at 1.06 μm with a low-breakdown voltage(<30 V) was designed. A separate absorption and multiplication(SACM) structure was used to fabricate the SiGe/Si avalanche photodiodes, where Si material was taken as the multiplication region. Taking advantage of the higher silicon carrier ionization coefficient, noise was reduced, the quantum efficiency of SiGe detector is 4.2% at 1.06 μm, which has a 4 times enhancement compared with the Si detector. Simulation results indicate the optimum doping conditions can realize a suitable e-field distribution, thus obtaining good bandwidth characteristic at the required breakdown voltage of the APD.