一种25Gbit/s背入射高速InAlAs雪崩光电二极管

25Gbit/s Back-Side Illuminated High Speed InAlAs Avalanche Photodiode

摘要:

设计并制备了一种面向25Gbit/s长距离传输用背面进光高速InAlAs雪崩光电二极管(APD),芯片采用垂直台面吸收-渐变-电荷-倍增层分离(SAGCM)结构,通过刻蚀工艺形成三层台面,将电场限制在最大台面倍增层的中心,有效降低了台面边缘击穿风险。器件采用倒装焊结构,背面集成微透镜,以提高光耦合孔径。研制的APD芯片在增益M=1时,对1310nm波长光的响应度为0.84A/W；在M=10时,3dB带宽达到19GHz；增益带宽积为180GHz；在5×10-5误码率下最佳灵敏度为-22.3dBm,可支持100GBASE-ER4通信标准。

Abstract:

A high-speed back illuminating InAlAs avalanche photodiode(APD) was developed to meet the requirements of single-channel 25Gbit/s long-distance transmission. The APD adopts vertical back-illumination separate-absorption-grading-charging-multiplication (SAGCM) structure. Triple-layer mesa was formed by etching process, and the electric field was limited to the center of the maximum mesa multiplier layer, effectively reducing the mesa edge breakdown. The chip adopts reverse welding structure with integrated microlens on the back to improve optical coupling aperture. The responsivity of the developed APD chip is 0.84A/W (λ=1310nm) at the gain of M=1. When M=10,3dB bandwidth reaches 19GHz. The gain-bandwidth product is 180GHz. The best sensitivity at 5×10-5 bit error rate is -22.3dBm, which can support 100GBASE-ER4 communication standard.