一种高带宽NP 型CMOS APD 的研究
NP type CMOS APD with high frequency bandwidth
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摘要: 提出了一种高带宽的硅基CMOS雪崩光电二极管(APD)器件。该器件在N阱/P衬底基本结构的基础上,增加一个N型深掩埋层,并在该掩埋层单独加上电压,以减小载流子的输运时间。通过理论分析确定了器件的结构参数,通过器件性能的仿真分析对相关参数进行了优化设计。仿真结果表明:采用标准0.18 m CMOS工艺,所设计的APD器件的窗口尺寸大小为20 m20 m,在反向偏压为16.3 V时,器件的雪崩增益为20,响应度为0.47 A/W,3 dB带宽为8.6 GHz。Abstract: A newly modificated silicon (Si) avalanche photodetector (APD) desinged by standard complementary metal-oxide-semiconductor (CMOS) process was proposed in this paper. The basic structure of the Si APD which was formed by N-well/P-substrate was modificated with a deep N well below space charge area, and a independent voltage was applied on the deep N well to minish the transit time of electron hole pairs. The diffusion velocity and the drifting velocity can be improved at the same time, therefore, the 3-dB bandwidth will increase. The device parameters of CMOS APD were calculated with theoretical analysis, and the performance of the CMOS APD was optimized with SILVACO simulation, including technology simulation and device simulation. The simulation results show that when the window size of designed APD is 20 um 20 um and when biased at 16.3 V, the APD achieves avalanche gain of 20, the best responsivity of 0.47 A/W,the 3 dB bandwidth of 8.6 GHz.