基于标准CMOS工艺的光敏传感单元结构的研究

基于0.6μm标准N阱CM O S工艺,研究了光敏管的结深及其侧墙结构对有源感光单元的感光面积百分比、光电响应信号幅值、感光灵敏度以及感光动态范围等参数的影响。研究了包括传统N+/P衬底的光敏管结构,以及网格状N+/P衬底,N阱/P衬底,网格状N阱/P衬底,P+/N阱/P衬底的光敏管结构。测试结果表明,不同深结深的光敏管结构,可以将器件感光灵敏度提高8~16.5 dB;网格状光敏管结构可以增加光敏管的侧墙面积,改善器件感光灵敏度;非网格状光敏管结构具有较低的暗电流和较大的感光动态范围,其中P+/N阱/P衬底光敏管结构的传感单元在变频两次扫描的工作方式下的感光动态范围可达139.8 dB。

Research of Photosensitive Sensors Structure Based on Standard CMOS Technology

In this paper,research of photosensitive sensors based on CSMC 0.6 μm N-well standard CMOS process is carried out.Research is focused on the effect of photodiode junction depth and lateral structure on sensor performance parameters,including fill factor,magnitude of photo-response,sensitivity and dynamic range.Traditional N_+/P-sub photodiode and grid N_+/P-sub,N-well/P-sub,grid N-well/P-sub,P_+/N-well/P-sub photodiodes structures have been researched.Measurement results show that: different deep junction depth photodiodes could increase the photo-sensitivity of the sensor by 8~16.5 dB;grid photodiodes structure could increase the lateral area of photodiodes and improve photosensitivity;un-grid photodiode has lower dark current and larger photosensitive dynamic range,the dynamic range of P_+/N-well/P-sub photodiode structure can be 139.8 dB when operating in reset frequency adjustment double scanning mode.