PIN探测器和跨阻放大器的光电单片集成

Photoelectric monolithic integration of PIN detector and transimpedance amplifier

设计了一种大面积、高响应度的硅基PIN探测器,PIN探测器的表面积为4.1 mm×13.8 mm,整体厚度为420μm左右。PIN探测器的光敏面采用环形Al电极将光电流信号引出,通过在波长为860 nm的恒定激光光源下进行测试,其响应度为0.6 A/W。提出了一种全新的光电单片集成的可行性方法,即利用PIN探测器非光照区的本征Ⅰ层面积,设计了一种与PIN探测器结构和工艺兼容的跨阻放大器,在保证了PIN探测器结构和性能没有发生改变的前提下,实现了PIN探测器和跨阻放大器的光电单片集成。最后在波长为860 nm、脉冲宽度为100 ns、工作频率为10 kHz的实际脉冲激光信号下对流片成功的PIN探测器和光电单片集成芯片的脉冲响应进行了对比测试。结果表明:在脉冲宽度基本没有发生变化的同时,光电单片集成芯片的脉冲电压信号相比于PIN探测器的脉冲光电流信号放大了1 000倍,放大倍数和理论的跨阻阻值1 000Ω一致。该集成光电芯片应用在激光引信系统的激光接收模块中,通过光电单片集成可以提高PIN探测器上输出端信号的信噪比,增强系统的稳定性,同时也可以满足激光引信系统小型化发展的需要。

A silicon-based PIN detector was designed, which had large area and high response, the surface area of the PIN detector was 4.1 mm×13.8 mm, and the thickness was about 420 μm. The ring-shaped Al electrode was used to extract the photocurrent signal in the photosensitive surface of the PIN detector. The test was performed under a constant laser light source with a wavelength of 860 nm, and its responsivitywas 0.6 A/W. Next, a new feasibility method for photoelectric monolithic integration was proposed, that is, by using the intrinsic I layer area of the non-illuminated area of the PIN detector, a transimpedance amplifier compatible with the structure and process of the PIN detector was designed, the photoelectric monolithic integration of the PIN detector and the transimpedance amplifier was realized on the premise that the structure and performance of the PIN detector had not changed. Finally, under the actual pulsed laser signal with a wavelength of 860 nm, a pulse width of 100 ns,and a working frequency of 10 kHz, the pulse response of the successful tape-out PIN detector and the photoelectric monolithic integrated chip was compared and tested. The results show that the pulse voltage signal of the photoelectric monolithic integrated chip is amplified by 1 000 times compared with the pulse photocurrent signal of the PIN detector, while the pulse width is basically unchanged, the amplification factor is consistent with the theoretical transimpedance value of 1 000 Ω. The integrated photoelectric chip is used in the laser receiving module of the laser fuze system. Through photoelectric monolithic integration, the signal-to-noise ratio of the output signal on the PIN detector can be improved, and the stability of the system can be enhanced, it can also meet the needs of the miniaturization of the laser fuze system.