Tera-Hertz Metal-Semiconductor-Metal Photodetectors

这项研究的目标是在我们初步成功的基础上，继续研究和开发指距和指宽均在100 nm以下的超高速金属-半导体-金属(MSM)光电探测器，工作在亚皮秒响应时间和太赫兹截止频率下，可以探测从可见光到红外的广泛波长范围。主要研究内容如下：(1)利用超高分辨率电子束光刻技术制备指距和指宽均小于100 nm的太赫兹MSM光电探测器，先在GaAs衬底上进行，然后在InGaP、InGaP衬底上进行。SOI(绝缘体上的硅)和不同响应波长的Si-Ge。(2)对提高探测器速度和灵敏度的因素进行了实验和理论研究。(3)研究了飞秒脉冲激光MSM光电探测器的动态性能。以及(4)使用超高速MSM探测器作为载体来研究电子和空穴在小于100 nm的指距之间以及在高电场中的弹道传输，特别是载流子速度过冲，并探讨了它们在提高探测器速度方面的应用。

The goal of this research is, based on our initial success, to continue investigating and developing ultra-high speed metal-semiconductor-metal (MSM) photodetectors that have a sub-100nm finger spacing and finger width, operate with a sub- picosecond response time and a tera-hertz cut-off frequency, and can detect a broad range of wavelengths from visible to infrared. The proposed research will focus on the following four aspects: (1) Fabricate tera-hertz MSM photodetectors with sub-100nm finger spacing and finger width using ulta-high resolution electron beam lithography, initially on GaAs, and later InGaAs,InGaP,SOI (Si on insulator), and Si-Ge for different response wavelengths. (2) Investigate experimentally and theoretically the factors that can increase the detectors' speed and sensitivity. (3) Investigate the dynamic performance of the MSM photodetectors using femto-second pulsed lasers. And (4) use the ulta-high speed MSM detectors as a vehicle to study ballistic transport of electrons and holes between a sub-100nm finger spacing and in a high electric field, particularly carrier velocity overshoots, and explore their application on improvement of detectors' speed.