High-speed metal-semiconductor-metal photodetector formed by silicon trenches

This paper demonstrates a brand new structure of metal-semiconductor-metal detector with 0.15 A/W responsivity at 790-nm wavelength and 2.15-GHz bandwidth at 10-V bias. Compared with conventional planar silicon MSM-PD, this detector is shown to have superior high-speed response and have comparable responsivity with only a simple modification. Most importantly, this detector can operate at 2 V with a slightly less bandwidth (1.25 GHz). Reducing the trench spacing to submicron size can increase the bandwidth at such a low bias. The ease of fabrication together with its high-speed performance at low operating voltages makes the structured MSM detector a strong candidate for optical receivers for short distance optical communication applications