Modeling and simulation of high-bandwidth Si-based MOS/SOI photodetectors

A novel MOS photodetector structure is proposed to eliminate the diffusion current by taking advantage of SOI technology. The thick buried oxide stops the diffusion current from substrate and the thin absorption layer makes sure that the device is fully depleted during operation. The absorption region and ground electrode are separated by oxide and connected by buffer layer. The grid structure of Al gate electrode allows the light directly exposures on the absorption region. The device simulation is carried out by commercial software. From the result the SOI-MOS PD can have high bandwidth (22 GHz) and are fully compatible with ULSI technology.