Design and simulation result of n substrate reverse type avalanche photodiode (APD)

We present results of design and simulation of the n-substrate reverse type avalanche photodiode (APD), which internally amplifies the photocurrent by an avalanche process, with the diffusion and the epitaxial methods. We aim to develop the APD which is coupled with scintillating materials for X-ray and γ-ray detections. The purpose of this simulation is to investigate optimal design parameters including guarding of the reverse type APD to meet device performance requirement as one of detector components. These optimized conditions obtained from simulation study can be applied in fabrication of the reverse type APD. In this simulation, both process and device simulations of APDs have been done by using a 2D simulation package, Athena and Atlas, from Silvaco International. The n-substrate reverse type APD based on the optimized design parameters will be fabricated and tested in near future.