Gain estimation of RT-APD devices by means of TCAD numerical simulations

Abstract

The design of Reach-Through Avalanche Photodiodes (RT-APD) for medium energy X-ray detection requires a previous optimization to guarantee elevated gain at the required operation conditions. A simple methodology to estimate the gain in RT-APD devices by using TCAD numerical simulations is proposed in this work. This technique offers the possibility to predict the gain in RT-APDs as a function of the most relevant design considerations.

Low Gain Avalanche Detectors (LGAD) for particle physics and synchrotron applications

“…In this case the breakdown voltage is caused by the high electric field in the multiplication region between the n + implant and the p-type multiplication implant, as there are no edge effects present in the 1D simulated case. This simulation work agrees with the results shown in [6].…”

“…The bulk material is high resistivity p-type silicon (approximately 10 kOhm-cm) with a p + anode electrode on the backside. An example of the doping concentration through the n-type cathode and ptype multiplication implant is shown in figure 2 (taken from [6]). To understand the high-field performance of the device the concept of the effective p-type doping areal density, Q effective is helpful, illustrated in figure 2 and defined as the net p-type doping concentration integrated over the depth of the implant.…”

The research on linear gain of silicon avalanche photodetectors

“…Figure 5 shows the three types of guard ring structures. Reference [4] compared three types of guard ring (virtual guard ring, ion implantation, and trench), in which the trench guard ring has the optimal characteristics, but the surface defects brought by the trench will affect the other characteristics. We proposed the method of etching a suitable trench followed by ion implantation and annealing, andthis guard ring structure has reduced the lattice damages and lowered the dark currents because of an annealing process, therefore its performance is better than the other three guard rings.…”

“…The mesa structure has a good effect on suppressing surface edge electric fields, and the p-n junction is not easily pre-breakdown, but its reliability, breakdown voltage consistency, and gain stability are poor. The planar-type structure has a large optical gain-bandwidth product and better stability 4 . However, the electric field distribution of planar-type APD is not uniform and is prone to premature breakdown at the edge of the p-n junction 5 .…”