Improved resolution method to study at 3D the conduction phenomena inside GaAs PIN photodiode

GaAs PIN photodiodes are presently receiving much attention for low-noise photoreceivers. In this paper, specific feature of GaAs-based PIN photodiodes are given, in particular on the investigation of the GaAs properties. In order to show the potentialities of the GaAs PIN photodiode, a three-dimensional resolution and simulation are realized. The simulation adopted the drift–diffusion model applied to transport equations for semiconductor P+–ν–N+ structure under illumination. The generation term is the function of the incidental flow, reflection, and absorption coefficients. We developed subroutines in the simulation program (SIM 3D) attended for the simulation of the transport phenomena inside the PIN structure using the combined Newton–Gummel method, which uses the electrostatics potentials and the normal variables. These programs are implemented in the simulator to simulate the conduction inside the GaAs PIN photodiode. The model is applied on the carriers’ minority at high injection. The electric field and the photocurrent are then calculated. At the end we have characterized electrically the PIN photodiode from the results of the simulation, to show its band-width and then its domain of use.