Refining EBIC Analysis of GaN p-n Junctions Through Numerical Simulations

Spatial distribution of electron beam induced current (EBIC) across p-GaN/n-GaN junctions is studied by 3D numerical simulations using the Monte Carlo (MC) method. The influence of beam and sample specific parameters on EBIC line profiles is examined to provide insights into the charge carrier generation, diffusion, and collection at the p-n junction. Among various parameters influencing the EBIC signal, in this paper we focus on the effect of the space charge region (SCR) on both the intensity and spatial distribution of the EBIC signal. Wider SCRs lead to flat-topped maxima shifted toward the lower doped region and problematic estimation of physical p-n junction position, whilst narrower SCRs result in a reduced signal intensity due to decreased collection efficiency.