Computer Simulation of Space-Charge-Limited I-V Characteristics in Semi-Insulating InP Films

Current-voltage (I-V) characteristics of epitaxial layers grown by either hydride vapor phase epitaxy (HVPE) or metal-organic chemical vapor phase deposition (MOCVD) were examined. The HVPE data were simulated using a two trap model with trap levels at 0.660.68 eV and at 0.3-0.33 eV. Programs were also written using the differential form of Gauss' law and two variations of it. These Gaussian programs required a longer execution time; and an appropriate current range was not easily determined. In contrast, modifications could be made directly to the Gaussian programs. Both sets of programs generated identical graphs. Unfortunately, the MOCVD data could not be simulated using a single trap level at 0.66-0.68 eV as predicted. The shape of the curve was matched, but only at a much lower voltage range. Finally, a least-squares fit program was written to determine the "fit" of the simulated graphs.