Demonstration of TCAD Modeling for GaN Devices

Gallium Nitride (GaN) is a semiconductor material of which current knowledge is limited compared to more abundant, Silicon-based semiconductors. In order to add to our understanding of GaN, we aim to create a predictive room temperature GaN Schottky diode simulation model utilizing Silvaco Technology Computer-Aided Design's (TCAD) physical simulator. I-V data taken from fabricated GaN Schottky diodes serve as the basis for our preliminary simulation comparison based upon Ga N based physical models. From there I-V data from Circular TLM (CTLM) structures and C-V data allowed for the extrapolation of a Schottky barrier height and specific contact resistivity and these parameters were implemented into our final simulation. Through this investigation, it was discovered that a 2-D simulation structure, with equivalent area to a physical structure, can generate an I-V characteristic with an agreeable threshold voltage to the measured I-V characteristic. Further analysis is needed to resolve the discrepancies between specific on-resistance of the simulated and measured devices. Our research serves as a starting point in creating predictive simulation models in Silvaco TCAD which can be used to understand the physical phenomena which occur in GaN Schottky diodes.