Electric Field Reduction in C-Doped AlGaN/GaN on Si High Electron Mobility Transistors

It is shown by simulation supported by experiment that a reduced surface field effect, associated with compensated deep acceptors, can occur in carbon doped GaN-on-Si power switching AlGaN/GaN transistors, provided there is a vertical leakage path from the 2DEG to the carbon-doped layer. Simulations show that this effect is not present in devices using iron-doped GaN buffers explaining the higher voltage capability of carbon-doped devices.