Simulation of quasi-stationary and transient effects in gan based heterostructure field effect transistors

Numerical simulations to compute stress distributions resulting from stressed overlayers reveal that significant stress fields can penetrate deep into device. Piezoelectric polarization effects from stressed overlayers are only mild due to relatively high stiffness in nitrides but can change band profile along the channel, especially under gate edges. Fringing fields in passivation layers with large dielectric constants can play important role in collapse reduction.