Physical modeling of MOS-controlled high-voltage devices for integrated circuit computer-aided design

This dissertation presents methodology for physical charge-based modeling of MOS-controlled high-voltage (HV) devices for integrated circuit (HVIC) computer-aided design (CAD). New models for two different MOS-controlled HV devices, the insulated-gate-bipolar transistor (IGBT) and the double-diffused MOS transistor (DMOST), are developed. The effects of the buffer layer and static/dynamic latch-up in the IGBT are characterized, and quasi-saturation, space-charge-limited current flow, and effects of the inherent BJT in both vertical and lateral DMOSTs are modeled. These effects, which are not properly represented in conventional equivalent-(sub)circuit models, are physically and sometimes semi-numerically accounted for in our models. Two-dimensional numerical device simulations were used extensively to study the effects and to aid the model development. The developed models are implemented in the circuit simulator 9P ICE via FORTRAN subroutines (UDCSs). With only known structural (device) parameters and crudely extracted model parameters, device/circuit simulations favorably predicted measured characteristics of test devices. The models in SPICE provide a capability of mixed-mode device/circuit simulation, which is not afforded by other equivalent-(sub)circuit models, and hence can facilitate computer-aided optimal device/circuit design of HVICs.