Optimization and development of silicon-based semiconductor devices using TCAD

Computer simulation of the electrical and optical properties of semiconductor devices has been became as an essential tool for developing new device as well as for improving existing device. This presentation describes applications of physical device simulation: (1) design optimization of power MOSFET, which is single crystalline based silicon semiconductor device, for cryogenic temperature application and (2) two-dimensional device simulation of amorphous silicon based solar cell to develop novel photovoltaic device with high efficiency.;At first, details of the electrical properties and computer simulation of conventional and superjunction power MOSFET devices are presented in order to optimize their key parameters for cryogenic operation. Optimization of gate length and thickness of drift layer for room temperature and liquid nitrogen temperature is described. For second part, it is described that two-dimensional device simulation for amorphous silicon based solar cell devices is required since it has complicated device structure and inhomogeneous material such as amorphous or nano-/micro-crystalline materials. 2D/3D simulation of a single junction a-Si:H solar cell has been successfully established by using standard DOS model in order to model the continuous DOS. Upon the established a-Si:H model for TCAD, a novel structured a-Si solar cell has been suggested with introducing nanostuctured materials embedded in a-Si matrix absorber layer. The simulation results show that nanostructured material in amorphous matrix improves electrical properties of absorber layer allowing thick absorber layer resulting higher efficiency compared to conventional planar a-Si:H solar cells.