The Research And Design Of Trench DMOS

The driving forces for advantages in power semiconductor technology are improvements in efficiency, size and weight within stringent cost and manufacturing constraints. Applications such as computers, teclecommunication and automotive industry have steered the growth of effient low voltage power semiconductor devices operating below 200 Volts and put increasing demand on improved efficiency. Trench DMOS is one of the important power semiconductor devices developed upon VDMOS and VMOS. Compared with the traditonal planar power devices, sub-micro technology is widely used for manufacturing Trench DMOS and the production process is more complex. Trench DMOS has been widely used because it has high switch speeds, low on resistance, square safe operating area and non latching behavior.First, the electrical characteristics of Trench DMOS are studied and then the physical models are defined. These physical models offer theoretically basis for the design of Trench DMOS. The channel and epitaxy layer are also optimized to decrease the on resistance. In addition, a 2D analytical threshold voltage model of Trench MOSFET devices is proposed. The simulation shows that this model overcomes former inaccuracy of Trench MOS threshold voltage model and is suitable for the trench mosfet with short channels.The Trench DMOS is designed according to the requirements of performance criteria, such as vertical parameters, horizontal parameters, terminal structure, production technology and layout. Then, process simulation and optimization are carried out using Silvaco's TCAD tools. At last, the electrical parameters, such as threshold voltage and breakdown voltage, are simulated to verify the former design results.