Trench power MOSFET lowside switch with optimized integrated Schottky diode

This work investigates the device and circuit performance of an integrated MOSFET-Schottky diode solution for lowside switching, or synchronous rectifier, applications. The integrated diode structure is a trench MOS barrier Schottky (TMBS) device, and the area of the TMBS structure, as a ratio of the total active area, was the independent variable in this study, ranging from zero to 50%. The results of both simulation and experiments show that there is an optimum contribution of TMBS area which maximizes the performance of the integrated device. Initially, the results provided a strong correlation between TMBS contribution, diode recovery characteristics, and DC-DC converter efficiency. However, a closer examination of the underlying, device level current distribution waveforms, as well as the power loss mechanisms in the converter, reveal a more complex interaction of the TMBS structure and the MOSFET. It is only in the context of this analysis, that useful device design insight can be extracted.

[1]  T. Yachi,et al.  Conduction power loss in MOSFET synchronous rectifier with parallel-connected Schottky barrier diode , 1998 .

[2]  B. Jayant Baliga,et al.  Improving the reverse recovery of power mosfet integral diodes by electron irradiation , 1983 .

[3]  Krishna Shenai,et al.  Monolithically integrated power MOSFET and Schottky diode with improved reverse recovery characteristics , 1990 .

[4]  J. G. Kassakian,et al.  High-frequency high-density converters for distributed power supply systems , 1988 .

[5]  Alex Q. Huang,et al.  Novel automated optimization of power MOSFET for 12V input, high-frequency DC-DC converter , 2003, ISPSD '03. 2003 IEEE 15th International Symposium on Power Semiconductor Devices and ICs, 2003. Proceedings..

[6]  Krishna Shenai,et al.  High performance power DMOSFET with integrated Schottky diode , 1989, 20th Annual IEEE Power Electronics Specialists Conference.

[7]  M. Mehrotra,et al.  Very low forward drop JBS rectifiers fabricated using submicron technology , 1993 .

[8]  George C. Verghese,et al.  Modeling and simulation of power electronic converters , 2001, Proc. IEEE.

[9]  Toshiaki Yachi,et al.  Experimental investigation of dependence of electrical characteristics on device parameters in trench MOS barrier Schottky diodes , 1998, Proceedings of the 10th International Symposium on Power Semiconductor Devices and ICs. ISPSD'98 (IEEE Cat. No.98CH36212).

[10]  Bantval J. Baliga,et al.  On the reverse blocking characteristics of Schottky power diodes , 1992 .

[11]  Krishna Shenai,et al.  Current transport mechanisms in atomically abrupt metal-semiconductor interfaces , 1988 .

[12]  F.C. Lee,et al.  A MOSFET resonant synchronous rectifier for high-frequency DC/DC converters , 1990, 21st Annual IEEE Conference on Power Electronics Specialists.

[13]  Yu Wu,et al.  Fast reverse recovery body diode in high-voltage VDMOSFET using cell-distributed Schottky contacts , 2003 .

[14]  M. Brkovic,et al.  High frequency synchronous buck converter for low voltage applications , 1998, PESC 98 Record. 29th Annual IEEE Power Electronics Specialists Conference (Cat. No.98CH36196).