中国物理B ›› 2011, Vol. 20 ›› Issue (2): 28501-028501.doi: 10.1088/1674-1056/20/2/028501
Florin Udrea1, 罗小蓉2, 姚国亮2, 陈曦2, 王琦2, 葛瑞2
Luo Xiao-Rong(罗小蓉)a)†,Yao Guo-Liang(姚国亮)a),Chen Xi(陈曦)a), Wang Qi(王琦)a),Ge Rui(葛瑞)a),and Florin Udreab)
摘要: A low specific on-resistance (RS,on) silicon-on-insulator (SOI) trench MOSFET (metal--oxide--semiconductor--field--effect--transistor) with a reduced cell pitch is proposed. The lateral MOSFET features multiple trenches: two oxide trenches in the drift region and a trench gate extended to the buried oxide (BOX) (SOI MT MOSFET). Firstly, the oxide trenches increase the average electric field strength along the x direction due to lower permittivity of oxide compared with that of Si; secondly, the oxide trenches cause multiple-directional depletion, which improves the electric field distribution and enhances the reduced surface field (RESURF) effect in the SOI layer. Both of them result in a high breakdown voltage (BV). Thirdly, the oxide trenches cause the drift region to be folded in the vertical direction, leading to a shortened cell pitch and a reduced RS,on. Fourthly, the trench gate extended to the BOX further reduces RS,on, owing to the electron accumulation layer. The BV of the MT MOSFET increases from 309 V for a conventional SOI lateral double diffused metal--oxide semiconductor (LDMOS) to 632 V at the same half cell pitch of 21.5 μ m, and RS,on decreases from 419 mΩ·cm2 to 36.6 mΩ·cm2. The proposed structure can also help to dramatically reduce the cell pitch at the same breakdown voltage.
中图分类号: (Semiconductor-device characterization, design, and modeling)