同步整流电路中SGT MOSFET尖峰震荡的优化设计  

Optimal design of spike oscillation for SGT MOSFET in synchronous rectification circuit

作　　者：商世广 王洋菲 马一洁 刘厚超 段兵青 SHANG Shiguang;WANG Yangfei;MA Yijie;LIU Houchao;DUAN Bingqing(School of Electronic Engineering,Xi’an University of Posts and Telecommunications,Xi’an 710121,China;Wayon Semiconductor Co.,Ltd.,Shanghai 201207,China)

机构地区：[1]西安邮电大学电子工程学院,陕西西安710121 [2]上海维安半导体有限公司,上海201207

出　　处：《西安邮电大学学报》2024年第2期64-73,共10页Journal of Xi’an University of Posts and Telecommunications

基　　金：陕西省重点研发计划项目(2022GY-002)。

摘　　要：针对同步整流电路中屏蔽栅沟槽型场效应晶体管(Shielded Gate Trench Metal-Oxide-Semiconductor Field Effect Transistor,SGT MOSFET),在工艺加工过程中形成的热氧结构导致控制栅极电压尖峰震荡幅度大、电路能量转换效率低等问题,提出了一种SGT MOSFET电压尖峰震荡的优化设计。采用电路仿真的方法,以分析电容对电路电压开关震荡的影响;采用拉偏结构参数的方法,以确定器件的工艺参数;采用增加湿法刻蚀屏蔽栅多晶硅和注入多晶硅两道工艺的方法,以消除热氧结构,减小器件电容,从而减小器件在电路中的电压尖峰震荡幅度和时间,提升电路的能量转换效率。实验结果表明,优化设计后的栅漏电容减小了约43%,控制栅极电压的尖峰震荡降低了约56%,电路能量转换效率提升了约4.6%,器件剖面扫描电镜(Scanning Electron Microscope,SEM)图表明,所提设计方法可以消除SGT MOSFET的热氧结构。In order to solve the problem of high voltage spike oscillation and low circuit energy conversion efficiency caused by the hot oxygen structure formed in shielded gate trench metal-oxide-semiconductor field effect transistor(SGT MOSFET)in synchronous rectifier circuit,an optimized design of SGT MOSFET voltage spike oscillation is proposed.The influence of voltage on the oscillation of circuit voltage switch is analyzed by circuit simulation.The process parameters of the device are determined by the method of pulling the structure parameters.The energy conversion efficiency of the circuit is improved by increasing the wet etching of shield gate polysilicon and the injection polysilicon to reduce the thermal oxygen structure,the device capacitance,so as to decrease the amplitude and time of voltage spike oscillation in the circuit.Experiment results show that the gate-drain capacitance is reduced by about 43%,the spike oscillation of the control gate voltage is reduced by about 56%,and the energy conversion efficiency of the circuit is improved by about 4.6%.The device profile scanning electron microscope(SEM)image shows that the hot oxygen structure of SGT MOSFET can be eliminated by the proposed method.

关 键 词：屏蔽栅沟槽型场效应晶体管 同步整流电路 电压尖峰震荡 热氧结构 湿法刻蚀 

分 类 号：TN386.1[电子电信—物理电子学]