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
商世广 1王洋菲 1马一洁 2刘厚超 2段兵青2
作者信息
- 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
- 折叠
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.
Abstract
In order to solve the problem of high voltage spike oscillation and low circuit energy con-version 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 oscil-lation of circuit voltage switch is analyzed by circuit simulation.The process parameters of the de-vice are determined by the method of pulling the structure parameters.The energy conversion effi-ciency of the circuit is improved by increasing the wet etching of shield gate polysilicon and the in-jection 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Key words
SGT MOSFET/synchronous rectifier circuit/voltage spike oscillation/thermal oxygen structure/wet etching引用本文复制引用
基金项目
陕西省重点研发计划(2022GY-002)
出版年
2024
NETL
NSTL
万方数据