电力半导体场效应管瞬态响应特性研究

瞬态响应特性为电力半导体场效应管制约电路系统性能的关键电学参数。利用TCAD半导体器件仿真软件对电力半导体场效应管的瞬态响应特性进行了详细的研究。仿真结果表明，随着多晶硅栅区宽度的增大，栅—源电容充电时间较长，导通延迟时间随之延长。且栅—漏电容面积增大，栅—源电压维持时间随之增长，上升时间随之增长。导通延迟时间和上升时间均随着栅氧化层厚度的增大而大幅增大。为了在不影响导通电阻和导通延迟时间的情况下，缩短器件的上升时间，可采用非均匀厚度栅氧化层结构。随着厚栅氧化层厚度的增大，器件导通延迟时间基本相同，而上升时间随之显著缩短。随着厚栅氧化层宽度增大，器件导通电阻越高，漏—源等效电容放电时间越长。厚栅氧化层越宽，漏—栅等效电容对栅—源电容的充电时间影响越小，开通延迟时间越短。而对于上升时间，厚氧化层宽度存在最优值，此时miller耦合电容和导通电阻折中效果最优。

Transient response characteristics of power semiconductor MOSFET

Transient response characteristic is the key electrical parameter of power semiconductor MOSFET.In this paper，the transient response characteristics of power semiconductor MOSFET are studied in detail by using TCAD semiconductor device simulation software.The simulation results showed that as the width of poly gate region increases，the charging time of the gate-source capacitor is longer，and the conduction delay time increases accordingly.And the gate leakage capacity area increases，the gate-source voltage maintenance time increases，the rise time increases.Both the conduction delay time and the rise time increase greatly with the increase of the thickness of the gate oxide layer.In order to reduce the rise time of the device without affecting the conduction resistance and conduction delay time，the non-uniform thickness gate oxide structure can be used.With the thickness of the thick gate oxide layer increasing，the delay time of the device is basically the same，while the rise time decreases significantly.With the width of the thick gate oxide layer increasing，the higher the on resistance of the device，the longer the discharge time of the leakage source’s equivalent capacitance.The wider the thick gate oxide layer is，the less the influence of the leakage gate equivalent capacitance on the charging time of the gate-source capacitor is，and the shorter the opening delay time is.For the rise time，there is an optimal value for the width of the thick oxide layer，and the compromise effect between miller coupling capacitance and conduction resistance is optimal.