夹断电压可调的高压结型场效应管

基于Double RESURF 700VBCD工艺平台,提出了一种夹断电压可调的高压结性场效应管(J-FET)。这种J-FET的夹断是通过栅源反偏引起的N阱(N-well)表面耗尽和衬源反偏引起的底部耗尽共同作用结果,故夹断电压可受J-FET的栅电位调制。同时通过改变高压J-FET的P型埋层(P-buried)掩膜窗口的大小和间距,来改变P-buried和N-well的杂质浓度分布,达到改变J-FET夹断电压的目的。在不增加工艺步骤和改变原有工艺条件的情况下,通过实验得到击穿电压大于700V,夹断电压在8V和17V之间可自由调整的高压J-FET器件。该器件可以作为启动器件和供电模块的线性调整器件使用。由于其夹断电压受P-buried注入版图尺寸的影响,同时受栅电位调制,所以可以满足线路设计者的不同要求。     

Kirk effect and suppressing for 20 V planar active-gap LDMOS Nie Weidong(聂卫东)1, 2, Yi Fayou(易法友)2, and Yu Zongguang(于宗光)1

For 20 V planar active-gap lateral double-diffused MOSFET（LDMOS）,the sectional channel is utilized to decrease the electric field in the n-drift region below the poly gate edge in the off-state,compared with the conventional single channel.Then the n-drift concentration can be increased to decrease the Kirk effect,while keeping off-state breakdown voltage V_bd unchanged.Meanwhile the influence of the n-drift concentration and the n-drift length L_drift（the drain n⁺ diffusion to gate spacing） which are related to the Kirk effect is discussed.The trade-offs between R_dson-Area,breakdown voltage V_bd and the electrical safe operating area（e-SOA） performance of LDMOS are considered also.Finally the proposed planar active-gap LDMOS devices with varied values of L_drift are experimentally demonstrated.The experimental results show that the Kirk effect can be greatly suppressed with slight increase in the R_dson·Area parameter.