复合多晶硅栅LDMOS的设计

Design of a Dual-Material Gate LDMOS

提出了一种应用于射频领域的复合多晶硅栅LDMOS结构,并提出了具体的工艺实现方法。此结构采用栅工程的概念,设计的栅由S-gate和D-gate两块并列组成,S-gate用高功函数P型多晶硅材料,D-gate用低功函数N型多晶硅材料。MEDICI模拟结果表明,该结构能够降低沟道末端和漏极附近的最高电场强度,提高器件的跨导和截止频率;同时,还能够提高器件的击穿电压,并减小器件的热载流子效应。

A novel dual-material gate LDMOSFET （DMG-LDMOS） structure for RF application is proposed, along with its process technology. Using the concept of gate engineering, the gate of the DMG-LDMOS consists of S-gate （the first gate approaching source with high work-function material p^＋ polysilicon） and D-gate （the second gate approaching drain with low work-function material n^＋ polysilicon）. MEDICI simulation shows that the DMG- LDMOS can reduce the peak electric field at the end of the channel and around the drain, and improve transconductance and cutoff frequency of the device. Meanwhile, this structure can increase breakdown voltage of the device and reduce its hot carrier effect.