用于高压ESD保护的双向LDMOS_SCR结构

A Dual Direction LDMOS_SCR for High Voltage ESD Protection Device

基于横向双扩散金属氧化物半导体(LDMOS)的可控硅结构(LDMOS_SCR)因其较强的单位面积电流处理能力和出色的高压特性,通常用于高压下的静电防护。通过将原本浮空的漏极N+分割为对称的P+、N+和P+结构,提出了一种基于LDMOS_SCR的双向防护器件。该器件具有低触发和高维持电压。通过降低形成在栅极区域底部的寄生双极晶体管的发射极注入效率,减少了SCR固有的正反馈增益。基于TCAD进行仿真,实验结果表明,与传统的LDMOS_DDSCR相比,新型器件的触发电压从69.6 V降到48.5 V,维持电压从14.9 V提高到17 V,证明了提出的结构与传统LDMOS_DDSCR器件相比具有出色的抗闩锁能力。

The lateral double diffused MOSFET silicon controlled rectifiers(LDMOS_SCR)device structure was commonly used for electrostatic protection at high voltage due to excellent high voltage characteristics.The N+of the floating drain pole was divided into symmetric P+,N+and P+structures,and a dual directional protection of power device based on LDMOS_SCR with low trigger and high holding voltage was proposed.It reduced the emitter-injection efficiency of parasitic bipolar transistors formed at the bottom of the grid region,and the inherent positive feedback mechanism of the SCR was reduced.Based on TCAD simulation,the experimental results showed that,compared with the traditional LDMOS_DDSCR,the trigger voltage of the new device was reduced from 69.6 V to 48.5 V,and the holding voltage was increased from 14.9 V to 17 V.It was proved that the new structure had a good immunity ability of latch-up effect compared with the traditional LDMOS_DDSCR device.