一种用于高压防护的新型闩锁免疫LDMOS

A Novel Latch-Immune LDMOS for High-Voltage Protection

横向双扩散MOSFET(LDMOS)由于其高击穿电压特性而被认为是适合在高压中应用的防止静电放电(ESD)现象的保护器件。在传统结构中,LDMOS的鲁棒性相对较差,这是器件自身固有的不均匀导通特性和Kirk效应导致的。可将可控硅整流器(SCR)嵌入到LDMOS结构(即NPN;DMOS)中。然而,SCR固有的正反馈效应会导致其维持电压较低,增加了被闩锁的风险。提出了一种基于NPN;DMOS的新型器件,可以实现更高的维持电压以及较小的占用面积。基于TCAD进行仿真,实验结果表明,在不增加芯片面积的情况下,器件的维持电压从7.3 V增加到22.5 V。这证明了提出的结构具有出色的抗闩锁能力。

Due to the high breakdown voltage characteristics of the laterally diffused metal oxide semiconductor(LDMOS), this device is a protection device that prevents electrostatic discharge(ESD) in high-voltage applications. In the traditional structure, the robustness of LDMOS is relatively poor, which is caused by the inherent uneven conduction characteristics of the device itself and the Kirk effect. The silicon-controlled rectifier(SCR) can be embedded in the LDMOS structure to become the NPN;DMOS structure. However, the inherent positive feedback effect of the SCR will cause its holding voltage to be lower and increase the risk of latch-up. A new type of device based on NPN;DMOS was proposed, which could achieve a higher holding voltage and a small area. Based on TCAD simulation, the simulation TLP experimental results showed that the holding voltage of the device was increased from 7.3 V to 22.5 V, and the chip area was not increased, which proved that this structure had excellent immune latch-up capabilities.