用于3.3 V电源的高维持电压ESD防护器件

A High Maintenance Voltage ESD Protection Device for 3.3 V Power Supply

为了解决传统LVTSCR易发生闩锁效应的问题,提出了一种增强型嵌入P浅阱可控硅(EEPLVTSCR)结构。通过在传统LVTSCR中NMOS管漏极与阳极之间植入PSD/NSD有源区,引入了额外的复合作用,降低了发射极注入效率;通过NMOS管下方P浅阱增强基区的复合作用,同时降低了PNP、NPN管的电流增益,提高了维持电压。基于0.18μm BCD工艺,采用TCAD软件模拟了新型EEPLVTSCR和传统LVTSCR的电流电压(I-V)特性。仿真结果表明,新型EEPLVTSCR的维持电压从传统的1.73 V提升到5.72 V。该EEPLVTSCR适用于3.3 V电源的ESD防护。

In order to solve the problems of latch-up effect in the traditional LVTSCRs, an EEPLVTSCR structure was proposed. By inserting a PSD/NSD active region between the drain and anode of the conventional LVTSCR NMOS, an additional recombination action was introduced. The emitter injection efficiency was reduced. The base area recombination action was enhanced through the P shallow well below NMOS, while the current gain of PNP and NPN was reduced to improve the holding voltage. Based on a 0.18 μm BCD process, the current and voltage(I-V) characteristics of the new EEPLVTSCR and the traditional LVTSCR were simulated by TCAD simulation. Simulation results showed that the holding voltage of the new EEPLVTSCR was increased from the traditional 1.73 V to 5.72 V. The EEPLVTSCR was suitable for the ESD protection of 3.3 V power supply.