一种用于片上静电防护的新型闩锁免疫可控硅

A Novel Latchup-Immune SCR for On-Chip ESD Protection

可控硅(SCR)被广泛应用于片上静电放电(ESD)防护。由于SCR的低维持电压特性,闩锁问题一直是其应用于高压工艺ESD防护的主要问题。改进设计了一种新型SCR器件,即MOS High-holding Voltage SCR(MHVSCR)。通过对SCR寄生三极管正反馈进行抑制,并提高维持电压,实现了闩锁免疫。详细分析了MHVSCR提高SCR维持电压的可行性、工作原理以及实现步骤。基于Sentaurus TCAD的仿真结果表明:设计的器件将传统器件的SCR维持电压从2.8V提高至15.88V,有效实现了SCR在12V工艺下的闩锁免疫能力。

Silicon controlled rectifier（SCR）is widely used in on-chip electro-static discharge（ESD）protection.However,due to the characteristic of low holding voltage of SCR,latchup is a major issue of SCR for ESD in high voltage process.An improved novel device named MOS high-holding voltage SCR（MHVSCR）was proposed.Latchup immunity was achieved by inhibiting the positive feedback of the parasitic transistor of SCR with increased holding voltage.Concurrently,the feasibility of increasing the SCR’s holding voltage in MHVSCR,the working principle and the implementing procedures were presented.Based on Sentaurus TCAD tools,the simulation results showed that the proposed device’s SCR holding voltage was increased from the traditional 2.8 V to 15.88 V.Therefore,the latchup immunity was implemented effectively in the 12 V process.