0.18μm RF CMOS双向可控硅ESD防护器件的研究(英文)

Investigation on Bi-directional SCR ESD Protection Devices in a 0.18μm RF CMOS Process

基于传统双向可控硅(DDSCR)提出了两种静电放电(ESD)保护器件,可应对正、负ESD应力从而在2个方向上对电路进行保护。传统的DDSCR通过N-well与P-well之间的雪崩击穿来触发,而提出的新器件则通过嵌入的NMOS/PMOS来改变触发机制、降低触发电压。两种改进结构均在0.18μmRFCMOS下进行流片,并使用传输线脉冲测试系统进行测试。实验数据表明,这两种新器件具有低触发电压、低漏电流(～nA),抗ESD能力均超过人体模型2kV,同时具有较高的维持电压(均超过3.3V),可保证其可靠地用于1.8V、3.3V I/O端口而避免出现闩锁问题。

Based on the bi-directional silicon controlled rectifier（SCR）,two novel electrostatic discharge（ESD） protection devices have been proposed,which can prevent ESD stresses on both the positive and the negative directions.While the conventional dual-direction SCR ESD protection device is usually triggered by the avalanche breakdown between N-well and P-well,the two proposed devices use the embedded NMOS/PMOS as the triggering structure to decrease the trigger voltage.Both the modified structures are implemented in a 0.18μm RF CMOS process and examined by the transmission line pulse testing system.Experimental results indicate that the proposed devices have lower trigger voltage,smaller leakage current（～nA）,a protection level passing 2 kV of human body model,and a high holding voltage（3.3 V）,making them immune to the latch-up in 1.8 V or 3.3 V I/O ESD protection applications.