SiGe工艺中HBT结构ESD保护电路设计

为有效控制生产成本,减少工艺步骤,提出了在SiGe工艺中,用SiGe异质结双极型晶体管(HBT)代替传统二极管来实现静电放电(ESD)保护的方案。通过设计不同的HBT器件的版图结构,以及采取不同的端口连接方式,对HBT单体结构防护ESD的能力强弱和其寄生电容大小之间的关系进行了比较分析,并从中找出最优化的ESD解决方案。应用于实际电路中的验证结果表明,此方案在ESD防护能力达到人体模型(HBM)2 kV的基础上,I/O(IN/OUT输入输出)端口的寄生电容值可以做到200 fF以下,且此电容值还可通过HBT串联模式进一步降低。

Design on the ESD Protection Circuit with HBT Structure in SiGe Process

To reduce the cost and process step,a scheme was proposed to replace the traditional diode with heterogeneous bipolar transistor(HBT) device on SiGe process.By designing different HBT layout structures and different device connection styles,the relationship between HBT device electrostatic discharge(ESD) protection performance and its parasitic capacitance was found.Based on the data analysis,the optimized ESD solution was proposed.After circuit level verification,good results are achieved that ESD capability can pass human body model(HBM) 2 kV and the I/O parasitic capacitance is below 200 fF.The capacitance can be even lower by connecting the HBT device in series.