通过理论分析,建立了双极型硅器件的ESD损伤模型,表明ESD对该类器件的损伤主要是过热失效模式。ESD电压较高时,静电放电电流引起局部过热导致PN结峰值温度达到硅的熔融温度(1 413℃)而使器件击穿烧毁;ESD电压较低时,电触点的峰值温度超过铝硅共晶的熔融温度(577℃),使器件参数退化从而发生潜在性失效。将实验结果与模型分析比较,结果吻合良好。因此,在知道器件生产工艺参数的情况下,就可计算出器件的ESD损伤阈值,为双极型硅器件的设计、参数优化提供了理论依据。
We have investigated the failure mechanisms of Bipolar Silicon Device caused by Electrostatic Discharge(ESD) and built the mathematical model.It has been proved that thermal breakdown is the main failure of those devices.When the ESD voltage is high,local hot spots begin to occur and the peak temperature in these regions very quickly reaches the silicon melt temperature(about 1 413℃) and permanent damage is incurred.When the ESD voltage is low,the peak temperature of the contact reaches the aluminum-silicon eutectic temperature(about 500 ℃) that can result in the aluminum forming a spike through the diffusion,and latent failure will occur.There is a good agreement between the mathematical model and the experimental result.So,the ESD damage threshold of Bipolar Silicon Device can be calculated if the process parameters are got.As a result,the model provides theoretical basis for the design and parametric optimization of devices.