功率VDMOS器件漏电流、热阻与软焊料空洞率的关系  

The Relationship between Excessive Leakage Current,Large Thermal Resistance and Voids Rate

作　　者：谭稀 蒲年年[1] 徐冬梅 崔卫兵 王磊 朱宇鹏 柴彦科 刘肃[1] 

机构地区：[1]兰州大学微电子研究所,兰州730000 [2]华天微电子股份公司,甘肃天水74100

出　　处：《电子器件》2015年第1期37-43,共7页Chinese Journal of Electron Devices

基　　金：甘肃省科技重大专项项目(1203GKDE008)

摘　　要：现在被广泛应用的VDMOS器件存在诸多失效模式,主要表现为直流参数大漏电和热阻过高问题,限制了器件应用。通过对其失效器件进行X-RAY、SEM、EDS分析表征得到相关规律。研究结果表明空洞率相对较小时,漏电流大小、热阻值高低均与空洞率成正相关关系,只是随空洞率增长的趋势有所变化。构成器件的不同材料膨胀系数与导热率不同以及空气导热率较低是空洞率引起热阻值改变的主要原因;高热阻加速了Al的电迁移和可动污染离子移动,最终导致器件漏电流增大。Commercialized VDMOS failed to meet designed values for many reasons. Usual problems are excessive leakage current and large thermal resistance. Failed VDMOS was characterized using X-RAY,SEM and EDS. The relationship between excessive leakage current,large thermal resistance and voids rate was acquired. The results show leakage current and thermal resistance increase in direct proportion to voids rate when voids rate keeps in a low level,while the ratio changes. We attribute this to different dilatation coefficient and thermal conductivity of each material,as well as low thermal conductivity of air. Moreover,large thermal resistance will facilitate migration of Al and polluted ion,which causes increasing leakage current in turn.

关 键 词：VDMOS 大漏电 高热阻 空洞率 X-RAY SEM EDS 

分 类 号：TN305.94[电子电信—物理电子学] TN386.1