硅/硅直接键合的界面应力

Research and progress of the interfical stresses of silicon direct bonding

硅/硅直接键合技术广泛应用于SOI,MEMS和电力电子器件等领域,键合应力对键合的成功和器件的性能产生很大的影响。键合过程引入的应力主要是室温下两硅片面贴合时表面的起伏引起的弹性应力;高温退火阶段由于两个硅片的热膨胀系数不同引起的热应力和由于界面的本征氧化层或与二氧化硅键合时二氧化硅发生粘滞流动引起的粘滞应力。另外,键合界面的气泡、微粒和带图形的硅片键合都会引入附加的应力。

Silicon direct bonding technology is extensively applied to SOI,MEMS and high power devices. The stress induced during bonding have a large effect on the bonding yield and the properties of devices. It is found by experiments that the stress induced by bonding mainly are the elastic stress due to the surface morphology,the thermal stress due to the difference in thermal expansion coefficient of the two silicon wafers and the viscoelastic stress due to the oxide flowing during high temperature annealing. In addition,the additional stress will be induced because of the interface bubble,the particles and the patterned silicon wafers bonding.