Stress control of plasma enhanced chemical vapor deposited SiO2 film in through silicon via process

Through silicon via is an essential element for three dimension integration. Excessive stress have potential effects on the reliability of the structure. One concern is the peeling problem of SiO₂ layer. It was found that it is caused by the electroplated copper during later solder reflow process. We also found that it is possible to ameliorate the peeling problem by increasing the compressive stress in the SiO₂. We found that the peeling problem is solved when SiO₂ was deposited with higher compressive stress. Compared to 90% peeling off for compressive stress -20 MPa in the SiO₂, Only 20% peeling off for compressive stress -40 MPa in the SiO₂ and no peeling off for compressive stress -110 MPa and -150 MPa in the SiO₂.