PRESSURE INDICATING FILM CHARACTERIZATION OF PRESSURE DISTRIBUTION IN EUTECTIC AU/SN WAFER-TO-WAFER BONDING

摘要

Pressure non-uniformity in a wafer to wafer bond chamber was characterized using pressure sensitive paper. The effect of poor pressure uniformity is discussed, and the nonuniformity was corrected for use in a eutectic Au/Sn based wafer-to-wafer bond. Several types of under solder metallization were also investigated, with Nb/Au seed metal providing the best overall result with good solder compression, liquid proof seal, and minimal solder spill-out. Thirdly, solder compression versus pressure applied was studied to achieve an excellent gap control (2 - 3 μm) between the bonded substrates.