The purpose of this paper is to characterize pressure non‐uniformity in a wafer‐to‐wafer bond chamber using pressure sensitive paper.
Pressure non‐uniformity in a wafer‐to‐wafer bond chamber is characterized using pressure sensitive paper. The effect of poor pressure uniformity is discussed, and the non‐uniformity 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. Solder compression versus pressure applied was studied to achieve an excellent gap control (2‐3 μm) between the bonded substrates.
This paper shows that characterization of applied pressure measured directly at the substrate is an important aspect in the development of high yielding bond processes.
