SEMICONDUCTOR BONDING TOOL AND METHOD OF OPERATING THE SAME

A bag is filled with liquid, instead of an airbag filled with gas, to deform a bottom wafer toward a top wafer during a wafer bonding process. As a result, the liquid is less susceptible to temperature changes, which reduces run-out variation across wafer bonding processes. Reducing run-out variation conserves wasted wafers by increasing yield and reducing a quantity of non-functioning devices that are produced. Additionally, in some implementations, the liquid may be pre-heated before the bag is filled with the liquid. As a result, the bottom wafer (and, to some extent, the top wafer) experiences some thermal deformation and less mechanical deformation, which further increases yield and reduces a quantity of non-functioning devices that are produced.