Patent attributes
Techniques and mechanisms for bonding a first wafer to a second wafer in the presence of a fluid, the viscosity of which is greater than a viscosity of air at standard ambient temperature and pressure. In an embodiment, a first surface of the first wafer is brought into close proximity to a second surface of the second wafer. The fluid is provided between the first surface and the second surface when a first region of the first surface is made to contact a second region of the second surface to form a bond. The viscosity of the fluid mitigates a rate of propagation of the bond along a wafer surface, which in turn mitigates wafer deformation and/or stress between wafers. In another embodiment, the viscosity of the fluid is changed dynamically while the bond propagates between the first surface and the second surface.