Bonding support structure (and related process) for wafer stacking

A method for bonding semiconductor wafers, the method comprising:

• forming a plurality of stacked interlayer dielectric (ILD) layers on a first side of a first semiconductor wafer, wherein the plurality of stacked ILD layers have a first thickness over a central region of the first semiconductor wafer and a second thickness over peripheral regions of the first semiconductor wafer, the second thickness less than the first thickness;
• forming a ring-shaped bonding support structure comprising a layer of dielectric material over the peripheral regions after formation of one or more of the plurality of stacked ILD layers, wherein the layer of dielectric material has a sidewall facing a side of one or more of the plurality of stacked ILD layers;
• and
• bonding a second semiconductor wafer to the first side of the first semiconductor wafer.

A plurality of bonded together semiconductor wafers, comprising:

• a plurality of stacked interlayer dielectric (ILD) layers disposed over a central region of a first side of a first semiconductor wafer;
• a ring-shaped bonding support structure comprising a layer of dielectric material disposed over a ring-shaped peripheral region of the first semiconductor wafer, wherein the ring-shaped peripheral region of the first semiconductor wafer encircles the central region of the first semiconductor wafer, and wherein the layer of dielectric material has a sidewall facing a side of one or more of the plurality of stacked ILD layers;
• and
• a second semiconductor wafer bonded to the first side of the first semiconductor wafer.