Gas-controlled bonding platform for edge defect reduction during wafer bonding

A wafer bonding method, the method comprising:

• placing a top wafer on a top bonding framework, the top bonding framework including a first plurality of outlet holes and a second plurality of outlet holes around a periphery of the top bonding framework;
• placing a bottom wafer on a bottom bonding framework, the bottom bonding framework including a plurality of inlet holes around a periphery of the bottom bonding framework;
• wherein the top bonding framework is in overlapping relation to the bottom bonding framework such that a gap exist between the top wafer and the bottom wafer;
• adding a flow control device to the first plurality of outlet holes, the flow control device monitors flow conditions of a gas stream and blocks the first plurality of outlet holes;
• adding a pumping device to a second plurality of outlet holes, the pumping device prevents back diffusion of moisture into the gap between the top wafer and the bottom wafer;
• and
• circulating the gas stream through the gap between the top wafer and the bottom wafer, the gas stream entering the gap through one or more of the plurality of inlet holes and exiting the gap through one of more of the second plurality of outlet holes;
• wherein the gas stream replaces any existing ambient moisture from the gap between the top wafer and the bottom wafer.

A wafer bonding structure, the structure comprising:

• a top wafer on a top bonding framework of a top platform, the top bonding framework including a first plurality of outlet holes and a second plurality of outlet holes around a periphery of the top bonding framework;
• and
• a bottom wafer on a bottom bonding framework of a bottom platform, the bottom bonding framework including a plurality of inlet holes around a periphery of the bottom bonding framework;
• wherein the top platform is in an overlapping relation to the bottom platform.