Bonding method using surface activation plasma treatment

A method of bonding, the method comprising:

• receiving a first wafer in a surface activation plasma (SAP) system, the first wafer comprising a bonding layer disposed over an underlying layer;
• generating a nitrogen plasma configured to activate a surface;
• exposing the bonding layer to the nitrogen plasma to form a surface activated bonding layer comprising nitrogen groups, wherein the nitrogen groups comprise inactive nitrogen termination sites;
• rinsing the surface activated bonding layer with deionized water (DIW), wherein the rinsing converts the surface activated bonding layer to a treated bonding layer comprising hydroxyl groups and the nitrogen groups;
• and
• bonding the treated bonding layer with the nitrogen groups and the hydroxyl groups to a second wafer.

A system for semiconductor processing, the system comprising:

• a vacuum pump coupled to a surface activation plasma (SAP) chamber, the SAP chamber comprising a wafer holder and a top electrode;
• a gas system coupled to the SAP chamber through a gas inlet, the gas system comprising a first precursor gas, a second precursor gas, and a purging gas;
• a temperature control system coupled to the wafer holder;
• an RF power supply electrically coupled to the top electrode;
• and
• a controller coupled to the RF power supply, the vacuum pump, the gas inlet, the gas system, the wafer holder, the SAP chamber, and a memory storing instructions to be executed in the controller, the instructions when executed cause the controller to:
• receive a first wafer on the wafer holder, the first wafer comprising a bonding layer disposed over an underlying layer,
• generate a nitrogen plasma using the gas system and the RF power supply, the nitrogen plasma configured to activate a surface,
• expose the bonding layer to the nitrogen plasma to form a surface activated bonding layer comprising nitrogen groups, wherein the nitrogen groups comprise inactive nitrogen termination sites,
• rinse the surface activated bonding layer with deionized water (DIW), wherein the rinse converts the surface activated bonding layer to a treated bonding layer comprising hydroxyl groups and the nitrogen groups, and
• bond the treated bonding layer with the nitrogen groups and the hydroxyl groups to a second wafer.