Remote plasma processing for reduction of CuOx before damascene electroplating

Copper seeded interconnects will oxidize over time in cleanroom environments by reacting with oxygen and water in the ambient air. Copper oxide formation on current and future interconnect seed layers can result in void formation, adhesion issues, and non-uniform plating. Here, we describe an H₂ plasma treatment process that can be used to reduce copper oxides to copper metal before damascene electroplating. This process can lower seed resistance, improve fill characteristics, and potentially lead to improved yield on 300 mm wafers.