Abstract: A plasma treatment is utilized prior to a conventional lift-off process to increase the hydrophilic characteristics of the surface of the sacrificial metal over the photoresist and minimize its ability to redeposit on the wafer surface. Highly-energized atoms (or molecules) in the plasma interact with the surface atoms of the metal, creating a temporary hydrophilic condition at the surface. This increased wettability of the metal layer surface thus minimizes the probability that subsequently removed thin film metal will be able to bond with the wafer surface. The metal layer may comprise a typical stack of Ti/Pt/Au, and the plasma treatment may use an O2-based plasma or a CF4-based plasma, among others.

Abstract: A plasma treatment is utilized prior to a conventional lift-off process to increase the hydrophilic characteristics of the surface of the sacrificial metal over the photoresist and minimize its ability to redeposit on the wafer surface. Highly-energized atoms (or molecules) in the plasma interact with the surface atoms of the metal, creating a temporary hydrophilic condition at the surface. This increased wettability of the metal layer surface thus minimizes the probability that subsequently removed thin film metal will be able to bond with the wafer surface. The metal layer may comprise a typical stack of Ti/Pt/Au, and the plasma treatment may use an O2-based plasma or a CF4-based plasma, among others.