Metal liftoff in advanced immersion tank with multidirection jet fluid and multi-frequency ultrasonic energy
Metal Liftoff (MLO) is most commonly used in the patterning of metal films for interconnects in semiconductor wafer fabrication. In MLO process, a sacrificial photoresist layer is printed using an inverse mask pattern. The metal pattern is created by blanket coating the photoresist pattern with metal or oxide and washing away the sacrificial layer. Any material which was deposited on the sacrificial layer is removed, while any material which was in direct contact with the substrate remains. The key to successful lift-off is the ability to ensure a distinct break between the layer material deposited on top of the stencil and the layer material deposited on top of the wafer.
