Patent ID: 8450141

Claim:
A process for fabricating back contacts for a photovoltaic cell device, the device comprising a wafer having a back surface, one or more emitter regions, one or more emitter contacts, and one or more base contacts, the process comprising the steps of: depositing a first passivation layer on the back surface of the wafer; depositing an n-type or p-type emitter layer on the passivation layer, the emitter layer comprising the one or more emitter regions; depositing a metal layer on the emitter layer; laser firing selected areas of the metal layer to form the one or more base contacts; laser cutting the metal layer to pattern the metal layer and create at least one isolation region between the one or more emitter contacts and the one or more base contacts; and applying a stream of reactive gas to form a second passivation layer in the isolation region while laser cutting the metal layer.