Patent ID: 7439163

Claim:
A method for fabricating a fluid injection device, comprising: providing a substrate; forming a patterned sacrificial layer on the substrate; forming a patterned first structural layer on the substrate covering the sacrificial layer; forming at least one fluid actuator on the structural layer; forming a first passivation layer on the first structural covering the at least one fluid actuator; conformably forming an under bump metal (UBM) layer on the first passivation layer; forming a patterned first photoresist at a predetermined nozzle site and contact opening site exposing the UBM layer; forming a second structural layer on the UBM layer; forming an etching protective layer on the second structural layer; removing the first photoresist creating an opening at the nozzle site expositing the UBM layer; removing the UBM layer in the opening; removing a portion of the bottom of the substrate, thereby creating a fluid channel in the substrate and exposing the sacrificial layer; removing the sacrificial layer to form a fluid chamber; and sequentially etching the passivation layer and the first structural layer to create a nozzle adjacent to the fluid actuator and communicating with the fluid chamber.