Patent ID: 7152958

Claim:
An ink jet printhead comprising: an elongate substrate; a plurality of nozzles formed on a surface of the substrate; at least one nozzle plate spaced apart from the substrate surface, wherein each nozzle comprises: one nozzle chamber corresponding to each of the nozzles respectively, said nozzle chamber comprising a roof, defined by at least part of the nozzle plate, and walls extending therefrom to the substrate surface, said nozzle chamber having one opening in its roof, said opening defining an ink ejection aperture for the nozzle chamber; and at least one heater element corresponding to each of the nozzles respectively, said heater element being configured for thermal contact with a bubble forming liquid, to heat at least part of the bubble forming liquid to a temperature above its boiling point to form a gas bubble to eject a drop of the bubble forming liquid through the ink ejection aperture corresponding to that heater element, wherein said at least one nozzle plate and said walls are fabricated by a process of: depositing sacrificial material onto the substrate surface and heater element; defining openings in the sacrificial material for deposition of wall material; co-forming said at least one nozzle plate and said walls by chemical vapor deposition (CVD) of silicon nitride, silicon oxide or silicon oxi-nitride onto the sacrificial material and into the openings defined in the sacrificial material; defining the nozzle openings in the nozzle plate; and removing the sacrificial material.