Method of fabricating micro-electromechanical inkjet nozzle

1. A method of fabricating a micro-electromechanical inkjet nozzle on a wafer substrate, the nozzle comprising a nozzle chamber having an aperture, an actuator positioned in the nozzle chamber for ejecting ink through the aperture, and control circuitry for controlling the actuator, the control circuitry being formed on the substrate, the method comprising the steps of:

(a) carrying out an integrated circuit fabrication process on the wafer to form the control circuitry;

(b) depositing first sacrificial material on the wafer;

(c) forming the actuator on the first sacrificial layer such that the actuator electrically connects with the control circuitry;

(d) depositing second sacrificial material over the actuator;

(e) defining openings in the second sacrificial material, the openings being complementary with chamber sidewalls;

(f) depositing roof material over the second sacrificial material and into the openings;

(g) defining an aperture in the roof material; and

(h) removing the first and second sacrificial materials.

2. The method of claim 1 , in which the step of carrying out the integrated circuit fabrication process comprises the step of carrying out a CMOS process.

3. The method of claim 1 , wherein the actuator is a thermal actuator.

4. The method of claim 1 , wherein the roof material is deposited by PECVD.

5. The method of claim 1 , wherein an ink supply channel is back-etched to the nozzle prior to removing the sacrificial material.

6. The method of claim 1 , wherein a plurality of nozzles are formed on the wafer substrate.

7. The method of claim 1 , which forms part of a printhead fabrication process.