Method of fabricating inkjet nozzle comprising suspended actuator

1. A method of fabricaring inkjet nozzles on a substrate, each nozzle comprising a nozzle chamber and an actuator suspended in the nozzle chamber, each nozzle chamber comprising a roof having a nozzle aperture defined therein and sidewalls extending from the roof to the substrate, the method comprising the steps of:

(a) depositing a layer of first sacrificial photoresist onto the substrate;

(b) defining actuator scaffolds in the first sacrificial photoresist;

(c) depositing actuator material onto the actuator scaffolds;

(d) etching the actuator material to define actuators;

(e) depositing a layer of second sacrificial photoresist to cover the actuators;

(f) defining openings in the second sacrificial photoresist, the openings being complementary to chamber sidewalls;

(g) depositing roof material onto the second sacrificial photoresist and into the openings, thereby forming the roof and sidewalls of each chamber;

(h) etching nozzle apertures through each roof; and

(i) removing the first and second sacrificial photoresist exposed through the nozzle apertures.

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

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

4. The method of claim 1 , wherein the actuator is a bubble-fanning heater element.

5. The method of claim 4 , wherein etching the actuator material includes defining a void space in a central portion of the actuator.

6. The method of claim 4 , wherein the actuator material is deposited onto heater contacts on either side of each scaffold at the sane time as being deposited onto the scaffold, thereby forming an electrical connection between the heater element and the heater contacts.

7. The method of claim 1 , wherein each chamber roof forms part of a nozzle plate spanning a plurality of nozzles.

8. The method of claim 1 , wherein the roof material is silicon nitride.

9. The method of claim 1 , wherein the roof material is deposited by plasma enhanced chemical vapour deposition (PECVD).

10. The method of claim 1 , wherein each nozzle aperture has a respective nozzle rim.

11. The method of claim 10 , wherein nozzles rims are etched into each roof prior to etching nozzle apertures through each roof.

12. The method of claim 1 , wherein ink supply channels are back-etched to the nozzles prior to removing the sacrificial photoresist.

13. The method of claim 1 , wherein the sacrificial photoresist is removed by plasma ashing.