Method of making a microfluid ejection head structure

A method of making a micro-fluid ejection head structure, the method comprising:

• forming a plurality of fluid supply slots in a semiconductor substrate wafer having a device surface thereon;
• applying a removable mandrel material to the device surface of the semiconductor substrate wafer, wherein the mandrel material is shaped to provide fluid chamber and fluid channel locations on the semiconductor substrate wafer;
• dry-spraying the shaped mandrel material and the device surface of the substrate wafer with a micro machinable material in a carrier fluid to provide a spray-coated layer on the shaped mandrel and device surface of the substrate wafer, the spray-coated layer having a thickness ranging from about 10 to about 80 microns;
• forming a plurality of nozzle holes in the spray-coated layer;
• and
• removing the shaped mandrel material from the device surface of the substrate wafer to provide fluid chambers and fluid channels in the spray-coated layer.