Photoresist imaging and development for enhanced nozzle plate adhesion

A method for making a fluid jet ejection head comprising:

• providing a silicon substrate having a device surface containing at least one array of fluid ejectors thereon;
• laminating or spin-coating a photoresist material onto the device surface of the silicon substrate;
• exposing the photoresist material to actinic radiation through a mask to provide a flow feature layer, wherein the mask contains opaque areas defining a plurality of fluid flow channels and fluid chambers in the photoresist material and masked areas adjacent to the plurality of fluid flow channels and fluid chambers, wherein the mask used in the masked areas adjacent to the plurality of fluid flow channels and fluid chambers contains a plurality of opaque geometric particles having a size ranging from about 1 to about 5 microns, wherein the opaque geometric particles are effective to provide a roughened surface area in the masked areas adjacent to the plurality of fluid flow channels and fluid chambers for increased adhesion between a developed surface of the photoresist material and a nozzle plate attached to the roughened surface area of the flow feature layer;
• etching a fluid supply via in the silicon substrate;
• developing the photoresist material to provide the plurality of fluid flow channels and fluid chambers therein and the roughened surface area that provides improved surface adhesion characteristics;
• and
• attaching a nozzle plate to the roughened surface area of the flow feature layer.