A process for forming inkjet nozzle devices on a frontside surface of a wafer substrate. The process includes the steps of: (i) providing the wafer substrate having a plurality of etched holes defined in the frontside surface, each etched hole being filled with first and second polymers such that the second polymer is coplanar with the frontside surface; (ii) forming the inkjet nozzle devices on the frontside surface using MEMS fabrication steps; and (iii) removing the first and second polymers via oxidative ashing, wherein first and second polymers are different.