Process for fabricating microactuator membranes of piezoelectric inkjet print head using multi-step deep reactive ion etching process

As part of an effort to develop piezoelectric inkjet print head (PIPH), a process for fabricating its Si-cups and actuator membranes of multi-layered structures was investigated. The manufacture of this device was enabled by the use of deep reactive ion etching (DRIE). Based on that, multi-step DRIE process was proposed to etch the multi-layered actuator membranes on silicon on insulator wafers. Due to the appropriate parameters of the etching process, undesirable effects, such as Si grasses, notching effect of Si-cups and the bowing formation on the sidewalls, were also avoided. The way to eliminate the over-etching of SiO2 membranes by controlling the appropriate platen power and process duration simultaneously was also presented. High quality PIPH actuator membranes were finally obtained, making great contributes to the successful inkjet test.