Deep Reactive Ion Etching of Lead Zirconate Titanate Using Sulfur Hexafluoride Gas

A deep reactive ion etching (RIE) technique that uses sulfur hexafluoride (SF 6 ) gas has been developed for lead zirconate titanate (Pb(Zr,Ti)O 3 , PZT) three-dimensional microfabrication from PZT ceramic blocks. The etching was performed by using an inductively coupled plasma that was generated in a narrow-gap vacuum chamber. The etch depth was 70 μm with a maximum etch rate of 0.3 μm/min and a selectivity of PZT to the electroplated nickel mask of >35:1. The sidewalls of the PZT structures were tapered, with base angles of -75°. Both positive RIE lag and unexpected ultrafine-slit etching phenomena were observed.