Inductively coupled plasmas (ICP) etching of PZT thin films for fabricating optical waveguide with photoresist/aluminum bilayer masking

Waveguide morphology, as well as etched surface, is one of the most important factors deciding the performance of optical waveguide devices. In this work, we present a combination using photoresist/aluminum bilayer mask for the ICP etching of PZT (Pb(Zr1-xTix)O3) thin films. The etching results of PZT thin films with different etching methods and various etching conditions were investigated. It was found that using ICP in 30/10sccm CHF3/Ar mixture and 3Pa could help reduce the defects and contaminations on the etched surface of PZT thin films. Compared with 250W/60W dual- electrode ICP etching, a more vertical etch profile of PZT waveguide could be obtained through 100W single-electrode ICP etching under the optimal conditions.

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