Deep Reactive Ion Etching of Lithium Niobate by Using Low-Frequency Bias

Abstract

Lithium niobate (LN) etching has been demonstrated with an electron cyclotron resonance (ECR) plasma and low-frequency bias. The etching was studied by using Ar, BCl3 and SF6 gases. The etch rates of BCl3 and SF6 are about 3.8 and 4.6 times higher than that of Ar, respectively. The highest etch rate (220 nm/min) was obtained under the condition of SF6 plasma and 1 MHz bias. The etching method which can fabricate micro-trenches with high-aspect ratio and smooth surfaces has been achieved.