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.