The effect of a lithium niobate heating on the etching rate in SF6 ICP plasma

Abstract

The effect of substrate temperature on the plasma-chemical etching rate of lithium niobate (LiNbO3) single-crystals in an inductively coupled plasma (ICP) is studied in this paper. we found that the etching rate is a complex function of a substrate temperature with an interval where increases in the temperature lead to a significant growth of the etching rate. comparing the results of LiNbO3 etching in two different gas mixtures (SF6/O2 and SF6/Ar) showed that the etching process in SF6/O2 mixtures provides a higher productivity and a qualitatively better surface roughness. the maximum etching rate achieved during this research was more than 800 nm min−1. The deep linbo3 etching process (more than 113 μm) using an applied high frequency (HF) source with a power of 700 W was implemented, resulting in an etching rate of more than 420 nm min−1.