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

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. (paper)