DRIE

Samuel Queste, Gwenn Ulliac, Jean-Claude Jeannot and Chantal Khan Malek
Institute FEMTO-ST/Dpt. MN2S, CNRS UMR 6174, 32 Av. de l’Observatoire, 25044 Besançon, FRANCE

Abstract

High speed directional etching of non conventional materials is still insufficiently developed for producing high aspect ratio microstructures. Compared to deep silicon etching, the plasma etching of these materials has suffered from limitations in achievable depth, aspect ratio, verticality and smoothness of surfaces. Inductively coupled plasma (ICP) reactive ion etching (RIE) of quartz crystal, lithium niobate and glass was conducted using fluorine and fluorocarbon based plasma-chemical etching processes. Optimization of etched depth, verticality of the walls, etch rate, etch selectivity towards the etch mask, and surface smoothness was investigated and compared to results of the literature. Deep etching with nearly vertical walls was successfully demonstrated for all three materials.