Directional reactive ion etching at oblique angles

Directional reactive ion etching (RIE) at oblique angles is possible using a simple grid‐covered structure (Faraday cage) in conventional parallel‐plate sputter etching equipment. Oblique‐angle etching, as is possible in any ion‐beam system, has been demonstrated using the etchant ions from CHF3 gas on a fused‐silica substrate. The first detailed measurements of the angular etch dependence of RIE show a strong similarity to those of an ion‐beam system (no chemical etching).