Reactive ion beam etching of InP with Cl2

Abstract

Reactive ion beam etching of InP with chlorine gas under oblique angles of incidence is reported. This process offers the important advantage of edge profile control. The etch rate is strongly dependent upon the ion energy, manifesting a plateau approaching 0.2 μm/min for a chlorine beam of less than 1 keV. At normal incidence of the ion beam the walls are sloped outward by about 17°. A mesa-type structure with straight, smooth vertical walls has been fabricated by spinning the substrate under oblique ion beam incidence.