Reactive Ion Etched II-VI Quantum Dots: Dependence of Etched Profile on Pattern Geometry

Abstract

The profiles of etched quantum dots are affected by both the geometrical pattern in which the dots are arranged and by the etching conditions. The dots were made by reactive ion etching (RIE) of ZnTe in a mixture of CH4 and H2. In an uniform array of dots, the degree of undercut of the profile increases with the dot spacing, and is proportional to the etched area. When one dot is surrounded by a clearing with no dots, the degree of undercut of the profile is proportional to the radius of the clearing. The addition of a small amount of O2 was found to be effective in controlling the undercut. Using these techniques, it is now possible to create high density arrays of vertical quantum dots in II-VI materials.