Formation of three-dimensional structures in the silicon carbide substrates by plasma-chemical etching

Abstract

A survey dealing with the technology of the formation of three-dimensional structures in silicon carbide substrates is presented. As for technology, this problem can be solved by variational ion-stimulated plasma-chemical etching, and most successfully by the source of inductively coupled plasma (ICP). Silicon carbide consists of silicon and carbon that form volatile fluorides in the reaction with fluorine. The etching reaction takes place in the interaction of silicon and carbon with reactive intermediates and fluorine ions. That is why the fluorine-containing gas, sulfur hexafluoride SF₆ in most cases (often with an admixture of oxygen and sometimes argon), is used for the plasma-chemical etching of silicon carbide. The materials that do not react with fluorine are applied for masking during the plasma-chemical etching of silicon carbide. The films of metals such as Cu, Al, and Ni are mainly used and silicon oxide is less used. The formation of through-holes in these substrates followed by the metallization of the holes is a particularly important technological concept related to the plasma-chemical etching of the SiC substrates with the deposited GaN epitaxial layers. Examples of the use of ICP sources for the formation of micro- and nanosize three-dimensional structures in silicon carbide are given. Among them, the formation of the through-holes in the substrates of silicon carbide with epitaxial layers of gallium nitride is discussed.