6.1 Introduction to Etching of SiC

G.L. Harris
June 1995

The successful fabrication of SiC based devices cannot be realized without reliable etching and cleaning processes for this material. The purpose of this Chapter is to review the developments and methods of etching silicon carbide for device applications. The term etching is used to describe the processes by which SiC material can be removed. It also includes chemical machining of a semiconductor as part of the fabrication process, as well as defect delineation.

The mechanical removal of SiC can be carried out using boron carbide and/or diamond paste using a diamond coated lapping cloth. Mesh sizes of the diamond and boron carbide range from submicron to over 10 microns depending on the stage of lapping. Under normal conditions a large mesh size is used first followed by a much smaller mesh size. The lapping rates vary depending on the applied pressure. The mechanical polishing does introduce some surface damage and that damage can be removed by etching or oxidation and removal of the oxide layer.

In this Chapter, we will review the chemical, ion sputtering, plasma-assisted and reactive ion etching techniques for SiC. These processes can be used in fabricating SiC devices.

6.2 Chemical Etching of SiC

G.L. Harris
September 1994

Silicon carbide is a highly refractory material and chemical etching can only be achieved successfully with the aid of hot gases and hot molten salt etches. At present, no known aqueous (acid, neutral or basic) solution attacks SiC at...