Residue‐Free Reactive Ion Etching of Silicon Carbide in Fluorinated Plasmas: II .

We have previously reported the residue‐free reactive ion etching (RIE) of in /, /, /, and/ mixtures with additive. The minimum concentration for residue prevention was found to vary with the content of each gas plasma and from gas to gas. In this paper, we report on the reactive ion etching of in the same gas plasmas. The etch rate and etched surface morphology under different etching conditions are presented. A similar pattern of minimum concentrations for the residue‐free RIE of is obtained. This indicates that the process involving additive in the fluorinated plasma could be applied to other polytypes. A residue‐free etching surface can be obtained without the additive only in pure plasma. Other plasma conditions do need various levels of concentration in the plasma to obtain a clean etched surface. In both 3C‐ and the etch rate decreases as the concentration increases. No etching undercut was found for with Al as etching mask. A graphite sheet covering the powered electrode also produced residue‐free RIE but suffers from undesirable side effects. A comparison of minimum levels for residue‐free etching of 3C‐ and in different plasmas is discussed.