Comparison of the Etch Mask Selectivity of Nickel and Copper for a Deep, Anisotropic Plasma Etching Process of Silicon Carbide (SiC). (17th January 2018)

• Record Type: Journal Article
• Authors: Ozgur, Mehmet; Pedersen, Michael; Huff, Michael
• Is Part Of: ECS journal of solid state science and technology. Volume 7:Number 2(2018)
• Page Start: P55
• Page End: P59
• Publication Date: 2018-01-17
• Subjects: hard mask selectivity -- ICP etching -- SiC; Solid state chemistry -- Periodicals; Electronics -- Materials -- Periodicals; Electrochemistry -- Periodicals; 541.0421
• DOI: 10.1149/2.0121802jss
• Languages: English
• ISSNs: 2162-8777

Abstract

Abstract : This paper reports research performed on comparing the etch mask selectivity of two different hard mask material layers, specifically nickel and copper, used for deep, anisotropic plasma etching of Silicon Carbide (SiC) substrates. Hard masks are required when performing deep etches into SiC given the extreme inertness of SiC combined with the high ion energies needed for the plasma etching of this material. Using a recently developed deep, highly-anisotropic inductively-coupled plasma process, we performed etches of SiC substrates with patterned hard masks composed of different types of materials to measure and compare their mask selectivity. The mask selectivity is important since it relates to how thick the hard mask layers must be in order to survive the required etch time to obtain a desired etch depth, and the thickness of the patterned hard mask layer has a direct impact on the resultant dimensional tolerances that can be obtained from the etch process. Using a deep, highly-anisotropic etch process we measured that the mask selectivity of nickel to be approximately 25 and that of copper to be 163. The capability to etch highly-anisotropic deep features into SiC using hard mask material layers has important implications for a number of applications in MEMS and microelectronics.