Angular Dependence of Si3N4 Etching in C4F6/CH2F2/O2/Ar Plasmas. Issue 12 (7th November 2017)

• Record Type: Journal Article
• Authors: Kim, Jun-Hyun; Cho, Sung-Woon; Kim, Chang-Koo
• Is Part Of: Chemical engineering & technology. Volume 40:Issue 12(2017)
• Page Start: 2251
• Page End: 2256
• Publication Date: 2017-11-07
• Subjects: Angular dependence -- Etch yields -- Fluorocarbon films -- Physical sputtering -- Si3N4 etching; Chemical engineering -- Periodicals; Chemical processes -- Periodicals; 660.05
• DOI: 10.1002/ceat.201700126
• Languages: English
• ISSNs: 0930-7516

Abstract

Abstract: The dependence of Si3 N4 etching on ion‐incident angles is investigated at various CH2 F2 flow rates in C4 F6 /CH2 F2 /O2 /Ar plasmas. The normalized etch yield (NEY) curves for Si3 N4 imply that physical sputtering is a major contributor to Si3 N4 etching. An increase in the amount of CH2 F2 in the plasma produces thicker and more etch‐resistant fluorocarbon films. Systematic analyses on deposition and etching of the passively deposited fluorocarbon films on Si3 N4 in a C4 F6 /CH2 F2 /O2 /Ar plasma show that the normalized deposition rate of the fluorocarbon film is nearly the same and unaffected by the CH2 F2 flow rate while etching of fluorocarbon films is similar to etching of Si3 N4, thus, etching of the fluorocarbon film, rather than its deposition, limits Si3 N4 etching in C4 F6 /CH2 F2 /O2 /Ar plasmas. Abstract : In order to predict and control etch selectivities and profiles, it is essential to understand the angular dependence of the Si3 N4 etch rate. The normalized etch yield (NEY) is obtained for a Si3 N4 etching in C4 F6 /CH2 F2 /O2 /Ar plasmas. The NEY curves revealed that physical sputtering is a major contributor to Si3 N4 etching in C4 F6 /CH2 F2 /O2 /Ar plasmas.