화학공학소재연구정보센터
Journal of the Electrochemical Society, Vol.148, No.3, G141-G149, 2001
Evaluation of oxalyl fluoride for a dielectric etch application in an inductively coupled plasma etch tool
The goal of the work presented in this article was to provide a preliminary screening for a novel fluorinated compound, oxalyl fluoride, C2O2F2 (F-(C=O)-(C=O)-F), as a potential replacement for perfluorocompounds in dielectric etch applications. Both process and emissions data were collected and the results were compared to those provided by a process utilizing a standard perfluorinated etch chemistry (C2F6). In this evaluation, oxalyl fluoride produced very low quantities of global warming compounds under the conditions in which it was tested, as compared to the C2F6 process. A preliminary evaluation of the compound's process performance wa's also carried out. Patterned tetraethoxysilane-deposited silicon oxide masked with deep UV photoresist having 0.6, 0.45, and 0.35 mum via hole features was used as the test vehicle. Although C2O2F2 was capable of etching silicon dioxide, low oxide etch rate and poor selectivity to the mask layer were observed. Finally, in addition to the experimental work performed, a set of ab initio quantum chemical calculations was undertaken to obtain enthalpies of dissociation for each of the bonds in the oxalyl fluoride molecule in order to better understand its dissociation pathways in plasma environments. (C) 2001 The Electrochemical Society. All rights reserved.