Use of Novel Hydrofluorocarbon and Iodofluorocarbon Chemistries for a High Aspect Ratio Via Etch in a High Density Plasma Etch Tool

Abstract

This paper presents the results of an effort to test several novel chemistries for use as replacements for perfluoro‐compounds in dielectric etch processes. Chemistries belonging to the hydrofluorocarbon and iodofluorocarbon families, namely, 2H‐heptafluoropropane , iodotrifluoromethane , 1‐iodoheptafluoropropane , and 2‐iodoheptafluoropropane , were tested in an Applied Materials Centura 5300 HDP etch tool, using a high aspect ratio silicon dioxide via etch application as the test vehicle. Designed experiment methodology was used in the evaluation. Effluent was analyzed using Fourier transform infrared spectroscopy and quadrupole mass spectrometry. The performance of the alternative etchants in a high aspect ratio via etch process was compared to that of a standard chemistry on the Centura 5300 etch tool. Significant reductions in global warming emissions, relative to a perfluorinated baseline process, were found to be attainable with the alternative chemistries.