DAMAGE TO SI SUBSTRATES DURING SIO2 ETCHING - A COMPARISON OF REACTIVE ION ETCHING AND MAGNETRON-ENHANCED REACTIVE ION ETCHING

The damage and contamination effects present in silicon substrates from both reactive ion etching -and magnetron-enhanced reactive ion etching of SiO2 have been examined for various overetch percentages using spectroscopic ellipsometry (SE) and -secondary ion mass spectroscopy (SIMS). The former method has shown that the thickness of the etch-induced heavy damage layer in silicon decreases, but its damage density increases with magnetic field. In addition, a thinner fluorocarbon residue layer was detected by both SE and SIMS -on the samples etched in the presence of a magnetic field. The high temperature annealing behavior of silicon surfaces after UV/O2 removal of this polymer layer was also compared for samples etched with and without the presence of a magnetic field. Almost complete surface recovery was observed for the samples etched with the presence of a magnetic field as a result of a 15 min anneal at 600-degrees-C.