The stripping method of high-dose ion-implanted resist layers was studied on the basis of the chemical structure of carbonized layers formed by ion implantation and that of residues remaining on the wafer surface after O2 plasma ashing. The chemical structure of the carbonized layer was observed with solid NMR and that of residues was analyzed with XPS. A decrease in the etching rate of the high-dose ion-implanted resist was caused by carbonization of polymers of the resist. Residues were mainly formed during O2 plasma ashing by chemical reaction between oxygen and implanted species, i.e., the main component of residues was oxide of the implanted species. On the basis of these results, to remove the high dose ion implanted resist without damage, we developed a two-step ashing process which was composed of H2 RIE and downstream ashing, and achieved the purpose.
The critical amount of nitrogen atoms at the interface, above which the roughness of the oxynitride/Si(100) interface increases, was studied using noncontact-mode atomic force microscopy and X-ray photoelectron spectroscopy. The interface roughness was found to increase upon increasing the amount of nitrogen atoms at and near the interface if the amount of nitrogen atoms is greater than 0.37 monolayers. This increase in interface roughness was found to be reflected in an increase in surface roughness of almost the same amount.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.