Ar Ion Implantation into Resist for Etching Resistance Improvement

摘要

Argon (Ar) ion implantation into resist pattern was investigated and the remarkable improvement of the etching resistance was confirmed on various films such as tungsten, aluminum copper, silicon oxide and silicon nitride. The possibility to make resist thickness thinner was proven. Ion dose more than lE15/cm~2 was necessary to obtain a sufficient effect, so that shrinking of resist thickness and pattern width occurred simultaneously. The dependence of pattern shrinking on the line width was observed. Line width uniformity within a wafer was improved because of high etching resistance by ion implantation process. Line edge roughness (LER) of resist pattern was also reduced by ion implantation and smooth etched pattern could be formed. Although same effects were obtained for ArF resist, the shrinkage of ArF resist after ion implantation was more than that of KrF resists. The improvements in etching resistance and critical dimension (CD) control will be discussed in this article.