Effects of Additive Gases on Ag Etching using Inductively Coupled Cl2-based Plasmas

In this study, the eects of additive gases on the Ag etching were investigated using Cl2-based inductively coupled plasmas. When Cl2-based gases were used to etch Ag lms, due to the formation of involatile etch by-products, thick etch reaction products were remained. However, these etch by- products could be removed during the photoreist wet stripping process, therefore, various Ag removal rates could be obtained depending on the process conditions. When Cl2 was used with N2 and O2, higher Ag removal rates than those by pure Cl2 could be obtained. These results are interpreted as the increase of Cl radical due to the enhancement of the dissociation of Cl2 gas when N2 was added to Cl2 and the formations of more porous and reactive etch reaction products when O2 was added to Cl2. Therefore, Ag lms removal rates showed the maximum at 50 %Cl2/50 %N2 for Cl2/N2 and also at 50 %Cl2/50 %O2 for Cl2/O2. However, when Cl2 was used with Ar, Ag removal rates was not increased with the addition of Ar possibly due to the formation of a dense etch by-product and a low sputter yield of the formed etch by-product. KCI Citation Count: 3