Investigation of the polymer systems for ArF resists

Various resists, which consisted of polymer systems, such as methacrylate, acrylate and cycloolefin/maleic anhydride (COMA), were investigated in the viewpoint of etching resistance, lithographic performance and shelf life. The oxide etching rate was in order of acrylate < methacrylate << COMA. The surface roughness of the acrylate type resist after oxide etching was the smallest among all samples. The methacrylate type resist showed high resolution capability as a line and space resist. On the other hand, pattern collapse was observed in the acrylate type resist, and low resolution was shown in the COMA type resist because of the large resist thickness loss. In the case of contacts, the acrylate type resist showed better linearity. The sensitivity of the acrylate and methacrylate type resists kept at room temperature did not changed in 20 days, while the sensitivity of the COMA type resist changed. It was found that the methacrylate type resist was the most suitable as a line and space resist and the acrylate type resist was the most promising as a contact hole resist.