Effects of bias RF pulsing plasma in implant layer BARC etch process

ArF photoresist (PR) and BARC together are being adopted as a LDD (lightly doped drain) implantation blocking layer for applications with smaller CD and larger aspect ratio. BARC open process is followed by a plasma etch process. In this work, the BARC open etch process was performed using a commercial etch system equipped with bias pulsed plasma. The effects of continuous wave (CW) and bias RF pulsed plasma on the BARC open process were studied, and the mechanism was analyzed. Bias pulsed plasma was shown to be effective in improving PR remaining and PR/BARC profile.