Electrical validation of the integration of 193i and DSA for sub-20nm metal cut patterning

The progress of using DSA for metal cut to achieve sub-20nm tip-to-tip (t2t) critical dimension (CD) is reported. Small and uniform t2t CD is very challenging due to lithographic limitation but holds the key to backend-of-the-line (BEOL) scaling. An integration scheme is demonstrated that allows the combination of design flexibility and fine, rectified local CD uniformity (LCDU). Functional electrical testable Via-Chain structure is fabricated to verify the integrity of the proposed method. Through the analysis of the observed failure modes, the process is further improved. By validating DSA for such an important patterning element as metal cut, the DSA maturity can be further advanced and hopefully move DSA closer to HVM adoption.