By Cameron Chai
At the SPIE Advanced Lithography conference to be conducted in San Jose, California, Imec will announce the successful deployment of first-of-its-kind 300 mm fab-compatible directed self-assembly (DSA) process line in its 300 mm cleanroom fab.
14 nm polystyrene lines on 28 nm pitch after PMMA removal fabricated by DSA using 193 nm immersion based 84 nm pitch pre-pattern (left) and demonstration of the ability to repair a 200 nm gap in the pre-pattern (right).
Imec, in partnership with Tokyo Electron, AZ Electronic Materials and the University of Wisconsin, had upgraded a DSA process from an academic lab-scale to a fab-compatible flow, with an aim to tackle the critical bottlenecks in upgrading the academic lab-scale DSA to a mass-production environment.
DSA is a promising alternative patterning technology that extends optical lithography further than its existing limits. It allows frequency multiplication by utilizing block copolymers. DSA together with a suitable pre-pattern that controls the orientation for patterning is capable of decreasing the final printed structure’s pitch. In addition, it is capable of repairing uniformity and defects in the original print. The combination of this repair feature and EUV lithography is highly useful.
Imec now has the entire on-site toolset, which includes a uniquely configured and dedicated DSA coater/developer produced by TEL with proprietary pattern transfer capabilities, the metrology toolkit such as DSA defect inspection, and deployed DSA materials in gallon-size capacities, all-under-one-roof in the 300 mm cleanroom fab.
With well-recognized 193 nm (immersion and dry), 248 nm and EUV lithography tools on site, Imec is now capable of investigating DSA defectivity with focus on improving DSA’s pattern reliability for semiconductor fab specifications. In addition, Imec intends to further develop the DSA repair capabilities together with EUV lithography in order to extend EUV lithography to manufacturing level.