A Gate-Dielectric-Last Process via Photosolidification of Liquid Resin

A gate-dielectric-last process is demonstrated on an independent double-gate FinFET as a test vehicle. After the source/drain (S/D) process, the dummy gate dielectric is selectively replaced with a liquid monomer that can be cured by ultraviolet treatment. The present scheme provides the benefits from both gate-first and gate-last processes. The replacement of the gate dielectric is a minor modification of the baseline of the gate-first process. Compared to the gate-last process, the gate dielectric last does not introduce process complexity or alter the design rule. As the gate dielectric is formed after the S/D, the thermal-budget issue can be mitigated.