Making 50 nm transistors with 248 nm lithography

Using a novel phase-shift mask, 50 nm resolution has been achieved with conventional 248 nm lithography. The addition of so-called scattering bars enables within-die control of linewidths from 250 to 50 nm. Using 200 nm thick resist layers combined with hard mask processing, transistors with gate-lengths down to 50 nm have been fabricated. Well controlled device performance is achieved by optimizing offset spacers and pocket implants.