Youichi Ohsawa

Inactivation technology for pitch doubling lithography

We propose novel inactivation technologies which improve resolution. Base generators have been developed, which inactivate acid by thermal treatment or exposure. This thermal inactivation technology realizes simple litho-inactivation-litho-etch (LILE) process with good fidelity. After 1st patterning, acid is inactivated by amine released from the thermal base generator under low temperature baking of less than 150°C. Just adding one simple low temperature bake process, LILE has two advantages; i) keeping high throughput, and ii) avoidance of pattern deformation. 32nm line and space (l&s) pattern is successfully delineated. The inactivation technology has been expanded to frequency doubling patterning. Photo base generator (PBG) is used to inactivate acid generated by exposure. Acid concentration in both of low and high exposed area is precisely controlled by base generation efficiency of PBG. The dual tone resist successfully delineates 32.5nm l&s pattern using 65nm l&s mask patterns with single exposure.