Nano-Imprint Lithography (NIL) is considered a promising alternative to optical lithography for technology nodes at
22nm hp and beyond. Compared to other advanced and complex lithography methods, NIL processing is simple and
inexpensive making it a widely accepted technology for pattern media and a potential cost effective alternative for
CMOS applications. During the NIL process, the template comes into direct contact with the resist on the substrate and
consequently template cleanliness plays a decisive role in imprinted substrate quality. Furthermore, if the template has
any form of a defect such as resist residue, stains, particles, surface scratches, chipping and bumping etc. it can lead to
poor quality imprints, low yield and throughput decreases.
The latest ITRS roadmap has stringent CD, CD uniformity, surface roughness and defect control requirements for NIL
templates. Any template cleaning process that is adopted must be able to remove defects while maintaining the critical
parameters outlined by the ITRS. Aggressive chemistries (such as NH4OH or SC1 (NH4OH+H2O2+DI) and strong
physical force treatments (such as MegaSonic & Binary Sprays) may cause damage to the template if not optimized.
This paper presents the cleaning chemical effects on template surface roughness and CD at varying concentrations. The
effect of physical force cleaning on fragile and sensitive pattern features is also presented. Particle & imprint resist
removal efficacy at different process conditions is compared.