Fabrication of organic nanoparticles by PRINT: master generation using lithographic and RIE techniques

Abstract

By using PRINT (Particle Replication In Non-wetting Templates), a general soft technique for replication of diverse shapes at the sub-micron level, we have been able to produce organic nano-particles. Lithographic patterning (using 193nm exposure tool) was employed to generate 160nm posts on a 6" Si wafer; the material of the posts being the organic polymer based commercial photoresist. RIE was then performed on the patterned substrate to transfer the geometry to the Si; various aspect ratios of the Si nano-posts were obtained upon etch time variation. PRINT was used to make a mold of the nano-features on the Si wafer and subsequently fabricate cross-linked organic nano-particles by using PEG-diacrylate (PolyEthylene Glycol diacrylate). Such organic nano-matrices would be potentially useful as therapeutic agent carriers, imaging chemical encapsulants and localized drug delivery vehicles.