Experimental realization of sub-micron patterning using counter-propagating interfering lightsheets (iCLASS)

A light-sheet-based plane-selective sub-micron patterning technique is proposed to fabricate 1D sub-micron patterns with specificity and selectivity. The proposed technique is termed as, interfering coherent light-sheet assisted structure synthesis (iCLASS). The technique uses specialized 2π optical illumination geometry to expose the photoresist film. Counter-propagating light sheets (satisfying phase-matching condition) produce 1D interference pattern with feature size below the diffraction limit. A conventional S1813 photoresist coated on a cleaned glass substrate is exposed to the light-sheets pattern and subsequently, the photoresist film is developed to imprint the sub-micron pattern. AFM study confirms imprinted 1D pattern with a periodicity and feature-size of approximately, λ/2. Analysis show that the light-dose interaction-time (τexp, τdev) plays crucial role in determining the periodicity of 1D sub-micron pattern.