Novel scanning immersion lithography (SIL) for 3D microfabrication

We propose the first time combining the merit of scanning and immersion lithography to fabricate 3D microstructure in this study. Via applying a matching liquid to reduce the diffraction error, the gap between the mask/resist becomes more tolerable. In addition, the liquid also act as a lubricant and a buffer for smooth movement of the mask/substrate. These advantages will benefit the performance of scanning lithography technique. The experimental results show that the large-area, 3D microstructure with excellent surface quality (R_avg<10 nm) can be successively fabricated based on this method. Besides, 3D microstructures with various geometries and functionalities can be generated by altering the shape of the mask pattern, or changing the scanning directions. The proposed SIL technique seems to be a promising way for fabricating 3D microstructure for optical applications.