Optical Interference Lithography Using Azobenzene-Functionalized Polymers for Micro- and Nanopatterning of Silicon

摘要

Azobenzene-containing polymers (azopolymers) have attracted great interest due to their potential use in various technological applications, including holographic recording, photomechanics, diffractive optics, and micro- and nanopatterning. These applications are brought about by the efficient and reversible photoisomerization of the azobenzene moieties between a rod-like trans-state and a bent cis-state, which is accompanied by various changes in the properties of the material system both at molecular and macroscopic levels. Remarkably, the photoisomerization can give rise to significant surface mass transport phenomena, allowing one-step inscription of high-quality, thermally stable photoinduced surface patterns onto the azopolymer film. Since its first demonstration in 1995, the photoinduced surface-relief grating (SRG) formation has been intensively investigated in various types of azobenzene-containing mate-rials.