Abstract

We describe the fabrication of three-dimensional (3D) photonic microstructures by high resolution X-ray lithography (XRL) as the first step toward 3D photonic band gap (PBG) materials for mid-and near-infrared wavelengths. In the soft X-ray range (λ~1 nm), the conventional XRL mask technology can be used to fabricate 3D «Yablonovite» structures in relatively thick PMMA resist layers (from 4 to 10 µm). Three consecutive expositions under a tilt angle of 35.26° with respect to the normal to the substrate and a rotation angle of 120° between each exposure are performed in the vacuum chamber of a broad band synchrotron radiation facility (SuperACO, Orsay, France). A triangular lattice of holes is used as a pattern for the membrane-supported XRL mask. Several specific mask configurations were tested to solve the problems of stability and alignment related to the multiple tilt exposures.

© 2000 IEEE