Department of Electrical and Computer Engineering, University of Pittsburgh, Pittsburgh, PA 15261, USA.
Nanotechnology. 2011 Jan 21;22(3):035303. doi: 10.1088/0957-4484/22/3/035303. Epub 2010 Dec 9.
We report a combined holographic and nanoimprinting lithography technique to produce three-dimensional woodpile photonic crystal templates through only one single exposure. The interference lithography process uses an integratable diffractive optical element for large throughout 3D pattern manufacturing. The diffractive optical element consists of two layers of phase grating separated by an intermediate layer, fabricated by repeated nanoimprinting lithography, followed by an SU8 photoresist bonding technique. Grating periods, relative orientation, diffraction angle, and efficiency, as well as layer to layer phase delay, are well designed during manufacturing. By thermally optimizing the thickness of the intermediate layer, this paper demonstrates the fabrication of interconnected 3D photonic structures with arbitrary symmetry through a single laser exposure. The two-layer phase mask approach enables a CMOS-compatible monolithic integration of 3D photonic structures with other integrated optical elements and waveguides.
我们报告了一种结合全息和纳米压印光刻技术，通过单次曝光即可制作三维木堆光子晶体模板。干涉光刻过程使用可集成的衍射光学元件实现大吞吐量的 3D 图案制造。衍射光学元件由通过重复纳米压印光刻和 SU8 光致抗蚀剂键合技术制造的两层相位光栅组成。在制造过程中，对光栅周期、相对取向、衍射角和效率以及层间相位延迟进行了精心设计。通过对中间层厚度进行热优化，本文通过单次激光曝光演示了任意对称的互连 3D 光子结构的制造。双层相位掩模方法可实现与其他集成光学元件和波导的 3D 光子结构的 CMOS 兼容单片集成。
