High Vertical Resolution 3D NanoImprint Technology and its Application in Optical Nanosensors
Alla Albrecht, Xiaolin Wang, Hanh Hong Mai, Timo Schotzko, Imran Memon, Martin Bartels, Michael Hornung and Hartmut Hillmer
Photonic components, including functionalized nanostructured surfaces, obtain increasing importance. With decreasing size, the physical limits of conventional fabrication techniques such as photolithography and etching are encountered. Conventional NanoImprint templates are mainly focused on only high lateral resolution down to 5 nm [1]. Thus, three dimensional (3D) photonic nanostructures, requiring also precise vertical height-control, cannot be addressed on the basis of the conventional technology. In this paper, we present high vertical resolution 3D NanoImprint technologies and its applications concerning strongly miniaturized spectrometers (nanospectrometers) with optical resolution (λ/Δλ) up to 500. Our nanospectrometer consists of a 2D array of Fabry-Pérot (FP) filters, designed to match exactly to a 2D CCD detector array in lateral direction with a resulting system size of 2 × 2 × 4 mm3. The 3D filter cavities were imprinted using both 3D UV-NanoImprint (UV-NI) technology and Substrate Conformal Imprint Lithography (SCIL). For the deposition of Distributed Bragg Reflectors (DBRs), Plasma Enhanced Chemical Vapour Deposition (PECVD) as well as Ion Beam Sputtering Deposition (IBSD) were applied. The filter arrays required for the spectrometer have been demonstrated to have an ultra-high transmittance > 80 % and a Full Width at Half Maximum (FWHM) of down to 1 nm.
Keywords: 3D NanoImprint, nanospectrometer, Fabry-Pérot filter array, high spatial and spectral resolution.