LIGA is a well-established process to fabricate metallic micro parts with high resolution, high precision and very low sidewall
roughness by means of X-ray lithography and electroplating. Typical mask substrate materials, e.g. beryllium, carbon based foils,
Si<sub>3</sub>N<sub>4</sub> or SiC show different disadvantages such as low X-ray transparency or high toxicity or high prices or low conductivity or high
thermal expansion or surface porosity causing X-ray scattering. Due to the amorphous structure of vitreous carbon this mask material
proved to significantly reduce the amount of side wall striations, leading to extremely smooth pattern sidewalls. For the fabrication of
X-ray masks, PMMA with its unique features such as high aspect ratio patterns with high precision, exhibits low sensitivity and the
layers preparation is not easy. SU-8, an epoxy-based UV and X-ray sensitive, chemically amplified negative tone photoresist exhibits
high aspect ratio patterns with vertical sidewalls. The difficult remove of the resist after the electroplating process significantly
hinders the inspection of the fabricated X-ray mask. We present the suitability of an UV sensitive, chemically amplified, aqueous-alkaline
developable, and easy removable positive tone photoresist, XP mr-P 15 AV for the fabrication of X-ray masks by means of
UV lithography on vitreous carbon substrates.
The paper presents our experimental results achieved on the field of investigation of LPCVD silicon nitride based two
dimensional photonic crystals for visible wavelengths. Our research concentrates on the photonic band gap and defect
engineering with respect to the use of silicon nitride based photonic crystals as optical resonators in the visible range of
electromagnetic spectra. In order to optically characterize the fabricated photonic crystals, transmission setup utilizing
broad band white light source is being used. Using this setup, photonic band gaps in the range between 500 and 900 nm,
and thus covering the entire transmission range of LPCVD silicon nitride in the visible range, could be identified for
various values of the slab thickness. By incorporating line defects, we fabricated and investigated several photonic
crystal filter demonstrators. By optimizing the defect geometry, we achieved transmission values of over 85%.
SiN is a promising candidate for the fabrication of photonic crystals (PCs)
with band gaps in the wavelength range between 550 nm and 850 nm. Here, we investigate the optical properties of
cavities in SiN PC membranes by fluorescence spectroscopy of embedded emitters. For this purpose a dye solution is spin-cast on top of the PC membranes and the fluorescence is studied using a confocal microscopy setup. We observe strong emission resonances of molecules spatially and spectrally coupled to the cavity modes. These resonances are compared to finite-difference time-domain simulations of the PC structures, allowing an optimization of the cavity geometry to achieve high quality factors (several hundreds to nearly one thousand). Furthermore, we study routes to selectively incorporate single emitting particles into the cavities applying scanning probes. In this way we introduce SiN PC cavities as universal tools for the manipulation of the emission properties of a huge variety of different emitters in the visible.
Photonic crystal device based on silicon nitride resonant cavity and acting as a band pass filter is presented. The devise consists of an incoming waveguide, coupling dipole cavity and outgoing waveguide. High transmission for resonant frequency and sufficient attenuation for other frequencies is achieved. Results of band gap and transmission calculations as well as the fabrication approach and fabricate structures are presented. Measurement setup to experimentally prove the predicted optical properties is presented.