Direct Laser Writing of Microscale 3D Structures: Morphological and Mechanical Properties

Microscale 3D structure realization nowadays is possible due to the direct laser writing (DLW)-photolithography. The DLW-photolithography technology provides a unique way to fabricate X-ray lenses with arbitrary shape and curvature radius less than 10 mu m. However, an achievement of mechanically stable lithographic features is in demand for the fabrication of microoptical elements with high curvature values including X-ray lenses. According to this purpose, the research based on novel and promising methacrylate-containing material photocomposition for the DLW-photolithography is carried out. Improved solubility (1%wt) provides a large fabrication window, so it increases opportunities for use in the DLW-photolithography. A comprehensive study of the mechanical and morphological properties of the photocomposition makes it possible to determine the optimum DLW-photolithography parameters to fabricate mechanically-stable compound-refractive-lens (CRL) element. We use experimental methods of nanoindentation, confocal microscopy, and atomic force microscopy (AFM). The saturation value of reduced Young's modulus equal to 2.00 +/- 0.20 GPa is reached at a laser power of 5 mW and at a speed of 180 mu m/s.