Application of X-ray lithography for fabrication microstructures with 3D-continuous-relief.
- Dr. Boris GOLDENBERG
- Dr. Boris GOLDENBERG (Budker Institute of Nuclear Physics)
- Mr. Vladimir NAZMOV (Budker Institute of Nuclear Physics)
- Mr. Aleksey LEMZYAKOV (Budker Institute of Nuclear Physics)
- Mr. Alexander VARAND (Institute of Solid State Chemistry and Mechanochemistry)
- Mrs. Tatyana KAZANTSEVA (Budker Institute of Nuclear Physics)
- Mr. Aleksandr GENTSELEV (Budker Institute of Nuclear Physics)
In the classical scheme of X-ray lithography, the planar pattern is transferred from the X-ray mask to the resist layer. The depth of the resulted structures is determined by the irradiation spectrum and absorbed dose and mode of development. The vertical smooth walls along the entire depth of the structure is advantage of X-ray lithography. On the other hand, in some tasks of manufacturing micromechanical systems or micro-optical systems (MEMS or MOMS), the formation of microstructures with a smooth continuous profile of a given shape is required. X-ray lithography can be used to solve this problem. This can be achieved using gray-scale X-ray mask, where the thickness of the X-ray opaque coating changes along the surface of the template. In this case, during the exposition time, different sections of the resist will receive different exposure doses. And with simultaneous development, the depth of sructures will correspond to the distribution of the dose across the surface of the resistHowever, making gray-scale X-ray masks is a hard technological challenge. An alternative to making gray-scale X-ray patterns is the use of a specific method of dynamic X-ray lithography. This is the process in which the resist moves relative to the X-ray pattern during exposition. The resulting exposure dose is determined by the shape of the transparent areas on the mask, taking into account the characteristic curve for the resist used. The choice of X-ray pattern topology for obtaining a given curvature of microstructures in PMMA resist is considered in the article. Samples of the microstructures obtained are shown. The work was done using the infrastructure of the Shared-Use Center “Siberian Synchrotron and Terahertz Radiation Center (SSTRC)” based on VEPP-3 of BINP SB RAS (Novosibirsk, Russian Federation).