Direct nanopatterning of 100 nm metal oxide periodic structures by Deep-UV immersion lithography

Abstract

Deep-UV lithography using high-efficiency phase mask has been developed to print 100 nm period grating on sol-gel based thin layer. High efficiency phase mask has been designed to produce a high-contrast interferogram (periodic fringes) under water immersion conditions for 244 nm laser. The demonstration has been applied to a new developed immersion-compatible sol-gel layer. A sol-gel photoresist prepared from zirconium alkoxides caped with methacrylic acids was developed to achieve 50 nm resolution in a single step exposure. The nanostructures can be thermally annealed into ZrO(2). Such route considerably simplifies the process for elaborating nanopatterned surfaces of transition metal oxides, and opens new routes for integrating materials of interest for applications in the field of photocatalysis, photovoltaic, optics, photonics or microelectronics.

Direct Laser Writing of Crystallized TiO2 and TiO2/Carbon Microstructures with Tunable Conductive Properties

“…Electronic properties are indeed closely linked to the nature of the metal and conditions of fabrication, which determine the structure of the final material at the atomic scale. These properties can be modified by doping with different metals, by adjusting the metal to oxygen stoichiometry or by generating an amorphous or crystal phase …”

“…At the molecular scale, the patterning proceeds according to the photodecomposition of the metal precursors complexed by organic molecules. Patterning can be obtained at room temperature down to the nanoscale using direct laser writing (DLW), but usually, a thermal post‐treatment is needed to obtain an MO with suitable optical or electrical properties . For example, Yeh et al have shown that laser irradiation of a zinc oxide (ZnO) sol–gel‐based photoresist using DUV lithography can produce nanostructures .…”

Deep ultraviolet laser direct write for patterning sol-gel InGaZnO semiconducting micro/nanowires and improving field-effect mobility

“…Zinc methacrylate precursor was chosen because metal methacrylate complexes have been proved to exhibit high sensitivity in the DUV range allowing light-induced crosslinking. Thus they were used as photosensitive building blocks to generate nanopatterning by laser direct write 17 18 . The emission wavelength of the DUV laser is 193 nm.…”

Nanoscale Ferromagnetic Cobalt‐Doped ZnO Structures Formed by Deep‐UV Direct‐Patterning

“…The feature line‐width of photopatterned metal oxide structures is related to both photosensitivity of metal oxide precursor and the wavelength of light source. Submicro‐ or nanoscale dimensions can be achieved with the use of high photosensitive metal oxide precursors and short wavelengths light sources such as deep‐UV (DUV) (193 nm) and extreme UV (13.5 nm), making photopatterning a promising technology for fabricating micro or even nanoscale devices . Moreover, photopatterning can be applied to obtain multielement metal oxide materials by mixing photosensitive precursor in conditions that control their dispersion at the atomic scale …”