Nanolithography made from water-based spin-coatable LSMO resist

A dual functional and water soluble spin-coatable lanthanum strontium manganese oxide (LSMO) resist has been developed that consists of lanthanum nitrate, strontium nitrate, manganese nitrate, polyvinyl alcohol and water. Energetic nitrates plus polyvinyl alcohol fuel promote autoignition and produce nanopatterns (<60 nm) upon mild electron beam exposure (<2 mC cm−2). The formation of cubic perovskite LSMO has been confirmed by micro-IR spectroscopy, elemental analysis, x-ray diffraction and transmission electron microscopy. The patterned LSMO film can be developed using nontoxic and environmentally friendly pure water, and the resist can fabricate active magnetic patterns directly by electron beam exposure. The spin-coatable LSMO resist can be fabricated into either positive or negative patterns easily by varying the electron doses. It can change from negative resist to positive resist and then finally negative resist with the increase of electron dose. The positive and negative dual functional mechanism of spin-coatable LSMO resist is reported. A resist with simultaneous positive and negative capabilities patterning will benefit the direct writing technology of an electron beam. The active magnetic characteristics and high refractive index of the material are useful for the direct fabrication of magnetic and optical devices. (Some figures in this article are in colour only in the electronic version)