Deliverable D2 (D1.4) - Functional quantum device grown with FEBID

Superconductors are one of the building blocks for most nanodevices used in quantum applications. The direct local writing aspect of the Focused Electron Beam Induced Deposition (FEBID) technique allows for flexible deposition of any materials and especially metals and superconductors. As clean bulk material tungsten (W) has a superconducting transition temperature Tc = 15 mK only and a critical field Bc = 0.12 mT. Tc can be increased by introducing disorder and carbon incorporation to about 5.5 K and Bc to 9.5 T using e.g. ion- induced deposition techniques [3, 4]. Superconducting tungsten fabricated by FEBID has been so far reported only twice in the literature [1, 2]. Here we report the use of tungstenhexacarbonyl W(CO)6 molecules as a precursor for fabricating superconducting tungsten by FEBID.