Crystallization of focused-electron-beam deposited tungsten wire on molybdenum substrate

Increasing attention has been paid to the usage of focused-electron-beam in the field of nanofabrication. It was verified that electron-beam-induced deposition (EBID) is capable of fabricating nanostructures on the nanometer scale. Among various precursors, tungsten hexacarbonyl [W(CO)₆] has been widely used to repair microelectronic masks and to fabricate supertips. Their properties (e.g. conductivity, field emission) are closely related to the metallic content in the structure (Hoyle, 1994). However, the as-deposited structures of W(CO)₆ are polycrystalline materials, which consist of nanocrystallines (tungsten, tungsten oxides and tungsten carbides) embedded in an amorphous carbon containing matrix (Han, 2004). In order to increase the tungsten content, heating of as-deposited tungsten wire was carried out and its crystallization on molybdenum substrate was investigated in the present study.