Suspended nanostructures grown by electron beam-induced deposition of Pt and TEOSprecursors

Abstract

Suspended nanostructures (SNSs) are grown by electron beam-induced deposition (EBID)of Pt and tetra-ethyl-ortho-silicate (TEOS) gas precursors on nanopillar tips, by lateralshifting of a scanning electron microscope beam. Shape evolution of SNSs is characterized as afunction of electron energy (5, 10, 15 keV) and electron charge deposited per unit length (CDL,1–9 pC nm−1 range) along the beam track. Pt SNSs grow as single nanowires, evolving fromthin (15–20 nm) and horizontal to thick (up to 70 nm) and inclined (up to60°) geometry as CDL increases. TEOS SNSs consist of multiple nanowires arranged in astack: horizontal and parallel along the beam shift direction and aligned on top ofeach other along the beam incidence axis. As the CDL increases, the number ofnanowires increases and the top edge of the stack progressively inclines, takingthe form of a hand-fan. Deposition yield and overall size of SNSs are found tobe proportional to CDL and inversely proportional to electron energy for bothPt and TEOS precursors. As an example of 3D nanoarchitectures achievableby this lateral EBID approach, a ‘nano-windmill’ TEOS structure is presented.