Temperature-Dependent Growth Characteristics of Nb- and CoFe-Based Nanostructures by Direct-Write Using Focused Electron Beam-Induced Deposition

Abstract

Focused electron and ion beam-induced deposition (FEBID/FIBID) are direct-write techniques with particular advantages in three-dimensional (3D) fabrication of ferromagnetic or superconducting nanostructures. Recently, two novel precursors, HCo 3 Fe(CO) 12 and Nb(NMe 3 ) 2 (N-t-Bu), were introduced, resulting in fully metallic CoFe ferromagnetic alloys by FEBID and superconducting NbC by FIBID, respectively. In order to properly define the writing strategy for the fabrication of 3D structures using these precursors, their temperature-dependent average residence time on the substrate and growing deposit needs to be known. This is a prerequisite for employing the simulation-guided 3D computer aided design (CAD) approach to FEBID/FIBID, which was introduced recently. We fabricated a series of rectangular-shaped deposits by FEBID at different substrate temperatures between 5 ° C and 24 ° C using the precursors and extracted the activation energy for precursor desorption and the pre-exponential factor from the measured heights of the deposits using the continuum growth model of FEBID based on the reaction-diffusion equation for the adsorbed precursor.

Irradiation driven molecular dynamics simulation of the FEBID process for Pt(PF$_3$)$_4$

“…Morphology of the nanostructures grown during the FEBID process has not yet been thoroughly investigated on the atomistic level although it governs many physical properties such as electrical and thermal conductivity, and magnetic properties [26,27]. Atomistic simulations provide insights into the internal structure of the deposits and its evolution depending on the regimes of the FEBID process.…”

FEBID 3D-Nanoprinting at Low Substrate Temperatures: Pushing the Speed While Keeping the Quality

“…Recently, Huth et al analyzed the growth rates of two-dimensional pads at substrate temperatures between 5 and 24 • C for different precursors [31]. For the Pt-precursor (Me 3 CpMePt), which is also used in the present study, the deposit grew up to 6-fold higher [31]. These FEBID experiments in 2D indicate that a cooled substrate may also be suitable to increase the growth rates for 3-dimensional deposits.…”

“…However, the minimal feature size and geometrical flexibility suffer and complex 3-dimensional structures cannot be realized [1]. Recently, Huth et al analyzed the growth rates of two-dimensional pads at substrate temperatures between 5 and 24 • C for different precursors [31]. For the Pt-precursor (Me 3 CpMePt), which is also used in the present study, the deposit grew up to 6-fold higher [31].…”

Irradiation-driven molecular dynamics simulation of the FEBID process for Pt(PF3)4

“…The morphology of the nanostructures grown during the FEBID process has not yet been thoroughly investigated on the atomistic level although it governs many physical properties such as electrical and thermal conductivity, and magnetic properties [ 27 – 28 ]. Atomistic simulations provide insights into the internal structure of the deposits and its evolution depending on the regimes of the FEBID process.…”