Direct Writing of Cobalt Silicide Nanostructures Using Single-Source Precursors

Abstract

Two new precursors for focused electron beam-induced deposition (FEBID) of cobalt silicides have been synthesized and evaluated. The H3SiCo­(CO)4 and H2Si­(Co­(CO)4)2 single-source precursors retain the initial metal ratios and show low sensitivity to changes in the FEBID parameters such as acceleration voltage, beam current, and precursor pressure. The precursors allow the direct writing of material containing ∼55 to 60 at % total metal/metalloid content combined with high growth rates. During the deposition process an average of ∼80% of the carbonyl ligands are cleaved off in these planar deposits. Postgrowth electron curing does not change the deposits’ composition, but resistivities decrease after the curing procedure. Temperature-dependent electrical properties indicate the presence of a granular metal for both cured samples and the as-grown Co2Si deposit, while the as-grown CoSi material is on the insulating side of the metal–insulator transition. The observed magnetoresistance behavior is indicative of tunneling magnetoresistance and is substantially reduced upon postgrowth irradiation treatment.

Vanadium and Manganese Carbonyls as Precursors in Electron-Induced and Thermal Deposition Processes

“…Figure 1 c shows the volume-based material growth rate per electrical charge, which decreases with an increasing beam current. A similar trend has been described for cobalt silicide [ 34 ] and PtC x deposition [ 32 ] and is indicative of a precursor-limited regime since the growth rate is decreasing with an increasing beam current.…”

“…However, complementary four-probe measurements indicate that these parasitic contributions are negligible for the V-based FEBID material written between Au microelectrode contacts. Note that the postgrowth electron irradiation curing at a 5 kV beam voltage leads to an increase in resistance of the deposits ( Figure S3 ) and not to the typically observed reduction in resistance as described in the literature for different material systems [ 34 , 35 , 36 , 37 ]. A speculative explanation of the observed effect is oxidation due to reaction with residual water in the chamber during the electron curing process.…”

“…The observation can be assigned to diffusion effects encountered in the serpentine deposition pattern used in this study [ 31 , 32 ]. The deposition is considered to occur in the diffusion-enhanced regime as detailed in the literature and indicated by this sort of edge effect [ 33 , 34 ]. It should be noted that this edge enhancement is not observed for the structures used in the following electrical characterization due to the different loop times associated with the different geometry.…”

Focused Ion Beam vs Focused Electron Beam Deposition of Cobalt Silicide Nanostructures Using Single-Source Precursors: Implications for Nanoelectronic Gates, Interconnects, and Spintronics

“…FEBID samples for comparison were prepared as described in a prior study . Compositional analysis was performed on samples prepared at 5 kV varying the electron current from 98 pA to 6.3 nA.…”

3‐D‐Druck: Nanodruck mit Elektronenstrahlen

“…Hierbei ermöglicht die Zusammenarbeit mit der Arbeitsgruppe von Michael Huth im Physikalischen Institut Fortschritte durch Kernkompetenzen aus Chemie und Physik. 6) W…”