Growth and nanostructure of conformal ruthenium films by liquid-source metalorganic chemical vapor deposition

Abstract

A commercially available metalorganic compound, namely Bis (2,2,6,6-tetramethyl-3, 5-heptanedionato)(1,5-cyclooctadiene)Ruthenium, or Ru(THD)2COD was evaluated for growth, nanostructure, and conformality of ruthenium films using a manufacturable, liquid-source metalorganic chemical vapor deposition technique. The deposition of Ru films (60–200 nm) was carried out on various substrates at a temperature (Tsub) of 250–320 °C via the oxygen-assisted pyrolysis of Ru(THD)2COD. In the kinetically controlled regime, the activation energy for the deposition of Ru on amorphous-HfO2/SiO2/Si was 136 kJ/mol. However, at Tsub>290 °C, the nearly temperature-independent growth rate was indicative of the mass-transport controlled regime. The as-deposited Ru films exhibited dense and polycrystalline grain structure, with a moderate preference for the (001) orientation. X-ray photoelectron spectroscopy revealed the presence of RuO2 in metallic Ru films deposited at a Tsub as low as 260 °C. In addition, high-resolution transmission electron microscopy showed amorphous grain boundaries in Ru films and a disorder interface layer between Ru and HfO2 surface. The Ru films, however, were electrically conductive (27 μΩ cm). In addition, Ru films deposited on patterned TiN/Si substrates in the kinetically controlled regime at 250 °C exhibited nearly 100% step coverage.

CVD of Metals Using Alcohols and Metal Acetylacetonates, Part I: Optimization of Process Parameters and Electrical Characterization of Synthesized Films

“…[24][25][26] In this paper, we describe a novel, single-step process to produce non-selective, seed layer-free metal films, free from incubation time, by PSECVD using commercially available metal acetylacetonates as precursors, and alcohols alone as solvent and reducing agents. The paper is the first in a series, following the successful deposition of Ni, Cu, and Co films by this novel approach.…”

Trial for Making Three Dimensional PZT Capacitor for High Density Ferroelectric Random Access Memory

“…Pb(C 11 4 [tetrakis (1-methoxy-2-methyl-2-propoxy) zirconium, Zr(MMP) 4 ] (Asahi Denka Kogyo K. K.), and Ti(OC(CH 3 ) 2 CH 2 OCH 3 ) 4 [tetrakis(1-methoxy-2-methyl-2-propoxy)titanium, Ti(MMP) 4 ] (Asahi Denka Kogyo K. K.) were used as the respective Pb, Zr, and Ti source materials [10,11]. Ethylcyclohexane and O 2 gas were used as a solvent and as an oxidant, respectively.…”

“…Ru is also a first candidate of electrode material for realizing 3D capacitors due to the easy to get the large conformability [4][5][6][7], the ease low temperature deposition and the large switching charge.…”

Selectively deposited Ru top electrode on Pb(Zr0.3Ti0.7)O3 and Ru step coverage on TiN by digital chemical vapor deposition

“…12 The MOCVD of Ru, 8 via the pyrolysis of a Ru precursor in the direct presence of reactant oxygen gas, is not conducive for selectivity. Whereas, in digital chemical vapor deposition (DCVD), since the precursor/reactant are alternately delivered to a substrate, and chemisorption of precursor specie on OH-terminated oxide surface is favored in comparison to hydrophobic photoresist surface, selectivity may be achievable.…”

“…The details of the MOCVD process are reported elsewhere. 8 Next, polycrystalline and phase-pure Pb͑Zr 0.3 Ti 0.7 ͒O 3 (or PZT 30/ 70) thin films ͑ϳ300 nm͒ were fabricated on Ru/sapphire substrates by the sol-gel technique as also described elsewhere. 5,15,16 The selective deposition of Ru films was achieved on the exposed areas of PZT/Ru/ sapphire wafers patterned with a photoresist [see Fig.…”