Chemical vapor deposition of WNxCy using the tungsten piperidylhydrazido complex Cl4(CH3CN)W(N-pip): Deposition, characterization, and diffusion barrier evaluation

Abstract

The tungsten piperidylhydrazido complex Cl 4 ͑CH 3 CN͒W͑N-pip͒ ͑1͒ was used for film growth of tungsten carbonitride ͑WN x C y ͒ by metal-organic chemical vapor deposition ͑CVD͒ in the absence and presence of ammonia ͑NH 3 ͒ in H 2 carrier. The microstructure of films deposited with NH 3 was x-ray amorphous between 300 and 450°C. The chemical composition of films deposited with NH 3 exhibited increased N levels and decreased C levels over the entire deposition temperature range ͑300-700°C͒ as compared to films deposited without NH 3. As determined by x-ray photoelectron spectroscopy, W is primarily bonded to N and C for films deposited at 400°C, but at lower deposition temperature the binding energy of the W-O bond becomes more evident. The growth rates of films deposited with NH 3 varied from 0.6 Å / min at 300°C to 4.2 Å / min at 600°C. Over 600°C, the growth rate decreased when using NH 3 presumably due to parasitic gas phase reactions that deplete the precursor. Diffusion barrier properties were investigated using Cu/ WN x C y / Si stacks consisting of 100 nm Cu deposited at room temperature by reactive sputtering on a 20 nm WN x C y film deposited at 400°C by CVD. X-ray diffraction and cross-sectional transmission electron microscopy were used to determine the performance of the diffusion barrier. Cu/ WN x C y / Si stacks annealed under N 2 at 500°C for 30 min maintained the integrity of both Cu/ WN x C y and WN x C y / Si interfaces.

Fabrication and mechanical properties of tungsten carbide thin films via mist chemical vapor deposition

“…The film obtained at 850 °C has a particularly high C/W ratio. We speculate that the film contains amorphous carbon (a-C), similar to a previously reported WNxCy film formed at a high temperature by aerosol-assisted CVD [32]. The columnar structure seen in the SEM image of the film obtained at 850 °C (Fig.…”

Synthesis and Evaluation of Molybdenum Imido-Thiolato Complexes for the Aerosol-Assisted Chemical Vapor Deposition of Nitrogen-Doped Molybdenum Disulfide

“…For N-doped MoS 2 , S-bound ligands from prior single-source precursors for MoS 2 could be used in combination with a nitrogen source, most likely from N-bound ligands. Nitrogen-coordinated ligands such as imido, − nitrido, amido, , amidinato, and hydrazido , moieties have been used as sources of nitrogen in depositions of metal nitride and carbonitride films. These ligands could also serve as nitrogen sources for N-MoS 2 .…”

Low Temperature Deposition of WNxCyDiffusion Barriers Using WN(NEt2)3as a Single-Source Precursor

“…33 Similar WN x C y films (grown in the same reactor under similar conditions) exhibited resistivities between 225 μ -cm and 87 m -cm, although typically less than 5000 μ -cm. 15,19,34 It was shown that both an increase of C and decrease of N incorporation in the W sub-lattice can lower film resistivity; however there also exists interplay between grain size, grain boundary density, crystallinity, film density, elemental composition and valence states, as well as film thickness. Below 200 • C, O incorporation is prominent and is most likely due to background oxygen and water vapor in the deposition chamber, as well as the low film density, which could accommodate significant post-growth oxygen incorporation.…”

“…Typically, these complexes include nitrogen-bound moieties such as amido, imido, hydrazido, amidinate or guanidinate ligands, 13,14 and have been used in single-source or NH 3 /H 2 co-reacting conditions to deposit WN x . Unfortunately, many of these precursors still require relatively high deposition temperature (>350 • C) [15][16][17][18][19][20][21][22] that can compromise contact level structures 2,23 and neighboring dielectrics. 24 In addition, the development of ultra-low temperature CVD WN x C y has potential application to flexible and organic devices.…”