Trimethylaluminum as a Reducing Agent in the Atomic Layer Deposition of Ti(Al)N Thin Films

Abstract

Ti(Al)N thin films were deposited by atomic layer deposition (ALD) from titanium tetrachloride, ammonia, and trimethylaluminum. The most important role of trimethylaluminum was to act as an extra reducing agent in order to lower the required deposition temperature. The films were deposited using four different schemes, where the pulsing order and pulse time of the reactants, and the deposition temperature, were varied. The film properties were analyzed by energy dispersive X-ray spectroscopy (EDX), time-of-flight elastic recoil detection analysis (TOF-ERDA), X-ray diffraction (XRD), and resistivity measurements. Additionally, the diffusion barrier properties of selected 10 nm thick films were studied. Both carbon and aluminum were incorporated into the Ti(Al)N films. Despite that, at deposition temperatures of 400 C and lower, Ti(Al)N films exhibited better characteristics than TiN films deposited from titanium tetrachloride and ammonia.

Investigation of N Type Metal TiAlC by Thermal Atomic Layer Deposition Using TiCl4and TEA as Precursors

“…Similar results have been reported by other researchers when TiCl 4 is employed in ALD. 14,15 The composition of C is approximately unchanged in the range of 36%∼42%. The composition of Al dramatically increases from 13% to 35% while the composition of Ti decreases markedly from 45% to 25% when the temperature increases from 250 • C to 375 • C. This is because more TEA decomposes to Al at higher temperatures, which contribute to higher Al content and comparatively lower Ti content.…”

Atomic/Molecular Layer Deposited Iron–Azobenzene Framework Thin Films for Stimuli‐Induced Gas Molecule Capture/Release

“…The trans isomer of the azobenzene moiety exhibits as trong p-p* absorption peak around 333 nm, while for the cis isomer aw eak (forbidden) n-p*b and is expected at 550. [39,40] Before investigating the guest absorption capability of the iron-azobenzene thin films,w ee laborated our ALD/MLD process by optimizing the deposition parameters in more detail (see the Supporting Information). [34] Also,i ti si nteresting to note as shown in Figure 1d that the absorbance at 333 nm increases linearly with the number of ALD/MLD cycles applied, in an excellent agreement with the ideally expected regular film growth.…”

Atomic/Molecular Layer Deposited Iron–Azobenzene Framework Thin Films for Stimuli‐Induced Gas Molecule Capture/Release

“…The XPS data also reveal the presence of Cl contamination (ca. 1 at %), which is typical for ALD and MLD films grown from metal chloride precursors in particular at low deposition temperatures …”