Conductive TiN thin films grown by plasma-enhanced atomic layer deposition: Effects of N-sources and thermal treatments

Abstract

This work consists of optimizing TiN plasma-enhanced atomic layer deposition using two different N-sources: NH[Formula: see text] and N[Formula: see text]. In addition to maximizing the growth per cycle (GPC) and to shorten the deposition duration, comprehensive in situ and ex situ physicochemical characterizations give valuable information about the influence of the N-source nature, their dilution in Ar, and the plasma power on layer’s final properties. N[Formula: see text] and NH[Formula: see text] dilutions within Ar are extensively investigated since they are critical to decreasing the mean free path ([Formula: see text]) of plasma-activated species. A 1:1 gas ratio for the N-sources:Ar mixture associated with low flows (20 sccm) is optimal values for achieving highest GPCs (0.8 Å/cycle). Due to lower reactivity and shorter [Formula: see text] of the excited species, N[Formula: see text] plasma is more sensitive to power and generator-to-sample distance, and this contributes to lower conformality than with NH[Formula: see text] plasma. The resistivity of the initial amorphous films was high ([Formula: see text] cm) and was significantly reduced after thermal treatment ([Formula: see text] cm). This demonstrates clearly the beneficial effect of the crystallinity of the film conductivity. Though N[Formula: see text] process appears slightly slower than the NH[Formula: see text] one, it leads to an acceptable film quality. It should be considered since it is nonharmful, and the process could be further improved by using a reactor exhibiting optimized geometry.

Enhanced sensitivity towards hydrogen by a TiN interlayer in Pd-decorated SnO2 nanowires

“…3b). According to earlier studies, 62,63 several contributions such as a nitride, oxynitride and oxide can be detected on the Ti 2p area, when TiN lms are grown by this ALD process. Oxide and oxynitride contributions were ascribed to the oxidation of the top surface of the layer.…”

“…TiN lms were grown by thermal ALD in a shower-head geometry reactor Fiji 200 (Veeco/Cambridge Nanotech) according to the previous studies. 62,63 TDMAT (99.99%, Strem Chemicals) and NH 3 ($99.999%, from Linde Electronics) were used as the Ti precursor and N-source, respectively, and Ar ($99.999%, from Linde Electronics) served as the vector gas. TDMAT was maintained at 70 °C and the chamber temperature was xed at T TiN = 200 °C.…”

“…TiN lms exhibiting low carbon contamination, low roughness and low resistivity have already been conformally deposited using TDMAT and NH 3 onto different structured substrates such as nanoporous alumina and macroporous silicon. 62,63 The ALD of Pd has been successfully performed on various substrates such as Ni, BN, and TiO 2 . 42,43,64,65 Compared to TiN deposition, where both precursors, TDMAT and NH 3 , are involved in the growth of the lm, the Pd process deals with the reduction to metallic Pd and the elimination of the ligands of the Pd precursor by the co-reactant.…”

“…TiN films exhibiting low carbon contamination, low roughness and low resistivity have already been conformally deposited using TDMAT and NH 3 onto different structured substrates such as nanoporous alumina and macroporous silicon. 62,63…”