A comparative investigation of hetero-epitaxial TiC thin films deposited by magnetron sputtering using either hybrid DCMS/HiPIMS or reactive DCMS process

Abstract

A hybrid direct current magnetron sputtering/high-power impulse magnetron sputtering (DCMS/HiPIMS) technique was used to improve the structural and electrical properties of single-crystal titanium carbide (TiC) thin films. The hetero-epitaxial TiC films, ~ 60 nm thick, were grown on MgO (001) substrates at temperatures ranging from 200 °C to 800 °C, by co-sputtering of Ti and C targets powered by DCMS and HiPIMS, respectively. Films’ composition and the structural, morphological, and electrical properties were comparatively investigated to those of a set of samples deposited at same temperatures by reactive-DCMS (R-DCMS) in Ar/CH4 atmosphere. The composition and the FWHM of rocking curves of the films deposited by R-DCMS varied from TiC0.84 to TiC0.94 and from 1.38° to 0.64°, respectively, as the growth temperature increased. TiC0.94 - TiC0.96 layers were deposited by hybrid DCMS/HiPIMS method at temperatures higher than 400 °C, fully strained over their full thickness, with FWHM of rocking curves of about 0.13°. Electrical resistivity values measured for these films were of about 155 µΩ cm, significantly close to those corresponding to bulk TiC0.95 single crystals. The resistivity of R-DCMS films is higher by 6% to 23% in comparison with that of the DCMS/HiPIMS grown samples, depending on the growth temperature.