Ultra-high vacuum dc magnetron sputter-deposition of 0001-textured trigonal α-Ta2C/Al2O3(0001) thin films

Borazine Promoted Growth of Highly Oriented Thin Films

“…In comparison, for Ta 2 C/(hBN)/Al 2 O 3 (0001), we see two peaks, at 2θ = 36.61° and 77.68°, respectively, due to 0002 and 0004 reflections of α-Ta 2 C, indicative of better crystallinity. The c values measured from the XRD data are comparable to those reported previously, and deviations from the bulk value are to be expected in sputter-deposited Ta 2 C thin films. , We note that the 0002 peak appears broad with satellite peaks. As we show below, the Ta 2 C layer on (hBN)/Al 2 O 3 (0001) is single-crystalline, and the satellite peaks are Laue oscillations associated with high-quality Ta 2 C layers with abrupt interfaces.…”

“…The images and the Fourier transform (FT) in the Figure C inset reveal a highly ordered lattice, indicative of single-crystallinity. From the FTs of the film and the substrate (not shown), we determine the orientation relation as false( 0001 false) normalT normala 2 normalC ∥ false( 0001 false) normalA normall 2 normalO 3 and false[ 10 1̅ 0 false] normalT normala 2 normalC ∥ false[ 11 2̅ 0 false] normalA normall 2 normalO 3 ; Ta 2 C layers deposited using the same parameters on bare Al 2 O 3 (0001) bear the same orientation relationship, consistent with previous studies . The STEM image in Figure D reveals uniform contrast across the thickness of the film, suggestive of compositional homogeneity in the film.…”

“…The c values measured from the XRD data are comparable to those reported previously, and deviations from the bulk value are to be expected in sputterdeposited Ta 2 C thin films. 32,34 We note that the 0002 peak appears broad with satellite peaks. As we show below, the Ta ; Ta 2 C layers deposited using the same parameters on bare Al 2 O 3 (0001) bear the same orientation relationship, consistent with previous studies.…”

“…All the metal (Mo, Pd, and VNbTaMoW) and compound (Ta 2 C and TaC) thin films are grown on Al 2 O 3 (0001) substrates at the desired T s via ultrahigh vacuum (UHV, base pressure <6.0 × 10 –9 Torr) direct current (dc) magnetron sputtering of the respective metal (Mo, Pd, and VNbTaMoW) and compound (TaC) targets − in a custom-designed, triple-source UHV deposition system. − All the experimental details are presented in the SI.…”

hBN-Layer-Promoted Heteroepitaxy in Reactively Sputter-Deposited MoSx≈2(0001)/Al2O3(0001) Thin Films: Implications for Nanoelectronics

“…Figure a is a plot of symmetric XRD 2θ:ω scans from the two samples, with intensities plotted on the logarithmic scale. In both scans, we find the highest intensity peaks, labeled s , at 2θ = 41.68° due to Al 2 O 3 0006 reflections of the single-crystalline α-Al 2 O 3 (0001) ( R c ) substrate and two relatively weaker intensity peaks at 2θ = 20.48° and 64.52°, corresponding to forbidden Al 2 O 3 0003 and 0009 reflections, respectively . For direct comparison of the relative intensities of the film peaks in both samples, all of the intensity values in each of the XRD scans are normalized to the intensity of the Al 2 O 3 0006 reflection.…”