Compositional dependence of epitaxial Tin+1SiCn MAX-phase thin films grown from a Ti3SiC2 compound target (original) (raw)
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Journal of vacuum science & technology, 2019
We investigate sputtering of a Ti3SiC2 compound target at temperatures ranging from RT (no applied external heating) to 970 o C as well as the influence of the sputtering power at 850 o C for the deposition of Ti3SiC2 films on Al2O3(0001) substrates. Elemental composition obtained from time-of-flight energy elastic recoil detection analysis shows an excess of carbon in all films, which is explained by differences in angular distribution between C, Si and Ti, where C scatters the least during sputtering. The oxygen content is 2.6 at.% in the film deposited at RT and decreases with increasing deposition temperature, showing that higher temperatures favor high purity films. Chemical bonding analysis by X-ray photoelectron spectroscopy shows C-Ti and Si-C bonding in the Ti3SiC2 films and Si-Si bonding in the Ti3SiC2 compound target. X-ray diffraction reveals that the phases Ti3SiC2, Ti4SiC3, and Ti7Si2C5 can be deposited from a Ti3SiC2 compound target at substrate temperatures above 850 o C and with growth of TiC and the Nowotny phase Ti5Si3Cx at lower temperatures. Highresolution scanning transmission electron microscopy shows epitaxial growth of Ti3SiC2, Ti4SiC3, and Ti7Si2C5 on TiC at 970 o C. Four-point probe resistivity measurements give values in the range ~120 to ~450 µWcm and with the lowest values obtained for films containing Ti3SiC2, Ti4SiC3, and Ti7Si2C5.
Ti3SiC2-formation during Ti–C–Si multilayer deposition by magnetron sputtering at 650 °C
Vacuum, 2013
Ti 3 SiC 2 films were deposited from three separate magnetrons with elemental targets onto Si wafer substrates. The substrate was moved in a circular motion such that the substrate faces each magnetron in turn and only one atomic species (Ti, Si or C) is deposited at a time. This allows layer-by-layer film deposition. Material composition was determined by energy dispersive X-Ray (EDX). High resolution transmission electron microscopy (HRTEM) and Raman spectroscopy were used to gain insights into thin film atomic structure arrangements. Using this new deposition technique, at a deposition temperature of 650 0 C formation of Ti 3 SiC 2 MAX phase was obtained, while at lower temperatures phase separation is observed and only silicides and carbides are formed. Significant sharpening of Raman E 2g and A g peaks associated with Ti 3 SiC 2 formation was observed.
Journal of Vacuum Science & Technology B, Nanotechnology and Microelectronics: Materials, Processing, Measurement, and Phenomena, 2017
This article reports on the direct current sputtering of AlN thin films on top of a cubic-silicon carbide (111) on silicon (111) substrates. The authors varied the nitrogen (N 2) concentrations, while keeping other process parameters fixed at the power of 1200 W, the substrate temperature of 350 C, the target to substrate distance of 20 cm, and the sputtering pressure of 2 mT. The total N 2 /Ar gas flow is 50 sccm, and the poison mode starts at 40%. The x-ray diffraction results show that the AlN films are highly oriented along the (002) orientation at various N 2 concentrations. The values of the three parameters support this observation, namely, (1) the extracted full width at half maximum (FWHM) of (002) diffraction peaks with the median of 0.28 and the standard deviation of 0.012 , (2) the area of AlN (002) under the curve is between 92% and 97%, and (3) the grain sizes are between 30.11 and 32.3 nm. The omega scan rocking curve of two samples at 40% and 80% N 2 concentrations depicts good quality AlN (002) films with the FWHM values of 1.5 and 2 , respectively. The relationship between the N 2 concentrations and the film's properties is elucidated. Finally, the authors discuss the effect of the lattice mismatch of 1% between AlN (002) and 3C-SiC (111). V
Advances in Science and Technology, 2006
Epitaxial M n+1 AX n phase (n=1, 2 or 3) thin films from the chemically related Ti-Si-C, Ti-Ge-C, and Ti-Sn-C systems were grown on Al 2 O 3 (0001) substrates at temperatures in the region of 700-1000 o C, using d.c. magnetron sputtering from individual sources. In addition to growth of the known phases Ti 3 SiC 2 , Ti 3 GeC 2 , Ti 2 GeC, and Ti 2 SnC the method allows synthesis of the new phases Ti 4 SiC 3 , Ti 4 GeC 3 , and Ti 3 SnC 2 as well as the intergrown structures Ti 5 A 2 C 3 and Ti 7 A 2 C 5 in the Si and Ge systems. Characterization by XRD, TEM and nanoindentation show similarities with respect to phase distribution, mechanical, and electrical properties, particularly pronounced when comparing Si and Ge. The Ti-Sn-C system is, however, the most liable system with respect to surface segregation of the A-element. This causes less favorable growth of MAX phases as seen by a preferential growth of the binary carbide TiC and metallic Sn. Nanoindentation on films from the Ti-Si-C and Ti-Ge-C systems shows large plastic deformation with extensive pile up. The typical thin film hardness is ∼20 GPa, and the Young's modulus in the region of 320 GPa. The four-point probe resistivity is low for all systems, but differs depending on materials system and phase, with values of ∼25 µΩcm for Ti 3 SiC 2 , and ∼17 µΩcm for Ti 2 GeC.
Micromachines, 2019
Many strategies have been developed for the synthesis of silicon carbide (SiC) thin films on silicon (Si) substrates by plasma-based deposition techniques, especially plasma enhanced chemical vapor deposition (PECVD) and magnetron sputtering, due to the importance of these materials for microelectronics and related fields. A drawback is the large lattice mismatch between SiC and Si. The insertion of an aluminum nitride (AlN) intermediate layer between them has been shown useful to overcome this problem. Herein, the high-power impulse magnetron sputtering (HiPIMS) technique was used to grow SiC thin films on AlN/Si substrates. Furthermore, SiC films were also grown on Si substrates. A comparison of the structural and chemical properties of SiC thin films grown on the two types of substrate allowed us to evaluate the influence of the AlN layer on such properties. The chemical composition and stoichiometry of the samples were investigated by Rutherford backscattering spectrometry (RBS) and Raman spectroscopy, while the crystallinity was characterized by grazing incidence X-ray diffraction (GIXRD). Our set of results evidenced the versatility of the HiPIMS technique to produce polycrystalline SiC thin films at near-room temperature by only varying the discharge power. In addition, this study opens up a feasible route for the deposition of crystalline SiC films with good structural quality using an AlN intermediate layer.
Journal of Applied Physics, 1993
Reactive magnetron sputtering in a mixed Ar/CH, discharge has been used to deposit 3C-Sic films on ( 111 )-oriented Si substrates. The carbon content as well as the crystalline structure was found to depend on both the CH4 and Ar pressures. At a total pressure of 3 mTorr and a CH4 partial pressure of 0.6 mTorr, epitaxial stoichiometric films were obtained at growth temperatures as low as 850 "C. The epitaxial nature of the films was established by x-ray diffraction using a combination of reciprocal space maps, texture scans, and 360" q$ scans. Based on these analyses it could also be concluded that double-positioning domains rotated 60" to one another as well as other defects, giving rise to a mosaic broadening in the reciprocal space maps, were present in the films. Furthermore, based on plasma probe measurements and determination of the electron energy distribution functions in the near-substrate vicinity, the low growth temperature of 850 "C! is suggested to be a consequence of an effective decomposition of CH4 molecules in the plasma.
Many strategies have been developed for the synthesis of silicon carbide (SiC) thin films on silicon (Si) substrates by plasma-based deposition techniques, especially plasma enhanced chemical vapor deposition (PECVD) and magnetron sputtering, due to importance of these materials for microelectronics and related fields. A drawback is the large lattice mismatch between SiC and Si. The insertion of a thin aluminum nitride (AlN) buffer layer between them has been shown useful to overcome this problem. Herein, the high-power impulse magnetron sputtering (HiPIMS) technique was used to grow SiC thin films on AlN/Si substrates. Furthermore, the SiC films were also grown on Si substrates. Comparisons of the structural and chemical properties of SiC thin films grown on the two types of substrates allowed us to evaluate the influence of AlN buffer layer on such properties. The chemical composition and stoichiometry of the samples were investigated by Rutherford backscattering spectrometry (RBS...
Room temperature epitaxial growth of TiN on SiC
Surface and Coatings Technology, 2007
Epitaxial growth of a titanium nitride (TiN) on (6H)-SiC (0001) is achieved at room temperature by means of direct current magnetron sputtering. The epitaxial relationship is established by X-ray pole figure and Φ-scan. Cross-sectional transmission electron microscopy and pole figure analysis show that the orientation relationship is ð111Þ TiN jjð0001Þ SiC ½011 TiN jj½1210 SiC ; It is different from that on sapphire, "ð111Þ TiN jjð0001Þ Al2O3 ½101 TiN jj½1010 Al2O3 "; in spite of the same crystal structure of substrate surfaces. Different lattice mismatch is a plausible explanation.
Thin Solid Films, 1995
ABSTRACT Cubic silicon carbide (3C-SiC) films were grown on Si substrates at 850 °C by sputtering of a pure-Si target in mixed Ar + CH4 discharges. Films were grown on Si(111), (001) and 4 ° off-oriented (001) substrates. The effects of CH4 partial pressure (PCH4) on the film composition and microstructure were investigated using Auger electron spectroscopy, Rutherford backscattering analysis, X-ray diffraction and transmission electron microscopy. Epitaxial stoichiometric 3C-SiC films were obtained at PCH4 = 0.6 mTorr. Lower methane partial pressure resulted in C-deficient films with a phase mixture of polycrystalline Si and amorphous SiC at PCH4 = 0.4 mTorr. Increasing PCH4 to 0.8 mTorr resulted in the growth of columnar SiC films with graphite precipitates at the grain boundaries. 3C-SiC epitaxial films deposited on Si(111) substrate showed a columnar structure from double-positioning domains. Films grown on Si(001) substrates resulted in smooth films, but with antiphase domain boundaries. The domain structure was removed when the films were grown on 4 ° off-oriented Si(001).