12039-83-7Relevant academic research and scientific papers
Surface nucleation of Ti silicides at elevated temperatures
Tung
, p. 1933 - 1935 (1996)
The nucleation of Ti silicide at the surfaces of Si was studied. Deposition of Ti and codeposition of TiSix at elevated temperatures on single crystal and amorphous Si led to the direct growth of silicides. The temperature and composition of the deposition and the crystallinity of the substrate were found to have a strong effect on the phases(s) of the silicide layer. A remarkably low nucleation temperature, ～500°C, for the low-resistivity C54-TiSi2 phase was observed on amorphous Si. Stoichiometric and uniform TiSi2 layers were grown with the depositions of pure Ti. On crystalline Si, uniform TiSi2 layers were also grown at ～500°C with the deposition of essentially Ti. The significant difference between silicide formation in the present scheme and that under conventional silicide processing was discussed in terms of a possible circumvention of precursor amorphous salicide phases during surface nucleation.
Mechanism of low temperature C54 TiSi2 formation bypassing C49 TiSi2: Effect of Si microstructure and Mo impurities on the Ti-Si reaction path
Kittl,Gribelyuk,Samavedam
, p. 900 - 902 (1998)
X-ray diffraction, high resolution transmission electron microscopy, and resistivity measurements were used to demonstrate a modification of the Ti/Si reaction path consisting of direct nucleation followed by diffusion limited growth of low resistivity C54 TiSi2 without nucleation of high resistivity C49 TiSi2, for the reaction of Ti with Mo doped polycrystalline or Mo doped amorphous Si by rapid thermal processing at 650 °C. We also report the mechanism of early C54 nucleation. We demonstrate that MoSi2 and an unidentified silicide phase lattice matched to C54 TiSi2, with spacings of 4.15 and 2.26 A, nucleate along the Ti/Si interface at early stages of the reaction and act as templates on which C54 TiSi2 nucleates and grows epitaxially. In contrast, the conventional phase sequence, nucleation and growth of C49 TiSi2 preceding nucleation of C54 TiSi2, was observed for the Ti/Mo doped single crystal (100) Si reaction and for all samples without Mo.
Twinning in TiSi2-island catalyzed Si nanowires grown by gas-source molecular-beam epitaxy
Tang, Qiang,Liu, Xian,Kamins, Theodore I.,Solomon, Glenn S.,Harris, James S.
, p. 2451 - 2453 (2002)
Using TiSi2 islands as a catalyst, we have grown Si nanowires by gas-source molecular-beam epitaxy using Si2H6 as the gas source. The dominant TiSi2 islands are C49 phase with the orientation: Si[110]//C49-TiSi2[100] and Si(001)//C49-TiSi 2(010). Twinning in the grown Si nanowires is observed by reflection high-energy electron diffraction and transmission electron microscopy. The twining also causes kinking, i.e., an abrupt change of growth direction of the Si nanowires. Lattice mismatch stress between the TiSi2 islands and the Si nanowires possibly leads to twinning and kinking of the Si nanowires.
TiSi2 selective growth in a rapid thermal low pressure chemical vapor deposition system
Bouteville,Remy,Attuyt
, p. 2260 - 2263 (1992)
The aim of this work is to selectively deposit titanium disilicide films on silicon area vs. silicon oxide area through a new commercial RTLPCVD apparatus. As a preliminary study, we tested our deposition system by using the well-known polysilicon deposition process. By this way, we showed that the temperature homogeneity on a 4 in. wafer is quite satisfying, and that the growth rates are about ten times higher than those obtained by using a standard hot wall LPCVD system. Then, we studied the titanium silicide deposition from either pure titanium tetrachloride or hydrogen-diluted titanium tetrachloride. As-deposited layers are well-adherent to the substrate and crystallized according to the C 54 structure. The resistivity ranges from 15-20 μΩ-cm and the selectivity on 8 μm wide lines never fails. An anomalous substrate silicon etching is observed when pure titanium chloride is used but we show that hydrogen dilution inhibits this unwanted phenomenon. Chemical reactions are proposed to explain the silicide deposition and the unwanted formation of gaseous silicon species leading to this anomalous silicon etching when pure titanium chloride is used.
XRD and XPS characterisation of transition metal silicide thin films
Tam,Cao,Nyborg
, p. 329 - 336 (2012)
Binary transition metal silicides based on the systems Ti-Si, Fe-Si, Ni-Si and Cr-Si were fabricated on Si wafers by means of ion-beam co-sputter deposition and subsequent annealing. The crystalline structures of the phases formed were identified from the characteristic patterns acquired by means of X-ray diffraction (XRD) measurements. The phase formation sequences were described by means of the Pretorius' effective heat of formation (EHF) model. For the Ti-Si, Fe-Si and Ni-Si systems, single phase thin films of TiSi 2, β-FeSi2 and NiSi2 were generated as the model predicts, while a mixture of CrSi + CrSi2 phases was obtained for the Cr-Si system. The surface chemical condition of individual specimens was analysed by using X-ray photoelectron spectroscopy (XPS). The chemical shifts of transition metal 2p3/2 peaks from their metallic to silicide states were depicted by means of the Auger parameters and the Wagner plots. The positive chemical shift of 2.0 eV for Ni 2p3/2 peak of NiSi 2 is mainly governed by the initial-state effects. For the other silicide specimens, the initial-state and final-state effects may oppose one another with similar impact. Consequently, smaller binding energy shifts of both negative and positive character are noted; a positive binding energy shift of 0.3 eV for the Fe 2p3/2 level was shown for β-FeSi2 and negative binding energy shifts of 0.1 and 0.3 eV were determined for CrSi + CrSi2 and TiSi2, respectively.
Reaction pathway of combustion synthesis of Ti5Si3 in Cu-Ti-Si system
Wang, Hui-Yuan,Lue, Si-Jie,Xiao, Wei,Liu, Guo-Jun,Wang, Jin-Guo,Jiang, Qi-Chuan
, p. 950 - 956 (2013)
The reaction pathway of combustion synthesis (CS) of Ti5Si 3 in Cu-Ti-Si system was explored through a delicate microstructure and phase analysis on the resultant products during differential thermal analysis (DTA). The formation of Cu-Si eutectic liquids plays a key role in the reaction pathway, which provides easy route for reactant transfer and accelerates the occurrence of complete reaction. Cu initially reacted with Si to form Cu3Si by a solid-state diffusion reaction, which further reacted with Cu to form Cu-Si liquids at the eutectic point of ~802°C; then Ti was dissolved into the surrounding Cu-Si liquids and led to the formation of Cu-Ti-Si ternary liquids; finally, Ti5Si3 was precipitated out of the saturated liquids by a solution-reaction-precipitation mechanism. The reaction pathway in CS of titanium silicide (Ti5Si3) could be described briefly as: Cu(s) + Ti(s) + Si (s)→Cu3Si(s) + Ti(s) + Si (s)→(Cu-Si)(l) + Ti(s)→(Cu-Ti-Si) (l)→Cu(l) + Ti5Si3(s).
CRYSTAL GROWTH, CHARACTERIZATION AND RESISTIVITY MEASUREMENTS OF TiSi2 SINGLE CRYSTALS.
Thomas,Madar,Senateur,Laborde
, p. 175 - 182 (1987)
Bulk single crystals of titanium disilicide TiSi//2 have been grown from a levitated melt with a modified cold crucible Czochralski method. The as-grown crystals were characterized by X-ray diffraction, density measurements and resistivity along the three main directions of the orthorhombic structure. TiSi//2 follows the classical behaviour of a metallic compound with a resistivity at room temperature near 10 mu OMEGA cm and a residual resistance ratio in the range 50 - 90.
Phase equilibria in the Dy-Ti-Si system at 1200 K
Morozkin
, p. 155 - 157 (2002)
Phase equilibria in the Dy-Ti-Si system were investigated by X-ray powder diffraction, local X-ray spectral analysis, metallographic analysis and the isothermal cross-section at 1200 K was obtained. The CeFeSi-type (space group P4/nmm, No. 129) DyTiSi compound has been confirmed. The new Sc2Re3Si4-type (space group P41212, No. 92) compound Dy2Ti3Si4 [a=0.6977(1) nm, c=1.2814(2) nm] was found. It is obvious that the AlB2-type (space group P6/mmm, No. 191) compound DyTi0.3Si1.7 [a=0.3824(1) nm, c=0.4119(1) nm] belongs to an extended region of the AlB2-type DySi1.56-based solid solution.
Optimized deposition parameters for low pressure chemical vapor deposited titanium silicide
Iiderem,Reif
, p. 2590 - 2596 (1988)
A system and a process have been developed for the low pressure chemical vapor deposition (LPCVD) of titanium silicide. The authors report for the first time the optimization of LPCVD titanium silicide film properties against the deposition parameters, including the temperature, pressure, and SiH4/TiCl4 flow rate ratios. Smooth, reproducible, low resistivity (15-20 μΩ-cm) titanium silicide films have been deposited at a temperature of 730°C, a pressure of 67 mtorr, and a SiH4/TiCl4 flow rate ratio of 20/2. The as-deposited films did not require any post-deposition annealing to achieve this low resistivity. All the as-deposited films had a Si/Ti metal ratio of about 2 (determined by Rutherford backscattering spectroscopy). Within the Auger detection limit, no contamination was observed in the silicide films, and the films had uniform composition except for a transition region between the titanium silicide and the underlying polysilicon layers.
Synthesis of Ti3SiC2 from powder blend of Ti, Si and TiC
Hashimoto, Hitoshi,Sun, Zheng Ming,Inoue, Yosuke,Tada, Shuji
, p. 263 - 267 (2006)
Titanium silicon carbide Ti3SiC2 was synthesized from a powder blend of Ti, Si and TiC at a molar ratio of Ti:Si:TiC = 2:2:3. The powder blend was pressed and shaped into a cylinder and then sintered at various temperatures in vacuum
