Electrical Transport Properties of Hexagonal TaSi2 Crystals Based on Structural Stability under High Pressure
doi: 10.11858/gywlxb.20170571
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摘要: 作为一类稳定的低电阻及高温材料,二硅化钽(TaSi2)被广泛应用于集成电路中。因此,其电学稳定性和结构稳定性同样重要。报导了高压下六方TaSi2晶体基于结构稳定性的电学输运性质。通过同步辐射X射线衍射和拉曼光谱实验研究了TaSi2晶体在压力高达20 GPa时稳定的结晶学结构,并通过原位高压电阻测量发现,当压力增加到16.3 GPa时,TaSi2的电阻率趋于稳定在2 μΩ·cm左右;进一步理论计算了压力下TaSi2的电子结构,以进一步理解其金属性行为。Abstract: As a class of stable low-resistivity and high-temperature materials, tantalum disilicide (TaSi2) has been widely used in integrated circuits.Therefore, its electrical stability is as important as its structural stability.Here, we report the electronic transport properties of TaSi2 based on structural stability under high pressure.Its stable crystallographic structure was studied by synchrotron X-ray diffraction and Raman spectroscopy experiments up to 20 GPa.In situ high-pressure resistance measurements revealed that the resistivity of TaSi2 has a trend to be steady at the value of about 2 μΩ·cm under pressure increasing up to 16.3 GPa.Futher, the electronic structure of TaSi2 under pressure was theoretically calculated to understand its metallic behavior.
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Key words:
- TaSi2 /
- high pressure /
- crystal structure /
- electrical transport properties
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Table 1. Rietveld refinement results of TaSi2 under low pressure and high pressure
Pressure/GPa Atom type Fractional coordinates 1 Ta (0.5, 0, 0) 1 Si (0.16 148 66, 0.32 296 3, 0) 20 Ta (0.5, 0.32 296 30, 0) 20 Si (0.17 069 90, 0.34 138 9, 0) -
[1] SUBRAHMANYAM J, RAO R M.Combustion synthesis of MoSi2, WSi2 alloys[J]. Materials Science & Engineering A, 1994, 183(1/2):205-210. [2] ITO K, YANO T, NAKAMOTO T, et al.Microstructure and mechanical properties of MoSi2 single crystals and directionally solidified MoSi2-based alloys[J]. Progress in Materials Science, 1997, 42(1/2/3/4):193-207. http://www.osti.gov/scitech/biblio/5226139 [3] ITO K, NAKAMOTO T, INUI H, et al. Stacking faults on (001) in transition-metal disilicides with the cllb structure[C]//MRS Proceedings. Cambridge: Cambridge University Press, 1996, 460: 599. [4] HAO J, ZOU B, ZHU P W, et al.In situ X-ray observation of phase transitions in MgSi under high pressure[J]. Solid State Communications, 2009, 149(17):689-692. [5] SCHULTES G, SCHMITT M, GOETTEL D, et al.Strain sensitivity of TiB2, TiSi2, TaSi2 and WSi2 thin films as possible candidates for high temperature strain gauges[J]. Sensors & Actuators A:Physical, 2006, 126(2):287-291. [6] SCHMITT A L, HIGGINS J M, SZCZECH J R, et al.Synthesis and applications of metal silicide nanowires[J]. Journal of Materials Chemistry, 2009, 20(2):223-235. [7] JIANG D E, CARTER E A.First-principles study of the interfacial adhesion between SiO2 and MoSi2[J]. Physical Review B, 2005, 72(16):165410. doi: 10.1103/PhysRevB.72.165410 [8] LAVOIE C, D'HEURLE F M, DETAVERNIER C, et al.Towards implementation of a nickel silicide process for CMOS technologies[J]. Microelectronic Engineering, 2003, 70(2/3/4):144-157. [9] NAGASE T, YAMAUCHI I, OHNAKA I.Effect of rapid solidification on microstructure of various Fe29.5-xSi70.5-x (0.0≤x≤3.7) alloys[J]. Journal of Alloys & Compounds, 2000, 312(1):295-301. [10] ZHANG S L, ÖSTLING M. Metal silicides in CMOS technology:past, present, and future trends[J]. Critical Reviews in Solid State & Materials Sciences, 2003, 28(1):1-129. doi: 10.1080/10408430390802431?scroll=top&needAccess=true [11] LI C Y, YU Z H, LIU H Z, et al.High pressure and high temperature in situ X-ray diffraction study on the structural stability of tantalum disilicide[J]. Solid State Communications, 2013, 157:1-5. doi: 10.1016/j.ssc.2012.12.020 [12] KNOEDLER C M, DOUGLASS D H.Superconductivity in NbGe2, and isostructural C-40 compounds[J]. Journal of Low Temperature Physics, 1979, 37(1/2):189-218. http://www.osti.gov/scitech/biblio/6231613-superconductivity-nbge-sub-isostructural-compounds [13] GOTTLIEB U, LASJAUNIAS J C, THOLENCE J L, et al.Superconductivity in TaSi2 single crystals[J]. Physical Review B, 1992, 45(9):4803-4806. doi: 10.1103/PhysRevB.45.4803 [14] NAVA F, MAZZEGA E, MICHELINI M, et al.Analysis of the electrical resistivity of Ti, Mo, Ta, and W monocrystalline disilicides[J]. Journal of Applied Physics, 1989, 65(4):1584-1590. doi: 10.1063/1.342949 [15] ABU-SAMAHA F S, DARWISH A A A, MANSOUR A N.Temperature dependent of the current-voltage (I-V) characteristics of TaSi2 /n-Si structure[J]. Materials Science in Semiconductor Processing, 2013, 16(6):1988-1991. doi: 10.1016/j.mssp.2013.07.036 [16] MAO H K, XU J A, BELL P M.Calibration of the ruby pressure gauge to 800 kbar under quasi-hydrostatic conditions[J]. Journal of Geophysical Research:Solid Earth, 1986, 91(B5):4673-4676. doi: 10.1029/JB091iB05p04673 [17] HAMMERSLEY A P, SVENSSON S O, HANFLAND M, et al.Two-dimensional detector software:from real detector to idealised image or two-theta scan[J]. High Pressure Research, 1996, 14(4/5/6):14. [18] LARSON A C, VON DREELE R B. General structure analysis system (GSAS): LAUR 86-748[R]. USA: Los Alamos National Laboratory, 2004. [19] TOBY B H.EXPGUI, a graphical user interface for GSAS [J]. Journal of Applied Crystallography, 2001, 34(2):210-213. doi: 10.1107/S0021889801002242 [20] RAMADAN A A, GOULD R D, ASHOUR A.On the Van der Pauw method of resistivity measurements [J]. Thin Solid Films, 1994, 239(2):272-275. doi: 10.1016/0040-6090(94)90863-X [21] SEGALL M D, LINDAN P J D, PROBERT M J, et al.First-principles simulation:ideas, illustrations and the CASTEP code [J]. Journal of Physics:Condensed Matter, 2002, 14(11):2717-2744. doi: 10.1088/0953-8984/14/11/301 [22] KOSOBUTSKY A V, SARKISOV S Y, BRUDNYI V N.Structural, elastic and electronic properties of GaSe under biaxial and uniaxial compressive stress[J]. Journal of Physics & Chemistry of Solids, 2013, 74(9):1240-1248. https://www.sciencedirect.com/science/article/pii/S0022369713001480 [23] NAVA F, MAZZEGA E, MICHELINI M, et al.Analysis of the electrical resistivity of Ti, Mo, Ta, and W monocrystalline disilicides[J]. Journal of Applied Physics, 1989, 65(4):1584-1590. doi: 10.1063/1.342949