Nickel monosilicide

Last updated
NiSi
FeB structure 2.png
Identifiers
3D model (JSmol)
ChemSpider
PubChem CID
  • InChI=1S/Ni.Si
    Key: PEUPIGGLJVUNEU-UHFFFAOYSA-N
  • [Si].[Ni]
Properties
NiSi
Molar mass 86.778 g/mol
Melting point 1,000 °C; 1,832 °F; 1,273 K [1]
−0.3×10−6 emu/g [2]
Structure [3]
Orthorhombic, oP8
Pnma, No. 62
a = 0.519 nm, b = 0.333 nm, c = 0.5628 nm
4
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Nickel monosilicide is an intermetallic compound formed out of nickel and silicon. Like other nickel silicides, NiSi is of importance in the area of microelectronics.

Contents

Preparation

Nickel monosilicide can be prepared by depositing a nickel layer on silicon and subsequent annealing. In the case of Ni films with thicknesses above 4  nm, the normal phase transition is given by Ni2Si at 250 °C followed by NiSi at 350 °C and NiSi2 at approximately 800 °C. [4] For films with an initial Ni thickness below 4 nm a direct transition from orthorhombic Ni2Si to epitaxial NiSi2−x, skipping the nickel monosilicide phase, is observed. [5]

Uses

Several properties make NiSi an important local contact material in the area of microelectronics, among them a reduced thermal budget, low resistivity of 13–14 μΩ·cm and a reduced Si consumption when compared to alternative compounds. [6]

Related Research Articles

<span class="mw-page-title-main">Epitaxy</span> Crystal growth process relative to the substrate

Epitaxy refers to a type of crystal growth or material deposition in which new crystalline layers are formed with one or more well-defined orientations with respect to the crystalline seed layer. The deposited crystalline film is called an epitaxial film or epitaxial layer. The relative orientation(s) of the epitaxial layer to the seed layer is defined in terms of the orientation of the crystal lattice of each material. For most epitaxial growths, the new layer is usually crystalline and each crystallographic domain of the overlayer must have a well-defined orientation relative to the substrate crystal structure. Epitaxy can involve single-crystal structures, although grain-to-grain epitaxy has been observed in granular films. For most technological applications, single-domain epitaxy, which is the growth of an overlayer crystal with one well-defined orientation with respect to the substrate crystal, is preferred. Epitaxy can also play an important role while growing superlattice structures.

<span class="mw-page-title-main">Intermetallic</span> Type of metallic alloy

An intermetallic is a type of metallic alloy that forms an ordered solid-state compound between two or more metallic elements. Intermetallics are generally hard and brittle, with good high-temperature mechanical properties. They can be classified as stoichiometric or nonstoichiometic intermetallic compounds.

<span class="mw-page-title-main">Silicide</span> Chemical compound that combines silicon and a more electropositive element

A silicide is a type of chemical compound that combines silicon and a usually more electropositive element.

<span class="mw-page-title-main">Platinum silicide</span> Chemical compound

Platinum silicide, also known as platinum monosilicide, is the inorganic compound with the formula PtSi. It is a semiconductor that turns into a superconductor when cooled to 0.8 K.

<span class="mw-page-title-main">Molybdenum disilicide</span> Chemical compound

Molybdenum disilicide (MoSi2, or molybdenum silicide), an intermetallic compound, a silicide of molybdenum, is a refractory ceramic with primary use in heating elements. It has moderate density, melting point 2030 °C, and is electrically conductive. At high temperatures it forms a passivation layer of silicon dioxide, protecting it from further oxidation. The thermal stability of MoSi2 alongside its high emissivity make this material, alongside WSi2 attractive for applications as a high emissivity coatings in heat shields for atmospheric entry. MoSi2 is a gray metallic-looking material with tetragonal crystal structure (alpha-modification); its beta-modification is hexagonal and unstable. It is insoluble in most acids but soluble in nitric acid and hydrofluoric acid.

The term salicide refers to a technology used in the microelectronics industry used to form electrical contacts between the semiconductor device and the supporting interconnect structure. The salicide process involves the reaction of a metal thin film with silicon in the active regions of the device, ultimately forming a metal silicide contact through a series of annealing and/or etch processes. The term "salicide" is a compaction of the phrase self-aligned silicide. The description "self-aligned" suggests that the contact formation does not require photolithography patterning processes, as opposed to a non-aligned technology such as polycide.

<span class="mw-page-title-main">Calcium disilicide</span> Chemical compound

Calcium disilicide (CaSi2) is an inorganic compound, a silicide of calcium. It is a whitish or dark grey to black solid matter with melting point 1033 °C. It is insoluble in water, but may decompose when subjected to moisture, evolving hydrogen and producing calcium hydroxide. It decomposes in hot water, and is flammable and may ignite spontaneously in air.

<span class="mw-page-title-main">Eutectic bonding</span>

Eutectic bonding, also referred to as eutectic soldering, describes a wafer bonding technique with an intermediate metal layer that can produce a eutectic system. Those eutectic metals are alloys that transform directly from solid to liquid state, or vice versa from liquid to solid state, at a specific composition and temperature without passing a two-phase equilibrium, i.e. liquid and solid state. The fact that the eutectic temperature can be much lower than the melting temperature of the two or more pure elements can be important in eutectic bonding.

<span class="mw-page-title-main">Binary compounds of silicon</span> Any binary chemical compound containing just silicon and another chemical element

Binary compounds of silicon are binary chemical compounds containing silicon and one other chemical element. Technically the term silicide is reserved for any compounds containing silicon bonded to a more electropositive element. Binary silicon compounds can be grouped into several classes. Saltlike silicides are formed with the electropositive s-block metals. Covalent silicides and silicon compounds occur with hydrogen and the elements in groups 10 to 17.

Chromium(II) silicide or chromium disilicide is an inorganic compound of chromium and silicon. Its chemical formula is CrSi2. It is a p-type thermoelectric semiconductor with an indirect bandgap of 0.35 eV.

Nickel compounds are chemical compounds containing the element nickel which is a member of the group 10 of the periodic table. Most compounds in the group have an oxidation state of +2. Nickel is classified as a transition metal with nickel(II) having much chemical behaviour in common with iron(II) and cobalt(II). Many salts of nickel(II) are isomorphous with salts of magnesium due to the ionic radii of the cations being almost the same. Nickel forms many coordination complexes. Nickel tetracarbonyl was the first pure metal carbonyl produced, and is unusual in its volatility. Metalloproteins containing nickel are found in biological systems.

<span class="mw-page-title-main">Nickel silicide</span> Chemical compound

Nickel silicides include several intermetallic compounds of nickel and silicon. Nickel silicides are important in microelectronics as they form at junctions of nickel and silicon. Additionally thin layers of nickel silicides may have application in imparting surface resistance to nickel alloys.

Iron disilicide (FeSi2) is an intermetallic compound, a silicide of iron that occurs in nature as the rare mineral linzhiite. At room temperature it forms orthorhombic crystals (β phase), which convert into a tetragonal α phase upon heating to 970 °C.

<span class="mw-page-title-main">Iron monosilicide</span> Chemical compound

Iron monosilicide (FeSi) is an intermetallic compound, a silicide of iron that occurs in nature as the rare mineral naquite. It is a narrow-bandgap semiconductor with a room-temperature electrical resistivity of around 10 kΩ·cm and unusual magnetic properties at low temperatures. FeSi has a cubic crystal lattice with no inversion center; therefore its magnetic structure is helical, with right-hand and left-handed chiralities.

<span class="mw-page-title-main">Cobalt disilicide</span> Chemical compound

Cobalt disilicide (CoSi2) is an intermetallic compound, a silicide of cobalt. It is a superconductor with a transition temperature of around 1.4 K and a critical field of 105 Oe.

<span class="mw-page-title-main">Cobalt monosilicide</span> Chemical compound

Cobalt monosilicide (CoSi) is an intermetallic compound, a silicide of cobalt. It is a diamagnetic semimetal with an electrical resistivity of around 1 mΩ·cm.

<span class="mw-page-title-main">Manganese disilicide</span> Chemical compound

Manganese disilicide (MnSi2) is an intermetallic compound, a silicide of manganese. It is a non-stoichiometric compound, with a silicon deficiency expressed as MnSi2–x. Crystal structures of many MnSi2–x compounds resemble a chimney ladder and are called Nowotny phases. They include MnSi2 (x=0), Mn4Si7 (x=0.250), Mn11Si19 (x=0.273), Mn15Si26 (x=0.267) and Mn27Si47 (x=0.259). These phases have very similar unit cells whose length varies from 1.75 nm for MnSi2 or Mn4Si7, which have almost the same structures, to 11.8 nm for Mn27Si47.

<span class="mw-page-title-main">Manganese monosilicide</span> Chemical compound

Manganese monosilicide (MnSi) is an intermetallic compound, a silicide of manganese. It occurs in cosmic dust as the mineral brownleeite. MnSi has a cubic crystal lattice with no inversion center; therefore its crystal structure is helical, with right-hand and left-hand chiralities.

Chromium(IV) silicide or chromium monosilicide is an inorganic compound of chromium and silicon with a chemical formula of CrSi. It is a metal with an electrical resistivity of ca. 2×10−4 Ω·cm.

Plutonium silicide is a binary inorganic compound of plutonium and silicon with the chemical formula PuSi. The compound forms gray crystals.

References

  1. Gas, P.; d’Heurle, F. M. (1998). "Diffusion in silicides". In Beke, D. L. (ed.). Landolt-Börnstein - Group III Condensed Matter. Vol. 33A. Springer. pp. 1–38. doi:10.1007/10426818_13. ISBN   3-540-60964-4.
  2. Shinoda, Daizaburo; Asanabe, Sizuo (1966). "Magnetic Properties of Silicides of Iron Group Transition Elements". Journal of the Physical Society of Japan. 21 (3): 555. Bibcode:1966JPSJ...21..555S. doi:10.1143/JPSJ.21.555.
  3. Wopersnow W., Schubert K. (1976) Z. Metallkd., 67, 807–810
  4. d'Heurle, F. M.; Gas, P. (February 1986). "Kinetics of formation of silicides: A review". Journal of Materials Research. 1 (1): 205–221. Bibcode:1986JMatR...1..205D. doi:10.1557/JMR.1986.0205. S2CID   135724287.
  5. Wolf, Philipp M.; Pitthan, Eduardo; Zhang, Zhen; Lavoie, Christian; Tran, Tuan T.; Primetzhofer, Daniel (2022-02-21). "Direct Transition from Ultrathin Orthorhombic Dinickel Silicides to Epitaxial Nickel Disilicide Revealed by In Situ Synthesis and Analysis". Small. 18 (14): 2106093. doi: 10.1002/smll.202106093 . ISSN   1613-6810. PMID   35191181. S2CID   247023770.
  6. Lavoie, C.; d’Heurle, F.M.; Detavernier, C.; Cabral, C. (November 2003). "Towards implementation of a nickel silicide process for CMOS technologies". Microelectronic Engineering. 70 (2–4): 144–157. doi:10.1016/S0167-9317(03)00380-0.