Isobutylgermane (IBGe, Chemical formula: (CH3)2CHCH2GeH3, is an organogermanium compound. It is a colourless, volatile liquid that is used in MOVPE (Metalorganic Vapor Phase Epitaxy) as an alternative to germane. IBGe is used in the deposition of Ge films and Ge-containing thin semiconductor films such as SiGe in strained silicon application, and GeSbTe in NAND Flash applications.

Isobutylgermane
Names
Preferred IUPAC name
(2-Methylpropyl)germane
Other names
Isobutylgermane
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.208.368 Edit this at Wikidata
EC Number
  • 682-844-5
  • InChI=1S/C4H12Ge/c1-4(2)3-5/h4H,3H2,1-2,5H3 checkY
    Key: PILXXBFWCYMNMX-UHFFFAOYSA-N checkY
  • InChI=1/C4H12Ge/c1-4(2)3-5/h4H,3H2,1-2,5H3
    Key: PILXXBFWCYMNMX-UHFFFAOYAD
  • CC(C)C[Ge]
Properties
C4H12Ge
Molar mass 132.78 g mol−1
Appearance Clear Colorless Liquid
Density 0.96 g/mL
Melting point < −78 °C (−108 °F; 195 K)
Boiling point 66 °C (151 °F; 339 K)
Insoluble in water
Related compounds
Related compounds
GeH4
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Properties

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IBGe is a non-pyrophoric liquid source for chemical vapor deposition (CVD) and atomic layer deposition (ALD) of semiconductors. It possesses very high vapor pressure and is considerably less hazardous than germane gas. IBGe also offers lower decomposition temperature (the onset of decomposition at ca. 325-350 °C).,[1] coupled with advantages of low carbon incorporation and reduced main group elemental impurities in epitaxially grown germanium comprising layers such as Ge, SiGe, SiGeC, strained silicon, GeSb, and GeSbTe.

Uses

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Rohm and Haas (now part of The Dow Chemical Company), IMEM, and CNRS have developed a process to grow germanium films on germanium at low temperatures in a Metalorganic Vapor Phase Epitaxy (MOVPE) reactor using isobutylgermane. The research targets Ge/III-V hetero devices.[2][3] It has been demonstrated that the growth of high quality germanium films at temperatures as low as 350 °C can be achieved.[4][5] The low growth temperature of 350 °C achievable with this new precursor has eliminated the memory effect of germanium in III-V materials. Recently IBGe is used to deposit Ge epitaxial films on a Si or Ge substrate Archived 2011-07-10 at the Wayback Machine, followed by the MOVPE deposition of InGaP and InGaAs layers with no memory effect, to enable triple-junction solar cells and integration of III-V compounds with silicon and germanium. It was demonstrated that isobutylgermane could be also used for the growth of germanium nanowires using gold as catalyst [6]

References

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  1. ^ Safer alternative liquid germanium precursors for relaxed graded SiGe layers and strained silicon by MOVPE[dead link]; D.V. Shenai et al., Presentation at ICMOVPE-XIII, Miyazaki, Japan, June 1, 2006, and publication in Journal of Crystal Growth (2007)
  2. ^ Woelk, Egbert; Shenai-Khatkhate, Deodatta V.; Dicarlo, Ronald L.; Amamchyan, Artashes; Power, Michael B.; Lamare, Bruno; Beaudoin, Grégoire; Sagnes, Isabelle (2006). "Designing novel organogermanium OMVPE precursors for high-purity germanium films". Journal of Crystal Growth. 287 (2): 684–687. Bibcode:2006JCrGr.287..684W. doi:10.1016/j.jcrysgro.2005.10.094.
  3. ^ Shenai-Khatkhate et al., Rohm and Haas Electronic Materials; Presentation at ACCGE-16, Montana, USA, July 11, 2005, and publication in Journal of Crystal Growth (2006)
  4. ^ MOVPE growth of homoepitaxial germanium, M. Bosi et al. publication in Journal of Crystal Growth (2008)
  5. ^ Homo and Hetero Epitaxy of Germanium Using Isobutylgermane, G. Attolini et al. publication in Thin Solid Films (2008)
  6. ^ Growth of germanium nanowires with isobuthyl germane, M. Bosi et al. publication in Nanotechnology (2019)

Further reading

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