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.
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| Names | |
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| Preferred IUPAC name
(2-Methylpropyl)germane | |
| Other names
Isobutylgermane
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| Identifiers | |
3D model (JSmol)
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| ChemSpider | |
| ECHA InfoCard | 100.208.368 |
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PubChem CID
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CompTox Dashboard (EPA)
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| 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
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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 edit
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 edit
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, 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 edit
- ^ 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)
- ^ 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.
- ^ 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)
- ^ MOVPE growth of homoepitaxial germanium, M. Bosi et al. publication in Journal of Crystal Growth (2008)
- ^ Homo and Hetero Epitaxy of Germanium Using Isobutylgermane, G. Attolini et al. publication in Thin Solid Films (2008)
- ^ Growth of germanium nanowires with isobuthyl germane, M. Bosi et al. publication in Nanotechnology (2019)
Further reading edit
- IBGe: Brief description from National Compound Semiconductor Roadmap.
- Élaboration et Physique des Structures Épitaxiées (LPN) Hétérostructures III-V pour l’optoélectronique sur Si: Article in French from LPN-CNRS, France.
- Designing Novel Organogermanium OMVPE Precursors for High-purity Germanium Films[permanent dead link]; Journal of Crystal Growth, January 25, 2006.
- Ge Precursors for Strained Si and Compound Semiconductors; Semiconductor International, April 1, 2006.
- Development of New Germanium Precursors for SiGe Epitaxy; Deo Shenai and Egbert Woelk, Presentation at 210th ECS Meeting, Cancun, Mexico, October 29, 2006.