Atom-to-atom interactions for atomic layer deposition of trimethylaluminum on Ga-rich GaAs (001)-4 × 6 and As-rich GaAs(001)-2 × 4 surfaces: a synchrotron radiation photoemission study.

Autor: Tun-Wen Pi, Hsiao-Yu Lin, Ya-Ting Liu, Tsung-Da Lin, Wertheim, Gunther K., Jueinai Kwo, Minghwei Hong
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Zdroj: Nanoscale Research Letters; Apr2013, Issue 4, p1-7, 7p
Abstrakt: High-resolution synchrotron radiation photoemission was employed to study the effects of atomic-layer-deposited trimethylaluminum (TMA) and water on Ga-rich GaAs(001)-4 × 6 and As-rich GaAs(001)-2 × 4 surfaces. No high charge states were found in either As 3d or Ga 3d core-level spectra before and after the deposition of the precursors. TMA adsorption does not disrupt the GaAs surface structure. For the (4 × 6) surface, the TMA precursor existed in both chemisorbed and physisorbed forms. In the former, TMA has lost a methyl group and is bonded to the As of the As-Ga dimer. Upon water purge, the dimethylaluminum-As group was etched off, allowing the now exposed Ga to bond with oxygen. Water also changed the physisorbed TMA into the As-O-Al(CH3)2 configuration. This configuration was also found in 1 cycle of TMA and water exposure of the (2 × 4) surface, but with a greater strength, accounting for the high interface defect density in the mid-gap region. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index
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