Growth of GaS on GaAs(100)-(4×2) with the single-source precursor [( tBu)GaS] 4

• Published in: Surface science 2000-02, Vol.446 (1), p.55-62
• Main Authors: Hopcus, A.B., Yi, S.I., Chung, C.-H., Pelzel, R.I., Weinberg, W.H.
• Format: Article
• Language: English
• Subjects: Chemical vapor deposition (including plasma-enhanced cvd, mocvd, etc.); Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Gallium arsenide; Gallium sulfide; III–VI compounds; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; MOCVD; Physics; Single-source precursor; Surface passivation
• ISSN: 0039-6028; 1879-2758
• DOI: 10.1016/S0039-6028(99)01090-0

The growth of a GaS film on the GaAs(100)-(4×2) surface, using [( tBu)GaS] 4, has been studied in ultra-high vacuum using high-resolution electron energy loss spectroscopy (HREELS), Auger electron spectroscopy (AES), low-energy electron diffraction (LEED), and temperature-programmed desorption (TPD). Upon the adsorption of a monolayer of GaS, we observed the formation of a (2×1) superstructure, as evidenced by LEED. For multilayer growth at 650 K, a (1×1) LEED pattern was observed. For submonolayer coverages of the precursor adsorbed at 100 K, thermally induced β-hydrogen elimination of the tert-butyl ligands was observed at 650 K, as evidenced by concurrent desorption of isobutene and molecular hydrogen. An amorphous GaS film is formed after multilayer adsorption of [( tBu)GaS] 4 at 100 K, followed by annealing to 650 K. However, isobutane, isobutene, and molecular hydrogen desorption is seen from such a surface, suggesting an additional tert-butyl ligand removal pathway. Finally, layer-by-layer growth of a GaS film was achieved by a cyclic process of monolayer adsorption of [( tBu)GaS] 4 at 200 K, followed by annealing to 700 K.