X-ray Photoelectron Spectroscopic Studies of Sulphur-passivated GaAsSurfaces

Wang, Xun; Hou, Xiaoyuan; Li, Zhe-Shen; Chen, Xiying

doi:10.1002/(sici)1096-9918(19960916)24:9<564::aid-sia148>3.0.co;2-1

Cited by 8 publications

(6 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The steps necessary to achieve full covalent bonding are suggested in Figure C. Preferential alignment of adsorbates along the [10] step edge direction of GaAs(001) has been observed for many systems including C 60 , and various chalcogenides. , The scanning tunneling microscopy observation that the step edges on the (001) surface run parallel to this direction imply that the high energy step edge atoms are the preferred initial binding sites of adsorbate molecules.…”

Section: Resultsmentioning

confidence: 99%

Molecular Self-Assembly at Bare Semiconductor Surfaces: Characterization of a Homologous Series of n-Alkanethiolate Monolayers on GaAs(001)

et al. 2007

View full text Add to dashboard Cite

Structural trends for a homologous series of n-alkanethiolate self-assembled monolayers (SAMs), C(n)H(2n+1)S- with 12 < or = n < or = 19, on GaAs(001), studied by a combination of grazing incidence X-ray diffraction and infrared spectroscopy, along with ancillary probes, show an overall decay in organization with decreasing n, with the largest changes occurring below n = 15-16. The long-chain monolayers form a mosaic structure with < or =10 nm domains of molecules organized in an incommensurate pseudo-hcp arrangement with nearest neighbor distances of 4.70 and 5.02 A, a 21.2 A(2) area per chain, two chains per subcell in a herringbone packing with a chain tilt angle of 14 degrees , and preferential domain alignment along the substrate [110]([110]) step edge direction. In contrast, for n < 14 no evidence of translational ordering is seen and the alkyl chains exhibit a loss of conformational ordering and coverage relative to the n > 16 cases. A 4'-methyl-biphenyl-4-thiolate companion SAM shows evidence for ordered structures but with lattice parameters close to those expected for a structure commensurate with the intrinsic GaAs(001) square lattice. These trends are explained on the basis of competitions between lattice, interfacial, and intermolecular forces controlling the nanoscale structures of the SAMs. Overall these results provide an important aspect of understanding the effects of SAM formation on surface properties such as electronic and chemical passivation.

show abstract

Section: Resultsmentioning

confidence: 99%

Molecular Self-Assembly at Bare Semiconductor Surfaces: Characterization of a Homologous Series of n-Alkanethiolate Monolayers on GaAs(001)

et al. 2007

View full text Add to dashboard Cite

show abstract

“…A number of sulfur-based processes, including aqueous and gas-phase treatments, have been investigated to enhance the resistance of GaAs to oxidation. Wet chemical treatments including ammonium sulfide ((NH 4 ) 2 S), − sodium sulfide (Na 2 S·9H 2 O), − thionyl chloride (SO 2 Cl 2 ), − thioacetamide (CH 3 CSNH 2 ), − and organothiols − have all been shown to generate passivating layers on GaAs surfaces with varying degrees of success. Among these compounds, (NH 4 ) 2 S has been shown to be the most effective; however, even samples treated by this method have shown degradation upon exposure to the atmosphere.…”

Section: Introductionmentioning

confidence: 99%

Surface Reactions of 1-Propanethiol on GaAs(100)

et al. 2005

View full text Add to dashboard Cite

The adsorption and decomposition pathways of 1-propanethiol on a Ga-rich GaAs(100) surface have been investigated using the techniques of temperature programmed desorption, X-ray photoelectron spectroscopy (XPS), and time-of-flight secondary ion mass spectrometry (TOF-SIMS). 1-Propanethiol adsorbs dissociatively on a clean GaAs(100) surface to form propanethiolate and hydrogen. Further reactions of these species to form new products compete with the recombinative desorption of molecular propanethiol. The C-S bond scission in the propanethiolate results in the formation of propyl species and elemental sulfur. The generation of propene via beta-hydride elimination then follows. In addition, propane and hydrogen form via reductive elimination processes. A recombinative high-temperature propanethiol desorption state is also observed. XPS and TOF-SIMS analyses confirm the presence of sulfur on the GaAs(100) surface following thermal decomposition. This paper discusses the mechanisms by which these products form on the GaAs(100) surface.

show abstract

Section: Introductionmentioning

confidence: 99%

“…Different S containing materials were applied to achieve a S passivation of the GaAs͑100͒ surface, such as ͑NH 4 ͒ 2 S x , 1,2 S 2 Cl 2 , 3,4 and Na 2 S 5 in aqueous solutions but also in alcoholic solutions. 3,4,7 Today there is hardly any comparative study dealing with the sulfur modification of n-and p-doped GaAs͑100͒ surfaces, which is important for the understanding the passivating properties of sulfur on GaAs͑100͒. 7 Different methods were applied to investigate the properties of the S passivated GaAs͑100͒ surfaces like scanning tunneling microscopy ͑STM͒, 7 low-energy electron diffraction ͑LEED͒, 7 reflection high-energy electron diffraction ͑RHEED͒, 2 photoluminescence ͑PL͒ measurements, 6 x-ray photoelectron spectroscopy ͑XPS͒, 1-4,6,7 and Auger electron spectroscopy ͑AES͒.…”

Section: Introductionmentioning

confidence: 99%

Influence of sulfur interlayers on the Mg/GaAs(100) interface formation

Hohenecker

Kampen

Zahn

et al. 1998

Journal of Vacuum Science &Amp; Technology B: Microelectronics and Nanometer Structures Processing, Measurement, and Phenomena

View full text Add to dashboard Cite

The modification of clean GaAs͑100͒ surfaces by in situ deposition of molecular sulfur was investigated by soft x-ray photoemission spectroscopy. Upon S treatment of the clean GaAs͑100͒ sample at 435-455°C in ultrahigh vacuum the formation of a three monolayer thick gallium sulfide-like compound is observed, which exhibits a ͑2ϫ1͒ low-energy electron diffraction pattern. Due to the S modification on n-GaAs a reduction of the band bending by 0.35 eV is achieved, while the band bending on p-GaAs is increased by 0.17 eV. The subsequent Mg evaporation leads to the formation of a metal/semiconductor contact with a reacted magnesium sulfide-like compound at the interface. After 1 nm Mg deposition the Schottky barrier height of the S-modified Mg/n-GaAs(100) contact amounts to 0.44 eV, which is 0.18 eV lower than without S modification, while the Mg/p-GaAs͑100͒ Schottky contact exhibits an increase in the Schottky barrier height by 0.30 eV in comparison to the value of the unmodified Schottky contact ͑0.55 eV͒.

show abstract

X-ray Photoelectron Spectroscopic Studies of Sulphur-passivated GaAsSurfaces

Cited by 8 publications

References 1 publication

Molecular Self-Assembly at Bare Semiconductor Surfaces: Characterization of a Homologous Series of n-Alkanethiolate Monolayers on GaAs(001)

Molecular Self-Assembly at Bare Semiconductor Surfaces: Characterization of a Homologous Series of n-Alkanethiolate Monolayers on GaAs(001)

Surface Reactions of 1-Propanethiol on GaAs(100)

Influence of sulfur interlayers on the Mg/GaAs(100) interface formation

Contact Info

Product

Resources

About