Sulfide-passivated GaAs(001). I. Chemistry analysis by photoemission and reflectance anisotropy spectroscopies

Paget, D.; Bonnet, Jacques; Berkovits, V. L.; Chiaradia, P.; Ávila, J.

doi:10.1103/physrevb.53.4604

Cited by 62 publications

(48 citation statements)

References 36 publications

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“…8,22 It is worth pointing out that the exact nature of these states is still a matter of investigation with a number of different studies claiming varying assignments. [21][22][23][24][25] For example, while our assignment of As-H in this case is consistent with the binding energy position reported by Beerbom et al in Ref. 22, As-H itself would be unlikely to survive the elevated temperatures seen by the sample in the ALD reactor, and as such further work is needed to accurately identify the exact chemical composition of the peaks.…”

Section: Resultssupporting

confidence: 73%

Chemical and electrical characterization of the HfO2/InAlAs interface

Brennan

Galatage

Thomas

et al. 2013

Journal of Applied Physics

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InAlAs has the potential to be used as a barrier layer in buried channel quantum well field effect transistor devices due to favorable lattice-matching and carrier confinement properties with InGaAs. Field effect device structures of this nature may also require a high-k oxide deposited on the InAlAs surface to reduce leakage current. This study investigates the impact of surface preparations and atomic layer deposition of HfO2 on these surfaces using x-ray photoelectron spectroscopy to analyse the chemical interactions taking place, as well as the electrical performance of associated capacitor devices. A large concentration of As related surface features is observed at the InAlAs surface, and is attributed to a large D-it response in electrical measurements. (C) 2013 AIP Publishing LLC

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Section: Resultssupporting

confidence: 73%

Chemical and electrical characterization of the HfO2/InAlAs interface

Brennan

Galatage

Thomas

et al. 2013

Journal of Applied Physics

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“…Figure 13.7d shows that two S atoms form a S-S dimer pair with a dimer bond length of 2.11 A and that the dimer forms two bonds with two dangling As atoms. With the presence of S-S dimer pair and SÀAs bonds, this surface model is consistent with experimental observations [9]. Figure 13.7e indicates one S atom interacting with a specific As atom with a dangling bond.…”

Section: Passivation Of the Oxidized Gaas Surfacesupporting

confidence: 76%

“…The Si/SiO 2 interface has low gap states due to the nature of tetrahedral covalent bonding of Si and SiO 2 in which dangling Si bonds are easily passivated by H [9]. But high-k oxides such as HfO 2 and Al 2 O 3 have ionic bonding without a fixed coordination number, resulting in poor interface bonding quality because of the intrinsic complexity of high k/III-V.…”

mentioning

confidence: 99%

Theoretical Progress on GaAs (001) Surface and GaAs/High‐ k Interface

Wang

Xiong

Wallace

et al. 2012

High‐k Gate Dielectrics for CMOS Technology

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The recent resurgence of interest in III-V transistor channel materials has come about due to the scaling requirement of Si-based metal oxide semiconductor (MOS) devices [1]. III-V channel materials have much higher bulk electron mobilities than Si (see Table 13.1) and thus expected to provide high channel injection velocities. Among the III-V compounds, gallium arsenide (GaAs) is a prototype material because of its many advantages, such as, 5Â higher electron mobility than Si, the availability of semiinsulating GaAs substrates, and a higher breakdown field over Si to achieve GaAs-based high-speed devices.Nevertheless, III-V materials suffer from a lack of thermodynamically stable gate dielectrics [2], with an acceptable low density of III-V/dielectric interface states, which makes it very difficult to be implemented into future CMOS-type devices. The interfacial density of states (D it ) leads to many problems such as Fermi-level pinning, reduced electron mobility, and instability of device operations. The Fermi-level pinning results in the loss of the modulation of the carrier concentration at the oxide/III-V interface by the gate bias. For oxide/III-V interfaces, the interfacial group III-or V-dangling bonds are partially saturated [3] and they can hardly be fully saturated to obtain a superior high-k/III-V interface with low D it . Furthermore, the partially saturated bonds can induce mid-gap states that lead to Fermi-level pinning. This pinning is most likely due to the presence of III(V)-O bonds and the resultant structural disorders. Therefore, understanding the oxidation and passivation mechanisms of the III-V surface are very useful to gain an important insight to control the quality of high-k/III-V interfaces [4][5][6][7][8].When high-k oxides are deposited upon III-V materials, the III-V/high-k oxide interfaces are much more complicated than the ideal III-V surface alone. The low electronic quality of an III-V/dielectric interface can be attributed to several reasons.High-k Gate Dielectrics for CMOS Technology, First Edition. Edited by Gang He and Zhaoqi Sun.

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“…With the presence of S-S dimer pairs and S-As bonds, our surface model is consistent with experiment observations. 32 Fig. 10͑e͒ indicates one S atom interacting with the specific As atom with dangling bond.…”

Section: Atomic Structures Of Passivation Of Oxidized Gaas"001…-␤2"2 mentioning

confidence: 99%

First-principles study of GaAs(001)-β2(2×4) surface oxidation and passivation with H, Cl, S, F, and GaO

Wang

Lee

Huang

et al. 2010

Journal of Applied Physics

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The interactions of oxygen atoms on the GaAs(001)-β2(2×4) surface and the passivation of oxidized GaAs(001)-β2(2×4) surface were studied by density functional theory. The results indicate that oxygen atoms adsorbed at back-bond sites satisfy the bond saturation conditions and do not induce surface gap states. However, due to the oxygen replacement of an As dimer atom at a trough site or row site, the As–As bond is broken, and gap states are produced leading to the Fermi level pinning because of unsaturated As dangling bonds. Atomic H, Cl, S, F, and the molecular species GaO were examined to passivate the unsaturated As dangling bond. The results show that H, Cl, F, and GaO can remove such gap states. It is also found that the interaction of S with the unsaturated As dangling bond does not remove the gap states, and new gap states are generated upon single S adsorption. A higher S coverage forms S–S dimer pairs which passivate two unsaturated As atoms, and removes the As-induced gap states.

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Sulfide-passivated GaAs(001). I. Chemistry analysis by photoemission and reflectance anisotropy spectroscopies

Cited by 62 publications

References 36 publications

Chemical and electrical characterization of the HfO2/InAlAs interface

Chemical and electrical characterization of the HfO2/InAlAs interface

Theoretical Progress on GaAs (001) Surface and GaAs/High‐ k Interface

First-principles study of GaAs(001)-β2(2×4) surface oxidation and passivation with H, Cl, S, F, and GaO

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