Arsenic-rich GaAs(0 0 1) surface structure

LaBella, V. P.; Krause, Michael; Ding, Zhao; Thibado, P. M.

doi:10.1016/j.surfrep.2005.10.001

Cited by 84 publications

(44 citation statements)

References 187 publications

(319 reference statements)

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“…Therefore, this model (Ref. [12]) is consistent with the experimental findings [20,21] and provides an important insight into the nature of Si-passivation at high-k/III-V interfaces.…”

Section: 43supporting

confidence: 84%

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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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“…Therefore, this model (Ref. [12]) is consistent with the experimental findings [20,21] and provides an important insight into the nature of Si-passivation at high-k/III-V interfaces.…”

Section: 43supporting

confidence: 84%

“…Finally, there are other scattering mechanisms, such as phonon scattering [10], surface roughness scattering [11], and so on, to influence the carrier transport. The GaAs(001) surface is the most intensively studied system among all III-V materials [18][19][20]. It consists of alternating planes of Ga and As that are separated by 1.41 A [19].…”

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 GaAs(001) surface figures prominently in a number of GaAs thin-film applications and has been the subject of many studies, as is discussed in some recent reviews. [14][15][16] In typical MBE growth settings for homoepitaxy, the GaAs(001) substrate exhibits the As-rich β2(2×4) surface reconstruction. 15,16 Although the structure of the β2(2×4) unit cell has been well established experimentally [17][18][19][20][21][22][23][24] and theoretically, [25][26][27][28][29] Pashley and colleagues have pointed out that the twofold structural degeneracy of the β2(2 × 4) unit cell can lead to β2 (2 × 4) surfaces that have a long-range disorder associated with occupancy of out-of-phase unit cells.…”

Section: Introductionmentioning

confidence: 99%

Analytic many-body potential for GaAs(001) homoepitaxy: Bulk and surface properties

et al. 2011

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We employ atomic-scale simulation methods to investigate bulk and surface properties of an analytic TersoffAbell type potential for describing interatomic interactions in GaAs. The potential is a modified form of that proposed by Albe and colleagues [Phys. Rev. B 66, 035205 (2002)] in which the cut-off parameters for the As-As interaction have been shortened. With this modification, many bulk properties predicted by the potential for solid GaAs are the same as those in the original potential, but properties of the GaAs(001) surface better match results from first-principles calculations with density-functional theory (DFT). We tested the ability of the potential to reproduce the phonon dispersion and heat capacity of bulk solid GaAs by comparing it to experiment and the overall agreement is good. In the modified potential, the GaAs(001) β2(2 × 4) reconstruction is favored under As-rich growth conditions in agreement with DFT calculations. Additionally, the binding energies and diffusion barriers for a Ga adatom on the β2(2 × 4) reconstruction generally match results from DFT calculations. These studies indicate that the potential is suitable for investigating aspects of GaAs(001) homoepitaxy.

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“…[3][4][5] It consists of alternating planes of Ga and As that are separated by 1.41 Å. 5 Both Ga-terminated and As-terminated GaAs͑001͒ surfaces were observed to reconstruct forming As-As dimers or Ga-Ga dimers on the surface. 6 The oxidation and passivation of a GaAs͑001͒ surface are important issues of GaAs-based MOSFETS, thus of great interest to researchers.…”

Section: Introductionmentioning

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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Arsenic-rich GaAs(0 0 1) surface structure

Cited by 84 publications

References 187 publications

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

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

Analytic many-body potential for GaAs(001) homoepitaxy: Bulk and surface properties

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

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