Mechanism of carbon incorporation during GaAs epitaxy

Creighton, J. R.; Bansenauer, Barbara A.; Huett, T.; White, J. M.

doi:10.1116/1.578320

Cited by 25 publications

(14 citation statements)

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“…Additionally, the TMG and TMSb may dissociatively adsorb on the substrate surface to yield the adsorbed MMG and MMSb as given in Eqs. (8) and (9):…”

Section: Article In Pressmentioning

confidence: 99%

“…The use of an organic, as opposed to hydride, source can also impact the purity of the resulting film. Group V hydrides have been shown to heterogeneously decompose readily at MOVPE growth temperatures and to serve as a source of active hydrogen which participates in the removal of carbon-based species from the growth surface reducing the background carbon incorporation [6][7][8].…”

Section: Introductionmentioning

confidence: 99%

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Growth behavior of GaSb by metal–organic vapor-phase epitaxy

Rathi

Hawkins

Kuech

2006

Journal of Crystal Growth

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“…Additionally, the TMG and TMSb may dissociatively adsorb on the substrate surface to yield the adsorbed MMG and MMSb as given in Eqs. (8) and (9):…”

Section: Article In Pressmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Growth behavior of GaSb by metal–organic vapor-phase epitaxy

Rathi

Hawkins

Kuech

2006

Journal of Crystal Growth

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“…4,61 At 450°C methyl groups start to be removed from the surface. 62 Our calculations suggest that the desorption will lead directly Tables 3 and 4. (5) -0.55 a Asterisk indicates gallium insertion into the arsenic dimer, and numbers in parentheses refer to the configuration labeled in Figure 12.…”

Section: Dft Calculationsmentioning

confidence: 96%

The GaAs(001)-(2 × 4) Surface: Structure, Chemistry, and Adsorbates

Goringe¹,

Clark

Lee

et al. 1997

J. Phys. Chem. B

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A series of ab initio simulations, based on density functional theory, of the structure of the clean GaAs-(001)-(2 × 4) surface and of C 2 H 2 , C 2 H 4 , and trimethylgallium (TMGa) adsorbates are described. This surface was selected because of its importance in the growth of GaAs by molecular beam epitaxy. After summarizing briefly the theoretical basis of the computational methods used in the paper, we review critically what is known from experiment and theory about the structure of the clean surface. We argue that there is now strong evidence in favor of the "trench dimer" model for the -phase of the clean surface, while the structures of the R and γ phases are less settled. We then present ab initio simulations of the trench dimer, the three dimer, and the gallium rebonded models of the clean GaAs(001)-(2 × 4) surface and discuss their common structural and bonding features. Ab initio simulations of C 2 H 2 and C 2 H 4 adsorbates at arsenic dimers of the GaAs(001)-(2 × 4) surface are then presented. The changes in the bonding configurations of both the adsorbates and the surface arsenic dimers are explained in terms of changes in the bond orders and local hybridization states. The As dimer bond is broken in the stable chemisorbed states of the molecules. However, an intermediate state, in which the As dimer is still intact, provides a significant barrier to chemisorption in both cases. This barrier, and its absence at the Si(001) surface, stems from the two extra electrons in the As dimer compared with the Si dimer. We then go on to describe the results of 14 ab initio simulations of structures connected with the chemisorption and decomposition of TMGa on the GaAs(001)-(2 × 4) surface. TMGa is commonly used in the growth of GaAs crystals from the vapor phase. The results of these simulations are used to explain a number of experimental observations concerning the surface coverage and the decomposition of TMGa to dimethylgallium and monomethylgallium. Significant technical aspects of the calculations, notably the number of relaxed layers in the slab calculations and the necessity to use gradient-corrected adsorption energies, are stressed. The paper also contains critical comments about ab initio simulations of the GaAs-(001)-(2 × 4) clean surface and about the model based on a "linear combination of structural motifs".

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“…Later, Leys and Veenvliet [5] proposed that decomposition of the metal-organic reactants take place in the gas phase and that gallium atoms, gallium arsenide molecules or clusters thereof diffuse towards the surface. More recent models [6][7][8] suggest that it is likely a combination of these two mechanisms that occur; partial pyrolysis of the reactants in the gas phase while they are diffusing towards the surface, followed by adsorption of monomethyl-and dimethylgallium at the surface, desorption of the remaining organic radicals, and then incorporation into the crystal.…”

Section: Proposed Chemistry For Mocvd Growthmentioning

confidence: 97%

Understanding MOCVD Gas Chemistry to Reduce the Cost of Ownership for GaN LED and AsP CPV Technologies

et al. 2012

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As compound semiconductors continue to make inroads into common electronic devices, it is critically important to lower the cost of the primary metal-organic chemical vapor deposition (MOCVD) epitaxial process, which creates the foundation for the devices. Both GaN-based light-emitting diode (LED) and AsP-based concentrator photovoltaic (CPV) markets have been focused on simultaneous cost-reduction, cycle time reductions, and device efficiency improvements, which can be realized utilizing higher growth rates and operating pressures. To achieve these goals, it has become increasingly important to understand the underlying growth mechanisms that drive the chemistry within the MOCVD process.Higher growth rates and higher operating pressures both result in parasitic gas-phase particle formation, which degrades the physical, electrical and optical properties of the deposited layers. In extreme cases, it can reduce the deposition efficiency to the point where increasing the reactant constituents results in reduced growth rates. In this paper, we will examine the tradeoffs that need to be made to achieve good crystal quality with abrupt interfaces, smooth surface morphology, and good minority carrier properties for films deposited at high growth rates and high pressure. While exceptional device performance has been achieved for both GaN-based LEDs and AsP-based CPV cells, it is primarily cost that is limiting full-scale adoption of compound semiconductors into these potentially enormous markets.

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Mechanism of carbon incorporation during GaAs epitaxy

Cited by 25 publications

References 0 publications

Growth behavior of GaSb by metal–organic vapor-phase epitaxy

Growth behavior of GaSb by metal–organic vapor-phase epitaxy

The GaAs(001)-(2 × 4) Surface: Structure, Chemistry, and Adsorbates

Understanding MOCVD Gas Chemistry to Reduce the Cost of Ownership for GaN LED and AsP CPV Technologies

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