MOCVD growth of 2D WS2 on SiO2: nucleation mechanism and kinetics

Caymax, Mathy; Kazzi, Salim El; Huyghebaert, Cedric

doi:10.7567/ssdm.2019.d-1-03

Cited by 4 publications

(3 citation statements)

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“…However, the use of the metal–organic precursor Mo(CO) 6 above its decomposition temperature implies that the metal precursor adsorption is almost irreversible. Hence, surface diffusion is a dominant diffusion pathway for Mo ad-species . On the other hand, due to the comparatively higher vapor pressure of S species, S species can desorb and further pursue gas-phase diffusion, leading to a shorter lifetime on the surface and reversible adsorption (Figure C-I).…”

Section: Results and Discussionmentioning

confidence: 99%

“…Hence, surface diffusion is a dominant diffusion pathway for Mo adspecies. 48 On the other hand, due to the comparatively higher vapor pressure of S species, S species can desorb and further pursue gas-phase diffusion, leading to a shorter lifetime on the surface and reversible adsorption (Figure 2C-I). As a consequence of this distinct difference in diffusional transport and Ehrlich−Schwoebel barrier depending on the type of Mo and S ad-species, the concentration and spatial distribution of those adatoms can differ near the step edges.…”

Section: Acs Nanomentioning

confidence: 99%

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Chemical Vapor Deposition of a Single-Crystalline MoS₂ Monolayer through Anisotropic 2D Crystal Growth on Stepped Sapphire Surface

Kandybka,

Groven,

Medina Silva

et al. 2024

ACS Nano

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Recently, a step-flow growth mode has been proposed to break the inherent molybdenum disulfide (MoS 2 ) crystal domain bimodality and yield a single-crystalline MoS 2 monolayer on commonly employed sapphire substrates. This work reveals an alternative growth mechanism during the metal−organic chemical vapor deposition (MOCVD) of a single-crystalline MoS 2 monolayer through anisotropic 2D crystal growth. During early growth stages, the epitaxial symmetry and commensurability of sapphire terraces rather than the sapphire step inclination ultimately govern the MoS 2 crystal orientation. Strikingly, as the MoS 2 crystals continue to grow laterally, the sapphire steps transform the MoS 2 crystal geometry into diamond-shaped domains presumably by anisotropic diffusion of ad-species and facet development. Even though these MoS 2 domains nucleate on sapphire with predominantly bimodal 0 and 60°azimuthal rotation, the individual domains reach lateral dimensions of up to 200 nm before merging seamlessly into a single-crystalline MoS 2 monolayer upon coalescence. Plan-view transmission electron microscopy reveals the single-crystalline nature across 50 μm by 50 μm inspection areas. As a result, the median carrier mobility of MoS 2 monolayers peaks at 25 cm 2 V −1 s −1 with the highest value reaching 28 cm 2 V −1 s −1 . This work details synthesis−structure correlations and the possibilities to tune the structure and material properties through substrate topography toward various applications in nanoelectronics, catalysis, and nanotechnology. Moreover, shape modulation through anisotropic growth phenomena on stepped surfaces can provide opportunities for nanopatterning for a wide range of materials.

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Section: Results and Discussionmentioning

confidence: 99%

Section: Acs Nanomentioning

confidence: 99%

Chemical Vapor Deposition of a Single-Crystalline MoS₂ Monolayer through Anisotropic 2D Crystal Growth on Stepped Sapphire Surface

Kandybka,

Groven,

Medina Silva

et al. 2024

ACS Nano

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“…21) CVD is the most promising technique to develop the aforementioned structures. In WS 2 CVD reported thus far, [22][23][24][25][26][27] WF 6 and W(CO) 6 have been widely used as W precursors and H 2 S as a S precursor. However, WF 6 is toxic, and W(CO) 6 is a sublimable solid, so stable transport is a concern.…”

Section: Introductionmentioning

confidence: 99%

Conformal deposition of WS₂ layered film by low-temperature metal-organic chemical vapor deposition

Cho

Sawamoto

Machida³

et al. 2023

Jpn. J. Appl. Phys.

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WS2 metal-organic (MO) chemical vapor deposition was demonstrated on Si and Al2O3 substrates. Novel MO W precursor of n-BuNC-W(CO)5 and (t-C4H9)2S2. as S precursor were synthesized for the purpose. The obtained films were layered 1T structure as a typical transition metal di-chalcogenide with almost the stoichiometric compositions. The film was significantly stable for 60 days shelf time in the air atmosphere. The layered structure can cover conformally on the 3-simensional fin structure with the layers parallel to the fin surface everywhere.

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Challenges of Wafer‐Scale Integration of 2D Semiconductors for High‐Performance Transistor Circuits

et al. 2022

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Large‐area 2D‐material‐based devices may find applications as sensor or photonics devices or can be incorporated in the back end of line (BEOL) to provide additional functionality. The introduction of highly scaled 2D‐based circuits for high‐performance logic applications in production is projected to be implemented after the Si‐sheet‐based CFET devices. Here, a view on the requirements needed for full wafer integration of aggressively scaled 2D‐based logic circuits, the status of developments, and the definition of the gaps to be bridged is provided. Today, typical test vehicles for 2D devices are single‐sheet devices fully integrated in a lab environment, but transfer to a more scaled device in a fab environment has been demonstrated. This work reviews the status of the module development, including considerations for setting up fab‐compatible process routes for single‐sheet devices. While further development on key modules is still required, substantial progress is made for MX2 channel growth, high‐k dielectric deposition, and contact engineering. Finally, the process requirements for building ultra‐scaled stacked nanosheets are also reflected on.

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MOCVD growth of 2D WS2 on SiO2: nucleation mechanism and kinetics

Cited by 4 publications

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Chemical Vapor Deposition of a Single-Crystalline MoS₂ Monolayer through Anisotropic 2D Crystal Growth on Stepped Sapphire Surface

Chemical Vapor Deposition of a Single-Crystalline MoS₂ Monolayer through Anisotropic 2D Crystal Growth on Stepped Sapphire Surface

Conformal deposition of WS₂ layered film by low-temperature metal-organic chemical vapor deposition

Challenges of Wafer‐Scale Integration of 2D Semiconductors for High‐Performance Transistor Circuits

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MOCVD growth of 2D WS2 on SiO2: nucleation mechanism and kinetics

Cited by 4 publications

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Chemical Vapor Deposition of a Single-Crystalline MoS2 Monolayer through Anisotropic 2D Crystal Growth on Stepped Sapphire Surface

Chemical Vapor Deposition of a Single-Crystalline MoS2 Monolayer through Anisotropic 2D Crystal Growth on Stepped Sapphire Surface

Conformal deposition of WS2 layered film by low-temperature metal-organic chemical vapor deposition

Challenges of Wafer‐Scale Integration of 2D Semiconductors for High‐Performance Transistor Circuits

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Chemical Vapor Deposition of a Single-Crystalline MoS₂ Monolayer through Anisotropic 2D Crystal Growth on Stepped Sapphire Surface

Chemical Vapor Deposition of a Single-Crystalline MoS₂ Monolayer through Anisotropic 2D Crystal Growth on Stepped Sapphire Surface

Conformal deposition of WS₂ layered film by low-temperature metal-organic chemical vapor deposition