Comparative Study of Boron Precursors for Chemical Vapor‐Phase Deposition‐Grown Hexagonal Boron Nitride Thin Films

Yamada, Hisashi; Inotsume, Sho; Kumagai, Naoto; Yamada, Toshikazu; Shimizu, Mitsuaki

doi:10.1002/pssa.202000241

Cited by 13 publications

(23 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The growth of thin sp 2 -BN films on Al 2 O 3 substrate was initially reported by Nakamura in 1986, which suggested that to deposit sp 2 -BN with a c -axis lattice constant similar to that of bulk hBN, a growth temperature of 1500 °C was necessary . It was experimentally validated by Kobayashi et al in 2008, followed by others, that growth temperatures greater than 1200 °C are sufficient to obtain hBN which otherwise leads to a turbostratic form of BN at lower temperatures. − The typical precursors used for hBN growth on non-metallic substrates include triethyl boron [B(C 2 H 5 ) 3 , TEB], trimethyl boron [B(CH 3 ) 3 , TMB] for B and ammonia (NH 3 ) as the source of N. It is well known, however, that organic sources such as TEB can result in carbon incorporation in the film which is a concern for the growth of high purity hBN films , Moreover, for applications such as quantum computing and sensing that utilize SPE centers in hBN, excessive carbon contamination in the film could be an issue due to high autofluorescence, thus making it challenging to isolate individual structural defects in hBN, limiting the use of hBN for such applications. , Therefore, using carbon free hydride precursors such as diborane (B 2 H 6 ) and NH 3 for B and N respectively, one can potentially eliminate the issue with C contamination in the films.…”

Section: Introductionmentioning

confidence: 99%

Substrate Modification during Chemical Vapor Deposition of hBN on Sapphire

Bansal

Hilse

Huet

et al. 2021

ACS Appl. Mater. Interfaces

View full text Add to dashboard Cite

A comparison of hexagonal boron nitride (hBN) layers grown by chemical vapor deposition on C-plane (0001) versus A-plane (112̅ 0) sapphire (α-Al 2 O 3 ) substrate is reported. The high deposition temperature (>1200 °C) and hydrogen ambient used for hBN deposition on sapphire substantially alters the C-plane sapphire surface chemistry and leaves the top layer(s) oxygen deficient. The resulting surface morphology due to H 2 etching of C-plane sapphire is inhomogeneous with increased surface roughness which causes non-uniform residual stress in the deposited hBN film. In contrast to C-plane, the A-plane of sapphire does not alter substantially under a similar high temperature H 2 environment, thus providing a more stable alternative substrate for high quality hBN growth. The E 2g Raman mode full width at half-maximum (FWHM) for hBN deposited on C-plane sapphire is 24.5 ± 2.1 cm −1 while for hBN on A-plane sapphire is 24.5 ± 0.7 cm −1 . The lesser FWHM standard deviation on A-plane sapphire indicates uniform stress distribution across the film due to reduced undulations on the surface. The photoluminescence spectra of the hBN films at 300 and 3 K, obtained on C-plane and A-plane sapphire exhibit similar characteristics with peaks at 4.1 and 5.3 eV reported to be signature peaks associated with defects for hBN films deposited under lower V/III ratios. The dielectric breakdown field of hBN deposited on A-plane sapphire was measured to be 5 MV cm −1 , agreeing well with reports on mechanically exfoliated hBN flakes. Thus, under the typical growth conditions required for high crystalline quality hBN growth, A-plane sapphire provides a more chemically stable substrate.

show abstract

Section: Introductionmentioning

confidence: 99%

Substrate Modification during Chemical Vapor Deposition of hBN on Sapphire

Bansal

Hilse

Huet

et al. 2021

ACS Appl. Mater. Interfaces

View full text Add to dashboard Cite

show abstract

“…In this section, we discuss the formation of BNNS with HBNH and BN precursors. These precursors can potentially be used in gas-phase synthesis methods. − ,, Additionally, HBNH is an important product of the B 2 H 6 /NH 3 configuration, which is used for the CVD synthesis of 2D-hBN.…”

Section: Resultsmentioning

confidence: 99%

“…3 While the C-based precursors do not have this issue, they could lead to carbon contamination in 2D-hBN. 4 The CVD growth of hBN is affected by the type of precursor, ambient gas conditions (temperature, pressure), and the substrate. These variables affect the quality as well as the growth rate of 2D-hBN.…”

Section: Introductionmentioning

confidence: 99%

“…The precursors containing just B, N, and H atoms are attractive because they do not produce highly toxic byproducts such as BF 3 or BCl 3 . While the C-based precursors do not have this issue, they could lead to carbon contamination in 2D-hBN . The CVD growth of hBN is affected by the type of precursor, ambient gas conditions (temperature, pressure), and the substrate.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

ReaxFF Force Field Development for Gas-Phase hBN Nanostructure Synthesis

2022

View full text Add to dashboard Cite

Two-dimensional (2D) hexagonal boron nitride materials are isomorphs of carbon nanomaterials and hold promise for electronics applications owing to their unique properties. Despite the recent advances in synthesis, the current production capacity for boron nitride (BN) nanostructures is far behind that for carbon-based nanostructures. Understanding the growth mechanism of BN nanostructures through modeling and experiments is key to improving this situation. In the current work, we present the development of a ReaxFF-based force field capable of modeling the gas-phase chemistry important for the chemical vapor deposition (CVD) synthesis process. This force field is parameterized to model the boron nitride nanostructure (BNNS) formation in the gas phase using BN and HBNH as precursors. Our ReaxFF simulations show that BN is the best of these two precursors in terms of quality and the size of BNNSs. The BN precursors lead to the formation of closed BNNSs. However, BNNSs are replaced with complex polymeric structures at temperatures of 2500 K and higher due to entropic effects. Compared to the BN precursors, the HBNH precursors form relatively small, flat, and low-quality BNNSs, but this structure is less affected by temperature. Additives like H2 significantly affect the BNNS formation by preventing closed BNNS formation. Our results show the ReaxFF capability in predicting the BN gas-phase chemistry and BNNS formation, thus providing key insights for experimental synthesis.

show abstract

“…Among various 2D materials, hexagonal boron nitride (h‐BN) is expected for deep ultraviolet light‐emitting devices [ 1,2 ] and gate dielectric layer for graphene transistors. [ 3 ] There are various growth methods for growing BN films, such as high‐temperature and high‐pressure (HTHP) method, [ 2 ] thermal chemical vapor deposition (CVD), [ 4–26 ] plasma‐assisted CVD, [ 27–31 ] and molecular beam epitaxy (MBE). [ 32 ] Among them, CVD growth is suitable for heteroepitaxy devices in terms of mass production.…”

Section: Introductionmentioning

confidence: 99%

Reduction in Residual Impurities in Chemical Vapor Deposition–Grown Hexagonal Boron Nitride Thin Films

Yamada

2023

Physica Status Solidi (b)

Self Cite

View full text Add to dashboard Cite

The residual impurities in chemical vapor deposition (CVD)‐grown hexagonal boron nitride (h‐BN) on Al2O3 substrate grown by CVD using BN‐molded susceptor with B2H6 as a boron precursor are investigated. The Si, C, and O residual impurities of 2.6 × 1016, 3.4 × 1018, and 2.0 × 1017 cm−3 are achieved. These concentrations are two orders of magnitude lower than those when grown on the SiC‐coated graphite susceptor using trimethylboron (TMB) and the lowest values in the CVD‐grown h‐BN thin films. The cathodoluminescence spectrum has 5.5 eV as a broad peak and 4 eV as several peaks. The free excitonic recombination at the higher energy emission (5.79 eV) is owing to the reduction in residual impurities. The absorption coefficient of 1 × 104 cm−1 is observed in the energy range below 5 eV only when using the SiC‐coated graphite susceptor, which is most probably associated with Si contamination in the BN layer. The negligible absorption coefficient when using the BN‐molded susceptor presents high‐purity h‐BN signature.

show abstract

Comparative Study of Boron Precursors for Chemical Vapor‐Phase Deposition‐Grown Hexagonal Boron Nitride Thin Films

Cited by 13 publications

References 42 publications

Substrate Modification during Chemical Vapor Deposition of hBN on Sapphire

Substrate Modification during Chemical Vapor Deposition of hBN on Sapphire

ReaxFF Force Field Development for Gas-Phase hBN Nanostructure Synthesis

Reduction in Residual Impurities in Chemical Vapor Deposition–Grown Hexagonal Boron Nitride Thin Films

Contact Info

Product

Resources

About