Study of Al diffusion in GaN during metal organic vapor phase epitaxy of AlGaN/GaN and AlN/GaN structures

Chaaben, N.; Laifi, J.; Bouazizi, H.; Saidi, C.; Bchetnia, A.; Jani, B. El

doi:10.1016/j.mssp.2015.11.008

Cited by 16 publications

(10 citation statements)

References 34 publications

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“…A possible interpretation is that Al diffusion into the h-BN layer causes the discontinuous h-BN layer as well as the w-AlN inclusions. Previous studies reported that high growth temperature of AlN (>1100 °C) causes Al diffusion into other materials such as GaN or GaAs. − In particular, Haneda et al have demonstrated that the diffusion coefficient of Al ( D Al ) is increased by 2 orders of magnitude when the growth temperature is increased by 100 °C . In our study, high-temperature AlN/h-BN structures, which were grown at 1280 °C (almost 200 °C higher than conventional AlN/BN structures), enable Al atoms to have more kinetic energy and diffuse into h-BN layers, increasing the Al concentration there.…”

Section: Resultsmentioning

confidence: 55%

Control of the Mechanical Adhesion of III–V Materials Grown on Layered h-BN

Vuong

Mballo

Patriarche

et al. 2020

ACS Appl. Mater. Interfaces

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Hexagonal boron nitride (h-BN) can be used as a p-doped material in wide-bandgap optoelectronic heterostructures or as a release layer to allow lift-off of grown three-dimensional (3D) GaN-based devices. To date, there have been no studies of factors that lead to or prevent lift-off and/or spontaneous delamination of layers. Here, we report a unique approach of controlling the adhesion of this layered material, which can result in both desired lift-off layered h-BN and mechanically inseparable robust h-BN layers. This is accomplished by controlling the diffusion of Al atoms into h-BN from AlN buffers grown on h-BN/sapphire. We present evidence of Al diffusion into h-BN for AlN buffers grown at high temperatures compared to conventional-temperature AlN buffers. Further evidence that the Al content in BN controls lift-off is provided by comparison of two alloys, Al 0.03 B 0.97 N/sapphire and Al 0.17 B 0.83 N/sapphire. Moreover, we tested that management of Al diffusion controls the mechanical adhesion of high-electron-mobility transistor (HEMT) devices grown on AlN/h-BN/sapphire. The results extend the control of two-dimensional (2D)/3D hetero-epitaxy and bring h-BN closer to industrial application in optoelectronics.

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Section: Resultsmentioning

confidence: 55%

Control of the Mechanical Adhesion of III–V Materials Grown on Layered h-BN

Vuong

Mballo

Patriarche

et al. 2020

ACS Appl. Mater. Interfaces

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“…The diffusion ability of Al atoms in solid crystalline layers seems to be higher than that of Ga. 53−55 In AlGaN and AlN HEMT manufacturing, it was observed that a high thermal budget provided after the GaN channel deposition, for example high-temperature barrier growth, surface passivation, and metal contact formation, is a source of increased alloy disorder scattering and degradation of the 2DEG mobility. 26,54,56 In Figure 9a we show our calculation of the conduction band edge and the electron charge distribution of the HEMT structure grown without an interlayer (sample A1) at 1000 °C with thickness and composition information obtained from SIMS and TEM analysis (Figure S1, Supporting Information). The 6.2 nm thick AlGaN grading caused by diffusion of Al into the GaN channel causes the 2DEG to spread across the interlayer.…”

Section: ■ Discussionmentioning

confidence: 99%

Effect of AlN and AlGaN Interlayers on AlScN/GaN Heterostructures Grown by Metal–Organic Chemical Vapor Deposition

Streicher

Manz

Kirste

et al. 2023

Crystal Growth & Design

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AlScN/GaN heterostructures with their high sheet carrier density (n s ) in the two-dimensional electron gas (2DEG) have a high potential for high-frequency and high-power electronics. The abruptness of the heterointerface plays a key role in the 2DEG confinement, and the presence of interlayers (AlN, AlGaN) affects n s and electron mobility (μ) and determines the sheet resistance (R sh ). AlScN/GaN heterostructures suitable for high-electron mobility transistors (HEMT) with and without a nominal AlN interlayer were grown by metal−organic chemical vapor deposition (MOCVD) and characterized electrically and structurally to gain a systematic insight into the unintentional formation and control of graded AlGaN interlayers by diffusion of atoms at the heterointerface. The AlN interlayer increases n s from 2.52 × 10 13 cm −2 to 3.25 × 10 13 cm −2 and, as calculated by one-dimensional Schrodinger−Poisson simulations, improves the 2DEG confinement. The barrier growth temperature was varied from 900 °C to 1200 °C to investigate the effect of the thermal budget on diffusion. Growth at 900 °C reduces the thickness of the graded AlGaN interlayer and improves the 2DEG confinement, leading to R sh of 211 Ω/sq, n s of 2.98 × 10 13 cm −2 , and μ of 998 cm 2 /(Vs).

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“…In Al0.03Ga0.97N/AlN superlattices (SLs) a D value of 7⨯10 -20 cm 2 /s has been reported at 1000 °C [8] and a D value of 1.3⨯10 -17 cm 2 /s has been extracted from experiments in Al0.06Ga0.94N/GaN quantum well structures annealed at 1500 °C [9]. While a D value as high as 10 -14 cm 2 /s has been determined for Al0.02Ga0.98N/GaN and AlN/GaN structures annealed at 1100 °C [7].…”

Section: Introductionmentioning

confidence: 99%

“…Chemical diffusion is another well-known phenomenon that can lead to an interface layer. So far few studies have dealt with cation interdiffusion in the GaN/AlN system: during MOCVD growth at 1100 °C [7] and after annealing at temperatures going from 1000 °C to 1700 °C [8][9][10]. Based on these studies a set of diffusion coefficients were reported in the literature, but the estimated values spread over a wide range and are not consistent with each other, even if their temperature dependence is taken into account.…”

Section: Introductionmentioning

confidence: 99%