AlN grown on Si(1 1 1) by ammonia-molecular beam epitaxy in the 900–1200 °C temperature range

Tamariz, Sebastian; Martin, D.; Grandjean, N.

doi:10.1016/j.jcrysgro.2017.08.006

Cited by 44 publications

(14 citation statements)

References 39 publications

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“…By using the given process parameters, the growth of highly c -axis oriented AlN directly on smooth surfaces (RMS < 2 nm) of amorphous SiO 2 , (100) Si and poly-Si wafers can be achieved, despite the different crystallographic texture of the substrate materials, in agreement with several studies [ 29 , 33 , 34 , 41 ]. However, a smooth surface alone is not sufficient to grow high quality AlScN films on these substrates as the misaligned grains and high FWHM values are measured.…”

Section: Resultssupporting

confidence: 86%

Growth of Highly c-Axis Oriented AlScN Films on Commercial Substrates

Fichtner

Ghori

et al. 2022

Micromachines

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In this work, we present a method for growing highly c-axis oriented aluminum scandium nitride (AlScN) thin films on (100) silicon (Si), silicon dioxide (SiO2) and epitaxial polysilicon (poly-Si) substrates using a substrate independent approach. The presented method offers great advantages in applications such as piezoelectric thin-film-based surface acoustic wave devices where a metallic seed layer cannot be used. The approach relies on a thin AlN layer to establish a wurtzite nucleation layer for the growth of w-AlScN films. Both AlScN thin film and seed layer AlN are prepared by DC reactive magnetron sputtering process where a Sc concentration of 27% is used throughout this study. The crystal quality of (0002) orientation of Al0.73Sc0.27N films on all three substrates is significantly improved by introducing a 20 nm AlN seed layer. Although AlN has a smaller capacitance than AlScN, limiting the charge stored on the electrode plates, the combined piezoelectric coefficient d33,f with 500 nm AlScN is only slightly reduced by about 4.5% in the presence of the seed layer.

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Section: Resultssupporting

confidence: 86%

Growth of Highly c-Axis Oriented AlScN Films on Commercial Substrates

Fichtner

Ghori

et al. 2022

Micromachines

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“…Note that epitaxial strain engineering is a well-established technique for enhancing CMOS performance, engineering the electronic band structure, searching for better catalysts, and improving ferroelectric, ferromagnetic, and superconducting transition temperatures. ,− Nowadays, about ±3% epitaxial strains are common for oxide thin films; for example, a strain as large as −6% has been demonstrated in BiFeO 3 thin films. ,, Similarly, epitaxially grown nitrides are also quite common. − For example, AlN and GaN have been grown on the Si(111) surface with a large lattice mismatch. ,, The atomic ratio and substrate temperature during the growth play a very important role for minimizing defects and surface roughness. There is also a correlation between epitaxial strain evolution and surface crack formation . Promisingly, using the Al buffer layer, 300 nm-thick high crystalline AlN epitaxial films with a smooth surface have been grown on the Si substrate .…”

Section: Resultsmentioning

confidence: 99%

“…In this regard, epitaxially grown nitrides are also quite common. For example, AlN and GaN have been grown on the Si(111) surface with large lattice mismatch 74,75 . Interestingly, strain has been even proposed to stabilize the structures for highly doped nitrides 25…”

mentioning

confidence: 99%

Ferroelectricity and Large Piezoelectric Response of AlN/ScN Superlattice

Noor‐A‐Alam

Olszewski

Nolan

2019

ACS Appl. Mater. Interfaces

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Based on density functional theory, we investigate the ferroelectric and piezoelectric properties of the AlN/ScN superlattice, consists of ScN and AlN buckled monolayers alternating along crystallographic c-direction. We nd that the polar wurtzite (w-ScAlN) structure is mechanically and dynamically stable, and is more stable than the nonpolar hexagonal at conguration. We show that ferroelectric polarization switching can be possible for epitaxially tensile strained superlattice. Due to the elastic constant C 33 softening along with an increase in e 33 , the piezoelectric coecient d 33 of the superlattice is doubled compared to pure w-AlN. The combined enhancement of Born eective charges (Z 33) and the sensitivity of the atomic coordinates to external strain (∂u 3 ∂η 3) is the origin of large piezoelectric constant e 33. Moreover, we show that epitaxial biaxial tensile strain signicantly enhances the piezo-response, so that d 33 becomes seven times larger than that of w-AlN at 4% strain. The tensile strain results in a huge enhancement in e 33 by increasing Z 33 and ∂u 3 ∂η 3 , which boosts the piezoelectric coecient. As short-period superlattice growth and epitaxial strain are already experimentally demonstrated in wurtzite nitrides, our results show a new more controlled approach

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“…Further details on the growth of the AlN layer and the QDs can be found in Refs. [59,60]. The top QD plane was used for atomic force microscopy (AFM) and subsequently evaporated in the MBE reactor under vacuum at a temperature of 800 • C. Mesa structures and position markers were then fabricated by e-beam lithography.…”

Section: Methodsmentioning

confidence: 99%

Toward Bright and Pure Single Photon Emitters at 300 K Based on GaN Quantum Dots on Silicon

et al. 2020

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Quantum dots (QDs) based on III-nitride semiconductors are promising for single photon emission at non-cryogenic temperatures due to their large exciton binding energies. Here, we demonstrate GaN QD single photon emitters operating at 300 K with g (2) (0) = 0.17±0.08 under continuous wave excitation. At this temperature, single photon emission rates up to 6 × 10 6 s −1 are reached while g (2) (0) ≤ 0.5 is maintained. Our results are achieved for GaN QDs embedded in a planar AlN layer grown on silicon, representing a promising pathway for future interlinkage with optical waveguides and cavities. These samples allow exploring the limiting factors to key performance metrics for single photon sources, such as brightness and single photon purity. While high brightness is assured by large exciton binding energies, the single photon purity is mainly affected by the spectral overlap with the biexcitonic emission. Thus, the performance of a GaN QD as a single photon emitter depends on the balance between the emission linewidth and the biexciton binding energy. We identify small GaN QDs with an emission energy in excess of 4.2 eV as promising candidates for future room temperature applications, since the biexciton binding energy becomes comparable to the average emission linewidth of around 55 meV.Quantum dots (QDs) based on III-V semiconductors have attracted a lot of attention for their use as nonclassical light sources, with the single photon source being the simplest and most elemental representative. Such a source of single photons should be as bright as possible, while retaining a high single photon purity [1, 2]. However, key metrics for such QD-based single photon sources are usually achieved at cryogenic temperatures with the seminal In(Ga)As/(Al)GaAs system [3][4][5]. Identifying a material platform that can enable sufficiently performant single photon sources up to room temperature remains a challenging quest. In this respect, the main contenders are point defects in wide-bandgap semiconductors (2D materials [6] and bulk semiconductors [7, 8]), nitrogen and silicon vacancies in diamond [9], as well as semiconductor QDs [10][11][12]. It would be advantageous to employ a material system with high integrability into a suitable photonic environment that offers epitaxial control. In this regard, III-nitrides offer a unique possibility as bipolar doping can be achieved, foreign and homoepitaxial substrates are available, and growth and processing techniques are well established, leading to their widespread implementation at an industrial scale for solid state lighting.III-nitrides have shown promising advances in terms of single photon emission (SPE) by employing GaN/AlN [13,14], GaN/AlGaN [15,16] and InGaN/GaN QDs [17][18][19][20][21]. Furthermore, SPE at temperatures as high as 350 K [22] and two-photon emission up to 50 K [23] have been demonstrated. The progress towards room temperature operation is directly linked to the exciton-phonon coupling. With rising temperature the phonon bath becomes * sebastian.tamariz...

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AlN grown on Si(1 1 1) by ammonia-molecular beam epitaxy in the 900–1200 °C temperature range

Cited by 44 publications

References 39 publications

Growth of Highly c-Axis Oriented AlScN Films on Commercial Substrates

Growth of Highly c-Axis Oriented AlScN Films on Commercial Substrates

Ferroelectricity and Large Piezoelectric Response of AlN/ScN Superlattice

Toward Bright and Pure Single Photon Emitters at 300 K Based on GaN Quantum Dots on Silicon

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