Preparation of a Freestanding AlN Substrate from a Thick AlN Layer Grown by Hydride Vapor Phase Epitaxy on a Bulk AlN Substrate Prepared by Physical Vapor Transport

Kumagai, Yoshinao; Kubota, Yuki; Nagashima, Toru; Kinoshita, Toru; Dalmau, Rafael; Schlesser, R.; Moody, Baxter; Xie, Jinqiao; Murakami, Hisashi; Koukitu, Akinori; Sitar, Zlatko

doi:10.1143/apex.5.055504

Cited by 128 publications

(111 citation statements)

References 13 publications

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“…It was also found that the Si and C impurity concentrations in the overgrown AlN layer reduced to half of those in the PVT-AlN substrates. In another study, [54] FWHM values as small as 31 and 32 arcsec have been reported for the (0002) and (101 1) reflections of ω-rocking curves, respectively, for 114 μm-thick HVPE-AlN, grown on a bulk PVT-AlN substrate. The HVPE-AlN has larger external optical transmittance in the DUV range compared to the PVT-AlN substrate, with a steep optical transmission cutoff at 206.5 nm (Figure 3), which was attributed to lower concentrations of carbon, and oxygen impurities, and VAl in the HVPE-AlN substrate.…”

Section: Growth and Optical Properties Of Bulk Aln For Duv Ledsmentioning

confidence: 93%

Status of Growth of Group III-Nitride Heterostructures for Deep Ultraviolet Light-Emitting Diodes

Ding¹,

Avrutin²,

Özgür³

et al. 2017

Preprint

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Abstract:We overview recent progress in growth aspects of group III-nitride heterostructures for deep ultraviolet (DUV) light-emitting diodes (LEDs), with particular emphasis on the growth approaches for attaining high-quality AlN and high Al-molar fraction AlGaN. The discussion commences with the introduction of the current status of group III-nitride DUV LEDs and the remaining challenges. This segues into discussion of LED designs enabling high device performance followed by the review of advances in the methods for the growth of bulk single crystal AlN intended as a native substrate together with a discussion of its UV transparency. It should be stated, however, that due to the high-cost of bulk AlN substrates at the time of this writing, the growth of DUV LEDs on foreign substrates such as sapphire still dominates the field. On the deposition front, the heteroepitaxial growth approaches incorporate high-temperature metal organic chemical vapor deposition (MOCVD) and pulsed-flow growth, a variant of MOCVD, with the overarching goal of enhancing adatom surface mobility, and thus epitaxial lateral overgrowth which culminates in minimization the effect of lattice-and thermal-mismatches. This is followed by addressing the benefits of pseudomorphic growth of strained high Al-molar fraction AlGaN on AlN. Finally, methods utilized to enhance both p-and n-type conductivity of high Al-molar fraction AlGaN are reviewed.

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Section: Growth and Optical Properties Of Bulk Aln For Duv Ledsmentioning

confidence: 93%

Status of Growth of Group III-Nitride Heterostructures for Deep Ultraviolet Light-Emitting Diodes

Ding¹,

Avrutin²,

Özgür³

et al. 2017

Preprint

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show abstract

“…Different methods have been used to grow AlN with a low dislocation density such as physical vapor transport (PVT) [8], solution growth [9], thermal nitridation [10], metalorganic chemical vapor deposition (MOCVD) [11] and hydride (or halogen) vapor phase epitaxy (HVPE) [12,13]. The most successful methods to provide substrates of high structural quality are the PVT method [8] or a combination of PVT and HVPE methods [14,15]. They provide AlN substrates with low dislocation densities (<10 4 cm −2 ) able to be used for AlGaN-based deep UV light-emitting devices.…”

Section: Introductionmentioning

confidence: 99%

“…All the experiments described in Table 1 led to epitaxial growth on (0001) sapphire. No disorientation is observed and AlN presents its classical orientation AlN (0001)//sapphire (0001) and AlN //sapphire [11][12][13][14][15][16][17][18][19][20]. Cracks could be observed on the surface of some samples (see Table 2 for details).…”

mentioning

confidence: 95%

Epitaxial Growth of AlN on (0001) Sapphire: Assessment of HVPE Process by a Design of Experiments Approach

et al. 2017

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Abstract:This study aims to present the interest of using a design of experiments (DOE) approach for assessing, understanding and improving the hydride vapor phase epitaxy (HVPE) process, a particular class of chemical vapor deposition (CVD) process. The case of the HVPE epitaxial growth of AlN on (0001) sapphire will illustrate this approach. The study proposes the assessment of the influence of 15 process parameters on the quality or desired properties of the grown layers measured by 9 responses. The general method used is a screening design with the Hadamard matrix of order 16. For the first time in the growth of AlN by CVD, a reliable estimation of errors is proposed on the measured responses. This study demonstrates that uncontrolled release of condensed species from the cold wall is the main drawback of this process, explaining many properties of the grown layers that could be mistakenly attributed to other phenomena without the use of a DOE. It appears also that the size of nucleation islands, and its corollary, the stress state of the layer at room temperature, are key points. They are strongly correlated to the crystal quality. Due to the intrinsic limitations of the screening design, the complete optimization of responses cannot be proposed but general guidelines for hydride (or halogen) vapor phase epitaxy (HVPE) experimentations, in particular with cold wall apparatus, are given.

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“…A number of groups fabricate bulk AlN single crystal using a sublimation method [1][2][3] and an alumina reduction method [4][5][6] . Recently, Kumagai et al 7) and Kangawa et al 8) grew AlN single crystal by the hydride vapor phase epitaxy method and Li 3 N solution growth method, respectively, using bulk AlN as a seed crystal fabricated by the sublimation method. Bockowski et al fabricated AlN crystals from Al melt at high temperature up to 2000 K and high N 2 pressure of order of 1 GPa without seed crystal 9) .…”

Section: Introductionmentioning

confidence: 99%

Effects of Growth Conditions on AlN Layer Grown by Ga-Al Liquid Phase Epitaxy

2017

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We developed an original liquid phase epitaxy technique that uses Ga-Al solution to grow AlN on surface nitrided sapphire substrates. In this paper, effects of temperature, solution composition, and N 2 gas ow rate on the growth of AlN layer were investigated. The AlN layer grown in the solution with higher Al content and higher growth temperature tended to dissolve into the solution, thus, the AlN layers exhibited inhomogeneous surface. The growth rate had a maximum at 60 mol%Al and at 1673 K for solution composition dependence and growth temperature dependence, respectively. On the other hand, the growth rate monotonically increased with increasing N 2 gas ow rate. Based on these results, growth mechanism and rate-determined step of this liquid phase epitaxy process were discussed.

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Preparation of a Freestanding AlN Substrate from a Thick AlN Layer Grown by Hydride Vapor Phase Epitaxy on a Bulk AlN Substrate Prepared by Physical Vapor Transport

Cited by 128 publications

References 13 publications

Status of Growth of Group III-Nitride Heterostructures for Deep Ultraviolet Light-Emitting Diodes

Status of Growth of Group III-Nitride Heterostructures for Deep Ultraviolet Light-Emitting Diodes

Epitaxial Growth of AlN on (0001) Sapphire: Assessment of HVPE Process by a Design of Experiments Approach

Effects of Growth Conditions on AlN Layer Grown by Ga-Al Liquid Phase Epitaxy

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