226–273 nm AlGaN deep‐ultraviolet light‐emitting diodes fabricated on multilayer AlN buffers on sapphire

Hasegawa, Hideki; Yatabe, Tohru; Noguchi, Norimichi; Ohashi, Tomoaki; Kamata, Norihiko

doi:10.1002/pssc.200779303

Cited by 29 publications

(17 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…employing the process of embedding an AlN nucleation layer, using NH 3 pulsed-flow AlN growth and then by alternately stacking the NH 3 pulsed-flow AlN and the continuous flow AlN growth layers. The minimum value of the edge-type dislocation density obtained by the ML-AlN grown on sapphire was 7×10 8 cm -2 [4]. We have achieved AlGaNand InAlGaN-based DUV-LEDs, with emission wavelengths in the range of 222-282 nm, by fabricating them on the ML-AlN templates [3][4][5].…”

mentioning

confidence: 97%

Fabrication of a low threading dislocation density ELO‐AlN template for application to deep‐UV LEDs

Hasegawa

Fujikawa

Norimatsu

et al. 2009

Phys. Status Solidi (c)

Self Cite

View full text Add to dashboard Cite

We have fabricated low threading dislocation density (TDD) AlN templates on sapphire substrates for application to deep‐ultraviolet (DUV) light‐emitting diodes (LEDs) by employing an epitaxial lateral overgrowth (ELO) process. An AlN stripe structure with a width of 5 μm and a spacing of 3 μm was formed by using inductive coupled plasma (ICP) etching. The AlN stripes were completely coalesced and embedded to create a flat surface after the growth of an approximately 15 μm‐thick ELO‐AlN layer, grown by low‐pressure metal‐organic chemical vapor deposition (LP‐MOCVD). We systematically investigated the appropriate V/III ratio and growth temperature for the ELO‐AlN. The edge‐type TDD of the AlN was reduced from 2×109 cm–2 (AlN stripe region) to 3×108 cm–2 (in the wing region of the ELO‐AlN), as estimated by cross‐sectional transmission electron microscope (TEM) imaging. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

show abstract

mentioning

confidence: 97%

Fabrication of a low threading dislocation density ELO‐AlN template for application to deep‐UV LEDs

Hasegawa

Fujikawa

Norimatsu

et al. 2009

Phys. Status Solidi (c)

Self Cite

View full text Add to dashboard Cite

show abstract

“…water disinfection, air purification, and ultra-high density optical recording [1]. Corresponding device structures feature AlGaN and AlInGaN epilayers with high aluminum contents [2]. In such cases, single-crystalline aluminum nitride (AlN) is the most promising substrate material.…”

mentioning

confidence: 99%

UV transparent single‐crystalline bulk AlN substrates

Bickermann

Epelbaum

Filip

et al. 2010

Phys. Status Solidi (c)

View full text Add to dashboard Cite

Bulk aluminum nitride (AlN) is a very promising substrate material for UV optoelectronics, and its UV transparency is of high interest for UV devices designed to emit through the substrate. We report on 500 μm thick bulk AlN substrates with plain UV transmittance exceeding 50% (i.e., absorption coefficients below 14 cm–1) for wavelengths from 220 nm to 380 nm in the main wafer area. Comparing the spectra of different AlN bulk samples, four major below band‐gap absorption bands are identified and interpreted based on a point defect model for AlN crystals. We conclude that a further reduction of oxygen contamination of the source material led to a significant decrease of UV absorption in both colorless and yellowish areas of those substrates. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

show abstract

“…The edge and screw-type dislocation densities in AlGaN buffer layers on AlN grown by the NH3 pulsed-flow multilayer growth technique were reported to be 7.5×10 8 and 3.8×10 7 cm -2 , respectively. [66] Different from the NH3 pulse-flow growth, both group III and group V precursors are sequentially modulated in the PALE method, wherein the NH3 pulse always follows the metalorganic pulses. Reduced parasitic pre-reactions and enhanced surface migration of Al adatoms, afforded by the PALE technique, promote lateral growth of AlN.…”

Section: Pulsed-flow Growth Of Aln and High Al-molar Fraction Alganmentioning

confidence: 99%

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

Ding¹,

Avrutin²,

Özgür³

et al. 2017

Preprint

View full text Add to dashboard Cite

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.

show abstract

226–273 nm AlGaN deep‐ultraviolet light‐emitting diodes fabricated on multilayer AlN buffers on sapphire

Cited by 29 publications

References 15 publications

Fabrication of a low threading dislocation density ELO‐AlN template for application to deep‐UV LEDs

Fabrication of a low threading dislocation density ELO‐AlN template for application to deep‐UV LEDs

UV transparent single‐crystalline bulk AlN substrates

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

Contact Info

Product

Resources

About