Seeded growth of AlN on SiC substrates and defect characterization

Lü, Peng; Edgar, James H.; Cao, Chunshe; Hohn, Keith L.; Dalmau, Rafael; Schlesser, R.; Sitar, Zlatko

doi:10.1016/j.jcrysgro.2008.01.010

Cited by 47 publications

(47 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The symmetric (00.2) rocking curve measurements performed at different points over the surface of a 1-inch diameter template show no significant change in FWHM values and peak positions/intensities, indicating good structural homogeneity of the samples. The obtained FWHM values in this work are much lower than the already literature-reported values for AlN crystals grown on SiC substrates, 11,19,20 and are almost comparable with the homo-epitaxially grown crystals.…”

Section: Structural Qualitycontrasting

confidence: 45%

Bulk AlN single crystal growth on foreign substrate and preparation of free-standing native seeds

Sumathi

2013

CrystEngComm

View full text Add to dashboard Cite

Physical vapour transport growth of aluminium nitride (AlN) single crystals on silicon carbide (SiC) substrates has been optimised and crack-free, large-area, free-standing (0001) AlN wafers were prepared from the grown template crystals. 28 mm diameter single crystals without any polycrystalline surroundings were obtained. Different off-oriented substrates give rise to different growth modes. Sharp and symmetric line shapes of X-ray diffraction (XRD) rocking curves and high intense Raman phonon mode peaks prove high structural quality and homogeneity of the grown crystals. Full width at half maximum of the rocking curves is 72 arcsec for symmetric 00. demonstrates that AlN templates prepared on SiC as a foreign substrate can be used as native seeds for the growth of further homo-epitaxial layers and crystalline boules.

show abstract

Section: Structural Qualitycontrasting

confidence: 45%

Bulk AlN single crystal growth on foreign substrate and preparation of free-standing native seeds

Sumathi

2013

CrystEngComm

View full text Add to dashboard Cite

show abstract

“…Lu et al [27] grew AlN crystals on 3.5° off-oriented Si-polar (0001) 6H-SiC seeds in a container of hotpressed boron nitride (HPBN) with graphite heaters and insulation at source temperatures of 1830°C. Two samples fabricated had different colorations (bluish and amber), corresponding to different silicon (3 and 6 % at.)…”

Section: Introductionmentioning

confidence: 99%

Growth of AlN bulk crystals on SiC seeds: Chemical analysis and crystal properties

Bickermann

Filip²,

Epelbaum³

et al. 2012

Journal of Crystal Growth

View full text Add to dashboard Cite

Highlights:-Different growth conditions used to control SiC incorporation in AlN bulk growth -Phonon energies and band-gap of the crystals close to 'pure AlN' -Deep-UV opacity regardless of silicon and carbon content -Two types of samples with very different absorption and luminescence -No pseudo-binary alloy, but highly compensated, Si/C co-doped AlN Abstract AlN single crystals are grown by physical vapor transport (PVT) in sintered TaC crucibles in the presence of SiC, i.e. by seeding on 6H-SiC or by adding SiC to the AlN source material. Different growth conditions, i.e. growth temperatures T = 1900-2050°C and off-orientation angles in respect to [0001]  = 0-42°, are applied in order to investigate to which extent the incorporation of Si and/or C can be controlled during PVT growth. Chemical analysis is performed by energy-dispersive X-ray analysis (EDX), secondary ion mass spectrometry (SIMS), and Rutherford backscattering spectroscopy (RBS). The grown crystals are significantly contaminated with Si and C in the range of several atomic percents, but they do not represent pseudo-binary AlN-SiC solid solutions. Samples cut from these crystals are probed by Raman micro-spectroscopy, optical absorption, cathodoluminescence (CL), and near band-gap photoluminescence (PL) in order to evaluate the crystal properties. All crystals exhibit phonon bands at the positions of AlN phonon energies, and a low-temperature band-gap exceeding 5.8 eV, which is only slightly lower than the band-gap of pure AlN. On the other hand, the samples show very different optical properties below the band-gap, including coloration. As the changes in optical properties do not correlate to chemical analysis, we suggest that self-compensation of silicon 2 and carbon as well as formation of intrinsic defects lead to a complex compensation scenario in the samples. The grown crystals are thus to be considered as highly compensated, Si/C co-doped AlN.

show abstract

“…Studies of high-electron mobility transistors (HEMTs) with the ALGaN channel 7 grown on different substrates also demonstrate the superiority of the single crystal AlN substrates (Hu et al, 2003), in particularity, the use of AlN substrates improved the crystalline quality of the AlGaN layer and lowered the sheet resistance of the 2-dimensional electron gas (Hashimoto et al, 2010). The substrates cut from the bulk crystals along the specific crystallographic plane can have different orientation (polar, semipolar or nonpolar) (Lu et al, 2008) 8 , enhancing the freedom of the device design (Mymrin et al, 2005;Schowalter et al, 2006;Stutzmann et al, 2001): an engineer, using the spontaneous and piezoelectric polarization that is a nonlinear function of the strain and the composition of nitride materials, can tailor the surface and interface charges 7 The channel layer substitution of a wider bandgap AlGaN for a conventional GaN in high electron mobility transistors is an effective method of drastically enhancing the breakdown voltage (Nanjo et al, 2008). 8 For a long time attempts to grow the nitride epitaxial layers on the nonpolar planes were unsuccessful producing the low quality films (Karpov, 2009).…”

Section: Epitaxial Layers and Devices On Single-crystal Native Iii-nimentioning

confidence: 99%

“…Either a spontaneous nucleation (a self-seeding growth) without any attempt to control the crystal orientation or an intentional seeding (homoepitaxial (Hartmann et al, 2008) or heteroepitaxial (Lu, 2006;Miyanaga et al, 2006)) can be exploited. The SiC substrates are often used (Lu et al, 2008;Mokhov et al, 2002), other substrates -sapphire, tantalum carbide (TaC) and niobium carbide (NbC) -also have been tried (Lee, 2007). The decomposition of SiC at high temperature affects the growth morphology and could provoke the growth of polycrystalline AlN (Noveski et al, 2004a).…”

Section: Sublimation Growth Of Aln Crystalsmentioning

confidence: 99%