Electrical and luminescent properties and deep traps spectra of N-polar GaN films

Polyakov, A. Y.; Smirnov, N. B.; Говорков, А. В.; Sun, Qian; Zhang, Y.; Cho, Y.S.; Lee, I.-H.; Han, Jung

doi:10.1016/j.mseb.2009.10.011

Cited by 10 publications

(10 citation statements)

References 35 publications

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“…The spectra show the band-to-band emission peak ~358 nm (3.464 eV), donor-acceptor-pair (DAP) band and LO phonon replica ~370–410 nm, and a weaker yellow luminescence for the three samples [11]. For a thicker LT buffer, the PL intensity is weaker.…”

Section: Resultsmentioning

confidence: 99%

“…The properties of Ga - and N -polar GaN are different in the direction of the polarization field, the incorporation of residual impurities, and the surface morphology [8–11]. Because of the low-quality epitaxial layers of N -polar GaN, the device performance of the N -polar LED is poor compared to that of the Ga -polar LED [4].…”

Section: Introductionmentioning

confidence: 99%

“…Because of the low-quality epitaxial layers of N -polar GaN, the device performance of the N -polar LED is poor compared to that of the Ga -polar LED [4]. The incorporation of oxygen in N -polar GaN during nitridation is much larger than that in Ga -polar GaN [10, 11]. Oxygen incorporates on nitrogen sites by bonding with neighboring Ga atoms and substitutes for nitrogen atoms on the N -polar GaN surface [10].…”

Section: Introductionmentioning

confidence: 99%

“…Oxygen incorporates on nitrogen sites by bonding with neighboring Ga atoms and substitutes for nitrogen atoms on the N -polar GaN surface [10]. By calculating the adsorption energy of oxygen on the different surfaces, atoms impinging on a group V site form three bonds to the Ga surface atoms, leading to a stronger bonding of oxygen atoms to the N -polar surface [11, 12]. …”

Section: Introductionmentioning

confidence: 99%

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Effects of Thickness of a Low-Temperature Buffer and Impurity Incorporation on the Characteristics of Nitrogen-polar GaN

et al. 2016

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In this study, effects of the thickness of a low temperature (LT) buffer and impurity incorporation on the characteristics of Nitrogen (N)-polar GaN are investigated. By using either a nitridation or thermal annealing step before the deposition of a LT buffer, three N-polar GaN samples with different thicknesses of LT buffer and different impurity incorporations are prepared. It is found that the sample with the thinnest LT buffer and a nitridation step proves to be the best in terms of a fewer impurity incorporations, strong PL intensity, fast mobility, small biaxial strain, and smooth surface. As the temperature increases at ~10 K, the apparent donor-acceptor-pair band is responsible for the decreasing integral intensity of the band-to-band emission peak. In addition, the thermal annealing of the sapphire substrates may cause more impurity incorporation around the HT-GaN/LT-GaN/sapphire interfacial regions, which in turn may result in a lower carrier mobility, larger biaxial strain, larger bandgap shift, and stronger yellow luminescence. By using a nitridation step, both a thinner LT buffer and less impurity incorporation are beneficial to obtaining a high quality N-polar GaN.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Effects of Thickness of a Low-Temperature Buffer and Impurity Incorporation on the Characteristics of Nitrogen-polar GaN

et al. 2016

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“…Traditionally, investigation of III-nitride materials and devices have used the Ga-polar orientation (0001). High quality material in this orientation completely suppressed across the surface and there are small-scale surface features present [20].…”

Section: Introductionmentioning

confidence: 92%

MOCVD growth of N-polar GaN on on-axis sapphire substrate: Impact of AlN nucleation layer on GaN surface hillock density

Marini

Leathersich

Mahaboob

et al. 2016

Journal of Crystal Growth

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We report on the impact of growth conditions on surface hillock density of N-polar GaN grown on nominally on-axis (0001) sapphire substrate by metal organic chemical vapor deposition (MOCVD). Large reduction in hillock density was achieved by implementation of an optimized high temperature AlN nucleation layer and use of indium surfactant in GaN overgrowth. A reduction by more than a factor of five in hillock density from 1000 to 170 hillocks/cm −2 was achieved as a result. Crystal quality and surface morphology of the resultant GaN films were characterized by high resolution x-ray diffraction and atomic force microscopy and found to be relatively unaffected by the buffer conditions. It is also shown that the density of smaller surface features is unaffected by AlN buffer conditions.

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N-polar III-nitride transistors

Wong

Mishra

2019

Semiconductors and Semimetals

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Electrical and luminescent properties and deep traps spectra of N-polar GaN films

Cited by 10 publications

References 35 publications

Effects of Thickness of a Low-Temperature Buffer and Impurity Incorporation on the Characteristics of Nitrogen-polar GaN

Effects of Thickness of a Low-Temperature Buffer and Impurity Incorporation on the Characteristics of Nitrogen-polar GaN

MOCVD growth of N-polar GaN on on-axis sapphire substrate: Impact of AlN nucleation layer on GaN surface hillock density

N-polar III-nitride transistors

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