Room temperature negative differential resistance characteristics of polar III-nitride resonant tunneling diodes

Bayram, Can; Vashaei, Z.; Razeghi, Manijeh

doi:10.1063/1.3484280

Cited by 51 publications

(49 citation statements)

References 16 publications

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“…33 Crystal lattice expansion and compression depend on these three factors. Poisson's ratio of GaN (the values for the elastic constant for GaN, c 13 and c 33 are 106 GPa and 398 GPa respectively) is measured using (8).…”

Section: Resultsmentioning

confidence: 99%

“…6 Several approaches by previous researchers illustrated the growth of such thin heterostructures on different substrate such as sapphire or free standing/Lateral epitaxial overgrowth (LEO)/Kyma GaN. 7,8 Till now, no significant research has been done for the growth of ultra-thin barrier-well-barrier AlGaN/GaN/AlGaN heterostructure on silicon substrate. Previous several literatures described the growth of GaN on various substrates such as, SiC or sapphire, where SiC has lower lattice mismatch (∼3.3%) along [0001] with GaN, 9 and sapphire has smaller lattice (∼13%) and thermal (∼25.5%) mismatch with GaN.…”

Section: Introductionmentioning

confidence: 99%

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Impact of varying buffer thickness generated strain and threading dislocations on the formation of plasma assisted MBE grown ultra-thin AlGaN/GaN heterostructure on silicon

Chowdhury

Biswas

2015

AIP Advances

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Plasma-assisted molecular beam epitaxy (PAMBE) growth of ultra-thin Al0.2Ga0.8N/GaN heterostructures on Si(111) substrate with three buffer thickness (600 nm/400 nm/200 nm) have been reported. An unique growth process has been developed that supports lower temperature epitaxy of GaN buffer which minimizes thermally generated tensile strain through appropriate nitridation and AlN initiated epitaxy for achieving high quality GaN buffer which supports such ultra-thin heterostructures in the range of 10-15Å. It is followed by investigations of role of buffer thickness on formation of ultra-thin Al0.2Ga0.8N/GaN heterostructure, in terms of stress-strain and threading dislocation (TD). Structural characterization were performed by High-Resolution X-Ray Diffraction (HRXRD), room-temperature Photoluminescence (RT-PL), High Resolution Transmission Electron Microscopy (HRTEM) and Atomic Force Microscopy (AFM). Analysis revealed increasing biaxial tensile stress of 0.6918 ± 0.04, 1.1084, 1.1814 GPa in heterostructures with decreasing buffer thickness of 600, 400, 200 nm respectively which are summed up with residual tensile strain causing red-shift in RT-PL peak. Also, increasing buffer thickness drastically reduced TD density from the order 1010 cm−2 to 108 cm−2. Surface morphology through AFM leads to decrease of pits and root mean square value with increasing buffer thickness which are resulted due to reduction of combined effect of strain and TDs.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Impact of varying buffer thickness generated strain and threading dislocations on the formation of plasma assisted MBE grown ultra-thin AlGaN/GaN heterostructure on silicon

Chowdhury

Biswas

2015

AIP Advances

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“…In recent years, numerous researches have reported that the charge trapping effect introduced by deep-level crystal defects in GaN leads to an evident degradation in negativedifferential-resistance (NDR) characteristic; consequently, a significant decreases of radio frequency power and conversion efficiency in terahertz device operation. 29 We would prefer to predict that charge trapping effect can be weakened by using a BHEI structure in the AlGaN/GaN/AlGaN quantum well.…”

Section: Pl Characterizationmentioning

confidence: 99%

Dislocation blocking by AlGaN hot electron injecting layer in the epitaxial growth of GaN terahertz Gunn diode

Yang

Zhang

et al. 2013

Journal of Applied Physics

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This paper reports an efficient method to improve the crystal quality of GaN Gunn diode with AlGaN hot electron injecting layer (HEI). An evident reduction of screw dislocation and edge dislocation densities is achieved by the strain management and the enhanced lateral growth in high temperature grown AlGaN HEI layer. Compared with the top hot electron injecting layer (THEI) structure, the bottom hot electron injecting layer (BHEI) structure enhances the crystal quality of transit region due to the growth sequence modulation of HEI layer. A high Hall mobility of 2934 cm2/Vs at 77 K, a nearly flat downtrend of Hall mobility at the temperature ranging from 300 to 573 K, a low intensity of ratio of yellow luminescence band to band edge emission, a narrow band edge emission line-width, and a smooth surface morphology are observed for the BHEI structural epitaxy of Gunn diode, which indicates that AlGaN BHEI structure is a promising candidate for fabrication of GaN Gunn diodes in terahertz regime.

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“…For such applications the AlGaN/GaN heterostructure, also, has been widely investigated. [11][12][13] The presence of strain at the AlGaNGaN heterointerface, however, creates piezoelectric polarization charges which cause charge-trapping effects at the heterointerface; this alters the dominant transport mechanism, degrading their tunneling characteristics. 13 The strain-related constraints on use of the Al 0.2 Ga 0.8 N/GaN heterostructure for tunneling applications can be minimized by using In 0.17 Al 0.83 N in place of Al 0.2 Ga 0.8 N. Notably, thin AlGaN/GaN and InAlN/GaN heterostructures improve the mobility of 2DEG by removing alloy scattering; 14,15 such thin InAlN/GaN heterostructures can also be utilized in tunneling barrier applications to deliver improved performance.…”

Section: Introductionmentioning

confidence: 99%

Comparative Structural Characterization of Thin Al0.2Ga0.8 N/GaN and In0.17Al0.83N/GaN Heterostructures Grown on Si(111), by MBE, with Variation of Buffer Thickness

Chowdhury

Borisov

Chow

et al. 2015

Journal of Elec Materi

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We report growth, by plasma-assisted molecular beam epitaxy, of thin Al 0.2 Ga 0.8 N/GaN and In 0.17 Al 0.83 N/GaN heterostructures on Si(111) substrate with three different buffer thickness (600, 400, and 200 nm). Successful growth by critical optimization of growth conditions was followed by comparative characterization of these heterostructures by use of high resolution x-ray diffraction (HRXRD), including reciprocal space mapping (RSM), room-temperature photoluminescence (RT-PL), and high resolution transmission electron microscopy (HRTEM). The effect of different buffer thickness on the threading dislocation (TD) density of a thin 1.5 nm Al 0.2 Ga 0.8 N/In 0.17 Al 0.83 N-1.25 nm GaN-1.5 nm Al 0.2 Ga 0.8 N/In 0.17 Al 0.83 N heterostructure, was also studied. Analysis revealed increasing tensile strain with decreasing buffer thickness for AlGaN-based samples; this was confirmed by the red-shift of the GaN RT-PL peak. Reduced strain in lattice-matched InAlN-based samples resulted in a blue-shift of the GaN RT-PL peak; this was indicative of better crystallographic quality than for the AlGaN/GaN samples, which was proved by XRD-FWHM and RSM results. A substantial reduction of TD density from approximately 10 10 to 10 8 cm À2 with increasing buffer thickness resulted in a smooth thin active region for both thick buffer structures whereas the latticematched InAlN/GaN-based thick buffer resulted in less effect on TD and a smooth and prominent thin active region.

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Room temperature negative differential resistance characteristics of polar III-nitride resonant tunneling diodes

Cited by 51 publications

References 16 publications

Impact of varying buffer thickness generated strain and threading dislocations on the formation of plasma assisted MBE grown ultra-thin AlGaN/GaN heterostructure on silicon

Impact of varying buffer thickness generated strain and threading dislocations on the formation of plasma assisted MBE grown ultra-thin AlGaN/GaN heterostructure on silicon

Dislocation blocking by AlGaN hot electron injecting layer in the epitaxial growth of GaN terahertz Gunn diode

Comparative Structural Characterization of Thin Al0.2Ga0.8 N/GaN and In0.17Al0.83N/GaN Heterostructures Grown on Si(111), by MBE, with Variation of Buffer Thickness

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