High Al-content AlGaN/GaN MODFETs for ultrahigh performance

Wu, Yifeng; Keller, B.P.; Fini, P.; Keller, S.; Jenkins, T.; Kehias, L.; DenBaars, Steven P.; Mishra, Umesh K.

doi:10.1109/55.658600

Cited by 266 publications

(99 citation statements)

References 9 publications

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“…The unique properties of nitride-based high electron mobility transistors (HEMTs) result from polarization phenomena at the heterostructure QWs and from the nitrides' robust physical parameters, which lead to high output power density, high operation 13 cm À2 , even without doping the barriers [109]. Moreover, by increasing the Al composition in the barrier, the sheet carrier density can be increased further, which is desirable for high-power high-frequency applications [110]. When a thin (of about 7 nm) AlN barrier is used, 2DEG densities could be as high as 5 Â 10 13 cm À2 , which is near the polarization limit [111].…”

Section: Rf Hfetsmentioning

confidence: 99%

GaN Substrates for III-Nitride Devices

2010

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| Despite the rapid commercialization of III-nitride semiconductor devices for applications in visible and ultraviolet optoelectronics and in high-power and high-frequency electronics, their full potential is limited by two primary obstacles: i) a high defect density and biaxial strain due to the heteroepitaxial growth on foreign substrates, which result in lower performance and shortened device lifetime, and ii) a strong built-in electric field due to spontaneous and piezoelectric polarization in the wurtzite structures along the well-established [0001] growth direction for nitrides. Recent advances in the research, development, and commercial production of native GaN substrates with low defect density and high structural and optical quality have opened opportunities to overcome both of these obstacles and have led to significant progress in the development of several optoelectronic and high-power devices. In this paper, the recent achievements in bulk GaN growth development using different approaches are reviewed; comparison of the bulk materials grown in different directions is made; and the current achievements in device performance utilizing native GaN substrate material are summarized.

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Section: Rf Hfetsmentioning

confidence: 99%

GaN Substrates for III-Nitride Devices

2010

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“…Many studies have been performed to improve the performance of devices, such as increasing the Al composition of an AlGaN barrier [2], using a thin AlN spacer layer at the AlGaN/GaN interface [3,4], and replacing the GaN with InGaN as the channel [5,6] and AlGaN with AlInN [7][8][9][10][11][12][13][14][15][16] as the barrier. Among these, the lattice-matched AlInN barrier is considered to be the most promising barrier alternative for improving the HEMT performance.…”

Section: Introductionmentioning

confidence: 99%

The effect of GaN thickness inserted between two AlN layers on the transport properties of a lattice matched AlInN/AlN/GaN/AlN/GaN double channel heterostructure

et al. 2014

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One AlInN/AlN/GaN single channel heterostructure sample and four AlInN/AlN/GaN/AlN/GaN double channel heterostructure samples with different values of the second GaN layer were studied. The interface profiles, crystalline qualities, surface morphologies, and dislocation densities of the samples were investigated using high resolution transmission electron microscopy, atomic force microscopy, and high-resolution X-ray diffraction. Some of the data provided by these measurements were used as input parameters in the calculation of the scattering mechanisms that govern the transport properties of the studied samples. Experimental transport data were obtained using temperature dependent Hall effect measurements (10-300 K) at low (0.5 T) and high (8 T) magnetic fields to exclude the bulk transport from the two-dimensional one. The effect of the thickness of the second GaN layer inserted between two AlN barrier layers on mobility and carrier concentrations was analyzed and the dominant scattering mechanisms in the low and high temperature regimes were determined. It was found that Hall mobility increases as the thickness of GaN increases until 5 nm at a low temperature where interface roughness scattering is observed as one of the dominant scattering mechanisms. When GaN thicknesses exceed 5 nm, Hall mobility tends to decrease again due to the population of the second channel in which the interface becomes worse compared to the other one. From these analyses, 5 nm GaN layer thicknesses were found to be the optimum thicknesses required for high electron mobility.

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“…GaN and its related alloys have the band gaps and optical characteristics suitable for such short wavelengths light sources as blue and ultra-violet light emitting diodes or lasers [1], which have commercial values in the applications of display, lighting, digital information storage and retrieval. In the context of role reversal, these material combinations are also candidates for ultra-violet photodetectors and solar blind detectors.…”

Section: Introductionmentioning

confidence: 99%