Dielectric properties of highly resistive GaN crystals grown by ammonothermal method at microwave frequencies

Křupka, J.; Zając, M.; Kucharski, Robert; Gryglewski, D.

doi:10.1063/1.4944750

Cited by 9 publications

(7 citation statements)

References 10 publications

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“…HEMT structures used in this study (see Figure 1 a) were grown on a 1-inch c-plane, ∼400

m thick, semi-insulating ammonothermal bulk GaN (SI Ammono-GaN) substrates. The resistivity of semi-insulating Ammono-GaN is typically no less than 10

·cm in paralel direction to the c-axis, as measured by frequency domain capacitive technique [ 18 , 19 ], and over 1 × 10

·cm (above the measurement method range) in the perpendicular direction to c-axis, as determined by microwave methods [ 19 , 20 ].…”

Section: Methodsmentioning

confidence: 99%

AlGaN/GaN High Electron Mobility Transistors on Semi-Insulating Ammono-GaN Substrates with Regrown Ohmic Contacts

et al. 2018

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AlGaN/GaN high electron mobility transistors on semi-insulating bulk ammonothermal GaN have been investigated. By application of regrown ohmic contacts, the problem with obtaining low resistance ohmic contacts to low-dislocation high electron mobility transistor (HEMT) structures was solved. The maximum output current was about 1 A/mm and contact resistances was in the range of 0.3–0.6 Ω·mm. Good microwave performance was obtained due to the absence of parasitic elements such as high access resistance.

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“…HEMT structures used in this study (see Figure 1 a) were grown on a 1-inch c-plane, ∼400

m thick, semi-insulating ammonothermal bulk GaN (SI Ammono-GaN) substrates. The resistivity of semi-insulating Ammono-GaN is typically no less than 10

·cm in paralel direction to the c-axis, as measured by frequency domain capacitive technique [ 18 , 19 ], and over 1 × 10

·cm (above the measurement method range) in the perpendicular direction to c-axis, as determined by microwave methods [ 19 , 20 ].…”

Section: Methodsmentioning

confidence: 99%

AlGaN/GaN High Electron Mobility Transistors on Semi-Insulating Ammono-GaN Substrates with Regrown Ohmic Contacts

et al. 2018

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“…Several have been measured by this technique versus temperature and frequency (employing higher-order modes excited in one sample). Results of high resistivity semiconductor measurements, including Si [ 58 , 59 ], GaAs [ 60 ], GaP [ 60 ], SiC [ 61 ], GaN [ 62 ] have already been published. Because the term of the effective dielectric loss tangent depending on conductivity decreases with frequency in a well-known manner (8), the combination of frequency and temperature measurements can separate the dielectric and the conducting terms, even if they are comparable.…”

Section: Microwave Measurements On Semiconductors Conductors and Superconductorsmentioning

confidence: 99%

“…More information on measurements of these silicon samples can be found in the original paper [ 59 ]. Results of the loss tangent determination depending on the dielectric losses for bulk samples of semi-insulating Si [ 58 , 59 ], GaAs [ 60 ], GaP [ 60 ], and GaN (type 1) [ 62 ] are shown in Figure 8 c, while results of the effective loss tangent measurements versus temperature on two samples of GaN are shown in Figure 8 d. Measurements of the effective dielectric loss tangent of GaN have been performed on samples obtained with the ammonothermal growth. Two samples type 1 were doped with transition metal ions as deep acceptors, while sample type 2 was doped with Mg ions as shallow acceptors.…”

Section: Microwave Measurements On Semiconductors Conductors and Superconductorsmentioning

confidence: 99%

“…DC resistivity measurements (green squares) have been performed on another FZ proton irradiated sample. ( c ) The dielectric loss tangent, due to dielectric losses of semi-insulating semiconductors, at the temperature of 25 C. ( d ) The total dielectric loss tangent of two kinds of GaN samples as a function of temperature at a frequency about 15 GHz [ 62 ].…”

Section: Figurementioning

confidence: 99%

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Microwave Measurements of Electromagnetic Properties of Materials

Křupka

2021

Materials

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A review of measurement methods of the basic electromagnetic parameters of materials at microwave frequencies is presented. Materials under study include dielectrics, semiconductors, conductors, superconductors, and ferrites. Measurement methods of the complex permittivity, the complex permeability tensor, and the complex conductivity and related parameters, such as resistivity, the sheet resistance, and the ferromagnetic linewidth are considered. For dielectrics and ferrites, the knowledge of their complex permittivity and the complex permeability at microwave frequencies is of practical interest. Microwave measurements allow contactless measurements of their resistivity, conductivity, and sheet resistance. These days contactless conductivity measurements have become more and more important, due to the progress in materials technology and the development of new materials intended for the electronic industry such as graphene, GaN, and SiC. Some of these materials, such as GaN and SiC are not measurable with the four-point probe technique, even if they are conducting. Measurement fixtures that are described in this paper include sections of transmission lines, resonance cavities, and dielectric resonators.

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“…Highly resistive GaN substrates are required for laterally operating electronic devices like high electron mobility transistors. [1][2][3][4][5][6] The ideal path to high resistivity in a semiconductor is to reduce concentrations of residual impurities. GaN of the highest purity was presented by Refs.…”

Section: Introductionmentioning

confidence: 99%

Iron and manganese as dopants used in the crystallization of highly resistive HVPE-GaN on native seeds

Iwińska

Zając

Łucznik

et al. 2019

Jpn. J. Appl. Phys.

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An influence of doping with iron and manganese on GaN crystallized by halide vapor phase epitaxy is described in this work. This is a continuation of previous work where solid iron was used as a metal precursor and semi-insulating GaN co-doped with manganese and iron was crystallized. In this paper, metals of the highest purity were used. The acceptors (iron and manganese) were incorporated separately in order to compensate unintentional donors present in undoped GaN crystals. Native GaN wafers were used as seeds. The crystallized doped samples were examined in terms of their structural and electrical properties. Concentrations of dopants and unwanted impurities were determined. Iron-doped and Mn-doped GaN, with resistivity at room temperature exceeding 10 7 Ωcm, was presented and compared. It was shown that, at room temperature, for the same acceptor concentration, GaN:Mn crystals present better structural quality and higher resistivity than GaN:Fe.

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Dielectric properties of highly resistive GaN crystals grown by ammonothermal method at microwave frequencies

Cited by 9 publications

References 10 publications

AlGaN/GaN High Electron Mobility Transistors on Semi-Insulating Ammono-GaN Substrates with Regrown Ohmic Contacts

AlGaN/GaN High Electron Mobility Transistors on Semi-Insulating Ammono-GaN Substrates with Regrown Ohmic Contacts

Microwave Measurements of Electromagnetic Properties of Materials

Iron and manganese as dopants used in the crystallization of highly resistive HVPE-GaN on native seeds

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