Enhancement in Electron Field Emission of Microcrystalline Diamond Films upon Iron Coating and Annealing Processes

Huang, Pin-Chang; Shih, Wen–Ching; Chen, Huang-Chin; Lin, I‐Nan

doi:10.7567/jjap.50.08ke04

Cited by 44 publications

(7 citation statements)

References 19 publications

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“…Various oxides, such as SiO 2 , SiN x , Al 2 O 3 , AlSiO x , HfO 2 and Al 2 O 3 /HfO 2 laminates, have been found to act as gate insulators [1][2][3][4][5][6][7][8][9][10][11]. Among these, Al 2 O 3 is one of the leading candidate materials because of its large bandgap (8.8 eV), a high dielectric constant k (∼8) and a high breakdown field, and because it has a more stable amorphous structure at higher temperatures [12][13][14]. Al 2 O 3 films for transistor applications are typically fabricated using atomic layer deposition (ALD) with the trimethylaluminum (TMA) precursor and H 2 O oxidant gas.…”

Section: Introductionmentioning

confidence: 99%

Characteristics of Al₂O₃/native oxide/n-GaN capacitors by post-metallization annealing

Yuge

Nabatame

Irokawa

et al. 2019

Semicond. Sci. Technol.

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This work investigated characteristics of Al 2 O 3 /native oxide/n-GaN MOS capacitors by postmetallization annealing (PMA). A native oxide interlayer which composed of εand γ-Ga 2 O 3 phases (Native oxide) and the reduced amount of one (Reduced) on n-GaN were prepared by cleaning only a sulfuric acid peroxide mixture (SPM) and both SPM and buffered hydrofluoric acid, respectively. The effect of trimethylaluminum precursor on removal of a native oxide layer was not observed during Al 2 O 3 deposition using atomic layer deposition. An as-grown capacitor (Native oxide) exhibited a small flatband voltage (V fb ) hysteresis of ∼30 mV and a large frequency dispersion, suggesting that the initial growth of the Al 2 O 3 resulted in the formation of electrical defects on the GaN surface. Both the V fb hysteresis and frequency dispersion were drastically improved by PMA of the device at 300 °C. The positive fixed charge values (Q IL ) estimated from the relationships between capacitance equivalent thickness and V fb were +6.1×10 12 and +0.4-1.0×10 12 cm −2 for as-grown and PMA-processed capacitors in the PMA temperature range of 300 °C-600 °C, respectively. The interface state density (D it ) determined using a conductance method was also significantly reduced (by an order of magnitude) after PMA processing at 300 °C. These trends in the Q IL and D it data were observed in both the Native oxide and Reduced capacitors, indicating that this interlayer does not greatly affect fixed charge generation at the Al 2 O 3 /native oxide and Al 2 O 3 /modified native oxide interfaces. As a result, two types of treatments result in insignificant difference in the electrical properties of the capacitors.

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Section: Introductionmentioning

confidence: 99%

Characteristics of Al₂O₃/native oxide/n-GaN capacitors by post-metallization annealing

Yuge

Nabatame

Irokawa

et al. 2019

Semicond. Sci. Technol.

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“…To overcome these problems, metal-oxide-semiconductor (MOS) gate stacks for AlGaN/GaN HFETs with deposited dielectric films have been studied by many groups. [5][6][7][8][9][10][11][12][13][14][15] Intensive studies on various insulating materials, such as SiO 2 , [5][6][7] and Al 2 O 3 , 8,[10][11][12][13][14] and research comparing them, 9,15) have been conducted with the goal of enabling gate dielectric applications for AlGaN/GaN MOS-HFETs, in which the electrical properties of the insulating films and the insulator/ semiconductor heterointerfaces are subjects of great importance. This is because dielectric breakdown of the gate insulators causes fatal problems, and charge injection into the insulators results in threshold voltage (V th ) instability in MOS devices.…”

Section: Introductionmentioning

confidence: 99%

“…Regarding Al 2 O 3 dielectrics, although recent progress in atomic layer deposition (ALD) allows us to form high-quality ALD-Al 2 O 3 films, charge injection into Al 2 O 3 causing V th instability and need for careful interface engineering have been indicated. 10,11) A recent theoretical study also reported that the complexes of oxygen and aluminum vacancies (V o V Al complexes) responsible for negative fixed charge in Al 2 O 3 are inevitably formed by electrical stressing under positive gate bias conditions. 16) Thus, more research should be conducted into the development of gate insulators for AlGaN/GaN-based MOS devices with a focus on material selection and interface engineering.…”

Section: Introductionmentioning

confidence: 99%

Mobility enhancement in recessed-gate AlGaN/GaN MOS-HFETs using an AlON gate insulator

Hosoi

Watanabe

Nozaki

et al. 2019

Jpn. J. Appl. Phys.

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We demonstrated the advantage of aluminum oxynitride (AlON) gate insulator in enhancing the performance of recessed-gate AlGaN/GaN-based metal-oxide-semiconductor heterojunction field-effect transistors (MOS-HFETs) fabricated with reactive ion etching. The AlON deposition on the recessed-gate structures was found to mitigate the damage of recess etching on the GaN and AlGaN surfaces, enabling a simple gate recess process in the device fabrication. Consequently, a high field-effect mobility of 259 cm 2 V −1 s −1 , together with normally off operation, was achieved for the recessed-gate AlGaN/GaN MOS-HFETs with the AlON gate insulator. Temperature dependence of the transconductance of the fabricated devices revealed that carrier transport in the channel was mostly dominated by phonon scattering, indicating excellent interface quality between the AlON insulator and the recess-etched AlGaN surfaces.

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“…Al 2 O 3 has been commonly examined so far as the gate insulator of AlGaN/GaN HFET, since it exhibits relatively small hysteresis in the gate-transfer current-voltage characteristics. [25][26][27] The high permittivity helps to provide better reliability of the gate by increasing the insulator thickness, maintaining the high transconductances. However, hysteresis in the gate-transfer characteristics has been a technical issue for the use of Al 2 O 3 considering the practical switching applications.…”

Section: Interfacial Properties Of Mis-gatementioning

confidence: 99%

GaN power devices: current status and future challenges

Ueda

2019

Jpn. J. Appl. Phys.

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The status and challenges in the development of GaN power devices are reviewed. At present, normally-off gate injection transistors (GITs) on Si are commercially available. The updated structure known as a hybrid-drain-embedded GIT provides superior reliability that contributes to the stable operation of compact power switching systems with high efficiency. The fabricated vertical GaN transistor on GaN as a future challenge demonstrates extremely low specific on-state resistance and high breakdown voltage. Metal-insulator-semiconductor-gate GaN transistor is also a technical challenge for faster switching, since it would give greater freedom of gate driving as a result of both high threshold voltage and widened gate voltage swing. Normally-off operation free from hysteresis in the current–voltage characteristics is confirmed in a recessed-gate AlGaN/GaN heterojunction field effect transistor using AlON as a gate insulator. Fast switching characteristics are experimentally confirmed for both of the newly developed GaN devices, indicating their great potential for practical use.

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Enhancement in Electron Field Emission of Microcrystalline Diamond Films upon Iron Coating and Annealing Processes

Cited by 44 publications

References 19 publications

Characteristics of Al₂O₃/native oxide/n-GaN capacitors by post-metallization annealing

Characteristics of Al₂O₃/native oxide/n-GaN capacitors by post-metallization annealing

Mobility enhancement in recessed-gate AlGaN/GaN MOS-HFETs using an AlON gate insulator

GaN power devices: current status and future challenges

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Enhancement in Electron Field Emission of Microcrystalline Diamond Films upon Iron Coating and Annealing Processes

Cited by 44 publications

References 19 publications

Characteristics of Al2O3/native oxide/n-GaN capacitors by post-metallization annealing

Characteristics of Al2O3/native oxide/n-GaN capacitors by post-metallization annealing

Mobility enhancement in recessed-gate AlGaN/GaN MOS-HFETs using an AlON gate insulator

GaN power devices: current status and future challenges

Contact Info

Product

Resources

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Characteristics of Al₂O₃/native oxide/n-GaN capacitors by post-metallization annealing

Characteristics of Al₂O₃/native oxide/n-GaN capacitors by post-metallization annealing