High-Performance 1-$\mu\hbox{m}$ GaN n-MOSFET With MgO/MgO–$\hbox{TiO}_{2}$ Stacked Gate Dielectrics

Lee, Ko-Tao; Chen, Huang-Chin; Gong, Jeng; Lee, Chia-Tien

doi:10.1109/led.2010.2096196

Cited by 23 publications

(10 citation statements)

References 16 publications

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“…GaN and its related compounds, which have been used for high-temperature high-power RF electronics because of the large critical breakdown fields and high saturation velocities, are now being considered for the post Si CMOS technology. In the past few years, GaN MOSFETs have been demonstrated using MgO, , Al 2 O 3 , HfO 2 , and Ga 2 O 3 (Gd 2 O 3 ) as the gate dielectrics. For pushing the GaN MOS technology, the equivalent oxide thickness (EOT) of the gate dielectric is required to be much less than 1 nm .…”

Section: Introductionmentioning

confidence: 99%

Phase Transformation of Molecular Beam Epitaxy-Grown Nanometer-Thick Gd₂O₃ and Y₂O₃ on GaN

Chang¹,

Wu²,

Lee³

et al. 2013

ACS Appl. Mater. Interfaces

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High quality nanometer-thick Gd₂O₃ and Y₂O₃ (rare-earth oxide, R₂O₃) films have been epitaxially grown on GaN (0001) substrate by molecular beam epitaxy (MBE). The R₂O₃ epi-layers exhibit remarkable thermal stability at 1100 °C, uniformity, and highly structural perfection. Structural investigation was carried out by in situ reflection high energy electron diffraction (RHEED) and ex-situ X-ray diffraction (XRD) with synchrotron radiation. In the initial stage of epitaxial growth, the R₂O₃ layers have a hexagonal phase with the epitaxial relationship of R₂O₃ (0001)(H)<1120>(H)//GaN(0001)(H)<1120>(H). With the increase in R₂O₃ film thickness, the structure of the R₂O₃ films changes from single domain hexagonal phase to monoclinic phase with six different rotational domains, following the R₂O₃ (201)(M)[020](M)//GaN(0001)(H)<1120>(H) orientational relationship. The structural details and fingerprints of hexagonal and monoclinic phase Gd₂O₃ films have also been examined by using electron energy loss spectroscopy (EELS). Approximate 3-4 nm is the critical thickness for the structural phase transition depending on the composing rare earth element.

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Section: Introductionmentioning

confidence: 99%

Phase Transformation of Molecular Beam Epitaxy-Grown Nanometer-Thick Gd₂O₃ and Y₂O₃ on GaN

Chang¹,

Wu²,

Lee³

et al. 2013

ACS Appl. Mater. Interfaces

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“…The I on /I off ratio of the present La 2 O 3 /Al 2 O 3 -MOSHEMT is also superior to LaAlO 3 /SiO 2 -MOSFET 10 and MgO/TiO 2 -GaN MOSFET. 11 In addition, the V th values of samples A-C are −2.8 V, −5.3 V, and −5.8 V, which were extracted from the (I DS ) 0.5 -V GS characteristics as shown in Fig. 6.…”

Section: Resultsmentioning

confidence: 99%

“…High dielectric constant (k) materials such as Al 2 O 3, 5,6 HfO 2, 7 TiO 2, 8 and ZrO 2 9 are very promising for providing low equivalent oxide thickness (EOT) and good gate insulating. In addition, stacked gate dielectric structures such as LaAlO 3 /SiO 2 , 10 MgO/TiO 2 , 11 Si 3 N 4 /Al 2 O 3 , 12 HfO 2 /Al 2 O 3, 13,14 and SiO 2 /Al 2 O 3 15 were studied to further enhance the gate insulating capability. Our previous work has also demonstrated AlGaN/GaN MOS-HEMTs 13 with stacked HfO 2 /Al 2 O 3 gate dielectrics by using separate fabrication techniques.…”

mentioning

confidence: 99%

Comparative Studies on AlGaN/GaN MOS-HEMTs with Stacked La₂O₃/Al₂O₃Dielectric Structures

Liu

Lee

Liao

et al. 2014

ECS J. Solid State Sci. Technol.

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This work provides comparative studies of AlGaN/GaN MOS-HEMT with the devised stacked La 2 O 3 /Al 2 O 3 dielectric structure with respect to a conventional Schottky-gate HEMT and a reference La 2 O 3 -dielectric MOS-HEMT, which were all fabricated on the identical epitaxial layers. The La 2 O 3 /Al 2 O 3 stacked dielectrics are formed by using RF magnetron sputter/H 2 O 2 oxidization. Transmission electron microscopy (TEM), capacitance-voltage (C-V) measurement with different frequency, and low-frequency noise (LFN) analysis were used to study the interface and oxide quality. Comprehensive studies on electrical and thermal stability characteristics have been performed. Improved transconductance gain (g m ), current drive, breakdown, and thermal stability at 300-480 K are achieved in the present MOS-HEMT design.Gallium nitride (GaN) HEMTs have demonstrated promising potential in high-power and high-frequency applications. 1,2 In general, the GaN HEMTs use Schottky contact as the gate electrode. The gate insulating capability is dependent on the barrier height between the gate metal and the semiconductor barrier. The Schottky contact has the advantage of easy fabrication. However, the problem such as Fermi level pinning (FLP) reduces the Schottky barrier height which would seriously degrade the gate leakage. The MOS-gate structure has been proposed to enhance the gate insulating by reducing the gate leakage. 3 Furthermore, the dielectric material can be used as the passivation layer at the same time to resolve the RF drain current collapse 4 problems. High dielectric constant (k) materials such as Al 2 O 3, 5,6 HfO 2, 7 TiO 2, 8 and ZrO 2 9 are very promising for providing low equivalent oxide thickness (EOT) and good gate insulating. In addition, stacked gate dielectric structures such as LaAlO 15 were studied to further enhance the gate insulating capability. Our previous work has also demonstrated AlGaN/GaN MOS-HEMTs 13 with stacked HfO 2 /Al 2 O 3 gate dielectrics by using separate fabrication techniques. La 2 O 3 has competitive dielectric constant (20∼25), larger bandgap (∼6 eV), and better thermal stability than HfO 2 . 16,17 This work employs H 2 O 2 oxidation technique to grow Al 2 O 3 on the AlGaN barrier. Then, the high-k La 2 O 3 is sputtered on the Al 2 O 3 liner to form the stackeddielectric design for the present La 2 O 3 /Al 2 O 3 /AlGaN/ GaN MOS-HEMT. The oxide quality of La 2 O 3 /Al 2 O 3 stacks of the MOS-gate structure is studied. Improved electrical performances of the present La 2 O 3 /Al 2 O 3 /AlGaN/GaN MOS-HEMT are also investigated in comparison with a reference La 2 O 3 /AlGaN/GaN MOS-HEMT and a conventional Schottky-gate device, which were all fabricated on the identical epitaxial structure. Material Growth and Device FabricationThe epitaxial structure of the studied AlGaN/GaN MOS-HEMTs, as shown in Fig. 1a, is grown by the metal organic chemical vapor deposition (MOCVD) system. On the SiC substrate, a 30-nm thick low-temperature-grown GaN is the nucleation layer. The 2-μm thick GaN an...

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“…To provide good gate insulation and maintain low equivalent oxide thickness (EOT) for vertical scaling different high‐ k materials such as Al 2 O 3 , HfO 2 , TiO 2 , and ZrO 2 are reported in various literatures [10]. To enhance the gate insulating capabilities, stacked gate dielectric structures such as LaAlO 3 /SiO 2 [11], MgO/TiO 2 , [12] Si 3 N 4 /Al 2 O 3 , [13] HfO 2 /Al 2 O 3 , [14] and SiO 2 /Al 2 O 3 [15] were also reported in various literatures. To reduce the parasitic resistance and capacitance T‐shaped gate geometry is used in most of the literatures.…”

Section: Introductionmentioning

confidence: 99%

Compact thermal noise model for enhancement mode N‐polar GaN MOS‐HEMT including 2DEG density solution with two sub‐bands

Panda

Lenka

2018

IET Circuits, Devices & Systems

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A 135 nm gate length-based low noise enhancement mode N-polar double deck T-shaped gate Gallium Nitride (GaN) Metal Oxide Semiconductor (MOS)-high electron mobility transistor with double insulating layer of high-k dielectrics ZrO 2 /HfO 2 is proposed. The device exhibits maximum transconductance of 0.55 S/mm, maximum drain current density of 1.4 A/mm and minimum noise figure (NF min) of 0.72 dB at 20 GHz. A compact model for Two Dimensional Electron Gas (2DEG) density is developed by explicit solution of surface potential and Fermi level by considering first two sub-bands of triangular quantum well without using any numerical methods. Based on the surface potential drain current, intrinsic charge, gate capacitance, small signal and thermal noise models are developed. To validate the proposed numerical model, the results are calibrated with TCAD device simulation results and available experimental data from literatures.

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High-Performance 1-$\mu\hbox{m}$ GaN n-MOSFET With MgO/MgO–$\hbox{TiO}_{2}$ Stacked Gate Dielectrics

Cited by 23 publications

References 16 publications

Phase Transformation of Molecular Beam Epitaxy-Grown Nanometer-Thick Gd₂O₃ and Y₂O₃ on GaN

Phase Transformation of Molecular Beam Epitaxy-Grown Nanometer-Thick Gd₂O₃ and Y₂O₃ on GaN

Comparative Studies on AlGaN/GaN MOS-HEMTs with Stacked La₂O₃/Al₂O₃Dielectric Structures

Compact thermal noise model for enhancement mode N‐polar GaN MOS‐HEMT including 2DEG density solution with two sub‐bands

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High-Performance 1-$\mu\hbox{m}$ GaN n-MOSFET With MgO/MgO–$\hbox{TiO}_{2}$ Stacked Gate Dielectrics

Cited by 23 publications

References 16 publications

Phase Transformation of Molecular Beam Epitaxy-Grown Nanometer-Thick Gd2O3 and Y2O3 on GaN

Phase Transformation of Molecular Beam Epitaxy-Grown Nanometer-Thick Gd2O3 and Y2O3 on GaN

Comparative Studies on AlGaN/GaN MOS-HEMTs with Stacked La2O3/Al2O3Dielectric Structures

Compact thermal noise model for enhancement mode N‐polar GaN MOS‐HEMT including 2DEG density solution with two sub‐bands

Contact Info

Product

Resources

About

Phase Transformation of Molecular Beam Epitaxy-Grown Nanometer-Thick Gd₂O₃ and Y₂O₃ on GaN

Phase Transformation of Molecular Beam Epitaxy-Grown Nanometer-Thick Gd₂O₃ and Y₂O₃ on GaN

Comparative Studies on AlGaN/GaN MOS-HEMTs with Stacked La₂O₃/Al₂O₃Dielectric Structures