Effects of Cl2-Based Inductively Coupled Plasma Etching of AlGaN on Interface Properties of Al2O3/AlGaN/GaN Heterostructures

Yatabe, Zenji; Hori, Yuichi; Kim, Sungsik; Hashizume, Tamotsu

doi:10.7567/apex.6.016502

Cited by 26 publications

(26 citation statements)

References 22 publications

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“…16,24,29 However as shown in Fig. 9, the values of capture cross section remained similar among these samples.…”

Section: Discussionmentioning

confidence: 58%

“…2, it follows that the sample with ICP etching exhibited increased C total and significant V th shift in the C-V curve compared with the sample without ICP etching due to the reduced AlGaN layer thickness. It was shown from transmission electron microscopy observation 29 that the sample without etching exhibited a flat Al 2 O 3 /AlGaN interface, indicating the low-energy and layerby-layer characteristics of the ALD process. On the contrary, the ICP etching resulted in the slight roughening of the interface, creating monolayer-level steps at the AlGaN surface.…”

Section: Methodsmentioning

confidence: 99%

“…2 sample exhibited the higher interface state density probably due to interface disorder. 16,24,29 The ᭝V th in C-V characteristics was measured in the following manner. The measurement steps and the corresponding band diagrams are schematically shown in Figs.…”

Section: Methodsmentioning

confidence: 99%

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Characterization of capture cross sections of interface states in dielectric/III-nitride heterojunction structures

Matys

Stoklas

Kuzmı́k

et al. 2016

Journal of Applied Physics

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Articles you may be interested inWe performed, for the first time, quantitative characterization of electron capture cross sections r of the interface states at dielectric/III-N heterojunction interfaces. We developed a new method, which is based on the photo-assisted capacitance-voltage measurements using photon energies below the semiconductor band gap. The analysis was carried out for AlGaN/GaN metal-insulatorsemiconductor heterojunction (MISH) structures with Al 2 O 3 , SiO 2 , or SiN films as insulator deposited on the AlGaN layers with Al content (x) varying over a wide range of values. Additionally, we also investigated an Al 2 O 3 /InAlN/GaN MISH structure. Prior to insulator deposition, the AlGaN and InAlN surfaces were subjected to different treatments. We found that r for all these structures lies in the range between 5 Â 10 À19 and 10 À16 cm 2 . Furthermore, we revealed that r for dielectric/ Al x Ga 1Àx N interfaces increases with increasing x. We showed that both the multiphonon-emission and cascade processes can explain the obtained results. Published by AIP Publishing.

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“…16,24,29 However as shown in Fig. 9, the values of capture cross section remained similar among these samples.…”

Section: Discussionmentioning

confidence: 58%

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Characterization of capture cross sections of interface states in dielectric/III-nitride heterojunction structures

Matys

Stoklas

Kuzmı́k

et al. 2016

Journal of Applied Physics

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“…3(a), the initial HEMT structure has a 34-nm-thick AlGaN layer. After the ICP etching, the AlGaN thickness was reduced to 27 nm, 70) causing an increase in C TOTAL and a pronounced V th shift in the C-V curve. By assuming interface state density distributions indicated by the solid lines in Fig.…”

Section: Estimation Of the State Density Distribution At Al 2 O 3 / Amentioning

confidence: 99%

Characterization of electronic states at insulator/(Al)GaN interfaces for improved insulated gate and surface passivation structures of GaN-based transistors

Yatabe

Hori

et al. 2014

Jpn. J. Appl. Phys.

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This paper presents a systematic characterization of electronic states at insulators/(Al)GaN interfaces, particularly focusing on insulator/AlGaN/ GaN structures. First, we review important results reported for GaN metal-insulator-semiconductor (MIS) structures. SiO 2 is an attractive material for MIS transistor applications due to its large bandgap and high chemical stability. In-situ SiN x is effective for improving the operation stability of high electron mobility transistors (HEMTs). Meanwhile, Al 2 O 3 /GaN structures have high band offsets and low interface state densities, which are also desirable for insulated gate applications. We have proposed a calculation method for describing capacitance-voltage (C-V) characteristics of HEMT MIS structures for evaluating electronic state properties at the insulator/AlGaN interfaces. To evaluate near-midgap states at insulator/ AlGaN interfaces, a photo-assisted C-V technique using photon energies less than the bandgap of GaN has been developed. Using the calculation in conjunction with the photo-assisted C-V technique, we estimate interface state density distributions at the Al 2 O 3 /AlGaN interfaces.

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“…It means that only a limited number of the interface states can be detected during the standard C-V measurements. Although several groups have proposed new methods to characterize electronic states in the MOS-HEMT structures, [14][15][16][17] there have been few reports on MOS interface state densities of the GaN-based MOS-HEMTs and their relationship to the resulting electrical properties has not been discussed in detail.…”

Section: Introductionmentioning

confidence: 99%

Characterization of interface states in Al2O3/AlGaN/GaN structures for improved performance of high-electron-mobility transistors

Hori¹,

Yatabe²,

Hashizume³

2013

Journal of Applied Physics

156

120

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We have investigated the relationship between improved electrical properties of Al 2 O 3 /AlGaN/GaN metal-oxide-semiconductor high-electron-mobility transistors (MOS-HEMTs) and electronic state densities at the Al 2 O 3 /AlGaN interface evaluated from the same structures as the MOS-HEMTs. To evaluate Al 2 O 3 /AlGaN interface state densities of the MOS-HEMTs, two types of capacitance-voltage (C-V) measurement techniques were employed: the photo-assisted C-V measurement for the near-midgap states and the frequency dependent C-V characteristics for the states near the conduction-band edge. To reduce the interface states, an N 2 O-radical treatment was applied to the AlGaN surface just prior to the deposition of the Al 2 O 3 insulator. As compared to the sample without the treatment, the N 2 O-radical treated Al 2 O 3 /AlGaN/GaN structure showed smaller frequency dispersion of the C-V curves in the positive gate bias range. The state densities at the Al 2 O 3 /AlGaN interface were estimated to be 1 Â 10 12 cm À2 eV À1 or less around the midgap and 8 Â 10 12 cm À2 eV À1 near the conduction-band edge. In addition, we observed higher maximum drain current at the positive gate bias and suppressed threshold voltage instability under the negative gate bias stress even at 150 C. Results presented in this paper indicated that the N 2 O-radical treatment is effective both in reducing the interface states and improving the electrical properties of the Al 2 O 3 /AlGaN/GaN MOS-HEMTs. V C 2013 AIP Publishing LLC. [http://dx

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Effects of Cl₂-Based Inductively Coupled Plasma Etching of AlGaN on Interface Properties of Al₂O₃/AlGaN/GaN Heterostructures

Cited by 26 publications

References 22 publications

Characterization of capture cross sections of interface states in dielectric/III-nitride heterojunction structures

Characterization of capture cross sections of interface states in dielectric/III-nitride heterojunction structures

Characterization of electronic states at insulator/(Al)GaN interfaces for improved insulated gate and surface passivation structures of GaN-based transistors

Characterization of interface states in Al2O3/AlGaN/GaN structures for improved performance of high-electron-mobility transistors

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