Interface trap evaluation of Pd/Al<sub>2</sub>O<sub>3</sub>/GaN metal oxide semiconductor capacitors and the influence of near-interface hydrogen

Long, Rathnait D.; Jackson, Christine E.; Yang, Jason; Hazeghi, Arash; Hitzman, C. J.; Majety, Sridhar; Arehart, Aaron R.; Nishi, Yoshio; P., T.; Ringel, S. A.; McIntyre, Paul C.

doi:10.1063/1.4827102

Cited by 60 publications

(49 citation statements)

References 21 publications

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“…[10][11][12][13][14][15][16] As a consequence, there is still a lack of understanding of interface state fundamental properties at dielectric/III-N heterojunction interfaces, especially their dynamic trapping/emitting behavior expressed in terms of capture cross sections. Furthermore, it should be noted that, as a matter of fact, there is just only one report 17 about the values of the capture cross section for dielectric/ III-N heterojunction interfaces.…”

Section: Introductionmentioning

confidence: 99%

“…[6][7][8][9][10] In order to obtain a good IG structure, suitable insulating materials such as Al 2 O 3 , SiO 2 , and SiN ensuring a large band offset and high permittivity are widely applied. [11][12][13] Furthermore, the chosen insulator material should provide a high quality, stable insulator/semiconductor interface with a low density of interface electronic states. Because of the strong impact of these states on the performance and reliability of HEMTs, monitoring the dynamical properties of insulator/semiconductor interfaces is highly desirable.…”

Section: Introductionmentioning

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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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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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“…Similar anneal processes have been shown to reduce both D it and fixed charge in dielectric/GaN structures. 18,20 To characterize the impact of interface states on the terminal characteristics in these capacitors, C-V dispersion measurements were performed using an Agilent E4980A LCR meter for frequencies of 0.1, 1, 10, 100, and 1000 kHz. To quantify D it , CC-DLTS and CC-DLOS were employed to probe interface states across the GaN bandgap.…”

Section: Methodsmentioning

confidence: 99%

“…CC-DLOS was performed with light energies ranging from 1.5 to 3.5 eV, with increments of 0.02 eV, allowing for determination of interface state density near mid-gap and near the valance band maximum (E V ). 20,22 Samples were produced for XPS analysis by following the same general preparation process, but limiting the Al 2 O 3 deposition to only 24 ALD cycles for a nominal film thickness of 2.0 nm. These thin Al 2 O 3 samples were left as-deposited (i.e.…”

Section: Methodsmentioning

confidence: 99%

Impact of Surface Treatment on Interface States of ALD Al₂O₃/GaN Interfaces

Jackson

Arehart

Grassman

et al. 2017

ECS J. Solid State Sci. Technol.

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Two surface treatments of GaN, prior to atomic layer deposition (ALD) of Al 2 O 3 , were compared to investigate electronic and chemical interface properties: (1) HCl followed by HF and (2) NH 4 OH. Constant capacitance deep level transient and optical spectroscopies (CC-DLTS/CC-DLOS) and X-ray photoelectron spectroscopy (XPS) were used to study the impact of the surface treatments on the interface state density (D it ) and the chemical composition of the Al 2 O 3 /GaN interface, respectively. It was determined that the HCl/HF treatment resulted in 3-10 times higher D it near the GaN conduction band, while the NH 4 OH treatment resulted in nearly 10 times higher D it deeper in the GaN bandgap. XPS revealed that the HCl/HF treatment left residual adsorbed fluorine atoms at the interface and that the NH 4 OH treatment resulted in a higher concentration of carbon near the Al 2 O 3 /GaN interface. These results are discussed in relation to the relevant literature in attempt to understand the relationship between the chemical composition at the interface and the observed differences in D GaN metal-insulator-semiconductor high electron mobility transistors (MISHEMTs) are typically used for power electronics applications, and being considered for highly-scaled and enhancementmode operation in radio-frequency (RF) applications. In these applications, a metal-insulator-semiconductor (MIS) device structure can result in decreased gate leakage current and higher breakdown voltages versus the traditional Schottky-based HEMT structure. However, the insulator-semiconductor interface can lead to high concentrations of interface states that can negatively affect device performance and reliability.1-3 Thus, various groups have focused on improving possible gate dielectrics to reduce surface states and decrease gate leakage while maintaining small equivalent oxide thicknesses. Al 2 O 3 has, in particular, received much attention as a possible gate dielectric because of its potential to provide low leakage and low interface state densities. [4][5][6][7] Nonetheless, prior work indicates that the initial conditions of the GaN surface can significantly influence the quality of the resultant interface.8 Processes to clean the GaN surface have been a topic of research for the last two decades, although early studies primarily focused on preparing the surface for metallization; 9-13 this extensive work was well summarized by Long et al.14 More recently, the topic of surface treatment before dielectric deposition has become a topic of interest, as the search for optimal dielectric materials for use with the GaN material system has grown. 15,16 Of particular concern in these studies, was removal of oxides and organics from the surface. A 1999 study by Koyama et al. compared a combined HCl and HF treatment to a NH 4 OH treatment using XPS, showing that both treatments resulted in oxide removal.12 However, reports have conflicted regarding which of these two results in lower carbon concentration. 13,16 In the broader GaN-related literatu...

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“…Since surface and interface states are strongly process-dependent, the gate insulator process must be carefully optimized. It was reported that the insulator itself and interface conditions between insulator and semiconductor surface could be improved by appropriate post-annealing processes [8][9][10][11][12]. In this study, we investigated the effects of forming gas post metallization annealing (PMA) on recessed AlGaN/GaN-on-Si MOSHFET with ICPCVD SiO 2 gate oxide.…”

Section: Introductionmentioning

confidence: 99%

Forming Gas Post Metallization Annealing of Recessed AlGaN/GaN-on-Si MOSHFET

Lee¹,

Park²,

Lee³

et al. 2015

JSTS:Journal of Semiconductor Technology and Science

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Abstract-In this study, the effects of forming gas post metallization annealing (PMA) on recessed AlGaN/GaN-on-Si MOSHFET were investigated. The device employed an ICPCVD SiO 2 film as a gate oxide layer on which a Ni/Au gate was evaporated. The PMA process was carried out at 350 o C in forming gas ambient. It was found that the device instability was improved with significant reduction in interface trap density by forming gas PMA.Index Terms-AlGaN/GaN heterostructure, forming gas annealing, interface trap density, MOSHFET, post metallization annealing

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Interface trap evaluation of Pd/Al₂O₃/GaN metal oxide semiconductor capacitors and the influence of near-interface hydrogen

Cited by 60 publications

References 21 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

Impact of Surface Treatment on Interface States of ALD Al₂O₃/GaN Interfaces

Forming Gas Post Metallization Annealing of Recessed AlGaN/GaN-on-Si MOSHFET

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Interface trap evaluation of Pd/Al2O3/GaN metal oxide semiconductor capacitors and the influence of near-interface hydrogen

Cited by 60 publications

References 21 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

Impact of Surface Treatment on Interface States of ALD Al2O3/GaN Interfaces

Forming Gas Post Metallization Annealing of Recessed AlGaN/GaN-on-Si MOSHFET

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Interface trap evaluation of Pd/Al₂O₃/GaN metal oxide semiconductor capacitors and the influence of near-interface hydrogen

Impact of Surface Treatment on Interface States of ALD Al₂O₃/GaN Interfaces