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Zhang, H., Persson, I., Chen, J.-T., Papamichail, A., Tran, D., Persson, P. O., . . . Darakchieva, V. (2023). Polarity Control by Inversion Domain Suppression in N-Polar III-Nitride Heterostructures. Crystal Growth & Design, 23(2), 1049-1056
Open this publication in new window or tab >>Polarity Control by Inversion Domain Suppression in N-Polar III-Nitride Heterostructures
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2023 (English)In: Crystal Growth & Design, ISSN 1528-7483, E-ISSN 1528-7505, Vol. 23, no 2, p. 1049-1056Article in journal (Refereed) Published
Abstract [en]

Nitrogen-polar III-nitride heterostructures offer advantages over metal-polar structures in high frequency and high power applications. However, polarity control in III-nitrides is difficult to achieve as a result of unintentional polarity inversion domains (IDs). Herein, we present a comprehensive structural investigation with both atomic detail and thermodynamic analysis of the polarity evolution in low-and high-temperature AlN layers on on-axis and 4 degrees off-axis carbon-face 4H-SiC (000 (1) over bar) grown by hot-wall metal organic chemical vapor deposition. A polarity control strategy has been developed by variation of thermodynamic Al supersaturation and substrate misorientation angle in order to achieve the desired growth mode and polarity. We demonstrate that IDs are completely suppressed for high-temperature AlN nucleation layers when a step-flow growth mode is achieved on the off-axis substrates. We employ this approach to demonstrate high quality N-polar epitaxial AlGaN/GaN/AlN heterostructures.

Place, publisher, year, edition, pages
AMER CHEMICAL SOC, 2023
National Category
Condensed Matter Physics
Identifiers
urn:nbn:se:liu:diva-191983 (URN)10.1021/acs.cgd.2c01199 (DOI)000923282200001 ()
Note

Funding Agencies|Swedish Governmental Agency for Innovation Systems (VINNOVA) [2022-03139]; Lund University; Linkoeping University; Chalmers University of Technology; Ericsson; Epiluvac; FMV; Gotmic; Hexagem; Hitachi Energy; On Semiconductor; Region Skane; Saab; SweGaN; UMS; Volvo Cars; Swedish Research Council VR [2016-00889, 2022-04812]; Swedish Foundation for Strategic Research [RIF14-055, EM16-0024]; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoeping University, Faculty Grant SFO Mat LiU [2009-00971]

Available from: 2023-02-28 Created: 2023-02-28 Last updated: 2023-12-28
Gogova, D., Ghezellou, M., Tran, D. Q., Richter, S., Papamichail, A., ul-Hassan, J., . . . Darakchieva, V. (2022). Epitaxial growth of β-Ga2O3 by hot-wall MOCVD. AIP Advances, 12(5), Article ID 055022.
Open this publication in new window or tab >>Epitaxial growth of β-Ga2O3 by hot-wall MOCVD
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2022 (English)In: AIP Advances, E-ISSN 2158-3226, Vol. 12, no 5, article id 055022Article in journal (Refereed) Published
Abstract [en]

The hot-wall metalorganic chemical vapor deposition (MOCVD) concept, previously shown to enable superior material quality and high performance devices based on wide bandgap semiconductors, such as Ga(Al)N and SiC, has been applied to the epitaxial growth of beta-Ga2O3. Epitaxial beta-Ga2O3 layers at high growth rates (above 1 mu m/h), at low reagent flows, and at reduced growth temperatures (740 degrees C) are demonstrated. A high crystalline quality epitaxial material on a c-plane sapphire substrate is attained as corroborated by a combination of x-ray diffraction, high-resolution scanning transmission electron microscopy, and spectroscopic ellipsometry measurements. The hot-wall MOCVD process is transferred to homoepitaxy, and single-crystalline homoepitaxial beta-Ga2O3 layers are demonstrated with a 201 rocking curve width of 118 arc sec, which is comparable to those of the edge-defined film-fed grown (201) beta-Ga2O3 substrates, indicative of similar dislocation densities for epilayers and substrates. Hence, hot-wall MOCVD is proposed as a prospective growth method to be further explored for the fabrication of beta-Ga2O3.

Place, publisher, year, edition, pages
AIP Publishing, 2022
National Category
Condensed Matter Physics
Identifiers
urn:nbn:se:liu:diva-185208 (URN)10.1063/5.0087571 (DOI)000797911600007 ()
Funder
Swedish Energy Agency, P45396-1Vinnova, 2016-05190Swedish Research Council, 2016-00889Swedish Research Council, 2017-03714Knut and Alice Wallenberg Foundation, 2018.0071
Note

Funding: Swedish Energy Agency [P45396-1]; Swedish Governmental Agency for Innovation Systems (VINNOVA) [2016-05190]; Ericsson; Gotmic; Swedish Research Council VR [2016-00889, 2017-03714]; Swedish Foundation for Strategic Research [RIF14-055, RIF14-074, EM16-0024]; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University; SFO Mat LiU [2009-00971]; National Science Foundation (NSF); NSF [DMR 1808715]; Linkoeping University [OIA-2044049]; NSF/EPSCoR RII Track-1: Emergent Quantum Materials and Technologies (EQUATE); Chalmers University of Technology [FA9550-18-1-0360, FA9550-19-S-0003, FA9550-21-1-0259]; Air Force Office of Scientific Research; Epiluvac; KAW Foundation; FMV; Hexagem; Hitachi Energy; On Semiconductor; Saab; SweGaN; UMS

Available from: 2022-05-18 Created: 2022-05-18 Last updated: 2023-03-28Bibliographically approved
Delgado Carrascon, R., Richter, S., Nawaz, M., Paskov, P. P. & Darakchieva, V. (2022). Hot-Wall MOCVD for High-Quality Homoepitaxy of GaN: Understanding Nucleation and Design of Growth Strategies. Crystal Growth & Design, 22(12), 7021-7030
Open this publication in new window or tab >>Hot-Wall MOCVD for High-Quality Homoepitaxy of GaN: Understanding Nucleation and Design of Growth Strategies
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2022 (English)In: Crystal Growth & Design, ISSN 1528-7483, E-ISSN 1528-7505, Vol. 22, no 12, p. 7021-7030Article in journal (Refereed) Published
Abstract [en]

Thick GaN layers with a low concentration of defects are the key to enable next-generation vertical power electronic devices. Here, we explore hot-wall metalorganic chemical vapor deposition (MOCVD) for the development of GaN homoepitaxy. We propose a new approach to grow high quality homoepitaxial GaN in N2-rich carrier gas and at a higher supersaturation as compared to heteroepitaxy. We develop a low temperature GaN as an optimum nucleation scheme based on the evolution and thermal stability of the GaN surface under different gas compositions and temperatures. Analysis in the framework of nucleation theory of homoepitaxial layers simultaneously grown on GaN templates on SiC and on hydride vapor phase epitaxy GaN substrates is presented. We show that residual strain and screw dislocation densities affect GaN nucleation and subsequent growth leading to distinctively different morphologies of GaN homoepitaxial layers grown on GaN templates and native substrates, respectively. The established comprehensive picture provides a guidance for designing strategies for growth conditions optimization in GaN homoepitaxy. GaN with atomically flat and smooth epilayer surfaces with a root-mean-square roughness value as low as 0.049 nm and low background carbon concentration of 5.3 x 1015 cm-3 has been achieved. It is also shown that there is no generation of additional dislocations during homoepitaxial growth. Thus, our results demonstrate the potential of the hot-wall MOCVD technique to deliver high-quality GaN material for vertical power devices.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2022
National Category
Condensed Matter Physics
Identifiers
urn:nbn:se:liu:diva-190211 (URN)10.1021/acs.cgd.2c00683 (DOI)000883760600001 ()
Note

Funding Agencies|Swedish Governmental Agency for Innovation Systems (VINNOVA) [2016-05190]; Linkoping University; Chalmers University of technology; Ericsson; Epiluvac; FMV; Gotmic; Hexagem; Hitachi Energy Research; On Semiconductor; Saab; SweGaN; aUMS; Volvo Cars; Swedish Research Council VR [2016-00889]; Swedish Foundation for Strategic Research [RIF14-055, EM16-0024]; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University, Faculty Grant [2009-00971]; NanoLund

Available from: 2022-11-29 Created: 2022-11-29 Last updated: 2023-12-28Bibliographically approved
Tran, D., Delgado Carrascon, R., Muth, J. F., Paskova, T., Nawaz, M., Darakchieva, V. & Paskov, P. P. (2021). Correction: Erratum: “Phonon-boundary scattering and thermal transport in AlxGa1−xN: Effect of layer thickness” [Appl. Phys. Lett. 117, 252102 (2020)]. Applied Physics Letters, 118(18), Article ID 189901.
Open this publication in new window or tab >>Correction: Erratum: “Phonon-boundary scattering and thermal transport in AlxGa1−xN: Effect of layer thickness” [Appl. Phys. Lett. 117, 252102 (2020)]
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2021 (English)In: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 118, no 18, article id 189901Article in journal (Other academic) Published
Place, publisher, year, edition, pages
AIP Publishing, 2021
National Category
Condensed Matter Physics
Identifiers
urn:nbn:se:liu:diva-179850 (URN)10.1063/5.0054625 (DOI)000698625800013 ()2-s2.0-85105880689 (Scopus ID)
Available from: 2021-10-04 Created: 2021-10-04 Last updated: 2023-12-28Bibliographically approved
Tran, D., Delgado Carrascon, R., Muth, J. F., Paskova, T., Nawaz, M., Darakchieva, V. & Paskov, P. P. (2020). Phonon-boundary scattering and thermal transport in AlxGa1-xN: Effect of layer thickness. Applied Physics Letters, 117(25), Article ID 252102.
Open this publication in new window or tab >>Phonon-boundary scattering and thermal transport in AlxGa1-xN: Effect of layer thickness
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2020 (English)In: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 117, no 25, article id 252102Article in journal (Refereed) Published
Abstract [en]

Thermal conductivity of AlxGa1-xN layers with 0 <= x <= 0.96 and variable thicknesses is systematically studied by combined thermoreflectance measurements and a modified Callaway model. We find a reduction in the thermal conductivity of AlxGa1-xN by more than one order of magnitude compared to that of GaN, which indicates a strong effect of phonon-alloy scattering. It is shown that the short-mean free path phonons are strongly scattered, which leads to a major contribution of the long-mean free path phonons to the thermal conductivity. In thin layers, the long-mean free path phonons become efficiently scattered by the boundaries, resulting in a further decrease in the thermal conductivity. Also, an asymmetry of thermal conductivity as a function of Al content is experimentally observed and attributed to the mass difference between Ga and Al host atoms.

Place, publisher, year, edition, pages
AMER INST PHYSICS, 2020
National Category
Condensed Matter Physics
Identifiers
urn:nbn:se:liu:diva-172917 (URN)10.1063/5.0031404 (DOI)000603064200002 ()
Note

Funding Agencies|Swedish Governmental Agency for innovation systems (VINOVA) under Competence Center Program [2016-05190]; Swedish Research Council VRSwedish Research Council [2016-00889, 2017-03714]; Swedish Foundation for Strategic ResearchSwedish Foundation for Strategic Research [RIF14-055, EM16-0024]; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University, Faculty Grant SFO Mat LiU [2009-00971]; NSFNational Science Foundation (NSF) [CBET-1336464, DMR-1506159]

Available from: 2021-01-26 Created: 2021-01-26 Last updated: 2023-12-28Bibliographically approved
Paskov, P. P. & Monemar, B. (2018). Point Defects in group-III nitrides (1ed.). In: Jan Stehr, Irina Buyanova, Weimin Chen (Ed.), Defects in Advanced Electronic Materials and Novel Low Dimensional Structures: (pp. 27-61). Woodhead Publishing Limited
Open this publication in new window or tab >>Point Defects in group-III nitrides
2018 (English)In: Defects in Advanced Electronic Materials and Novel Low Dimensional Structures / [ed] Jan Stehr, Irina Buyanova, Weimin Chen, Woodhead Publishing Limited, 2018, 1, p. 27-61Chapter in book (Refereed)
Abstract [en]

Point defects in semiconductors play a fundamental role for the material properties. Dopants like impurities forming shallow donors and acceptors provide the means of controlling the electrical conductivity of the material, which is the basis of many applications in devices. Native defects like vacancies and interstitial atoms, and their combination with impurities introduce, mostly unwanted deep levels in the bandgap, and thus may serve as traps or recombination centers for the carriers. Some of these defects are introduced during the growth of the material, others by the processing steps necessary in the device production. In this chapter, we present current knowledge about point defects in the III-nitrides based on recent works, both experimental and theoretical, in the field. Materials discussed are AlN, GaN and InN and the ternary alloys between them.

Place, publisher, year, edition, pages
Woodhead Publishing Limited, 2018 Edition: 1
Series
Series in Optics and Optoelectronics
National Category
Condensed Matter Physics
Identifiers
urn:nbn:se:liu:diva-151555 (URN)10.1016/B978-0-08-102053-1.00002-8 (DOI)9780081020531 (ISBN)9780081020548 (ISBN)
Available from: 2018-09-23 Created: 2018-09-23 Last updated: 2018-09-24Bibliographically approved
Blumenschein, N., Slomski, M., Paskov, P. P., Kaess, F., Breckenridge, M., Muth, J. F. & Paskova, T. (2018). Thermal conductivity of bulk and thin film β-Ga2O3 measured by the 3ω technique. In: David J. Rogers, David C. Look, Ferechteh H. Teharani (Ed.), Oxide-based Materials and Devices IX: . Paper presented at Oxide-Based Materials and Devices IX 2018; San Francisco; United States; 28 January 2018 through 1 February 2018 (pp. 105332G-1-105332G-8). SPIE - International Society for Optical Engineering, 10533
Open this publication in new window or tab >>Thermal conductivity of bulk and thin film β-Ga2O3 measured by the 3ω technique
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2018 (English)In: Oxide-based Materials and Devices IX / [ed] David J. Rogers, David C. Look, Ferechteh H. Teharani, SPIE - International Society for Optical Engineering, 2018, Vol. 10533, p. 105332G-1-105332G-8Conference paper, Published paper (Refereed)
Place, publisher, year, edition, pages
SPIE - International Society for Optical Engineering, 2018
Series
Proceedings of SPIE - The International Society for Optical Engineering, ISSN 0277-786X
National Category
Condensed Matter Physics
Identifiers
urn:nbn:se:liu:diva-151556 (URN)10.1117/12.2288267 (DOI)000453074500028 ()9781510615519 (ISBN)
Conference
Oxide-Based Materials and Devices IX 2018; San Francisco; United States; 28 January 2018 through 1 February 2018
Note

Funding agencies:  NSF [CBET-1336464, DMR-1506159]; Swedish Energy Agency [P39897-1]; Swedish Research Council [2017-03714]

Available from: 2018-09-23 Created: 2018-09-23 Last updated: 2019-01-07
Paskov, P. P. & Monemar, B. (2017). Optical Properties of III-Nitride Semiconductors (1ed.). In: Wengang (Wayne) Bi, Haochung (Henry) Kuo, Peicheng Ku, Bo Shen (Ed.), Handbook of GaN Semiconductor Materials and Devices: (pp. 87-116). Boca Raton: CRC Press
Open this publication in new window or tab >>Optical Properties of III-Nitride Semiconductors
2017 (English)In: Handbook of GaN Semiconductor Materials and Devices / [ed] Wengang (Wayne) Bi, Haochung (Henry) Kuo, Peicheng Ku, Bo Shen, Boca Raton: CRC Press, 2017, 1, p. 87-116Chapter in book (Refereed)
Abstract [en]

The optical properties of the group-III-nitride materials are obviously of direct relevance for optoelectronic applications, but experiments measuring optical properties also give information on a range of electronic properties. There is already a wealth of data in the literature on the optical properties of III-nitrides [1–4], and here we will concentrate on some of the most recent additions to the scientific knowledge. The focus, looking at the present situation concerning technical applications of these materials, has been on GaN, InGaN, and AlGaN in recent decades. AlGaN materials are important for ultraviolet (UV) emitters and high electron mobility transistor (HEMT) structures and AlGaN optical properties have accordingly been studied over the entire Al composition range. InGaN materials (with In content <50%) have also been studied extensively, and the light-emitting diode (LED) applications based on InGaN/GaN quantum structures have already been awarded a Nobel Prize in 2014. However, the applications of InN are lagging behind. The development of growth procedures for InN and In-rich InGaN has been difficult, and their optical properties were consequently much less studied in the past.

Place, publisher, year, edition, pages
Boca Raton: CRC Press, 2017 Edition: 1
National Category
Physical Sciences
Identifiers
urn:nbn:se:liu:diva-151554 (URN)9781498747134 (ISBN)9781498747141 (ISBN)
Available from: 2018-09-23 Created: 2018-09-23 Last updated: 2018-09-28Bibliographically approved
Bartos, I., Romanyuk, O., Houdkova, J., Paskov, P., Paskova, T. & Jiricek, P. (2016). Correction: Electron band bending of polar, semipolar and non-polar GaN surfaces (vol 119, 105303, 2016). Journal of Applied Physics, 119(15), 159901
Open this publication in new window or tab >>Correction: Electron band bending of polar, semipolar and non-polar GaN surfaces (vol 119, 105303, 2016)
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2016 (English)In: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, Vol. 119, no 15, p. 159901-Article in journal (Refereed) Published
Abstract [en]

n/a

Place, publisher, year, edition, pages
AMER INST PHYSICS, 2016
National Category
Chemical Sciences
Identifiers
urn:nbn:se:liu:diva-130308 (URN)10.1063/1.4947183 (DOI)000378991800043 ()
Available from: 2016-07-31 Created: 2016-07-28 Last updated: 2017-11-28
Bartos, I., Romanyuk, O., Houdkova, J., Paskov, P., Paskova, T. & Jiricek, P. (2016). Electron band bending of polar, semipolar and non-polar GaN surfaces. Journal of Applied Physics, 119(10), 105303
Open this publication in new window or tab >>Electron band bending of polar, semipolar and non-polar GaN surfaces
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2016 (English)In: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, Vol. 119, no 10, p. 105303-Article in journal (Refereed) Published
Abstract [en]

The magnitudes of the surface band bending have been determined by X-ray photoelectron spectroscopy for polar, semipolar, and non-polar surfaces of wurtzite GaN crystals. All surfaces have been prepared from crystalline GaN samples grown by the hydride-vapour phase epitaxy and separated from sapphire substrates. The Ga 3d core level peak shifts have been used for band bending determination. Small band bending magnitudes and also relatively small difference between the band bendings of the surfaces with opposite polarity have been found. These results point to the presence of electron surface states of different amounts and types on surfaces of different polarity and confirm the important role of the electron surface states in compensation of the bound surface polarity charges in wurtzite GaN crystals. (C) 2016 AIP Publishing LLC.

Place, publisher, year, edition, pages
AMER INST PHYSICS, 2016
National Category
Chemical Sciences
Identifiers
urn:nbn:se:liu:diva-127439 (URN)10.1063/1.4943592 (DOI)000372976900029 ()
Note

Funding Agencies|Academy of Sciences of the Czech Republic [M100101201]; Czech Science Foundation (GACR) [15-01687S]; NSF [DMR-1207075, OISE-1458427]; Swedish Energy Agency [P39897-1]

Available from: 2016-04-30 Created: 2016-04-26 Last updated: 2017-11-30
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ORCID iD: ORCID iD iconorcid.org/0000-0003-2602-1523

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