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3 pages, 157 KiB

Open AccessEditorial

Development and Investigation of SiC and SiC-Based Devices

by Alexander A. Lebedev

Crystals 2020, 10(12), 1127; https://doi.org/10.3390/cryst10121127 - 11 Dec 2020

Cited by 1 | Viewed by 1638

Abstract

The modern development of the nuclear industry, nuclear energy, and aerospace technology is in dire need of the development of a new generation of electronics capable of operating at elevated levels of radiation and high temperatures and in chemically active environments [...] Full article

(This article belongs to the Special Issue Development and Investigation of SiC and SiC-based devices)

Research

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11 pages, 1226 KiB

Open AccessArticle

Influence of Carbon Cap on Self-Diffusion in Silicon Carbide

by Marianne Etzelmüller Bathen, Margareta Linnarsson, Misagh Ghezellou, Jawad Ul Hassan and Lasse Vines

Crystals 2020, 10(9), 752; https://doi.org/10.3390/cryst10090752 - 26 Aug 2020

Cited by 5 | Viewed by 5243

Abstract

Self-diffusion of carbon (

^{12}

C and

^{13}

C) and silicon (

^{28}

Si and

^{30}

Si) in 4H silicon carbide has been investigated by utilizing a structure containing an isotope purified 4H-

^{28}

Si

^{12}

C epitaxial layer grown on an n-type [...] Read more.

Self-diffusion of carbon (

^{12}

C and

^{13}

C) and silicon (

^{28}

Si and

^{30}

Si) in 4H silicon carbide has been investigated by utilizing a structure containing an isotope purified 4H-

^{28}

Si

^{12}

C epitaxial layer grown on an n-type (0001) 4H-SiC substrate, and finally covered by a carbon capping layer (C-cap). The

^{13}

C and

^{30}

Si isotope profiles were monitored using secondary ion mass spectrometry (SIMS) following successive heat treatments performed at

2300 - 2450^{\circ} C

in Ar atmosphere using an inductively heated furnace. The

^{30}

Si profiles show little redistribution within the studied temperature range, with the extracted diffusion lengths for Si being within the error bar for surface roughening during annealing, as determined by profilometer measurements. On the other hand, a significant diffusion of

^{13}

C was observed into the isotope purified layer from both the substrate and the C-cap. A diffusivity of

D = 8.3 \times 10^{6} e^{- 10.4 / k_{B} T}

cm

^{2}

/s for

^{13}

C was extracted, in contrast to previous findings that yielded lower both pre-factors and activation energies for C self-diffusion in SiC. The discrepancy between the present measurements and previous theoretical and experimental works is ascribed to the presence of the C-cap, which is responsible for continuous injection of C interstitials during annealing, and thereby suppressing the vacancy mediated diffusion. Full article

(This article belongs to the Special Issue Development and Investigation of SiC and SiC-based devices)

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12 pages, 982 KiB

Open AccessArticle

Investigation of Barrier Inhomogeneities and Electronic Transport on Al-Foil/p-Type-4H-SiC Schottky Barrier Diodes Using Diffusion Welding

by Mehadi Hasan Ziko, Ants Koel, Toomas Rang and Muhammad Haroon Rashid

Crystals 2020, 10(8), 636; https://doi.org/10.3390/cryst10080636 - 23 Jul 2020

Cited by 6 | Viewed by 3048

Abstract

The diffusion welding (DW) is a comprehensive mechanism that can be extensively used to develop silicon carbide (SiC) Schottky rectifiers as a cheaper alternative to existing mainstream contact forming technologies. In this work, the Schottky barrier diode (SBD) fabricated by depositing Al-Foil on [...] Read more.

The diffusion welding (DW) is a comprehensive mechanism that can be extensively used to develop silicon carbide (SiC) Schottky rectifiers as a cheaper alternative to existing mainstream contact forming technologies. In this work, the Schottky barrier diode (SBD) fabricated by depositing Al-Foil on the p-type 4H-SiC substrate with a novel technology; DW. The electrical properties of physically fabricated Al-Foil/4H-SiC SBD have been investigated. The current-voltage (I-V) and capacitance-voltage (C-V) characteristics based on the thermionic emission model in the temperature range (300 K–450 K) are investigated. It has been found that the ideality factor and barrier heights of identically manufactured Al-Foil/p-type-4H-SiC SBDs showing distinct deviation in their electrical characteristics. An improvement in the ideality factor of Al-Foil/p-type-4H-SiC SBD has been noticed with an increase in temperature. An increase in barrier height in fabricated SBD is also observed with an increase in temperature. We also found that these increases in barrier height, improve ideality factors and abnormalities in their electrical characteristics are due to structural defects initiation, discrete energy level formation, interfacial native oxide layer formation, inhomogenous doping profile distribution and tunneling current formation at the SiC sufaces. Full article

(This article belongs to the Special Issue Development and Investigation of SiC and SiC-based devices)

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13 pages, 7668 KiB

Open AccessArticle

Thick β-SiC CVD-Coated SiC Die System for Dry Cold Forging of Metals

by Tatsuhiko Aizawa, Tomoaki Yoshino, Ko-Ichi Ito and Tatsuya Fukuda

Crystals 2020, 10(6), 539; https://doi.org/10.3390/cryst10060539 - 24 Jun 2020

Cited by 11 | Viewed by 3404

Abstract

A thick β-SiC CVD (chemical vapor deposition)-coated SiC device was developed as a new punch and die system for dry, cold forging of pure titanium and austenitic stainless-steel works. This β-SiC coating thickness was 4 mm, enough to make mechanical machining of a [...] Read more.

A thick β-SiC CVD (chemical vapor deposition)-coated SiC device was developed as a new punch and die system for dry, cold forging of pure titanium and austenitic stainless-steel works. This β-SiC coating thickness was 4 mm, enough to make mechanical machining of a cavity into β-SiC coating core die. These β-SiC-coated punch and core dies were fixed into the cassette die for dry, cold forging experiments. The stainless steel and titanium wires with diameters of 1.0 mm were employed as the work material. Different from the conventional metallic and ceramic die systems suffering from work material transfer, this system sustained the galling-free cold, dry forging behavior up to a higher reduction of thickness than 30%. The power to stroke the relationship was in situ monitored to describe this forging behavior up to the specified reduction of the wires together with observations on the geometric change from a circular wire to a pentagonal prism bar. Precise scanning electron microscopy-electron-dispersive X-ray spectroscopy (SEM-EDX) analyses were performed to describe the material compatibility on the contact interface between β-SiC coating and elastoplastically deforming works. Full article

(This article belongs to the Special Issue Development and Investigation of SiC and SiC-based devices)

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21 pages, 2747 KiB

Open AccessArticle

Imprinting the Polytype Structure of Silicon Carbide by Rapid Thermal Processing

by Jörg Pezoldt and Volker Cimalla

Crystals 2020, 10(6), 523; https://doi.org/10.3390/cryst10060523 - 18 Jun 2020

Cited by 6 | Viewed by 4155

Abstract

Silicon carbide is a material with a multistable crystallographic structure, i.e., a polytypic material. Different polytypes exhibit different band gaps and electronic properties with nearly identical basal plane lattice constants, making them interesting for heterostructures without concentration gradients. The controlled formation of this [...] Read more.

Silicon carbide is a material with a multistable crystallographic structure, i.e., a polytypic material. Different polytypes exhibit different band gaps and electronic properties with nearly identical basal plane lattice constants, making them interesting for heterostructures without concentration gradients. The controlled formation of this heterostructure is still a challenge. The ability to adjust a defined temperature–time profile using rapid thermal processing was used to imprint the polytype transitions by controlling the nucleation and structural evolution during the temperature ramp-up and the steady state. The influence of the linear heating-up rate velocity during ramp-up and steady-state temperature on the crystal structure of amorphized ion-implanted silicon carbide layers was studied and used to form heteropolytype structures. Integrating the structural selection properties of the non-isothermal annealing stage of the ion-implanted layers into an epitaxial growth process allows the imprinting of polytype patterns in epitaxial layers due to the structural replication of the polytype pattern during epitaxial growth. The developed methodology paves the way for structural selection and vertical and lateral polytype patterning. In rapid thermal chemical vapor deposition, the adjustment of the process parameters or the buffer layer allowed the nucleation and growth of wurtzite silicon carbide. Full article

(This article belongs to the Special Issue Development and Investigation of SiC and SiC-based devices)

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15 pages, 2861 KiB

Open AccessArticle

Low Temperature Growth of the Nanotextured Island and Solid 3C-SiC Layers on Si from Hydric Si, Ge and C Compounds

by Lev K. Orlov, Vladimir I. Vdovin, Natalia L. Ivina, Eduard A. Steinman, Yurii N. Drozdov and Michail L. Orlov

Crystals 2020, 10(6), 491; https://doi.org/10.3390/cryst10060491 - 7 Jun 2020

Cited by 2 | Viewed by 2477

Abstract

Different growth stages and surface morphology of the epitaxial 3C-SiC/Si(100) structures were studied. Heterocompositions were grown in vacuum from hydric compounds at a lower temperature. The composition, surface morphology and crystal structure of the 3C-SiC films were tested using X-ray diffraction, second ion [...] Read more.

Different growth stages and surface morphology of the epitaxial 3C-SiC/Si(100) structures were studied. Heterocompositions were grown in vacuum from hydric compounds at a lower temperature. The composition, surface morphology and crystal structure of the 3C-SiC films were tested using X-ray diffraction, second ion mass spectrometry, scanning ion and electron microscopy, photo- and cathode luminescence. It was demonstrated that the fine crystal structure of the 3C-SiC islands was formed by the close-packed nanometer-size grains and precipitated on the underlying solid carbonized Si layer. Luminescence spectral lines of the solid carbonized Si layer, separated island and solid textured 3C-SiC layer were shifted toward the high ultraviolet range. The spectra measured by different methods were compared and the nature of the revealed lines was considered. This article discusses a quantum confinement effect observation in the 3C-SiC nanostructures and a perspective for the use of nanotextured island 3C-SiC layers as a two-dimensional surface quantum superlattice for high-frequency applications. The conductivity anisotropy and current-voltage characteristics of the two-dimensional superlattices with a non-additive electron dispersion law in the presence of a strong electric field were studied theoretically. Main efforts were focused on a search of the mechanisms allowing realization of the high-frequency negative dynamical conductivity for the structures having a positive static differential conductivity. Full article

(This article belongs to the Special Issue Development and Investigation of SiC and SiC-based devices)

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9 pages, 2146 KiB

Open AccessArticle

Exploring SiC Planar IGBTs towards Enhanced Conductivity Modulation Comparable to SiC Trench IGBTs

by Meng Zhang, Baikui Li and Jin Wei

Crystals 2020, 10(5), 417; https://doi.org/10.3390/cryst10050417 - 23 May 2020

Cited by 4 | Viewed by 4099

Abstract

The state-of-the-art silicon insulated-gate bipolar transistor (IGBT) features a trench gate, since it enhances the conductivity modulation. The SiC trench IGBT, however, faces the critical challenge of a high electric field in the gate oxide, which is a crucial threat to the device’s [...] Read more.

The state-of-the-art silicon insulated-gate bipolar transistor (IGBT) features a trench gate, since it enhances the conductivity modulation. The SiC trench IGBT, however, faces the critical challenge of a high electric field in the gate oxide, which is a crucial threat to the device’s reliability. In this work, we explore the possibility of using a SiC planar IGBT structure to approach high performance to the level of a SiC trench IGBT, without suffering the high gate oxide field. The proposed SiC planar IGBT features buried p-layers directly under the p-bodies, and thus can be formed using the same mask set. The region between the buried p-layer and the p-body is heavily doped with n-type dopants so that the conductivity modulation is improved. Comprehensive TCAD simulations have been carried out to verify this concept, and the simulation results show the new SiC planar IGBT exhibits a high performance comparable to the trench IGBT, and also exhibits a low gate oxide field. Full article

(This article belongs to the Special Issue Development and Investigation of SiC and SiC-based devices)

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7 pages, 1630 KiB

Open AccessArticle

Minority Carrier Trap in n-Type 4H–SiC Schottky Barrier Diodes

by Ivana Capan, Yuichi Yamazaki, Yuya Oki, Tomislav Brodar, Takahiro Makino and Takeshi Ohshima

Crystals 2019, 9(7), 328; https://doi.org/10.3390/cryst9070328 - 27 Jun 2019

Cited by 11 | Viewed by 3942

Abstract

We present preliminary results on minority carrier traps in as-grown n-type 4H–SiC Schottky barrier diodes. The minority carrier traps are crucial for charge trapping and recombination processes. In this study, minority carrier traps were investigated by means of minority carrier transient spectroscopy [...] Read more.

We present preliminary results on minority carrier traps in as-grown n-type 4H–SiC Schottky barrier diodes. The minority carrier traps are crucial for charge trapping and recombination processes. In this study, minority carrier traps were investigated by means of minority carrier transient spectroscopy (MCTS) and high-resolution Laplace-MCTS measurements. A single minority carrier trap with its energy level position at E_v + 0.28 eV was detected and assigned to boron-related defects. Full article

(This article belongs to the Special Issue Development and Investigation of SiC and SiC-based devices)

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6 pages, 1261 KiB

Open AccessArticle

Radiation Defects in Heterostructures 3C-SiC/4H-SiC

by A.A. Lebedev, G.A. Oganesyan, V.V. Kozlovski, I.A. Eliseyev and P.V. Bulat

Crystals 2019, 9(2), 115; https://doi.org/10.3390/cryst9020115 - 22 Feb 2019

Cited by 14 | Viewed by 6189

Abstract

The effect of 8 MeV proton irradiation on n-3C-SiC epitaxial layers grown by sublimation on semi-insulating 4H-SiC substrates has been studied. Changes in sample parameters were recorded using the Hall-effect method and judged from photoluminescence spectra. It was found [...] Read more.

The effect of 8 MeV proton irradiation on n-3C-SiC epitaxial layers grown by sublimation on semi-insulating 4H-SiC substrates has been studied. Changes in sample parameters were recorded using the Hall-effect method and judged from photoluminescence spectra. It was found that the carrier removal rate (Vd) in 3C-SiC is ~100 cm⁻¹, which is close to Vd in 4H-SiC. Compared with 4H and 6H silicon carbide, no significant increase in the intensity of the so-called defect-related photoluminescence was observed. An assumption is made that radiation-induced compensation processes in 3C-SiC are affected by structural defects (twin boundaries), which are always present in epitaxial cubic silicon carbide layers grown on substrates of the hexagonal polytypes. Full article

(This article belongs to the Special Issue Development and Investigation of SiC and SiC-based devices)

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