Shockley

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Tsunenobu Kimoto - One of the best experts on this subject based on the ideXlab platform.

  • correlation between shapes of Shockley stacking faults and structures of basal plane dislocations in 4h sic epilayers
    Philosophical Magazine, 2017
    Co-Authors: Akifumi Iijima, Jun Suda, Isaho Kamata, Hidekazu Tsuchida, Tsunenobu Kimoto
    Abstract:

    Shockley-type stacking faults expanded in 4H–SiC epilayers induced by ultraviolet illumination were investigated using a photoluminescence imaging method, a photoluminescence mapping method and X-r...

  • observation of double Shockley stacking fault expansion in heavily nitrogen doped 4h sic using pl technique
    Journal of Crystal Growth, 2017
    Co-Authors: Tsunenobu Kimoto, Isaho Kamata, Yuichiro Tokuda, N Hoshino, Tomohisa Kato, Hajime Okumura, Hidekazu Tsuchida
    Abstract:

    Abstract The expansion of double-Shockley stacking faults (DSFs) in 4H-SiC was investigated by a photoluminescence (PL) imaging technique. To observe DSFs nondestructively, heavily-nitrogen-doped epilayers were prepared to be used as specimens and the PL technique was applied for the observation. The size and shape of the DSFs in the epilayer were clearly distinguished in the two dimensional PL images, although it is normally difficult to observe luminescence from DSFs in substrates grown by the sublimation method. The nucleation and expansion of the DSFs were tracked in the course of successive high-temperature annealing. Dislocation velocities of Shockley partials along the edge of the DSFs were evaluated from the PL observations. Activation energy for the dislocation glide was estimated from the temperature dependence of the velocities. The nucleation sites of the DSFs are also discussed.

  • characterization of major in grown stacking faults in 4h sic epilayers
    Physica B-condensed Matter, 2009
    Co-Authors: Gan Feng, Jun Suda, Tsunenobu Kimoto
    Abstract:

    The optical properties of major in-grown stacking faults (IGSFs) in 4H-SiC epilayers have been characterized by micro-photoluminescence (micro-PL) spectroscopy and its intensity mapping. Strong PL emissions from the IGSFs are observed even at room temperature. Three kinds of IGSFs have been identified in the samples based on the micro-PL spectra. Each kind of IGSF shows the distinct PL emission peak located at 460, 480, and 500 nm, respectively. The micro-PL intensity mapping at the emission band of each IGSF has been performed to spatially profile the IGSF. The shapes, distributions, and densities of IGSFs in the epilayers are then presented. The microstructure of each IGSF has been revealed by high-resolution transmission electron microscopy observations. The stacking sequences of three IGSFs are determined as (4,4), (3,5), and (6,0) in the Zhdanov's notation, respectively, which apparently differ from the perfect 4H-SiC, (2,2). Three identified IGSFs are then classified as quadruple Shockley SFs, triple Shockley SFs, and double Shockley SFs, respectively, based on the shear formation model.

  • triple Shockley type stacking faults in 4h sic epilayers
    Applied Physics Letters, 2009
    Co-Authors: Gan Feng, Jun Suda, Tsunenobu Kimoto
    Abstract:

    4H-SiC epilayers have been characterized by microphotoluminescence (micro-PL) spectroscopy and micro-PL intensity mapping at room temperature. A type of stacking fault (SF) with a peak emission wavelength at 480 nm (2.58 eV) has been identified. The shape of this SF is triangular revealed by the micro-PL intensity mapping. Conventional and high-resolution transmission electron microscopies have been carried out to investigate the structure of this SF. Its stacking sequence is determined as (3,5) in Zhdanov’s notation, which is consistent with that of the triple Shockley SF. The formation mechanism of this SF is also discussed.

Masaaki Miyajima - One of the best experts on this subject based on the ideXlab platform.

  • injected carrier concentration dependence of the expansion of single Shockley type stacking faults in 4h sic pin diodes
    Journal of Applied Physics, 2018
    Co-Authors: Takeshi Tawara, Shinichiro Matsunaga, Takumi Fujimoto, Mina Ryo, Masaki Miyazato, Tetsuya Miyazawa, Kensuke Takenaka, Masaaki Miyajima, Akihiro Otsuki, Yoshiyuki Yonezawa
    Abstract:

    We investigated the relationship between the dislocation velocity and the injected carrier concentration on the expansion of single Shockley-type stacking faults by monitoring the electroluminescence from 4H-SiC PiN diodes with various anode Al concentrations. The injected carrier concentration was calculated using a device simulation that took into account the measured accumulated charge in the drift layer during diode turn-off. The dislocation velocity was strongly dependent on the injected hole concentration, which represents the excess carrier concentration. The activation energy of the dislocation velocity was quite small (below 0.001 eV between 310 and 386 K) over a fixed range of hole concentrations. The average threshold hole concentration required for the expansion of bar-shaped single Shockley-type stacking faults at the interface between the buffer layer and the substrate was determined to be 1.6–2.5 × 1016 cm−3 for diodes with a p-type epitaxial anode with various Al concentrations.

  • growth of Shockley type stacking faults upon forward degradation in 4h sic p i n diodes
    Journal of Applied Physics, 2016
    Co-Authors: Atsushi Tanaka, Hirofumi Matsuhata, Takeshi Tawara, Takumi Fujimoto, Mina Ryo, Masaki Miyazato, Naoyuki Kawabata, Daisuke Mori, Kei Inoue, Masaaki Miyajima
    Abstract:

    The growth of Shockley type stacking faults in p-i-n diodes fabricated on the C-face of 4H-SiC during forward current operation was investigated using Berg-Barrett X-ray topography and photoluminescence imaging. After forward current experiment, Shockley type stacking faults were generated from very short portions of basal plane dislocations lower than the conversion points to threading edge dislocations in the epitaxial layer. The growth behavior of Shockley type stacking faults was discussed. Growth of stacking faults in the substrates was not observed.

Takeshi Tawara - One of the best experts on this subject based on the ideXlab platform.

  • injected carrier concentration dependence of the expansion of single Shockley type stacking faults in 4h sic pin diodes
    Journal of Applied Physics, 2018
    Co-Authors: Takeshi Tawara, Shinichiro Matsunaga, Takumi Fujimoto, Mina Ryo, Masaki Miyazato, Tetsuya Miyazawa, Kensuke Takenaka, Masaaki Miyajima, Akihiro Otsuki, Yoshiyuki Yonezawa
    Abstract:

    We investigated the relationship between the dislocation velocity and the injected carrier concentration on the expansion of single Shockley-type stacking faults by monitoring the electroluminescence from 4H-SiC PiN diodes with various anode Al concentrations. The injected carrier concentration was calculated using a device simulation that took into account the measured accumulated charge in the drift layer during diode turn-off. The dislocation velocity was strongly dependent on the injected hole concentration, which represents the excess carrier concentration. The activation energy of the dislocation velocity was quite small (below 0.001 eV between 310 and 386 K) over a fixed range of hole concentrations. The average threshold hole concentration required for the expansion of bar-shaped single Shockley-type stacking faults at the interface between the buffer layer and the substrate was determined to be 1.6–2.5 × 1016 cm−3 for diodes with a p-type epitaxial anode with various Al concentrations.

  • growth of Shockley type stacking faults upon forward degradation in 4h sic p i n diodes
    Journal of Applied Physics, 2016
    Co-Authors: Atsushi Tanaka, Hirofumi Matsuhata, Takeshi Tawara, Takumi Fujimoto, Mina Ryo, Masaki Miyazato, Naoyuki Kawabata, Daisuke Mori, Kei Inoue, Masaaki Miyajima
    Abstract:

    The growth of Shockley type stacking faults in p-i-n diodes fabricated on the C-face of 4H-SiC during forward current operation was investigated using Berg-Barrett X-ray topography and photoluminescence imaging. After forward current experiment, Shockley type stacking faults were generated from very short portions of basal plane dislocations lower than the conversion points to threading edge dislocations in the epitaxial layer. The growth behavior of Shockley type stacking faults was discussed. Growth of stacking faults in the substrates was not observed.

Louis K. Mansur - One of the best experts on this subject based on the ideXlab platform.

  • on the origin of deformation microstructures in austenitic stainless steel part i microstructures
    Acta Materialia, 2001
    Co-Authors: E H Lee, Thak Sang Byun, John D. Hunn, M. H. Yoo, K. Farrell, Louis K. Mansur
    Abstract:

    Abstract A comprehensive characterization of room temperature deformation microstructures was carried out by transmission electron microscopy for ion irradiated and deformed AISI 316LN austenitic stainless steel. Deformation microstructures were produced by a recently developed disk-bend test method and also by a uniaxial tensile test. Cross-slip was dramatically suppressed by the radiation-induced defects and slip occurred predominantly by planar glide of Shockley partial dislocations. Deformed microstructures consisted of piled-up dislocations, nanotwin layers, stacking faults, and defect-reduced dislocation channel bands. Analyses revealed that all these features were different manifestations of the same type of deformation band, namely a composite of overlapping faulted layers produced by Shockley partial dislocations.

  • On the origin of deformation microstructures in austenitic stainless steel: Part II—Mechanisms
    Acta Materialia, 2001
    Co-Authors: E H Lee, Thak Sang Byun, John D. Hunn, M. H. Yoo, K. Farrell, Louis K. Mansur
    Abstract:

    Abstract Deformation microstructures of austenitic stainless steels consist of profuse pile-up dislocations, stacking faults, nanotwins, and defect-reduced channels as demonstrated in the Part I companion paper of this title [ Acta mater. , 2001, 49 (16), 3269–3276]. Yet the mechanisms of such microstructural evolution are poorly understood. Thus, a comprehensive study was conducted to understand the underlying physics of deformation in metals using radiation damage as a tool. It was found that, for energetic reasons, glide dislocations dissociated into Shockley partials during glide. Consequently, the interaction between a glide dislocation and radiation-induced defects occurs by a two-step reaction, first with the leading partial and then with the trailing partial. With this insight, the origin of deformation microstructures was explained by analyzing Shockley partial dislocations and their interactions with radiation-induced Frank loops.

Masaki Miyazato - One of the best experts on this subject based on the ideXlab platform.

  • injected carrier concentration dependence of the expansion of single Shockley type stacking faults in 4h sic pin diodes
    Journal of Applied Physics, 2018
    Co-Authors: Takeshi Tawara, Shinichiro Matsunaga, Takumi Fujimoto, Mina Ryo, Masaki Miyazato, Tetsuya Miyazawa, Kensuke Takenaka, Masaaki Miyajima, Akihiro Otsuki, Yoshiyuki Yonezawa
    Abstract:

    We investigated the relationship between the dislocation velocity and the injected carrier concentration on the expansion of single Shockley-type stacking faults by monitoring the electroluminescence from 4H-SiC PiN diodes with various anode Al concentrations. The injected carrier concentration was calculated using a device simulation that took into account the measured accumulated charge in the drift layer during diode turn-off. The dislocation velocity was strongly dependent on the injected hole concentration, which represents the excess carrier concentration. The activation energy of the dislocation velocity was quite small (below 0.001 eV between 310 and 386 K) over a fixed range of hole concentrations. The average threshold hole concentration required for the expansion of bar-shaped single Shockley-type stacking faults at the interface between the buffer layer and the substrate was determined to be 1.6–2.5 × 1016 cm−3 for diodes with a p-type epitaxial anode with various Al concentrations.

  • growth of Shockley type stacking faults upon forward degradation in 4h sic p i n diodes
    Journal of Applied Physics, 2016
    Co-Authors: Atsushi Tanaka, Hirofumi Matsuhata, Takeshi Tawara, Takumi Fujimoto, Mina Ryo, Masaki Miyazato, Naoyuki Kawabata, Daisuke Mori, Kei Inoue, Masaaki Miyajima
    Abstract:

    The growth of Shockley type stacking faults in p-i-n diodes fabricated on the C-face of 4H-SiC during forward current operation was investigated using Berg-Barrett X-ray topography and photoluminescence imaging. After forward current experiment, Shockley type stacking faults were generated from very short portions of basal plane dislocations lower than the conversion points to threading edge dislocations in the epitaxial layer. The growth behavior of Shockley type stacking faults was discussed. Growth of stacking faults in the substrates was not observed.