Papers by Author: Isaho Kamata

Paper TitlePage

Authors: Hidekazu Tsuchida, Isaho Kamata, Tamotsu Jikimoto, Toshiyuki Miyanagi, Kunikaza Izumi
Authors: Koji Nakayama, Yoshitaka Sugawara, Hidekazu Tsuchida, Toshiyuki Miyanagi, Isaho Kamata, Tomonori Nakamura, Katsunori Asano, R. Ishii
Abstract: The dependence of forward voltage degradation on crystal faces for 4H-SiC pin diodes has been investigated. The forward voltage degradation has been reduced by fabricating the diodes on the (000-1) C-face off-angled toward <11-20>. High-voltage 4H-SiC pin diodes on the (000-1) C-face with small forward voltage degradation have also been fabricated successfully. A high breakdown voltage of 4.6 kV and DVf of 0.04 V were achieved for a (000-1) C-face pin diode. A 8.3 kV blocking performance, which is the highest voltage in the use of (000-1) C-face, is also demonstrated in 4H-SiC pin diode.
Authors: Isaho Kamata, Hidekazu Tsuchida, Tamotsu Jikimoto, Kunikaza Izumi
Authors: Takashi Tsuji, Syunsuke Izumi, A. Ueda, Hiroyuki Fujisawa, Katsunori Ueno, Hidekazu Tsuchida, Isaho Kamata, Tamotsu Jikimoto, Kunikaza Izumi
Authors: Syunsuke Izumi, Isaho Kamata, Takeshi Tawara, Hiroyuki Fujisawa, Hidekazu Tsuchida
Authors: Hidekazu Tsuchida, Takashi Tsuji, Isaho Kamata, Tamotsu Jikimoto, Hiroyuki Fujisawa, Shinji Ogino, Kunikaza Izumi
Authors: Isaho Kamata, Masahiro Nagano, Hidekazu Tsuchida
Abstract: Burgers vector directions of threading edge dislocations (TEDs) in 4H-SiC epitaxial layer are distinguished by grazing incidence high resolution topography. Based on comparison between appearance of KOH etch pits and direction of TED Burgers vector, the size difference of the TED etch pits is found to be dependent on their Burgers vector directions. Examining TEDs in the epilayer by topography, the Burgers vector direction of basal plane dislocations (BPDs) in the substrate is identified. Correspondence between the topography contrast and the sense of a BPD is also investigated.
Authors: Tetsuo Takahashi, Yuuki Ishida, Hidekazu Tsuchida, Isaho Kamata, Hajime Okumura, Sadafumi Yoshida, Kazuo Arai
Authors: Tomonori Nakamura, Toshiyuki Miyanagi, Isaho Kamata, Hidekazu Tsuchida
Abstract: We compared the electrical characteristics of 4H-SiC(0001) and (000-1) Schottky barrier diodes (SBDs), and derived the Schottky barrier heights (Hbs) of Ta, W, Mo, and Pd on {0001}. We investigated the annealing temperature dependence of Hbs in Mo and the W Schottky contacts for (0001) and (000-1). The Hbs are increased by annealing, except for the W Schottky contact on (0001). The yields of 0.25 cm2 as-deposited Mo-SBDs were 93.3% for (0001) and 71.1% for (000-1), respectively. We also demonstrated over 1 cm2 (0001) as-deposited Mo-SBD with a low leakage current, an excellent ideality factor, and no excess current, encouraging the enlargement of the active area in the SBD.
Authors: Hidekazu Tsuchida, Isaho Kamata, Toshiyuki Miyanagi, Tomonori Nakamura, Koji Nakayama, R. Ishii, Yoshitaka Sugawara
Abstract: Propagation and nucleation of basal plane dislocations (BPDs) in 4H-SiC(000-1) and (0001) epitaxy were compared. Synchrotron reflection X-ray topography was performed before and after epitaxial growth to classify the BPDs into those propagated from the substrate into the epilayer and those nucleated in the epilayer. It was revealed that the propagation ratio of BPDs for the (000-1) epitaxy was significantly smaller than that for the (0001) epitaxy. Growing (000-1) epilayers at a high C/Si ratio of 1.2 achieves a further reduction in BPDs to only 3 cm-2 for those propagated from the substrate, and 16 cm-2 for those nucleated in the epilayer. A dramatic increase was also found in the nucleation of BPDs omitting the re-polishing and in-situ H2 etching procedure.
Showing 1 to 10 of 44 Paper Titles