Papers by Keyword: Homoepitaxial Growth

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Authors: Yuuki Ishida, Mitsuhiro Kushibe, Tetsuo Takahashi, Hajime Okumura, Sadafumi Yoshida
Authors: Tsunenobu Kimoto, Toshihiro Yamamoto, Zhi Yong Chen, Hiroshi Yano, Hiroyuki Matsunami
Authors: Hiroaki Saitoh, Tsunenobu Kimoto
Abstract: Chemical vapor deposition of 4H-SiC on (0001) substrates with various off-angles from 1o to 45o has been investigated. On large-off-angled (15o-45o) substrates, very smooth surface morphology is obtained in the wide range of C/Si ratio. The micropipe dissociation during epitaxial growth is observed on 4o-45o off-angled substrates with a low C/Si ratio. The incorporation of nitrogen was dramatically suppressed by increasing C/Si ratio irrespective of substrate’s off-angle.
Authors: Y. Kawai, Tomohiko Maeda, Yoshihiro Nakamura, Yoji Sakurai, Motoaki Iwaya, Satoshi Kamiyama, Hiroshi Amano, Isamu Akasaki, Masahiro Yoshimoto, Tomoaki Furusho, Hiroyuki Kinoshita, Hiromu Shiomi
Abstract: We demonstrate high-speed and high-quality 6H-SiC homoepitaxial growth on a 1°-off c-plane SiC substrate by a closed-space sublimation method. By optimizing the size of single-crystal source materials in the growth system, a high-quality 6H-SiC epilayer with an X-ray diffraction rocking curve (0006) full-width at the half maximum (FWHM) of 38 arcsec was obtained. We also carried out doping of nitrogen and boron during the growth of the SiC epilayer. A strong donor-acceptor pair (DAP) emission at a peak wavelength of 570 nm under excitation by a 395 nm nitride-based light-emitting diode (LED) was observed. The 6H-SiC with DAP emission is promising for use as a phosphor in a nitride-based LED, because high-quality nitride layers can be grown on the SiC substrates with small off-oriented angles.
Authors: Stefano Leone, Henrik Pedersen, Franziska Christine Beyer, Sven Andersson, Olof Kordina, Anne Henry, Andrea Canino, Francesco La Via, Erik Janzén
Abstract: A review of recently achieved results with the chloride-based CVD on 8° and 4° off axis and nominally on-axis 4H-SiC wafers is done to clarify the epitaxial growth mechanisms on different off-angle substrates. The process conditions selected for each off-axis angle become even more difficult when running at growth rates of 100 µm/h or more. A fine-tuning of process parameters mainly temperature, C/Si ratio and in situ surface preparation is necessary for each off-angle. Some trends related to the surface properties and the effective C/Si ratio existing on the surface prior to and during the epitaxial growth can be observed.
Authors: Yuuki Ishida, Tetsuo Takahashi, Hajime Okumura, Kazuo Arai, Sadafumi Yoshida
Abstract: We have developed a new chemical vapor deposition (CVD) system that is capable of a high growth rate of over 100 µm/h with good uniformities of thickness and carrier concentration. In this CVD system, the process gases contribute efficiently to epitaxial growth. In a demonstration of the abilities of the CVD system, we achieved an average growth rate of 140 µm/h, a thickness uniformity of 3.9%, and a carrier concentration uniformity of 8.9% in a 2-inch wafer, without degradation of the crystallinity.
Authors: Kazutoshi Kojima, Satoshi Kuroda, Hajime Okumura, Kazuo Arai
Abstract: We have investigated the influence of in-situ H2 etching on the surface morphology of the 4H-SiC substrate prior to homoepitaxial growth. In this study, we varied the types of gas atmosphere during in-situ H2 etching; namely, hydrogen (H2) alone, hydrogen-propane (H2+C3H8), and hydrogen-silane (H2+SiH4). We found that in-situ H2 etching using H2 + SiH4 significantly improved the surface morphology of 4H-SiC substrate just after in-situ H2 etching. By adding SiH4, formation of bunched step structure during in-situ H2 etching could be significantly suppressed. In addition, H2 etching using H2 + SiH4 was able to remove scratches by etching a thinner layer than that using H2 alone. We also discussed the in-situ H2 etching mechanism under the additional SiH4 condition.
Authors: Kazutoshi Kojima, Takaya Ohno, Junji Senzaki, Kenji Fukuda, Tatsuo Fujimoto, Masakazu Katsuno, Noboru Ohtani, Johji Nishio, Koh Masahara, Yuuki Ishida, Tetsuo Takahashi, Takaya Suzuki, Tomoyuki Tanaka, Sadafumi Yoshida, Kazuo Arai
Authors: Francesco La Via, G. Galvagno, A. Firrincieli, Fabrizio Roccaforte, Salvatore di Franco, Alfonso Ruggiero, Milo Barbera, Ricardo Reitano, Paolo Musumeci, Lucia Calcagno, Gaetano Foti, Marco Mauceri, Stefano Leone, Giuseppe Pistone, F. Portuese, Giuseppe Abbondanza, Giovanni Abagnale, Gian Luca Valente, Danilo Crippa
Abstract: The growth rate of 4H-SiC epi layers has been increased by a factor 3 (up to 18μm/h) with respect to the standard process with the introduction of HCl in the deposition chamber. The epitaxial layers grown with the addition of HCl have been characterized by electrical, optical and structural characterization methods. An optimized process without the addition of HCl is reported for comparison. The Schottky diodes, manufactured on the epitaxial layer grown with the addition of HCl at 1600 °C, have electrical characteristics comparable with the standard epitaxial process with the advantage of an epitaxial growth rate three times higher.
Authors: Andrew J. Trunek, Philip G. Neudeck, David J. Spry
Abstract: We report on further observations of homoepitaxially grown 4H silicon carbide (SiC) cantilevers on commercial on-axis mesa patterned substrates. Mesa shapes with hollow interiors were designed to significantly increase the ratio of dislocation-free cantilever area to pregrowth mesa area. Mesas that did not contain axial screw dislocations (SD’s) continued to expand laterally until uncontrolled growth in the trench regions rises up to interfere / merge with the laterally expanding cantilevers. Molten KOH etching revealed high defect density in regions where trench growth merged with the laterally expanding cantilevers. The remaining portions of the cantilevers, except for central coalescence points, remained free of dislocations.
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