Silicon Carbide and Related Materials 2004

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Authors: Motoi Nakao, Hirofumi Iikawa, Katsutoshi Izumi, Takashi Yokoyama, Sumio Kobayashi
Abstract: 200 mm wafer with 3C-SiC/SiO2/Si structure has been fabricated using 200 mm siliconon- insulator (SOI) wafer. A top Si layer of 200 mm SOI wafer was thinned down to approximately 5 nm by sacrificial oxidization, and the ultrathin top Si layer was metamorphosed into a 3C-SiC seed layer using a carbonization process. Afterward, an epitaxial SiC layer was grown on the SiC seed layer with ultra-high vacuum chemical vapor deposition. A cross-section transmission electron microscope indicated that a 3C-SiC seed layer was formed directly on the buried oxide layer of 200 mm wafer. The epitaxial SiC layer with an average thickness of approximately 100 nm on the seed was recognized over the entire region of the wafer, although thickness uniformity of the epitaxial SiC layer was not as good as that of SiC seed layer. A transmission electron diffraction image of the epitaxial SiC layer showed a monocrystalline 3C-SiC(100) layer with good crystallinity. These results indicate that our method enables to realize 200 mm SiC wafers.
Authors: Hideki Shimizu, Kensaku Hisada, Yosuke Aoyama
Abstract: Effects of the flow rate of C3H8 passed through hydrogen plasma on deposition rates and^microstructures of 3C-SiC films on Si (100) substrate were investigated by a reflection electron diffraction, an X-ray diffraction and an ellipsometric measurement. The deposition rate of the films increased independently of the flow rate of C3H8 with increasing the flow rate of SiH4. The films grown with increasing the flow rate of C3H8 kept single crystalline structure even at high flow rate of SiH4. Hydrogen radicals generated from C3H8 decomposition by plasma increase with increasing the flow rate of C3H8, and play important rolls to keep epitaxial growth.
Authors: Jörg Pezoldt, Efstathios K. Polychroniadis, Thomas Stauden, Gernot Ecke, Thierry Chassagne, P. Vennéguès, André Leycuras, D. Panknin, J. Stoemenos, Wolfgang Skorupa
Abstract: The influence of the different additions to the melt on the nucleation behavior during short time flash lamp processing was investigated. It was observed that germanium and carbon additions to the silicone melt led to an increase of the mass transport to the growing surface and to an increase of the nuclei size. In the case of germanium additions to the silicon melt an incorporation of germanium in the silicon substrate was observed.
Authors: M. Smith, R.A. McMahon, Wolfgang Skorupa, M. Voelskow, J. Stoemenos
Abstract: This paper gives an insight into the thermal modeling of the i-FLASiC process, which is the flash lamp annealing of a 3C-SiC and silicon multilayer system. The model uses a standard heat flow model combined with an advanced multilayer optical model. Results from the model are consistent with experimentally observed phenomenon and have been used to explain diffusion mechanisms for the LPE of SiC.
Authors: A. Shoji, Mitsutaka Nakamura, K. Mitikami, Toshiyuki Isshiki, Satoru Ohshima, Shigehiro Nishino
Abstract: The pendeo epitaxial growth has been applied for the growth of 3C-SiC on (001) Si substrates. This growth was performed by VPE using hexamethyldisilane (HMDS) as a source gas. To characterize the crystallinity of the seed 3C-SiC and the pendeo epitaxial layer, the high resolution transmission electron microscopic (HRTEM) analysis was carried out. In the vertically grown layer on the seed 3C-SiC, the high-defect-density regions were observed. On the contrary, the low-defect-density regions were observed in the laterally grown layer. It was revealed from the TEM observations that lattice information can be transferred through the seed 3C-SiC while defects can be prevented from propagating into the epitaxial layer due to the presence of the air gap.
Authors: Didier Chaussende, Laurence Latu-Romain, Laurent Auvray, M. Ucar, Michel Pons, Roland Madar
Abstract: Thick (111) oriented β-SiC layers have been grown by hetero-epitaxy on a (0001) a-SiC substrate with the Continuous Feed-Physical Vapour Transport (CF-PVT) method. The growth rate was 68 µm/h at a pressure of 2 torr and a temperature of 1950°C. The nucleation step of the β-SiC layer during the heating up of the process was studied in order to manage first the a to b heteropolytypic transition and second the selection of the b-SiC orientation. With a adapted seeding stage, we grew a 0.4mm thick layer almost free of Double Positioning Boundaries on a 30mm diameter sample. First observations of the layer by cross-polarised optical Microscopy are presented both in planar view and in cross section geometry.
Authors: Efstathios K. Polychroniadis, Carole Balloud, Sandrine Juillaguet, Gabriel Ferro, Yves Monteil, Jean Camassel, J. Stoemenos
Abstract: The evolution of defects versus thickness has been investigated in three different freestanding 3C-SiC samples, using TEM (Transmission Electron Microscopy) and LTPL (Low Temperature Photo-Luminescence) spectroscopy. In all samples, the stacking fault density reduces rapidly within the first 20 µm of the growth. Then it remains constant, at about 5x103 cm-1 up to the end. This behavior is attributed to the easy generation of stacking faults, even under a very low thermal stress, as in-situ experiments reveal. On the opposite the elimination of inversion domains, by bending boundaries during the growth, is found to be sample dependant. This is in good agreement with LTPL results.
Authors: M. Voelskow, D. Panknin, Efstathios K. Polychroniadis, Gabriel Ferro, Phillippe Godignon, Narcis Mestres, Wolfgang Skorupa, Yves Monteil, J. Stoemenos
Abstract: An approach for the defect density reduction in 3C-SiC epitaxially grown on Si is to improve the quality of the carbonized layer during the early stage of growth. For this reason the conventional carbonization process was replaced by a slower and nearer equilibrium carbonization method. Carbon is introduced by implantation into oxide of an oxidized Si substrate, near the SiO2/Si interface, and then it is transferred to the Si surface by annealing. Good quality 3C-SiC grains are formed embedded into the Si substrate, which are absolutely flat at the SiO2/Si interface. Another advantage of the new carbonization process is the elimination of the cavities due to the suppression of Si out-diffusion.
Authors: T. Nakata, Y. Ohshiro, A. Shoji, Yoichi Okui, Satoru Ohshima, Yoshihiko Hayashi, Shigehiro Nishino
Abstract: The selective growth of Si column was carried out by depositing Au on patterned Si (111) substrate as a solvent in chemical vapor transport method by using halides (HCl). The Si column was produced by VLS mechanism. The column was covered with SiC by conventional CVD process using HMDS ( Hexamethyldisilane ). Carbon Nano Tube ( CNT ) was deposited on Si column covered with SiC by DC assisted µ-wave plasma CVD.
Authors: Mikael Syväjärvi, L. Nasi, Gholam Reza Yazdi, Giancarlo Salviati, M. Izadifard, I.A. Buyanova, W.M. Chen, Rositza Yakimova
Abstract: Ferromagnetic phases in as-grown SiC have been studied. An interpretation about the formation based on details of the phase appearance in the layers from optical microscopy, AFM, and TEM investigations is related to the growth. Some phases were found to have a nucleation at the edge of the phase and detailed TEM investigations show that the phases have an increased grain density at the edge while the main part of the phase is monocrystalline.

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