3C-SiC又称β-SiC,有着优异的耐高温、耐腐蚀、耐辐照性能,是反应堆这类复杂环境中的理想材料。近年来,一维碳化硅纳米线材料成为碳化硅材料研究领域的热门研究方向,同时也面临加工手段匮乏、加工难度大的问题。我们通过化学气相沉积法...3C-SiC又称β-SiC,有着优异的耐高温、耐腐蚀、耐辐照性能,是反应堆这类复杂环境中的理想材料。近年来,一维碳化硅纳米线材料成为碳化硅材料研究领域的热门研究方向,同时也面临加工手段匮乏、加工难度大的问题。我们通过化学气相沉积法成功制备了含有高密度堆叠层错的3C-SiC纳米线,并采用扫描电子显微镜(Scanning Electron Microscope,SEM)、透射电子显微镜(Transmission Electron Microscope,TEM)、X射线衍射(X-Ray Diffraction,XRD)以及拉曼光谱(Raman spectrum)等多种手段对制备出来的碳化硅纳米线进行了微观结构表征,揭示了其独特的微观形态和晶体结构特征;进一步研究了超声裁剪碳化硅纳米线,利用“气泡-射流”模型结合碳化硅纳米线的形态解释了碳化硅纳米线的超声裁剪过程,探索了碳化硅纳米线的直径、强度、缺陷等对其在超声过程中断裂行为的影响。本研究为碳化硅纳米线的超声裁剪加工和纳米线的强度研究提供了新的视角,对于未来碳化硅纳米线在核能领域的应用具有重要的意义。展开更多
This study delves into the charge transfer mechanism of boron (B)-doped 3C-SiC through first-principles investigations. We explore the effects of B doping on the electronic properties of 3C-SiC, focusing on a 12.5% im...This study delves into the charge transfer mechanism of boron (B)-doped 3C-SiC through first-principles investigations. We explore the effects of B doping on the electronic properties of 3C-SiC, focusing on a 12.5% impurity concentration. Our comprehensive analysis encompasses structural properties, electronic band structures, and charge density distributions. The optimized lattice constant and band gap energy of 3C-SiC were found to be 4.373 Å and 1.36 eV respectively, which is in agreement with previous research (Bui, 2012;Muchiri et al., 2018). Our results show that B doping narrows the band gap, enhances electrical conductivity, and influences charge transfer interactions. The charge density analysis reveals substantial interactions between B dopants and surrounding carbon atoms. This work not only enhances our understanding of the material’s electronic properties, but also highlights the importance of charge density analysis for characterizing charge transfer mechanisms and their implications in the 3C-SiC semiconductors.展开更多
Highly oriented voids-free 3C-SiC heteroepitaxial layers are grown onφ50mm Si (100) substrates by low pressure chemical vapor deposition (LPCVD).The initial stage of carbonization and the surface morphology of carbon...Highly oriented voids-free 3C-SiC heteroepitaxial layers are grown onφ50mm Si (100) substrates by low pressure chemical vapor deposition (LPCVD).The initial stage of carbonization and the surface morphology of carbonization layers of Si (100) are studied using reflection high energy electron diffraction (RHEED) and scanning electron microscopy (SEM).It is shown that the optimized carbonization temperature for the growth of voids-free 3C-SiC on Si (100) substrates is 1100℃.The electrical properties of SiC layers are characterized using Van der Pauw method.The I-V,C-V,and the temperature dependence of I-V characteristics in n-3C-SiC/p-Si heterojunctions with AuGeNi and Al electrical pads are investigated.It is shown that the maximum reverse breakdown voltage of the n-3C-SiC/p-Si heterojunction diodes reaches to 220V at room temperature.These results indicate that the SiC/Si heterojunction diode can be used to fabricate the wide bandgap emitter SiC/Si heterojunction bipolar transistors (HBT's).展开更多
Single crystalline 3C-SiC epitaxial layers are grown on φ 50mm Si wafers by a new resistively heated CVD/LPCVD system,using SiH_4,C_2H_4 and H_2 as gas precursors.X-ray diffraction and Raman scattering measurements a...Single crystalline 3C-SiC epitaxial layers are grown on φ 50mm Si wafers by a new resistively heated CVD/LPCVD system,using SiH_4,C_2H_4 and H_2 as gas precursors.X-ray diffraction and Raman scattering measurements are used to investigate the crystallinity of the grown films.Electrical properties of the epitaxial 3C-SiC layers with thickness of 1～3μm are measured by Van der Pauw method.The improved Hall mobility reaches the highest value of 470cm 2/(V·s) at the carrier concentration of 7.7×10 17 cm -3 .展开更多
Heteroepitaxial growth of 3C-SiC on patterned Si substrates by low pressure chemical vapor deposition （LPCVD） has been investigated to improve the crystal quality of 3C-SiC films. Si substrates were patterned with p...Heteroepitaxial growth of 3C-SiC on patterned Si substrates by low pressure chemical vapor deposition （LPCVD） has been investigated to improve the crystal quality of 3C-SiC films. Si substrates were patterned with parallel lines,1 to 10μm wide and spaced 1 to 10μm apart,which was carried out by photolithography and reactive ion etching. Growth behavior on the patterned substrates was systematically studied by scanning electron microscopy （SEM）. An airgap structure and a spherical shape were formed on the patterned Si substrates with different dimensions. The air gap formed after coalescence reduced the stress in the 3C-SiC films, solving the wafer warp and making it possible to grow thicker films. XRD patterns indicated that the films grown on the maskless patterned Si substrates were mainly composed of crystal planes with （111） orientation.展开更多
文摘3C-SiC又称β-SiC,有着优异的耐高温、耐腐蚀、耐辐照性能,是反应堆这类复杂环境中的理想材料。近年来,一维碳化硅纳米线材料成为碳化硅材料研究领域的热门研究方向,同时也面临加工手段匮乏、加工难度大的问题。我们通过化学气相沉积法成功制备了含有高密度堆叠层错的3C-SiC纳米线,并采用扫描电子显微镜(Scanning Electron Microscope,SEM)、透射电子显微镜(Transmission Electron Microscope,TEM)、X射线衍射(X-Ray Diffraction,XRD)以及拉曼光谱(Raman spectrum)等多种手段对制备出来的碳化硅纳米线进行了微观结构表征,揭示了其独特的微观形态和晶体结构特征;进一步研究了超声裁剪碳化硅纳米线,利用“气泡-射流”模型结合碳化硅纳米线的形态解释了碳化硅纳米线的超声裁剪过程,探索了碳化硅纳米线的直径、强度、缺陷等对其在超声过程中断裂行为的影响。本研究为碳化硅纳米线的超声裁剪加工和纳米线的强度研究提供了新的视角,对于未来碳化硅纳米线在核能领域的应用具有重要的意义。
文摘This study delves into the charge transfer mechanism of boron (B)-doped 3C-SiC through first-principles investigations. We explore the effects of B doping on the electronic properties of 3C-SiC, focusing on a 12.5% impurity concentration. Our comprehensive analysis encompasses structural properties, electronic band structures, and charge density distributions. The optimized lattice constant and band gap energy of 3C-SiC were found to be 4.373 Å and 1.36 eV respectively, which is in agreement with previous research (Bui, 2012;Muchiri et al., 2018). Our results show that B doping narrows the band gap, enhances electrical conductivity, and influences charge transfer interactions. The charge density analysis reveals substantial interactions between B dopants and surrounding carbon atoms. This work not only enhances our understanding of the material’s electronic properties, but also highlights the importance of charge density analysis for characterizing charge transfer mechanisms and their implications in the 3C-SiC semiconductors.
文摘Highly oriented voids-free 3C-SiC heteroepitaxial layers are grown onφ50mm Si (100) substrates by low pressure chemical vapor deposition (LPCVD).The initial stage of carbonization and the surface morphology of carbonization layers of Si (100) are studied using reflection high energy electron diffraction (RHEED) and scanning electron microscopy (SEM).It is shown that the optimized carbonization temperature for the growth of voids-free 3C-SiC on Si (100) substrates is 1100℃.The electrical properties of SiC layers are characterized using Van der Pauw method.The I-V,C-V,and the temperature dependence of I-V characteristics in n-3C-SiC/p-Si heterojunctions with AuGeNi and Al electrical pads are investigated.It is shown that the maximum reverse breakdown voltage of the n-3C-SiC/p-Si heterojunction diodes reaches to 220V at room temperature.These results indicate that the SiC/Si heterojunction diode can be used to fabricate the wide bandgap emitter SiC/Si heterojunction bipolar transistors (HBT's).
文摘Single crystalline 3C-SiC epitaxial layers are grown on φ 50mm Si wafers by a new resistively heated CVD/LPCVD system,using SiH_4,C_2H_4 and H_2 as gas precursors.X-ray diffraction and Raman scattering measurements are used to investigate the crystallinity of the grown films.Electrical properties of the epitaxial 3C-SiC layers with thickness of 1～3μm are measured by Van der Pauw method.The improved Hall mobility reaches the highest value of 470cm 2/(V·s) at the carrier concentration of 7.7×10 17 cm -3 .
文摘Heteroepitaxial growth of 3C-SiC on patterned Si substrates by low pressure chemical vapor deposition （LPCVD） has been investigated to improve the crystal quality of 3C-SiC films. Si substrates were patterned with parallel lines,1 to 10μm wide and spaced 1 to 10μm apart,which was carried out by photolithography and reactive ion etching. Growth behavior on the patterned substrates was systematically studied by scanning electron microscopy （SEM）. An airgap structure and a spherical shape were formed on the patterned Si substrates with different dimensions. The air gap formed after coalescence reduced the stress in the 3C-SiC films, solving the wafer warp and making it possible to grow thicker films. XRD patterns indicated that the films grown on the maskless patterned Si substrates were mainly composed of crystal planes with （111） orientation.
基金The project supported by the National Natural Science Foundation of China (No.50532070,50472009,90201038,10474091)Foundation of Scientific Research of Henan University(No.06YBZR022)
