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61.
基于化学气相反应法,以高纯Si和SiO2为反应源材料,在碳纤维表面原位生长β-SiC纳米纤维。采用XRD、SEM和TEM 等分析测试手段对SiC纳米纤维进行了表征分析,研究了不同反应温度和时间对生成β-SiC纳米纤维微观形貌和结构的影响,并探讨了β-SiC纳米纤维的生长机制。研究结果表明:采取化学气相反应法能够制备高质量、高纯度的β-SiC纳米纤维,纳米纤维的直径约为100~300 nm。随着反应温度的提高和时间的延长,纳米纤维的产额增加,且微观组织形貌发生了变化。结合制备过程和纳米纤维微观结构的观察分析,表明气-固(VS)机制是SiC纳米纤维生长的主要机理。 相似文献
62.
Graphene is scientifically and commercially important because of its unique molecular structure which is monoatomic in thickness, rigorously two-dimensional and highly conjugated. Consequently, graphene exhibits exceptional electrical, optical, thermal and mechanical properties. Herein, we critically discuss the surface modification of graphene, the specific advantages that graphene-based materials can provide over other materials in sensor research and their related chemical and electrochemical properties. Furthermore, we describe the latest developments in the use of these materials for sensing technology, including chemical sensors and biosensors and their applications in security, environmental safety and diseases detection and diagnosis. 相似文献
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65.
SiC MESFET反向截止漏电流的研究 总被引:2,自引:0,他引:2
给出了一种减小SiC MESFET栅漏反向截止漏电流的工艺方法,通过采用LPCVD淀积厚SiO2和高温氧化工艺,使器件的性能得到一定的提升.从实验数据看出,器件在S波段工作时,器件的反向截止漏电流大幅度下降,且分散性得到改善,其功率附加效率和功率增益也分别提高了10%和1.5 dB.该方法充分发挥了SiC材料能形成自身氧化层的优势,结合Si工艺的特点,减小了氧化层的缺陷,并在一定程度上减小了器件的寄生电容. 相似文献
66.
Dayin Xu 《Microelectronic Engineering》2006,83(1):89-91
Anodic aluminum oxide (AAO) template was prepared by a two-step anodization method at low temperature (1 °C) and silicon carbide was deposited on the templates by non-reactive radio frequency sputtering method. Well-aligned quasi-one dimension silicon carbide nanorods with the average diameter about 80-90 nm and a mean length of 400 nm were obtained perpendicular to the substrate and observed by AFM and SEM after the aluminum substrates were striped off. Then some samples were annealing at flowing N2 at 400, 500 and 600 °C and FTIR was performed on these samples to obtain the information of structure. 相似文献
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68.
S. S. Hullavarad R. D. Vispute B. Nagaraj V. N. Kulkarni S. Dhar T. Venkatesan K. A. Jones M. Derenge T. Zheleva M. H. Ervin A. Lelis C. J. Scozzie D. Habersat A. E. Wickenden L. J. Currano M. Dubey 《Journal of Electronic Materials》2006,35(4):777-794
In this paper we report recent advances in pulsed-laser-deposited AIN thin films for high-temperature capping of SiC, passivation
of SiC-based devices, and fabrication of a piezoelectric MEMS/NEMS resonator on Pt-metallized SiO2/Si. The AlN films grown using the reactive laser ablation technique were found to be highly stoichiometric, dense with an
optical band gap of 6.2 eV, and with a surface smoothness of less than 1 nm. A low-temperature buffer-layer approach was used
to reduce the lattice and thermal mismatch strains. The dependence of the quality of AlN thin films and its characteristics
as a function of processing parameters are discussed. Due to high crystallinity, near-perfect stoichiometry, and high packing
density, pulsed-laser-deposited AlN thin films show a tendency to withstand high temperatures up to 1600°C, and which enables
it to be used as an anneal capping layer for SiC wafers for removing ion-implantation damage and dopant activation. The laser-deposited
AlN thin films show conformal coverage on SiC-based devices and exhibit an electrical break-down strength of 1.66 MV/cm up
to 350°C when used as an insulator in Ni/AlN/SiC metal-insulator-semiconductor (MIS) devices. Pulsed laser deposition (PLD)
AlN films grown on Pt/SiO2/Si (100) substrates for radio-frequency microelectrical and mechanical systems and nanoelectrical and mechanical systems
(MEMS and NEMS) demonstrated resonators having high Q values ranging from 8,000 to 17,000 in the frequency range of 2.5–0.45
MHz. AlN thin films were characterized by x-ray diffraction, Rutherford backscattering spectrometry (in normal and oxygen
resonance mode), atomic force microscopy, ultraviolet (UV)-visible spectroscopy, and scanning electron microscopy. Applications
exploiting characteristics of high bandgap, high bond strength, excellent piezoelectric characteristics, extremely high chemical
inertness, high electrical resistivity, high breakdown strength, and high thermal stability of the pulsed-laser-deposited
thin films have been discussed in the context of emerging developments of SiC power devices, for high-temperature electronics,
and for radio frequency (RF) MEMS. 相似文献
69.
A procedure for producing arrays of self-aligned carbon nanotubes (CNTs) using standard chemical vapor deposition (CVD) is
reported. Using UV photolithography, silicon substrates are patterned with a thin layer of thermally evaporated iron as a
CNT catalyst. The CVD synthesis was carried out over a small temperature range (700°C–800°C) using acetylene and methane gasses,
producing aligned CNT towers. Scanning electron microscopy (SEM) analysis shows a relationship between CNT tower height and
synthesis time. Additionally, results show that impurity particles dramatically effect CNT tower growth. These results indicate
that aligned CNTs can be produced in a desired pattern with height control. 相似文献
70.
采用连通式双反应室高温MOCVD系统在Si衬底上外延ZnO薄膜,通过卢瑟福背散射/沟道(RBS/C)及高分辨X射线衍射(HR-XRD)技术对不同衬底条件的ZnO外延膜进行了组分及结构分析,结果表明在采用SiC缓冲层后,Si(111)衬底上ZnO(0002)面衍射峰半高宽明显减小,缺陷密度降低,单晶质量显著变好,c轴方向应变由0.49%变为-0.16%,即由拉应变变为压应变且应变值变小,说明SiC缓冲层可以有效地减小ZnO与Si衬底晶格失配带来的应变,改善外延膜质量,实现Si衬底上单晶ZnO的生长. 相似文献