【作者】 宋曦；

【导师】 谢二庆； 谢常青；

【作者基本信息】 兰州大学 ， 光学， 2010， 硕士

【摘要】 碳化硅(SiC)被誉为下一代半导体材料,因为其具有众多优异的物理化学特性,被广泛应用于光电器件、高频大功率、高温电子器件。本文着眼其优异的机械力学特性及良好的光学特性,将用PECVD方法制备SiC薄膜应用在制作极紫外探测器上的核心色散元件(透射光栅)上。因为它具有热导率大、抗辐射能力强、热容高、良好的化学稳定性、热膨胀系数与硅基十分接近等等优点,所以成为制作在极端恶劣的近地空间环境下的极紫外探测器上核心元件的首选材料。在本研究工作中,采用等离子体增强化学气象沉积(PECVD)制备方法,针对实际应用需要,在单晶Si(100)衬底上,通过工艺参数的改变,在高温衬底上沉积得到了的SiC薄膜,然后进行表征测试,并通过表征结果来进一步优化工艺参数和退火参数,最终成功制作出高质量的5mm X 5mm的自支撑薄膜和最大面积35mm×35mm的自支撑薄膜。最后讨论了其制作的工艺流程以及用它制作极紫外透射光栅的工艺步骤。由于实际应用的迫切需要,然而SiC自支撑薄膜制作透射光栅的工艺尚不成熟,所以接下来用目前工艺成熟的PI膜代替SiC薄膜制作出来的2000线／毫米极紫外透射光栅,为了实现极紫外透射光栅光谱仪在近地空间的应用,采用有限元方法建立了机械模型并对其热学性能和耦合特性进行计算机模拟计算,通过模拟热膨胀系数不同的材料构成的薄膜光栅在近地空间受到太阳辐照后的温度场,得到该光栅表面的热形变分布。结果表明,在高真空热环境下,该透射光栅表面形变量平均可达0.56μm,而影响光栅周期的纵向形变平均值则为71.5nm。由于热形变会对光栅衍射效率产生重要影响并导致光谱仪精度和性能的下降,利用有限元分析模拟的结果,进一步优化光栅的封装和设计制作,使其栅线处纵向热形变趋近于零,为2000线／毫米×／EUV透射光栅在太阳极紫外辐射探测器上得到应用提供了科学依据和有效支持。更多还原

【Abstract】 As well known, Silicon carbide (SiC) has been considered as one of the next generation of semiconductor materials, due to its excellent physical and chemical properties, which make it wide applications in high-frequency, high-power, and high temperature optoelectronic devices. Based on their excellent mechanical and optical properties, this dissertation was mainly focused on applying SiC films as one of the important dispersion elements in the extreme ultraviolet detectors, i.e. transmission grating. Moreover, SiC should be one of the preferred materials that can be used as the key component of extreme ultraviolet (EUV) detectors, which can work under the extremely hard environment of Near-Earth space, owing to their high thermal conductivity, strong radiation resistance, high thermal capacitance, and excellent chemical inertness.In this dissertation, SiC films were prepared by using plasma enhanced chemical vapor deposition (PECVD). According as the requirements of the practical applications, SiC films were prepared under high temperatures on the single crystal Si (100) substrates. The films prepared under different process parameters were characterized by various techniques. Based on the results of the characterization of the samples, the CVD and annealing parameters have been further optimized. Finally, the high-quality self-supporting films with area of 5×5 cm2 were successfully prepared. Additionally, the technical processes of the preparation of this type self-supporting films and further applications in extreme ultraviolet transmission grating were discussed in details.Because the technical processes of the preparation of the extreme ultraviolet transmission grating using self-supporting SiC films are still under research, commercial PI films were used instead of SiC ones to prepare 2000 1/mm X/EUV transmission grating in the latter work. In order to meet the requirements of the EUV transmission grating spectrometer in Near-Earth space, a mechanical model based on the finite element method was used to simulate the thermal and coupling properties of the transmission grating. Based on the simulation under the influence of the temperature field from the Sun in Near-Earth space, the thermal distortion distribution was obtained for the transmission grating with different coefficient of thermal expansion. The results indicate that the average surface distortion of the transmission grating can reach up to 0.56μm under high-vacuum thermal environments, while the average longitudinal distortion, which often shows a significant impact on the period of the gratings, is 71.5nm. Generally, the thermal distortion will show a huge influence on the diffraction efficiency of the transmission grating, further lead to the reduced behaviors and accuracies of the spectroscopic instruments. Thus, based on the results by the finite element simulation, the techniques of the package and designs were further optimized to prepare the transmission gratings with longitudinal distortion of zero at the grating lines. Our research may provide some effective scientific basis and effective support for the application of 2000 1/mm X/EUV transmission gratings in the solar EUV radiation spectroscopy.更多还原