Author Affiliations
Abstract
Shaanxi Provincial Key Laboratory of Thin Films Technology and Optical Test, Xi’an Technological University, Xi’an 710021, China
The plasma-enhanced chemical vapor deposition (PECVD) technique is well suited for fabricating optical filters with continuously variable refractive index profiles; however, it is not clear how the optical and structural properties of thin films differ when deposited on different substrates. Herein, silicon nitride films were deposited on silicon, fused silica, and glass substrates by PECVD, using silane and ammonia, to investigate the effects of the substrate used on the optical properties and structures of the films. All of the deposited films were amorphous. Further, the types and amounts of Si-centered tetrahedral Si–SivN4-v bonds formed were based upon the substrates used; Si–N4 bonds with higher elemental nitrogen content were formed on Si substrates, which lead to obtaining higher refractive indices, and the Si–SiN3 bonds were mainly formed on glass and fused silica substrates. The refractive indices of the films formed on the different substrates had a maximum difference of 0.05 (at 550 nm), the refractive index of SiNx films formed on silicon substrates was 1.83, and the refractive indices of films formed on glass were very close to those formed on fused silica. The deposition rates of these SiNx films are similar, and the extinction coefficients of all the films were lower than 10?4.
thin films plasma-enhanced chemical vapor deposition optical properties structural properties substrate materials Chinese Optics Letters
2020, 18(8): 083101
1 西北大学 光子学与光子技术研究所, 陕西 西安 710069
2 西北大学 陕西省光电子技术重点实验室, 陕西 西安 710069
分别以铜、铝、有机玻璃、聚四氟乙烯为实验衬底材料, 对采用片式粘敷封装技术的光纤布拉格光栅温度传感增敏特性进行了实验研究。研究结果表明, 当对两侧尾纤有涂覆层的光纤布拉格光栅进行封装时, 其温度灵敏系数分别是裸纤情况下的2.3倍、2.9倍、5.2倍、11.7倍。然而, 粘敷材料在较高温度时显著的热膨胀会引起光纤包层与涂覆层发生一定的脱离, 导致此时其实验结果重复性不甚理想。为了克服这种不利情况, 对尾纤无涂覆层的光纤布拉格光栅进行了封装测试。在测试温度范围内, 其反射波长随温度的变化始终呈现良好的线性关系, 其温度灵敏系数分别提高到了3倍、3.4倍、9.2倍、12.6倍, 测量结果重复性良好。研究结果为将来片式封装光纤布拉格光栅传感器的温度增敏特性的研究, 提供了必要有益的数据支持和参考。
光纤布拉格光栅 温度传感增敏 布拉格波长 衬底材料 片式封装 fiber Bragg grating temperature sensitivity enhancement Bragg wavelength substrate materials slice package 红外与激光工程
2019, 48(11): 1118003
1 湖南大学 电气与信息工程学院， 长沙 410082
2 邵阳职业技术学院 机电工程系，湖南 邵阳 422000
根据传热理论，建立了大功率发光二极管的有限元模型.选择了4种键合材料（高导热导电银胶、纳米银焊膏，大功率芯片键合胶、Sn70Pb30），4种基板材料（Al2O3、AlN、Al-SiC、铜钼合金）.采用ANSYS有限元热分析软件进行了温度场仿真，得到了大功率发光二极管封装材料的最优选择.研究了基板厚度、芯片输出功率及外接热沉时对发光二极管结温的影响.结果表明：纳米银焊膏-AlN组合具有最优的散热效果；增加散热基板厚度提高散热能力的作用不大；单个发光二极管输出功率有限，应优化封装结构并采用多芯片阵列来满足照明级的需要；外接铝热沉能达到理想的散热效果.
大功率发光二极管 封装 键合材料 基板材料 优化 High power Light Emitting Diode(LED) Packaging Bonding materials Substrate materials ANSYS
北京理工大学 光电学院薄膜与显示技术实验室,北京 100081
采用哈特曼夏克传感器的薄膜应力在线测量仪测量了利用离子辅助电子束蒸发的SiO2,TiO2,Ta2O5,Al2O3与ITO薄膜在不同厚度时的应力值,并深入研究了基片材料与沉积参数对SiO2,TiO2薄膜应力的影响。研究结果表明,在成膜的初始阶段,薄膜应力与薄膜厚度基本上呈线性函数,当达到一定厚度时薄膜应力基本趋于一个定值;薄膜与基片的热失配将引起薄膜热应力,通过选择合适的基片材料可以使其降低;对TiO2薄膜而言,当基片温度低于150 ℃时,热应力起主要作用,当基片温度高于150 ℃时,薄膜致密引起的压应力占主导地位,但SiO2薄膜其热应力始终占主导地位;当真空室压强低于1.7×10-2 Pa时,SiO2薄膜的张应力主要是由离子辅助溅射效应而引起,当真空室压强高于1.7×10-2 Pa时,SiO2薄膜的张应力随着压强的增大而增大,但折射率减小。
薄膜光学 薄膜应力 哈特曼夏克传感器 基片材料 沉积参数 离子辅助沉积
