Effects of CH2F2 and H2 flow rates on process window for infinite etch selectivity of silicon nitride to ArF PR in dual-frequency CH2F2/H2/Ar capacitively coupled plasmas

The process window for the infinite etch selectivity of silicon nitride (Si₃N₄) layers to ArF photoresist (PR) and ArF PR deformation were investigated in a CH₂F₂/H₂/Ar dual-frequency superimposed capacitive coupled plasma (DFS-CCP) by varying the process parameters, such as the low frequency power (P_LF), CH₂F₂ flow rate, and H₂ flow rate. It was found that infinitely high etch selectivities of the Si₃N₄ layers to the the ArF PR on both the blanket and patterned wafers could be obtained for certain gas flow conditions. The H₂ and CH₂F₂ flow rates were found to play a critical role in determining the process window for infinite Si₃N₄/ArF PR etch selectivity, due to the change in the degree of polymerization. The preferential chemical reaction of hydrogen with the carbon in the hydrofluorocarbon (CH_xF_y) layer and the nitrogen on the Si₃N₄ surface, leading to the formation of HCN etch by-products, results in a thinner steady-state hydrofluorocarbon layer and, in turn, in continuous Si₃N₄ etching, due to enhanced SiF₄ formation, while the hydrofluorocarbon layer is deposited on the ArF photoresist surface.     

低插损同轴型微波介质滤波器的设计

1/4波长同轴谐振器构成的微波介质带通滤波器,具有三个谐振孔、二个耦合孔,谐振器间通过耦合孔相互耦合,材料采用高介电常数微波陶瓷,器件表面涂覆金属电极。讨论了耦合孔半径对滤波器技术指标(中心频率f_0、3dB带宽B、插入损耗L_0、阻带抑制L_A等)的影响,然后根据给定的滤波器技术指标确定了滤波器的类型、结构、级数及尺寸,最后进行了仿真验证,得到了低损耗的带通滤波器。     

光纤耦合声光调制器键合膜系设计与制备

为了实现超高速的声光调制,该文提出了一种光纤耦合声光调制器键合膜系的设计与仿真方法。利用该方法设计并制作了一款工作频率为200 MHz、10 ns光脉冲上升时间的光纤耦合声光调制器。器件采用TeO2作为声光介质,36°Y 切LiNbO3作为压电换能器晶片,衬底层采用高纯度Cr,键合层为高纯度Au,结果表明器件性能测试良好。     

Blind signal separation for coprime planar arrays: An improved coupled trilinear decomposition method

In this study, the problem of blind signal separation for coprime planar arrays is investigated. For coprime planar arrays comprising two uniform rectangular subarrays, we link the signal separation to the tensor-based model called coupled canonical polyadic decomposition (CPD) and propose an improved coupled trilinear decomposition approach. The output data of coprime planar arrays are modeled as a coupled tensor set that can be further interpreted as a coupled CPD model, allowing a signal separation to be achieved using coupled trilinear alternating least squares (TALS). Furthermore, in the procedure of the coupled TALS, a Vandermonde structure enforcing approach is explicitly applied, which is shown to ensure fast convergence. The results of Monto Carlo simulations show that our proposed algorithm has the same separation accuracy as the basic coupled TALS but with a faster convergence speed.     

基于非对称耦合螺旋谐振器的顺序旋转馈电网络设计

基于一种新型超材料单元——非对称耦合螺旋谐振器,提出了基于该单元的顺序旋转馈电网络设计方案。由于螺旋谐振器的内卷几何特性,非对称耦合螺旋谐振器尺寸非常紧凑。同时,研究发现,该单元的-90°相移频率大致与通带中心频率对应,对于设计正交相移微波器件具有重要价值。由于非对称耦合螺旋谐振器的上述优点,提出的馈电网络结构具有小型化和调试简单等优点。测试结果表明,该馈电网络能够较好地满足顺序旋转馈电的要求。     

AlGaN/GaN HEMT 2DEG电致耦合模型的研究

传统计算AlGaN/GaN异质结二维电子气(2DEG)的方法是根据Hooke定律计算c轴方向压应变与拉应变,然后利用压电模量计算出不依赖于栅压的2DEG,称为非耦合模型计算.提出了一种电致耦合模型来计算2DEG,在计算过程中考虑到弛豫度与附加电场对材料压电效应的影响,结果发现,当Al组分x=0.30时,压电极化电荷密度低于传统方法的计算值,两种模型的计算值相差7.17%,由此可见,当电场作用于材料时,材料产生逆压电效应,最终导致压电极化电荷密度降低.     

高速CCD相机系统设计

采用KAF-1001芯片研制出了高速科学CCD相机.详细介绍了CCD相机的数据采集原理,CPLD在CCD时序中的控制,FX2系列CY7C68013 USB芯片在高速CCD相机数据传输上的运用及利用VC++开发的相机图像采集软件.通过对开发的样机所做的实验及数据分析表明,相机性能达到了高速科学CCD相机的要求,并提供了CCD相机的各项技术指标.     

基于蛾眼阵列的全向宽光谱减反层优化设计

为降低太阳电池封装材料PET薄膜的反射率,采用严格耦合波分析(RCWA)方法对基于蛾眼阵列的减反层进行了优化设计。对比研究了圆锥形、抛物线形和正弦形蛾眼结构的减反性能,结果表明圆锥形蛾眼结构具有最佳全向宽光谱减反性能。分析了圆锥体几何参数对太阳光透过率的影响,为参数选取提供依据。在此基础上,提出基于柱形与锥形复合结构的蛾眼阵列,通过参数优化,进一步提高了太阳光在大角度入射条件下的透过率。优化后复合结构的蛾眼阵列的PET薄膜对波长范围在0.3~1.1μm、入射角度为0°~90°的入射太阳光角度归一化透过率达到0.966 4,相比于未采取减反措施的PET薄膜透过率提高12.77%。     

基于场积分方程的机箱耦合电流特性的数值分析

各种电子电器设备都有外接导线,例如通讯线、信号线、电源线等。虽然电子电器设备本身可以通过屏蔽体抵御外部的电磁干扰,但是外部的电磁干扰仍然可以通过暴露在屏蔽体外的导线直接将电磁能量耦合到蔽体内部,使屏蔽体内的电磁环境变得更加复杂。文章依据边界条件推导出电磁场积分方程,并通过矩量法计算了导线与机箱外壳连接点的感应电流强度,在导线的半径、入射电场的极化方向和导线间距等各种因素影响下,通过理论得出模拟曲线,发现耦合电流随频率的一些变化规律。     

网络化协同系统分析与设计

基于网络的协同系统是提升产品协同设计能力的可行途径,采用基于网络的疏松耦合式协同设计框架,建立模块化、基于网络的协同设计系统的通用模型,能够改善企业与企业间在线协同产品开发的困难局面,增强产品协同研发效率。