集成电极的PDMS-玻璃微流控芯片的制备

微流控芯片在分析化学和生物检测方面有着广阔的应用前景。对集成电极的PDMS-玻璃微流控芯片的制备工艺进行了研究与分析。最终使用SU-8快速制备阳模,使用PDMS转移图形得到具有微流控通道的PDMS盖片;在玻璃基板上加工Pt电极,除了需要外露的部分电极外,其他部分以薄层PDMS保护,得到电极基板;将PDMS盖片与电极基板半固化键合制得同时具有加热和温度传导电极以及CE高压电极的PDMS-玻璃芯片。ANSYS模拟分析证明加热芯片热惯性小,加热时温度分布效果好。     

碱性抛光液中H_2O_2对铜布线CMP的影响

化学机械平坦化(CMP)过程中,抛光液的化学作用对平坦化效果起着不可替代的作用。介绍了碱性抛光液中氧化剂(H2O2)对铜布线CMP的作用:H2O2对铜的强氧化性可以将铜氧化为离子状态,然后在螯合剂的螯合作用下快速去除铜膜;H2O2对铜的钝化作用可以保护凹处铜膜不被快速去除,从而有效降低高低差。此外,还研究了碱性抛光液中不同H2O2浓度对铜的静态腐蚀速率、动态去除速率及铜布线平坦化结果的影响。研究表明:抛光液对铜的静态腐蚀速率随H2O2浓度的增大逐渐降低然后趋于饱和;铜的动态去除速率随H2O2浓度的增大而逐渐降低;抛光液的平坦化能力随H2O2浓度的增大逐渐增强再趋于稳定。     

多层HgCdTe异质外延材料的热退火应力分析

前期研究采用高温热处理方法,获得了抑制位错的最佳退火条件.通过比对实验,发现不同衬底上HgCdTe表面的CdTe钝化层在热处理过程中对位错的抑制作用各有不同.结合晶格失配应力和热应力对不同异质结构进行理论计算,借助X射线摇摆曲线的倒易空间分析,解释了CdTe钝化层对HgCdTe位错抑制的影响作用.     

A review of silicon-based wafer bonding processes,an approach to realize the monolithic integration of Si-CMOS and Ⅲ-Ⅴ-on-Si wafers

The heterogeneous integration of Ⅲ-Ⅴ devices with Si-CMOS on a common Si platform has shown great promise in the new generations of electrical and optical systems for novel applications,such as HEMT or LED with integrated control cir-cuitry.For heterogeneous integration,direct wafer bonding(DWB)techniques can overcome the materials and thermal mis-match issues by directly bonding dissimilar materials systems and device structures together.In addition,DWB can perform at wafer-level,which eases the requirements for integration alignment and increases the scalability for volume production.In this paper,a brief review of the different bonding technologies is discussed.After that,three main DWB techniques of single-,double-and multi-bonding are presented with the demonstrations of various heterogeneous integration applications.Mean-while,the integration challenges,such as micro-defects,surface roughness and bonding yield are discussed in detail.     

Metallic Glass as a Mechanical Material for Microscanners

Microelectromechanical system (MEMS) actuators essentially have movable silicon structures where the mechanical motion can be activated electronically. The microscanner is one of the most successfully commercialized MEMS devices which are widely used for collecting optical information, manipulating light, and displaying images. While silicon is abundant, it is also brittle and stiff and when microprocessed, defects are not uncommon. These defects result in weakness under torsional stress and this has been the key factor limiting the scanning performance of the microscanner. Here a metallic glass (MG)‐based microscanner is reported with MG as the material for the moving torsion bars. The low elastic modulus, high fracture toughness, and high strength of MG offers, for the first time, an ultralarge rotating angle of 146° with power consumption lowered to the microwatt range, and a smaller driving force and better actuation performance, than conventional single crystal silicon and polycrystalline silicon. The high spatial resolution and large scanning field of the MG‐based microscanner are demonstrated in the tomographic imaging of a human finger. This development of an MG‐based MEMS possibly opens a new field of low‐powered MEMS devices with extreme actuation and enhanced sensing.     

Rear‐Passivated Ultrathin Cu(In,Ga)Se2 Films by Al2O3 Nanostructures Using Glancing Angle Deposition Toward Photovoltaic Devices with Enhanced Efficiency

In this work, for the first time, the addition of aluminum oxide nanostructures (Al₂O₃ NSs) grown by glancing angle deposition (GLAD) is investigated on an ultrathin Cu(In,Ga)Se₂ device (400 nm) fabricated using a sequential process, i.e., post‐selenization of the metallic precursor layer. The most striking observation to emerge from this study is the alleviation of phase separation after adding the Al₂O₃ NSs with improved Se diffusion into the non‐uniformed metallic precursor due to the surface roughness resulting from the Al₂O₃ NSs. In addition, the raised Na concentration at the rear surface can be attributed to the increased diffusion of Na ion facilitated by Al₂O₃ NSs. The coverage and thickness of the Al₂O₃ NSs significantly affects the cell performance because of an increase in shunt resistance associated with the formation of Na₂Se_X and phase separation. The passivation effect attributed to the Al₂O₃ NSs is well studied using the bias‐EQE measurement and J–V characteristics under dark and illuminated conditions. With the optimization of the Al₂O₃ NSs, the remarkable enhancement in the cell performance occurs, exhibiting a power conversion efficiency increase from 2.83% to 5.33%, demonstrating a promising method for improving ultrathin Cu(In,Ga)Se₂ devices, and providing significant opportunities for further applications.     

宽域氧传感器控制器开发与试验

宽域氧传感器(UEGO)是柴油发动机后处理系统的重要传感器。UEGO传感器结构特殊,需要控制器协同工作。本文以MC9S12XS128为核心设计了一种控制器,采用比例积分微分(PID)加热策略维持传感器的温度,实现对过量空气系数λ的采集与显示。最后利用测试台架对传感器进行了标定,验证了数据有效性。     

基于特征子图的异构信息网络节点相似性度量

为解决异构信息网络相似性度量的问题,提出了基于节点特征子图的节点相似性度量算法,通过节点特征子图的最大公共子图与最小公共超图之间的差异性,进行节点间的相似性度量.该算法以图理论为基础,根据连边的不同类型设定不同权值,在考虑节点信息相似的同时,加入节点在网络中的结构信息,最大程度地利用了异构信息网络所富含的信息.实验结果表明,提出的算法具有较好的性能和有效性.     

“无线传感器网络”教学方法探索

本文介绍物联网工程专业"无线传感器网络"课程的教学探索,提出一种重在实践创新应用的"无线传感器网络"课程四阶段教学法,并对四个阶段分别采用七环WSN实践思路启发法、六环WSN实践方案设计法、四环WSN实践方案实施法以及多维总结评价方法。实践结果表明:重在实践创新应用的"无线传感器网络"课程四阶段教学法能有效提升教学质量,可以加强学生实践创新应用的能力。     

Efficient wet paper embedding for steganography with multilayer construction

This work proposes an efficient data hiding scheme for wet paper channel by using a multilayer construction, in which a number of node-bits in different layers are derived from all cover bits and used to carry the secret data. By applying the wet paper coding method to the node-bits and altering the changeable cover bits, the node-bits are modified into their desired values and the secret data are embedded in a layer-by-layer manner. An equilibration mechanism is also introduced to flip the denser changeable cover bits with higher probability. This way, paper folding method is equivalent to a special case of the proposed scheme, and a family of data hiding methods with more flexible relative payload and higher embedding efficiency can be generated.