采用KrF准分子激光制备聚合酶链式反应微流控芯片

采用价格便宜的聚甲基丙烯酸甲酯(PMMA)代替价格昂贵的硅或者玻璃作为聚合酶链式反应(PCR)微流控芯片的基片材料,采用柔性大、自动化程度高的准分子激光微加工方法代替加工工艺复杂的光刻化学腐蚀方法。通过对聚甲基丙烯酸甲酯准分子激光加工规律的研究,在19kV和18mm/min的优化加工参量下,在40mm×63mm的聚甲基丙烯酸甲酯基片上制备出了20个循环的聚合酶链式反应微流控芯片。芯片微通道横截面呈倒梯形,底面粗糙度小于0.5μm。微通道宽104μm,深56μm,长1040mm,加工耗时57min。该芯片和相同尺寸的盖片在160N和105℃条件下经过20min热压键合在一起,键合强度为0.85MPa。通过进样实验发现键合后的芯片具有良好的密封性。键合后的芯片和温控系统集成在一起,采用比例积分微分(PID)方法得到的控温精度为±0.2℃,采用红外热像仪得到的相邻温区间的温度梯度分别为16.5℃和22.2℃,即该芯片可以实现聚合酶链式反应扩增。     

PMMA基连续流式PCR微流控芯片的CO2激光直写加工与应用

采用CO2激光直写烧蚀加工技术在聚甲基丙烯酸甲酯(PMMA)基片表面加工微通道.分析了CO2激光输出功率和激光束移动速度对加工质量的影响.选用4.5 W输出功率和76.2 mm/s移动速度,在30 s内加工了水力直径为100μm的微通道.在进行微通道的大批量、快速加工时,CO2激光直写烧蚀加工技术具有较高的工艺稳定性,工艺流程简单,可随时根据实验需要时微通道结构进行调整和再加工.微通道的激光拉曼光谱与PMMA基片相同,保证了微通道和盖片对聚合酶链式反应(PCR)物化学影响的一致性.虽然微通道边缘存在少量重铸物,但不会影响热压键合效果.芯片能够满足PCR扩增中的压力与密封要求.使用这种芯片实现了180 bp拟南芥脱氧核糖核酸(DNA)片段的PCR扩增,扩增效果与使用常规PCR仪相当,验证了采用CO2激光直写烧蚀方法加工PMMA基连续流式PCR微流控芯片的可行性.     

PMMA基PCR生物芯片及其准分子激光制备技术的几个关键问题

分析了微流控聚合梅链式反应(PCR)芯片循环的几何结构，对常规非闭环的穿透形式，确定了可行的温区排列结构;对于闭环式的空间分布形式，分析了几种结构的热效率。研究了准分子激光对聚甲基丙烯酸甲脂(PMMA)基片的刻蚀机制，获得了刻蚀曲线。对于PCR 芯片微流通道的加工，着重考虑了通道成形和表面粗糙度问题。其中，采用掩模形状控制法解决通道形状问题;采用激光抛光、近阈值能量、去应力退火等技术提高刻蚀通道的表面质量。在对PMMA基PCR芯片的键合问题研究中，采用了胶粘键合和热压键合两种方案，优选出热压键合的方案，制作了热压键合装置，获得了最佳键合参数，满足键合强度和通道成形要求。针对微流体连续流动的控制问题，研制了一台基于精密气泵结合气动控制的注射进样系统。利用制作的PCR 芯片和进样系统，成功地对170bp的DNA模板进行了扩增。     

PMMA基PCR微流控生物芯片准分子激光加工

采用准分子激光在PMMA基片上刻蚀加工出PCR微流控生物芯片,分析了准分子激光能量密度和工作台移动速度对微通道加工质量(深度及粗糙度)的影响,加工过程中选择较低的激光能量密度和较高的工作台移动速度,都有利于获得底面更加光滑的微通道。通过热键合的方法制备出完整的密闭式PCR微流控生物芯片。     

采用激光制备毛细管电泳芯片微结构的研究

提出了一种采用248 nm准分子激光直写微加工系统制备聚甲基丙烯酸甲酯(PMMA)基毛细管电泳芯片的新方法.主要对毛细管电泳芯片的样品池和微通道进行了实验研究.在19 kV,20 Hz,500个脉冲条件下,厚度为1.5 mm PMMA表面获得直径为1 mm、锥度为4.7 °的池;对宽度均为100 μm,深度不同的微通道底面进行了键合前后比较.最后在键合后宽度为100 μm、深度为30 μm的芯片上成功地完成了进样实验.     

准分子激光微加工技术结合模塑技术加工微流控芯片

利用准分子激光微加工技术与模塑技术相结合的方法制造微流控芯片。用准分子激光在玻璃基胶层上刻蚀出加工质量较高的微流控生物芯片形貌,通过电铸技术对微流控芯片进行复制,得到反向金属模具。用金属模具通过注塑成型技术用聚碳酸酯注塑出微流控芯片。系统研究了准分子激光的能量密度和工作台移动速度对胶层微通道加工质量的影响;测量并分析了激光刻蚀加工出的微流控芯片原型、电铸的反向金属模板和注塑成型后的微流控芯片的轮廓精度和表面粗糙度,上表面尺度偏差不大于2μm,底面粗糙度小于20 nm。对注塑出的微流控芯片和激光直写刻蚀的几何结构相同的微流控芯片的流动性能进行比较测试。在流速较小时,用激光微加工技术与模塑技术相结合的方法加工的微通道比准分子激光直写法所加工的微通道流动性能更好。     

微流控芯片的键合技术

微流控芯片实验室的成品率普遍较低,其中密封技术是微流控芯片制造过程的关键步骤,也是难点之一。玻璃等硬质材料常通过热键合和阳极键合技术实现密封,而节能省时的低温玻璃键合技术更受科研人员的青睐。此外,胶黏剂键合和表面改性键合以其便捷性和实用性的优势成为玻璃和聚合物芯片键合领域重要的部分。常用的聚二甲基硅氧烷(PDMS)和聚甲基丙烯酸甲基(PMMA)高聚物材料则依据其不同的适用场合而采用不同的键合方式。介绍和分析了微流控芯片领域常用的玻璃、PDMS和PMMA材质键合方式,为微流控芯片制备方法提供了技术指向,对提高微流控芯片制作的成品率产生积极的影响。     

基于石蜡打印的PDMS微流控芯片制备及实验应用

介绍了一种基于数字化石蜡液滴微喷射技术制作微流控芯片的方法及其应用,制作的聚二甲基硅氧烷(PDMS)微流控芯片可用于微液滴的生成和两相流的微混合。实验所需玻璃微喷嘴制备简单、成本低廉。石蜡阳模的形状可自主设计,通过调节驱动电压、驱动频率和加热温度可控制石蜡液滴尺寸及石蜡线宽。利用此方法在石英玻璃基底上打印出石蜡阳模,通过PDMS溶液浇注、固化、倒模、清洗再与石英玻璃基板键合等一系列工艺,最终可实现不同内径、不同流道形状的PDMS芯片,制作过程方便快捷,成品质量较好,设计自由度较高。最终通过调整系统各项参量制作出流道内径约为235μm的PDMS微流控芯片,并利用所制作的十字型流道PDMS微流控芯片生成了微液滴,用螺旋形流道的PDMS微流控芯片完成了亮蓝、柠檬黄两种颜色水溶液的微混合。     

一种PMMA表面改性的热压键合方法研究

介绍了一种基于表面改性技术的PMMA热压键合新方法。PMMA表面首先用其单体MMA进行改性，然后在真空热压设备中热压键合。主要的键合参数如下：键合压力0．5MPa～2．5MPa，温度88℃～100℃，时间180s。通过拉力法测量了键合强度，其最大值可达到0．15MPa。实验结果表明，与常规的热压键合方法相比，该方法可有效地降低键合温度，减少键合时间，提高键合强度，从而可减少对PMMA基片上微细图形结构的破坏。使用聚合物的单体（MMA）对PMMA进行改性，可避免对微管道产生化学污染，有利于集成毛细管电泳的生化分析。利用品红和氢氧化钠混合溶液对键合后的微流体芯片进行密封性测试，结果表明，封装后的微流体芯片没有出现泄漏的情况。     

超快激光制备PMMA微流道机理及工艺研究

由于传统加工方法不能解决PMMA微流道的加工质量不好和效率低的问题,本文对超快激光直写PMMA制备微流道的烧蚀机理和工艺参数进行了研究。根据实验分析不同的激光功率、加工速度和加工次数对微流道的宽度和横截面的影响规律,利用超快激光加工系统制备微流道,并采用超景深三维显微镜观测微流道的表面形貌。实验结果表明,当超快激光的加工速度为20 mm/s时,激光功率为1.5 W时,制备的微流道的宽度较小、宽度趋势比较平稳;当超快激光作用PMMA的次数一样,由于加工速度逐渐增加,制备的微流道其宽度和激光的加工速度保持线性增加。当加工速度越大时,微流道的宽度较小、且壁面趋势相对平缓,而当加工速度一定,超快激光的输出功率在1.5 W时,微流道内壁区域不易出现残渣堆积和气泡隆起现象。本文通过优化超快激光加工系统的工艺参数,从而加工出尺寸精度高、表面光滑、宽度为20~90 μm的微流道芯片。     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

Nanoimprint Lithography -A Next Generation High Volume Lithography Technique

IntroductionNanoimprint Lithography is a well-acknowl-edged low cost, high resolution, large area pattern-ing process. It includes the most promising methods,high-pressure hot embossing lithography (HEL) [2],UV-cured imprinting (UV-NIL) [3] and micro contactprinting (m-CP, MCP) [4]. Curing of the imprintedstructures is either done by subsequent UV-lightexposure in the case of UV-NIL or by cooling downbelow the glass transition temperature of the ther-moplastic material in case of HEL…     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.     

Influence of PVK ： NPB hole transporting layer on the characteristics of organic light-emitting devices

A doping system consisting of NPB and PVK is employed as a composite hole transporting layer （CHTL）. By adjusting the component ratio of the doping system, a series of devices with different concentration proportion of PVK ： NPB are constracted. The result shows that doping concentration of NPB enhances the competence of hole transporting ability, and modifies the recombination region of charge as well as affects the surface morphology of doped film. Optimum device with a maximum brightness of 7852 cd/m^2 and a power efficiency of 1.75 lm/W has been obtained by choosing a concentration proportion of PVK ： NPB at 1：3.     

New insert layer structure OLEDs

An insert layer structure organic electroluminescent device（OLED） based on a new luminescent material （Zn（salen）） is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn（salen）/Liq/LiF/A1/CuPc/NPD/Zn（salen）/Liq/LiF/A1. Effective insert electrode layers comprising LiF（1nm）/Al（5 nm） are used as a single semitransparent mirror, and bilayer cathode LiF（1 nm）/A1（100 nm） is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.     

Analysis of error performance on Turbo coded FDPIM

Due to variable symbol length of digital pulse interval modulation（DPIM）, it is difficult to analyze the error performances of Turbo coded DPIM. To solve this problem, a fixed-length digital pulse interval modulation（FDPIM） method is provided. The FDPIM modulation structure is introduced. The packet error rates of uncoded FDPIM are analyzed and compared with that of DPIM. Bit error rates of Turbo coded FDPIM are simulated based on three kinds of analytical models under weak turbulence channel. The results show that packet error rate of uncoded FDPIM is inferior to that of uncoded DPIM. However, FDPIM is easy to be implemented and easy to be combined, with Turbo code for soft-decision because of its fixed length. Besides, the introduction of Turbo code in this modulation can decrease the average power about 10 dBm, which means that it can improve the error performance of the system effectively.     

A method for calculating the center position of collimated light

It is a key problem to accurately calculate beam spots＇ center of measuring the warp by using a collimated laser. A new method, named double geometrical center method （DGCM）, is put forward for the first time. In this method, a plane wave perpendicularly irradiates an aperture stop, and a charge couple device （CCD） is employed to receive the diffraction-beam spots, then the geometrical centers of the fast and the second diffraction-beam spots are calculated respectively, and their mean value is regarded as the center of datum beam. In face of such adverse instances as laser intension distributing defectively, part of the image being saturated, this method can still work well. What＇s more, this method can detect whether an unacceptable error exits in the courses of image receiving, processing and calculating. The experimental results indicate the precision of this method is high.     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Preparation and Characterization of TaN ALD Precursors

High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET ＞ PDMAT ＞ TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.