高分子纳米LB膜的制备及其光刻性能研究

合成并表征了N-十六烷基丙烯酰胺（HDA）和对叔丁基苯酚甲基丙烯酸酯（BPhMA）的共聚物p（HDA-BPhMA）s。当HDA含量较高时，共聚物可在气，液界面上形成稳定，排列紧密的单分子薄膜，并可以Y型膜的方式沉积在各种固体基片上，形成多层均匀的Langrnuir-Blodgett（LB）膜。这种LB膜被成功地应用于光刻，获得了分辨率为0.5μm的LB膜图形。以该图形为抗蚀层，可将图形进一步转移至金属薄膜上，得到分辨率较高的金属图形，在图形转移的过程中，这种LB膜显示出较高的抗蚀性，有望作为纳米抗蚀薄膜材料在亚微米刻蚀领域得到应用。     

RF-PECVD制备类金刚石膜的研究

采用RF-PECVD法在锗(Ge)基片上沉积类金刚石(DLC)薄膜,研究了气体流量和气压对沉积区域均匀性的影响,以及基片厚度与沉积时间的关系。用拉曼光谱(Raman)分析DLC膜的结构组成,用傅立叶红外光谱仪(IR)对DLC膜的透过率进行了测量。结果表明,在气体流量为50 sccm,气压为10 Pa,功率800 W条件下薄膜厚度均匀性可达2.1%,极值透过率达62%。     

LB技术制备二棕榈酰磷脂酰胆碱分子有序膜的结构及摩擦学性能研究

通过LB技术,在处理为亲水的单晶硅表面成功制备了二棕榈酸磷脂酰胆碱（DPPC）LB分子有序薄膜。通过原子力显微镜（AFM）、摩擦磨损试验机（UMT-2）、扫描电子显微镜（SEM）对所制得薄膜进行表面形貌结构表征以及微观、宏观摩擦学性能考察。结果表明,无论单层还是十三层,DPPCLB膜均表现出远远优于花生酸（AA）LB膜的摩擦学性能,其摩擦因数为0.08～0.09（3N载荷下）,远低于空硅片摩擦因数（～0.6）;并且具有极佳的耐磨性（0.5N载荷下,耐磨寿命长达10万次以上）。分析认为,DPPCLB膜优异的摩擦学性能与DPPC分子的两个亲水极性基团有关,它可使DPPC分子与亲水基底结合得更为牢固,良好的成膜性能导致薄膜更为平整,因此具有优异的摩擦学性能。     

功率和温度对a-C:F:H膜表面形貌和结构的影响

分析薄膜的表面形貌对其生长机理和光学性质研究有着十分重要的作用。本文使用CF4和CH4为源气体，利用射频等离子体增强化学气相沉积（RF—PECVD）法在不同射频功率和沉积温度下制备了掺氟氢化无定形碳（a—C：F：H）薄膜，并在N2气氛中进行了不同温度的退火处理。用原子力显微镜（AFM）和扫描电子显微镜（SEM）观察了薄膜表面形貌，发现低功率下沉积的薄膜表面均匀性好、缺陷少；在低温下沉积的薄膜表面光滑，而高温下粗糙；真空低温退火可使薄膜表面形貌得到改善，但薄膜内空洞增加，退火温度过高，薄膜的结构发生变化，且在薄膜表面发生皲裂现象。用Raman光谱对薄膜内的结构变化进行了进一步的分析。     

聚电解质自组装膜对聚吡咯原位沉积的影响

采用聚电解质自组装膜对其体材料进行表面化学改性，通过原位聚合在基体材料上沉积聚吡咯薄膜。采用UV－Vis和SEM对聚吡咯薄膜的结构进行了表征，结果表明基体材料经聚电解质自组装膜处理后，能改变聚吡咯薄膜的结构与性能。其中聚苯乙烯磺酸钠自组装膜不仅能明显增加聚吡咯薄膜厚度和改善薄膜均匀性及其与基体材料的附着力，而且能明显改变聚吡咯薄膜的微观结构，提高其导电性。     

偏压对阴极电弧离子镀AIN薄膜的影响

在不同基体负偏压作用下,用阴极电弧离子镀等离子体物理气相沉积（PVD）方法在单晶Si(100）基片上获得六方晶系的晶态AIN薄膜。用X射线衍射仪分析了沉积膜的物相组成和晶格位向随偏压的变化。在扫描电子显微镜（SEM）下观察沉积膜的显微组织形貌。结果表明,在较小偏压下,AIN膜呈（002）择优取向,表面致密均匀;在较大偏压下,AIN膜呈（100）择优取向,表面形貌则粗糙不平,AIN薄膜的择优取向及表面形貌受到不同偏压下不同离子轰击能量的影响。     

脉冲偏压下沉积的立方氮化硼膜的断面结构研究

采用自行研制的磁增强活性反应离子镀系统，在脉冲偏压条件下成功地合成了高品质立方氮化硼（c-BN）薄膜。用傅立叶变换红外谱（FTIR）分析沉积膜的相结构，用透射电镜（TEM）及高分辨率透射电镜（HRTEM）分析膜的断面结构。FTIR结果表明：c-BN的纯度强烈地受基片负偏压 的影响，当基片负偏压为155V，c-BN膜的纯度高达90%以上，TEM及HRTEM对膜的断面结构分析表明，在膜与基片的界面处存在很薄的非晶氮化硼和六万氮化硼（h-BN）层，h-BN（0002）晶面垂直于基片段面，在界面层之上生长着单相c-BN层。     

胆甾醇辛酸酯超薄膜的制备及其热旋光性能研究

采用Langmuir-Blodgett(LB)技术制备了胆甾醇辛酸酯超薄膜,并且得出了最佳的制膜条件。在溶液质量浓度为3mg/mL,表面压为55mN/m,拉膜方式为垂直提拉法,LB膜类型为Y型膜,拉膜速度为1mm/min时,得到了形貌致密均匀的胆甾醇辛酸酯超薄膜。利用原子力显微镜(AFM)和旋光测试系统对制备的超薄膜进行研究,测试了胆甾醇辛酸酯超薄膜的热光性能。结果表明,所制备的胆甾醇辛酸酯超薄膜具有良好的热旋光性能。     

四方相BaTiO3薄膜的自组装制备与表征

以(NH₄)₂TiF₆、 Ba(NO₃)₂ 和H₃BO₃为主要原料, 采用自组装单层膜(SAMs)技术, 以三氯十八烷基硅烷(octadecyl-trichloro-silane, OTS)为模版, 在玻璃基片上制备了四方相钛酸钡晶态薄膜. 改性基板的亲水性测定与原子力显微镜（AFM）测试表明, 紫外光照射使基板由疏水转变为亲水, 能够对OTS-SAM起到修饰作用. 金相显微镜观察结果显示,OTS单分子膜指导沉积的薄膜样品表面均匀, 表明OTS SAM对钛酸钡薄膜的沉积具有诱导作用; X射线衍射（XRD）与扫描电镜（SEM）表征显示, 空气中600℃下保温2h实现了薄膜由非晶态向四方相BaTiO₃晶态薄膜的转化过程, 制备的钛酸钡薄膜在基板表面呈纳米线状生长, 线长约在500～1000nm之间, 相互连接的晶粒大小约为100nm. 文章同时对自组装单层膜和钛酸钡薄膜的形成机理进行了探讨.     

用IBAD方法合成ZrN/W纳米多层膜

本文利用高真空离子束辅助沉积系统（IBAD）在室温下制备具有纳米尺寸的ZrN／W多层膜，通过改变双靶的沉积时间，合成一系列的具有不同调制周期（3nm～10nm）的纳米多层膜。利用AES，XRD和纳米力学测试系统，表面形貌仪表征了薄膜的成分、结构和机械性能，分析了不同调制周期对薄膜结构与机械性能的影响。结果表明：多层膜的机械性能普遍优于两种个体材料的混合相；在调制周期为8．6nm时，显示出强的ZrN（111），W（110）织构和较弱的ZrN（220）峰，与其他条件下制备的样品比较，它具有较高的硬度（～26GPa），较高的弹性模量（-310GPa）和较强的膜基结合力（～80mN）。低角度XRD分析证明了薄膜的多层结构。     

A trough with radial compression for studies of monolayers and fabrication of Langmuir-Blodgett films

A new type of Langmuir trough with radial compression is reported for studies of monolayer properties and fabrication of Langmuir-Blodgett (LB) films. The trough included twenty curved diaphragms, which form a circular shape on water and compress monolayers. Typical monolayers of arachidic acid, DL--phosphatidylcholine dipalmitoyl, cellulose tridecanoate, and poly (butyl methacrylate) showed reproducible surface pressure-area isotherms with radial compression. Flow profiles were studied of monolayers on cellulose tridecanoate and poly(butyl methacrylate) and suggested that the monolayers are radially compressed with no particular film disturbance. A Wilhelmy glass plate preserved no deflection in the subphase surface from low to high surface pressures during the film compression and decompression; no pressure excess causing the deflection, which is frequently observed in the case of the film compression with a sliding barrier, was found on both sides of the Wilhelmy plate. Application of the radial compression enabled to do a symmetrical deposition for the fabrication of LB films.     

Surface characterization of the monolayer and Langmuir–Blodgett films of tetra-tert-butyl-copper phthalocyanine

The relaxation and hysteresis phenomena of the tetra-tert-butyl-copper phthalocyanine (ttb-CuPc) monolayer were investigated. The monolayer was then transferred to a hydrophilic glass surface to prepare one monolayer of Langmuir–Blodgett (LB) films. The uniformity, stability and molecular arrangement of the LB films were studied by measurements of dynamic contact angle (DCA), and were compared with the information obtained by transmission electron microscopy (TEM) and atomic force microscopy (AFM). The results show that the monolayer of ttb-CuPc is generally stable. The limiting area of a molecule is smaller than those reported in the literature, which is attributed to the aggregation of ttb-CuPc molecules into multilayer domains. The advancing and receding contact angles of water on these LB films are much smaller than those on a homogeneous film prepared by vacuum deposition. The wettability analysis on the LB films suggests that ttb-CuPc molecules are not arranged uniformly and continuously, and the LB film of ttb-CuPc contains a high ratio of exposed glass substrate. The surface morphology inspected by TEM and AFM shows the formation of separated domains of ttb-CuPc molecules, which is consistent with the surface condition evaluated from the surface wettability.     

Chemical vapor phase polymerization deposition of layer-ordered conducting polymer nanostructure for hole injection layer

Layer-ordered and ultrathin films of conducting polymer poly(3,4-ethylene dioxythiophene) (PEDOT) was prepared through a chemical vapor phase polymerization method. The chemical polymerization of 3, 4-ethylenedioxythiophene monomer was initiated in as-prepared oxidant LB films,and PEDOT nanofilms with layer-ordered structure was constructed. UV-Vis absorption spectrum and Fourier transform infrared spectroscopy was used to confirm an interface polymerization of PEDOT in as-prepared LB films. The results of X-ray diffraction and secondary ion mass spectrometry revealed that conductive PEDOT ultrathin layers were well located at different planes of LB films. The film deposition surface pressure and chemical polymerization time of PEDOT monomer in as-prepared LB films showed distinct influence on surface morphology and conductive performance of the polymerized PEDOT LB films. This layer-ordered conducting polymer ultrathin films was deposited on ITO surface as hole injection layer for organic light-emitting diodes, and the luminescence performance of devices was improved as well.     

An indigenously developed electronic control system for Langmuir-Blodgett film deposition set-up

An indigenous and simple electronic control system for Langmuir-Blodgett (LB) film deposition set-up has been developed. This set-up consists of a microstepping circuit to drive the stepper motors with precision and smooth motion, essential for controlled movement of the barriers and substrate in the LB set-up. Linear variable differential transformer (LVDT)-based displacement measuring device has been developed and used to measure the surface pressure of the monolayer material spread on the water surface. A control program is written which incorporates all operational modes required to drive the set-up and to acquire the datain situ using a set of user-friendly commands. This control set-up has been successfully used to plot the pressure-area isotherm of various amphiphilic compounds such as ferric stearate, zinc arachidate etc. and for deposition of ordered LB films of ferric stearate.     

Molecular film technology for biosensors

Two different molecular film technologies have been developed for fabricating biosensors. Firstly, bovine serum albumin spread on the air-water interface was cross-linked and transferred onto the glass surface, on which various molecular assemblies were formed by the bioaffinity technique. Secondly, a protein monolayer was adsorbed from an aqueous phase on the potential-controlled electrode surface, which was followed by electrochemical polymerization and deposition of pyrrole between the protein molecules to make the adsorbed protein film conductive.

A unique optical biosensor for taste has been fabricated by depositing fluorophore-containing Langmuir-Blodgett (LB) films on the glass surface. Each layer of the LB films exhibits its characteristic fluorescence peak which is quenched or enhanced in contact with taste substances. The sensor consisted of three different LB films containing pyrene and anthracene and deposited on a glass plate. Novel performance was demonstrated with the response of the sensor to glutamate and nucleotide umami substances.     

Structural characterization and photocatalytic activity of ultrathin TiO2 films fabricated by Langmuir-Blodgett technique with octadecylamine

TiO₂ thin films with nanometer-scale thicknesses were prepared by the hydrolysis of titanium potassium oxalate using octadecylamine (ODA) Langmuir-Blodgett (LB) films as templates. After optimizing conditions in immersion process, the amount of TiO₂ generated in the ODA LB film was found to be precisely controlled by the number of deposited ODA layers. Morphological measurements showed that uniform TiO₂ film with surface roughness of less than 1.3 nm could be prepared from the monolayer LB films through subsequent heat-treatment process, while generation of cracks became less noticeable on the 5-layer film after heat-treatment at lower holding temperature with slow heating rate. In addition, photocatalytic activities of the TiO₂ films were examined from the decomposition of cadmium stearate (CdSt) LB films and stearic acid (SA) cast films for different time intervals of irradiation with UV light. Atomic force microscopy measurements showed that an almost flat surface of the CdSt LB film changes to a moth-eaten appearance as a result of decomposition under UV light irradiation. Furthermore, the post-heat-treatment at higher temperatures resulted in decreased photocatalytic activity of the TiO₂ film for the decomposition of SA cast film.     

Polymerizabilities of amphiphilic monomers with controlled arrangements in Langmuir-Blodgett films

Polymerization of amphiphilic monomer Langmuir-Blodgett (LB) films, such as long-chain derivatives of -amino acids and diynoic, trienoic and acrylic acids, was studied. Multilayers of these monomers were prepared on CaF₂ or quartz plates by the LB method under various conditions, and polymerization processes were followed by IR and UV spectroscopy. The polycondensation of dioctadecyl- - glutamate proceeded easily in LB films at ordinary temperatures below the melting point without any initiation. All-trans- and 9-cis-9,11,13-octadecatrienoic acids polymerized very rapidly in LB films on UV irradiation. Photopolymerization in LB films of 10,12-tricosadiynoic acid was influenced by the deposition modes and annealing, and that of octadecyl acrylate was accelerated by the addition of the long- chain vinyl ether. In any case, polymerization reactions are markedly enhanced by a well-controlled arrangement of the monomer molecules in the LB films.     

Stable Langmuir-Blodgett film deposition of polyaniline and arachidic acid

An experimental study was carried out to examine the stable Langmuir-Blodgett (LB) film deposition of mixtures of polyaniline (PA) and arachidic acid (AA) at different concentration ratios, with the aim of developing a systematic methodology for the production of quality PA/AA film at the highest deposition speed. The quality of LB film was examined before, during and after the film deposition process. Images of the PA/AA composite materials at air-liquid interface, based on the Brewster angle microscopy, revealed that a 50/50 concentration ratio of PA/AA composite layer produced the best LB film structure. The feasibility of LB film deposition was determined from dynamic contact angles which were measured by a flow visualization technique. The quality of the deposited film was judged by the transfer ratio and the atomic force microscopy images. The effect of pH was also examined, and it was found that the LB film deposition for the PA/AA system could only be carried out in a narrow range of pH. It was found that the deposited LB film of the PA/AA system had a high transfer ratio and improved surface roughness at the deposition speed 30 mm/min. This deposition speed is much higher than those previously reported.     

Stability of dimethyldioctadecylammonium bromide Langmuir-Blodgett films on mica in aqueous salt solutions—implications for surface force measurements

Langmuir-Blodgett (LB) monolayer films of dimethyldioctadecylammonium bromide (DDOA) on muscovite mica have been studied using Wilhelmy plate type wetting measurements, surface force measurements, atomic force microscopy (AFM), and Brewster angle microscopy (BAM) on insoluble monolayers of DDOA before deposition. In particular, the effect of exposure to aqueous KBr salt solutions was investigated. BAM shows a heterogeneous monolayer with small condensed domains of dendritic shape under conditions normally used for deposition. A stick-jump behaviour of the meniscus is seen during deposition, leading to a large-scale heterogeneity measurable in wetting studies. These also show breakdown and hydrophilization of the LB film at the three-phase contact line (meniscus) and when exposed to salt solutions of approximately 10⁻² M concentration. The advancing contact angle against water is approximately 105°. Surface force measurements show long-range attraction in water, but also a surface charge which depends on salt concentration, and breakdown when surfaces are brought into contact in high salt concentrations. AFM images of untreated films show small holes, and breakdown when exposed to salt solution, especially at the three-phase line. The LB film is judged to be less suitable as a model hydrophobic surface owing to its heterogeneity and instability in salt solution.     

Layer by layer composite film of dimyristoyl-phosphatidylcoline and bacteriorhodopsin fabricated by multilayer molecular thin film method using fatty acid and lipid

A composite film of dimyristoyl-phosphatidylcoline (DMPC) and bacteriorhodopsin (BR) was fabricated by multilayer molecular thin film method using fatty acid and lipid on a quartz substrate or a hydrogenated amorphous silicon thin film. FTIR reflection absorption spectrums and UV absorption spectrums of the films were characterized on the detail of surface structure of the films. The spectroscopic data exhibited a specific layer by layer interaction of BR and environmental molecule DMPC above fatty acid. Especially, 4 layer composite LB films DMPC and BR exhibited an entirely different feature of IR reflection absorption spectrum depend on fatty acid species.