LiNbO_3的反应离子刻蚀

介绍了在含有CCl_2F_2,CF_4,O_2和Ar的混合气体中的LiNbO_3反应离子刻蚀。讨论了总压强为1—10微米时强气体组分和压强的影响。它有可能在控制刻蚀剖面的情况下复制精细图案(～2000埃),所以可望用来制作电光和声光器件中LiNbO_3上的三维图案。     

紫外激光刻蚀位相光栅实验初步研究

描述308nm和193nm波长准分子激光对PI、PC和PMMA三种聚合物的微刻蚀实验,并从刻蚀表面光洁度、边缘锐利和垂直度、刻蚀阈值等方面对刻蚀特性进行了讨论和比较.其中308nm激光对PC和PMMA刻蚀性能很差,而193nm激光刻蚀PI和PC,以及308nm激光刻蚀PI都能达到微米级横向分辨率和亚微米级深度精度,通过这种方法成功地刻蚀出了二阶位相光栅.     

一种新的亚微米制造技术

已经研制成功一种制作亚微米线宽和器件的新技术。此技术不需要电子束或其它外加的刻蚀技术,而只用常规光刻法和一次边缘选择镀工序。在此工序中,把金属镀到已刻图案的金属层的边缘上。然后,此已镀边缘作为下步等离子腐蚀的掩模,以腐蚀其下层的导体或介质。此技术作出的线宽小至0.04微米,并能用来制造多种微波器件。特别是已用它来制作栅长为0.1微米的镀金铬栅 GaAsMESFET。此法所得 GaAsMESFET 的性能,比得上用比较复杂和花费大的制作栅图案技术制造出来的器件。譬如,在离子注入的 GaAs 上制作的5微米源-漏间距,0.3微米栅长和250微米栅宽的 MESFET,12千兆赫下最大可用增益超过10分贝。     

低功率连续CO2激光诱导玻璃表面微纳结构及对其光学性能的改善

超白玻璃是一种超透明低铁钙钠玻璃,具有优越的机械、物理和光学性能,被广泛应用于制作各种光学元件以及仪器保护装置,特别是硅太阳能电池表面的封装.应用低功率连续CO2激光器在不同工艺参数条件下,对超白玻璃表面进行刻蚀诱导,通过分光光度计测量这种结构对紫外、可见光、近红外(250～1500nm)不同波段的吸收和透过率,并研究激光刻蚀参数与透过率的关系.实验表明,激光刻蚀诱导产生了微米量级的表面形貌结构,这种结构改变了材料在可见光380nm到近红外波段的光谱透过率特性.     

基于软刻蚀技术的微三维结构加工方法研究

软刻蚀是通过表面带有图案的弹性模板来实现图案转移的图形复制技术,弹性印章是软刻蚀技术的核心。简单介绍了软刻蚀技术,使用SDS-3型电子束曝光机,采用重复增量扫描方式进行曝光,生成弹性印章的母版,将其硅烷化后用以制作弹性印章,再利用软刻蚀技术可进行微图形的复制,得到微三维结构。显影后得到轮廓清晰的三维结构,证明将电子束重复增量扫描曝光方式与软刻蚀技术相结合可为制作微三维结构提供一种简单、有效的低成本途径。     

用SF_6-N_2混合气的反应离子刻蚀制作WSi_x微米结构

本文报道了ESi_x在SF_6-Ar、SF_6-N_2混合气中的反应离子刻蚀(RIE)的实验结果。研究了在SF_6-N_2的混合气中刻蚀WSi_x时,气体成分、气体流量、工作气压和输入功率对刻蚀速率的影响。发现在SF_6/N_2中刻蚀WSi_x微米结构具有优越性。实验结果的重复性较好,并在高速场效应器件、光电集成器件(微米结构)制作中得到应用。     

100%填充因子的硅微透镜阵列的制作

本文成功制作出了表面光滑且具有100%填充因子的硅微阵列阵列结构。制作流程包括：旋涂光刻胶,热熔融和反应离子可是转移。首先,在硅衬底上旋涂SU-8光刻胶,并光刻显影;其次,热熔融和热处理光刻胶阵列得到光刻胶微透镜阵列;最后,反应离子刻蚀转移形成硅微透镜阵列。实验表明,通过调节反应离子刻蚀气体SF6和O2的量分别到60sccm和50sccm,就可以得到无间距的硅微透镜阵列。在此种情况下,光刻胶和硅衬底的刻蚀速率比值为1:1.44。单个微透镜底端尺寸为30.1微米,高度为3微米,焦距在15.4微米到16.6微米之间。     

硅基PZT薄膜的制备与刻蚀工艺研究

采用溶胶－凝胶（Sol-Gel）法制备了PZT薄膜,在600℃的退火温度下即获得了晶化完善的钙然矿铁电相结构。采用典型的半导体光刻工艺,利用HCl/HF刻蚀溶液成功地获得刻蚀线条分辨率达微米量级的PZT薄膜微图形。较好的解决了有关PZT薄膜制备与加工中存在的关键问题,为硅基铁电薄膜器件的实现奠定了良好的工艺基础。     

宽离子束刻蚀微透镜阵列研究

本文对宽束离子束刻蚀技术进行了研究，并运用宽离子束对微透镜阵列进行了刻蚀，表明宽离子束可进行微米、亚微米刻蚀。     

铁电刻蚀的研究进展

铁电刻蚀是一种新颖的刻蚀技术,在铁电研究领域日益受到重视。对铁电刻蚀的研究现状进行了综述。首先介绍了铁电极化对铁电材料表面性能的影响,然后详细阐述了铁电畴图形化的三种方法,即微电极图形化、扫描探针图形化和电子束图形化,并分析了它们的图形化机制和特点。其中微电极方法的铁电畴图形的最小尺寸为微米量级,而扫描探针和电子束方法的铁电畴图形的最小尺寸可小于100nm。与铁电畴定位的表面反应相结合,铁电刻蚀可为纳米结构的制造提供新的途径,因此在纳米器件领域具有广泛的应用前景。未来铁电刻蚀技术发展的方向是在改进铁电刻蚀技术的同时推进其在纳米器件制造中的应用。     

Coding Cell Micropatterns Through Peptide Inkjet Printing for Arbitrary Biomineralized Architectures

Well‐designed micropatterns present in native tissues and organs involve changes in extracellular matrix compositions, cell types and mechanical properties to reflect complex biological functions. However, the design and fabrication of these micropatterns in vitro to meet task‐specific biomedical applications remains a challenge. A de novo design strategy to code and synthesize functional micropatterns is presented to engineer cell alignment through the integration of aqueous‐peptide inkjet printing and site‐specific biomineralization. The inkjet printing provides direct writing of macroscopic biosilica selective peptide‐R5 patterns with micrometer‐scale resolution on the surface of a biopolymer (silk) hydrogel. This is combined with in situ biomineralization of the R5 peptide for site‐specific growth of silica nanoparticles on the micropatterns, avoiding the use of harsh chemicals or complex processing. The functional micropatterned systems are used to align human mesenchymal stem cells and bovine serum albumin. This combination of peptide printing and site‐specific biomineralization provides a new route for developing cost‐effective micropatterns, with implications for broader materials designs.     

Directing Osteogenesis of Stem Cells with Drug‐Laden,Polymer‐Microsphere‐Based Micropatterns Generated by Teflon Microfluidic Chips

Human bone tissue is built in a hierarchical way by assembling various cells of specific functions; the behaviors of these cells in vivo are sophisticatedly regulated. However, the cells in an injured bone caused by tumor or other bone‐related diseases cannot properly perform self‐regulation behaviors, such as specialized differentiation. To address this challenge, a simple one‐step strategy for patterning drug‐laden poly(lactic‐co‐glycolic acid) (PLGA) microspheres into grooves by Teflon chips is developed to direct cellular alignment and osteogenic commitment of adipose‐derived stem cells (ADSCs) for bone regeneration. A hydrophilic model protein and a hydrophobic model drug are encapsulated into microsphere‐based grooved micropatterns to investigate the release of the molecules from the PLGA matrix. Both types of molecules show a sustained release with a small initial burst during the first couple of days. Osteogenic differentiated factors are also encapsulated in the micropatterns and the effect of these factors on inducing the osteogenic differentiation of ADSCs is studied. The ADSCs on the drug‐laden micropatterns show stronger osteogenic commitment in culture than those on flat PLGA film or on drug‐free grooved micropatterns cultured under the same conditions. The results demonstrate that a combination of chemical and topographical cues is more effective to direct the osteogenic commitment of stem cells than either is alone. The microsphere‐based groove micropatterns show potential for stem cell research and bone regenerative therapies.     

Direct Writing Micropatterns with a Resolution up to 1 µm

Solution processes have been widely used to fabricate micropatterned surfaces for its mild operation conditions. However, current approaches suffer from limitations of either low resolution or high cost. Here, a facile approach is proposed for direct writing micropatterns with a resolution up to ≈ 1 µm using a unit of triple conical fibers with the side‐by‐side parallel arrangement. With this unit, the resolution of the micropatterns can be mainly controlled by the single central conical fiber, with one side of the fiber facilitating continuous and steady liquid transfer onto the substrate and the other side mechanically supporting the whole unit. Particularly, the unit enables tunable dimension of the micropatterns within a rather large scale from ≈ 1 µm to ≈ 1.3 mm by varying the writing parameters (speed, height, and angle). Moreover, the unit is applicable for direct patterning various liquids, even into microline arrays, with a high resolution. It enables direct writing conductive microline with a width of ≈ 1 µm in a centimeter length scale, which can be used for constructing microcircuits. It is envisioned that the result offers a new perspective for preparing high‐resolution micropatterns using solution processes.     

基于光子晶体光纤飞秒激光放大器的微纳加工系统

以掺镱大模面积光子晶体光纤(PCF)飞秒激光放大器为光源组建了一套结构紧凑且运行稳定的飞秒激光微纳加工系统,中心波长为1040 nm,重复频率50 MHz,最大平均功率16 W,光栅压缩后脉冲宽度85 fs。利用该套系统在硅片、金属薄膜(Cr膜、Al膜)上演示了微图案的刻划,并与采用重复频率1 kHz的固体钛宝石飞秒激光放大器的加工结果进行对比,发现利用新组建的加工系统进行微纳加工,由于单脉冲能量较小且便于调节,使得刻划微图案时边缘加工效果更容易控制,且避免了加工过程中未加工区域受到的污染,保护了制作衬底。显示了该套系统高重复频率和高平均功率的特性及其在改善微纳加工效果及明显提高加工效率方面的优势。     

Designing Multicolor Micropatterns of Inverse Opals with Photonic Bandgap and Surface Plasmon Resonance

Structural coloration provides unique features over chemical coloration, such as nonfading, color tunability, and high color brightness, rendering it useful in various optical applications. To develop the structural colors, two different mechanisms of coloration–photonic bandgap (PBG) and surface plasmon resonance (SPR)–have been separately utilized. In this work, a new method is suggested to create structurally colored micropatterns by regioselectively employing SPR in a single film of inverse opal with PBG. The inverse opals are prepared by thermal embedding of opal into a negative photoresist and its subsequent removal. The inverse opals have a hexagonal array of open pores on the surface which serves as a template to make SPR‐active nanostructures through a directional deposition of gold, a perforated gold film and an array of curved gold disks are formed. With a shadow mask lithographically prepared, the gold is regioselectively deposited on the surface of the inverse opal, which results in two distinct regions of gold‐free inverse opal with PBG and gold nanostructure with SPR. As PBG and SPR develop their own structural colors respectively, the resultant micropatterns exhibit pronounced dual colors. More importantly, the micropatterns show the distinguished optical response for evaporation of volatile liquids that occupy the pores.     

Enhanced Light Harvesting in Mesoscopic Solar Cells by Multilevel Multiscale Patterned Photoelectrodes with Superpositioned Optical Properties

Investigations on nano‐ and micropatterns have been intensively performed in optical applications due to their light modulation effects for enhanced photon utilization. Recently, incorporation of periodic architectures in solar cells have brought significant enhancements in light harvesting and energy conversion efficiency, however, further improvements in performance are required for practical applications due to the intrinsic limitations of single‐level patterns. Herein, this study reports mesoscopic solar cells employing photoelectrodes with multilevel multiscale patterns. Polydimethylsiloxane film with multilevel nano/micropatterns (integrated in z‐axis direction) is prepared by LEGO‐like multiplex lithography, and its architecture is imprinted on mesoporous TiO₂ electrode by soft molding technique. By various spectral analyses and simulations, advanced light harvesting properties by superposition of optical responses from constituent nano‐ and micropatterns are verified. The effectiveness of the strategy is confirmed by applications in dye‐sensitized solar cells as a model system, wherein over 17.5% increase in efficiency (by multilevel 400 nm line/20 μm dot structures) is observed. Also, external quantum efficiencies clearly exhibit that the improved light harvesting originates from the combined effects of diffraction grating and random scattering induced by both nano‐ and microarchitectures, respectively. Moreover, the validity of the multiscale approach in different dimensions is also confirmed in order to demonstrate the general advantages.     

Red–Yellow Fluorescence Patterning of a Polymer Film Containing Phthalimido Carbamate Groups

Bicolor fluorescent micro‐patterns in the polymer film are prepared through the use of a new group of photobase generator containing phthalimido carbamate groups. The photobase generation from phthalimide carbamates is studied by examining the changes in pH, fluorescence intensity, and photo‐crosslinking of poly(glycidyl methacrylate). The product analysis of a model compound indicates that amine groups are produced from the photolytic cleavage of the C–N bond of the phthalimide carbamate groups. A copolymer containing phthalimide carbamate groups is applied to a bicolor fluorescent imaging material. Red‐yellow fluorescent micropatterns are obtained by treating the copolymer film, which is irradiated with 254 nm UV light through a photomask, with fluorescamine and rhodamine, consecutively. Various colored fluorescent micropatterns – green, red, or red‐yellow, are obtained on a single polymer film by varying the excitation wavelength.     

Maskless metal patterning by meniscus-confined electrochemical etching and its application in organic field-effect transistors

Conductive micropatterns is an essential part for operation of electronic devices in both industrial and academic fields. Conventional mask-based photolithography and vacuum deposition are inadequate to meet the demands of convenience and simplicity due to their complicated operation, costly instrumentations and relatively low resolution (for vacuum deposition). Development of simple and efficient mask-less fabrication techniques of conductive micropatterns is highly expected. Here we report a facile meniscus-confined electrochemical etching (MCEE) approach to fabricate metal micropatterns with resolution down to at least 1.0 μm. Both the applied bias and the moving velocity directly influence the patterning resolution. MCEE process is developed to fabricate source and drain electrodes in organic transistors on both rigid and flexible substrates. Being a maskless direct writing method, the width and morphology of the etched channel can be easily modulated by the bias and the velocity. The organic transistor with top-contact configuration presents better electrical performance with device on/off ratio of 1.1 × 10⁵ and maximum carrier mobility of 1.07 cm²V⁻¹s⁻¹, which implies that MCEE operation doesn't result in the degradation of the already deposited semiconducting film. This mask-less MCEE approach provides a potential complementary to conventional mask-based techniques for the fabrication of microscale metal patterns.     

Fabrication and Characterization of Stable Ultrathin Film Micropatterns Containing CdS Nanoparticles

Stable, ultrathin micropatterns containing CdS nanoparticles (CdS‐NPs) were fabricated in a two‐step process. In the first step, a precursor film was built‐up by the layer‐by‐layer electrostatic self‐assembly of photosensitive nitro‐diazoresin and mercaptoacetic acid capped CdS nanoparticles. In the second step, the film was selectively exposed to UV light through a photomask and developed in an aqueous solution of sodium dodecylsulfate (SDS). The formation of covalently linked micropatterns was based on the different solubilities of the irradiated and non‐irradiated parts of the film in the developer. Namely, the irradiated regions were cross‐linked and insoluble, whereas the non‐irradiated regions, linked with ionic bonds, were removed by the SDS solution. The resultant patterns were systematically characterized with atomic force microscopy, field emission scanning electron microscopy, optical microscopy, and X‐ray photoelectron spectroscopy.     

Fabrication of damage free micropatterns in silicon

A simple technique is reported for engraving damage free micropatterns in silicon. A pattern is written in PMMA by electron-beam lithography. Local oxidation and chemical etching are used to transfer the pattern into silicon.