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1.
    
The probing of the micromechanical properties within a two‐dimensional polymer structure with sixfold symmetry fabricated via interference lithography reveals a nonuniform spatial distribution in the elastic modulus “imprinted” with an interference pattern in work reported by Tsukruk, Thomas, and co‐workers on p. 1324. The image prepared by M. Lemieux and T. Gorishnyy shows how the interference pattern is formed by three laser beams and is transferred to the solid polymer structure. The elastic and plastic properties within a two‐dimensional polymer (SU8) structure with sixfold symmetry fabricated via interference lithography are presented. There is a nonuniform spatial distribution in the elastic modulus, with a higher elastic modulus obtained for nodes (brightest regions in the laser interference pattern) and a lower elastic modulus for beams (darkest regions in the laser interference pattern) of the photopatterned films. We suggest that such a nonuniformity and unusual plastic behavior are related to the variable material properties “imprinted” by the interference pattern.  相似文献   

2.
    
Interference lithography (IL) holds the promise of fabricating large‐area, defect‐free 3D structures on the submicrometer scale both rapidly and cheaply. A stationary spatial variation of intensity is created by the interference of two or more beams of light. The pattern that emerges out of the intensity distribution is transferred to a light sensitive medium, such as a photoresist, and after development yields a 3D bicontinuous photoresist/air structure. Importantly, by a proper choice of beam parameters one can control the geometrical elements and volume fraction of the structures. This article provides an overview of the fabrication of 3D structures via IL (e.g., the formation of interference patterns, their dependence on beam parameters and several requirements for the photoresist) and highlights some of our recent efforts in the applications of these 3D structures in photonic crystals, phononic crystals and as microframes, and for the synthesis of highly non spherical polymer particles. Our discussion concludes with perspectives on the future directions in which this technique could be pursued.  相似文献   

3.
下一代光刻技术   总被引:2,自引:0,他引:2  
介绍了下一代光刻技术的演变,重点描述了浸没式光刻技术、极端远紫外光刻技术、纳米压印光刻技术和无掩模光刻技术的基本原理、技术优势、技术难点以及研发,并展望了这几种光刻技术的前景。  相似文献   

4.
    
Two soft lithographic techniques—topographically directed photolithography (TOP) and near‐field contact‐mode photolithography—have been used to pattern spherical surfaces with features as small as 175 nm. Each technique has the ability to pattern more than a 60° arc of a spherical surface, albeit with distortions at the edge. Use as an optical polarizer demonstrates an application of these types of patterned surface.  相似文献   

5.
简述了光学光刻技术在双重图形曝光、高折射率透镜材料及浸没介质、32nm光刻现状及22nm浸没式光刻技术的进展,指出了光学光刻技术的发展趋势及进入22nm技术节点的前景。  相似文献   

6.
    
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.  相似文献   

7.
介绍了一种大面积接近、接触式光刻的新方法,通过光源步进拼接扫描提供一个高均匀度的大面积的照明光源。主要论述了小面积扫描单元的形状及步进扫描拼接原理、应用及其优点,分析了扫描面的不均匀度。  相似文献   

8.
    
Nano/microwires of semiconducting materials (e.g., GaAs and InP) with triangular cross‐sections can be fabricated by “top–down” approaches that combine lithography of high‐quality bulk wafers (using either traditional photolithography or phase‐shift optical lithography) with anisotropic chemical etching. This method gives good control over the lateral dimensions, lengths, and morphologies of free‐standing wires. The behaviors of many different resist layers and etching chemistries are presented. It is shown how wire arrays with highly ordered alignments can be transfer printed onto plastic substrates. This “top–down” approach provides a simple, effective, and versatile way of generating high‐quality single‐crystalline wires of various compound semiconductors. The resultant wires and wire arrays have potential applications in electronics, optics, optoelectronics, and sensing.  相似文献   

9.
    
The cover shows a patterned assembly of GaAs nanowires with their ends tethered to a bulk single‐crystal wafer as described on p. 30 by Rogers and co‐workers. These wires, which have triangular cross‐sections, were fabricated via a top–down process that combines photolithography and anisotropic chemical etching. Nano/microwires of semiconducting materials (e.g., GaAs and InP) with triangular cross‐sections can be fabricated by “top–down” approaches that combine lithography of high‐quality bulk wafers (using either traditional photolithography or phase‐shift optical lithography) with anisotropic chemical etching. This method gives good control over the lateral dimensions, lengths, and morphologies of free‐standing wires. The behaviors of many different resist layers and etching chemistries are presented. It is shown how wire arrays with highly ordered alignments can be transfer printed onto plastic substrates. This “top–down” approach provides a simple, effective, and versatile way of generating high‐quality single‐crystalline wires of various compound semiconductors. The resultant wires and wire arrays have potential applications in electronics, optics, optoelectronics, and sensing.  相似文献   

10.
    
Zwitter polymers are defined as polymers that undergo transformation from a linear to a crosslinked structure under electron‐beam irradiation. A resist polymer may be either linear or crosslinked, depending on electron‐beam dosage. The structural transformation of acrylic resin make it suitable for applications in positive and negative resists in the semiconductor field. The contrast ratio and threshold dose both increase with increasing resist thickness for both the positive and negative resists, while the positive resist exhibits better contrast than the negative. The intensity of the characteristic Fourier‐transform infrared absorption band at 1612 cm–1 (vinyl group) is used to explain the phenomena behind these resist transformations. We evaluate the effects of two important processing conditions: the soft baking and post‐exposure baking temperatures. Pattern resolution decreases upon increasing the baking temperature, except for soft baking of the negative resist. The effect of electron dose on the pattern resolution is also discussed in detail for both resists. High electron‐beam exposure does not improve the etching resistance of the resist because of the porous nature of the resist that develops after high‐dosage irradiation.  相似文献   

11.
针对分辨力100nm的ArF光刻机,在环形照明和四极照明下,对4种曝光图形结构光刻性能进行了仿真研究。仿真结果表明,如果光刻物镜在加工装调后的光波像差为6nm,杂散光为2%,工件台运动标准偏差为8nm,曝光量控制在10%,CD≤±10%CD,利用四级照明,可以在较大的焦深范围内(DOF≥0.4~0.5μm)实现满足器件要求的100nm密集线条、半密集线条的光刻成像。当曝光剂量更精确控制到7%,可以在较大的焦深范围内(DOF≥0.4~0.5μm)实现满足器件要求的100nm孤立线条的光刻成像。  相似文献   

12.
    
In order to modify the output characteristics of organic light‐emitting devices (OLEDs), the optical properties of an active layer within the device are patterned without introducing any thickness modulation. For this purpose a new conjugated copolymer, which serves as a hole‐transporting material and at the same time can be index patterned using UV techniques, is synthesized. Poly(VC‐co‐VBT) (VC: N‐vinylcarbazole; VBT: 4‐vinylbenzyl thiocyanate) is prepared by free‐radical copolymerization of VC and VBT. The material contains photoreactive thiocyanate groups that enable altering of the material's refractive index under UV illumination. This copolymer is employed as a patternable hole‐transporting layer in multilayer OLEDs. Refractive‐index gratings in poly(VC‐co‐VBT) are inscribed using a holographic setup based upon a Lloyd mirror configuration. The fourth harmonic of a Nd:YAG (YAG: yttrium aluminum garnet) laser (266 nm) serves as the UV source. In this way 1D photonic structures are integrated in an OLED containing AlQ3 (tris(8‐hydroxyquinoline) aluminum) as the emitting species. It is assured that only a periodical change of the refractive index (Δn = 0.006 at λ = 540 nm) is generated in the active material but no surface‐relief gratings are generated. The patterned devices show more forward‐directed out‐coupling behavior than unstructured devices (increase in luminosity by a factor of five for a perpendicular viewing direction). This effect is most likely due to Bragg scattering. For these multilayer structures, optimum outcoupling was observed for grating periods Λ ~ 390 nm.  相似文献   

13.
    
A method for fabricating chemically nanopatterned surfaces based on a combination of colloidal lithography and plasma‐ enhanced chemical vapor deposition (PECVD) is presented. This method can be applied for the creation of different nanopatterns, and it is in principle not limited in patterning resolution. Nanocraters of poly(acrylic acid) (carboxylic moieties) surrounded by a matrix of poly(ethylene glycol) are fabricated. Chemical force microscopy demonstrates that the process is able to produce the expected surface chemical contrast. Finally, the carboxylic groups of the craters are activated in order to induce the covalent binding of fluorescent‐labeled proteins. Fluorescence investigation using scanning confocal microscopy shows that the proteins are preferentially attached inside the functional craters.  相似文献   

14.
Liquid‐polymer films sandwiched between two electrodes develop a surface instability caused by the electric field, giving rise to polymer structures that span the two plates. This study investigates the development of the resulting polymer morphologies as a function of time. The initial phase of the structure formation process is a sinusoidal surface undulation, irrespective of the sample parameters. The later stages of pattern formation depend on the relative amount of polymer in the capacitor gap (filling ratio). For high enough filling ratios, the final morphology of the pattern is determined by the partial coalescence of the initial pattern. The introduction of lateral‐field heterogeneities influences the initial pattern formation, with columns nucleated at locations of highest electric field (isolated points or edges). The subsequently formed secondary columns have higher degree of lateral symmetry compared to the pattern formed in a homogeneous field. The nucleation of individual columns or plugs also dominates the pattern formation in the presence of an electrode consisting of an array of lines. The results of this study therefore allow us to draw the conclusion that the accurate replication of structured electrodes typically proceeds by the initial nucleation of individual columns, followed by a coalescence process that yields the polymer replica.  相似文献   

15.
光刻机的演变及今后发展趋势   总被引:13,自引:2,他引:13  
微电子技术的发展一直是光刻设备和技术发展与变革的动力。通过介绍光刻机的演变和所面临的挑战,揭示下一代光刻设备的发展潜力,结合比较极紫外光刻机和电子束曝光机的开发现状和特点,预言将来以极紫外光刻机、电子束曝光机和某种常规光刻机结合,来实现工业需要的各种图形的制备。  相似文献   

16.
    
This investigation deals with the synthesis and detailed study of a photoinitiator‐free photosensitive polyimide gate insulator for organic thin‐film transistors (OTFTs), one of the most important components of active‐matrix displays on plastic substrates. The photosensitive polyimide precursor poly(amic acid) is prepared from the aromatic dianhydride 3,3′,4,4′‐benzophenone tetracarboxylic dianhydride (BTDA) and the novel aromatic diamine 7‐(3,5‐diaminobenzoyloxy)coumarine (DACM). The photosensitivity of the poly(amic acid) film is investigated using a high‐pressure mercury lamp at 280–310 nm. The pattern resolution of the photocured film was about 50 μm. The surface morphology of the films before and after the photopatterning process is also investigated. In addition, we have fabricated pentacene OTFTs with the photoinitiator‐free photosensitive polyimide as gate insulator. The OTFT characteristics are discussed in more detail with respect to the electrical properties of the photosensitive polyimide thin film.  相似文献   

17.
    
A method for creating microscale‐patterned surfaces by direct‐write lithography is described. A tightly focused, low‐power infrared laser beam is applied to a homogeneous precursor solution containing soluble reagents. When the laser is focused directly at a glass–solution interface, it initiates the local precipitation of a solid product that attaches firmly to the substrate. Operating the laser momentarily forms isolated spots, whereas moving the microscope stage or the laser spot draws continuous lines. The method has been demonstrated for metallic silver and gold, for oxidized copper, and for molybdenum disulfide, suggesting a broad range of suitable materials. Silver patterns were further modified by chemical reactions. Their morphology and physical properties can be altered during deposition by the use of capping agents, which may provide an onset for further functionalization.  相似文献   

18.
    
An inorganic polymer photoresist was successfully synthesized for the first time with high photosensitivity and a high ceramic yield. Furthermore, it is shown by Kim, Yang, and co‐workers on p. 1235 that a nano‐stereolithography process linked with careful pyrolysis of this resin paves the way for the fabrication of 2D and 3D ceramic microstructures (examples of which are shown on the cover) with high spatial resolution. We report a newly synthesized inorganic polymer photoresist with a high ceramic yield by the functionalization of polyvinylsilazane (KiON VL20) with 2‐isocyanatoethyl methacrylate via linkage or insertion reaction routes. The chemistry of the synthesis and the pyrolytic conversion as well as the mechanical evaluation were investigated by using various analytical instruments. We show for the first time that this photosensitive resin is a novel precursor for the fabrication of complex 3D SiCN ceramic microstructures with a 210 nm resolution via a two‐photon absorbed crosslinking process and subsequent pyrolysis at 600 °C under a nitrogen atmosphere. Moreover, the dimensional deformation during pyrolysis was significantly reduced by adding silica nanoparticles as a filler. In particular, the ceramic microstructures containing 40 wt % silica nanoparticles exhibited a relatively isotropic shrinkage owing to its sliding free from the substrate during pyrolysis.  相似文献   

19.
    
We report a newly synthesized inorganic polymer photoresist with a high ceramic yield by the functionalization of polyvinylsilazane (KiON VL20) with 2‐isocyanatoethyl methacrylate via linkage or insertion reaction routes. The chemistry of the synthesis and the pyrolytic conversion as well as the mechanical evaluation were investigated by using various analytical instruments. We show for the first time that this photosensitive resin is a novel precursor for the fabrication of complex 3D SiCN ceramic microstructures with a 210 nm resolution via a two‐photon absorbed crosslinking process and subsequent pyrolysis at 600 °C under a nitrogen atmosphere. Moreover, the dimensional deformation during pyrolysis was significantly reduced by adding silica nanoparticles as a filler. In particular, the ceramic microstructures containing 40 wt % silica nanoparticles exhibited a relatively isotropic shrinkage owing to its sliding free from the substrate during pyrolysis.  相似文献   

20.
    
Conventional photolithography uses rigid photomasks of fused quartz and high‐purity silica glass plates covered with patterned microstructures of an opaque material. We introduce new, transparent, elastomeric molds (or stamps) of poly(dimethylsiloxane) (PDMS) that can be employed as photomasks to produce the same resist pattern as the pattern of the recessed (or non‐contact) regions of the stamps, in contrast to other reports in the literature[1] of using PDMS masks to generate edge patterns. The exposure dose of the non‐contact regions with the photoresist through the PDMS is lower than that of the contact regions. Therefore, we employ a difference in the effective exposure dose between the contact and the non‐contact regions through the PDMS stamp to generate the same pattern as the PDMS photomask. The photomasking capability of the PDMS stamps, which is similar to rigid photomasks in conventional photolithography, widens the application boundaries of soft‐contact optical lithography and makes the photolithography process and equipment very simple. This soft‐contact optical lithography process can be widely used to perform photolithography on flexible substrates, avoiding metal or resist cracks, as it uses soft, conformable, intimate contact with the photoresist without any external pressure. To this end, we demonstrate soft‐contact optical lithography on a gold‐coated PDMS substrate and utilized the patterned Au/PDMS substrate with feature sizes into the nanometer regime as a top electrode in organic light‐emitting diodes that are formed by soft‐contact lamination.  相似文献   

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