六氟丙酮及其应用

介绍了六氟丙酮的主要特性 ,用途及合成方法     

基于六氟丙酮的功能材料

在介绍六氟丙酮理化性能的基础上,对于以六氟丙酮作为最初始原料合成的功能性材料的起始物进行了介绍,并对由此起始物出发所形成的双酚AF类、6F-双酸(酐)类、一元或多元氟醇类、环氧聚合物类等各类功能材料的制备及主要性能进行了介绍和评述,最后对基于六氟丙酮的功能材料发展进行了展望.     

用改进曝光模型模拟厚胶显影轮廓

考虑厚胶曝光过程中非线性因素的影响及其显影特点,用一套随抗蚀剂厚度发生变化的曝光参数改进的Dill曝光模型,仿真厚层抗蚀剂光刻过程,并比较新曝光模型与原有Dill模型模拟的结果差异。模拟显示,用新曝光模型获得的厚抗蚀剂显影轮廓与实验结果吻合较好;并对厚胶光刻成像机理进行了讨论。通过分析正性厚层抗蚀剂AZ4562的显影轮廓,给出其显影线宽及边墙陡度随显影时间的变化规律,提出应以获得最大边墙陡度作为优化显影时间的思想。对厚度5μm和15μm的抗蚀剂,经计算,可获得良好的抗蚀剂浮雕轮廓的优化显影时间分别为98s和208s。     

Surfaces that resist bioadhesion

The search for surfaces that resist bioadhesion has continued with the pursuit of a number of avenues. A large part of the studies has investigated PEG coatings. Nevertheless, there is still controversy about what exactly the properties and modes of action of an ‘ideal’ PEG coating should be. While some studies have reported no irreversible protein adsorption, other, very similar coatings appear less able to resist bioadhesion. Of great interest are results showing that PEG surfaces with very short chains are capable of rejecting proteins. As it is very difficult to obtain direct information about the microstructure of the coatings, studies typically employ plausible models to interpret observations. New analytical techniques and the direct measurement of interfacial forces between proteins and surfaces open up the possibility of improved, guided design and feedback in the optimization of surfaces intended to resist bioadhesion.     

Ion-implanted resist removal using atomic hydrogen

We removed B-, P-, and As-ion-implanted positive-tone novolak resists with an implantation dose of 5 × 10¹² to 5 × 10¹⁵ atoms/cm² at 70 keV, using atomic hydrogen. Though the removal rate decreased with increase in the implantation dose, all of the ion-implanted resists were removed. The rates of thickness of the surface-hardened layer/all resist layer of B, P, and As implanted resists were 0.38, 0.26, and 0.16, respectively, by SEM observation. The removal rate decreased with increasing the rate of the surface-hardened layer. The energy supplied from the ions to the resist concentrated on the surface side in the increasing order of B-P-As.     

Barnacles resist removal by crack trapping

We study the mechanics of pull-off of a barnacle adhering to a thin elastic layer which is bonded to a rigid substrate. We address the case of barnacles having acorn shell geometry and hard, calcarious base plates. Pull-off is initiated by the propagation of an interface edge crack between the base plate and the layer. We compute the energy release rate of this crack as it grows along the interface using a finite element method. We also develop an approximate analytical model to interpret our numerical results and to give a closed-form expression for the energy release rate. Our result shows that the resistance of barnacles to interfacial failure arises from a crack-trapping mechanism.     

A chemically amplified fullerene-derivative molecular electron-beam resist

Current lithographic resists depend on large polymeric materials, which are starting to limit further improvements in line-width roughness and feature size. Fullerene molecular resists use much smaller molecules to avoid this problem. However, such resists have poor radiation sensitivity. Chemical amplification of a fullerene derivative using an epoxy crosslinker and a photoacid generator is demonstrated. The sensitivity of the material is increased by two orders of magnitude, and 20-nm line widths are patterned.     

A new composite designed to resist wear

Nacre is known for its superior mechanical properties due to its uniquely interlocked-layered structures. In this study, a new composite containing nacre in an Al matrix was fabricated. The composite was produced using powder metallurgy method followed by a heat treatment. Mechanical properties were tested using SEM, micro hardness tester and profilometer. Results showed that the hardness of the composites increased as the concentration of nacre increased in the composite. The hardness of a composite containing 20 wt% of nacre increased by 40% compared to pure Al. Tribological evaluation indicates that samples with 1 wt% and 5 wt% of nacre exhibited the best wear resistance. The wear mechanism changed from adhesive to abrasive wear with varying concentration of nacre. This research demonstrates that the design of mechanical properties and the control of wear mechanisms is possible through the optimization of hybrid configuration. This approach can be adapted to most conventional materials.     

Selecting aluminum alloys to resist failure by fracture mechanisms

Useful information and guidelines are presented for engineers who wish to minimize fracture problems in aluminum engineering structures through better application of materials knowledge and optimum alloy choice. Consideration is given to methods and examples of characterizing fracture resistance of aluminum alloys including interpretations of data addressing basic design approaches. Specific attention is given to trade-offs among properties of strength, fracture toughness, corrosion, stress corrosion cracking, and fatigue in structural aluminum materials.     

Graphene resist interlacing process for versatile fabrication of free-standing graphene

We present a graphene resist interlacing process (GRIP) to sandwich graphene between polymer lines in a cloth-like fashion, making it more accessible for experiments and applications. We demonstrate the handling of large-area graphene in this way. Here, GRIP is used to fabricate supports for transmission electron microscopy. These supports improve the imaging quality of nanoparticles, as we show by comparison to imaging on standard lacey carbon supports.     

Optimization of rock/polymer composites to resist projectile penetration

Composites cast from polyurethane resins, rock aggregates and sand have been examined to determine their resistance to penetration by high velocity projectiles. The effects of using different polymer and rock types have been investigated, and the resultant composite mixes have been optimized using response surface theory to obtain a protective material to clad buildings rapidly and economically. Variables considered in the mix optimization were % polymer, % aggregate, aggregate particle size, and polymer hardness. Penetration tests were carried out on the optimized composites to determine the thickness required for a given confidence level of projectile containment.     

FT-IR study of a chemically amplified resist for X-ray lithography

Microelectronic devices for future applications demand lithographic performance that falls within the 0.10 microm region and below. Chemically amplified resists (CARs), such as the positive tone commercial UVIII resist, offer a substantial gain in sensitivity, resolution, and process efficiency in deep ultraviolet, e-beam, and X-ray lithographies. In this work, the UVIII resist is characterized for X-ray lithographic applications by studying the "deprotection" or acid generation-diffusion process of the resist under different conditions of post-exposure bake (PEB) temperature and time, and of X-ray exposure dose. The X-ray irradiation from a copper anode at a wavelength of 1.33 nm was at an intensity of 30 microW/cm2 on the resist surface. The deprotection process of the resist during PEB was accurately monitored by using Fourier transform infrared (FT-IR) spectroscopy. The infrared absorption peaks at 1151, 1369, and 2977 cm(-1) in the spectrum of the UVIII resist were found to be useful indicators for the completion of deprotection. Results of the experiments showed that the performance of UVIII could be optimized at the PEB temperature of 140 degrees C, a time of 2 min, and X-ray exposure dose of 12 mJ/cm2. The change in resist thickness after PEB was also measured. The results were confirmed by scanning electron microscopy (SEM) in which a test structure as small as 0.12 microm was obtained in a 1-microm-thick UVIII resist layer.