Polymeric silicon-containing resist materials

Silicon-containing bilayer and trilayer photoresist technology is reviewed. Multilayer resist processes of this type rely on pattern generation in a thin imaging layer followed by pattern transfer to the thick planarising underlayer by oxygen reactive ion etching (RIE). The review concentrates on materials in which the silicon is an integral part of the polymer and does not specifically address photoresists where silicon is incorporated in a post-imaging process step (Such as top-surface-imaging resists). The review is not exhaustive but emphasizes instead specific examples of representative resist chemistry.     

Development and Testing of Energetic Materials: The Concept of High Densities Based on the Trinitroethyl Functionality

The development of new energetic materials is an emerging area of materials chemistry facilitated by a worldwide need to replace materials used at present, due to environmental considerations and safety requirements, while at the same time securing high performance. The development of such materials is complex, owing to the fact that several different and apparently mutually exclusive material properties have to be met in order for a new material to become widely accepted. In turn, understanding the basic principles of structure property relationships is highly desirable, as such an understanding would allow for a more rational design process to yield the desired properties. This article covers the trinitroethyl functionality and its potential for the design of next generation energetic materials, and describes relevant aspects of energetic materials chemistry including theoretical calculations capable of reliably predicting material properties. The synthesis, characterization, energetic properties, and structure property relationships of several new promising compounds displaying excellent material properties are reported with respect to different kinds of applications and compared to standard explosives currently used. Based on a review of trinitroethyl‐containing compounds available in the literature, as well as this new contribution, it is observed that high density can generally be obtained in a more targeted manner in energetic materials taking advantage of noncovalent bonding interactions, a prerequisite for the design of next generation energetic materials.     

Correlation between chemistry of polymer building blocks and microelectronics reliability

Among various materials, polymers are widely used in microelectronics as different product constituents, such as encapsulants, conductive or non-conductive adhesives, underfills, molding compounds, insulators, dielectrics, and coatings. The behavior of these polymer constituents determines the performance, such as functionality and reliability, of the final products. Therefore, the successful development of microelectronics depends on, to some extent, the optimal design and processing of polymer materials. Due to the development trends of microelectronics, characterized mainly by ongoing miniaturization down to the nano scale, technology and functionality integration, eco-designing, shorter-time-to-market, development and application of polymers become one of the bottlenecks for microelectronic industry. Aiming at optimizing the product/process development, we have been spending a lot of effort to understand and design polymer behavior in microelectronics, such as material pre-selection, processing, characterization and modeling. Although these efforts are necessary, the ultimate benefits can only be realized if the relationship between chemistry and the behavior can be understood and predicted. This paper presents some results of our effort to establish the links between chemical details of the polymers and microelectronics reliability.     

Zintl结构化学在热电材料研究中的应用

Zintl相化合物满足“电子晶体-声子玻璃”特征,能够通过化学掺杂和结构修饰来提高其热电性能,是理想的热电材料研究对象。阐明了热电材料性能优化的Zintl结构化学原理,介绍了Zintl结构化学在高性能热电材料研究中的应用,指出利用Zintl结构化学原理寻找高性能热电材料是今后热电材料研究的重要方向。     

Chemically amplified resists: Chemistry and processes

Continued advances in mocroelectronic device fabrication are trying the limits of conventional lithographic techniques. In particular, conventional photoresist materials are not appropriate for use with the new technologies that will be necessary for sub-0.5 μm lithography. One approach to the desing of new resist chemistries involves the concept of chemical amplification, where one photochemical event can lead to a cascade of subsequent reactions that effect a change in solubility of the parent material. The most well-known chemically amplified resists utilise photchemically generated acid to catalyse crosslinking or deprotection reactions. This paper reviews the acid generator, crosslinking, deprotection and depolymerisation chemistries that have been evaluated for chemical amplification resist processes. Additionaly, process characteristics and resist performance relative to the process environment are addressed.     

MEMS机油压力传感器可靠性研究

研究了封装工艺对传感器可靠性的影响。分析和实验结果表明,机油压力传感器封装材料及各个工艺步骤都会影响传感器的性能和可靠性。贴片胶性能不能满足可靠性要求,会引起传感器信号漂移和高温不稳定性;引线键合强度不够,在工作中会断裂;硅油化学稳定和耐温性能不够好,会造成传感器高温输出信号不稳定,硅油中的空气和杂质会造成传感器零点输出偏大,使传感器的精度下降等。     

家装知识库设计与实现

家装行业作为与民生息息相关的重要行业,一直都是群众关心的重点对象。针对目前装饰装修行业存在较多专业化知识,消费者无从辨别建材产品的优劣。对设计、建材、施工等各环节过程是否绿色无从知晓,普通群众对家装行业的知识并没有一个官方认可的渠道进行学习,容易造成认知的偏差。因此,通过信息化手段,实现现有信息资源的整合,对绿色装修的专业知识进行推广普及。搭建一个系统的、标准的、权威专业的知识库系统,为装饰装修行业公共服务平台提供专业知识内容,引导和帮助全行业更好地了解和推进绿色装修。     

On the Welding of Vitrimers: Chemistry,Mechanics and Applications

Linear chains in thermoplastics make them relatively weak in performance but inherently weldable and recyclable. By contrast, thermosets with permanently crosslinked networks possess outstanding mechanical performance, thermal, and chemical stability, but are unweldable and unrecyclable. In the last decade, a kind of thermoplastics-like thermosets termed as vitrimer has been developed with extensive applications, in which welding of vitrimers plays a central and fundamental role. Herein, we present the current state of the art of the welding of vitrimers and discuss the welding of vitrimers from a broad picture of chemistry, physics, and mechanics: i) chemistry and mechanics of the welding of vitrimers; ii) applicability of the mechanical assessment methods for the welding of vitrimers; iii) design principles and implement strategies to the welding of vitrimers; iv) effects of welding conditions on the welding strength and toughness; and v) applications to the adhesion of chemically inert materials. Finally, advantages, challenges, and open questions to the welding of vitrimers are highlighted, and future opportunities in chemistry, mechanics, design of tough welding, artificial intelligence aided programming of welding technology, mechanical assessment standard, and so on are discussed. The development of vitrimer welding would fuse disciplines and make transformative impact in polymer industry.     

High resolution variable-shaped beam direct write

The tendency to smaller feature sizes is continuing in the microelectronic industry. EBDW is a well introduced method for research and development of semiconductor devices. A tool architecture based on the variable-shaped beam (VSB) principle offers a significant throughput advantage compared to any Gaussian beam system. A VSB column with high resolution is presented in this paper which is capable of being applied down to the 32 nm node and below. Starting with electron-optical simulations the major influences on the resolution are considered: i.e. coulomb interaction, geometrical and chromatic aberrations. State of the art dynamic corrections are applied to the main field deflector. However, the manufacturing accuracy has also to be taken into account. A well balanced design was necessary to ensure the manufacturability of the final lens. Knife edge measurements were executed to verify the resolution enhancement. Exposed resist patterns are the most important results with respect to their practical use in the semiconductor industry. Several resists, CAR as well as conventional ones, positive and negative resists were exposed to get a realistic impression regarding the resolution capability of the new column. It was possible to achieve 14 nm single lines in HSQ resist.     

Hot-electron resistance device processing and design: a review

Continual reduction of MOS device size to optimize device performance and reduce die cost has led to reliability concerns. These are attributed to the ever increasing generation of hot electrons that accompany device size reduction. Hence, it is essential to thoroughly understand the relationships governing device performance, design, and reliability with respect to processing. Both the degradation rate and generation of hot electrons can be modified through processing and design. By reviewing various aspects of hot-electron resistance processing and fabrication techniques, guidelines are established which will prove useful in the design of a given process to reduce hot-electron degradation     

Robust Finite Element Model for the Design of Thermoelectric Modules

Thermoelectric devices for power generation have been receiving increased attention as an emerging sustainable energy technology because of recent advances in thermoelectric materials and the tremendous thermal resources available. Little focus has been given to the effective implementation of thermoelectric materials in power generation modules and efficient module design. With recent exploration into new module configurations, it is imperative that a comprehensive model be developed as a design tool. A new three-dimensional, device-level, multiphysics modeling technique is developed for the purposes of designing and evaluating thermoelectric module configurations. Using the new model, we identify and explore several geometric parameters which are critical to module performance. The impact on device performance of solder, ceramic interface, and electrical contact thickness, as well as the leg spacing, is evaluated for a standard unicouple configuration. Results are compared to the standard one-dimensional constant property models commonly used in thermoelectric module design.     

Anomalous acid diffusion in a triphenylene molecular resist with melamine crosslinker

Next generation lithography will require next generation resists. Molecular resists, based on small non-polymeric molecules, promise improvements in line width roughness and resolution control for high resolution lithographic patterns. However, these materials are generally not sensitive enough for commercial application. We have investigated the application of a common chemical amplification scheme to molecular resists. The triphenylene derivative C5/C0 (symmetrical 2,6,11-trihydroxy-3,7,11-tris(pentyloxy)triphenylene), mixed with the crosslinker hexamethoxymethyl melamine and the photoacid generator triphenylsulfonium triflate shows a substantial sensitivity enhancement, requiring a dose of only 5 μC/cm² compared with the pure triphenylene sensitivity of 6500 μC/cm² at 20 keV. Previous work has indicated that the acid diffusion length of the photoacid generator used here is around 350 nm and that the diffusion length decreases with film thickness. However, in this molecular resist system anomalous levels of acid diffusion were observed, indicating that previous results for polymeric systems may not hold true for these new materials. Initial results indicate that the acid diffusion length in this system may be on the order of microns. Furthermore, there is some evidence that the excessive diffusion is occurring in the surface layers of the resist or at the air: resist interface itself.     

Sequence–Structure–Property Relationships of Recombinant Spider Silk Proteins: Integration of Biopolymer Design,Processing, and Modeling

The mechanical properties of spider silks drive interest as sources of new materials. However, there remains a lot to learn regarding the relationships between sequence, structure, and mechanical properties. In order to predict the types of sequence–functional relationships, synthesis–characterization–computation are integrated using recombinant spider silk‐like block copolymers. Two designs are studied, both with origins from the spider Nephila clavipes. These proteins are studied both experimentally and in silico to understand the relationships between sequence chemistry, processing, structure, and materials function. Films formed from the two proteins are thoroughly characterized. In parallel, molecular modeling is used to assess the propensity of the two sequences to form β‐sheets or crystalline structures. The results demonstrate that the modeling predicts the structural differences between the two silk‐like polymers and these features can also be related to differences in functional outcomes. With this example of relating sequence design (hydrophobic–hydrophilic domains), experiment (genetic design and synthesis), processing (film and fiber formation) and modeling (predictions of crystallinity), synergy among these methods is demonstrated for predictable material outcomes. This approach offers a robust discovery path when looking towards next generation approaches to targeted materials outcomes.     

Experimental Characterization of Thermoelectric Modules and Comparison with Theoretical Models for Power Generation

The interest in thermoelectrics for power generation applications has dramatically increased over the past decade as a result of recent advancements in thermoelectric materials. Although measuring thermoelectric properties of materials has received significant attention, measuring thermoelectric module (TEM) power generation performance has received less attention. Characterizing TEMs is vital for validating module-level models used in optimizing TEM designs. Measurements of module performance can also be used for the optimal incorporation of TEMs into power generation systems. A TEM test apparatus has been developed and characterized to test current and future modules under a wide range of temperature and loading conditions. In addition to temperatures and electrical performance metrics, heat rates, and mechanical loading conditions are monitored. The developed technique extracts module parameters, which can be used for system-level design, to measure performance of advanced TEMs, and to validate theoretical models for module design optimization. Experimental results are compared with standard analytical TEM models and a newly developed model.     

含氟紫外纳米压印光刻胶的研制

从主体树脂性质、光引发剂的选择、助剂的选择、溶剂的设计等多个方面论述了含氟纳米压印光刻胶的研制工艺。在纯有机材料为主体的光刻胶中引入了全氟丙烯酸酯助剂,解释了含氟助剂在光刻胶中的作用。使用接触角法评估了全氟丙烯酸酯对光刻胶表面性质的影响,并通过接触角数据预测了光刻胶的脱模能力。通过旋涂、压印、刻蚀等实验验证了光刻胶的性能,并通过实验数据筛选出了最佳配方。研制出的光刻胶样品图形保真度高、分辨率好,对底材有良好的黏附力,且具有良好的脱模能力。     

两面异色阻焊工艺制作技术浅谈概述

随着电子信息产业的快速发展,而印制电路板作为电子产品的核心部件之一,不但在功能方面要求电路密度的极大化及结构精巧化,而且对产品的及外观设计要求也在不断更新与升级。针对印制电路板两面异色的阻焊特殊工艺要求板阻焊制作流程及方式进行探讨。     

微波与化学反应相互作用中的关键问题讨论

微波作为一种高效的加热方法已经在化工各个领域内广泛应用,但是微波和化学反应的相互作用机理还没有真正被认识,这严重制约了高功率微波在化学工业上的进一步应用.从微波与化学反应相互作用的几个关键问题:化学反应的复等效介电系数,微波加热化学反应的数值模拟以及微波非热效应等方面进行了研究和讨论.这些工作将对相关机理研究提供帮助,并有助于从根本上解决目前微波化工应用中亟待解决的难题.     

Materials,process science & technology at Sandia's center for compound semiconductor technology: CCST

The CCST embodies a wide range of capabilities for advancing the stae of the art in compound semiconductor device development. The next generation of devices will depend critically on advances in materials and materials processing, and the CCST has been at the forefront in developing both the new materials and the necessary processing techniques to realize exciting new device concepts. In these efforts, Sandia's CCST is interested in increasingly teaming with the private sector to accelarate the conjunction between research and development and near-term industry applications. Numerous companies are already engaged in collaborative efforts with Sandia; these include     

1D Van der Waals Polymers with Nonlinear Optical Performance Approaching Theoretical Upper Limit

Nonlinear optical (NLO) materials are of great importance for applications in lasers, atomic clocks, free-space communication, etc. Herein, inspired by the recent prediction of excellent second harmonic generation (SHG) performance in van der Waals (vdW) materials with 1D building blocks, 14 new NLO materials are found from 244 bulk crystals constructed with 1D polymers using high-throughput first-principles calculations. Nearly half of the new NLO materials exhibit superior NLO performance with SHG susceptibilities approaching the theoretical upper limit. The 2D form of 11 candidates inherits the NLO property covering UV, visible, and infrared regions. Bader charge analysis reveals that the SHG susceptibility is determined by the charge difference of ions on the chains. Finally, it is proposed that superior NLO materials can be found in materials with proper bandgaps and large charge differences on the chains. This work not only screens out candidates with outstanding NLO performance in vdW materials with 1D building blocks but also provides a guideline for the search and design of NLO vdW 1D polymer patterns with excellent NLO properties.     

激光制备新型石墨烯/铜基复合电触头

为了解决电力系统中关键材料电触头同时受到电弧烧蚀、动静触头相互碰撞产生的冲击载荷和摩擦以及电流产生焦耳热引起的熔焊的问题,提高电气设备的使用性能,发展新型高性能触头材料,提出了一种石墨烯/紫铜复合触头的新型制备方法。采用等离子体辅助加工手段,在质量分数为0.999的紫铜表面上制备出镍铜合金过渡层,在此过渡层上利用高功率连续激光原位制备石墨烯表面薄膜,全覆盖于紫铜基底表面,作为独立涂层来抵抗触头材料所受的破坏,探索了制备石墨烯复合触头材料过程中的等离子体辅助加工工艺以及激光加工工艺。结果表明,石墨烯/铜基触头材料具有优异的电工特性,电阻与紫铜相近,硬度为紫铜的1.8倍,摩擦系数仅为0.06。本研究可为电工材料提供新的解决思路和新的材料体系。