交联型聚甲基丙烯酸酯正性电子束抗蚀剂

<正> 关于交联型聚甲基丙烯酸酯正性电子束抗蚀剂已有报道(1,2)。这种抗蚀剂是由共聚(甲基丙烯酸甲酯—甲基丙烯酰氯)和共聚(甲基丙烯酸甲酯—甲基丙烯酸)两种共     

减小光刻中驻波效应的新方法研究

光刻过程中，抗蚀剂内部光敏混合物（PAC）浓度受光场的影响呈驻波分布，导致抗蚀剂显影后的侧壁轮廓成锯齿状。分析了后烘（PEB）对PAC浓度分布的影响，模拟了不同后烘扩散长度下的抗蚀剂显影轮廓，从模拟结果可知利用后烘可明显减小驻波效应，得到平滑的抗蚀剂显影轮廓，提高光刻质量。     

组成对抗蚀剂干蚀刻敏感度的影响——乙烯基聚合物与光致抗蚀剂

测定了一组乙烯基聚合物抗蚀剂和光致抗蚀剂的等离子体和活性离子蚀刻速率,以及离子铣蚀刻速率;并发现在合成中改变乙烯侧基取代基或改变光致抗蚀剂等20多种因素都会影响蚀刻速率。观察到含有重键及不饱和侧基的乙烯基聚合物抗蚀剂,以及负性印刷体系具有低的蚀刻速率及较好的蚀刻适应性。虽然有二三种乙烯基体系聚合物确实有很好的性能,但光致抗蚀剂体系一般都具有更好的蚀刻适应性。与聚甲基丙烯酸甲酯或SiO_2相比较,除了负性光致抗蚀剂外,乙烯基聚合物的蚀刻选择性和蚀刻方位对三种蚀刻技术都是相当稳定的。     

氯酸钠/盐酸型蚀刻铜再生剂之论述

简介 氯酸钠/盐酸型蚀刻铜再生剂适合于生产多层板的内层和塞孔与湿膜正片流程的印制-蚀刻板,所采用的抗蚀剂是网印抗蚀油墨或干膜抗蚀剂及液态光致抗蚀油墨、金等,不适合于锡-铅合金及纯锡抗蚀剂。其特点是蚀刻速率容易控制、侧蚀小、容铜量大、易再生和回收,减少污染,蚀铜液在稳定状态(包括工艺参     

英国高氏SP2112碱溶性抗酸蚀剂常见故障及对策

故障原囚对策(1)抗蚀剂在氯化铁(FeCI::)过硫酸按[(NH;):S:O、]成氯化铜CoCI:中破坏掉,铜受到侵蚀,可能以针孔或侧蚀形式出现。a.抗蚀剂烘烤不足b.由于预清洁不当,对铜 缺乏附着力。c.抗蚀剂膜太薄d.抗蚀剂过于稀释a.在红外线烘炉内,于120℃ 烘烤3分钟。b.使用化学的或机械的清理 法。C.改用网眼较粗的丝网。d.减少稀释剂的用量。溶剂 过量会使抗蚀剂膜层软化。(2)抗蚀剂难以除去,或颜料残留物留在表面土。b.腐蚀与除抗蚀剂操作间 隔时间太长。C.碱溶液太浓。a.遵照所推荐的烘烤时间和 温度。b.腐蚀后尽快除去抗蚀剂。d.抗蚀剂留在腐蚀…     

PMMA在LIGA技术中的应用

合成了用于LIGA微细加工技术的聚甲基丙烯酸甲酯抗蚀剂,采用同步辐射装置X射线深度曝光,可得到深宽比45－90,深度大于450微米,细线宽5－10微米的良好光刻图形。     

激光一步建立三维微观结构

洛杉矶加州大学(UCLA)的科技人员采用飞秒激光器对商用光敏抗蚀剂SU-8进行单次脉冲发射双光子曝光进行了研究.通过选择的光致抗蚀剂内部的曝光区域,他们能以几兆赫兹的重复频率产生三维结构.     

《微细加工技术》2001年第1～4期主要目次

题目　　　　　　　　　　　　　　　　　　　　　　　　　　　　　作者　　　　期 (页 )电子束技术正交图形簇畸变的校正研究及计算机仿真处理姚作宾　胡咏梅　肖义青　　 2　 (31)………………………电子束曝光高斯分布束斑的ＭｏｎｔｅＣａｒｌｏ模拟任黎明　陈宝钦　　 3　 (6 0 )……………………………………甲基丙烯酸甲酯共聚物作为ＬＩＧＡ抗蚀剂的研究陈永明　彭良强　陈传福等　 3　 (6 4)……………………缩小投影电子束曝光原理论证机彭开武　顾文琪　吴桂君等　 4　 (6 )………………………………………基于ＰＣ机控制的电子…     

正性抗蚀剂系统的边缘锐度和分辨率

本文推导出了抗蚀剂的优值用以估计抗蚀剂组成与工艺条件的各种组合的相应分辨率。抗蚀剂在显影过程中的溶解速率与曝光能量的函数关系的测量。对计算抗蚀剂的优值提供了充足的数据。该方法易于在市售抗蚀剂的组成及其最佳工艺条件之间进行迅速的比较,也运用于电子束和 X—射线复印及负性抗蚀剂,当应用于负性抗蚀剂时,溶解速率的测量方法稍有不同。     

干法腐蚀的抗蚀剂系统研究

本文讨论了干法腐蚀工艺中作掩蔽的抗蚀剂和抗蚀剂系统.分析了在以等离子体为主的干法腐蚀工艺中增强抗蚀剂耐腐蚀能力、降低抗蚀剂腐蚀速率的几种方法.通过实验表明,等离子腐蚀前对抗蚀剂进行等离子体辐照的抗蚀剂处理技术,非常适合于目前国内半导体工艺3～5μm微细加工的需要.     

Impact of the Nature of the Side‐Chains on the Polymer‐Fullerene Packing in the Mixed Regions of Bulk Heterojunction Solar Cells

Polymer‐fullerene packing in mixed regions of a bulk heterojunction solar cell is expected to play a major role in exciton‐dissociation, charge‐separation, and charge‐recombination processes. Here, molecular dynamics simulations are combined with density functional theory calculations to examine the impact of nature and location of polymer side‐chains on the polymer‐fullerene packing in mixed regions. The focus is on poly‐benzo[1,2‐b:4,5‐b′]dithiophene‐thieno[3,4‐c]pyrrole‐4,6‐dione (PBDTTPD) as electron‐donating material and [6,6]‐phenyl‐C₆₁‐butyric acid methyl ester (PC₆₁BM) as electron‐accepting material. Three polymer side‐chain patterns are considered: i) linear side‐chains on both benzodithiophene (BDT) and thienopyrroledione (TPD) moieties; ii) two linear side‐chains on BDT and a branched side‐chain on TPD; and iii) two branched side‐chains on BDT and a linear side‐chain on TPD. Increasing the number of branched side‐chains is found to decrease the polymer packing density and thereby to enhance PBDTTPD–PC₆₁ BM mixing. The nature and location of side‐chains are found to play a determining role in the probability of finding PC₆₁BM molecules close to either BDT or TPD. The electronic couplings relevant for the exciton‐dissociation and charge‐recombination processes are also evaluated. Overall, the findings are consistent with the experimental evolution of the PBDTTPD–PC₆₁BM solar‐cell performance as a function of side‐chain patterns.     

Polymer with conjugated alkylthiophenylthienyl side chains for efficient photovoltaic cells

A donor-acceptor (D-A) conjugated copolymer PSBT-FTT, incorporating alkylthiophenylthienyl (SBT) side chains on benzo[1,2-b:4,5-b']dithiophene units (BDT), was designed and synthesized. Compared to the analogical polymer PSB-FTT with alkylthiophenyl (SB) side chains, PSBT-FTT exhibits stronger interchain π-π interaction, more redshifted absorption spectrum, stronger absorption coefficient, better compatibility with (7,7)-phenyl-C₇₁-butyric acid methyl ester (PC₇₁BM), more effective exciton dissociation and higher hole mobility. Therefore, the PSBT-FTT-based bulk heterojunction polymer solar cells (PSCs) achieved a PCE value of 7.06% that is almost 50% higher than 4.83% of the PSB-FTT based PSCs. The result indicates that the introducing SBT side chains is an excellent strategy for designing high performance photovoltaic polymers.     

Optimization and Analysis of Conjugated Polymer Side Chains for High‐Performance Organic Photovoltaic Cells

Optimization and analysis of conjugated polymer side chains for high‐performance organic photovoltaic cells (OPVs) reveal a critical relationship between the chemical structure of the side chains and photovoltaic properties of polymer‐based bulk heterojunction OPVs. In particular, the impact of the alkyl side chain length on the π‐bridging (thienothiophene, TT) unit is considered by designing and synthesizing a series of benzodithiophene derivatives (BDT(T)) and thieno[3,2‐b]thiophene‐π‐bridged thieno[3,4‐c]pyrrole‐4,6(5H)‐dione (ttTPD) alternating copolymers, PBDT(T)‐(R₂)ttTPD, with alkyl chains of varying length on the TT unit. Using a combination of 2D X‐ray diffraction, Raman spectroscopy, and electrical device characterization, it is elucidated in detail how these subtle changes to the chemical structure affect the molecular conformation, thin film molecular packing, blend film morphology, optoelectronic properties, and hence overall photovoltaic performance. For copolymers employing both the alkoxy or alkylthienyl‐substituted BDT motifs, it is found that octyl side chains on TT unit yield the maximum degree of molecular backbone coplanarity and result in the highest quality of molecular packing and optimized hole mobility. Inverted devices fabricated using this PBDTT‐8ttTPD: polymer/[6,6]‐phenyl‐C₇₁‐butylic acid methyl ester active layer show a maximum power conversion efficiency (PCE) of 8.7% with large area cells (0.64 cm²) maintaining a PCE of 7.5%.     

Electronic structure of fullerene derivatives in organic photovoltaics

The electronic structures of the fullerene derivatives [6,6]-phenyl-C₆₁-butyric acid methyl ester (PCBM), [6,6]-diphenyl C₆₂ bis (butyric acid methyl ester) (bisPCBM), C₇₀, [6,6]-phenyl-C₇₁-butyric acid methyl ester (PC₇₀BM), [6,6]-phenyl-C₆₁-butyric acid butyl ester (PCBB), [6,6]-phenyl-C₆₁-butyric acid octyl ester (PCBO), [6,6]-thienyl-C₆₁-butyric acid methyl ester (TCBM), and indene-C₆₀ bisadduct (ICBA), which are frequently used as n-type materials in organic photovoltaics, were studied by ultraviolet photoelectron spectroscopy and inverse photoemission spectroscopy. We also performed molecular orbital calculation based on density functional theory to understand the experimental results. The electronic structures near the energy gap of the compounds were found to be governed predominately by the fullerene backbone. The side chains also affected the electronic structures of the compounds. The ionization energy and electron affinity were strongly affected by the number of carbons and functional groups in the side chain.     

Enhancing the Charge Transport in Solution‐Processed Perylene Di‐imide Transistors via Thermal Annealing of Metastable Disordered Films

The introduction of side chains in π‐conjugated molecules is a design strategy widely exploited to increase molecular solubility thus improving the processability, while directly influencing the self‐assembly and consequently the electrical properties of thin films. Here, a multiscale structural analysis performed by X‐ray diffraction, X‐ray reflectivity, and atomic force microscopy on thin films of dicyanoperylene molecules decorated with either linear or branched side chains is reported. The substitution with asymmetric branched alkyl chains allows obtaining, upon thermal annealing, field‐effect transistors with enhanced transport properties with respect to linear alkyl chains. Branched chains induce molecular disorder during the film growth from solution, effectively favouring 2D morphology. Post‐deposition thermal annealing leads to a structural transition towards the bulk‐phase for molecules with branched chains, still preserving the 2D morphology and allowing efficient charge transport between crystalline domains. Conversely, molecules with linear chains self‐assemble into 3D islands exhibiting the bulk‐phase structure. Upon thermal annealing, these 3D islands keep their size constant and no major changes are observed in the organic field effect transistor characteristics. These findings demonstrate that the disorder generated by the asymmetric branched chains when the molecule is physisorbed in thin film can be instrumental for enhancing charge transport via thermal annealing.     

Random Copolymers Outperform Gradient and Block Copolymers in Stabilizing Organic Photovoltaics

Recent advances have led to conjugated polymer‐based photovoltaic devices with efficiencies rivaling amorphous silicon. Nevertheless, these devices become less efficient over time due to changes in active layer morphology, thereby hindering their commercialization. Copolymer additives are a promising approach toward stabilizing blend morphologies; however, little is known about the impact of copolymer sequence, composition, and concentration. Herein, the impact of these parameters is determined by synthesizing random, block, and gradient copolymers with a poly(3‐hexylthiophene) (P3HT) backbone and side‐chain fullerenes (phenyl‐C₆₁‐butyric acid methyl ester (PC₆₁BM)). These copolymers are evaluated as compatibilizers in photovoltaic devices with P3HT:PC₆₁BM as the active layer. The random copolymer with 20 mol% fullerene side chains and at 8 wt% concentration in the blend gives the most stable morphologies. Devices containing the random copolymer also exhibit higher and more stable power conversion efficiencies than the control device. Combined, these studies point to the random copolymer as a promising new scaffold for stabilizing bulk heterojunction photovoltaics.     

Side chain effect on photovoltaic properties of D–A copolymers based on benzodithiophene and thiophene-substituted bithiazole

Two donor–acceptor (D−A) copolymers, PEHBDT-BTz and PODBDT-BTz, containing the same backbone of benzodithiophene (BDT) and bithiazole (BTz) units but different side chains were designed and synthesized. Effects of the side chains of BDT and BTz units on solubility, absorption spectra, energy levels, film morphology, and photovoltaic properties of the polymers were investigated. Results showed that the more branched side chains could increase the molecular weight and the introduction of alkylthienyl groups into BTz unit benefits to broaden the absorption and lower the bandgaps as well as deepen HOMO levels, which are propitious to improve the short-circuit current density (J_sc) and open-circuit voltage (V_oc) of photovoltaic cells. Polymer solar cells (PSCs) were prepared with the polymers as electron donors and PCBM as an acceptor. The device fabrication conditions, including the additive, the different acceptor and blend ratio of the polymer donor and acceptor, have been optimized. PCE of PSCs based on the copolymers varied from 2.92% for PODBDT-BTz to 3.71% for PEHBDT-BTz, depending on the type and topology of the side chains on the BDT moiety. The results indicate that an appropriate choice of side chains on the backbone is an effective way to improve photovoltaic performance of the related PSCs.     

1,3,6,8‐Tetraphenylpyrene Derivatives: Towards Fluorescent Liquid‐Crystalline Columns?

Tetraphenylpyrene has been selected as a discotic core to promote liquid‐crystalline fluorescent columns in view of its high fluorescence quantum yield in solution and ease of substitution by flexible lateral side chains. The synthesis and characterization of ten new derivatives of pyrene have been carried out; the pyrene core has been substituted at the 1,3,6,8‐positions by phenylene rings bearing alkoxy, ester, thioether, or tris(alkoxy)benzoate groups on the para position; the compounds have been characterized by mass spectrometry and ¹H NMR and UV‐vis spectroscopies. In order to generate liquid‐crystalline phases, the nature, number, and size of the side chains as well as the degree of polarity around the tetraphenylpyrene core have been varied. However, the desired liquid‐crystalline behavior has not been observed. The supramolecular order together with the absorption and emission properties in solution and the solid state are discussed and compared to theoretical predictions. Quantum‐chemical calculations rationalize the high solid‐state fluorescence of a tetraphenylpyrene derivative for which the crystal structure has been determined.     

Proton‐Conducting Aromatic Polymers Carrying Hypersulfonated Side Chains for Fuel Cell Applications

Polysulfone main chains have been functionalized with hypersulfonated aromatic side chains where the sulfonic acid groups were highly concentrated on a local scale, with two acid groups placed on the same aromatic ring. This molecular design was implemented to promote the nanophase separation that takes place in proton‐exchange membranes between the hydrophobic polymer main chain and the hydrophilic ionic groups responsible for the water uptake and conduction. Morphological investigations revealed that polysulfones functionalized with disulfonaphthoxybenzoyl or trisulfopyrenoxybenzoyl side chains contained larger and more uniform ionic clusters, as compared to conventionally sulfonated polysulfones where the acid groups are dispersed along the main chain. Membranes based on the polymers carrying hypersulfonated side chains formed efficient networks of water‐filled nanopores upon hydration, which facilitated excellent levels of proton conductivity exceeding that of the commercial Nafion membrane at moderate water uptakes.     

Ester-functionalized poly(3-alkylthiophene) copolymers: Synthesis,physicochemical characterization and performance in bulk heterojunction organic solar cells

The introduction of functional moieties in the donor polymer (side chains) offers a potential pathway toward selective modification of the nanomorphology of conjugated polymer:fullerene active layer blends applied in bulk heterojunction organic photovoltaics, pursuing morphology control and solar cell stability. For this purpose, two types of poly(3-alkylthiophene) random copolymers, incorporating different amounts (10/30/50%) of ester-functionalized side chains, were efficiently synthesized using the Rieke method. The solar cell performance of the functionalized copolymers was evaluated and compared to the pristine P3HT:PCBM system. It was observed that the physicochemical and opto-electronic characteristics of the polythiophene donor material can be modified to a certain extent via copolymerization without (too much) jeopardizing the OPV efficiency, as far as the functionalized side chains are introduced in a moderate ratio (<30%) and that preference is given to side chains with a small molar volume. A range of complementary techniques – UV–Vis spectroscopy, (modulated temperature) differential scanning calorimetry, transmission electron microscopy and X-ray diffraction analysis – indicated that variations in polymer crystallinity, while maintaining a high level of regioregularity, are probably the main factor responsible for the observed differences.