超支化聚合物抗蚀剂的感光性能

通过凝胶率对曝光能量的变化,研究显影液、光敏剂用量等对超支化聚合物光致抗蚀剂感光性能的影响.结果表明:四甲基氢氧化胺水溶液对超支化聚合物光致抗蚀剂的溶解能力比碳酸钠强,对感光性具有较大的影响;当显影液相同时,随着引发剂的量增大,E0,gel减小,反差γgel在引发剂的用量为6%时,可达到8.13,E0,gel达到5.5mJ/cm2.     

聚硅烷—高分辨的光致抗蚀剂

概述了光致抗蚀剂在微电子工业中的作用,着重介绍了聚硅烷光致抗蚀剂的特点,以及聚硅烷紫外、深紫外、X射线、电子未等抗蚀剂的发展状况     

高支化碱溶性丙烯酸化聚酯的合成及光固化性能

通过环氧氯丙烷和1,2,4－偏苯三甲酸酐合成高支化碱溶性聚酯,再与甲在丙烯酸缩水甘油酯反应得到高支化碱溶性丙烯酸化聚酯;研究了树脂的组成对感光性和碱溶性的影响;调整反应物料配比,可以获得较好的碱溶性和光固化性能。     

Progress in deep-UV photoresists

Higher resolution can be achieved in lithography by decreasing the wavelength of the exposure source. However, resist material and their processing are also important when we move to a shorter wavelength lithography technology. This paper reviews the recent development and challenges of deep-UV photoresists and their processing technology.     

Advanced lithography simulation for various 3-dimensional nano/microstructuring fabrications in positive- and negative-tone photoresists

Photoresist lithography has been applied to the fabrication of micro/nano devices, such as microfluidic structures, quantum dots, and photonic devices, in MEMS (micro-electro mechanical systems) and NEMS (nano-electro-mechanical systems). In particular, nano devices can be expected to present different physical phenomena due to their three-dimensional (3D) structure. The flexible 3D micro/nano fabrication technique and its process simulation have become among the major topics needed to understand nano-mechanical phenomena. For this purpose, the moving-mask technology and the lithography processes for the positive- and negative-tone photoresists were modeled. The validity of the simulation of the proposed 3D nano/microstructuring was successfully confirmed by comparing the experiment results and the simulated results. Hence, the developed model and the simulation can present and optimize photoresist characteristics and lithography process conditions due to the various 3D nano/microstructures. They could be help in the understanding of nanomaterial and mechanical phenomena.     

光敏纳米SiO2制备及在光致抗蚀材料中的应用

经溶胶-凝胶法制得纳米SiO2,用不同结构的双键硅烷偶联剂对其表面进行原位接枝改性,得到两种光敏纳米SiO2(M70SiO2和M50SiO2),并将其添加到紫外光固化丙烯酸酯预聚物中,制得杂化光致抗蚀材料。通过测定光敏参数(D0n.5)考察其光敏性知,杂化光致抗蚀材料光敏性明显增加,当光敏纳米SiO2的质量分数增至13.7%～15.8%时,光敏参数达25 mJ/cm2～27 mJ/cm2;用差示扫描量热仪(DSC)及热机械分析(TMA)考察抗蚀材料的热性能,结果显示,随光敏纳米SiO2用量增加Tg升高,热膨胀系数减小,同时分辨率和精密性并未因光敏纳米SiO2的加入而降低。     

Method for the Characterization of Extreme-Ultraviolet Photoresist Outgassing

Outgassing from photoresists illuminated by extreme ultraviolet radiation can lead to degradation of the very expensive multilayer-coated optics in an extreme ultraviolet stepper. Reliable quantification of the various organic molecules outgassed by photoresists has been a challenging goal. We have designed a compact system for this measurement. In the first step, the total number of molecules emitted by the photoresist is measured using a pressure-rise method in a closed vacuum chamber, with the pressure measured by mechanical means using a capacitance displacement gauge. To provide identification and relative abundances, the outgassed molecules are then collected in an evacuated trap cooled by liquid nitrogen for subsequent analysis by gas chromatography with mass spectrometry. We will discuss the design and performance of the system.     

Synthesis of novel photoacid generator containing resist polymer for electron beam lithography

Photoacid generators (PAGs) have been widely used as a key material in the development of novel photoresist materials. One of the important uses of PAGs is found in chemically amplified photoresists (CARs) because of their high photosensitivity and high resolution capability. Triphenylsulfonium salt methacrylate (TPSMA) as the PAG has been bounded in the main polymer backbone. TPSMA was employed for synthesis of terpolymers, poly(MMA-co-tBVPC-co-TPSMA) and poly(tBVPC-co-tBOCPOMI-co-TPSMA) as a positive tone photoresists by free radical polymerization using AIBN. Terpolymers with various ratio of TPSMA, MMA, tBVPC and tBOCOPMI were synthesized and well characterized by FTIR, NMR. Molecular weight distribution was analyzed by GPC. Thermal properties were studied using TGA, DSC which showed thermal stability of terpolymer up to 150 degrees C. We have applied E-beam lithography and KrF lithography in order to demonstrate the effect of the polymer bounded PAG resists. These positive tone resists were successfully applied for fabrication of nano-scale patterns.     

A comparative study of different thick photoresists for MEMS applications

This work reports on recent advances in microfabrication process technology for medium to high-aspect ratio structures realised by UV photolithography using different kinds of photoresists. The resulting structures were used as moulds and will be translated into metallic structures by electroplating. We used four types of photoresists: SPR 220-7 novalak based (positive), SU8 epoxy based (negative), Ordyl P-50100 acrylate based (negative) dry film photoresist, and Diaplate 132 acrylate based wet photoresist (negative). The motivation for this work was to find an alternative to SU-8 photoresist, which is difficult to process and remove after electroplating. Depending on the application, we found that Ordyl P-50100 dry film photoresist is the best alternative to SU8 for realization of approximately 100 μ m deep moulds for electroplating in acidic electroplating solution. SPR 220-7 is a good alternative to SU8 for fabrication of 50 μ m deep moulds and electroplating in alkaline solutions. The results presented in this paper will open up new possibilities for low-cost processes using electroplating for MEMS applications.     

Adjustable refractive index modulation for a waveguide with SU-8 photoresist by dual-UV exposure lithography

We present a new fabrication technique based on a two-step UV exposure lithographic process to marginally modulate the refractive index in commercial SU-8 photoresist. This technique achieves refractive index modulation as different regions undergo different thermal densification prior to UV-induced polymerization. A small refractive index contrast of 0.0008 or lower can be achieved, and this is especially useful for fabricating waveguides with a low level of propagation modes. This technique may be extended to other UV-curable epoxy photoresists and can easily be applied in the fabrication of optical elements such as optical interconnects and integrated optical sensors without the development process.     

Photoreactive polymers for electronics

Light-induced changes of the properties of materials are of major imprtance in electronics. This will be illustrated by examples showing the photoresists presently used to produce submicron structures, phot-patternable insulating materials, and UV-curable reactive resins.     

Polymer film selection for corrosion protection of data storage magnetic materials

Due to the current requirement of high recording density of hard disk drive, the thickness of DLC layer which is the protective layer is needed to be reduced. Therefore, the corrosion of read-write elements that are fabricated from soft magnetic materials is more critical. During the photolithography process, polymer photoresist is playing the major role on controlling the corrosion of soft magnetic materials. Two different types of polymer photoresists are selected to investigate, noted as wet photoresist and dry photoresist, respectively. Contact angle measurement, AFM and SEM are techniques using to determine the quality of polymer photoresists. Furthermore, the direct corrosion is also studied by using potentiostat/galvanostat-based measurements. The result suggested that the wet photoresist, AZ4999 Clariant, is better as compared to that of dry photoresist. No surface degradation as well as surface defects of the wet photoresist was found after lithography process. The corrosion rate of the specimen coated by this corresponding wet film is found to be only 1.44 x 10(-6) mm/y. In addition, the wet photoresist surface is hydrophobic posed of more than 75 degree of contact angle.     

PLASMA DEPOSITION OF AMORPHOUS GeSey THIN FILMS AS INORGANIC PHOTORESISTS

Vitreous inorganic photoresists were prepared using plasma enhanced chemical vapor deposition processes in order to match the deposit method to industrial requirements (throughput, area to be covered, deposition rate, integration in a dry process). Their specific morphology (phase separation) resulted in lithographic characteristics (development rate, edges of pattern) related to the composition of the glass. The fineness of the microstructure of germanium-rich glasses (GeSe₃) gives them resolution compatible with submicron lithography.     

几种硫鎓盐类光产酸剂的合成与性质

硫鎓盐类光产酸剂因其较高的产酸效率和好的热稳定性而广泛应用于化学增幅光致抗蚀剂中。本论文选择不同的酚化合物为原料,使之与二甲基亚砜和氯化氢反应,合成了一系列硫鎓盐化合物,研究了其在有机溶剂中的溶解性、热稳定性、紫外吸收性质及其光解特性。以低压汞灯为曝光光源,测定了该类光产酸剂的光解量子效率在0.2—0.7范围。     

微透镜列阵浮雕深度控制的新方法

在对材料光刻阈值特性进行研究的基础上,提出了一种可有效克服材料非线性特性影响,提高微透镜浮雕深度的新方法——基底曝光法。在曝光之前,对抗蚀剂整体施加一定量的曝光,提升抗蚀剂刻蚀基面。该方法可制作出面形均方根误差小于3%的微透镜阵列。     

Interferometric lithography for nanoscale feature patterning: a comparative analysis between laser interference, evanescent wave interference, and surface plasmon interference

In this paper, we experimentally demonstrate and compare single-exposure multiple-beam interference lithography based on conventional laser interference, evanescent wave interference, and surface plasmon interference. The proposed two-beam and four-beam interference approaches are carried out theoretically and verified experimentally, employing the proposed configurations so as to realize the patterning of one- and two-dimensional periodic features on photoresists. A custom-fabricated grating is employed in the configuration in order to achieve two- and four-beam interference.     

高功能材料—聚硅炔的研究现状

本文综述了一类新型的高功能材料——聚硅炔的合成、结构、反应以及作为半导体、导电性SiC薄膜、光学波导器和光致抗蚀剂的应用的研究现状。     

Refractive index modulation in polymer film doped with diazo Meldrum’s acid

Diazo Meldrum’s acid undergoes a photoreaction induced by UV light and it is used as photosensitizer in photoresists. Upon photoreaction, a change in refractive index occurs, which makes this system interesting for volume holography. We report on the sublimation effect at room temperature and the effect of photoirradiation on the refractive index in thin films of CAB (Cellulose acetate butyrate) doped with different amount of diazo Meldrum’s acid. A net modulation of the refractive index of 0.01 is achieved with 40% of doping ratio together with a reduction of the film thickness.     

Surface desorption of gases from photoresist

This work describes the analysis of gases desorbed in vacuum from photoresists manufactured by Shipley and Kodak, as a function of temperature. Test samples were prepared by spin coating of a special heating element prepared by photolithographic techniques on a nichrome, gold-coated alumina substrate, the degassing of this type of heating element is relatively low by comparison to that of the photoresist. The analysis of gases desorbed was performed at a pressure of 10^?6 torr utilizing a monopole mass spectrometer. The type of photoresist and temperature were the determining factors in the quantity and species of gases desorbed. In this manner the breakdown temperature of each type of photoresist was determined. The results of this work aid in choosing a photoresist compatible with microelectronic vacuum technology.     

Fabrication of High-Resolution Gamma-Ray Metallic Magnetic Calorimeters with Ag:Er Sensor and Thick Electroplated Absorbers

We are developing metallic magnetic calorimeters for high-resolution gamma-ray spectroscopy for non-destructive assay of nuclear materials. Absorbers for these higher-energy photons can require substantial thickness to achieve adequate stopping power. We developed a new absorber fabrication process using dry-film photoresists to electroform cantilevered, thick absorbers. Gamma detectors with these absorbers have an energy resolution of 38 eV FWHM at 60 keV. In this report, we summarize modifications to STARCryo’s “Delta 1000” process for our devices and describe the new absorber fabrication process.