厚胶光刻中曝光光强对光化学反应速率的影响

针对用于厚层光刻的重氮萘醌类正性光刻胶,利用动力学模型,分析了光化学反应速率的影响因素;给出了光化学反应速率明显受光强变化的影响以致互易律失效的原因。对厚度24μm的光刻胶AZP4620在相同曝光量而光强分别为3.2mW/cm2和0.63mW/cm2的条件下进行了数值模拟和实验。当曝光光强为3.2mW/cm2时仅需300s,即可显影完全,而当曝光光强为0.63mW/cm2时需要的时间长达2400s,才显影完全,且面形轮廓差异较大。因此,在厚胶光刻中,当曝光光强较大时应适当减小曝光量,反之,应适当增加曝光量。     

紫外曝光在ZrO2薄膜上引入微结构的研究

以锆酸丁酯和苯甲酰丙酮为源,结合Sol-gel工艺,以溶液浸渍法制备具有负性光刻胶性质的ZrO2光敏凝胶.再通过掩膜紫外曝光经显影工艺获得光栅周期在2～10μm,深度120～200nm的ZrO2薄膜光栅.采用紫外分光光度计、红外分光光度计、AFM监控图形转移过程研究了图形精确转移的工艺并优化了工艺参数.     

光刻胶光学性质的光谱椭偏测量方法研究

利用相调制型光谱椭偏仪研究了光刻胶光学常数的测量方法,针对测量过程中光刻胶曝光控制优化了测量方案和仪器参数。对常见的S9912正型光刻胶,给出了曝光前后275～650 nm波段的光学常数。并采用动态椭偏法测量了所需波长下曝光前的光学常数。实验结果表明:该测量方法适用于光刻胶在紫外-可见-红外宽波段的光学性质研究,在光刻模拟、新型光刻胶材料研制及其光学性质表征等领域有重要实用价值。     

江师正型光刻胶全息特性的实验研究

光刻胶(光致抗蚀剂)是一种有机光敏材料,有正胶和负胶两种类型。负胶中,曝光时吸收了光的部分变成不溶性的,在显影阶段只有未曝光的部分被显影液除去,因而用负胶记录的浮雕像对基片的附着力强烈依赖曝光量。正胶则相反,胶层对基片已有足够的附着力,吸收的光子使分子发生光分解反应,因此材料软化,在显影阶段将曝光了的分子除去。故正胶是记录表面浮雕全息图的理想材料。国外广泛采用的是Shipley公司AZ-1350序列正胶,对这种光刻胶的性能已有全面研究。     

非晶态和纳米晶碳化硅薄膜的制备及力学性能

以SiC超细粉为原料、利用热等离子体PVD(TPPVD)技术快速制备出了优质非晶态和纳米晶SiC薄膜.用扫描电子显微镜、高分辨透射电子显微镜、X射线衍射和X射线光电子谱、红外分光谱对薄膜的微结构进行了观察和分析.用纳牛力学探针测量了薄膜的力学性能.研究结果表明,只有当基板温度低于600℃、粉末供给速度不超过20mg/min时可沉积非晶态SiC薄膜,最大沉积速度达到25nm/s;当基板温度在600℃～1000℃时沉积的β-SiC薄膜是晶粒大小为3 nm～5 nm的纳米晶薄膜,最大沉积速度达到230 nm/s.非晶态和纳米晶SiC薄膜的硬度分别达到33.8 GPa和38.6 GPa.     

负性SiO2/ZrO2光敏凝胶薄膜上引入微结构的研究

以锆酸丁酯及乙酰丙酮、苯甲酰丙酮为原料，经溶胶-凝胶工艺，制备具有负性光刻胶性质的ZrO2光敏溶胶，在将其与正硅酸乙酯通过水解缩聚反应复合，采用浸渍提拉法在基片上制得折射率在1．463-1．647之间连续可调的SiO2／ZrO2二元光敏凝胶薄膜．其敏感波长在335nm附近．通过FTIR分析，发现凝胶薄膜中含有Si-O-Zr、Zr-O的特征振动峰，证明SiO2与ZrO2两相在分子尺度上形成了微观组分均匀的薄膜．利用掩模板结合紫外曝光及显影工艺在凝胶膜上转移了光栅等表面微结构图形．     

用于EUV图案化的新型氧化锌簇交联策略的辐射化学（英文）

由于C=C双键交联反应机制的成熟,金属氧化物光刻胶得到了广泛的发展.然而,由于不稳定的C=C双键,这种材料需要低温和遮光存储.在此,首次在金属氧簇中提出了C-F键交联策略用于光刻图案化.以光刻胶Zn-TBA为例,它形成光滑无缺陷的薄膜,且表面粗糙度R_q小于0.2 nm.使用极紫外(EUV)干涉掩模,在65 mJ cm^-2曝光剂量下形成37.5 nm的半周期(HP)图案.在EUV曝光和正己烷显影后,通过原子力显微镜(AFM)观察到负性光刻胶形貌.重要的是,Zn-TBA可以在室温和明亮的环境中储存.除了脱羧之外,我们还提出光引发的C-F交联是Zn-TBA图案的主要贡献者,并通过高分辨率X射线光电子能谱(HRXPS)和密度泛函理论(DFT)计算得以证明.这种新颖的光刻机制为下一代金属基材料的设计提供了新的思路.     

Fe/Si多层膜经快速热退火合成β-FeSi_2薄膜的研究

采用磁控溅射仪在高阻Si(100)衬底上沉积了[Fe(0.5nm)/Si(1.6nm)]120和[Fe(1nm)/Si(3.2nm)]60多层膜,并在Ar气气氛下进行了1000℃,10s的快速热退火。为了比较,也进行了880℃,30min的常规退火。采用X射线衍射仪、原子力显微镜、光谱仪和霍尔效应仪分析了样品的晶体结构、表面形貌、光吸收特性和电学性能。结果表明:Fe/Si多层膜法合成的样品均为β-FeSi2相且在(220)/(202)方向择优生长;经快速热退火合成的β-FeSi2薄膜光学带隙约为0.9 eV。[Fe(1nm)/Si(3.2nm)]60多层膜经快速热退火合成的β-FeSi2薄膜表面粗糙度最小,该薄膜样品为p型导电,载流子浓度为4.1×1017cm-3,迁移率为48cm2/V.s。     

紫外光刻加工误差实验

为研究基于紫外光刻加工技术的光刻胶模型形状误差与工艺参数的关系,利用正交实验法对正性光刻胶AZ9260进行了实验研究引入田口方法关于信噪比统一测度的思想,获得了各加工工艺参数对光刻胶模型加工误差的影响显著度,其中甩胶速度、曝光时间和显影时间为显著因素．对所获得的光刻胶模型电镜图片采用了一种改进的Canny算法,实现了图像边缘提取进而对加工误差的表征与量化方法进行了研究,获得了10～30gm尺度的方形、直线和圆形图形的尺寸误差、直边直线度和直角圆化误差值．研究表明,图形的尺寸误差和直边直线度误差与图形尺寸之比随图形尺寸变大而变小,直角圆化的圆角半径不大于2μm．     

国内外光刻胶发展及应用探讨

正光刻胶是由感光树脂、增感剂和溶剂为主要成分的一种对光特别敏感的混合液体,别名为"光致抗蚀剂"。光刻胶对光非常敏感,透过光线,其化学特性就会发生变化,因此把光刻胶涂敷在硅基片上,再经过曝光、显影、刻蚀等工艺,就可以将设计好的图形复刻到硅基片上,因此光刻胶成为了光电信息产业中图形复刻加工技术中的关键性材料,在其行业内得到了广泛的应用。     

Nickel pulse reversal plating for image reversal of ultrathin electron beam resist

The effects of various pulse reversal plating parameters on the grain size and smoothness of Ni film on silver seed layers has been studied. The duty cycle, frequency, bath temperature and agitation methods have been tested. The objective was to form a thin continuous hard etch mask (20-30 nm of thickness) of Ni films for image reversal of thin film resist using electroplating. While nickel sulfamate solution without additives or brighteners has been used to plate Ni films, reactive ion etching (RIE) has been used to test the durability of the plated Ni films in fluorine plasma. It was found that pulse reversal plating with current intensity of 12 mA/cm², duty cycle of 90%, bath temperature of 45 °C, ultrasonic agitation of power 80 W, and 400 kHz wave frequency resulted in a plating rate as low as 0.2 nm/s. This plating rate made the control of the film thickness an easy task to achieve. This yielded to a smooth plated surface free from defects or voids, with 25 nm film thickness. Combining electron beam lithography with pulse reversal plating for image reversal and RIE offers the prospect of patterning patterns with the desired aspect ratio. Holes of 100 nm diameter, 250 nm period, and 300 nm depth are achieved using this process.     

A high resolution water soluble fullerene molecular resist for electron beam lithography

Traditionally, many lithography resists have used hazardous, environmentally damaging or flammable chemicals as casting solvent and developer. There is now a strong drive towards processes that are safer and more environmentally friendly. We report nanometre-scale patterning of a fullerene molecular resist film with electron beam lithography, using water as casting solvent and developer. Negative tone behaviour is demonstrated after exposure and development. The sensitivity of this resist to 20?keV electrons is 1.5 × 10(-2)?C?cm(-2). Arrays of lines with a width of 30-35?nm and pitches of 200 and 400?nm, and arrays of dots with a diameter of 40?nm and a pitch of 200?nm have been patterned at 30?keV. The etch durability of this resist was found to be ～2 times that of a standard novolac based resist. Initial results of the chemical amplification of this material for enhanced sensitivity are also presented.     

Formation of dot arrays with a pitch of 20 nm × 20 nm for patterned media using 30 keV EB drawing on thin calixarene resist

We studied the possibility of achieving very fine-pitch dot arrays with a pitch of 20?nm × 20?nm using 30?keV electron beam (EB) drawing on negative calixarene resist. In order to form such patterns, we studied the dependence on resist thickness of the dot size and the packing. We propose EB drawing on an extremely thin film for very highly packed dot-array formation. Our experimental results demonstrate the possibility of forming highly packed dot-array patterns with a pitch of 20?nm × 20?nm and a resist thickness of about 13?nm, which corresponds to about 1.6?Tbits?in(-2).     

Production of ultrafine atmospheric pressure plasma jet with nano-capillary

The atmospheric pressure plasma jet (APPJ) has been developed to apply to the ultrafine process for future material processing. In this study, we tried to reduce the diameter of APPJs by using micro- or nano-capillary tubes. To measure the existence of the bullet-like charged particles from the capillary tip, the plasma flow generated from capillary tubes with a diameter of about 100 nm to 5 μm were analyzed by the electrostatic probe. The average propagation velocities of the plasmas flow were estimated from the time differences between the probe signal and spiky discharge current signal. The results show that the velocity of plasma jet delivered from 1 μm ? capillary gradually decreased from 11 to 2 km/s due to a collisional drag force with air with an increase of the distance from capillary tips. From the analysis of etching pattern of resist film by the APPJ with a 500 nm diameter capillary, it was confirmed that the depth and width of the treated trench on the resist film were roughly 30 - 50 nm and 500 - 700 nm, respectively.     

Absolute measurements of radiation damage in nanometer-thick films

The problem of absolute measurements of radiation damage in films of nanometer thicknesses is addressed. Thin films of DNA (～2-160 nm) are deposited onto glass substrates and irradiated with varying doses of 1.5-keV X-rays under dry N(2) at atmospheric pressure and room temperature. For each different thickness, the damage is assessed by measuring the loss of the supercoiled configuration as a function of incident photon fluence. From the exposure curves, the G-values are deduced, assuming that X-ray photons interacting with DNA deposit all of their energy in the film. The results show that the G-value (i.e. damage per unit of deposited energy) increases with film thickness and reaches a plateau at 30±5 nm. This thickness dependence provides a correction factor to estimate the actual G-value for films with thicknesses <30 nm thickness. Thus, the absolute values of the damage can be compared with that of films of any thickness under different experimental conditions.     

膜层厚度对Ag/TiO膜透光隔热性能的影响

采用磁控溅射工艺制备了玻璃基Ag/TiO_2膜,并研究了膜层厚度对其透光隔热性能的影响。结果表明:当Ag膜厚度由6.7 nm增加到9.5 nm时,红外光的平均透过率由42.06%减小到7.70%,隔热温差由1.9℃增大到5.7℃,而可见光的平均透过率则呈现出先增加后减少的变化趋势,当Ag膜厚度为7.7 nm时,复合膜的可见光平均透过率达最大值,为70.85%;当Ti O_2膜厚度由4.1 nm增加到16.7 nm时,红外光的平均透过率由34.12%增大到38.28%,而可见光的平均透过率与隔热温差均呈现出先增大后减少的变化趋势,当Ti O_2膜厚度为10.4 nm时,复合膜的可见光平均透过率达最大值,为70.85%,而厚度为13.6 nm时,膜的隔热温差达最大值,为5.2℃。     

不同制动速度下C/C复合材料摩擦面研究

采用MM-1000型摩擦磨损试验机测试了粗糙层基体炭C/C复合材料试样在不同制动速度下的摩擦磨损性能, 借助微区拉曼光谱和扫描电镜研究了试样摩擦面的结构与形貌。结果表明粗糙层基体炭C/C复合材料具有优异的摩擦速度特性。试样的摩擦系数和试验后摩擦面上碳原子的有序度无直接对应关系, 制动速度对摩擦系数的影响应归因于制动速度对摩擦面温升和摩擦膜厚度及完整性的影响。5m/s的低制动速度下, 试样因吸附水气摩擦系数持续低值(0.15), 摩擦面上无连续摩擦膜产生; 10m/s的制动速度下水气被解吸附, 摩擦面出现多层厚膜, 摩擦系数达到峰值(0.5), 此后, 随制动速度增加, 摩擦膜减薄, 材料磨损量呈下降趋势; 当制动速度增加到25m/s及以上, 摩擦面的温升导致氧化质量损失和线磨损增加, 摩擦系数也稍有衰减(0.3)。      

Film thickness dependence of microstructures and magnetic properties in single-layered FePt films by in-situ annealing

The FePt films with various thicknesses (t) of 5 to 50 nm are deposited on Si(100) substrate without any underlayer by in-situ annealing at substrate temperature (Ts) of 620 °C. A strong (001) texture of L1₀ FePt film is obtained and presents high perpendicular magnetic anisotropy as the film thickness increases to 30 nm. By further increasing the thickness to exceed 30 nm, the (111) orientation of L1₀ FePt is enhanced greatly, indicating that the quality of perpendicular magnetic anisotropy degrades when the thickness of the FePt film is greater than 30 nm. The single-layered FePt film with thickness of 30 nm by in-situ depositing at 620 °C shows good perpendicular magnetic properties (perpendicular coercivity of 1033 kA/m (13 kOe), saturation magnetization of 1.08 webers/m² and perpendicular squareness of 0.91, respectively), which reveal its significant potential for perpendicular magnetic recording media.     

Electrical Force Microscopy measurements on nanoconductors deposited by electropulsed SPM

The reduced dimensions of novel integrated devices and systems stresses the need for new nanopatterning techniques. We showed that metallic pixels of about 30 nm can be deposited by electropulsed SPM. Deposition is obtained by applying −12 to −17 V pulses to a tip coated with a CoCr metallic film while scanning in tapping mode AFM. By assembling arrays of these pixels it is possible to obtain custom-shaped conductors. We deposited rectangular conductors with dimensions from 50×100 nm up to 2000×400 nm and thickness between 2 and 3 nm.A typical conductor line of 2000×400 nm deposited at 40 Hz pulse frequency, 800 nm/s tip velocity and at a line density of 0.64 nm⁻¹ shows a thickness of approximately 3 nm. For electrical measurements this line is deposited perpendicularly and welded from the edge of a conventional Al pad used for microelectronics. The opposite end of the nanoconductor line is located by AFM and the electrical conductivity is then asserted using the conductive AFM tip in Electrical Force Microscopy (EFM) mode.     

Most unstable waves of a stagnant planar liquid film blown by a high speed viscous gas with a Blasius velocity profile

Summary The linear most unstable waves generated on the surface of a stagnant planar liquid (gasoline) film with infinite thickness, blown by a high speed viscous gas (air) with a Blasius velocity profile, are computed and analyzed. The free-stream velocity of the gas ranges from 30 m/s to 50 m/s, which is typical of high speed atomization problems. The Reynolds number based on the local thickness of the boundarylayer lies between 200 and 2500. The numerical computation shows that the dimensional wavelength of the most unstable wave is a power functions of the boundary-layer thickness (or Reynolds number) with a power close to 3/4, while the growth rate is inversely proportional to the boundary-layer thickness. When reducing the boundary-layer thickness, the visocus results approach the inviscid results. This result shows that, under the present parameter range, the gas viscosity would have a secondary role on the atomization speed and important influence on the droplet size.