光刻胶灰化用于全息离子束刻蚀光栅制作

针对全息离子束刻蚀衍射光栅制作中，光刻胶光栅浮雕图形的制作是至关重要和困难的，引入伤反应离子刻蚀对光刻胶光栅进行灰化处理，给出光刻胶灰化技术在全息离子束刻蚀衍射光栅制作闪耀光栅、浅槽矩形位相光栅、自支撑透射光栅中的具体应用。实验结果表明，这一新工艺的突出优点是降低了苛刻的全息曝光、显影要求，使得光栅线条光滑、线空比和槽深可控。     

ICP刻蚀GaP表面形貌控制

不同角度的GaP表面形貌刻蚀主要依赖于刻蚀参数的调节以及光刻胶的形貌,但要得到能够重复的光刻胶形貌是很困难的.研究了如何通过调节感应耦合等离子（ICP）刻蚀仪器本身的参数,而不依赖于不定的光刻胶形貌来得到可重复的表面形貌.通过研究可知,射频功率与腔室压强是影响表面形貌的最重要的两个参数.射频功率越小刻蚀得到的角度越大,腔室压强越大刻蚀得到的角度也越大.通常BCl3等离子体被用来作为GaP的刻蚀气体,但为了维持所需的等离子浓度以及更大的操作压强,Ar被加入刻蚀气体中.     

低压压印制备硅点阵结构的工艺研究

高密度、图形规则的硅点阵结构由于其独特的光电性能具有广泛的应用前景.本文介绍了一种以低压压印结合反应离子刻蚀制备硅点阵的方法,即利用PDMS模板通过压印复制获得PMMA掩模结构,用反应离子刻蚀在硅片表面制得高度有序的硅纳米点阵结构.实验和有限元模拟结果表明,低压压印因为毛细作用下光刻胶在模板内的充分填充可以获得良好的图形复制精度和较小的残余胶厚度,因此适于大面积高密度光刻胶结构的均匀复制.     

光刻胶灰化用于全息离子束刻蚀光栅制作

针对全息离子束刻蚀衍射光栅制作中,光刻胶光栅浮雕图形的制作是至关重要和困难的,引入O2反应离子刻蚀对光刻胶光栅进行灰化处理,给出光刻胶灰化技术在全息离子束刻蚀衍射光栅制作闪耀光栅、浅槽矩形位相光栅、自支撑透射光栅中的具体应用。实验结果表明,这一新工艺的突出优点是降低了苛刻的全息曝光、显影要求,使得光栅线条光滑、线空比和槽深可控。     

二维亚波长结构石英紫外压印模板的制备

利用紫外光刻和反应离子刻蚀技术在石英衬底上制备二维亚波长结构的压印模板,并对模板进行表面修饰.研究了主要刻蚀工艺参数对刻蚀速率及刻蚀形貌的影响.增加工作气压,刻蚀速率先增大到最大值,然后下降;增加射频功率可以提高刻蚀速率,但功率过大会导致刻蚀产物发生二次沉积;延长刻蚀时间可以增加刻蚀深度,但时间过长会发生过刻蚀现象.在优化的刻蚀工艺条件下制备出了较为理想的亚波长石英模板.经表面修饰后,模板表面与水的接触角增大,有效克服了压印胶的粘连,并在ZnS衬底上压印出了良好的二维亚波长结构图形.     

锗表面二维亚波长结构的反应离子刻蚀制备

为了获得具有金字塔结构的二维亚波长结构表面,提高其高宽比,用掩模曝光光刻及反应离子刻蚀技术,以SF6和O2为反应气体,在Ge衬底上制备了二维亚波长结构.用扫描电镜对刻蚀图形的形貌进行了观察,研究了功率、气压、气体流量及掩模图形对刻蚀图形的影响.结果表明:刻蚀图形腰部被优先刻蚀,形成凹陷的侧壁轮廓;O2流量增大有利于在侧壁形成保护层,从而减小腰部刻蚀、增大顶部及根部刻蚀;功率及气压过大或过小均会使侧壁刻蚀较大;方形图案比圆形图案掩模更有利于刻蚀出深度较大的亚波长结构.     

C_(4)F_(6)/SF_(6)混合气体对硅基材料的ICP刻蚀工艺研究北大核心CSCD

为避免深硅刻蚀工艺所引起的扇贝纹效应,同时减少其工艺气体所带来的温室效应,本文将新一代环保电子刻蚀气C4F6引入硅刻蚀工艺,采用刻蚀与钝化同步进行的伪Bosch工艺刻蚀硅槽孔。研究了ICP功率、RIE功率、腔体压强和C_(4)F_(6)/SF_(6)气体流量比对刻蚀速率、光刻胶/硅刻蚀选择比及刻蚀形貌的影响。结果表明,一定程度增加ICP功率和RIE功率可分别提高等离子体密度和物理轰击刻蚀作用;腔体压强对粒子平均自由径有较大影响;而C4F6流量的增加可加强刻蚀侧壁保护机制。通过综合优化工艺参数,获得了2.8μm/min硅刻蚀速率,3.1的光刻胶/硅刻蚀选择比和侧壁平坦,表面光滑,垂直度高的刻蚀形貌。     

薄膜体声波滤波器AlN压电薄膜的ICP刻蚀研究北大核心CSCD

随着5G通信技术的发展,通信频段不断提高,以氮化铝(AlN)为压电薄膜材料的薄膜体声波滤波器作为目前唯一可集成的射频前段滤波器成为研究热点之一。本文开展AlN材料刻蚀工艺的实验研究,实验中采用光刻胶作为刻蚀掩膜,Cl2/BCl3作为刻蚀工艺气体,通过一系列工艺影响参数调整及相应刻蚀结果分析,获得了ICP源功率、RF偏压功率、腔体压强和BCl3气体流量对AlN材料和光刻胶掩膜刻蚀速率、刻蚀形貌的影响规律。通过综合优化工艺参数,最终得到了侧壁平坦、表面光滑的空气隙型薄膜体声波滤波器三明治结构。     

石英和BK7玻璃的离子束刻蚀特性研究

石英和BK7玻璃是常用的光学材料和微系统材料.用Ar作为工作气体对石英和BK7玻璃及其掩模材料AZ1350的离子束刻蚀特性进行了研究,分析了离子能量、离子束流密度和离子束入射角等几种因素对刻蚀速率和选择比的影响,结合相关理论得到了相应的刻蚀速率拟合方程.AFM测量结果表明刻蚀工艺对材料的低损伤.由于与光刻胶的刻蚀选择比较低,随着石英和BK7玻璃刻蚀深度的增加,图形转移精度下降.因此提高刻蚀选择比是获得高分辨率图形的前提.     

HfO2薄膜的反应离子刻蚀特性研究

研究了HfO2薄膜在CHF3/Ar和SF6/Ar等气体中的反应离子刻蚀机理.结果表明刻蚀气体的组分和射频偏压对刻蚀速率有较大影响,而气体流量影响不大.CHF3和SF6与HfO2的反应产物具有较好的挥发性,Ar的引入不仅可以打破分子之间的键合促进刻蚀产物的形成,而且通过轰击加快产物从材料表面解吸,从而提高HfO2刻蚀速率.AFM测量结果表明刻蚀降低了HfO2表面粗糙度,显示刻蚀工艺对材料的低损伤.     

A novel deep etching technology for Si and quartz materials

A disadvantage of ICP type plasma etching method compared with CCP one is low selectivity to photo resist. So a novel etching method was developed to obtain high selectivity to photo resist by incorporating a sputtering method, in which a target was placed on the opposite side of the substrate. Satisfactory results were obtained for a continuous gas feeding treatment and also for a gas modulating treatment.     

MEMS中硅湿法深槽刻蚀工艺的研究

针对硅基MEMS湿法深槽刻蚀技术的难点,在硅材料各向异性腐蚀特性的基础上探索了湿法工艺。对腐蚀液含量、温度、添加剂含量对刻蚀速率及表面粗糙度的影响,掩膜技术等进行了实验研究,优化得到了最佳刻蚀条件。应用该技术成功地刻蚀出深度高达330μm的深槽,为MEMS元器件的加工提供了一种参考方法。     

Microcontact printing of indium metal using salt solution “ink”

Poly(dimethlysiloxane) stamps were made from Si masters fabricated using photolithography and anisotropic etching. GaCl₃ and In(NO₃)₃ were microcontact printed onto Si substrates, creating arrays of micron size metal salt deposits. The In(NO₃)₃ deposits were further processed by annealing in an N₂ :H₂ (9:1) forming gas environment at 600 °C which converted the deposits into In metal. The ability to inexpensively pattern metal arrays on semiconductor surfaces has implications for ohmic contacts and, with additional processing, arrays of semiconductor crystallites for optoelectronic applications.     

Effect of gas introduction position on substrate etching by means of Ar-dominated graphite-cathodic-arc plasma beam in μT-FAD

Substrate etching by means of Ar-mixed graphite-cathodic-arc plasma beam was investigated in a newly-developed compact-type μT-FAD. The surface level and roughness change were measured as a function of the Ar gas flow rate, when Ar gas was introduced into the arc generation zone and in the vicinity of the substrate. When Ar gas was introduced to the arc generation zone, the etching rate was lower but the surface was relatively not roughened. When Ar gas was introduced in the vicinity of the substrate, the etching rate was higher but the surface was roughened. At the same gas flow rate (and pressure), the substrate was etched more than three times faster when Ar gas was introduced into the arc generation zone than to the vicinity of the substrate. After measuring the discharge and plasma conditions, the results were considered to be caused by the difference in the amount of plasma transported to the substrate.     

粗化液中钯离子对ABS塑料直接电镀的影响

粗化是实现活化液在ABS表面吸附的前提和获得良好结合力的必要条件.采用含痕量钯离子的铬酐-硫酸粗化液对ABS塑料表面进行化学粗化,用AFM、XPS和胶体钯吸附量等对粗化前后塑料的表面性能、价键状态和活性进行了考察.结果表明:钯离子加入到粗化液中对ABS表面的粗糙度影响不显著,粗化后的表面氧含量升高;随着粗化液中钯离子浓度的增加,胶体钯在ABS表面上的吸附量增加;增加粗化液中的Pd含量可使ABS表面在低浓度胶体钯溶液中达到与高浓度钯相同的吸附量,有效地降低了胶体钯的浓度.粗化液中加入钯离子不影响基体与镀层的结合力.     

Effect of process parameters and optimization for photochemical machining of brass and german silver

This article focuses on parametric optimization for photochemical machining (PCM) of brass and german silver. The aim of the study is to analyze the effect of control parameters on response measures, that is, surface roughness, material removal rate, and edge deviation and optimization of parameters considering different weight percentage for each performance measure. The control parameters have been selected as etchant concentration, etching temperature, and etching time. Using full factorial method of design of experiments, PCM has been carried out using ferric chloride as etchant. Surface roughness and edge deviation should be less, while material removal rate is desired high. For satisfying this multi-objective condition, overall evaluation criteria (OEC) have been formulated by assigning different and equal weight percentage to response measures. The optimized condition for particular OEC is obtained, and analysis of variance (ANOVA) has been performed for observing effect of control parameters on response measures. Surface topography study has been performed using scanning electron microscopy, and material composition analysis has been carried out using energy dispersive spectroscopy. The surface roughness is observed lower for brass, while the edge deviation is found lesser for german silver. The material removal rate is observed higher for brass compared to german silver.     

2A12铝合金基体超疏水表面制备及性能研究

铝合金在使用过程中极易引发基体腐蚀现象,如点蚀、晶间腐蚀等,为保障铝合金在腐蚀环境中的应用,可通过建立超疏水表面改变铝合金表面的润湿性,从而在一定程度上减少腐蚀液与铝合金表面的接触,进而改善耐蚀性。本文通过酸刻蚀和沸水刻蚀两种方法在铝合金表面构筑微纳米结构,并使用低表面能物质硬脂酸进行表面处理得到超疏水表面。采用扫描电子显微镜、接触角测试仪、原子力显微镜分别对铝合金表面形貌、疏水性和粗糙度进行测试,得到两种方法的最佳制备时间,而后通过极化曲线对两种方法制备的铝合金表面耐蚀性能进行对比,进而研究两种刻蚀方法对铝合金耐蚀性的影响。实验结果表明：酸刻蚀时间为15 s时,铝合金表面接触角达到峰值163.9°,呈现超疏水状态,相对于空白样品,表面粗糙度增加了24倍,电化学自腐蚀电位正向移动0.362 8 V;沸水刻蚀时间为1 min时,其表面接触角达到峰值109.6°,比空白样品疏水性强但未呈现超疏水状态,相对于空白样品,经沸水刻蚀的铝合金表面粗糙度增加了4.4倍,电化学自腐蚀电位正向移动0.074 8 V。两种方法处理得到的铝合金表面的耐蚀性与空白铝合金试样相比均有显著提高,而酸刻蚀法的缓蚀效...     

Process optimization of CF4/Ar plasma etching of Au using I-optimal design

In this paper, reactive ion etching of Au is performed with CF₄/Ar gases, and process optimization method is suggested using a statistically established process model. The I-optimal design was employed to set up the etching experiment with operating parameters, namely, gas composition, RF power and chamber pressure. Its analysis was performed on individual parameters of the etch rate, selectivity, and profile. In addition, process optimization, including all three responses of interest, is provided simultaneously. We confirmed that a nonvolatile by-product AuF_x was re-deposited on the surface, but controlling the amount of carbon fluoride provided a good etch rate with a satisfactory sidewall profile by reducing by-products. Although RF power is closely related with etch rate, increased power gives poor selectivity due to increased physical etching. Pressure and gas flows strongly interact with each other, affecting sidewall characteristics. Suggested optimization simultaneously considers three responses of interests, which is crucial in process development and optimization for quickly ramping up high volume manufacturing.     

Durable diamond-like carbon templates for UV nanoimprint lithography

The interaction between resist and template during the separation process after nanoimprint lithography (NIL) can cause the formation of defects and damage to the templates and resist patterns. To alleviate these problems, fluorinated self-assembled monolayers (F-SAMs, i.e.?tridecafluoro-1,1,2,2,tetrahydrooctyl trichlorosilane or FDTS) have been employed as template release coatings. However, we find that the FDTS coating undergoes irreversible degradation after only 10 cycles of UV nanoimprint processes with SU-8 resist. The degradation includes a 28% reduction in surface F atoms and significant increases in the surface roughness. In this paper, diamond-like carbon (DLC) films were investigated as an alternative material not only for coating but also for direct fabrication of nanoimprint templates. DLC films deposited on quartz templates in a plasma enhanced chemical vapor deposition system are shown to have better chemical and physical stability than FDTS. After the same 10 cycles of UV nanoimprints, the surface composition as well as the roughness of DLC films were found to be unchanged. The adhesion energy between the DLC surface and SU-8 is found to be smaller than that of FDTS despite the slightly higher total surface energy of DLC. DLC templates with 40?nm features were fabricated using e-beam lithography followed by Cr lift-off and reactive ion etching. UV nanoimprinting using the directly patterned DLC templates in SU-8 resist demonstrates good pattern transfer fidelity and easy template-resist separation. These results indicate that DLC is a promising material for fabricating durable templates for UV nanoimprint lithography.