非离子型表面活性剂结合金刚石膜电化学氧化的新型抛光后晶片清洗工艺

本文针对抛光后晶片的颗粒和有机污染物提出了一种新型清洗方法,它结合了非离子表面活性剂和掺硼金刚石膜（BDD）阳极电化学氧化的优势。非离子表面活性剂可以在抛光后晶片上形成一层保护膜,使晶片表面颗粒易于去除。颗粒去除对比实验结果通过金相显微镜观察得知,体积比为1%的非离子表面活性剂的颗粒去除效果最佳。然而表面活性剂保护膜本身属于有机物,它最终也需要被去除。金刚石膜阳极电化学氧化（BDD-EO）可以用来去除有机物,因为它可以有效降解有机物。三个有机污染物去除对比实验分别为：一是先用非离子表面活性剂再用BDD-EO,二是单纯用BDD-EO去除有机物,第三种是用传统RCA清洗技术。通过XPS检测结果表明,用BDD-EO清洗的晶片表面的有机残留明显少于传统RCA技术,并且晶片表面的非离子表面活性剂也可以有效去除。     

BDD 电化学结合表面活性剂的新型清洗方法

提出了一种新型抛光后的清洗方法,采用掺硼金刚石膜作阳极的电化学方法制备出氧化液,用其去除表面有机污染物,同时配合使用非离子表面活性剂去除表面固体颗粒.用金刚石膜电化学制备出氧化液,克服了单纯电化学氧化生成的强氧化性羟基自由基不稳定和寿命短等缺点,实现氧化能力持久保持.表面活性剂能有效地去除表面颗粒,清洗后Si片上会有残留物,氧化液可以将残留物去除.通过实验对比发现,这种新颖的清洗方法在颗粒和有机物去除上有很好的清洗效果,能够满足微电子工艺的发展需求.     

金刚石膜电化学清洗硅片表面有机沾污的研究

采用金刚石膜电极的电化学方式在专用水基清洗剂中不断产生强氧化剂过氧焦磷酸根离子(P2O4-8),并将此方式作为金刚石膜电化学清洗工艺步骤的第一步,用于氧化去除硅片表面的有机沾污.通过与RCA清洗进行对比实验,并应用X射线光电子谱和原子力显微镜进行清洗效果的检测,结果表明,本清洗工艺处理后的硅片表面有机碳含量更少,微粗糙度小,明显优于现有的RCA清洗工艺.     

金刚石膜电化学清洗硅片表面有机沾污的研究

采用金刚石膜电极的电化学方式在专用水基清洗剂中不断产生强氧化剂过氧焦磷酸根离子(P2O4-8),并将此方式作为金刚石膜电化学清洗工艺步骤的第一步,用于氧化去除硅片表面的有机沾污.通过与RCA清洗进行对比实验,并应用X射线光电子谱和原子力显微镜进行清洗效果的检测,结果表明,本清洗工艺处理后的硅片表面有机碳含量更少,微粗糙度小,明显优于现有的RCA清洗工艺.     

BDD电极电化学氧化清洗工艺氧化性研究

为了改进现有的RCA清洗法以及臭氧/过氧化氢湿式清洗技术,利用金刚石膜(BDD)电极的高级电化学氧化技术生成过氧化物氧化有机物,以实现简化清洗设备及节能环保。为研究金刚石膜电极的氧化能力,电解不同浓度的硫酸钾溶液,通过高锰酸钾滴定法进行氧化性的测量,研究原料浓度对生成过氧硫酸盐浓度的影响;通过添加KOH调节pH值,研究pH值对电化学制备过氧化物的影响,用该电化学氧化方法与RCA清洗法进行清洗效果对比。实验结果显示,金刚石膜电化学氧化能力可以通过阳极电解液浓度以及pH值的调整得到控制,清洗效果在Si片表面粗糙度方面明显优于传统的RCA清洗法,而且更加节能环保。     

用表面分析技术对显像管电极清洗工艺的研究

两种不同工艺清洗的显像管电子枪电极用 XPS、SEM 和 AES 进行了分析研究,发现用国内工艺清洗的电极表面大多程度不同的存在污染斑痕。污染物的主要成份是 Na、Cl、S、CaO、MgO 和 Al_2O_3,很可能是未彻底清洗掉的研磨剂残留物。分析表明,表面分析技术在显像管研制与生产中有可能发挥重要作用。     

金刚石膜电化学氧化液的制备及清洗技术研究

提出了一种采用电化学去除硅片表面有机物的新的清洗方法,用金刚石膜电极作为阳极,电化学氧化硫酸铵溶液生成稳定的强氧化溶液,电解液的氧化性通过间接碘量法测量。通过大量实验,优化初始电解液的浓度以及初始温度等因素,得到氧化强度最佳的电化学清洗液。用自制氧化液进行硅片表面有机物的清洗实验,并与传统的RCA清洗方法进行对比。通过XPS分析可知,采用新的电化学氧化溶液清洗后的硅片表面有机物去除效果明显优于对比实验样品。     

金刚石膜电极电化清洗中pH值的影响

利用硼掺杂金刚石膜电极在电解液中作阳极,通过控制各种相关条件使电解液中产生大量氢氧自由基和其他强氧化物质,将有机污染物氧化分解成小分子,甚至是CO2和H2O;同时配合专用清洗剂,极好地去除材料表面及狭缝中的固体颗粒和金属杂质,有效实现了被清洗表面的高度洁净化。通过实验分析了pH值的变化对电解液氧化性的影响,确定了最佳pH值为12.5。     

硅晶片表面污染物去除的关键工艺

硅晶片的清洗通常是在一个“过流(overflow)”清洗槽中进行,其中流过晶片的水流平均速度为1cm蛐s,而在晶片表面的速度则为零。清洗效率受到污染物从硅片表面扩散出并进入到水流速率的限制。报告了清洗效率的提高熏通过对初次将污染物扩散进停滞层的1min循环进行重复,然后“倾倒”清洗槽,从而去除大部分污染的停滞层。通过旋转晶片,并利用离心力去除更大部分的停滞层,每个清洗循环可将清洗效率再提高10倍眼1演。与目前的浸泡式清洗技术相比,本方法可以完全去除可溶性污染物,而使用的水量降低20倍。     

晶片清洗工艺的优化选取及其影响

本文提出了集成电路制作中值得注意的问题——“超微粒子效应”,论述了晶片清洗的优化选取方法及其对于去除超微粒子效应的影响,并阐明了超纯水洁净度在最佳表面清洗中的重要性.     

A new cleaning process for the metallic contaminants on a post-CMP wafer's surface

This paper presents a new cleaning process using boron-doped diamond(BDD) film anode electrochemical oxidation for metallic contaminants on polished silicon wafer surfaces.The BDD film anode electrochemical oxidation can efficiently prepare pyrophosphate peroxide,pyrophosphate peroxide can oxidize organic contaminants,and pyrophosphate peroxide is deoxidized into pyrophosphate.Pyrophosphate,a good complexing agent,can form a metal complex,which is a structure consisting of a copper ion,bonded to a surrou...     

非离子表面活性剂在阻挡层CMP后清洗中去除颗粒作用的研究

本文对非离子表面活性剂在阻挡层CMP后清洗中对颗粒的去除作用进行了研究。实验过程中,通过改变活性剂的浓度,在12inch多层铜布线片上进行了一系列的实验来确定最佳的清洗效果。然后对活性剂在缺陷控制、颗粒去除,以及活性剂在清洗过程中所起的负面作用等方面进行了讨论。实验结果表明,非离子表面活性剂在阻挡层CMP后清洗中根据浓度的不同所起的正面、负面作用不同,从而为阻挡层CMP后清洗过程中非离子表面活性剂的加入起到一定的指导作用。     

A lubrication model between the soft porous brush and rigid flat substrate for post-CMP cleaning

A 3D lubrication model between a soft porous brush and rigid flat surface in the post-CMP (chemical mechanical polishing) cleaning process for wafer or hard-disc surface is set up in this article. The mesh porous structure of the brush and the kinematic relations between the brush and the surface are taken into account. The flow governing equations for cleaning process are deduced with Newtonian fluids between the brush nodule and the substrate. The distributions of fluid pressure and hydrodynamic removal moment are calculated. The simulation results show that the fluid pressure has negative regions in inlet area. The removal force is depended on system parameter, location, time and particle size. The load and hydrodynamic moment increase with the increase of brush velocity and deflection of brush nodule, which is effective for cleaning. A low wafer rotation speed is recommended to keep the cleaning uniformity. The removal moment is increasing during the cleaning process. The hydrodynamic drag force decreases rapidly with decreasing of particle size. The models are coincident with the actual process and can be used as reference for designing a higher level cleaning process and the analysis of the formation of particle defect.     

A new cleaning process combining non-ionic surfactant with diamond film electrochemical oxidation for polished silicon wafers

This paper presents a new cleaning process for particle and organic contaminants on polished silicon wafer surfaces.It combines a non-ionic surfactant with boron-doped diamond(BDD) film anode electrochemical oxidation. The non-ionic surfactant is used to remove particles on the polished wafer's surface,because it can form a protective film on the surface,which makes particles easy to remove.The effects of particle removal comparative experiments were observed by metallographic microscopy,which showed tha...     

Megasonic cleaning: A new cleaning and drying system for use in semiconductor processing

A compact system for cleaning wafers in all stages of device manufacture has been developed which uses high frequency (0.8 to 1 MHZ) ultrasonic energy (hence, the term “Megasonic”) and a standard chemical solution which is not heated. The patented process effectively removes particles down to approximately 0.3 ym diameter simultaneously from the front and back surfaces, thin organic films, and many ionic impurities. After a brief water rinse, the wafers are dried in a hot air stream. The total cycle time is approximately 15 minutes, and at least 100 wafers can be cleaned in quartz or plastic carriers at the same time and without the need for loading or unloading. Megasonic cleaning has been applied to silicon wafers, ceramics, and photomasks, and has been used for photo- Paper presented at 20th Annual Electronic Materials Conference, University of California at Santa Barbara, CA, June 30, 1978.     

A visual sensing application to a climbing cleaning robot on the glass surface

This paper describes a visual sensing application to a climbing robot that provides cleaning service on the glass wall of high-rise buildings. The robot uses suction cups to stick on the glass, moves with a translation mechanism, and adjusts its orientation by rotating a flexible waist. A visual sensor, composed of an oriented CCD camera and two laser diodes, is used to measure the robot’s position and orientation relative to the window frame on the glass surface. The visual sensor is also used to locate the dirt spot to be cleaned. The mathematical model and the measure methodology of the visual sensing system are discussed. Experiments are performed to calibrate the visual sensor, measure the position and orientation of the robot, and measure the location of the dirty spot. The experimental results verify the effectiveness of the proposed approach.     

Effective cleaning process and its influence on surface roughness in anodic bonding for semiconductor device packaging

Wafer cleanliness and surface roughness play a paramount role in an anodic bonding process. Impurities and the roughness on the wafer surface result in unbonded areas which lead to fringes and Newton׳s rings. With an augment in surface roughness, lesser area will be in stroke thus making more pressure and voltage to be applied onto the wafers for better bonding. Eventually it became mandatory to choose the best cleaning process for the bonding technology that can substantially reduce the impurities and surface roughness. In this paper, we investigate the bonding of silicon/oxidized silicon on Pyrex (CORNING 7740) glass with respect to surface roughness and cleanliness of the wafers by performing three renowned cleaning processes such as degreasing, piranha, RCA 1& 2 (SC‐Standard Cleaning 1 and 2) and found that RCA compromises the best between the roughness and cleanliness. Studies were also extended to find out the effects of applied voltage and load on the bonded surface. It was observed for samples cleaned with RCA, an increase of 45% in maximum current and decrease of 75% in total bonding time with the applied load and voltage among all the cleaning techniques used. Three dimensional structures for pressure sensor application were successfully bonded by selecting the appropriate load and cleaning process. Atomic force microscopy analysis was done to investigate the surface roughness on silicon/oxidized silicon and Pyrex glass for different cleaning processes. Scanning electron microscopy and optical imaging were performed on the interface for the surface integrity of the bonded samples.     

低损耗太赫兹镀膜金属波导研究

在研究太赫兹波在镀膜二维平板金属波导传输时,损耗减小的机制和条件,发现只有TM 模式在大间隙的金属镀膜波导传播时,其损耗小于不镀膜的金属波导。利用射线光学方法分析波导尺寸、膜厚度以及膜折射率等参数对TM 模式损耗的影响,获得其损耗最低的优化结构参数。用转移矩阵理论对镀介质膜前后平板金属波导的损耗进行理论计算和分析,当介质为聚乙烯且厚度为0.06mm时,波导的损耗最小。所获结论对于太赫兹波导器件及太赫兹波低损耗波导研制具有较大的意义。