Showing posts with label Thin film and plasma physics. Show all posts
Showing posts with label Thin film and plasma physics. Show all posts

2007-05-08

Another notable figure in City Univerisity of Hongkong-Prof. Lee, Shuit-Tong(Hongkong)



Prof. Lee, Shuit-Tong
Member (Academican), Chinese Academy of Sciences

Professor (Chair) of Materials Science
Department of Physics & Materials Science

Director, Center Of Super-Diamond and Advanced Films (COSDAF)

BSc (CUHK), MS (Rochester), PhD (UBC)
Research Interest

Nanoscience and nanotechnology

Nanobiosensors

Nanooptoelectronics

Organic light emitting diode (OLED display technology

Nanodiamond

cBN and super-hard coatings

Surface science and modification



Awards

Hsun Lee Lecture Award, Institute of Metal Research, CAS, Shenyang, 2006

National Natural Science Award (2nd Class Award), State Council of the People's Republic of China, 2005

National Natural Science Award (2nd Class Award), State Council of the People's Republic of China, 2003

Croucher Senior Research Fellowship Award, Hong Kong, 2002

Humboldt Research Awards, Germany (from Alexander von Humboldt Foundation), 2001



Professional Roles

Editorship

Associate Editor, Applied Physics Letters (2006 - present)

Associate Editor, Diamond and Related Materials (1995 - present)

Regional Editor for Asia, Physica Status Solidi (2004 - present)

Editorial Board, Applied Physics Letters (2003 - 2005), Journal of Applied Physics (2003-2005), New Carbon Materials (1999 - present), Journal of Materials Science & Technology (2002 - 2005), Chinese Physical Society - Journal of Luminescence and Nanotechnolgy (2004 - present ) & Precision Engineering (2004 - present)

Advisory Editorial Board, Advanced Functional Materials (2000 - present) & Applied Nanoscience (2003 - present)

Guest Editor, Nanotechnology (Special issue, 2005)

Director, Key Laboratory of Nano-organic Optoelectronic Materials and Devices, TIPC, Chinese Academy of Sciences, Beijing, P.R. China (2001 - present)



Publications in Nature / Science

 


S. T. Lee, Y. Lifshitz, "The road to diamond wafers", Nature 424, 500 (2003).

D. D. D. Ma, C. S. Lee, F. C. K. Au, S. Y. Tong, S. T. Lee, "Small diameter silicon nanowire surface", Science 299,

1874-1877 (2003). The images of the paper were printed as the coverpage of the journal, Science (March 2003).

Y. Lifshitz, Th. Kohler, Th. Frauenheim, I. Guzmann, A. Hoffman, R. Q. Zhang, X. T. Zhou, S. T. Lee, "The mechanism of

diamond nucleation from energetic species", Science 297, 1531 (2002).

Y. Lifshitz, X. F. Duan, N. G. Shang, Q. Li, L. Wan, I. Bello, S. T. Lee, "Epitaxial diamond polytypes on silicon", Nature 412, 404 (2001).

S.T. Lee, H. Y. Peng, X. T. Zhou, N. Wang, C. S. Lee, I. Bello, and Y. Liftshitz, "A nucleation site and mechanism leading to epitaxial growth of diamond films", Science 287,104-106 (2000).

To see more detailed information about Prof. Lee Shuit-Tong, please go to this website:
http://www.cityu.edu.hk/cosdaf/Member%20Profiles/profilestlee.htm
Where you can find the lastest photo, and the members of his research group, as well as the condition about the Center Of Super-Diamond and Advanced Films(COSDAF).
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中文简介:
李述汤教授为材料化学及物理学家,是香港城市大学物理及材料科学系讲座教授。 1969年畢業於香港中文大學化學系,1971年在美國 Rochester 大學化學系獲碩士學位,1974年於加拿大 British Columbia 大學化學系獲博士學位。1969年毕业于香港中文大学化学系,1971年在美国 Rochester大学化学系获硕士学位,1974年于加拿大BritishColumbia大学化学系获博士学位。 1974年至1976在美國加州大學伯克力分校做博士後研究,1976年至1994年在美國Eastman Kodak公司任研究員,1994年到香港城市大學工作至今,現任香港城市大學超金剛石及先進薄膜研究中心主任,並兼任中國科學院理化技術研究所研究員和納米有機光電子實驗室主任。1974年至1976在美国加州大学伯克力分校做博士后研究,1976年至1994年在美国Eastman Kodak公司任研究员,1994年到香港城市大学工作至今,现任香港城市大学超金刚石及先进薄膜研究中心主任,并兼任中国科学院理化技术研究所研究员和纳米有机光电子实验室主任。

  李教授長期致力於光電子材料,如納米材料、金剛石和相關材料以及有機電致發光材料領域的研究。  李教授长期致力于光电子材料,如纳米材料、金刚石和相关材料以及有机电致发光材料领域的研究。 在《Science》、《Nature》等國際重要期刊發表論文550餘篇,獲美國專利15項,撰寫專著6部,論文被他人引用5000餘次。在《Science》、《Nature》等国际重要期刊发表论文550余篇,获美国专利15项,撰写专著6部,论文被他人引用5000余次。 2001至2005年相繼榮獲德國洪堡基金會研究成就獎 (Humboldt Research Award)、香港裘槎基金會高級研究成就獎(Croucher Senior Research Fellowship) 和2項中國國家自然科學二等獎 (State Natural Science Award, 2002 & 2005)。2001至2005年相继荣获德国洪堡基金会研究成就奖 (HumboldtResearchAward)、香港裘槎基金会高级研究成就奖(CroucherSeniorResearchFellowship) 和2项中国国家自然科学二等奖(StateNaturalScienceAward,2002&2005)。 目前擔任多種國際期刊的編輯及編委,包括《Applied Physics Letters》和《Diamond & Related Materials》的副總編輯、《Physica Status Solidi》國際雜誌亞太區主編。目前担任多种国际期刊的编辑及编委,包括《Applied PhysicsLetters》和《Diamond&RelatedMaterials》的副总编辑、《PhysicaStatusSolidi》国际杂志亚太区主编。 2005年12月榮膺為中國科學院院士。2005年12月荣膺为中国科学院院士。

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2007-05-07

The Working Principle of Plasma Sprayer ( 等离子喷涂设备的工作原理)

等离子喷涂技术是继火焰喷涂之后大力发展起来的一种新型多用途的精密喷涂方法.它包括大气等离子喷涂,保护气氛等离子喷涂,真空等离子喷涂和水稳等离子喷涂。 等离子体喷涂具有如下优点:①超高温特性,便于进行高熔点材料的喷涂。②喷射粒子的速度高,涂层致密,粘结强度高。③由于使用惰性气体作为工作气体,所以喷涂材料不易氧化。

其工作原理如下:

<1>等离子的形成(以N2为例):



0°k时,N2分子的两个原子程哑铃形,仅在x,y,z方向上平动;

大于10°k时,开始旋转运动;

大于10000°k时,原子间产生振动,分子与分子间碰撞,则分子会发生离解变为单原子:

N2+Ud——>N+N 其中 Ud为离解能

温度再升高,原子会发生电离: N+Ui——>N++e 其中 Ui为电离能

气体电离后,在空间不仅有原子,还有正离子和自由电子,这种状态就叫等离子体。

等离子体可分为三大类:①高温高压等离子体,电离度100%,温度可达几亿度,用于核聚变的研究;②低温低压等离子体,电离度不足1%,温度仅为50~250度;③高温低压等离子体,约有1%以上的气体被电离,具有几万度的温度。离子、自由电子、未电离的原子的动能接近于热平衡。热喷涂所利用的正是这类等离子体。

<2>喷涂原理:

等离子喷涂原理如图2所示。


等离子喷涂是利用等离子弧进行的,离子弧是压缩电弧,与自由电弧项比较,其弧柱细,电流密度大,气体电离度高,因此具有温度高,能量集中,弧稳定性好等特点。

按接电方法不同,等离子弧有三种形式:

①非转移弧:指在阴极和喷嘴之间所产生的等离子弧。这种情况正极接在喷嘴上,工件不带电,在阴极和喷嘴的内壁之间产生电弧,工作气体通过阴极和喷嘴之间的电弧而被加热,造成全部或部分电离,然后由喷嘴喷出形成等离子火焰(或叫等离子射流)。

等离子喷涂采用的就是这类等离子弧。

②转移弧:电弧离开喷枪转移到被加工零件上的等离子弧。这种情况喷嘴不接电源,工件接正极,电弧飞越喷枪的阴极和阳极(工件)之间,工作气体围绕着电弧送入,然后从喷嘴喷出。

等离子切割,等离子弧焊接,等离子弧冶炼使用的是这类等离子弧。

③联合弧:非转移弧引燃转移弧并加热金属粉末,转移弧加热工件使其表面产生熔池。这种情况喷嘴,工件均接在正极。

等离子喷焊采用这种等离子弧。

进行等离子喷涂时,首先在阴极和阳极(喷嘴)之间产生一直流电弧,该电弧把导入的工作气体加热电离成高温等离子体,并从喷嘴喷出,形成等离子焰,等离子焰的温度很高,其中心温度可达30000°k,喷嘴出口的温度可达

; 15000~20000°k。焰流速度在喷嘴出口处

可达1000~2000m/s,但迅衰减。粉末由送

粉气送入火焰中被熔化,并由焰流加速得到高于150m/s的速度,喷射到基体材料上形成膜。

图3等离子焰流温度分布


<3>等离子喷涂设备:等离子喷涂设备主要包括:

①喷枪:实际上是一个非转移弧等离子发生器,是最关键的部件,其上集中了整个系统的电,气,粉,水等。

②电源:用以供给喷枪直流电。通常为全波硅整流装置。

③送粉器:用来贮存喷涂粉末并按工艺要求向喷枪输送粉末的装置。

④热交换器:主要用以使喷枪获得有效的冷却,达到使喷嘴延寿的目的。

⑤供气系统:包括工作气和送粉气的供给系统。

⑥控制框:用于对水,电、气、粉的调节和控制。

<4>等离子喷涂工艺:

在等离子喷涂过程中,影响涂层质量的工艺参数很多,主要有:

①等离子气体:气体的选择原则主要根据是可用性和经济性,N2气便宜,且离子焰热焓高,传热快,利于粉末的加热和熔化,但对于易发生氮化反应的粉末或基体则不可采用。Ar气电离电位较低,等离子弧稳定且易于引燃,弧焰较短,适于小件或薄件的喷涂,此外Ar气还有很好的保护作用,但Ar气的热焓低,价格昂贵。

气体流量大小直接影响等离子焰流的热焓和流速,从而影响喷涂效率,涂层气孔率和结合力等。流量过高,则气体会从等离子射流中带走有用的热,并使喷涂粒子的速度升高,减少了喷涂粒子在等离子火焰中的“滞留”时间,导致粒子达不到变形所必要的半熔化或塑性状态,结果是涂层粘接强度、密度和硬度都较差,沉积速率也会显著降低;相反,则会使电弧电压值不适当,并大大降低喷射粒子的速度。极端情况下,会引起喷涂材料过热,造成喷涂材料过度熔化或汽化,引起熔融的粉末粒子在喷嘴或粉末喷口聚集,然后以较大球状沉积到涂层中,形成大的空穴。

②电弧的功率:

电弧功率太高,电弧温度升高,更多的气体将转变成为等离子体,在大功率、低工作气体流量的情况下,几乎全部工作气体都转变为活性等粒子流,等粒子火焰温度也很高,这可能使一些喷涂材料气化并引起涂层成分改变,喷涂材料的蒸汽在基体与涂层之间或涂层的叠层之间凝聚引起粘接不良。此外还可能使喷嘴和电极烧蚀。

而电弧功率太低,则得到部分离子气体和温度较低的等离子火焰,又会引起粒子加热不足,涂层的粘结强度,硬度和沉积效率较低。

③供粉

供粉速度必须与输入功率相适应,过大,会出现生粉(未熔化),导致喷涂效率降低;过低,粉末氧化严重,并造成基体过热。

送料位置也会影响涂层结构和喷涂效率,一般来说,粉末必须送至焰心才能使粉末获得最好的加热和最高的速度。

④喷涂距离和喷涂角

喷枪到工件的距离影响喷涂粒子和基体撞击时的速度和温度,涂层的特征和喷涂材料对喷涂距离很敏感。

喷涂距离过大,粉粒的温度和速度均将下降,结合力、气孔、喷涂效率都会明显下降;过小,会使基体温升过高,基体和涂层氧化,影响涂层的结合。在机体温升允许的情况下,喷距适当小些为好。

喷涂角:指的是焰流轴线与被喷涂工件表面之间的角度。该角小于45度时,由于“阴影效应”的影响,涂层结构会恶化形成空穴,导致涂层疏松。

⑤喷枪与工件的相对运动速度

喷枪的移动速度应保证涂层平坦,不出线喷涂脊背的痕迹。也就是说,每个行程的宽度之间应充分搭叠,在满足上述要求前提下,喷涂操作时,一般采用较高的喷枪移动速度,这样可防止产生局部热点和表面氧化。

⑥基体温度控制

较理想的喷涂工件是在喷涂前把工件预热到喷涂过程要达到的温度,然后在喷涂过程中对工件采用喷气冷却的措施,使其保持原来的温度。

近几年来,在等离子喷涂的基础上又发展了几种新的等离子喷涂技术,如:

1)真空等离子喷涂(又叫低压等离子喷涂)

真空等离子喷涂是在气氛可控的,4~40Kpa的密封室内进行喷涂的技术。

因为工作气体等离子化后,是在低压气氛中边膨胀体积边喷出的,所以喷流速度是超音速的,而且非常适合于对氧化高度敏感的材料。

2)水稳等离子喷涂

前面说的等离子喷涂的工作介质都是气体,而这种方法的工作介质不是气而是水,它是一种高功率或高速等离子喷涂的方法,其工作原理是:

喷枪内通入高压水流,并在枪筒内壁形成涡流,这时,在枪体后部的阴极和枪体前部的旋转阳极间产生直流电弧,使枪筒内壁表面的一部分蒸发、分解,变成等离子态,产生连续的等离子弧。由于旋转涡流水的聚束作用,其能量密度提高,燃烧稳定,因此,可喷涂高熔点材料,特别是氧化物陶瓷,喷涂效率非常高。

http://www2.zzu.edu.cn/classware/clkx/menu/biaomian/content/chap5/5-3.htm


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2007-05-05

An Introduction of Professor Paul K Chu(朱剑豪教授)(City University of Hong Kong)


Paul K Chu was born in Hong Kong and attended both primary and secondary school at St. Joseph's Anglo-Chinese School. He went to the United States at the age of 17 and was accepted to the honors program at The Ohio State University in Columbus, Ohio. He was awarded the prestigious American Chemical Society (ACS) Student Fellowship and worked at New England Aquarium in Boston on trace metal analysis of seawater during the summer of 1976. He received his BS in mathematics (cum laude and phi beta kappa) from Ohio State in 1977 and went to graduate school at Cornell University in Ithaca, New York. He won the DuPont teaching award as a teaching assistant at Cornell in 1978 and joined the research group of Prof. George H Morrison of the Department of Chemistry. Prof. Morrison was one of the prominent figures in analytical chemistry having been involved with the Apollo moon expedition programs. Prof. Morrison was a winner of the ACS Analytical Chemistry Award and Editor-in-Chief of Analytical Chemistry, the premier journal in analytical chemistry published by the American Chemical Society. Under the supervision of Prof. Morrison and Prof. James W Mayer of the Department of Materials Science & Engineering at Cornell, Paul conducted research on ion beam processing and characterization of semiconductors and received his MS and PhD in chemistry in 1979 and 1982, respectively.

Upon graduation, he joined Charles Evans & Associates in California which was a small company at that time but later became one of the biggest companies in the late 1980s in materials characterization. During the eight year span from 1982 to 1990, Paul was promoted 4 times and became one of the most recognized international figures in the area of secondary ion mass spectrometry (SIMS). He was one of the organizers of the SIMS-VII conference in Monterey, California in 1989, and wrote the chapter on SIMS in “Encyclopedia of Materials Characterization”. In 1990, with the help of the parent company, Paul started his first company, Evans Asia, in Hong Kong / Taiwan / Singapore / China specializing in materials characterization and analytical equipment.

In 1996, he joined City University of Hong Kong as a faculty member and ventured into the new area of plasma immersion ion implantation (PIII). He obtained financial support from City University of Hong Kong, University of Hong Kong, Hong Kong University of Science & Technology, as well as Hong Kong Research Grants Council (RGC) to establish the Plasma Laboratory in City University of Hong Kong. The Plasma Laboratory has emerged to be one of the most well known and versatile PIII facilities in the world, and Paul is recognized as one of the leading international figures in plasma-based materials engineering. He is the elected Chairman of the International Plasma-Based Ion Implantation Executive Committee which organizes the biannual International Workshop on Plasma-Based Ion Implantation and Deposition (PBII&D). He is also a member of the Ion Implantation Technology (IIT) International (Governing) Committee that organizes the biannual International Conference on Ion Implantation Technology.

Paul joined IEEE in 1997, became a senior member in 1999, and was elected Fellow of the Institute of Electrical and Electronics Engineers in 2003 for his contributions to the understanding of plasma immersion ion implantation and deposition. He is very active in the IEEE serving as a member of the international advisory board of the IEEE International Conference on Plasma Science (ICOPS) from 1996 to 1998, Guest Editor of 3 special issues of IEEE Transactions on Plasma Science [vol. 34, no. 4 (2006); vol. 33, no. 4 (2005); vol. 32, no. 2 (2004)], Senior Editor of IEEE Transactions on Plasma Science since 2006, and an executive committee (ExCom) member of the IEEE Plasma Science and Application Committee (PSAC) since 2007. Paul joined AVS (American Vacuum Society) in 2002 and was elected Fellow of AVS in 2006 for his contributions to plasma science and surface engineering of materials and industrial components. He is also Fellow of the Hong Kong Institution of Engineers (FHKIE). Paul is an elected scientific member of the Böhmishe Physical Society (BPS) as well as member of the American Chemical Society (ACS) and Materials Research Society (MRS). Locally, he is a technical advisor to the National 863 Materials & Surface Engineering R&D Center in Shenzhen, China, advisor to Shenzhen Polytechnic, and member of the standing committee of the Chinese Mechanical Engineering Society. He is an associate editor of International Journal of Plasma Science and Engineering and has been a member of the Editorial Board of Materials Science and Engineering: Reports since 2005, International Journal of Molecular Engineering since 2006, Surface and Interface Analysis since 2006, and Recent Patents on Material Science since 2007. He was a member of the Editorial Board of Nuclear Instruments and Methods in Physics Research B: Beam Interactions with Materials and Atoms from 2000 to 2006 and guest editor of the PBII&D2005 special issue published in Surface and Coatings Technology [vol. 201, no. 15 (2007)]. He was a co-chair / organizer of Symposium GG: Ion-Beam-Based Nanofabrication in the MRS Spring Meeting in San Francisco in 2007. He was a member of the Hong Kong Research Grants Council (RGC) Engineering Panel from 2000 to 2006.

Academically, in addition to being Professor (Chair) of Materials Engineering in the Department of Physics & Materials Science in City University of Hong Kong, he holds or has held advisory / visiting professorship in ten universities and research institutes in China: Institute of Microelectronics in Peking University (Beijing), Department of Materials Science in Fudan University (Shanghai), Department of Materials Science and Engineering in Shanghai Jiaotong University (Shanghai), Department of Materials Engineering in Southwest Jiaotong University (Chengdu), School of Materials Science and Engineering in Harbin Institute of Technology (Harbin), Department of Physics in Nanjing University (Nanjing), College of Materials Engineering in Jiamusi University (Jiamusi), Southwestern Institute of Physics (Chengdu), Shanghai Institute of Ceramics of The Chinese Academy of Sciences, and Shanghai Institute of Microsystem and Information Technology of The Chinese Academy of Sciences. He has established a joint PhD program with the University of Sydney in Australia in which students in his research group in City University of Hong Kong or School of Physics in the University of Sydney receive PhD degrees from both universities upon graduation. He also participates in a similar joint PhD program between City University of Hong Kong and Tsinghua University, China. Paul's teaching credentials are quite impressive. He won the DuPont Teaching Award at Cornell University. At City University of Hong Kong, he has been voted “best lecturer” and “best presenter” by students in his department and short listed for the Teaching Excellence Award. He has taught many short courses and professional seminars on materials characterization and processing in universities and companies in the US, Canada, China, Japan, Korea, Taiwan, and Singapore.

Paul's research activities are quite diverse, spanning plasma science and engineering, ion implantation, surface modification, functional thin films, biomaterials, semiconductor materials and processing, optoelectronic materials, as well as nanotechnology. He is the editor of two books on biomaterials and plasma engineering. He has published more than 10 book chapters, 550 papers in international refereed journals, and 550 international conference papers, many of which invited or plenary. His innovative works on light emission from plasma-implanted silicon, novel silicon-on-insulator (SOI) materials, as well as the enhancement of surface bioactivity and blood compatibility of biomaterials using plasma, chemical, and optical techniques have been featured many times in magazines and electronic journals. He has obtained US$10 million in research funding from agencies and companies in Hong Kong, Australia, China, Germany, Switzerland, and the US. Two of his research projects were awarded the "Excellent" rating by the City University of Hong Kong and Hong Kong Research Grants Council and he was the winner of the Second Best Paper Award in the IEEE International SOI Conference.

Paul is also heavily involved in applied research and industrial applications. His innovations on plasma processing and instrumentation have led to 8 United States patents and 3 Chinese patents. He founded his second company, Plasma Technology Ltd., in 1998 and co-founded his third company, Chengdu Pulsetech Electrical Co. Ltd., in 2001 to address the Chinese and other markets. The two companies specialize in the development of commercial plasma-based technologies as well as production of hardware such as ion sources, plasma implanters, and power supplies while also providing consultation to the industry. He was awarded the Applied Research Certificate of Merits for innovations in plasma instrumentation and power supplies and Hong Kong Awards for Industry: Technological Achievement Certificate of Merit for the development of plasma implantation and deposition technologies. Internationally, Paul’s achievement was instrumental to the establishment of Silicon Genesis Corporation in the Silicon Valley in California. Paul's research group produced the world’s first 100mm and 150mm silicon-on-insulator (SOI) wafers by plasma immersion ion implantation and ion-cutting, leading to multi-million dollar capital infusion from Intel, Applied Materials, MEMC, Komatsu, H&Q and other VCs into Silicon Genesis. The invention was featured on the cover of the 40th anniversary issue of Solid State Technology as the representative technology from Hong Kong.

Paul participates actively in amateur sports and is Honorary Manager of the City University of Hong Kong varsity badminton and swimming teams. He has won men's singles, men's doubles, mixed doubles, and teams events in CityU Student/Staff badminton tournaments. In swimming, he holds all of the City University of Hong Kong staff records in breast stroke and butterfly and has won more than 100 medals in Hong Kong masters swimming competitions.

For more information, please go to this website:
http://www.cityu.edu.hk/ap/plasma/Paul%20Chu/paul_chu.htm

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2007-04-28

High Power Pulsed Magnetron Sputtering (HPPMS)(excerpt)


The following text was excerpt from the webpage:
http://www.ifm.liu.se/plasma/reshppms.html
Glow discharge thin film deposition processes are technologically very important and are extensively used for industrial production of layers as well as in materials research, especially in facilitating in the creation of new advanced materials. Unlike evaporative techniques glow discharge plasmas can be tailored to obtain impinging particles with energies comparable to typical surface and molecular binding energies. This in turn gives yields increased adatom mobility as well as increased surface chemical reaction rates which give rise to epitaxial growth at reduced temperatures and synthesis of chemically metastable materials. Compound formation, in which the reactivity between constituents is the rate-limiting step also becomes easier. For instance, dissociation can occur as a result of energetic plasma processes, such as electron, ion, and photon irradiation.

An even greater advantage can be achieved if the deposition material itself is ionized (ionized sputtering). In this case the material can be accelerated to desired energies and guided in direction, using electrical or magnetical fields, to facilitate e.g. film substrate intermixing, nano- and microstructural modifications, and creation of metastable phases.Due to this interest in achieving a deposition flux in the form of ions rather than neutrals, several new ionized physical vapor deposition (IPVD) techniques have emerged giving this possibility [1]. These techniques are all based on the formation of very high plasma densities which makes it virtually impossible for the deposition atoms to escape from the vapor generation zone without becoming ionized by energetic electrons. The first IPVD systems consisted of a magnetron cathode for physical sputtering of atoms and a secondary inductively coupled plasma (ICP) discharge[2], by a secondary microwave driven discharge[3], or by shaping the cathode target in a particular way in order to confine the electrons, referred to as hollow cathode magnetron discharge[4]. High-power pulsed dc magnetrons in unipolar mode have been proposed for highly ionized sputtering[5,6]. In a conventional dc magnetron the power density is limited by the thermal load on the target, since most of the energy of the positive ions accelerated to the target is transformed into heat. In unipolar pulsing the power supply operates at low (or zero) power level and then pulses to a significantly higher level for a short period each cycle. When the peak power densities exceed 1 kW/cm2 we refer to the process as HPPMS. The peak power density is generally in the range 1-3 kW/cm2 at peak target voltage in the range 300-1500 V. Thus substantial increase in the instantaneous plasma density is achieved without increasing the thermal load of the target. The pulsed magnetron has been demonstrated for use in high-aspect-ratio filling applications and improved thickness homogeneity of the deposited films compared to conventional dc magnetrons[5].For a list of our recent publication in this field see the publication list.
[1] See for example: Ionized Physical Vapor Deposition, Ed. by JA Hopwood (Academic Press, London, 2000) or JM Schneider, SL Rohde, WD Sproul, and A Matthews, Recent Developments in Plasma Assisted Physical Vapour Deposition, Journal of Physics D 33, 2000, R173.
[2] Magnetron sputter deposition with high levels of metal ionization, S.M. Rossnagel and J. Hopwood, Appl. Phys. Lett. 63 (1993) 3285.
[3] Development of a cylindrical DC magnetron sputtering apparatus assisted by microwave plasma, A. Yonesu, H. Takemoto, M. Hirata, and Y. Yamashiro, Vacuum 66 (2002) 275.
[4] Hollow cathode magnetron, Z. Wang and S.A. Cohen, J. Vac. Sci. Technol. A 17 (1999) 77.
[5] novel pulsed magnetron sputter technique utilizing very high target power densities, V. Kouznetsov, K. Macák, J.M. Schneider, U. Helmersson, and I. Petrov, Surface and Coatings Technology 122 (1999) 290.

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the Plasma & Coatings Physics division(Linköping University)


Jan-Eric Sundgren, Senior Vice President at Volvo AB, is discussing the possible benefits for Volvo to use the HIPIMS-technology.
The Plasma & Coatings Physics group is a division at the Department of Physics and Measurement Technology (IFM), Linköping University, Sweden. Our research concerns investigations of methods for growth of thin films (using sputtering techniques), as well as development of coatings for various applications. The group was formed from, and still works in close collaboration with, the Thin Film Physics group.

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2007-04-22

A website help you solve some FAQ!


I find out a website which introduce some FAQ (Frequently Asked Questions). Its purpose is to provide good answers to questions that have been discussed often in sci.physics and related usenet newsgroups. The articles in this FAQ are based on those discussions and on information from good reference sources. That does not mean that they are always perfect and complete. If you have corrections, updates or additional points to make please send an email to the editor,
document.write(donsAdrs()) Don Koks (his cv is here). If you want to write up an article following a news group discussion about a subject not yet covered here then feel free to send it to the editor, but please do not use this address to ask new questions.

The address is as follows:


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