Technical use of compact micro-onde devices

Due to the very small size of a COMIC (Compact MIcrowave and Coaxial) device [P. Sortais, T. Lamy, J. Me?dard, J. Angot, L. Latrasse, and T. Thuillier, Rev. Sci. Instrum. 81, 02B31 (2010)] it is possible to install such plasma or ion source inside very different technical environments. New applications of such a device are presented, mainly for industrial applications. We have now designed ion sources for highly focused ion beam devices, ion beam machining ion guns, or thin film deposition machines. We will mainly present new capabilities opened by the use of a multi-beam system for thin film deposition based on sputtering by medium energy ion beams. With the new concept of multi-beam sputtering (MBS), it is possible to open new possibilities concerning the ion beam sputtering (IBS) technology, especially for large size deposition of high uniformity thin films. By the use of multi-spots of evaporation, each one corresponding to an independent tuning of an individual COMIC ion source, it will be very easy to co-evaporate different components.     

An Ion-Beam Apparatus for the Formation of Oxide Films by the Oxygen Ion Sputtering Technique

A source of oxygen ions operating on the basis of a two-stage self-sustained discharge with a cold hollow cathode is used in an apparatus for target sputtering. An assisting ion flow is produced by a Kaufmann open-end ion source of the Hall type. The sources are mounted in a vacuum volume and are operated simultaneously. Tantalum oxide, silicon oxide, and barium titanate films obtained by using an assisting ion flow are more homogeneous and have a narrower film–substrate transition layer and a composition closer to the stoichiometric one than films obtained under identical conditions but without an ion-flow assistance.     

Comparison of ion beam sputtered chromium and iridium films for electron microscopy applications

The structure and composition of thin, conductive metallic films of chromium and iridium that are typical of the coatings used for electron microscopy is described. The purpose of this study was to determine the grain size and composition of the films deposited, with thicknesses of 1 nm, 2.5 nm, and 5 nm, onto amorphous carbon films using ion beam sputtering with argon as the sputtering gas. A comparison between chromium films deposited under conditions of liquid nitrogen (LN) trapping or of no trapping revealed slight differences in their microstructure. As expected, the grain size of the films increased with the thickness, and the average grain sizes varied between 10 and 25 nm. Grain size was also found to depend on the source of ion beam energy; the correlation between grain size and beam energy was more pronounced in the iridium films than in the chromium films. This effect was greater when the deposition chamber was not LN trapped. As the ion beam energy increased from 18 W to 24 W, there was a corresponding increase in grain size in some of the films. Although transmission electron diffraction analysis indicated the presence of about 5% chromium oxide in the chromium films, no oxide was detected in the iridium films.     

Structure analysis of sputter-coated and ion-beam sputter-coated films: a comparative study

Gold, platinum and tungsten films were deposited by low energy input (7 mA, 450 V), or high deposition rate (80 mA, 1500 V), diode sputter coating and by ion beam sputter coating. Film structures on Formvar coated grids and on the surface of coated erythrocytes, resin embedded, sectioned, and recorded at high magnification in a TEM were compared using computer-assisted measurements and analysis of film thickness and grain size. The average grain size of the thinnest gold and platinum films was relatively independent of the mode or rate of deposition but as the film thickness increased, significant differences in grain size and film structure were observed. Thick platinum or gold films deposited by low energy input sputter coating contained large grain size and electron transparent cracks; however, more even films with narrower cracks but larger grain size were produced at high deposition rates. Ion beam sputter coated gold had relatively large grain size in 10 nm thick films, but beyond this thickness the grains coalesced to form a continuous film. Platinum films deposited by ion beam sputter coating were even and free of electron transparent cracks and had a very small grain size (1–2 nm), which was relatively independent of the film thickness. Tungsten deposition either by low energy input or ion beam sputter coating resulted in fine grained even films which were free of electron transparent cracks. Such films remained granular in substructure and had a grain size of about 1 nm which was relatively independent of film thickness. Tungsten films produced at high deposition rates were of poorer quality. We conclude that thick diode sputter coated platinum and gold films are best deposited at high deposition rates provided the specimens are not heat sensitive, the improvement in film structure being more significant than the slight increase in grain size. Thick diode or ion beam sputter coated gold films should be suitable for low resolution SEM, and thin discontinuous gold films for medium resolution SEM. Diode sputter coated platinum should be suitable for medium resolution SEM and ion beam sputter coated platinum for medium and some high resolution SEM. 1–5 nm thick tungsten films, deposited by low energy input or ion beam sputter coating should be suitable for high resolution SEM, particularly where contrast is of less importance than resolution.     

Ion beam sputtering: an improved method of metal coating SEM samples and shadowing CTEM samples

An apparatus to ion beam sputter-coat SEM samples has recently become available. The equipment uses a small saddle-field ion source to sputter deposit metals on to samples. This eliminates the surface artefacts seen at high magnifications on samples coated by diode sputtering. Ion beam sputtering has also been used to shadow samples for CTEM and has been found to result in a grain size of 1.2 nm. This technique isolates the specimens from the high-energy plasma and thus little or no heating of the sample occurs. The removal of the SEM samples from the high-energy plasma and the use of diffusion pump vacuum conditions to prevent contamination are suggested as reasons for the improved coating quality over diode sputtering.     

Influence of ion source configuration and its operation parameters on the target sputtering and implantation process

In the work, investigation of the features and operation regimes of sputter enhanced ion-plasma source are presented. The source is based on the target sputtering with the dense plasma formed in the crossed electric and magnetic fields. It allows operation with noble or reactive gases at low pressure discharge regimes, and, the resulting ion beam is the mixture of ions from the working gas and sputtering target. Any conductive material, such as metals, alloys, or compounds, can be used as the sputtering target. Effectiveness of target sputtering process with the plasma was investigated dependently on the gun geometry, plasma parameters, and the target bias voltage. With the applied accelerating voltage from 0 to 20 kV, the source can be operated in regimes of thin film deposition, ion-beam mixing, and ion implantation. Multi-component ion beam implantation was applied to α-Fe, which leads to the surface hardness increasing from 2 GPa in the initial condition up to 3.5 GPa in case of combined N(2)-C implantation. Projected range of the implanted elements is up to 20 nm with the implantation energy 20 keV that was obtained with XPS depth profiling.     

负偏压对DLC薄膜结构和摩擦学性能的影响

采用离子束溅射沉积镀膜法制备了DLC薄膜,研究了偏压对薄膜性能的影响。通过原子力显微镜(AFM)和拉曼光谱对DLC薄膜的表面形貌以及内部结构进行了分析表征。并用UTM-2摩擦磨损仪对其摩擦学性能进行了测试。结果表明,利用离子束溅射沉积制备的DLC薄膜具有良好的减摩抗磨性能。随着偏压的增加薄膜的摩擦因数先减小后增加,在-150 V偏压时,薄膜的摩擦学性能最好。     

An installation for magnetron deposition of getter coatings in narrow-aperture chambers

An installation for magnetron sputtering of thin-film coatings has been designed to deposit getter films in extended vacuum structures with a complex aperture. A solenoid used in the installation (diameter, 600 mm; length, 6000 mm; and maximum field, 800 G) makes it possible to deposit materials by sputtering onto internal walls in any type of vacuum chambers employed in modern accelerators. Results of deposition of a TiZrV getter coating in narrow-aperture aluminum vacuum chambers that will be mounted in the damping sections of a PETRA III synchrotron radiation source by DESY (Hamburg, Germany) are presented. The atomic composition and the homogeneity of the film along its length have been investigated on a channel for SR-XRF analysis at the Budker Institute of Nuclear Physics.     

Ion beam-sputtered and magnetron-sputtered thin films on cytoskeletons: A high-resolution tem study

A comparison of ion beam-sputtered and magnetron-sputtered thin platinum (Pt) and tungsten (W) films was made. Cytoskeletons from detergent extracted glioma cells grown on gold grids were coated with Pt or W at thicknesses of 1, 1.5, and 2.5 nm. Transmission electron micrographs were taken at high magnification and the granularity of the metal films was evaluated both on the Formvar film and the filaments of the cytoskeleton. In order to make a comparison between the two deposition methods, the metal deposition rate must be equal when corresponding thicknesses are made. Since ion beam sputtering generally is a slower process than magnetron sputtering, an increased target to specimen distance was necessary with the latter technique. This resulted in a coarser granularity of the W films as compared with the ion beam sputtered. The Pt, however, showed no marked difference between the two techniques at equal deposition rates. The study also demonstrated that varying the deposition rate caused differences in the granularity of the magnetron-sputtered Pt and W films, even if the voltage of the target was kept constant. Decreasing the target to specimen distance which increased the deposition rate resulted in a finer granularity of both the Pt and the W films. At the highest deposition rate the granularity of both the Pt and W films was comparable with the granularity of the ion beam-sputtered films.     

荷能离子束沉积的氧化物薄膜光学性质

报道在不加热的基底上,由双离子束溅射或离子辅助的电子束蒸发技术制造的ＺｒＯ２ 和ＴｉＯ２ 单层薄膜的光学性质,并提供了工艺参数和离子束设备的详情。这两种荷能离子束工艺已被用于光学多层膜,如减反射膜和短波通滤光片的制备。     

基于离子束溅射Ta2O5薄膜的紫外吸收膜技术

为获得高性能紫外激光薄膜元件,急需研制紫外高反射吸收薄膜,实现吸收损耗的精确测量。本文采用离子束溅射技术,通过调控氧气流量实现了具有不同吸收的Ta_2O_5薄膜的制备。以Ta_2O_5薄膜作为高折射率材料,设计了355nm的紫外高反射吸收薄膜。采用离子束溅射沉积技术,在熔融石英基底上制备了355nm的吸收薄膜,对于A=5%的紫外吸收光谱,在355nm的透射率、反射率和吸收率分别为0.1%,95.0%和4.9%;对于A=12%的紫外吸收光谱,在355nm的透射率、反射率和吸收率分别为0.1%,87.4%和12.5%。实验结果表明,采用离子束溅射沉积技术,可以实现不同吸收率的355nm高反射吸收薄膜的制备,对于基于光热偏转测量技术的紫外光学薄膜弱吸收测量仪的定标具有重要的意义。     

Thermal stability of Ti and Pt nanowires manufactured by Ga+ focused ion beam

Ti and Pt nanowires have been produced by ultra high‐vacuum molecular beam epitaxy deposition of Ti thin films and focused ion beam (FIB) deposition of Pt thin films, followed by cross‐sectional FIB sputtering to form electron‐transparent nanowires. The thermal stability of the nanowires has been investigated by in situ thermal cycling in a transmission electron microscope. Epitaxial single crystal Ti nanowires on (0001)Al₂O₃ substrates are microstructurally stable up to 550–600 °C, above which limited dislocation motion is activated shortly before the Ti‐wires oxidize. The amorphous FIB‐deposited Pt wires are stable up to 580–650 °C where partial crystallization is observed in vacuum. Faceted nanoparticles grow on the wire surface, growing into free space by surface diffusion and minimizing contact area with the underlying wire. The particles are face‐centred cubic (fcc) Pt with some dissolved Ga. Continued heating results in particle spheroidization, coalescence and growth, retaining the fcc structure.     

高能离子束辅助沉积制备钛纳米膜

用离子束溅射沉积和高能离子束辅助沉积方法制备了具有择尤性的钛纳米薄膜,并采用原子力显微镜、X射线衍射仪和俄歇电子谱仪研究了试样表面预处理、离子束流和温度等离子束工艺参数对钛薄膜结构的影响。结果表明：离子束溅射沉积的钛膜在[002]和[102]晶向上呈现出明显的择尤生长现象,并分别在该两个晶向上表现出纳米晶型和非纳米晶型结构;当用高能离子束辅助沉积时,[102]晶向择尤生长现象消失,且钛膜的结构对束流变化较为敏感,束流较低时,钛膜为纳米结构且择尤生长现象减弱,而束流增加时晶粒长大,择尤生长现象叉增强。另外钛膜容易受到氧的污染,并随辅助离子强度增加而增强。     

MoSx/MoSx-Mo纳米多层膜的制备及其环境摩擦学特性

用直流磁控溅射在钢基体上交替溅射制备了MoSx/MoSx-Mo纳米多层膜。采用划痕仪测试薄膜与基体的结合力;采用SEM和XRD分析了纳米多层膜的形貌和显微结构;在球-盘式微摩擦试验机上测试了纳米多层膜在真空和潮湿空气中的摩擦学性能。结果表明,纳米多层膜的结合力优于纯MoS2膜。随着溅射沉积气压的升高,MoSx(002)面择优取向减弱,纳米多层膜的结合力下降。溅射气压0.24 Pa沉积的纳米多层膜在真空和潮湿空气中都呈现出最低的摩擦因数和磨损率,具有优异的环境摩擦磨损特性。     

Determining concentration depth profiles of thin foam films with neutral impact collision ion scattering spectroscopy

Equipment is developed to measure the concentration depth profiles in foam films with the vacuum based technique neutral impact collision ion scattering spectroscopy. Thin foam films have not previously been investigated using vacuum based techniques, hence specialized methods and equipment have been developed for generating and equilibrating of foam films under vacuum. A specialized film holder has been developed that encloses the foam film in a pressure cell. The pressure cell is air-tight except for apertures that allow for the entrance and exit of the ion beam to facilitate the analysis with the ion scattering technique. The cell is supplied with a reservoir of solvent which evaporates upon evacuating the main chamber. This causes the cell to be maintained at the vapor pressure of the solvent, thus minimizing further evaporation from the films. In order to investigate the effect of varying the pressure over the films, a hydrostatic pressure is applied to the foam films. Concentration depth profiles of the elements in a thin foam film made from a solution of glycerol and the cationic surfactant hexadecyltrimethylammonium bromide (C(16)TAB) were measured. The measured concentration depth profiles are used to compare the charge distribution in foam films with the charge distribution at the surface of a bulk solution. A greater charge separation was observed at the films' surface compared to the bulk surface, which implies a greater electrostatic force contribution to the stabilization of thin foam films.     

16厘米低能强流宽束离子源

介绍了一个新型16厘米束径多会切磁场低能强流宽束离子源(MCLB-16)。由于采用新型多会切磁场和优化的低能引出系统,所以该源在薄膜辅助沉积的能量(200eV～800eV)范围内,具有较好的低能特性。源的最大引出束流可达650mA。可用反应气体或惰性气体工作。源在使用氧气时,可连续工作数十小时。该源可用于各种高性能薄膜制备的辅助沉积,也可用于制备大面积类金钢石膜(DLC)。叙述了该源的结构及性能。     

真空热处理对硫化锌薄膜光学与微结构特性的影响

针对电子束蒸发离子辅助沉积的硫化锌薄膜,研究了550℃以下真空热处理对其光学与微结构特性的影响。薄膜光学和微结构特性的测试分析表明:制备后薄膜为类立方结构的ZnS,在337.5nm波长处出现临界特性转折点,随着热处理温度的增加,转折波长两侧的消光系数变化规律相反,折射率和物理厚度呈现下降趋势,薄膜的禁带宽度逐渐增加;在红外波段的薄膜折射率与热处理温度的变化并不显著,在350℃下热处理时消光系数出现转折,主要是由晶粒变小的趋势所致;通过晶相分析,硫化锌薄膜经历了类立方结构到六方结构的转换,与禁带宽度的变化趋势基本一致。分析结果表明,光学特性变化的根本原因是薄膜的微结构特性变化。     

ECR结合磁控溅射——制备DLC薄膜的新方法

介绍了新型的结合电子回旋共振(ECR)微波等离子体气相沉积与磁控溅射镀膜特点的ECR-650型镀膜系统,并利用该系统通过溅射石墨靶和金属钛靶在不锈钢基底上制备了具有Ti/TiNx/TiNxCy中间层结构的C薄膜。由于镀膜工艺问题,得到的薄膜主要由石墨构成。研究了制备时不同的气压和氩气分压对薄膜表面形貌、硬度等的影响。     

Equipment for deposition of thin metallic films bombarded by fast argon atoms

Deposition of thin metallic films on dielectric substrates using a source of metal atom flow combined with a flow fast argon atoms has been investigated and the investigation results are presented. The fast atoms are produced due to charge-exchange collisions in a vacuum chamber of argon ions, which are accelerated by potential difference between the hollow-cathode glow-discharge plasma and an emissive grid and enter the chamber through the grid. The metal atoms produced due to ion sputtering of a metallic foil placed on the inner surface of the hollow cathode enter the chamber through the same grid. Substrate pretreatment and pulse-periodic bombardment of the growing film by ～1-keV argon atoms both ensure adhesion of copper to glass up to 2 × 10⁷ Pa. The use of a hollow substrate holder, whose inner surface is also covered with the same foil, makes it possible to exclude losses of the depositing metal and allows recommendation of the equipment for beam-assisted deposition of precious metal films.     

A Low-Energy Gas-Discharge Open-End Ion Source without the External Magnetic Field

The described ion source, as oppose to the well-known Hall-type open-end ion source does not require an external magnetic field. The optimal operating parameters of the ion source (discharge voltage is 140 V, discharge current is 2.5 A, and operating pressure is <3.5 × 10^–4Torr) allow one to obtain an argon ion beam with a current of up to 200 mA over an area with a diameter of up to 120 mm and beam current nonuniformity of <25%. This ion source has a long service life under high-temperature operating conditions.