Needs for processing insulators such as glasses, ceramics, polymers and diamond by plasmas are emerging recently. Problems are arising from electrostatic charging of the insulator surface. In this article, the surface charging of insulator by impact of plasma ions and its effect on processes are briefly reviewed. The pulse bias method and the radio-frequency (RF) bias method are taken as examples of the practical method which is able to circumvent the problem of the surface charging. Finally, the dual plasma method in which no charging happens on the insulator surface even if it is continuously irradiated with energetic ions is proposed.
Shunting arc discharge is a pulsed plasma source of metals and semimetal materials, and is ignited without any trigger sources at a wide range of the gas pressures, from vacuum to atmospheric pressure under identical discharge conditions. In this article, an application of the shunting arc plasma for a preparation of thin film and its process are described. The process using the shunting arc plasma can be divided into two phases; an ignition and an ion extraction phases. The shunting arc plasma is generated by a joule heating with a pulsed large current when the heating energy exceeds a critical value. The generated plasma expanded from the center of source rod with velocity of around 1 km/s. The ions contained in the arc plasma can be extracted by applying a negative pulse to a substrate holder. When the shunting arc is produced in vacuum, only the solid materials are deposited on the substrate. However, in a low-presser gas medium, electrons produced in the shunting arc are accelerated toward the wall, colliding with the gas molecules in the chamber to ionize them. Deposition rate using the shunting arc plasma can be improved with the use of the Lorentz force, which accelerates the entire plasma toward the substrate.
Surface modification using plasma and ion beam processing can significantly change the chemical and physical characteristics of biomaterial surfaces, such as their structure, composition, surface wettability, electrical properties, mechanical properties, electrochemical properties, etc. This kind of surface processing, sometimes in combination with other techniques such as chemical or biochemical methods, can be used to form novel biomaterial surfaces that are anticoagulant, antibacterial, bioactive, biomimetic, wear resistant, and more. In this paper we describe the application of plasma and ion beam processing to the field of biomedical materials.
Recent trend in simulation studies will be reviewed briefly in the field of plasma ion processes. In plasma ion processes, materials to be processed are immersed in a plasma. Since the sheath potential structure around the material surface is one of the key parameters governing the ion processes, emphasis will be put on the dynamics of transient ion sheath after a negative voltage is applied to the materials to be processed. After describing the concept of ion sheath, a one-dimensional model for ion sheath evolution is discussed. Both analytic and numerical models will then be introduced for more complicated realistic situations. Finally, a simulation model for plasma source, which will become one of the most important topics in control of plasma parameters for ion processes, will be discussed.
We introduce a simple evaporator for metal evaporation mounted on a conflat flange with an outer diameter of 70 mm. It consists of a tantalum filament, an aluminum tube with a pinhole, and a four-pin feedthrough mounted on a conflat flange with an outer diameter of 70 mm.
In year 2007, Nobel prize for Chemistry was awarded to Prof. Gerhard Ertl, former director of Fritz Haber Institute, Berlin. The article is to introduce the brilliant achievement of Prof. Ertl in part.