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Deposition of Diamond-Like Carbon Films using Plasma Based Ion Implantation with Bipolar Pulses S.Miyagawa and Y.Miyagawa Particle Beam Science Laboratory, National Industrial Research Institute of Nagoya 1-1 Hirate-cho, Kita-ku, Nagoya 462-8510, Japan ABSTRACT Plasma based ion implantation (PBII) with bipolar high voltage pulses has been proposed to improve a dose uniformity in an ion implantation on a three-dimensional target. A pulsed glow discharge plasma is produced around the target by a positive high-voltage pulse, and then ions are implanted into the target from all sides by the subsequent negative high-voltage pulse. A time resolved plasma density and the spatial profiles of the pulsed glow discharge plasma are measured by a Langmuir probe in a boxcar mode, and diamond like carbon (DLC) films are deposited under optimal conditions of the pulsed plasma. It is shown that the PBII with bipolar pulses is a useful method in depositing DLC films on the three-dimensional target. A carbon ion implantation procedure results in the enhanced adherence of DLC coating to the target, and the enhanced adhesion is due to a graded carbon interface produced by carbon implantation. INTRODUCTION PBII is a rapidly developing technique for surface modification of three-dimensional workpieces. In the PBII process, negative high voltage pulses of 1~100 kV are applied to a target immersed in a plasma. Plasma ions produced by a plasma source, e.g., RF, ECR, Arc, etc., are accelerated and implanted into the target from all sides simultaneously through a high voltage ion sheath. However the uniformity of ion implantation dose and the film thickness deposited on the three-dimensional target are insufficient, because the ion current impinging on the target depends not only the distance from the plasma source, but also the direction of the target surface to the plasma source [1]. Diamond-like carbon (DLC) coatings are of technological interest for enhancing wear resistance and corrosion resistance of metals, and it has been expected to be applied for a coating of large areas with more complex surface geometry. However an improvement of the adhesion to the substrate is an important subject because of high internal compressive stress of DLC films. One of the promising techniques to improve the adhesion is PBII processing to create a carbon composition gradient in the surface [2,3]. In this work, PBII processing with bipolar high voltage pulses applied directly on the target has been proposed to improve the uniformity of an implantation and the deposition on the three-dimensional target. The ions of glow discharge plasma by a positive pulse on the target are implanted into the target omnidirectionally with a subsequent negative high voltage pulse. The time resolved plasma density and the spatial profiles of the pulsed plasma are measured, and DLC thin films are synthesized. EXPERIMENTAL DETAILS Figure 1 shows a schematic of the PBII system using bipolar high voltage pulses. The system is mainly composed of a target holder insulated from the