Characteristics of an ion beam modification system with a linear ion source

Abstract

Characteristics of an ion beam surface modification system with a linear ion source are described in this article. The linear ion source is principally based on an anode layer thruster, which is generally referred to as “closed drift thruster.” The linear ion source has a slit type racetrack-shape extraction geometry. The spatial current distribution of the extracted ion beam has, therefore, a racetrack shape. Experiments were carried out for the discharge voltages ranging from 500 to 1500 V and ion doses ranging from 7.3×1013 to 8.2×1014 ions/cm2, using three kinds of ion species, namely, oxygen, nitrogen, and argon. Ion beam current density was uniform in the direction of the straight part of the extraction slit. Metalization of the surface modified polymers was also performed. To study the improvement of the adhesion of the metal films to the polymers, the peel-off tests were carried out on ion-irradiated polyimide-copper films. The results indicated that adhesion strength between polyimide and copper was improved as a result of the surface modification by the linear ion source.