Abstract: A method of modifying a substrate using a plasma comprises providing a first electrode and a second electrode; arranging the substrate such that only a portion of the substrate is between the electrodes; and rotating either the substrate or at least one of the electrodes about an axis so as to cause different portions of the substrate to pass between the electrodes during the rotation. A voltage is supplied to at least one of the electrodes so as to create a plasma discharge between the electrodes which contacts at least the portions of the substrate that pass between the electrodes. The electrodes and the substrate are arranged such that the rotating causes the speed of transit of the substrate portion between the electrodes to vary in a radial direction away from the axis of rotation and the rate that the plasma discharge modifies the substrate varies across the substrate.

Abstract: A method of modifying a substrate using a plasma comprises providing a first electrode and a second electrode; arranging the substrate such that only a portion of the substrate is between the electrodes; and rotating either the substrate or at least one of the electrodes about an axis so as to cause different portions of the substrate to pass between the electrodes during the rotation. A voltage is supplied to at least one of the electrodes so as to create a plasma discharge between the electrodes which contacts at least the portions of the substrate that pass between the electrodes. The electrodes and the substrate are arranged such that the rotating causes the speed of transit of the substrate portion between the electrodes to vary in a radial direction away from the axis of rotation and the rate that the plasma discharge modifies the substrate varies across the substrate.