Method for the treatment of a web-type material in a plasma-assisted process

A device for treating a web material in a plasma enhanced process, the device comprising a vacuum chamber (1) with means (2) for maintaining a constant reduced pressure within the chamber (1) and, arranged within the chamber (1), a web supporting and transporting means, a magnetron means facing the web (4) supported and transported by the supporting and transporting means and a gas supply means for supplying a process gas or process gas mixture to a space (10) between the supporting and transporting means and the magnetron means, wherein the magnetron means comprises a plurality of independent magnetron electrodes (6) with rectangular magnetron faces, each magnetron electrode (6) being powered with an alternating voltage by its own power supply means (7), and the magnetron faces being arranged beside each other in parallel and at a distance from the supporting and transporting means, and wherein the supporting and transporting means is one of electrically grounded, electrically floating and negatively biased.