Plasma generation for thin film deposition on flexible substrates

A system for depositing a thin film on a flexible substrate, comprising:

• a first zone supplied with a first precursor gas when the system is in use;
• a second zone supplied with a second precursor gas when the system is in use;
• a third zone supplied with a third precursor gas when the system is in use, the third zone including a series of flow-restricting passageways opening into the first zone and second zone and arranged to provide a pathway along which a flexible substrate is threaded so that, when the system is in use, the flexible substrate is exposed to the first precursor gas in the first zone, the second precursor gas in the second zone, and the third precursor gas in the third zone;
• a plasma generator positioned in a gap formed between adjacent flow restricting passageways along the pathway within the third zone to generate radicals of the third precursor gas that are reactive with an amount of the first precursor gas, the second precursor gas, or combinations thereof, previously adsorbed to the flexible substrate upon exposure to the first precursor zone and second precursor zone, respectively, the plasma generator including two electrodes that are electrically isolated from one another and that extend toward one another in planes paralleling a portion of the pathway in the third zone, a first of the two electrodes including a pair of electrically connected conductors spaced apart from one another and positioned on either side of a conductor included in a second of the two electrodes so that one of the conductors in the first electrode is positioned between the pathway and the conductor included in the second electrode;
• a power supply electrically connected with the plasma generator;
• and
• a substrate transport mechanism adapted to guide the flexible substrate back and forth via a plurality of turning guides, at least some of which are located in the first and second zones, between the first and second zones along the pathway and through series of flow-restricting passageways so that a surface of the flexible substrate is transported past the plasma region and exposed to the radicals when the system is in use.

A method of exposing a flexible substrate to a plasma region, the method comprising:

• introducing a first precursor gas into a first zone;
• introducing a second precursor gas into a second zone;
• introducing a third precursor gas into a third zone a third zone, the third zone including a series of flow-restricting passageways opening into the first zone and second zone and arranged to provide a pathway along which a flexible substrate is threaded such that the flexible substrate is exposed to the first precursor gas in the first zone, the second precursor gas in the second zone, and the third precursor in the third zone;
• generating radicals of the third precursor gas in a plasma region proximal to the pathway in the third region with a plasma generator positioned in a gap formed between adjacent flow restricting passageways along the pathway within the third zone, the plasma generator including a channel-shaped electrode formed from a pair of flanges joined by a web portion and a cantilevered electrode that extends toward the web portion so that a space formed between the flanges is interposed between the web portion and the cantilevered electrode, wherein the channel-shaped electrode and the cantilevered electrode extend toward one another in planes paralleling adjacent portions of the pathway along which the flexible substrate is threaded;
• and
• guiding the flexible substrate back and forth via a plurality of turning guides, at least some of which are located in the first and second zones, between the first and second zones along the pathway and through the series of flow-restricting passageways so that a surface of the flexible substrate is transported past the plasma region and exposed to the radicals.