Apparatus and method for dielectric deposition
The disclosed invention includes apparatus and methods that may be used for plasma-based deposition of thin layers of material on separate or continuous web substrates at very low temperatures with very low defect density. It achieves superior control of gas phase chemistry by controlling the sequence of introduction of gaseous components. It also has substantially independent control over the rate of chemical processes in the gas and of the amount of power and energy of ion bombardment. Such control enables high quality single and multi-layer films to be deposited cost effectively and uniformly over larger areas under very low temperature conditions.
1. A method for chemical vapor deposition of coatings of materials on a substrate at a temperature less than 150° C. within an evacuated chamber containing two or more elongated electrodes, the method comprising:
moving the substrate (i) perpendicular to a long dimension of a first electrode of said two or more elongated electrodes, (ii) parallel to a short dimension of the first electrode, and (iii) between said first electrode and a support structure in the evacuated chamber, wherein: (i) a minimum gap between a bottom surface of the first electrode and the substrate is less than a width of the first electrode, the width of the first electrode measured along the short dimension, (ii) the first electrode has one or more grooves running the long dimension of the first electrode and divides the first electrode into two or more main sections where each of said one or more grooves is between 5 millimeters and 4 centimeters wide, and (iii) the first electrode is connected to one or more alternating current (AC) power sources;
powering the first electrode with said one or more AC power sources;
injecting a first reactant gas into a first groove of said one or more grooves in said first electrode into a first region within the first groove furthest away from the substrate, so that the first reactant gas flows toward the substrate; and
injecting a second gas including a gas-phase precursor compound containing at least one of silicon, metal, and carbon into a second region within the first groove, downstream of the first reactant gas flow from said first region, so that the second gas mixes with the first reactant gas to form a mixed gas with a gas pressure, and after flowing between the first electrode and the substrate, the mixed gas flows away from the substrate past a side defining the long dimension of said first electrode and is exhausted from the chamber.
2. The method of claim 1 , wherein said minimum gap between the bottom surface of the first electrode and the substrate is between 10 mm and 40 mm.
3. The method of claim 1 , wherein (i) the first reactant gas includes at least one compound containing one of the elements oxygen and nitrogen, (ii) the second gas includes a silicon-containing vapor, and (iii) a dielectric layer containing silicon is deposited on the substrate which is maintained at a temperature below 100° C.
4. The method of claim 1 , wherein (i) the first reactant gas includes at least one compound containing oxygen or nitrogen, (ii) the second gas includes a vapor containing at least one metal, and (iii) a film containing at least one metal is deposited on the substrate.
5. The method of claim 1 , wherein the gas pressure is below 3 Torr, and the total flow of injected gas per meter of electrode length is between about 425 standard cubic centimeters per minute (SCCM) and 3600 SCCM.