Atomic layer deposition apparatus
View Patent ↗The present invention relates to an ALD apparatus, and particularly relates to an ALD apparatus that is suitable for rapidly depositing a thin film on a substrate having an actual area that is larger than a planar substrate. In the reaction chamber of the ALD apparatus according to an exemplary embodiment of the present invention, more gas is supplied to a portion where more gas is required by having differences in the space for gas to flow rather than supplying the gas in a constant flux and a constant flow velocity such that the time required for supplying reactant gases and waste of reactant gases may be minimized to increase productivity of the ALD apparatus. The ceiling of the reaction space is shaped to provide a nonuniform gap over the substrate.
1. A method of conducting atomic layer deposition (ALD), comprising:
providing a substrate in a reaction chamber; and
alternately and sequentially supplying at least two ALD reactants into the reaction chamber space over the substrate in a gas flow direction parallel to the substrate, wherein the reaction space has a concave ceiling with a tubular shape such that the reaction space has a height over a center of the substrate greater than a height over edges of the substrate in a cross-sectional view perpendicular to the gas flow direction, and such that the reaction space has substantially the same height along the gas flow direction,
wherein the height over the center and the height over the edges are such that a maximum gas flow over the substrate is over the center, and a minimum gas flow rate over the substrate is over the edges, and
wherein gas flow rates decrease in the direction perpendicular to the gas flow direction from the maximum flow rate over the center to the minimum flow rate over the edges.
2. The method of claim 1 , wherein providing the substrate comprises providing a partially fabricated substrate with a surface area at least 10 times a surface of a similarly sized planar substrate.
3. The method of claim 1 , wherein providing the substrate comprises providing a partially fabricated substrate with a surface area at least 50 times a surface of a similarly sized planar substrate.
4. The method of claim 1 , wherein the reaction space has a maximum height over the substrate and a minimum height above the substrate, wherein the maximum height is at least 1.5 times the minimum height.
5. The method of claim 1 , wherein the reaction space has a maximum height over the substrate and a minimum height above the substrate, wherein the maximum height is at least 2 times the minimum height.
6. The method of claim 1 , wherein a gap between one of the edges of the substrate and the concave ceiling is between about 0.5 mm and about 5 mm.
7. The method of claim 6 , wherein the gap between the one of the edges of the substrate and the concave ceiling is between about 1 mm and about 3 mm.
8. The method of claim 1 , wherein a gap between the center of the substrate and the concave ceiling is between about 2 mm and about 15 mm.
9. The method of claim 8 , wherein the gap between the center of the substrate and the concave ceiling is between about 3 mm and about 6 mm.