Plasma uniformity control by gas diffuser hole design
First Claim
1. A gas distribution plate assembly for a plasma processing chamber, comprising:
- a diffuser plate element having an edge, a center, an upstream side and a concave downstream side; and
inner and outer gas passages passing between the upstream and downstream sides of the diffuser plate element from the center to the edge of the diffuser plate element, each gas passage having;
an orifice hole having a first diameter; and
a hollow cathode cavity that is downstream of the orifice hole and is at the downstream side, the hollow cathode cavity having a cone or cylinder shape and a second diameter at the downstream side that is greater than the first diameter, the second diameters or the depths or a combination of both of the cones or cylinders increases from the center to the edge of the diffuser plate element, the first diameters are substantially uniform from the center to the edge of the diffuser plate element, and the size of the hollow cathode cavities of the inner gas passages is less than the size of the hollow cathode cavities of the outer gas passages.
1 Assignment
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Accused Products
Abstract
Embodiments of a gas diffuser plate for distributing gas in a processing chamber are provided. The gas distribution plate includes a diffuser plate having an upstream side and a downstream side, and a plurality of gas passages passing between the upstream and downstream sides of the diffuser plate. The gas passages include hollow cathode cavities at the downstream side to enhance plasma ionization. The depths, the diameters, the surface area and density of hollow cathode cavities of the gas passages that extend to the downstream end can be gradually increased from the center to the edge of the diffuser plate to improve the film thickness and property uniformity across the substrate. The increasing diameters, depths and surface areas from the center to the edge of the diffuser plate can be created by bending the diffuser plate toward downstream side, followed by machining out the convex downstream side. Bending the diffuser plate can be accomplished by a thermal process or a vacuum process. The increasing diameters, depths and surface areas from the center to the edge of the diffuser plate can also be created computer numerically controlled machining. Diffuser plates with gradually increasing diameters, depths and surface areas of the hollow cathode cavities from the center to the edge of the diffuser plate have been shown to produce improved uniformities of film thickness and film properties.
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Citations
95 Claims
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1. A gas distribution plate assembly for a plasma processing chamber, comprising:
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a diffuser plate element having an edge, a center, an upstream side and a concave downstream side; and inner and outer gas passages passing between the upstream and downstream sides of the diffuser plate element from the center to the edge of the diffuser plate element, each gas passage having; an orifice hole having a first diameter; and a hollow cathode cavity that is downstream of the orifice hole and is at the downstream side, the hollow cathode cavity having a cone or cylinder shape and a second diameter at the downstream side that is greater than the first diameter, the second diameters or the depths or a combination of both of the cones or cylinders increases from the center to the edge of the diffuser plate element, the first diameters are substantially uniform from the center to the edge of the diffuser plate element, and the size of the hollow cathode cavities of the inner gas passages is less than the size of the hollow cathode cavities of the outer gas passages. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. A gas distribution plate assembly for a plasma processing chamber, comprising:
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a diffuser plate element having an edge, a center, an upstream side and a downstream side; and inner and outer gas passages passing between the upstream and downstream sides of the diffuser plate element from the center to the edge of the diffuser plate element, each gas passage having; an orifice hole having a first diameter; and a hollow cathode cavity that is downstream of the orifice hole and is at the downstream side, the hollow cathode cavity having a cone or cylinder shape and a second diameter at the downstream side that is greater than the first diameter, the second diameters or the depths or a combination of both of the cones or cylinders increases from the center to the edge of the diffuser plate element, the first diameters are substantially uniform from the center to the edge of the diffuser plate element, and the hollow cathode cavity surface area density of the inner gas passages is less than the hollow cathode cavity surface area density of the outer gas passages. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31)
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32. A gas distribution plate assembly for a plasma processing chamber, comprising:
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a diffuser plate element having an edge, a center, an upstream side and a downstream side; and a plurality of gas passages passing between the upstream and downstream sides of the diffuser plate element from the center to the edge of the diffuser plate element, each gas passage having; an orifice hole having a first diameter; and a hollow cathode cavity that is downstream of the orifice hole and intersects the downstream side of the diffuser plate element, the hollow cathode cavity having a cone or cylinder shape and a second diameter at the downstream side that is greater than the first diameter, the second diameters or the depths or a combination of both of the cones or cylinders increases from the center to the edge of the diffuser plate element, the first diameters are substantially uniform from the center to the edge of the diffuser plate element, the densities of the hollow cathode cavities increase from the center to the edge of the diffuser plate element, and the hollow cathode cavity volume density or the hollow cathode cavity surface area density increases from the center to the edge of the diffuser plate element. - View Dependent Claims (33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44)
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45. A plasma processing chamber, comprising:
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a diffuser plate element having an edge, a center, an upstream side and a downstream side; a RF power source coupled to the diffuser plate element; inner and outer gas passages passing between the upstream and downstream sides of the diffuser plate element from the center to the edge of the diffuser plate element, each gas passage having; an orifice hole having a first diameter; and a hollow cathode cavity that is downstream of the orifice hole and is at the downstream side, the hollow cathode cavity having a cone or cylinder shape and a second diameter at the downstream side that is greater than the first diameter, the second diameters or the depths or a combination of both of the cones or cylinders increases from the center to the edge of the diffuser plate element, the first diameters are substantially uniform from the center to the edge of the diffuser plate element, and the size of the hollow cathode cavities of the inner gas passages is less than the size of the hollow cathode cavities of the outer gas passages; and a substrate support adjacent the downstream side of the diffuser plate element. - View Dependent Claims (46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56)
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57. A plasma processing chamber, comprising:
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a diffuser plate element having an edge, a center, an upstream side and a downstream side; a RF power source coupled to the diffuser plate element; inner and outer gas passages passing between the upstream and downstream sides of the diffuser plate element from the center to the edge of the diffuser plate element, each gas passage having; an orifice hole having a first diameter; and a hollow cathode cavity that is downstream of the orifice hole and is at the downstream side, the hollow cathode cavity having a cone or cylinder shape and a second diameter at the downstream side that is greater than the first diameter, the second diameters or the depths or a combination of both of the cones or cylinders increases from the center to the edge of the diffuser plate element, the first diameters are substantially uniform from the center to the edge of the diffuser plate element, and the hollow cathode cavity surface area density of the inner gas passages is less than the hollow cathode cavity surface area density of the outer gas passages; and a substrate support adjacent the downstream side of the diffuser plate element. - View Dependent Claims (58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68)
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69. A plasma processing chamber, comprising:
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a diffuser plate element having an edge, a center, an upstream side and a downstream side; a RF power source coupled to the diffuser plate element; a plurality of gas passages passing between the upstream and downstream sides of the diffuser plate element from the center to the edge of the diffuser plate element, each gas passage having; an orifice hole having a first diameter; and a hollow cathode cavity that is downstream of the orifice hole and is at the downstream side, the hollow cathode cavity having a cone or cylinder shape and a second diameter at the downstream side that is greater than the first diameter, the second diameters or the depths or a combination of both of the cones or cylinders increases from the center to the edge of the diffuser plate element, the first diameters are substantially uniform from the center to the edge of the diffuser plate element, and surface area densities of hollow cathode cavities of the plurality of gas passages increase from the center to the edge of the diffuser plate element; and a substrate support adjacent the downstream side of the diffuser plate element. - View Dependent Claims (70, 71, 72, 73, 74, 75, 76, 77, 78, 79)
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80. A gas distribution plate assembly for a plasma processing chamber, comprising:
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a diffuser plate element having an edge, a center, an upstream side and a downstream side and the diffuser plate is divided into a number of concentric zones; and a plurality of gas passages passing between the upstream and downstream sides of the diffuser plate element from the center to the edge of the diffuser plate element, each gas passage having; an orifice hole having a first diameter; and a hollow cathode cavity that is downstream of the orifice hole and is at the downstream side, the hollow cathode cavity having a cone or cylinder shape and a second diameter at the downstream side that is greater than the first diameter, the second diameters or the depths or a combination of both of the cones or cylinders increases from the center to the edge of the diffuser plate element, the first diameters are substantially uniform from the center to the edge of the diffuser plate element, the gas passages in each zone are identical and the volume or surface area of hollow cathode cavities of gas passages in each zone gradually increase from the center to the edge of the diffuser plate element. - View Dependent Claims (81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91)
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92. A diffuser plate, comprising:
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a body having an edge, a center, a top surface and a bottom surface, wherein the bottom surface is concave; a plurality of gas passages between the top surface and the bottom surface, from the center to the edge of the body wherein each gas passage has; an orifice hole having a first diameter; and a hollow cathode cavity that is downstream of the orifice hole and intersects the bottom surface, the hollow cathode cavity having a cone or cylinder shape and a second diameter at the downstream side that is greater than the first diameter, the second diameters or the depths or a combination of both of the cones or cylinders increases from the center to the edge of the diffuser plate, the first diameters are substantially uniform from the center to the edge of the diffuser plate, and the size of the hollow cathode cavities increases from the center to the edge of the diffuser plate; and an outer region and an inner region wherein the body between the top and the bottom of the outer region is thicker than the body between the top and the bottom of the inner region. - View Dependent Claims (93, 94, 95)
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Specification