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US 7,404,874 B2Granted
Method and apparatus for treating wafer edge region with toroidal plasma
AssigneeInternational Business Machines Corporation
InventorsWilliam George America, Steven Hilton Johnston
Life of this patent
Estimating the term…
Abstract
Method and apparatus for treating an edge region of a wafer. A toroidal shaped plasma cavity has an inner diameter which is slightly less than the diameter of the wafer being treated so that only the edge region of the wafer extends into the toroidal plasma cavity. An inert gas is flowed across a front and back side of the wafer into the plasma cavity. A reactive gas is flowed directly into the plasma cavity. The gases exit the plasma cavity without flowing over the surface of the wafer.
Claims12
A method of treating a peripheral edge region of a wafer comprising the steps of:
- providing a plasma chamber having a U-shaped upper portion and an opposing U-shaped lower portion, and including a toroidal shaped plasma cavity therebetween;
- providing two electrodes in the plasma cavity, an upper electrode disposed at an upper portion of the plasma cavity and a lower electrode disposed at a lower portion of the plasma cavity;
- providing an inner annular gap extending from an external surface of the plasma chamber into the plasma cavity between the upper and lower electrodes;
- providing an outer gap leading from the plasma cavity to the outer surface of the plasma chamber between the upper and lower electrodes;
- disposing only the peripheral edge region of the wafer through the annular inner gap and within the plasma cavity;
- flowing a reactive gas directly into the plasma cavity;
- forming a plasma within the plasma cavity;
- exiting the reactive gas from the plasma cavity through the outer gap;
- and
- flowing an inert gas across a front and back side of the wafer and through the inner annular gap and across the peripheral edge of the wafer disposed within the plasma cavity and out through the outer gap whereby the reactive gas exits the plasma cavity without flowing over the back or front side of the wafer.
7 more elements
An apparatus for treating an edge region of a wafer comprising:
- a plasma chamber having a U-shaped upper portion and an opposing U-shaped lower portion, and including a toroidal shaped plasma cavity therebetween and the toroidal shaped plasma cavity having an inner diameter which is slightly less than an overall diameter of a wafer being treated so that only an edge region of the wafer extends into the plasma cavity;
- means for receiving an edge region of the wafer within the plasma cavity, the means including an annular gap extending from an inner surface of the plasma chamber into the plasma cavity for allowing the edge region of the wafer to extend into the plasma cavity;
- means for forming a plasma within the plasma cavity, the means for forming the plasma comprises an upper electrode disposed in an upper portion of the plasma cavity and a lower electrode disposed in a lower portion of the plasma cavity and holes in at least one of the upper and lower electrodes for flowing a reactive gas directly into the plasma cavity;
- and
- means for flowing an inert gas across a front and back side of the wafer and through the annular gap disposed between the upper and lower portions of the plasma chamber into the plasma cavity whereby the reactive gas exits the plasma cavity without flowing over the back or front side of the wafer.
2 more elements
An apparatus for treating a peripheral edge region of a wafer comprising:
- means for providing a plasma chamber having a U-shaped upper portion and an opposing U-shaped lower portion, and including a toroidal shaped plasma cavity therebetween;
- means for providing two electrodes in the plasma cavity, an upper electrode disposed at an upper portion of the plasma cavity and a lower electrode disposed at a lower portion of the plasma cavity;
- means for providing an inner annular gap extending from an external surface of the plasma chamber into the plasma cavity between the upper and lower electrodes;
- means for providing an outer gap leading from the plasma cavity to the outer surface of the plasma chamber between the upper and lower electrodes;
- means for disposing only the peripheral edge region of the wafer through the annular inner gap and within the plasma cavity;
- means for flowing a reactive gas directly into the plasma cavity;
- means for forming a plasma within the plasma cavity;
- means for exiting the reactive gas from the plasma cavity through the outer gap;
- and
- means for flowing an inert gas across a front and back side of the wafer and through the inner annular gap and across the peripheral edge disposed within the plasma cavity and out through the outer gap whereby the reactive gas exits the plasma cavity without flowing over the back or front side of the wafer.
7 more elements
Dependencies are inferred from the claim text.