Wafer support system
First Claim
1. In a plasma etching apparatus comprising a vacuum chamber, a first electrode received within said vacuum chamber, a second electrode received within said vacuum chamber in spaced relation to said first electrode, a wafer-receiving surface formed on said second electrode, a first supply of a first gas, and means for conducting said first gas from said first supply into said vacuum chamber;
- the improvement comprising a plurality of orifices formed in said wafer-receiving surface, a second supply of a second gas, and means conducting said second gas from said second supply to said orifices to define gas bearing means supporting said wafers above said second electrode.
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Accused Products
Abstract
A system for supporting wafers (18) on a gas cushion within the vacuum chamber (12) of a plasma etcher (10). An etchant gas is introduced into the vacuum chamber, and a second gas at a volume flow rate much lower than the volume flow rate of the etchant gas is directed to orifices formed in a wafer-receiving surface of an electrode (16) to define the gas cushion. In accordance with one aspect of the invention, the second gas is an inert gas, and in accordance with another aspect of the invention, the second gas is a reactant gas which is also directed into the vacuum chamber to serve as a reactant gas in conjunction with the first reactant gas.
37 Citations
13 Claims
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1. In a plasma etching apparatus comprising a vacuum chamber, a first electrode received within said vacuum chamber, a second electrode received within said vacuum chamber in spaced relation to said first electrode, a wafer-receiving surface formed on said second electrode, a first supply of a first gas, and means for conducting said first gas from said first supply into said vacuum chamber;
- the improvement comprising a plurality of orifices formed in said wafer-receiving surface, a second supply of a second gas, and means conducting said second gas from said second supply to said orifices to define gas bearing means supporting said wafers above said second electrode.
- View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
- 9. A method of operating a plasma etcher comprising positioning one or more wafers on an electrode within the vacuum chamber of said plasma etcher, directing a flow of a first gas into said vacuum chamber above said one or more wafers at a first predetermined volume flow, and selectively directing a second gas into said vacuum chamber through said electrode toward the one or more wafers positioned thereon at a second predetermined volume flow to alternately support said one or more wafers on a cushion of said second gas and then allow said one or more wafers to come to rest in engagement with said electrode.
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13. A method of operating a plasma etcher comprising moving wafers one by one into an entrance end of the vacuum chamber thereof and onto a surface of an electrode of said plasma etcher, said surface being inclined slightly downward from the horizontal toward the exit end of the chamber;
- directing a flow of a first gas into said vacuum chamber above said electrode at a first predetermined volume flow; and
selectively directing a second gas into said vacuum chamber through said electrode and toward the wafers thereon to alternately support said wafers on a cushion of said second gas and then to allow said one or more wafers to come to rest in engagement with said electrode, said wafers being moved by gravity toward said exit end when said wafers are supported by the second gas.
- directing a flow of a first gas into said vacuum chamber above said electrode at a first predetermined volume flow; and
Specification