Uniform gas cushion wafer support
AssigneeAxcelis Technologies, Inc.
InventorsAri Eiriksson, Richard Gueler, Michel Pharand
Life of this patent
Estimating the term…
Abstract
A workpiece is supported on a gas cushion to reduce mechanical stresses on the workpiece during processing. A plenum having a workpiece support flange for receiving the workpiece is connected to a gas supply. When gas flows into the plenum and pressure increases sufficiently to lift the workpiece, the workpiece is lifted and the gas flows out of the plenum between the flange and the workpiece edge. The workpiece is thus supported above the flange by the gas during processing.
Claims9
An apparatus for supporting a thin, planar workpiece comprising;
- a plenum in fluid communication with a gas supply and comprising a workpiece support flange having an inner diameter slightly smaller than an outer diameter of the workpiece;
- an edge ring that movably rests on the support flange and contacts an outer edge of the workpiece and wherein the edge ring has an inner diameter slightly smaller than the outer diameter of the workpiece and an outer diameter slightly larger than an outer diameter of the workpiece and wherein when the workpiece is placed on the support flange an outer edge of the workpiece rests upon the edge ring;
- and
- wherein when a workpiece is placed on the support flange and gas is supplied to the plenum the edge ring is lifted by the gas in contact with the outer edge of the workpiece such that the inner diameter of the support flange coacts with an outer diameter of the edge ring to define a gas flow path through which the supplied gas flows when the edge ring and the workpiece is are lifted off the support flange.
An apparatus for supporting a thin, planar workpiece comprising;
- a plenum in fluid communication with a gas supply and comprising a workpiece support flange having an inner diameter slightly smaller than an outer diameter of the workpiece;
- locating structure disposed about a periphery of the support flange that maintains the workpiece location with respect to the support flange;
- a wafer edge ring that movably rests on the workpiece support flange and is maintained in position by the locating structure, the edge ring comprising an inner diameter slightly smaller than the outer diameter of the workpiece and an outer diameter slightly larger than the outer diameter of the workpiece;
- and
- wherein when a workpiece is placed on the edge ring and gas is supplied to the plenum the edge ring is lifted by the gas in contact with the outer edge of the workpiece such that the inner diameter of the support flange coacts with an outer diameter of the edge ring to define a gas flow path through which the supplied gas flows when the edge ring and the workpiece are lifted off the support flange.
Dependencies are inferred from the claim text.