Device and process for liquid treatment of wafer-shaped articles
A device for liquid treatment of a defined area of a wafer-shaped article, especially of a wafer, near the edge, in which the liquid is applied to a first surface, flows essentially radially to the outside to the peripheral-side edge of the wafer-shaped article and around this edge onto the second surface, the liquid wetting a defined section near the edge on the second surface and thereupon being removed from the wafer-shaped article.
1. A device for wet etching with a liquid a defined area of a first surface of a wafer-shaped article, the defined area being adjacent to a peripheral edge of the wafer-shaped article, the device comprising:
holding means for holding the wafer-shaped article with the first surface facing, within the defined area, a surface of said holding means that is parallel to the first surface, said holding means comprising gas feed means for at least partial flushing of a gas from the first surface, and a gas guide in a periphery of said holding means; and
said gas guide being arranged to be separated from the first surface by a gap and having a channel to divert most of the gas away from the defined area when the wafer-shaped article is being held by said holding means, said gap having a width that permits creation of a capillary force that causes the liquid to enter into said gap and to wet and etch the defined area of the first surface adjacent to the peripheral edge, wherein within the defined area, a surface of said gas guide facing the first surface is parallel to the first surface.
2. The device of claim 1 , wherein said gas guide is ring-shaped.
3. The device of claim 2 , wherein said ring-shaped gas guide has an inner diameter that is smaller than an outside diameter of the wafer-shaped article and an outside diameter that is at least a same size as the outside diameter of the wafer-shaped article.
4. The device of claim 1 , wherein said gas guide is formed by an annular groove that is concentric to said periphery of said holding means and from which a gas is discharged.
5. The device of claim 1 , wherein a part of said holding means is located between said gas feed means and said gas guide, and said part is located at a greater distance from the wafer-shaped article than said gas guide is from the wafer-shaped article.
6. The device of claim 1 , wherein said gap is 0.05 to 1 mm.
7. The device of claim 1 , wherein said gas guide is annular and surrounds said holding means and said gas feed means.
8. The device of claim 1 , wherein said gas guide comprises a radially inward projection that diverts the gas away from the defined area.
9. A device for treating with a liquid a wafer-shaped article having a first surface, a second surface opposite the first surface, and a peripheral edge between the first and second surfaces, the device comprising:
holding means for holding the wafer-shaped article with the second surface facing said holding means, said holding means comprising gas feed means for at least partial flushing of a gas from the second surface, and a gas guide in a periphery of said holding means;
said gas guide being arranged to be separated from the second surface by a gap when the wafer-shaped article is being held by said holding means, said gap having a width that permits creation of a capillary force that causes the liquid to enter into said gap and to wet and treat a defined area of the second surface adjacent to the peripheral edge, wherein within the defined area, a surface of said gas guide facing the second surface is parallel to the second surface; and
a channel that branches from a radially inward end of said gap.
10. A device for treating with a liquid a wafer-shaped article having a first surface, a second surface opposite the first surface, and a peripheral edge between the first and second surfaces, the device comprising:
holding means for holding the wafer-shaped article with the second surface facing said holding means, said holding means comprising gas feed means for at least partial flushing of a gas from the second surface, and a gas guide in a periphery of said holding means;
said gas guide being arranged to be separated from the second surface by a gap when the wafer-shaped article is being held by said holding means, said gap having a width that permits creation of a capillary force that causes the liquid to enter into said gap and to wet and treat a defined area of the second surface adjacent to the peripheral edge, wherein within the defined area, a surface of said gas guide facing the second surface is parallel to the second surface; and
said gap extending radially inward from the peripheral edge to a recess in the holder, the radially inward extent of the gap defining the defined area.