Abstract: In a process for planarization of semiconductor substrates in which a layer which has been applied to a semiconductor substrate which has a trench and/or contact holes is removed such that the layer remains solely in the area of the trenches or contact holes, instead of as in the prior art the etching medium being applied in drops, the etching medium is applied in a continuous flow with a flow rate of at least 0.4 l/min so that the etching medium covers the entire surface of the semiconductor substrate to be planarized. This technique yields a differentiated etching rate, the etching speed in the area of the fields between the trenches or contact holes being greater than in the area of the trenches themselves, so that as a result the coating applied to the semiconductor substrate is etched away more quickly than in the area of the trenches and finally material remains only in the area of the trenches or contact holes.

Abstract: 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.