Patent ID: 6162739
Filing Date: 2000-12-19
Classification: H01L

Abstract:
Process for wet etching of a semiconductor wafer to entirely remove from a first side of the semiconductor wafer a silicon dioxide layer, and to selectively remove from a first edge area of a second side of the semiconductor wafer the silicon dioxide layer, said process comprising the steps of:preparing a liquid etching medium which contains a component which is effective relative in removing the silicon dioxide layer; androtating the semiconductor wafer and applying to the rotating semiconductor wafer the liquid etching medium to entirely etch the silicon dioxide layer from the first side and to selectively etch of the silicon dioxide layer located the second side only in the first edge area of the second side,wherein the etching medium comprises hydrofluoric acid and at least one carboxylic acid, andwherein the etching medium is allowed to flow around from the first side over an edge of the semiconductor wafer and onto the first edge area of the second side of the semiconductor wafer to selectively etch the silicon dioxide from the first edge area.