Method for removing substrate layers

• Main Authors: DELAHAYE, FRANCK, QUEISSER, STEFFEN, SANDER, BERND-UWE
• Format: Patent
• Language: Chinese; English
• Published: 01.07.2011
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; SEMICONDUCTOR DEVICES

The present invention relates to a method for the exclusively one-sided wet chemical removal of passivating and/or dielectric oxide layers present on flat substrates, such as in particular silicon wafers, by means of one-sided etching of the underside of a substrate transported horizontally through a tank filled with an etching liquid. When said method is used, there is no need for any protection in the form of a coating or mechanical aid for the face of the substrate that is not to be treated. According to the invention, the etching liquid contains water, hydrofluoric acid and at least one further component selected from the group consisting of sulphuric and phosphoric acid and the alkali, ammonium and organoammonium acid salts and salts thereof, hexafluorosilicic acid, and silicon tetrafluoride.