Method for etching a semiconductor element, its use for etching end point detection and a device for carrying it out

Abstract

A method is provided for detecting an end point, a material transition or a boundary surface during the etching of a semiconductor element, a zone of the semiconductor element having non-homogeneous load carrier density and/or non-homogeneous load carrier polarity, particularly a p-n junction, which has an electrical voltage applied to it during etching, and an electrical current induced by it in this zone is measured, and reaching of this zone during etching is determined from a change in the electrical current. This method is suitable for the detection of the etching end point in gas phase etching, in particular with the aid of the etching gases ClF3 and/or BrF3, or in the anisotropic plasma etching of silicon substrates. In addition, a method is provided for etching a semiconductor element using a gaseous etching medium, during which the speed of removal of the semiconductor element is set or changed via a setting of the polarity and/or the density of free load carriers in the semiconductor element. In addition, a device for etching a semiconductor element, which device is suitable for carrying out the two methods described above, is provided.

Dependencies are inferred from the claim text.