Method for anisotropic plasma etching of semiconductors

The present invention relates to a method of anisotropic etching of structures in a semiconductor body, in particular of recesses in a silicon body exactly defined laterally by an etching mask, by using a plasma according to the definition of the species of the main claim. A method of anisotropic etching of structures in a semiconductor body, in particular of recesses in a silicon body () exactly defined laterally by an etching mask, by using a plasma () is proposed. An ion acceleration voltage induced in particular by a high-frequency AC voltage is applied to the semiconductor body at least during an etching step having a predefined duration. The duration of the etching step is further subdivided into at least two etching segments between which the ion acceleration voltage applied is modified each time. Preferably two etching segments are provided, a higher acceleration voltage being used during the first etching segment than during the second etching step. The length of the first etching segment can furthermore be determined dynamically or statically during the etching steps using a device for the detection of a polymer breakdown. In order to generate and adjust the value of the acceleration voltage, preferably high-frequency pulses or pulse packets having an adjustable pulse/pause ratio are used.