Patent ID: 7288485

Claim:
A method for anisotropic plasma etching of a substrate, the method comprising: generating, with a plasma source that is configured to generate a high-frequency electromagnetic alternating field, a plasma having reactive species inside a chamber in a reaction region by the action of the alternating field upon an etching gas inserted into the reaction region and a passivating gas inserted into the reaction region; in the reaction region, inserting the etching gas predominantly into a first zone and inserting the passivating gas predominantly into a second zone; generating a reactive etching gas species in the first zone by using a plasma that is generated there, and generating reactive passivating gas species in the second zone by using a plasma that is generated there, whereby etching species and passivating species are generated at least largely independently of one another; and mixing the etching gas species and the passivating gas species with each other in a mixing region downstream from the reaction region before their action upon the substrate, wherein a quantity of the passivating gas that is used is minimized compared to a quantity of the etching gas.