Process for producing surface micromechanical structures

Abstract

A method for fabricating surface-micromechanical structures wherein a sacrificial layer, in particular of silicon oxide, is deposited on a silicon substrate represented by a silicon wafer, the sacrificial layer being patterned. Onto the sacrificial layer, a second layer, in particular of polysilicon, is deposited and is likewise patterned. The sacrificial layer is removed in an etching operation by means of an etching medium which attacks the sacrificial layer but not the second layer, structures being formed as a result of which are free-standing above the silicon substrate at a distance equal to the thickness of the removed sacrificial layer and are anchored at certain sites on the silicon substrate. According to the invention, for the purpose of etching and exposing, the micromechanical structures are exposed to the vapor phase of a mixture of anhydrous hydrofluoric acid and water in a vapor-phase etching process. This makes it possible to dispense with laborious rinsing operations and sublimation operations.

Dependencies are inferred from the claim text.