A method for releasing a micromechanical structure. A substrate is provided. At least one micromechanical structural layer is provided above the substrate, wherein the micromechanical structural layer is sustained by a sacrificial layer of a silicon material. An amine-based etchant is provided to etch the silicon material. That is, during performing a post-cleaning procedure with an amine-based etchant, polymer residue and the sacrificial layer of silicon can be simultaneously removed without any additional etching processes.