Filter element and method for the production thereof

A method for producing a filter element that includes the following successive steps:

• 1) application of a membrane layer to a carrier substrate,
• 2) etching a membrane chamber on the side of the carrier substrate opposite to the membrane layer, so that a residual layer of the carrier substrate still remains,
• 3) generation of pores in the membrane layer by means of a lithographic and etching process in order to create a perforated membrane,
• 4) removal of the residual layer of the membrane chamber by etching in order to expose the membrane layer of the membrane chamber, and
• 5) subjecting the membrane to an additional treatment in order to increase its mechanical strength, which additional treatment consists of one or more the following:
• 5.1) formation of crystal nuclei in the membrane layer in step 1,
• 5.2) heating temperature treatment of a structure of carrier layer and membrane layer in order to increase the crystalline fraction in the membrane layer in step 1 and/or after step 4,
• 5.3) isostatic hot pressing of the structure of carrier layer and membrane layer to increase the crystalline fraction in the membrane layer prior to step 3 or after step 4, and
• 5.4) generation of an internal prestress in the membrane layer in step 1 or after step 4.