Verfahren zum Herstellen eines Biosensors

A process for the production of a biosensor having a planarized surface which prevents the risk of tearing of biological or biochemical membranes, comprises the steps of generating isolator areas, generating a gate isolator, generating and structuring a polysilicon layer, implementing source and drain, stripping an active gate area, arranging the ISFET within a casing in such a way that the active gate area of the ISFET lies within a window of the casing, and applying the biological or biochemical membrane to the active gate area, whereby the drain and source of the ISFET pass over into diffusion conductors which extend from the active gate area to outside the window of the casing, whereby, according to the process step of generating the gate oxide layer, a nitride layer is deposited both on the gate oxide layer and on the field oxide area, and whereby, in the process step of stripping the active gate area, the layers outside the nitride layer in the area of the gate, source and drain of the ISFET and in the adjacent subareas of the field oxide areas, are removed by etching.