Integrated circuit inductor structure and non-destructive etch depth measurement

摘要

A method for forming an electrical device structure in an integrated circuit comprises providing a substrate; forming a passivation layer thereon; forming a plurality of through holes in the passivation layer, the through holes; removing substrate material under the passivation layer by means of isotropic etching, thus forming at least a first cavity in the substrate beneath the plurality of through holes; forming a dielectric layer on top of the passivation layer to plug the through holes, thereby creating a membrane; and creating an electrical device, such as e.g. an inductor, above the membrane.