Integrated circuit inductor structure and non-destructive etch depth measurement
AssigneeTelefonaktiebolaget LM Ericsson (publ)
InventorsHans Norström, Carl Björmander, Ted Johansson
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Abstract
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.
Claims23
In the fabrication of an integrated circuit, particularly an integrated circuit for radio frequency applications, a method for forming an electrical device structure comprised in said circuit, the method comprising:
- providing a semiconductor substrate;
- forming a first dielectric layer above said substrate;
- forming a plurality of through holes in said first dielectric layer;
- removing semiconductor substrate material under the first dielectric layer by means of isotropic etching using said first dielectric layer provided with through holes as hardmask, thus forming at least a first cavity in the semiconductor substrate underneath said plurality of through holes;
- forming a second dielectric layer on top of said first dielectric layer to plug said plurality of through holes, thereby creating a membrane above said first cavity;
- and
- creating an electrical device above said membrane.
Dependencies are inferred from the claim text.