The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 30, 2004
Filed:
Oct. 25, 1999
Klaus Heyers, Reutlingen, DE;
Wilhelm Frey, Stuttgart, DE;
Robert Bosch GmbH, Stuttgart, DE;
Abstract
A process for manufacturing a membrane sensor over a silicon substrate, preferably a thermal membrane sensor. A thin layer of silicon carbide or silicon nitride is deposited over an area of porous silicon formed in the surface of the substrate, and then openings that extend as far as the layer of porous silicon are formed in the silicon carbide or silicon nitride layer via a dry etching process. Next, semiconductor structures and conductor path structures are implanted into the upper surface of the membrane layer via lithographic steps, and then the sacrificial layer of porous silicon is removed using a suitable solvent such as ammonia. Thus an empty space that thermally isolates the sensor membrane from the substrate is created beneath the membrane layer.