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:
Jan. 16, 2001
Filed:
Dec. 11, 1998
Robert Bosch GmbH, Stuttgart, DE;
Abstract
A method of producing an optical waveguide, in which a substrate of silicon is etched porously to a defined depth by anodic oxidation in an electrolyte containing hydrofluoric acid. The etched substrate is doped in a suitable dopant liquid containing cations. The doped layer of porous silicon is stabilized at an elevated temperature, and the stabilized layer is oxidized with a further increase in temperature. The oxidized porous layer is made to collapse at a temperature sufficient for partial melting. The surface of the collapsed silicon dioxide layer is covered in a pattern by a lithographic technique, and the cations are replaced by silver ions in the uncovered areas of the surface by bringing the surface in contact with a solution containing silver ions or silver complex ions.