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:
Feb. 01, 1994
Filed:
Aug. 22, 1991
Hans-Peter Trah, Reutlingen, DE;
Guenther Findler, Stuttgart, DE;
Robert Bosch GmbH, Stuttgart, DE;
Abstract
A method for anisotropically etching recesses in a monocrystalline disk-shaped wafer is proposed, by which structural elements such as membranes or through openings can be made in the wafer. To this end, a mask layer is applied to a first surface of the wafer and subsequently structured by making at least one opening in the mask layer. The dimensioning of the at least one opening, and its orientation with respect to the crystal orientation of the wafer and to the anisotropic properties of the wafer material, are selected such that the desired size and shape of the area of the recess or outlet hole are attained by anisotropic etching into the wafer through the at least one opening in the mask layer and by purposeful underetching of the mask layer.