Method for manufacturing a micromechanical diaphragm structure having access from the rear of the substrate

US8519494B2 · kind B2 · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Torsten Kramer · Wannweil, DE
• Marcus Ahles · Pfullingen, DE
• Armin Grundmann · Jena, DE
• Kathrin Knese · Reutlingen, DE
• Hubert Benzel · Neckartenzlingen, DE
• Gregor Schuermann · Reutlingen, DE
• Simon Armbruster · Wannweil, DE

Key dates

• Filing date: Apr 21, 2009
• Grant date: Aug 27, 2013
• Expiry date: Oct 15, 2029

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B81C2201/0136
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A method for manufacturing a micromechanical diaphragm structure having access from the rear of the substrate includes: n-doping at least one contiguous lattice-type area of a p-doped silicon substrate surface; porously etching a substrate area beneath the n-doped lattice structure; producing a cavity in this substrate area beneath the n-doped lattice structure; growing a first monocrystalline silicon epitaxial layer on the n-doped lattice structure; at least one opening in the n-doped lattice structure being dimensioned in such a way that it is not closed by the growing first epitaxial layer but instead forms an access opening to the cavity; an oxide layer being created on the cavity wall; a rear access to the cavity being created, the oxide layer on the cavity wall acting as an etch stop layer; and the oxide layer being removed in the area of the cavity.