Micromechanical system and method for manufacturing a micromechanical system

US9382111B2 · kind B2 · utility

Assignee

• Infineon Technologies Dresden GmbH & Co. KG · DE

Inventors

• Thoralf Kautzsch · Dresden, DE
• Heiko Froehlich · Radebeul, DE
• Mirko Vogt · Dresden, DE
• Maik Stegemann · Freital, DE
• Boris Binder · Dresden, DE
• Steffen Bieselt · Wehlen, DE

Key dates

• Filing date: Apr 27, 2015
• Grant date: Jul 5, 2016
• Expiry date: Apr 27, 2035

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B81C2203/0735
• WIPO field: Micro-structural and nano-technology
• WIPO sector: Chemistry

Abstract

A method for manufacturing a micromechanical system is shown. The method comprises the steps of forming in a front end of line (FEOL) process a transistor in a transistor region. After the FEOL process, a protective layer is deposited in the transistor region, wherein the protective layer comprises an isolating material, e.g. an oxide. A structured sacrificial layer is formed at least in a region which is not the transistor region. Furthermore, a functional layer is formed which is at least partially covering the structured sacrificial layer. After the functional layer is formed removing the sacrificial layer in order to create a cavity between the functional layer and a surface, where the sacrificial layer was deposited on. The protective layer protects the transistor from being damaged especially during etching processes in further processing steps in MOL (middle of line) and BEOL (back end of line) processes. Using an oxide for said protective layer is advantageous, since the same oxide may be used as the basis for a metallization process in the BEOL. Therefore, the protective layer may remain over the transistor and does not need to be removed like the sacrificial layer, which …