Method for manufacturing FDSOI

US11640923B2 · kind B2 · utility

Assignee

• Shanghai Huali Integrated Circuit Corporation · CN

Inventors

• Tianpeng Guan · Shanghai, CN
• Jianghua Leng · Shanghai, CN
• Zhonghua Li · Shanghai, CN
• Yufeng Chen · Lo Wu, CN
• Nan Li · Tianjin, CN
• Ming Tian · Nanhu, CN

Key dates

• Filing date: Sep 24, 2021
• Grant date: May 2, 2023
• Expiry date: Sep 24, 2041

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L21/02639
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

The present application provides a method for manufacturing FDSOI devices. The method includes steps of: providing a semiconductor structure which comprises a silicon substrate, a buried oxide layer on the silicon substrate, a silicon-on-insulator layer on the buried oxide layer; and a hard mask layer on the silicon-on-insulator layer; performing spin coating of a photoresist on the hard mask layer to form a bulk silicon region; performing plasma anisotropic etching on the bulk silicon region to open a part of the buried oxide layer, and then performing isotropic etching, so that the silicon-on-insulator layer shrinks in the horizontal direction; performing plasma anisotropic etching to etch through the buried oxide layer to form a bulk silicon region trench; performing silicon epitaxial growth in the bulk silicon region trench. The silicon-on-insulator layer is still shrinks after the bulk silicon region trench is formed, as the result, there is no bump on the surface of the silicon-on-insulator layer, thus the process window becomes controllable.