Process for manufacturing a DMOS transistor

US6806131B2 · kind B2 · utility

Assignee

• ATMEL Germany GmbH · DE

Inventors

• Christoph Bromberger · Heilbronn, DE
• Franz Dietz · Heilbronn, DE
• Volker Dudek · Ditzingen, DE
• Michael Graf · Leutenbach, DE
• Joern Herrfurth · Heilbronn, DE
• Manfred Klaussner · Heilbronn, DE

Key dates

• Filing date: Jun 11, 2002
• Grant date: Oct 19, 2004
• Expiry date: Jun 11, 2022

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10D62/151
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

In a new process of making a DMOS transistor, the doping of the sloping side walls can be set independently from the doping of the floor region in a trench structure. Furthermore, different dopings can be established among the side walls. This is achieved especially by a sequence of implantation doping, etching to form the trench, formation of a scattering oxide protective layer on the side walls, and two-stage perpendicular and tilted final implantation doping. For DMOS transistors, this achieves high breakthrough voltages even with low turn-on resistances, and reduces the space requirement, in particular with regard to driver structures.