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:
Aug. 24, 2004
Filed:
Jun. 11, 2002
Christoph Bromberger, Leingarten, DE;
Franz Dietz, Heilbronn, DE;
Volker Dudek, Korntal-Muenchingen, DE;
Michael Graf, Leonberg, DE;
Joern Herrfurth, Heilbronn, DE;
Manfred Klaussner, Heilbronn, DE;
ATMEL Germany GmbH, Heilbronn, DE;
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.