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:
Feb. 03, 2004
Filed:
Nov. 02, 2001
Anders Söderbärg, Norrtälje, SE;
Peter Olofsson, Stenhamra, SE;
Andrej Litwin, Danderyd, SE;
Telefonaktiebolaget LM Ericsson, Stockholm, SE;
Abstract
The invention relates to a method for forming a high voltage NMOS transistor together with a low voltage NMOS transistor and a low voltage PMOS transistor, respectively, in an n-well CMOS process by adding solely two additional process steps to a conventional CMOS process: (i) a masking step, and (ii) an ion implantation step for forming a doped channel region for the high voltage MOS transistor in the substrate self-aligned to the edge of the high voltage MOS transistor gate region. The ion implantation is performed through the mask in a direction, which is inclined at an angle to the normal of the substrate surface, to thereby create the doped channel region partly underneath the gate region of the high voltage MOS transistor.