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:
Dec. 25, 2007
Filed:
Mar. 08, 2005
Akio Kitamura, Nagano, JP;
Akio Kitamura, Nagano, JP;
Abstract
A method of manufacturing a lateral trench-type MOSFET exhibiting a high breakdown voltage and including an offset drain region around a trench. Specifically, impurity ions are irradiated obliquely to the side wall of a trench to implant the impurity ions only into to the portion of a semiconductor substrate along the side wall of trench, impurity ions are irradiated in parallel to the side wall of trench to implant the impurity ions only into to the portion of semiconductor substrate beneath the bottom wall of trench; the substrate is heated to drive the implanted impurity ions to form an offset drain region around trench and to thermally oxidize semiconductor substrate to fill the trench 2 with an oxide. Alternatively, the semiconductor substrate is oxidized to narrow trench with oxide films leaving a narrow trench and the narrow trench left is filled with an oxide. Still alternatively, a plurality of trenches is formed, the trenches are filled with an oxide and the extended portion of semiconductor substrate extended between the adjacent trenches is converted to an oxide film by thermal oxidation.