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:
Jan. 21, 2003
Filed:
May. 10, 2001
Liping Ren, Los Angeles, CA (US);
Srikant Sridevan, Redondo Beach, CA (US);
International Rectifier Corporation, El Segundo, CA (US);
Abstract
A process is described for making a superjunction semiconductor device, a large number of symmetrically spaced trenches penetrate the N epitaxial layer of silicon atop an N body to a depth of 35 to 40 microns. The wells have a circular cross-section and a diameter of about 9 microns. The trench walls are implanted by an ion implant beam of boron which is at a slight angle to the axis of the trenches. The wafer is intermittently or continuously rotated about an axis less than 90° to its surface to cause skewing of the implant beam and more uniform distribution of boron ions over the interior surfaces of the trenches.