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:
Oct. 26, 2010
Filed:
Sep. 09, 2008
Chun-li Liu, Scottsdale, AZ (US);
Olin K. Hartin, Phoenix, AZ (US);
Jay P. John, Chandler, AZ (US);
Vishal P. Trivedi, Chandler, AZ (US);
James A. Kirchgessner, Tempe, AZ (US);
Chun-Li Liu, Scottsdale, AZ (US);
Olin K. Hartin, Phoenix, AZ (US);
Jay P. John, Chandler, AZ (US);
Vishal P. Trivedi, Chandler, AZ (US);
James A. Kirchgessner, Tempe, AZ (US);
Freescale Semiconductor, Inc., Austin, TX (US);
Abstract
An improved varactor diode () is obtained by providing a substrate () having a first surface (), in which are formed a P+ region () proximate the first surface (), a first N region () located beneath the P+ region (), an N well region () located beneath the first N region () and a first P counter-doped region () located between the first N region () and the N well region (), thereby forming an P+NPN structure for the varactor diode. In some embodiments, a second P-type counter-doped region () is provided within the N-well region () so as to reduce the N doping concentration within the N well region () but without creating a further PN junction therein. The net doping profile () provides varactor diodes () having a larger tuning ratio than varactors () without such counter-doped regions. By interchanging N and P regions an N+PNP varactor is obtained.