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:
Jul. 30, 2019
Filed:
Sep. 24, 2015
Littelfuse, Inc., Chicago, IL (US);
Kyoung Wook Seok, Milpitas, CA (US);
Littelfuse, Inc., Chicago, IL (US);
Abstract
An IGBT includes a floating P well and a floating N+ well that extends down into the floating P well. A bottom surface of the floating P well has a waved contour with thinner portions and thicker portions. When the device is on, electrons flow laterally from an N+ emitter and through a channel region. Some electrons pass downward, but others pass laterally through the floating N+ well to one of the thinner portions of the floating P type well. The electrons then pass down from the thinner portions into the N− drift layer. Other electrons pass farther through the floating N+ well to subsequent, thinner electron injector portions of the floating P type well and then into the N− drift layer. The extra electron injection afforded by the waved floating well structure reduces V. The waved contour is made without adding any masking step to the IGBT manufacturing process.