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. 22, 2011
Filed:
Dec. 02, 2009
Yeeheng Lee, San Jose, CA (US);
Moses Ho, Campbell, CA (US);
Lingpeng Guan, Sunnyvale, CA (US);
Alpha and Omega Semiconductor, Inc., Sunnyvale, CA (US);
Abstract
A method is disclosed for making a substantially charge balanced multi-nano shell drift region (MNSDR) for superjunction semiconductor devices atop a base substrate. The MNSDR has numerous concentric nano shell members NSM, NSM, . . . , NSM(M>1) of alternating, substantially charge balanced first conductivity type and second conductivity type and with height NSHT. First, a bulk drift layer (BDL) is formed atop the base substrate. A substantially vertical cavity of pre-determined shape and size and with depth NSHT is then created into the top surface of BDL. The shell members NSM, NSM, . . . , NSMare successively formed inside the vertical cavity, initially upon its vertical walls then moving toward its center, so as to successively fill the vertical cavity till a residual space remains therein. A semi-insulating or insulating fill-up nano plate is then formed inside the residual space to fill it up.