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:
Mar. 05, 2013
Filed:
Mar. 10, 2011
Yimin Wang, Camas, WA (US);
Yimin Wang, Camas, WA (US);
Wafertech, LLC, Camas, WA (US);
Abstract
Methods for forming split gate flash cell structures provide for symmetrical cells that are immune to misalignment of the photoresist pattern when forming the control gates. Spacers are utilized to form the floating gates in the floating gate transistors used in the flash cells. The spacers may be oxide spacers used to mask a polysilicon layer that will form the floating gates or the spacers may be polysilicon spacers that will themselves form the floating gates. The inter-gate oxide of the floating gate transistors may be formed using HTO or may be deposited. Hard mask spacers are used in conjunction with the control gate photoresist patterning operation to control the size and configuration of the control gate and the channel length.