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. 12, 2022
Filed:
Sep. 22, 2020
United Microelectronics Corporation, Hsinchu, TW;
Ming-Shing Chen, Tainan, TW;
UNITED MICROELECTRONICS CORPORATION, Hsinchu, TW;
Abstract
A method for fabricating flash memory is provided. A plurality of floating gate structures is formed on a gate dielectric layer in the memory device region of a substrate. The protective spacers are formed on two opposite sidewalls of each floating gate structure. A polysilicon gate structures are formed on the logic device region and a polysilicon control gate structure with an opening are formed on the memory device region to cover two adjacent floating gate structures, wherein the two protective spacers facing each other between two adjacent floating gate structures are exposed by the opening, and then the exposed protective spacer are removed. An ion implantation is performed on the substrate to form a source region between the two adjacent floating gate structures on each cell area. There will be no polysilicon material residue in the memory device region or pitting/undercutting phenomenon in the logic device region.