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:
Aug. 28, 2001
Filed:
Sep. 14, 1999
Chih Ming Chen, Hsinchu, TW;
Abstract
A method for embedded flash cell fabrication beyond 0.35 &Xgr;m generation. First, a relatively thick field oxide layer is formed on the P-type substrate to separate the flash cell areas and logic cell area. The flash cell areas are divided into tunnel oxide window and capacitor coupling area. Next, a conventional photolithogrpahy and etching method is used to formed a patterned photoresist on the substrate and expose flash cell areas. Then N-type conductive dopants are implanted into the substrate. For 0.35 &mgr;m generation, the concentration of dopant is increased to 5El7˜1El9 atoms/cm,. Next, the patterned photoresist layer are removed and thicker tunnel oxide and thinner gate oxide layer are formed in one processing step. Next, a doped polysilicon layer is deposited by using a conventional chemical vapor deposition over the tunnel oxide layer to serve as the floating gate of the flash cell.