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:
Dec. 14, 1999
Filed:
Feb. 13, 1998
Wen-Cheng Chien, Kao-Hsiung, TW;
Ming-Yi Lin, Hsin-Chu, TW;
Li-Ming Huang, Taipei, TW;
Chen-Peng Fan, Hsin Chu Hsien, TW;
Taiwan Semiconductor Manufacturing Company, Ltd., Hsin-Chu, TW;
Abstract
A method is provided for forming nitride spacers for flash EEPROM devices. A silicon nitride layer is formed over the floating gate in a memory cell. Unlike in conventional methods where the nitride layer is usually subjected to anisotropic etching, it is disclosed in this invention that when partial isotropic/anisotropic etching of a particular recipe is performed, the resulting nitride spacers are better controlled dimensionally with the attendant advantage, therefore, of better definition of gate and channel lengths during subsequent implantations. In a second embodiment, the partial isotropic/anisotropic etching is followed by full anisotropic etching of another recipe with even better defined parameters for the flash EEPROMS.