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. 17, 2007
Filed:
Jan. 11, 2005
Cheng-ming Yih, Hsin-Chu, TW;
Huei-huarng Chen, Chang-Hua, TW;
Hsuan-ling Kao, Taipei, TW;
Macronix International Co., Ltd., Hsin-Chu, TW;
Abstract
A method for forming a buried diffusion layer with reducing topography in a surface of a semiconductor substrate is provided. A patterned first dielectric layer is formed on a semiconductor substrate for being used as a first hard mask. A thermal oxidation process is performed to form field oxides on the exposed potions of the semiconductor substrate. The patterned first dielectric layer is then removed. A second patterned dielectric layer is formed on the field oxides and the semiconductor substrate for being used as a second hard mask. An isotropic etching process is performed to etch the exposed portions of the field oxides and the semiconductor substrate. The patterned second dielectric layer and the underlying field oxides are removed to form a plurality of trenches on the surface of the semiconductor substrate. A buried diffusion layer is formed along surroundings of the trenches in the semiconductor substrate.