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:
Nov. 13, 2001
Filed:
Feb. 21, 2000
Kun-Chi Lin, Hsin-Chu, TW;
Abstract
A method for forming a cell passes transistor in DRAM process disclosed. In one embodiment, the present invention provides a MOS structure, which can reduce junction leakage for P/N junction and increase the refreshes time capability. A method for DRAM fabrication comprises providing a semiconductor substrate having at least an isolation device therein. The isolation device defines an active area adjacent thereto on the semiconductor substrate. A first photoresist layer is formed on the semiconductor substrate, which exposes the active area in a first direction. The first conductive ions are implanted to form a well region in the semiconductor substrate, and the second conductive ions are implanted to form a field implant region in the semiconductor substrate. The third conductive ions are implanted to form a punchthrough implant region in the semiconductor substrate. Then the first photoresist layer is removed, and a second photoresist layer is formed on the semiconductor substrate. The second photoresist layer exposes the active area in a second direction different from the first direction. The fourth conductive ions are implanted to form a threshold implant region, and then the second photoresist layer is removed.