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:
Apr. 24, 2001
Filed:
Jul. 14, 1999
Chih-Cheng Liu, Pan-Chiao, TW;
Chin-Hui Lee, Taipei, TW;
United Microelectronics Corp., Hsin-Chu, TW;
Abstract
The invention relates to an ion implantation method for adjusting the threshold voltage of MOS transistors. The MOS transistor is employed in a DRAM (dynamic random access memory) memory cell in a semiconductor wafer and comprises a substrate, a gate insulating layer positioned on the substrate, and a gate conducting layer with a rectangular-shaped cross section positioned on the gate insulating layer. The method comprises performing an ion implantation process at a predetermined dosage and ion energy to implant dopants through the gate conducting layer and gate insulating layer and deposit the dopants into the superficial portion of the substrate below the gate insulating layer.