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:
Oct. 07, 2003
Filed:
Nov. 30, 2000
Winbond Electronics Corporation, Hsinchu, CN;
Abstract
A field oxide device (FOD) useful for electrostatic discharge (ESD) protection and other applications. The FOD is characterized as being capable of achieving a relatively low breakdown voltage and capable of handling relatively high currents during an ESD event. In general, the FOD includes a zener junction to promote an earlier breakdown of the device. The zener junction also provides a planar-like breakdown region which makes it capable of handling relatively high currents. In particular, the FOD includes a p-doped substrate having a drain-side n+ diffusion region and a source-side n+ diffusion region which are separated by a field oxide. The FOD further includes a p+ doped region that interfaces with the drain-side n+ diffusion region to form a zener junction. The breakdown voltage of the FOD can be easily set by controlling the doping concentration and energy of the p+ doped region. The FOD may additionally include one or more n+ regions at the respective boundaries of the drain-side and source-side n+ diffusion regions to provide improved junction curvature. In addition to the field oxide interposed between the drain-side and source-side n+ diffusion regions, field oxides can be added respectively at the drain and source ends to provide isolation from other devices within an integrated circuit.