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:
May. 25, 2010
Filed:
Jul. 24, 2008
Chai Ean Gill, Chandler, AZ (US);
Changsoo Hong, Phoenix, AZ (US);
James D. Whitfield, Gilbert, AZ (US);
Rouying Zhan, Gilbert, AZ (US);
Chai Ean Gill, Chandler, AZ (US);
Changsoo Hong, Phoenix, AZ (US);
James D. Whitfield, Gilbert, AZ (US);
Rouying Zhan, Gilbert, AZ (US);
Freescale Semiconductor, Inc., Austin, TX (US);
Abstract
An improved lateral bipolar electrostatic discharge (ESD) protection device () comprises a semiconductor (SC) substrate (), an overlying epitaxial SC layer (), emitter-collector regions () laterally spaced apart by a first distance () in the SC layer, a base region () adjacent the emitter region () extending laterally toward and separated from the collector region () by a base-collector spacing () that is selected to set the desired trigger voltage Vt. By providing a buried layer region () under the emitter region () Ohmically coupled thereto, but not providing a comparable buried layer region () under the collector region (), an asymmetrical structure is obtained in which the DC trigger voltage (Vt) and transient trigger voltage (Vt) are closely matched so that |Vt−Vt|˜0. This close matching increases the design margin and provides a higher performance ESD device () that is less sensitive to process variations, thereby improving manufacturing yield and reducing cost.