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:
Jun. 17, 2003
Filed:
Oct. 08, 2002
Chih-Feng Huang, Chu-Rei, TW;
Kuo-Su Huang, Hsin-Chu, TW;
Taiwan Semiconductor Manufacturing Company, Hsin-Chu, TW;
Abstract
The tradeoff between breakdown voltage and on-resistance for LDMOS devices has been improved by having two epitaxial N−regions instead of the single epitaxial N−region that is used by devices of the prior art. The resistivities and thicknesses of these two N−regions are chosen so that their mean resistivity is similar to that of the aforementioned single N−layer. A key feature is that the lower N−layer (i.e. the one closest to the P−substrate) has a resistivity that is greater than that of the upper N−layer. If these constraints are met, as described in greater detail in the specification, improvements in breakdown voltage of up to 60% can be achieved without having to increase the on-resistance. A process for manufacturing the device is also described.