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:
Aug. 02, 2011
Filed:
Oct. 28, 2009
Sunil Mehta, San Jose, CA (US);
Stewart Logie, Campbell, CA (US);
Steven Fong, Santa Clara, CA (US);
Sunil Mehta, San Jose, CA (US);
Stewart Logie, Campbell, CA (US);
Steven Fong, Santa Clara, CA (US);
Lattice Semiconductor Corporation, Hillsboro, OR (US);
Abstract
In one embodiment, an integrated circuit includes a substrate having high voltage transistor regions and low voltage transistor regions. The substrate includes a first trench between and adjacent to the high voltage transistor regions, a second trench between and adjacent to the low voltage transistor regions, and a third trench between the first and second trenches and between and adjacent to a high voltage transistor region and a low voltage transistor region. A thicker silicon dioxide layer lines the first trench and a first portion of the third trench adjacent to a high voltage transistor region. A thinner silicon dioxide layer lines the second trench and a second portion of the third trench adjacent to a low voltage transistor region. A silicon nitride layer is present on the thinner silicon dioxide layer and lines the second trench and the second portion of the third trench but is not present on the thicker silicon dioxide layer and does not line the first trench and the first portion of the third trench.