Patent ID: 8525273
Filing Date: 2013-09-03
Classification: H01L

Abstract:
1. A semiconductor device comprising: a semiconductor substrate having a first voltage region configured to be driven at a first voltage and a second voltage region disposed adjacent to the first voltage region and configured to be driven at a second voltage; a first field effect transistor (FET) on the first voltage region and including a first gate insulating layer having a first thickness; a second FET on the second voltage region and including a second gate insulating layer having a second thickness; and a device isolation layer structure that electrically separates the first and second voltage regions, wherein the device isolation layer structure includes first and second trenches separated by a predetermined distance in the semiconductor substrate, electrically insulating layers respectively provided in the first and second trenches, and a guard ring region extending between the first and second trenches, wherein the guard ring region has a different conductivity type than respective wells of the first and/or second voltage regions.