Patent ID: 7301208
Filing Date: 2007-11-27
Classification: H01L

Abstract:
1. A semiconductor device, comprising: a gate electrode formed on a semiconductor substrate; source/drain regions of a first conductivity type formed in the semiconductor substrate at both sides of the gate electrode; a first doped layer of a second conductivity type opposite to that of the source/drain regions, the first doped layer being formed in the semiconductor substrate and located under the gate electrode; and a second doped layer of the second conductivity type opposite to that of the source/drain regions, the second doped layer being formed in the semiconductor substrate and located below the first doped layer, wherein the first doped layer has a first peak in dopant concentration distribution in a depth direction, the first peak is located at a position shallower than a junction depth of the source/drain regions, the second doped layer has a second peak in dopant concentration distribution in a depth direction, the second peak is located at a position deeper than the first peak and shallower than the junction depth of the source/drain regions, and a dopant concentration at the first peak is higher than that at the second peak, wherein the dopant concentration at the first peak of the first doped layer is equal to or higher than 5×10