Patent ID: 7411253
Filing Date: 2008-08-12
Classification: H01L

Abstract:
1. A semiconductor device comprising: an n channel conductivity type field effect transistor including a channel forming region formed in a first region on a main surface of a semiconductor substrate, a gate electrode of the n channel conductivity type field effect transistor formed over the channel forming region of the n channel conductivity type field effect transistor, wherein the n channel conductivity type field effect transistor includes a source region and a drain region formed in the semiconductor substrate such that the channel forming region is formed between the source region and the drain region; and a p channel conductivity type field effect transistor including a channel forming region formed in a second region on a main surface, which second region is different from the first region, a gate electrode of the p channel conductivity type field effect transistor formed over the channel forming region of the p channel conductivity type field effect transistor, wherein the p channel conductivity type field effect transistor includes a source region and a drain region formed in the semiconductor substrate such that the channel forming region is formed between the source region and the drain region, wherein the gate electrode of the n channel conductivity type field effect transistor has an impurity concentration greater than an impurity concentration of the gate electrode of the p channel conductivity type field effect transistor such that the gate electrode of the n channel conductivity type field effect transistor generates a stress to create a tensile stress in the direction of flow of a drain current in the channel forming region of the n channel conductivity type field effect transistor, and wherein the tensile stress in the direction of flow of a drain current in the channel forming region of the n channel conductivity type field effect transistor is greater than a tensile stress in the direction of flow of a drain current in the channel forming region of the p channel conductivity type field effect transistor.