Patent ID: 7381989
Filing Date: 2008-06-03
Classification: H01L

Abstract:
1. A semiconductor device, comprising: a lower transistor comprising first and second lower source/drain regions formed on a semiconductor substrate; a lower interlevel insulation film formed on the semiconductor substrate and covering the lower transistor; an upper transistor comprising first and second upper source/drain regions formed on the lower interlayer insulation film over the lower transistor; an upper interlevel insulation film formed on the lower interlevel insulation film and covering the upper transistor; a silicon epitaxial layer formed in an epitaxial contact hole formed in the lower interlevel insulating film to expose the first lower source/drain region; a contact plug comprising a first material and formed in contact with the second lower source/drain region and the second upper source/drain region; and an extension layer comprising a second material different from the first material and formed in contact with a lateral face of the second upper source/drain region to enlarge an area of contact between the second upper source/drain region and a side surface of the contact plug.