Semiconductor devices and methods for fabricating the same

Abstract

Semiconductor devices with improved performance and reliability and methods for forming the same are provided. The semiconductor devices include an active pattern extending in a first direction, gate structures spaced apart from each other in the first direction on the active pattern, a source/drain pattern on the active pattern, a source/drain contact on the source/drain pattern, and a contact liner extending along a sidewall of the source/drain contacts. A carbon concentration of the contact liner at a first point of the contact liner is different from a carbon concentration of the contact liner at a second point of the contact liner, and the first point is at a first height from an upper surface of the active pattern, the second point is at a second height from the upper surface of the active pattern, and the first height is smaller than the second height.