SEMICONDUCTOR DEVICE

A semiconductor device includes a substrate including a first region and a second region; a first transistor on the first region and including a first semiconductor pattern protruding from the first region, a first gate structure covering an upper surface and sidewalls of the first semiconductor pattern, and a first source/drain layer on an opposite side of the first gate structure and on the first semiconductor pattern, wherein the upper surface of the first source/drain layer is closer to the substrate than the uppermost surface of the first gate structure; and a second transistor on the second region and including a second semiconductor pattern protruding from the second region, a second gate structure covering a sidewall of the second semiconductor pattern, a second source/drain layer under the second semiconductor pattern, and a third source/drain layer on the second semiconductor pattern, wherein the upper surface of the first region is lower than the upper surface of the second region. 一种半导体器件包括：基板，包括第