Semiconductor device and method of manufacturing the same

A cell region of a semiconductor device includes a first and second isolation dummy gates extending along a first direction. The semiconductor device further includes a first gate extending along the first direction and between the first isolation dummy gate and the second isolation dummy gate. The semiconductor device includes a second gate extending along the first direction, the second gate being between the first isolation dummy gate and the second isolation dummy gate relative to a second direction perpendicular to the first direction. The semiconductor device also includes a first active region and a second active region. The first active region extending in the second direction between the first isolation dummy gate and the second isolation dummy gate. The first active region has a first length in the second direction, and the second active region has a second length in the second direction different from the first length.