To electrically short an active region of a Metal-Oxide-Semiconductor (MOS) device to a gate electrode strip, a butted contact plug may be formed to interconnect the active region and the gate electrode strip. Conventionally, the active region and the gate electrode strip were connected to electrical ground for device isolation purpose.
In the conventional structures, the gate electrode strip that was used for the device isolation was formed over a Shallow Trench Isolation (STI) region. The STI region requires more chip area than the gate electrode strip. This causes the adverse reduction in the device density.