MOS transistor having a recessed gate electrode and fabrication method thereof

摘要

A metal oxide semiconductor (MOS) transistor having a recessed gate electrode and a fabrication method thereof are provided. The MOS transistor includes a semiconductor substrate and an isolation layer formed in a predetermined region of the semiconductor substrate to define an active region. A channel trench region is disposed within the active region to cross the active region. A gate insulating layer is disposed to cover sidewalls and a bottom of the channel trench region. The MOS transistor has a gate pattern that fills the channel trench region and crosses above the active region. A portion of the sidewall of the gate pattern is recessed at an upper corner of the channel trench region and has a width smaller than the width of the top of the gate pattern and smaller than the width of the channel trench region.