US Patent 11183395 Semiconductor device and fabrication method thereof

A semiconductor device and its fabrication method are provided. The method includes forming a core layer on a first region of a base substrate layer; forming sidewall spacer layers on sidewalls of two sides of the core layer along a first direction; forming a filling layer on a second region between adjacent sidewall spacer layers which are arranged along the first direction; forming a first dividing trench in the filling layer on the second region to divide the filling layer along a second direction, where sidewalls of the first dividing trench, arranged along the first direction, expose corresponding sidewall spacer layers; forming a second dividing trench in the core layer to divide the core layer along the second direction; forming a second dividing layer in the second dividing trench when forming a first dividing layer in the first dividing trench; and removing the filling layer and the core layer.