US Patent 7105397 Semiconductor device and method of fabricating the same

According to the present invention, there is a provided a semiconductor device fabrication method having, forming a mask material in a surface portion of a semiconductor substrate, and forming a step having a projection by using the mask material; forming a dielectric film on the semiconductor substrate so as to fill the step and planarize an entire surface; annealing the dielectric film; etching back the dielectric film such that a surface of the dielectric film is positioned between upper and lower surfaces of the mask material; and removing the mask material to expose a surface of the projection of the semiconductor substrate.