Semiconductor device and method for manufacturing same

A method for manufacturing a semiconductor device, comprising:

• forming a hard mask material film on a semiconductor substrate;
• forming an opening in the hard mask material film and forming a recess in an upper surface of the semiconductor substrate immediately below the opening by etching;
• forming a second-conductivity-type region in the semiconductor substrate immediately below the recess by implanting impurities using the hard mask material film as a mask;
• burying a dielectric material in the opening and in the recess;
• forming a half-buried dielectric film having a lower portion buried in the semiconductor substrate and an upper portion protruding from the upper surface of the semiconductor substrate by removing the hard mask material film;
• and
• forming a first-conductivity-type region in a region of the semiconductor substrate being in contact with the second-conductivity-type region by implanting impurities using the half-buried dielectric film as a mask.

A method for manufacturing a semiconductor device, comprising:

• forming a first hard mask material film on a semiconductor substrate;
• forming an opening in the first hard mask material film and forming a recess in an upper surface of the semiconductor substrate immediately below the opening by etching;
• removing the first hard mask material film;
• forming a second hard mask material film on the semiconductor substrate and on an inner surface of the recess;
• forming a second-conductivity-type region in the semiconductor substrate immediately below the recess by implanting impurities using the second hard mask material film as a mask;
• burying a dielectric material in the opening and in the recess;
• forming a half-buried dielectric film, which has a lower portion buried in the semiconductor substrate and an upper portion protruding from the upper surface of the semiconductor substrate, and a buffer dielectric film, which covers a portion of the half-buried dielectric film buried in the recess, by removing the second hard mask material film deposited on the upper surface of the semiconductor substrate and leaving the second hard mask material film deposited on the inner surface of the recess;
• and
• forming a first-conductivity-type region in a region of the semiconductor substrate being in contact with the second-conductivity-type region by implanting impurities using the half-buried dielectric film as a mask.