Manufacturing method of semiconductor device with filling insulating film into trench

A manufacturing method of a semiconductor device, comprising:

• forming a trench on a surface of a semiconductor substrate;
• forming a first silicon oxide film into the trench with a high density plasma;
• removing the first silicon oxide film formed on the surface until the surface is exposed;
• and
• forming a second silicon oxide film on the first silicon oxide film and on the exposed surface with a high density plasma.

A manufacturing method of a semiconductor device, comprising:

• forming an insulating film on a semiconductor substrate,
• forming a polysilicon film on the insulating film;
• forming a trench penetrating the insulating film and the polysilicon film and dug in the semiconductor substrate;
• forming a thermal oxide film on an internal surface of the trench by a oxidation of an oxygen radical;
• and
• filling a first silicon oxide film into the trench with a high density plasma.

A manufacturing method of a semiconductor device, comprising:

• forming an insulating film on a semiconductor substrate;
• forming a polysilicon film on the insulating film;
• forming a trench penetrating the insulating film and the polysilicon film and dug in the semiconductor substrate;
• forming a first thermal oxide film and a second thermal oxide film by a thermal oxidation of the semiconductor substrate and the polysilicon film on an internal surface of the trench,
• forming a first silicon oxide film on the first thermal oxide film and the second thermal oxide film with a high density plasma;
• removing the first silicon oxide film formed on an upper part of the second thermal oxide film;
• and
• forming a second silicon oxide film on the first silicon oxide film with a high density plasma.