Method of manufacturing semiconductor device

A method of manufacturing a semiconductor device, comprising:

• forming a first recess in a semiconductor substrate to define an active region on the semiconductor substrate, the active region including a protruding portion of the semiconductor substrate surrounded by the first recess, and the protruding portion having a sloped side surface;
• forming a first insulating film that fills the first recess;
• forming a gate recess in the active region to form a thin film portion that upwardly extends, the thin film portion being positioned between the gate recess and the first insulating film, the thin film portion being a part of the protruding portion;
• and
• removing an upper part of the thin film portion by wet-etching to adjust a height of the thin film portion,
• wherein the upper part of the thin film portion is removed by using phosphoric acid solution as a wet-etching solution.

A method of manufacturing a semiconductor device, comprising:

• forming a first recess in a semiconductor substrate to define an active region on the semiconductor substrate, the active region including a first protruding portion of the semiconductor substrate surrounded by the first recess;
• forming a mask insulating film on a side surface of the first protruding portion;
• forming a second recess under the first recess using the mask insulating film as a part of a dry-etching mask to form a second protruding portion under the first protruding portion, the second protruding portion having a sloped side surface, and the active region including the second protruding portion of the semiconductor substrate surrounded by the second recess;
• forming a first insulating film filling the first and second recesses;
• forming a gate recess in the active region to form a thin film portion that upwardly extends, the thin film portion being positioned between the gate recess and the first insulating film, the thin film portion being a part of the second protruding portion, and a bottom surface of the gate recess reaching to the second protruding portion;
• and
• removing an upper part of the thin film portion by wet-etching to adjust a height of the thin film portion,
• wherein the upper part of the thin film portion is removed by using pure water as a solution for the wet-etching.

A method of manufacturing a semiconductor device, comprising:

• forming a recess in a semiconductor substrate to form a thin film portion, the semiconductor substrate having a sloped side surface, the thin film portion being a part of the semiconductor substrate, and the thin film portion upwardly extending along a side surface of the recess;
• and
• removing an upper part of the thin film portion by wet-etching to adjust a height of the thin film portion,
• wherein the upper part of the thin film portion is removed by using pure water as a solution for the wet-etching.

A method of manufacturing a semiconductor device, comprising:

• forming a recess in a semiconductor substrate to form a thin film portion, the semiconductor substrate having a sloped side surface, the thin film portion being a part of the semiconductor substrate, and the thin film portion upwardly extending along a side surface of the recess;
• and
• removing an upper part of the thin film portion by wet-etching to adjust a height of the thin film portion,
• wherein the upper part of the thin film portion is removed by using pure phosphoric acid solution as a solution for the wet-etching.