Method for manufacturing semiconductor device

A method for manufacturing a semiconductor device, the method comprising:

• forming a buffer film on a semiconductor substrate;
• forming a mask having a trench formation pattern on the buffer film;
• forming an element partitioning trench corresponding to the trench formation pattern with the mask;
• and
• oxidizing a surface of the element partitioning trench to form an oxidized film on the surface of the element partitioning trench, wherein prior to said oxidizing, the buffer film is removed from a top edge of the element partitioning trench by a distance represented by the expression:
• 0≦x≦(d/2 sin θ)
• where x represents the removed distance of the buffer film, θ represents an angle between a plane parallel to the semiconductor substrate and a side surface of the element partitioning trench, and d represents a thickness of the oxidized film.

A method for manufacturing a semiconductor device, the method comprising:

• forming an element partitioning trench on a semiconductor substrate with a mask;
• filling the element partitioning trench with an insulative material;
• heat treating, after said filling operation, the insulative material to increase etching resistance of the insulative material;
• removing the mask after said heat treating operation;
• and
• forming a drive element on the semiconductor substrate.

A method for manufacturing a semiconductor device comprising:

• forming an element partitioning trench on a semiconductor substrate;
• filling an insulative material in the element partitioning trench;
• and
• heat treating the insulative material in a plurality of steps to reduce stress that is produced by volume change of the insulative material, wherein one step includes exposing the insulative material to a first atmosphere at a first temperature for a first predetermined period, and another step includes exposing the insulative material in a second atmosphere at a second temperature for a second predetermined period, the second temperature being higher than the first temperature.

A method for manufacturing a semiconductor device comprising:

• forming an element partitioning trench on a semiconductor substrate;
• filling an insulative material in the element partitioning trench;
• heat treating the insulative material in a plurality of steps, wherein one step includes exposing the insulative material to a first atmosphere at a first temperature for a predetermined period, and another step includes exposing the insulative material in a second atmosphere at a second temperature for a second predetermined period, the second temperature being higher than the first temperature;
• and
• flattening an upper surface of the insulative material.

A method for manufacturing a semiconductor device comprising:

• forming a buffer film on a semiconductor substrate;
• forming a mask having a trench formation pattern on the buffer film;
• forming an element partitioning trench corresponding to the trench formation pattern with the mask;
• acid-washing a surface of the element partitioning trench, wherein said acid-washing removes part of the buffer film that is adjacent to the element partitioning trench, the buffer film being inwardly removed by a predetermined distance from a top edge of the element partitioning trench;
• and
• oxidizing the surface of the element partitioning trench to form an oxidized film on the surface, wherein a condition of said acid-washing and a condition of said oxidizing are determined so that the predetermined distance is less than or equal to one half of a thickness of the oxidized film that is measured along a surface parallel to the semiconductor substrate.

A method for manufacturing a semiconductor device, the method compromising:

• forming a buffer film on a semiconductor substrate;
• forming a mask having a trench formation pattern on the buffer film;
• forming an element partitioning trench corresponding to the trench formation pattern with the mask;
• and
• oxidizing a surface of the element partitioning trench to form an oxidized film on the surface, wherein prior to said oxidizing, an end of the buffer film is removed from a top edge of the element partitioning trench by an adjusted distance that is less than or equal to one half of a thickness of the oxidized film along a plane parallel to the semiconductor substrate.