Semiconductor device having super junction structure and method for manufacturing the same

A semiconductor device having a super junction structure comprising:

• a plurality of first columns having a first conductive type and extending in a current flowing direction;
• and
• a plurality of second columns having a second conductive type and extending in the current flowing direction, wherein
• the first columns and the second columns are alternately arranged in an alternating direction perpendicular to the current flowing direction so that the super junction structure is provided,
• each first column provides a drift layer in case of an on-state for flowing a current therein,
• the first columns and the second columns have a boundary between the first column and the second column, from which a depletion layer expands in case of an off-state, and
• at least one of the first columns and the second columns have an impurity dose, which is inhomogeneous by location with respect to the current flowing direction.

A method for manufacturing a semiconductor device having a super junction structure, the method comprising:

• preparing a semiconductor substrate having a first conductive type;
• forming a plurality of trenches in the substrate, wherein each trench has a constant width along with a first direction, and wherein a distance between neighboring two trenches along with the first direction includes at least a first distance and a second distance;
• forming an epitaxial film having a second conductive type on the substrate so that the trenches are filled with the epitaxial film;
• and
• flattening one side of the substrate, on which the epitaxial film is formed.

A semiconductor device having a super junction structure comprising:

• a plurality of first columns having a first conductive type and extending in a current flowing direction;
• and
• a plurality of second columns having a second conductive type and extending in the current flowing direction, wherein
• the first columns and the second columns are alternately arranged in an alternating direction perpendicular to the current flowing direction so that the super junction structure is provided,
• each first column provides a drift layer in case of an on-state for flowing a current therethrough,
• the first columns and the second columns have a boundary between the first column and the second column, from which a depletion layer expands in case of an off-state,
• each of the first columns and the second columns have a stripe planar pattern on a plane perpendicular to the current flowing direction, and
• at least one of the first columns and the second columns have a bridge portion, which connects one first or second column and a neighboring first or second column.

A method for manufacturing a semiconductor device having a super junction structure, the method comprising:

• preparing a semiconductor substrate having a first conductive type;
• forming a plurality of trenches in the substrate, wherein each trench has a constant width along with a first direction, wherein the trenches have a constant distance between neighboring two trenches along with the first direction, and wherein each trench extends intermittently in a second direction, which is perpendicular to the first direction;
• and
• forming an epitaxial film having a second conductive type on the substrate so that the trenches are filled with the epitaxial film.