Method of manufacturing semiconductor device having trench filled up with gate electrode

A semiconductor device comprising:

• a semiconductor substrate having a principal surface and a back surface being an opposite surface of the principal surface;
• a base region of a first conductivity type provided in the semiconductor substrate and extending from the principal surface in a first direction perpendicular to the principal surface;
• a source region of a second conductivity type provided in the base region and extending from the principal surface in the first direction;
• a drift region provided in the semiconductor substrate at an opposite side of the base region with respect to the source region;
• a drain region of the second conductivity type provided in the semiconductor substrate at a location remote from the base region;
• a trench dug from the principal surface, extending in the first direction, and penetrating the base region from the source region in a second direction;
• a gate insulating film provided on a surface of the trench;
• a gate electrode filling the trench through the gate insulating film;
• a source electrode electrically connected to the source region and the base region;
• and
• a drain electrode electrically connected to the drain region,
• wherein the drift region, the base region and the source region respectively have impurity concentrations, each of which is uniform in both the first direction and the second direction.

A semiconductor device comprising:

• a semiconductor substrate having a principal surface and a back surface being an opposite surface of the principal surface;
• a base region of a first conductivity type provided in the semiconductor substrate and extending from the principal surface in a first direction perpendicular to the principal surface;
• a source region of a second conductivity type provided in the base region and extending from the principal surface in the first direction;
• a drift region provided in the semiconductor substrate at an opposite side of the base region with respect to the source region;
• a drain region of the second conductivity type provided in the semiconductor substrate at a location remote from the base region;
• a trench dug from the principal surface and penetrating the base region from the source region in a second direction parallel to the principal surface;
• a gate insulating film provided on a surface of the trench;
• a gate electrode filling the trench through the gate insulating film;
• a source electrode electrically connected to the source region and the base region;
• a drain electrode electrically connected to the drain region;
• and
• a channel region formed in a portion of the base region adjoining the trench when so that a current flows in the channel region in the first direction when a voltage is applied to the gate electrode, the channel region having a width in the first direction that corresponds to a depth direction of the trench.

A semiconductor device comprising:

• a semiconductor substrate having a principal surface and a back surface at an opposite side of the principal surface;
• a base region of a first conductivity type provided in the semiconductor substrate and extending from the principal surface in a first direction perpendicular to the principal surface;
• an emitter region of a second conductivity type provided in the base region and extending from the principal surface in the first direction;
• a low concentration collector region of the second conductivity type provided in the semiconductor substrate at an opposite side of the base region with respect to the emitter region;
• a collector region of the first conductivity type provided in the semiconductor substrate at a location remote from the base region;
• a trench dug from the principal surface and penetrating the base region from the emitter region, in a second direction parallel to the principal surface;
• a gate insulating film provided on a surface of the trench;
• a gate electrode filling the trench through the gate insulating film;
• an emitter electrode electrically connected to the emitter region and the base region;
• and
• a collector electrode electrically connected to the collector region,
• wherein the low concentration collector region, the base region and the emitter region respectively have impurity concentrations, each of which is uniform in both the first direction and the second direction.

A semiconductor device comprising:

• a semiconductor substrate having a principal surface and a back surface at an opposite side of the principal surface;
• a base region of a first conductivity type provided in the semiconductor substrate and extending from the principal surface in a first direction perpendicular to the principal surface;
• an emitter region of a second conductivity type provided in the base region and extending from the principal surface in the first direction;
• a low concentration collector region of the second conductivity type provided in the semiconductor substrate at an opposite side of the base region with respect to the emitter region;
• a collector region of the first conductivity type provided in the semiconductor substrate at a location remote from the base region;
• a trench dug from the principal surface, extending in the first direction from the principal surface, and penetrating the base region from the emitter region in a second direction;
• a gate insulating film provided on a surface of the trench;
• a gate electrode filling the trench through the gate insulating film;
• an emitter electrode electrically connected to the emitter region and the base region;
• and
• a collector electrode electrically connected to the collector region,
• wherein the low concentration collector region, the base region and the emitter region respectively have impurity concentrations, each of which is uniform in both the first direction and the second direction.

A semiconductor device comprising:

• a semiconductor substrate having a principal surface and a back surface at an opposite side of the principal surface;
• a base region of a first conductivity type provided in the semiconductor substrate and extending from the principal surface in a first direction perpendicular to the principal surface;
• an emitter region of a second conductivity type provided in the base region and extending from the principal surface in the first direction;
• a low concentration collector region of the second -conductivity type provided in the semiconductor substrate at an opposite side of the base region with respect to the emitter region;
• a collector region of the first conductivity type provided in the semiconductor substrate at a location remote from the base region;
• a trench dug from the principal surface and penetrating the base region from the emitter region in a second direction;
• a gate insulating film provided on a surface of the trench;
• a gate electrode filling the trench through the gate insulating film;
• an emitter electrode electrically connected to the emitter region and the base region;
• a collector electrode electrically connected to the collector region;
• and
• a channel region formed in a part of the base region adjoining the trench when a voltage is applied to the gate electrode, the channel region having a width in the first direction and allowing a current to flow in therein in the second direction.

A semiconductor device comprising:

• a semiconductor substrate of a first conductivity type, having a principal surface and a back surface at an opposite side of the principal surface;
• a source region of a second conductivity type provided in the semiconductor substrate and extending from the principal surface in a first direction perpendicular to the principal surface;
• a drain region of the second conductivity type provided in the semiconductor substrate at a location remote from the source region;
• a trench dug from the principal surface and extending from the source region to the drain region in a second direction;
• a gate insulating film provided on a surface of the trench;
• a gate electrode filling the trench through the gate insulating film;
• a source electrode electrically connected to the source region;
• and
• a drain electrode electrically connected to the drain region,
• wherein the source region, the base region and the drain region respectively have impurity concentrations, each of which is uniform in both the first direction and the second direction;
• and
• wherein, when a voltage is applied to the gate electrode, a channel region is formed in a portion of the semiconductor substrate adjoining the trench so as to a channel width in a depth direction of the trench, and so as to allow a current to flow therein in a direction parallel to the principal surface.

A semiconductor device comprising:

• a semiconductor substrate having a principal surface and aback surface being an opposite surface of the principal surface;
• a first conductivity type base region extending in the semiconductor substrate from the principal surface in a first direction perpendicular to the principal surface;
• a second conductivity type source region extending in the base region from the principal surface in the first direction;
• a drift region provided at an opposite side of the base region with respect to the source region;
• a second conductivity type drain region extending in the semiconductor substrate from the principal surface in the first direction separately from the base region;
• a trench dug from the principal surface and penetrating the base region from the source region in a second direction parallel to the principal surface;
• a gate insulating film provided on a surface of the trench;
• a gate electrode provided on a surface of the gate insulating film;
• a source electrode electrically connected to the source region and the base region;
• and
• a drain electrode electrically connected to the drain region,
• wherein the drift region, the base region, the source region, and the drain region respectively have impurity concentrations, each of which is uniform in a depth direction of the semiconductor substrate.

A semiconductor device comprising:

• a semiconductor substrate having a principal surface and a back surface being an opposite surface of the principal surface;
• a first conductivity type base region extending in the semiconductor substrate from the principal surface in a first direction perpendicular to the principal surface;
• a second conductivity type source region extending in the base region from the principal surface in the first direction;
• a drift region provided at an opposite side of the base region with respect to the source region;
• a second conductivity type drain region extending in the semiconductor substrate from the principal surface in the first direction separately from the base region;
• a trench dug from the principal surface, extending in the semiconductor substrate in the first direction, and penetrating the base region from the source region in a second direction;
• a gate insulating film provided on a surface of the trench;
• a gate electrode provided on a surface of the gate insulating film;
• a source electrode electrically connected to the source region and the base region;
• and
• a drain electrode electrically connected to the drain region,
• wherein the drift region, the base region, the source region, and the drain region respectively have impurity concentrations, each of which is uniform in a depth direction of the semiconductor substrate.

A method for manufacturing a semiconductor device, comprising:

• preparing a first conductivity type semiconductor substrate having a principal surface and a back surface at an opposite side of the principal surface;
• forming a first trench in the semiconductor substrate, the first trench extending in the semiconductor substrate from the principal surface in a perpendicular direction with respect to the principal surface;
• forming a second conductivity type base region by filling up the first trench with a second conductivity type semiconductor;
• forming a second trench within the base region and a third trench in the semiconductor substrate at a location remote from the base region, each of the second trench and the third trench extending from the principal surface in the perpendicular direction;
• forming a first conductivity type source region by filling up the second trench with a first conductivity type semiconductor, and forming a first conductivity type drain region by filling up the third trench with the first conductivity type semiconductor;
• forming a fourth trench penetrating the base region from the source region, the fourth trench extending form the principal surface in the perpendicular direction;
• forming a gate insulating film in the fourth trench;
• forming a gate electrode on a surface of the gate insulating film;
• forming a source electrode electrically connected to the source region and the base region;
• and
• forming drain electrode electrically connected to the drain region.

A method for manufacturing a semiconductor device, comprising:

• preparing a semiconductor substrate having-a principal surface and a back surface being an opposite surface of the principal surface;
• forming a first trench at a first region of the semiconductor substrate and a second trench at a second region of the semiconductor substrate remote from the first region, each of the first trench and the second trench extending in the semiconductor substrate form the principal surface in a perpendicular direction with respect to the principal surface;
• covering the principal surface of the semiconductor substrate with a mask exposing the first trench from an opening of the mask while covering the second trench;
• forming a second conductivity type base region in the first trench by diffusing a second conductivity type impurity into the semiconductor substrate from the first trench, through the mask;
• removing the mask;
• forming a first conductivity type source region by filling up the first trench with a first conductivity type semiconductor, and forming a first conductivity type drain region by filling up the second trench with the first conductivity type semiconductor;
• forming a third trench in the semiconductor substrate to penetrate the base region from the source region and to extend from the principal surface in the perpendicular direction;
• forming a gate insulating film in the third trench;
• forming a gate electrode on the gate insulating film to fill up the third trench;
• forming a source electrode electrically connected to the source region and the base region;
• and
• forming a drain electrode electrically connected to the drain region.

A method for manufacturing a semiconductor device, comprising:

• preparing a semiconductor substrate having a principal surface and a back surface being an opposite surface of the principal surface;
• forming a first trench at a first region of the semiconductor substrate and a second trench at a second region of the semiconductor substrate remote from the first region, each of the first trench and the second trench extending in the semiconductor substrate form the principal surface in a perpendicular direction with respect to the principal surface;
• covering the principal surface of the semiconductor substrate with a mask exposing the second trench from an opening of the mask while covering the first trench;
• forming a first conductivity type drift region in the semiconductor substrate by diffusing a first conductivity type impurity into the semiconductor substrate from the second trench, through the mask;
• removing the mask;
• forming a first conductivity type source region by filling up the first trench with a first conductivity type semiconductor, and forming a first conductivity type drain region by filling up the second trench with the first conductivity type semiconductor;
• forming a third trench in the semiconductor substrate to penetrate the base region from the source region and to extend from the principal surface in the perpendicular direction;
• forming a gate insulating film in the third trench;
• forming a gate electrode on the gate insulating film to fill up the third trench;
• forming a source electrode electrically connected to the source region and the base region;
• and
• forming a drain electrode electrically connected to the drain region.

A method for manufacturing a semiconductor device, comprising:

• preparing a first conductivity type semiconductor substrate having a principal surface and a back surface at an opposite side of the principal surface;
• forming a first trench in the semiconductor substrate, the first trench extending in the semiconductor substrate from the principal surface in a perpendicular direction with respect to the principal surface;
• forming a drift formation film constituting a first conductivity type drift region, in the first trench such that the drift formation film covers an inner wall of the first trench and has a recess;
• forming a base formation film constituting a second conductivity type base region in the recess of the drift formation film such that the base formation film covers the drift region in the trench and has a recess;
• forming a source formation film constituting a first conductivity type source region such that the source formation film covers the base region in the trench;
• flattening the drift formation film, the base formation film, and the source formation film;
• forming a second trench in the semiconductor substrate, the second trench passing through the base region from the source region and extending from the principal surface in the perpendicular direction;
• forming a gate insulating film in the second trench;
• forming a gate electrode on a surface of the gate insulating film;
• forming a source electrode electrically connected to the source region and the base region;
• and forming drain electrode electrically connected to the drain region.

A method for manufacturing a semiconductor device, comprising:

• preparing a first conductivity type semiconductor substrate having a principal surface and a back surface at an opposite side of the principal surface;
• forming a first trench in the semiconductor substrate, the first trench extending in the semiconductor substrate from the principal surface in a perpendicular direction with respect to the principal surface;
• forming a drift formation film constituting a first conductivity type drift region, in the first trench such that the drift formation film covers an inner wall of the first trench and has a recess;
• forming a second conductivity type base region at a surface portion of the drift region by doping a second conductivity type impurity into the surface portion of the drift region in the trench;
• forming a source formation film constituting a first conductivity type source region such that the source formation film covers the base region in the trench;
• flattening the drift formation film and the source formation film;
• forming a second trench in the semiconductor substrate, the second trench passing through the base region from the source region base and extending from the principal surface in the perpendicular direction;
• forming a gate insulating film in the second trench;
• forming a gate electrode on a surface of the gate insulating film;
• forming a source electrode electrically connected to the source region and the base region;
• and
• forming drain electrode electrically connected to the drain region.

A method for manufacturing a semiconductor device, comprising:

• preparing a first conductivity type semiconductor substrate having a principal surface and a back surface at an opposite side of the principal surface;
• forming a first trench in the semiconductor substrate, the first trench extending in the semiconductor substrate from the principal surface in a perpendicular direction with respect to the principal surface;
• forming a drift region by doping a second conductivity type impurity into the semiconductor substrate from an inner wall of the first trench;
• forming a base region in the drift region by doping the second conductivity type impurity from the inner wall of the first trench;
• forming a source formation film constituting a first conductivity type source region such that the source formation film covers the base region in the trench;
• flattening the source formation film;
• forming a second trench in the semiconductor substrate, the second trench passing through the base region from the source region base and extending from the principal surface in the perpendicular direction;
• forming a gate insulating film in the second trench;
• forming a gate electrode on a surface of the gate insulating film;
• forming a source electrode electrically connected to the source region and the base region;
• and forming drain electrode electrically connected to the drain region.

A method for manufacturing a semiconductor device, comprising:

• preparing a first conductivity type semiconductor substrate having a principal surface and a back surface at an opposite side of the principal surface;
• forming a first trench in the semiconductor substrate, the first trench extending in the semiconductor substrate from the principal surface in a perpendicular direction with respect to the principal surface;
• forming a drift region by doping a second conductivity type impurity into the semiconductor substrate from an inner wall of the first trench;
• forming a base formation film constituting a second conductivity base region, the base formation film covering the drift region in the first trench and having a recess corresponding to the first trench;
• forming a source formation film constituting a first conductivity type source region such that the source formation film covers the base region in the trench;
• flattening the base formation film and the source formation film;
• forming a second trench in the semiconductor substrate, the second trench passing through the base region from the source region base and extending from the principal surface in the perpendicular direction;
• forming a gate insulating film in the second trench;
• forming a gate electrode on a surface of the gate insulating film;
• forming a source electrode electrically connected to the source region and the base region;
• and
• forming drain electrode electrically connected to the drain region.