Lateral trench MISFET

A lateral trench MISFET comprising:

• a semiconductor layer of a first conductivity type;
• a trench formed in a surface layer of said semiconductor layer;
• a drain region of the first conductivity type formed at a bottom of said trench;
• a side wall insulation film formed on a side face of said trench;
• a well region of the first conductivity type formed in a part of the surface layer of said semiconductor layer separate from the trench, said well region being more heavily doped than said semiconductor layer;
• a base region of a second conductivity type formed in a part of a surface layer of said well region;
• a source region of the first conductivity type formed in a surface layer of said base region, such that said base region forms an extension portion that extends between said well region and said source region;
• a gate electrode overlying said extension portion;
• a gate insulation film provided between the gate electrode and said extension portion;
• a source electrode connected to both said source region and said base region;
• and
• a conductive material disposed in said trench.

A lateral trench MISFET comprising:

• a semiconductor layer of a first conductivity type;
• a trench formed in a surface layer of said semiconductor layer;
• a drain drift region of a second conductivity type formed at a portion of said semiconductor layer facing said trench;
• a drain region of the second conductivity type formed at a bottom of said trench, said drain region being more heavily doped than said drain drift region;
• a side wall insulation film formed on a side face of said trench;
• a base region of the first conductivity type formed in a portion of said semiconductor layer separate from the trench;
• a source region of the second conductivity type formed in a part of a surface layer of said base region, such that said base region forms an extension portion that extends between said drain drift region and said source region;
• a gate electrode overlying the extension portion;
• a gate insulation film provided between the gate electrode and said extension portion
• a source electrode connected to both said source region and said base region;
• and
• a conductive material disposed in said trench.

A lateral trench MISFET comprising:

• a semiconductor layer of a first conductivity type;
• a trench formed in a surface layer of said semiconductor layer;
• a drain region of the first conductivity type formed at a bottom of said trench;
• a side wall insulation film formed on a side face of said trench;
• a base region of a second conductivity type formed at least in a part of the surface layer of said semiconductor layer separate from said trench;
• a source region of the first conductivity type formed in a part of a surface layer of said base region, said base region including a trench facing portion between said semiconductor layer and said source region;
• a gate electrode opposed to and facing the trench portion of said base region;
• a gate insulation film provided between said gate electrode and said trench facing portion;
• a source electrode connected to both said source region and said base region;
• and
• a conductive material disposed in said trench.

A lateral trench MISFET comprising:

• a semiconductor layer of a first conductivity type;
• a trench formed in a surface layer of said semiconductor layer;
• a drain region of the first conductivity formed at a bottom of said trench;
• a side wall insulation film formed on a side face of said trench;
• a well region of the first conductivity type formed at least in a part of the surface layer of said semiconductor layer separate from the trench, said well region being more heavily doped than said semiconductor layer;
• a base region of a second conductivity type formed in a part of a surface layer of said well region;
• a source region of the first conductivity type formed in a part of a surface layer of said base region, said base region including a trench facing portion that extends between said well region and said source region;
• a gate electrode opposed to and facing the trench facing portion of said base region;
• a gate insulation film provided between said gate electrode and said trench facing portion;
• a source electrode connected to both said source region and said base region;
• and
• a conductive material disposed in said trench, said conductive material being from said gate electrode.

A lateral trench MISFET comprising:

• a semiconductor layer of a first conductivity type;
• a trench formed in a surface layer of said semiconductor layer;
• a drain drift region of a second conductivity type formed in a portion of said semiconductor layer facing said trench;
• a drain region of the second conductivity type formed at a bottom of said trench, said drain region being more heavily doped than said drain drift region;
• a side wall insulation film formed on a side face of said trench;
• a base region of the first conductivity type formed at least in a part of the surface layer of said semiconductor layer separate from said trench;
• a source region of the second conductivity type formed in a part of a surface layer of said base region, said base region including a trench facing portion between said drain drift region and said source region;
• a gate electrode opposed to and facing the trench facing portion of said base region;
• a gate insulation film provided between said gate electrode and said trench portion;
• a source electrode connected to both said source region and said base region;
• and
• a conductive material disposed in said trench, said conductive material being insulated from said gate electrode.