High withstand-voltage lateral MOSFET with a trench and method of producing the same

A high withstand-voltage lateral MOSFET with a trench, comprising:

• a first conductive type semiconductor layer;
• a second conductive type source region;
• a second conductive type drain drift region, said second conductive type source region and said second conductive type drain drift region being formed in a portion of a surface layer of said first conductive type semiconductor layer at a distance from each other;
• a trench, filled with an insulating film, formed in a surface layer of said second conductive type drain drift region from a surface side thereof;
• a second conductive type drain region formed in the surface layer of said first conductive type semiconductor layer on a side opposite to said second conductive type source region with respect to said trench and partially overlapping said second conductive type drain drift region;
• a gate electrode, extending over said trench, provided on an exposed surface portion of said first conductive type semiconductor layer through a gate oxide film;
• a source electrode provided on a surface of said second conductive type source region;
• and
• a drain electrode provided on a surface of said second conductive type drain region.

A high withstand-voltage lateral MOSFET with a trench, comprising:

• a first conductive type semiconductor layer;
• a second conductive type source region;
• a second conductive type drain drift region, said second conductive type source region and said second conductive type drain drift region being formed in a portion of a surface layer of said first conductive type semiconductor layer at a distance from each other;
• a trench, filled with a semi-insulating film, formed in a surface layer of said second conductive type drain drift region from a surface side thereof;
• a second conductive type drain region formed in the surface layer of said first conductive type semiconductor layer on a side opposite to said second conductive type source region with respect to said trench and partially overlapping said second conductive type drain drift region;
• a gate electrode, extending over said trench, provided on an exposed surface portion of said first conductive type semiconductor layer through a gate oxide film;
• a source electrode provided on a surface of said second conductive type source region;
• and
• a drain electrode provided on a surface of said second conductive type drain region.

A high withstand-voltage lateral MOSFET with a trench, comprising:

• a first conductive type semiconductor layer;
• a first conductive type base region formed in a portion of a surface layer of said first conductive type semiconductor layer;
• a second conductive type source region formed in self-alignment in a portion of a surface layer of said first conductive type base region;
• a second conductive type drain drift region formed in a portion of the surface layer of said first conductive type semiconductor layer;
• a trench, filled with an insulating film, formed in a surface layer of said second conductive type drain drift region from a surface side thereof;
• a second conductive type drain region formed in the surface layer of said first conductive type semiconductor layer on a side opposite to said first conductive type base region with respect to said trench and partially overlapping said second conductive type drain drift region;
• a gate oxide film;
• a gate electrode, extending over said trench, provided on an exposed surface portion of said first conductive type base region through said gate oxide film;
• a source electrode provided on a surface of said second conductive type source region;
• and
• a drain electrode provided on a surface of said second conductive type drain region.

A high withstand-voltage lateral MOSFET with a trench, comprising:

• a first conductive type semiconductor layer;
• a first conductive type base region formed in a portion of a surface layer of said first conductive type semiconductor layer;
• a second conductive type source region formed in self-alignment in a portion of a surface layer of said first conductive type base region;
• a second conductive type drain drift region formed in a portion of the surface layer of said first conductive type semiconductor layer;
• a trench, filled with a semi-insulating film, formed in a surface layer of said second conductive type drain drift region from a surface side thereof;
• a second conductive type drain region formed in the surface layer of said first conductive type semiconductor layer on a side opposite to said first conductive type base region with respect to said trench and partially overlapping said second conductive type drain drift region;
• a gate oxide film;
• a gate electrode, extending over said trench, provided on an exposed surface portion of said first conductive type base region through said gate oxide film;
• a source electrode provided on a surface of said second conductive type source region;
• and
• a drain electrode provided on a surface of said second conductive type drain region.