Semiconductor device with termination structure for power MOSFET applications

A semiconductor device comprising:

• an active device region containing a plurality of active devices;
• and
• a termination structure that surrounds the active device region, wherein the termination structure includes a first conductive region that surrounds the active device region, an insulator region that surrounds the first conductive region, and a second conductive region that surrounds the first conductive region and the insulator region,
• wherein the active device region and termination structure are formed into a semiconductor material of a first conductivity type,
• wherein the first conductive region is electrically connected to a gate metal and the second conductive region is connected to a drain metal;
• and
• a Schottky contact formed below the termination structure.

A semiconductor device comprising:

• an active device region containing a plurality of active devices;
• and
• a termination structure that surrounds the active device region, wherein the termination structure includes a first conductive region that surrounds the active device region, an insulator region that surrounds the first conductive region, and a second conductive region that surrounds the first conductive region and the insulator region,
• wherein the active device region and termination structure are formed into a semiconductor material of a first conductivity type,
• wherein the first conductive region is electrically connected to a gate metal and the second conductive region is connected to a drain metal, wherein the first and second conductive regions and the insulating region are formed in a common trench that surrounds the active region, and wherein a dielectric material lining an upper portion of sidewalls of the common trench is a first thickness, and a dielectric material lining a lower portion of the sidewalls of the common trench is a second thickness, wherein the second thickness is greater than the first thickness.

A semiconductor device comprising:

• an active device region containing a plurality of active devices;
• and
• a termination structure that surrounds the active device region, wherein the termination structure includes a first conductive region that surrounds the active device region, an insulator region that surrounds the first conductive region, and a second conductive region that surrounds the first conductive region and the insulator region, wherein the termination structure further surrounds an electrostatic discharge feature,
• wherein the active device region and termination structure are formed into a semiconductor material of a first conductivity type,
• wherein the first conductive region is electrically connected to a gate metal and the second conductive region is connected to a drain metal.

A semiconductor device comprising:

• an active device region containing a plurality of active devices;
• and
• a termination structure that surrounds the active device region, wherein the termination structure includes a first conductive region that surrounds the active device region, an insulator region that surrounds the first conductive region, and a second conductive region that surrounds the first conductive region and the insulator region, wherein a Schottky contact is formed outside of the termination structure,
• wherein the active device region and termination structure are formed into a semiconductor material of a first conductivity type,
• wherein the first conductive region is electrically connected to a gate metal and the second conductive region is connected to a drain metal.

A method for forming a semiconductor device comprising:

• forming an active device region containing a plurality of active devices in a semiconductor material of a first conductivity type;
• forming a termination structure that surrounds the active device region in the semiconductor material of the first conductivity type, wherein the termination structure includes a first conductive region that surrounds the active device region, an insulator region that surrounds the first conductive region, and a second conductive region that surrounds the first conductive region and the insulator region, wherein forming the termination structure includes:
• forming a termination trench in the semiconductor material of the first conductivity type, wherein the termination trench surrounds the active device region;
• lining sidewalls and a bottom surface of the termination trench with a dielectric material;
• disposing a conductive material in the termination trench, wherein the disposed conductive material lines the dielectric material on the sidewalls and the bottom surface;
• removing the conductive material on the bottom surface of the termination trench, wherein the first conductive region includes a first portion of the conductive material that remains on a sidewall of the termination trench that is closest to the one or more active semiconductor devices, and wherein second conductive region includes a second portion of the conductive material remains on a sidewall of the termination trench furthest from the one or more active semiconductor devices, and wherein the first and second portions of conductive material are not in contact with each other;
• and
• filling the space between the first and second portions of the conductive material with a trench filling insulator material;
• forming an electrical connection between the first conductive region and a gate metal;
• and
• forming an electrical connection between the second conductive region and a drain metal.

A method for forming a semiconductor device comprising:

• forming an active device region containing a plurality of active devices in a semiconductor material of a first conductivity type;
• forming a termination structure that surrounds the active device region in the semiconductor material of the first conductivity type, wherein the termination structure includes a first conductive region that surrounds the active device region, an insulator region that surrounds the first conductive region, and a second conductive region that surrounds the first conductive region and the insulator region, wherein the termination structure further surrounds an electrostatic discharge feature;
• forming an electrical connection between the first conductive region and a gate metal;
• and
• forming an electrical connection between the second conductive region and a drain metal.

A method for forming a semiconductor device comprising:

• forming an active device region containing a plurality of active devices in a semiconductor material of a first conductivity type;
• forming a termination structure that surrounds the active device region in the semiconductor material of the first conductivity type, wherein the termination structure includes a first conductive region that surrounds the active device region, an insulator region that surrounds the first conductive region, and a second conductive region that surrounds the first conductive region and the insulator region;
• forming an electrical connection between the first conductive region and a gate metal;
• and
• forming an electrical connection between the second conductive region and a drain metal;
• and
• forming a Schottky contact outside of the termination structure.