Method for manufacturing an integrated power device on a semiconductor substrate and corresponding device

A power device being integrated on a semiconductor substrate and comprising:

• at least a trench being made in said semiconductor substrate, and having sidewalls and a bottom;
• a first insulating material coating layer extending along said sidewalls and said bottom of said at least one trench;
• a conductive gate structure being made inside said at least one trench;
• wherein conductive gate structure comprises a second conductive coating layer of a first conductive material extending along said sidewalls of said at least one trench and a conductive central region of a second conductive material being interconnected to said second conductive coating layer by means of a plurality of conductive bridges, the second conductive material having a different resistivity than said first conductive material.

A method for manufacturing a power device being integrated on a semiconductor substrate comprising:

• making, in said semiconductor substrate, at least a trench having sidewalls and a bottom;
• covering said sidewalls and said bottom of said at least one trench with a first insulating coating layer;
• making, inside said at least one trench, a conductive gate structure;
• wherein said step of making said gate structure comprises:
• covering said at least sidewalls with a second conductive coating layer of a first conductive material;
• making a conductive central region of a second conductive material having a different resistivity than said first conductive material;
• and
• making a plurality of conductive bridges between said second conductive coating layer and said conductive central region;
• and
• wherein making a plurality of conductive bridges comprises:
• making along said sidewalls of said at least one trench a plurality of contact areas spaced out by insulating elements, said insulating elements being interposed between said second conductive coating layer and said conductive central region;
• filling in the plurality of contact areas with said second conductive material in order to make said conductive bridges.

A power device being integrated on a semiconductor substrate and comprising:

• at least a trench being made in said semiconductor substrate, and having sidewalls and a bottom;
• a first insulating material coating layer extending along said sidewalls and said bottom of said at least one trench;
• a conductive gate structure being made inside said at least one trench;
• wherein said conductive gate structure comprises a second conductive coating layer of a first conductive material extending along said sidewalls of said at least one trench and a conductive central region of a second conductive material being interconnected to said second conductive coating layer by means of a plurality of conductive bridges, the second conductive material having a different resistivity than said first conductive material;
• and
• a plurality of contact areas along said sidewalls of said at least one trench and interposed between said second conductive coating layer and said conductive central region, said plurality of contact areas being separated by insulating elements, said plurality of contact areas being filled in with said second conductive material in order to make said conductive bridges.

A transistor, comprising:

• a region of semiconductor material;
• a first trench disposed in the region and having a first trench bottom and a first trench side wall;
• a first gate insulator disposed over the trench bottom and the trench side wall;
• a first gate electrode disposed over the gate insulator;
• a first intermediate insulator disposed over the gate electrode and having a first opening;
• and
• a gate conductor disposed over the intermediate insulator and contacting the gate electrode through the opening.

A semiconductor structure, comprising:

• a region of semiconductor material;
• a trench disposed in the region and having a trench bottom and a trench side wall;
• a first insulator disposed over the trench bottom and the trench side wall;
• a first conductor disposed over the first insulator;
• a second insulator disposed over the first conductor and having a first opening;
• and
• a second conductor disposed over the second insulator and contacting the first conductor through the opening.

An integrated circuit, comprising:

• a region of semiconductor material;
• and
• a transistor including:
• a trench disposed in the region and having a trench bottom and a trench side wall;
• a gate insulator disposed over the trench bottom and the trench side wall;
• a gate electrode disposed over the gate insulator;
• an intermediate insulator disposed over the gate electrode and having a first opening;
• and
• a gate conductor disposed over the intermediate insulator and contacting the gate electrode through the opening.

A system, comprising:

• a first integrated circuit including
• a semiconductor region;
• and
• a transistor including:
• a trench disposed in the region and having a trench bottom and a trench side wall;
• a gate insulator disposed over the trench bottom and the trench side wall;
• a gate electrode disposed over the gate insulator;
• an intermediate insulator disposed over the gate electrode and having a first opening;
• and
• a gate conductor disposed over the intermediate insulator and contacting the gate electrode through the opening;
• and
• a second integrated circuit coupled to the first integrated circuit.

A method, comprising:

• forming in a region of semiconductor material a trench having a trench bottom and a trench side wall;
• forming a gate insulator over the trench bottom and the trench side wall;
• forming a gate electrode over the gate insulator;
• forming an intermediate insulator over the gate electrode;
• forming an opening in the intermediate insulator to expose a portion of the gate electrode;
• and
• forming a gate conductor that is in contact with the exposed portion of the gate electrode.