Method of Manufacturing a Semiconductor Device with a Metal-Filled Groove in a Polysilicon Gate Electrode

A semiconductor device, comprising:

• a trench extending into a semiconductor substrate;
• a polysilicon gate electrode in the trench and which is insulated from the substrate;
• a body region of a first conductivity type in the substrate adjacent the trench;
• a source region of a second conductivity type opposite the first conductivity type adjacent the body region and the trench;
• a dielectric layer on the substrate;
• a gate metallization on the dielectric layer which covers part of the substrate;
• a source metallization on the dielectric layer and which is electrically connected to the source region, the source metallization being spaced apart from the gate metallization and covering a different part of the substrate than the gate metallization;
• and
• a metal-filled groove in the polysilicon gate electrode which is electrically connected to the gate metallization, the metal-filled groove extending along a length of the trench underneath at least part of the source metallization.

A semiconductor device, comprising:

• a semiconductor substrate;
• a body region of a first conductivity type in the substrate;
• a source region of a second conductivity type opposite the first conductivity type adjacent the body region;
• a drain region of the second conductivity type spaced apart from the source region;
• and
• a planar gate structure on the substrate, the planar gate structure comprising a polysilicon gate electrode insulated from the substrate and a metal-filled groove in the polysilicon gate electrode, the metal-filled groove extending along a length of the polysilicon gate electrode.