Self-aligned field plate mesa FPM SiC schottky barrier diode
AssigneeHitachi Energy Ltd
InventorsAndrei Mihaila, Lars Knoll, Lukas Kranz
Life of this patent
Estimating the term…
Abstract
A power semiconductor device includes a wide-bandgap semiconductor layer having an active region and a termination region that laterally surrounds the active region. The wide-bandgap semiconductor layer has a first recess that is recessed from the first main side in the termination region and surrounds the active region and a second recess that is recessed from the first main side in the active region and is filled with an insulating material. A depth of the second recess is the same as a depth of the first recess. A field plate on the first main side of the wide-bandgap semiconductor layer exposes a first portion of the wide-bandgap semiconductor layer in the termination region.
Claims15
A power semiconductor device comprising:
- a wide-bandgap semiconductor layer having a first main side and a second main side opposite to the first main side, wherein the first main side and the second main side extend in a lateral direction and wherein the wide-bandgap semiconductor layer comprises an active region and a termination region that laterally surrounds the active region, wherein the wide-bandgap semiconductor layer has a first recess that is recessed from the first main side in the termination region and surrounds the active region and wherein the wide-bandgap semiconductor layer also has a second recess that is recessed from the first main side in the active region and is filled with an insulating material, a depth of the second recess being the same as a depth of the first recess;
- a field plate on the first main side of the wide-bandgap semiconductor layer over a first portion of the termination region, the field plate exposing the active region and a second portion of the wide-bandgap semiconductor layer in the termination region;
- and
- a dielectric layer interposed between the field plate and the wide-bandgap semiconductor layer to separate the field plate from the wide-bandgap semiconductor layer;
- wherein a sidewall of the first recess adjacent to the active region is laterally aligned with a circumferential edge of the field plate such that in an orthogonal projection onto a plane parallel to the first main side, an edge of the first recess defined by an upper end of the sidewall is within less than 1 nm from the circumferential edge of the field plate.
A power semiconductor device comprising:
- a wide-bandgap semiconductor layer having a first main side and a second main side opposite to the first main side, wherein the first main side and the second main side extend in a lateral direction and wherein the wide-bandgap semiconductor layer comprises an active region and a termination region that laterally surrounds the active region;
- a field plate on the first main side of the wide-bandgap semiconductor layer overlying a first portion of the termination region, the field plate exposing the active region and a second portion of the termination region, the second portion of the termination region spaced from the active region by the first portion of the termination region;
- a first recess that is recessed from the first main side in the termination region and surrounds the active region, wherein a sidewall of the first recess adjacent to the active region is laterally aligned with a circumferential edge of the field plate such that in an orthogonal projection onto a plane parallel to the first main side an edge of the first recess defined by an upper end of the sidewall is within less than 1 nm from the circumferential edge of the field plate;
- a plurality of second recesses that are recessed from the first main side in the active region and are filled with an insulating material, a depth of the plurality of second recesses being the same as a depth of the first recess;
- a dielectric layer interposed between the field plate and the wide-bandgap semiconductor layer to separate the field plate from the wide-bandgap semiconductor layer;
- a first electrode disposed at first main side and overlying the active region and the plurality of second recesses;
- and
- a second electrode disposed at the second main side.
Dependencies are inferred from the claim text.