Power semiconductor device having fully depleted channel regions
A power semiconductor device includes a semiconductor body coupled to first and second load terminal structures, an active cell field in the body, and a plurality of first and second cells in the active cell field. Each cell is electrically connected to the first load terminal structure and to a drift region. Each first cell includes a mesa having a port region electrically connected to the first load terminal structure, and a channel region coupled to the drift region. Each second cell includes a mesa having a port region of the opposite conductivity type electrically connected to the first load terminal structure, and a channel region coupled to the drift region. Each mesa is spatially confined in a direction perpendicular to a direction of the load current within the respective mesa, by an insulation structure and has a total extension of less than 100 nm in the direction.
1. A power semiconductor device, comprising:
a semiconductor body coupled to a first load terminal structure and a second load terminal structure;
an active cell field implemented in the semiconductor body and configured to conduct a load current;
a plurality of first cells and a plurality of second cells provided in the active cell field, each being electrically connected to the first load terminal structure on one side and electrically connected to a drift region of the semiconductor body on another side, the drift region having a first conductivity type; and
one or more dummy cells provided in the active cell field, separating one of the first cells from one of the second cells;
wherein:
each first cell comprises a first mesa, the first mesa including: a first port region having the first conductivity type and being electrically connected to the first load terminal structure, a first channel region being coupled to the drift region, and a first control electrode that is configured to induce a current path for charge carriers of the first conductivity type within the first channel region;
each second cell comprises a second mesa, the second mesa including: a second port region having the second conductivity type and being electrically connected to the first load terminal structure, a second channel region being coupled to the drift region, and a second control electrode that is configured to induce a current path for charge carriers of the second conductivity type within the second channel region;
each of the one or more dummy cells comprises a third mesa, an insulation structure that directly adjoins the first load terminal structure, a semiconductor region in the third mesa that is coupled to the drift region and is insulated from the first load terminal structure by the insulation structure, and a third control electrode that is adjacent to and insulated from the semiconductor region; and
wherein the first and second control electrodes are independently controllable,
wherein the second control electrode is disconnected from the first load terminal structure,
wherein the third control electrode is connected to the first load terminal structure.
2. The power semiconductor device of claim 1 , wherein the one or more dummy cells immediately adjoin the one of the first cells at a first side and immediately adjoin the one of the second cells at a second side that is opposite from the first side.
3. The power semiconductor device of claim 1 , wherein the one or more dummy cells comprise a plurality of the dummy cells arranged successively next to one another and collectively between the one of the first cells and the one of the second cells.
4. The power semiconductor device of claim 1 , wherein the first cells are configured to fully deplete the first channel region of mobile charge carriers of the second conductivity type in a conducting state of the semiconductor device.