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US 2010/0140694 A1Published application
Semiconductor device having sub-surface trench charge compensation regions and method
AssigneeSemiconductor Components Industries, LLC
InventorsShanghui Larry Tu, Gordon M. Grivna
Life of this patent
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Abstract
In one embodiment, a semiconductor device is formed having sub-surface charge compensation regions in proximity to channel regions of the device. The charge compensation trenches comprise at least two opposite conductivity type semiconductor layers. A channel connecting region electrically couples the channel region to one of the at least two opposite conductivity type semiconductor layers.
Claims20
A semiconductor device comprising:
- a region of semiconductor material having a first major surface;
- a body region formed in the region of semiconductor material;
- a source region formed in the body region;
- a trench gate structure including a gate conductive layer separated from sidewalls of the trench gate structure by a gate dielectric layer, wherein the body region and source region are in proximity to the trench gate structure, and wherein the trench gate structure is configured to control a channel in the body the region when the semiconductor device is in operation;
- and
- a sub-surface trench compensation region formed in the region of semiconductor material adjacent a lower surface of the trench gate structure, wherein the sub-surface trench compensation region comprises a plurality of opposite conductivity type semiconductor layers.
3 more elements
A method for forming a semiconductor device comprising the steps of:
- providing a region of semiconductor material having a first major surface;
- forming a trench in the region of semiconductor material extending from the first major surface;
- forming a plurality of semiconductor layers within the trench including at least two opposite conductivity type semiconductor layers, and at least one buffer layer separating the at least two opposite conductivity type semiconductor layers to form a filled trench compensation region, wherein the buffer layer has a lower dopant concentration than the at least two opposite conductivity type semiconductor layers at formation;
- removing portions of the plurality of semiconductor layers so that remaining portions of the plurality of semiconductor layers are recessed below the first major surface to form a sub-surface filled trench compensation region in a lower portion of the trench;
- and
- forming a control electrode in an upper portion of the trench overlying the sub-surface filled trench compensation region;
- forming a body region within the region of semiconductor material, wherein the control electrode is configured to establish a channel in body region when the device is in operation;
- and
- forming a source region within the body region.
6 more elements
A semiconductor device comprising:
- a region of semiconductor material having a first major surface;
- a filled trench structure formed in the region of semiconductor material including:
- a charge compensating portion recessed below the first major surface, wherein the charge compensating portion includes a first layer of a first conductivity type and a second layer of a second conductivity type overlying the first layer;
- and
- a control portion formed overlying the charge compensating portion;
- a body region of the first conductivity type formed in the region of semiconductor material adjacent the filled trench structure, wherein the control portion is configured to create a channel within the body region when the device is in operation;
- and
- a first doped region of the second conductivity type formed in the region of semiconductor material and configured to electrically couple the channel to the charge compensating portion when the device is in operation.
5 more elements
Dependencies are inferred from the claim text.