Back to results
US 9,287,371 B2Granted
Semiconductor device having localized charge balance structure and method
AssigneeSemiconductor Components Industries, LLC
InventorsPeter Moens, Ana Villamor, Piet Vanmeerbeek, Jaume Roig-Guitart, Filip Bogman
Life of this patent
Estimating the term…
Abstract
In one embodiment, a semiconductor substrate is provided having a localized superjunction structure extending from a major surface. A doped region is then formed adjacent the localized superjunction structure to create a charge imbalance therein. In one embodiment, the doped region can be an ion implanted region formed within the localized superjunction structure. In another embodiment, the doped region can be an epitaxial layer having a graded dopant profile adjoining the localized superjunction structure. The charge imbalance can improve, among other things, unclamped inductive switching (UIS) performance.
Claims16
A semiconductor device structure comprising:
- a substrate;
- a first semiconductor layer overlying the substrate and having a major surface spaced apart from the substrate;
- a localized superjunction structure within a portion of the first semiconductor layer and extending from the major surface into at least the first semiconductor layer, wherein the localized superjunction structure comprises:
- a trench extending from the major surface into at least the first semiconductor layer, wherein the trench has a sidewall surface,
- a second semiconductor layer of a first conductivity type overlying the sidewall surface of the trench, having a generally vertical orientation and adjoining the first semiconductor layer, and
- a third semiconductor layer of a second conductivity type disposed within the trench, wherein the third semiconductor layer is disposed adjacent to the second semiconductor layer;
- a control electrode adjacent the major surface and spaced apart from the localized superjunction structure;
- a body region adjacent the major surface, the body region being laterally interposed between the control electrode and the localized superjunction structure, wherein the localized superjunction structure adjoins a vertically oriented side surface of the body region and the first semiconductor layer adjoins a bottom surface of the body region, and wherein the body region extends downward from the major surface to a first depth;
- and
- a first doped region of the second conductivity type disposed extending from the major surface to a top surface of the third semiconductor layer, wherein the first doped region has a higher dopant concentration than the third semiconductor layer and is configured to provide a charge imbalance within the localized superjunction structure, and wherein:
- a first portion of the first doped region overlaps a top portion of the second semiconductor layer to laterally connect the body region to the third semiconductor layer, the first portion of the first doped region abutting the vertically oriented side surface of the body region,
- the first doped region extends vertically downward from the major surface to a second depth greater than the first depth, and
- the top portion of the second semiconductor layer separates a second portion of the first doped region from at least a portion of the vertically oriented side surface of the body region, the second portion of the first doped region being different from the first portion of the first doped region.
10 more elements
A semiconductor device structure comprising:
- a region of semiconductor material having a major surface;
- a trench extending from the major surface into the region of semiconductor material, wherein the trench has a sidewall surface;
- a first semiconductor layer of a first conductivity type overlying the sidewall surface of the trench;
- a second semiconductor layer of a second conductivity type disposed within the trench, wherein the second semiconductor layer is disposed adjacent to the first semiconductor layer and wherein the trench, the first semiconductor layer, and the second semiconductor layer are configured to provide a localized superjunction structure;
- a control electrode adjacent the major surface and spaced apart from the localized superjunction structure;
- a body region adjacent the major surface, the body region being laterally interposed between the control electrode and the localized superjunction structure, wherein the body region extends from the major surface into the region of semiconductor material to a first depth, and wherein the body region has a vertically oriented side surface adjoining the sidewall surface of the trench;
- and
- a first doped region of the second conductivity type disposed extending from the major surface to a to surface of the second semiconductor layer and to a second depth, wherein the first doped region has a higher dopant concentration than the second semiconductor layer, wherein the second depth is greater than the first depth, and wherein:
- a first portion of the first doped region overlaps a top portion of the first semiconductor layer and contacts the sidewall surface of the trench to laterally connect the body region to the second semiconductor layer, the first portion of the first doped region abutting the vertically oriented side surface of the body region,
- the top portion of the first semiconductor layer laterally separates a second portion of the first doped region from at least a portion of the vertically oriented side surface of the body region, the second portion of the first doped region being different from the first portion of the first doped region, and
- the first doped region is configured to provide a charge imbalance within the localized superjunction structure.
8 more elements
A semiconductor device comprising:
- a region of semiconductor material having a major surface;
- a trench extending from the major surface into the region of semiconductor material, wherein the trench has a sidewall surface;
- a superjunction structure disposed in the trench and comprising a first conductivity type region along the sidewall surface of the trench and having a generally vertical orientation, the superjunction structure further comprising a second conductivity type region adjacent to the first conductivity type region;
- a body region adjacent the major surface and the superjunction structure, the body region being configured to form a channel region, wherein the body region has a vertically oriented side surface adjoining the trench;
- a control electrode adjoining a portion of the body region;
- a source region adjacent the body region;
- and
- a first doped structure extending from the major surface to a top surface of the second conductivity type region and configured to create a charge imbalance within an upper portion of the superjunction structure, wherein the first doped structure has a dopant concentration higher than the second conductivity type region, and wherein:
- a first portion of the first doped structure overlaps a top portion of the first conductivity type region and contacts the sidewall surface of the trench to laterally connect the body region to the second conductivity type region, the first portion of the first doped structure abutting the vertically oriented side surface of the body region, and
- the top portion of the first conductivity type region laterally separates a second portion of the first doped structure from at least a portion of the vertically oriented side surface of the body region, the second portion of the first doped structure being different from the first portion of the first doped structure.
7 more elements
Dependencies are inferred from the claim text.