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US 8,492,772 B2Granted
Homoepitaxial growth of SiC on low off-axis SiC wafers
AssigneeNorstel AB
InventorsAlexandre Ellison, Christer Hallin, Björn Magnusson, Peder Bergman
Life of this patent
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Abstract
A wafer including a SiC substrate having a surface that is inclined relative to a (0001) basal plane at an angle higher than 0.1 degree but less than 1 degree, a SiC homoepitaxial device layer, and a SiC homoepitaxial boundary layer having a thickness up to 1 μm arranged between the substrate and the device layer. The boundary layer has been grown on the substrate under an atmosphere of lower supersaturation than when forming the device layer and at a C/Si ratio above 1.
Claims12
An SiC wafer produced according to a method comprising:
- growing SiC homoepitaxial layers on a surface of an SiC substrate, wherein the layers have a same polytype as the substrate, and wherein the surface is inclined relative to a (0001) basal plane at an angle higher than 0.1 degree but less than 1 degree;
- starting an homoepitaxial growth by forming a boundary layer with a thickness up to 1 μm;
- and
- forming a homoepitaxial device layer wherein the boundary layer is formed in an atmosphere of lower supersaturation than when forming the homoepitaxial device layer and at a C/Si ratio above 1, such that the homoepitaxial device layer has a density of surface defects that is less than 2 cm−2.
1 more element
A wafer, comprising:
- a SiC substrate having a surface that is inclined relative to a (0001) basal plane at an angle higher than 0.1 degree but less than 1 degree;
- a SiC homoepitaxial device layer;
- and
- a SiC homoepitaxial boundary layer having a thickness up to 1 μm arranged between the substrate and the device layer, wherein the boundary layer has been grown on the substrate under an atmosphere of lower supersaturation than when forming the device layer and at a C/Si ratio above 1, wherein the homoepitaxial device layer has a density of surface defects that is less than 2 cm−2.
1 more element
An SiC wafer, comprising:
- an Sic substrate;
- SiC homoepitaxial layers on a surface of the SiC substrate, wherein the layers have a same polytype as the substrate, and wherein the surface of the substrate is inclined relative to a (0001) basal plane at an angle higher than 0.1 degree but less than 1 degree;
- a boundary layer having a thickness up to 1 μm;
- and
- a homoepitaxial device layer having a density of surface defects that is less than 2 cm−2.
2 more elements
Dependencies are inferred from the claim text.