Silicon carbide semiconductor device

Abstract

A silicon carbide (SiC) substrate is provided with an off-oriented {0001} surface whose off-axis direction is <11-20>. A trench is formed on the SiC to have a stripe structure extending toward a <11-20> direction. An SiC epitaxial layer is formed on an inside surface of the trench.

1. A silicon carbide semiconductor device comprising:
 a silicon carbide substrate having a top surface that is a {0001} plane having an off angle, wherein an off-axis direction of the off angle is <11-20>; and   a trench that is formed on the top surface of the silicon carbide substrate and has a stripe structure extending toward a <11-20> direction of the top surface of the silicon carbide substrate,   wherein a silicon carbide epitaxial layer is formed on an inside surface of the trench.   
     
     
       2. A silicon carbide semiconductor device comprising:
 a silicon carbide substrate having a top surface that is a {0001} plane having an off angle, wherein an off-axis direction of the off angle is <1-100>; and 
 a trench that is formed on the top surface of the silicon carbide substrate and has a stripe structure extending toward a <1-100> direction of the top surface of the silicon carbide substrate, 
 wherein a silicon carbide epitaxial layer is formed on an inside surface of the trench. 
 
     
     
       3. A silicon carbide semiconductor device comprising:
 a silicon carbide substrate having a top surface that is in a {0001} plane having an off angle, wherein an off-axis direction of the off angle is <11-20>; and 
 a trench that is formed on the top surface of the silicon carbide substrate, wherein the trench has a side wall having a surface that is in a {1-1001} plane. 
 wherein a silicon carbide epitaxial layer is formed on an inside surface of the trench. 
 
     
     
       4. A silicon carbide semiconductor device comprising:
 a silicon carbide substrate having a top surface that is in a {0001} plane having an off angle, wherein an off-axis direction of the off angle is <1-100>; and 
 a trench that is formed on the top surface of the silicon carbide substrate, wherein the trench has a side wall having a surface that is in a {11-20} plane, 
 wherein a silicon carbide epitaxial layer is formed on an inside surface of the trench. 
 
     
     
       5. A silicon carbide semiconductor device comprising:
 a silicon carbide substrate having a top surface that is in a plane having an off angle, wherein an off-axis direction of the off angle is a certain direction; and 
 a trench that is formed on the top surface of the silicon carbide substrate, wherein the trench has a planar structure, wherein each side of the planar structure is at an angle of 80 degrees or less with respect to the certain direction, 
 wherein a silicon carbide epitaxial layer is formed on an inside surface of the trench. 
 
     
     
       6. A silicon carbide semiconductor device comprising:
 a silicon carbide substrate having a top surface that is in a plane having an off angle, wherein an off-axis direction of the off angle is a certain direction; and 
 a trench that is formed on the top surface of the silicon carbide substrate, wherein the trench has a planar structure, wherein each side of the planar structure is at an angle of 75 degrees or less with respect to the certain direction, 
 wherein a silicon carbide epitaxial layer is formed on an inside surface of the trench. 
 
     
     
       7. A silicon carbide semiconductor device comprising:
 a silicon carbide substrate having a top surface that is in a {0001} plane having an off angle, wherein an off-axis direction of the off angle is <11-20>; and 
 a trench that is formed on the top surface of the silicon carbide substrate, wherein the trench has a side wall having a surface that is in a {11-20} plane and is not perpendicular to the off-axis direction, 
 wherein a silicon carbide epitaxial layer is formed on an inside surface of the trench. 
 
     
     
       8. A silicon carbide semiconductor device comprising:
 a silicon carbide substrate having a top surface that is a {0001} plane having an off angle, wherein an off-axis direction of the off angle is <1-100>; and  
 a trench that is formed on the top surface of the silicon carbide substrate, wherein the trench has a side wall having a surface that is in a {1-100} plane and is not perpendicular to the off-axis direction, 
 wherein a silicon carbide epitaxial layer is formed on an inside surface of the trench. 
 
     
     
       9. A silicon carbide semiconductor device comprising:
 a silicon carbide substrate that is a hexagonal crystal silicon carbide substrate having a top surface that is in a {11-20} plane; and 
 a trench that is formed on the top surface of the silicon carbide substrate, wherein the trench has a side wall that is inclined at an angle of one degree or more with respect to a {0001} plane in a virtual cross-sectional view that is perpendicular to the top surface of the silicon carbide substrate, 
 wherein a silicon carbide epitaxial layer is formed on an inside surface of the trench. 
 
     
     
       10. A silicon carbide semiconductor device comprising:
 a silicon carbide substrate being a hexagonal crystal silicon carbide substrate having a top surface that is in a {1-100} lane plane; and 
 a trench that is formed on the top surface of the silicon carbide substrate and has a side wall that is inclined at an angle of one degree or more with respect to a {0001} plane in a virtual cross-sectional view that is perpendicular to the top surface of the silicon carbide substrate, 
 wherein a silicon carbide epitaxial layer is formed on an inside surface of the trench.