Granted Patent B2

US 8,390,091 · App. 13/143,548 · Granted Mar 5, 2013

Abstract

Claims (44)

1. A monolithic semiconductor structure, including;

a stack of layers including:

a substrate;

a first layer made from a first semiconductor material; and

a second layer made from a second semiconductor material, said first layer being situated between the substrate and the second layer and at least one of said first semiconductor material and said second semiconductor material containing a III-nitride material;

said structure including a power transistor, including:

a body formed in said stack of layers;

a first power terminal at a side of said first layer facing said second layer;

a second power terminal at least partly formed in said substrate; and

a gate structure for controlling the propagation through said body of electric signals between said first power terminal and said second power terminal; and

said structure further including a Schottky diode, including:

an anode;

a cathode including said substrate; and

a Schottky barrier between said cathode and said anode, said Schottky barrier being situated between said substrate and an anode layer in the stack of layers.

2. A monolithic semiconductor structure as claimed in claim 1 , including a conducting path between the anode and said first power source.

3. A monolithic semiconductor structure as claimed in claim 1 , including a recess through the first layer and/or the second layer and wherein said cathode is at least partially formed by a part of said recess filled with a cathode semiconductor material.

4. A monolithic semiconductor structure as claimed in claim 3 , wherein said first semiconductor material is an epitaxial material and said recess is filled with an epitaxial regrowth material.

5. A monolithic semiconductor structure as claimed in claim 3 , wherein said recess extends from a substrate side of said first layer through the first layer and the second layer, and wherein said recess is filled with a cathode III-nitride material.

6. A monolithic semiconductor structure as claimed in claim 1 , wherein said cathode III-nitride material is doped GaN.

7. A monolithic semiconductor structure as claimed in claim 5 , wherein said cathode III-nitride material has a higher doping concentration in a part of the recess adjacent to the substrate side than in a part of the recess adjacent to the anode.

8. A monolithic semiconductor structure as claimed in claim 1 , including an insulating region between said Schottky diode and said body which electrically separates an aread in which said Schottky diode is situated from said body.

9. A monolithic semiconductor structure as claimed in claim 1 , wherein said substrate is Ohmic.

10. A monolithic semiconductor structure as claimed in claim 1 , wherein said field effect transistor is a hetero-structure field effect transistor and said body includes a hetero-junction structure between said first power terminal and said second power terminal, said hetero-junction structure including an interface at which said first layer and said second layer are in contact with each other and along which interface, when in operation, a two dimensional electron gas is formed.

11. A monolithic semiconductor structure as claimed in claim 1 , wherein said first semiconductor material has a different band-gap than said second semiconductor material.

12. A monolithic semiconductor structure as claimed in claim 1 , including at least one intermediate layer, such as a transition layer and/or a nucleation layer, between the first layer and the substrate.

13. A monolithic semiconductor structure as claimed in claim 1 , wherein said first semiconductor and/or said second semiconductor material are a III-nitride material selected from the group consisting of: III-nitride material, binary III-nitride material, ternary III-nitride material, quaternary III-nitride material, GaN, AlGaN, InGaN; AlInN.

14. A monolithic semiconductor structure as claimed in claim 1 , wherein said first semiconductor material is not intentionally doped GaN and/said second semiconductor material is a material containing AlGaN.

15. A monolithic semiconductor structure as claimed in claim 1 , wherein said first layer has a thickness of at least 5 micrometers, such as 6 micrometers.

16. A monolithic semiconductor structure as claimed in claim 1 , wherein said substrate semiconductor material includes one or more materials of the group consisting of: SiC, doped or undoped Si, epitaxial grown material, crystalline material, poly-crystalline material.

17. An integrated circuit including at least one monolithic semiconductor structure as claimed in claim 1 and additional electronic components connected to the monolithic semiconductor structure to form an electronic circuit.

18. A method for manufacturing a monolithic semiconductor structure, including:

providing a stack of layers including:

a substrate;

a first layer made from a first semiconductor material; and

a second layer made from a second semiconductor material, said first layer being situated between the substrate and the second layer and at least one of said first semiconductor material and said second semiconductor material containing a III-nitride material; and

providing a power transistor, including:

forming a body in said stack of layers;

forming a first power terminal at a side of said first layer facing said second layer;

forming a second power terminal in said substrate;

forming a gate structure for controlling the propagation through said body of electric signals between said first power terminal and said second power terminal; and

providing a vertical Schottky diode, including:

forming an anode;

forming a cathode including said substrate; and

forming a Schottky barrier between said cathode and said anode, said Schottky barrier being situated between said substrate and an anode layer in said stack of layers.

Assignments (31)