Semiconductor device including a resistor metallic layer and method of forming the same

1. A semiconductor device, comprising:

a source region and a drain region of a power switch on a substrate;

a resistor metallic layer over said source region and said drain region of said power switch, comprising:

a current sense resistor including a first current sense resistor metallic strip coupled between a first cross member and a second cross member, and

a first gain resistor including a first gain resistor metallic strip coupled to said first cross member; and

an amplifier over said substrate and coupled to said first gain resistor metallic strip.

2. The semiconductor device as recited in claim 1 wherein said first gain resistor metallic strip comprises a first serpentine metallic pattern.

3. The semiconductor device as recited in claim 1 further comprising a second gain resistor including a second gain resistor metallic strip coupled to said second cross member.

4. The semiconductor device as recited in claim 3 wherein said amplifier is coupled to said second gain resistor metallic strip.

5. The semiconductor device as recited in claim 3 wherein said first gain resistor metallic strip comprises a first serpentine metallic pattern and said second gain resistor metallic strip comprises a second serpentine metallic pattern.

6. The semiconductor device as recited in claim 1 wherein said amplifier is located at a periphery of said semiconductor device.

7. The semiconductor device as recited in claim 1 further comprising a source metallic strip between said source region and said resistor metallic layer, said first current sense resistor metallic strip being coupled to said source region through said source metallic strip.

8. The semiconductor device as recited in claim 7 further comprising an insulating layer between said source metallic strip and said resistor metallic layer, said first current sense resistor metallic strip being coupled to said source metallic strip by a via through said insulating layer.

9. The semiconductor device as recited in claim 1 wherein said resistor metallic layer includes a second current sense resistor metallic strip coupled between said first cross member and said second cross member.

10. The semiconductor device as recited in claim 9 wherein said second current sense resistor metallic strip contributes to a resistance value of said current sense resistor.

11. A semiconductor device, comprising:

a first source region and a first drain region of a first power switch on a substrate;

a second source region and a second drain region of a second power switch on said substrate;

a resistor metallic layer over said first source region and said first drain region of said first power switch and over said second source region and said second drain region of said second power switch, said resistor metallic layer comprising:

a first current sense resistor including a first current sense resistor metallic strip coupled between a first cross member and a second cross member,

a first gain resistor including a first gain resistor metallic strip coupled to said first cross member,

a second current sense resistor including a second current resistor metallic strip coupled between a third cross member and a fourth cross member, and

a second gain resistor including a second gain resistor metallic strip coupled to said third cross member;

a first amplifier over said substrate and coupled to said first gain resistor metallic strip; and

a second amplifier over said substrate and coupled to said second gain resistor metallic strip.

12. The semiconductor device as recited in claim 11 wherein said first gain resistor metallic strip comprises a first serpentine metallic pattern.

13. The semiconductor device as recited in claim 11 wherein said resistor metallic layer further comprises a third gain resistor including a third gain resistor metallic strip coupled to said second cross member.

14. The semiconductor device as recited in claim 13 wherein said first amplifier is coupled to said third gain resistor metallic strip.

15. The semiconductor device as recited in claim 13 wherein said first gain resistor metallic strip comprises a first serpentine metallic pattern and said third gain resistor metallic strip comprises a second serpentine metallic pattern.

16. The semiconductor device as recited in claim 11 wherein said first and second amplifiers are located at a periphery of said semiconductor device.

17. The semiconductor device as recited in claim 11 further comprising a first source metallic strip between said first source region and said resistor metallic layer and a second source metallic strip between said second source region and said resistor metallic layer, said first current sense resistor metallic strip being coupled to said first source region through said first source metallic strip and said second current sense resistor metallic strip being coupled to said second source region through said second source metallic strip.

18. The semiconductor device as recited in claim 17 further comprising an insulating layer between said first and second source metallic strips and said resistor metallic layer, said first current sense resistor metallic strip being coupled to said first source metallic strip by a via through said insulating layer and said second current sense resistor metallic strip being coupled to said second source metallic strip by another via through said insulating layer.

19. The semiconductor device as recited in claim 11 wherein said resistor metallic layer includes a third current sense resistor metallic strip coupled between said first cross member and said second cross member.

20. The semiconductor device as recited in claim 19 wherein said third current sense resistor metallic strip contributes to a resistance value of said first current sense resistor.