Structure providing poly-resistor under shallow trench isolation and above high resistivity polysilicon layer
A structure provides a polysilicon resistor under a shallow trench isolation (STI). The structure includes the STI, a resistor in the form of a doped buried polysilicon layer under the STI, and a high resistivity (HR) polysilicon layer under the doped buried polysilicon layer. The structure also includes a pair of contacts operatively coupled in a spaced manner to the doped buried polysilicon layer. A related method is also disclosed.
1. A structure, comprising:
a shallow trench isolation (STI) including a lower surface;
a doped buried polysilicon layer at least partially under the lower surface of the STI;
a high resistivity (HR) polysilicon layer under the doped buried polysilicon layer; and
a pair of contacts operatively coupled in a spaced manner to the doped buried polysilicon layer.
2. The structure of claim 1 , wherein the HR polysilicon layer includes a noble dopant.
3. The structure of claim 1 , wherein the doped buried polysilicon layer under the STI includes a boron dopant.
4. The structure of claim 1 , further comprising an isolation ring bounding the doped buried polysilicon layer.
5. The structure of claim 4 , wherein the isolation ring is one of a trench isolation and a doped well.
6. The structure of claim 1 , further comprising a retarding implant region below the HR polysilicon layer, within the HR polysilicon layer, or both within and below the HR polysilicon layer.
7. The structure of claim 1 , wherein each contact includes a doped monocrystalline semiconductor material extending beside the STI, and each contact is operatively coupled to a lateral end of the doped buried polysilicon layer.
8. The structure of claim 7 , wherein each contact contacts an upper surface of the HR polysilicon layer.
9. The structure of claim 1 , wherein the doped buried polysilicon layer includes a pair of vertical portions extending vertically along lateral sides of the STI, wherein each contact includes a doped semiconductor material operatively coupled to an upper surface of a respective vertical portion of the doped buried polysilicon layer.
10. The structure of claim 1 , wherein each contact extends through the STI to an upper surface of the doped buried polysilicon layer, and each contact is in contact with the STI.
11. A structure, comprising:
a shallow trench isolation (STI) including a lower surface;
a resistor including a doped buried polysilicon layer at least partially under the lower surface of the STI;
a high resistivity (HR) polysilicon layer under the resistor; and
a pair of contacts operatively coupled in a spaced manner to the resistor,
wherein the HR polysilicon layer includes a noble dopant, and
wherein the doped buried polysilicon layer includes a boron dopant.
12. The structure of claim 11 , further comprising an isolation ring bounding the doped buried polysilicon layer.
13. The structure of claim 11 , wherein each contact includes a doped monocrystalline semiconductor material extending beside the STI, and each contact is operatively coupled to a lateral end of the doped buried polysilicon layer, wherein each contact contacts an upper surface of the HR polysilicon layer.
14. The structure of claim 11 , wherein the doped buried polysilicon layer includes a pair of vertical portions extending vertically along lateral sides of the STI, wherein each contact includes a doped semiconductor material operatively coupled to an upper surface of a respective vertical portion of the doped buried polysilicon layer.
15. The structure of claim 11 , wherein each contact extends through the STI to an upper surface of the doped buried polysilicon layer, and each contact is in contact with the STI.