Damascene resistor and method for measuring the width of same

1. A linewidth measurement structure comprising:

an insulating layer;

a damascene polysilicon line formed in said insulating layer, said polysilicon line having a first polysilicon region having a first resistivity directly on top of a second polysilicon region having a second resistivity, said first resistivity different than said second resistivity, a bottom surface of said first polysilicon region in contact with and coextensive with a top surface of said second polysilicon region, a bottom surface of said second polysilicon region in direct physical contact with said insulating layer.

2. The structure of claim 1 , wherein wherein said second resistivity is greater than said first resistivity.

3. The structure of claim 2 , wherein said second polysilicon region has a dopant concentration of less than a dopant concentration of said first polysilicon region.

4. The structure of claim 1 , wherein said first polysilicon region is un-saturated.

5. The structure of claim 1 , wherein said first polysilicon region extends to a top surface of said polysilicon line.

6. The structure of claim 1 , wherein said polysilicon line further includes a third polysilicon region, said third polysilicon region extending between said first polysilicon region and a top surface of said polysilicon line, said third polysilicon region having dopant concentration of less than a dopant concentration of said first polysilicon region, a bottom surface of said third polysilicon region in contact with and coextensive with a top surface of said first polysilicon region.

7. The structure of claim 6 , wherein said third polysilicon region has a dopant concentration of zero.

8. The structure of claim 6 , wherein said second and third polysilicon regions independently have dopant concentrations of zero to less than said dopant concentration of said first region.

9. The structure of claim 6 , wherein said second and third polysilicon regions both have a dopant concentration of zero.

10. The structure of claim 1 , wherein said first polysilicon region is doped with a dopant selected from the group consisting of phosphorus, arsenic and boron.

11. The structure of claim 1 , further including:

an additional insulating layer formed on top of said first insulating and said first region of said polysilicon line; and

a first electrically conductive via in direct physical contact with a top surface of said first polysilicon region at a first end of said polysilicon line; and

a second electrically conductive via in direct physical contact with said top surface of said first polysilicon region at a second and opposite end of said polysilicon line.

12. The structure of claim 1 , wherein said second polysilicon region has a dopant concentration of zero.

13. The structure of claim 1 , wherein said first polysilicon region is doped to a concentration between about 1E19 atm/cm 3 and about 1E20 atm/cm 3 .

14. The structure of claim 1 , further including:

an additional damascene polysilicon line formed in said insulating layer, said additional polysilicon line having a third polysilicon region directly on top of a fourth polysilicon region, said third polysilicon region having said first resistivity and said fourth polysilicon region having said second resistivity, a bottom surface of said third polysilicon region in contact with and coextensive with a top surface of said second region, a bottom surface of said second region in direct physical contact with said insulating layer, a width of said polysilicon line greater than a width of said additional polysilicon line.

15. The structure of claim 14 , further including:

a first polysilicon pad, integrally formed with said polysilicon line and said additional polysilicon and adjoining a first end of said polysilicon line and a first end of said additional polysilicon line;

a second polysilicon pad integrally formed with said polysilicon line and adjoining a second end of said polysilicon line; and

a third polysilicon pad integrally formed with said additional polysilicon line and adjoining a second end of said additional polysilicon line.

16. structure of claim 1 , wherein said polysilicon line extends into said insulating layer a same distance along an entire length of said polysilicon line from a first end to an opposite second end and from a first side to an opposite second side.