Well and punch through stopper formation using conformal doping

1. A method for doping fins, comprising:

depositing a first dopant layer over fins formed in a substrate;

recessing the first dopant layer down to a height on the fins to expose a top portion of the fins;

forming a dielectric layer over the top portion of the fins,

etching the dielectric layer and the first dopant layer in a first region to expose the substrate and the fins;

forming a second dopant layer over the fins and the substrate in a first region, the second dopant layer extending to the height on the fins in the first region; and

annealing to drive dopants into the fins from the first dopant layer in a second region and from the second dopant layer in the first region to concurrently form punch through stoppers in the fins and wells in the substrate.

2. The method as recited in claim 1 , wherein the dielectric layer is disposed between the first dopant layer and the substrate.

3. The method as recited in claim 1 , wherein etching the dielectric layer and the first dopant layer in the first region includes removing the dielectric layer and the first dopant layer in the first region.

4. The method as recited in claim 1 , wherein forming the second dopant layer in the first region includes:

conformally depositing the second dopant layer over the fins and the substrate in the first region; and

recessing the second dopant layer to the height on the fins in the first region.

5. The method as recited in claim 4 , wherein recessing the second dopant layer to the height includes:

depositing an organic dielectric layer on the fins; and

recessing the organic dielectric layer to the height to etch the second dopant layer to the height.

6. The method as recited in claim 5 , wherein the organic dielectric layer is spun on.

7. The method as recited in claim 1 , wherein depositing the first dopant layer includes:

depositing a doped silicate glass; and

recessing the doped silicate glass to a thickness on the fins associated with the punch through stoppers.

8. The method as recited in claim 1 , wherein forming the second dopant layer includes depositing a doped silicate glass.

9. The method as recited in claim 1 , further comprising conformally forming a cap layer over the second dopant layer.

10. The method as recited in claim 8 , further comprising recessing the cap layer and second dopant layer to the height.

11. The method as recited in claim 1 , wherein the first region includes one of an n-type field effect transistor (NFET) region or a p-type field effect transistor (PFET) region and the second region includes the other of the NFET region or the PFET region.

12. The method as recited in claim 1 , wherein the first dopant layer and the second dopant layer include different dopant conductivity types.

13. The method as recited in claim 1 , further comprising forming a field dielectric over the first and second dopant layers.

14. The method as recited in claim 12 , wherein the field dielectric is formed from a base of the fins to a top of the punch through stoppers.

15. The method as recited in claim 1 , wherein annealing to drive the dopants into the fins from the first dopant layer in the second region and from the second dopant layer in the first region to concurrently form the punch through stoppers in the fins and the wells in the substrate includes forming a first well in the first region below the first dopant layer and a second well in the second region below the second dopant layer.