Methods for patterning substrates to adjust voltage properties

1 . A method of forming a structure on a substrate, the method comprising:

depositing a dipole dopant containing layer comprising a dipole dopant on a first region and a second region of a dielectric layer formed on the substrate;

depositing a hardmask over the dipole dopant containing layer deposited on the first and the second regions;

forming a patterned photoresist layer over the hardmask, wherein the patterned photoresist layer comprises a first portion that is positioned over the first region and an opening in the patterned photoresist layer that is positioned to expose a portion of the hardmask that is disposed over the second region of the substrate;

exposing the substrate to an etchant to etch the hardmask and dipole dopant containing layer within the second region and expose at least a portion of the dielectric layer within the second region;

removing the patterned photoresist layer from the substrate; and

annealing the substrate to diffuse the dipole dopant into a portion of the dielectric layer disposed in the first region.

2 . The method of claim 1 , wherein a dipole dopant concentration in the dipole dopant containing layer is about 1% to about 20%.

3 . The method of claim 1 , further comprising selecting a dipole dopant concentration in the dipole dopant containing layer based on a predetermined concentration of dopant to be diffused into the dielectric layer of the first region.

4 . The method of claim 3 , wherein the predetermined concentration of dopant to be diffused into the dielectric layer is determined based on a predetermined threshold voltage of the first region or a predetermined difference in threshold voltage of the first region relative to the second region.

5 . The method of claim 1 , depositing a dipole dopant containing layer comprises depositing a higher concentration of dipole dopant at a first surface disposed between the dipole dopant containing layer and the dielectric layer relative to a second surface of the dipole dopant containing layer, the second surface opposing the first surface.

6 . The method of claim 1 , further comprising, after annealing, etching the first and second region to expose the portion of the dielectric layer comprising dipole dopant in the first region and the dielectric layer in the second region using a first etchant and a second etchant, the first etchant comprising water, ammonium hydroxide, and hydrogen peroxide, the second etchant comprising hydrogen chloride and hydrogen peroxide.

7 . A method of forming a structure on a substrate, the method comprising:

depositing a dipole dopant containing layer comprising a dipole dopant on a first region and a second region of a dielectric layer formed on a substrate;

depositing a hardmask comprising an amorphous silicon-containing layer over the dipole dopant containing layer;

forming a patterned photoresist layer over the hardmask, wherein the patterned photoresist layer comprises a first portion that positioned over the first region and an opening in the patterned photoresist layer that is positioned to expose a portion of the hardmask that is disposed over the second region of the substrate;

exposing the patterned photoresist layer and substrate to an etchant to etch the hardmask and dipole dopant containing layer and expose at least a portion of the dielectric layer within the second region;

removing the patterned photoresist layer; and

annealing the substrate to diffuse the dipole dopant into a first portion of the dielectric layer disposed in the first region.

8 . The method of claim 7 , wherein the hardmask comprises a titanium nitride layer disposed below the amorphous silicon-containing layer.

9 . The method of claim 8 , wherein exposing the patterned photoresist layer and substrate to an etchant includes exposing the substrate to a first etchant and a second etchant, the first etchant comprising water, ammonium hydroxide, and hydrogen peroxide, and the second etchant comprising hydrogen chloride and hydrogen peroxide.

10 . The method of claim 7 , further comprising, before annealing, depositing a titanium nitride layer over the hardmask in the first region and over the dielectric layer in the second region; and

depositing an amorphous silicon-containing layer over the titanium nitride layer.

11 . The method of claim 10 , further comprising etching the annealed substrate to expose the first portion of the dielectric layer comprising the dipole dopant in the first region and a second portion of the dielectric layer in the second region.

12 . The method of claim 7 , wherein the hardmask comprises a titanium nitride layer below and above the amorphous silicon-containing layer.