Recessed metal liner contact with copper fill
A method of fabricating a contact above a source or drain region of an integrated circuit includes depositing a first liner conformally in a bottom and along a sidewall of a trench formed above the source or drain region, depositing a second liner conformally over the first liner, and stripping the first liner and the second liner from a portion of the sidewall from an opening of the trench to a height above the bottom of the trench. The method also includes depositing a third liner conformally over the second liner on the bottom and to the height above the bottom of the trench and on the portion of the sidewall, and depositing a metal fill to fill the trench.
1. A method of fabricating a contact above a source or drain region of an integrated circuit, the method comprising:
depositing a first liner conformally in a bottom and along a sidewall of a trench formed above the source or drain region;
depositing a second liner conformally over the first liner;
stripping the first liner and the second liner from a portion of the sidewall from an opening of the trench to a height above the bottom of the trench;
depositing a third liner conformally over the second liner on the bottom and to the height above the bottom of the trench and on the portion of the sidewall; and
depositing a metal fill to fill the trench.
2. The method according to claim 1 , wherein the depositing the first liner includes depositing titanium.
3. The method according to claim 1 , wherein the depositing the first liner includes performing a physical vapor deposition or a chemical vapor deposition.
4. The method according to claim 1 , wherein the depositing the second liner includes depositing titanium nitride.
5. The method according to claim 1 , wherein the depositing the second liner includes performing chemical vapor deposition or atomic layer deposition.
6. The method according to claim 1 , further comprising depositing an organic planarization layer (OPL) after the depositing the first liner and the depositing the second liner prior to the stripping the first liner and the second liner.
7. The method according to claim 6 , further comprising performing a reactive ion etch process to recess the OPL to the height.
8. The method according to claim 7 , wherein the stripping the first layer and the second layer to the height includes performing a wet etch.
9. The method according to claim 1 , wherein the depositing the third liner includes depositing tantalum, tantalum nitride, ruthenium or a combination.
10. The method according to claim 1 , wherein the depositing the metal fill includes depositing copper.