Growth suppression deposition for CVD tungsten gap fill with thermal treatment
Embodiments of the disclosure provided herein include systems and methods for forming low resistivity tungsten features in a semiconductor device manufacturing scheme using growth suppression techniques. The system includes a processing chamber, a gas delivery system, and a system controller configured to expose at least one opening formed in a multi-tier structure of a substrate to a tungsten-containing precursor and a nucleation reducing agent. The tungsten-containing precursor and the nucleation reducing agent are alternated cyclically to form a nucleation layer within the at least one opening of the substrate. The system controller is further configured to expose the at least one opening of the substrate to a nitrogen-containing gas, a tungsten-containing gas, and a gapfill reducing agent gas to produce a non-uniform tungsten nitride passivation layer in the at least one opening.
1 . A substrate processing system, comprising:
a processing chamber;
a gas delivery system fluidly coupled to the processing chamber; and
a system controller configured to:
expose at least one opening formed in a multi-tier structure of a substrate, disposed in the processing chamber, to a tungsten-containing precursor at a precursor gas flow rate using the gas delivery system;
expose the at least one opening of the substrate, disposed in the processing chamber, to a nucleation reducing agent at a nucleation reducing agent flow rate using the gas delivery system, wherein the tungsten-containing precursor and the nucleation reducing agent are alternated cyclically to form a nucleation layer within the at least one opening of the substrate;
expose the at least one opening of the substrate, disposed in the processing chamber, to a nitrogen-containing gas, a tungsten-containing gas, and a gapfill reducing agent gas, using the gas delivery system, to produce a non-uniform tungsten nitride passivation layer in the at least one opening; and
expose the at least one opening of the substrate, disposed in the processing chamber, to the tungsten-containing gas, using the gas delivery system, to form a fill layer over the nucleation layer and the non-uniform tungsten nitride passivation layer within the at least one opening.
2 . The substrate processing system of claim 1 , wherein the nitrogen-containing gas and the tungsten-containing gas are co-flowed.
3 . The substrate processing system of claim 1 , wherein the nitrogen-containing gas and the gapfill reducing agent gas are co-flowed.
4 . The substrate processing system of claim 1 , wherein the nitrogen-containing gas, the tungsten-containing gas, and the gapfill reducing agent gas are co-flowed.
5 . The substrate processing system of claim 1 , wherein a flow of the nitrogen-containing gas is controlled by a first valve capable of producing pulse widths of 20 milliseconds.
6 . The substrate processing system of claim 5 , wherein the nitrogen-containing gas is co-flowed with the gapfill reducing agent gas before the tungsten-containing gas and the gapfill reducing agent gas are co-flowed.
7 . The substrate processing system of claim 6 , wherein the nitrogen-containing gas is co-flowed with the tungsten-containing gas before the tungsten-containing gas and the gapfill reducing agent gas are co-flowed.
8 . A substrate processing chamber, comprising:
a chamber lid assembly;
one or more sidewalls;
a chamber base;
a processing volume defined by the chamber lid assembly, the one or more sidewalls, and the chamber base, the processing volume configured to be coupled to a gas delivery system; and
a controller coupled to the substrate processing chamber and the gas delivery system and configured to:
expose at least one opening formed within a substrate disposed within the processing volume to a nitrogen-containing gas, a tungsten-containing gas, and a gapfill reducing agent gas to produce a non-uniform tungsten nitride passivation layer in the at least one opening, wherein the at least one opening comprises a lower portion and an upper portion, wherein the upper portion comprises a width smaller than a width of the lower portion; and
expose the at least one opening of the substrate disposed within the processing volume to the tungsten-containing gas to form a portion of a fill layer over the non-uniform tungsten nitride passivation layer within the at least one opening.
9 . The substrate processing chamber of claim 8 , wherein the nitrogen-containing gas and the tungsten-containing gas are co-flowed.
10 . The substrate processing chamber of claim 8 , wherein the nitrogen-containing gas and the gapfill reducing agent gas are co-flowed.
11 . The substrate processing chamber of claim 8 , wherein the nitrogen-containing gas, the tungsten-containing gas, and the gapfill reducing agent gas are co-flowed.
12 . The substrate processing chamber of claim 8 , wherein the at least one opening of the substrate is disposed within two or more tier layers, wherein a first tier layer interfaces a second tier layer at an interface, wherein a width of an opening within the second tier layer at the interface is narrower than a width of an opening within the first tier layer at the interface.
13 . The substrate processing chamber of claim 8 , wherein a flow of the nitrogen-containing gas is pulsed at a pulse width.
14 . The substrate processing chamber of claim 8 , wherein the tungsten-containing gas includes tungsten fluoride.
15 . The substrate processing chamber of claim 8 , wherein the nitrogen-containing gas is selected from the group consisting of NF 3 , NH 3 , N 2 H 4 , and combinations thereof.
16 . A method of forming a structure on a substrate, comprising:
forming a tungsten nucleation layer within at least one opening formed in a multi-tier structure of the substrate;
exposing the tungsten nucleation layer to a nitrogen-containing gas, a tungsten-containing gas, and a gapfill reducing agent gas to produce a non-uniform tungsten nitride passivation layer in the at least one opening; and
exposing the at least one opening to a tungsten-containing precursor gas to form a fill layer over the tungsten nucleation layer within the at least one opening.
17 . The method of claim 16 , wherein the nitrogen-containing gas and the tungsten-containing gas are co-flowed.
18 . The method of claim 16 , wherein the nitrogen-containing gas and the gapfill reducing agent gas are co-flowed.
19 . The method of claim 16 , wherein the nitrogen-containing gas, the tungsten-containing gas, and the gapfill reducing agent gas are co-flowed.
20 . The method of claim 19 , wherein exposing the at least one opening to the nitrogen-containing gas comprises pulsing the nitrogen-containing gas using a diaphragm valve capable of producing pulse widths of 20 milliseconds.