Methods of forming metal silicide layers and metal silicide layers formed therefrom
Methods for forming low resistivity metal silicide interconnects using one or a combination of a physical vapor deposition (PVD) process and an anneal process are described herein. In one embodiment, a method of forming a plurality of wire interconnects includes flowing a sputtering gas into a processing volume of a processing chamber, applying a power to a target disposed in the processing volume, forming a plasma in a region proximate to the sputtering surface of the target, and depositing the metal and silicon layer on the surface of the substrate. Herein, the first target comprises a metal silicon alloy and a sputtering surface thereof is angled with respect to a surface of the substrate at between about 10° and about 50°.
1. A method of processing a substrate, comprising:
forming a metal and silicon layer on a surface of the substrate having a plurality of openings formed therein, comprising:
flowing a sputtering gas into a first processing volume, wherein the first processing volume is a processing volume of a first processing chamber;
applying a power to a target disposed in the first processing volume, wherein the target comprises a metal-silicon alloy and a sputtering surface thereof is angled with respect to the surface of the substrate at between about 10° and about 50°;
forming a plasma in a region proximate to the sputtering surface of the target; and
depositing the metal and silicon layer on the surface of the substrate to fill the plurality of openings to at least a level of the surface; and
annealing the metal and silicon layer in a second processing volume, wherein the second processing volume is a processing volume of a second processing chamber, and wherein annealing the metal and silicon layer comprises:
pressurizing the second processing volume to a pressure of more than about 1 times atmospheric pressure using a pressurized gas delivered thereinto;
heating the substrate to an anneal temperature of not more than about 400° C.; and
maintaining the substrate at the anneal temperature for about 30 seconds or more.
2. The method of claim 1 , further comprising:
transferring the substrate from the first processing volume to the second processing volume using a transfer chamber that connects the first processing chamber to the second processing chamber.
3. The method of claim 1 , wherein the metal of the metal-silicon alloy is Ti, Ni, Pt, Co, or a combination thereof.
4. The method of claim 3 , wherein the metal-silicon alloy is an amorphous nickel-silicon alloy having an atomic composition of Ni x Si (1-x) , and wherein X is between about 0.4 and about 0.6.
5. The method of claim 4 , wherein the substrate comprises a dielectric layer having the plurality of openings formed therein, and wherein the annealed metal and silicon layer forms a plurality of NiSi interconnects in the plurality of openings.
6. The method of claim 5 , wherein a diameter of the first target is about 200 mm or less.
7. The method of claim 5 , further comprising depositing a passivation layer on the metal and silicon layer, the passivation layer comprising one of metal oxide, metal nitride, silicon oxide, silicon nitride, or a combination thereof.
8. The method of claim 5 , wherein the plurality of NiSi interconnects have a resistivity of about 200 μohm-cm or less.
9. A method of processing a substrate, comprising:
depositing an amorphous metal-silicon alloy layer on a surface of the substrate, the substrate comprising a dielectric layer having a plurality of openings formed therein, comprising:
flowing a sputtering gas into a first processing volume of a first processing chamber;
applying a power to a target disposed in the first processing volume, wherein the target comprises a metal-silicon alloy
forming a plasma in a region proximate to a sputtering surface of the target; and
depositing the amorphous metal-silicon alloy layer to fill the plurality of openings to at least a level of the surface of the dielectric layer; and
annealing the substrate, comprising:
positioning the substrate in a second processing volume of a second processing chamber,
pressurizing the second processing volume to a pressure between about 1 times and about 10 times atmospheric pressure using a pressurized gas delivered thereinto;
heating the substrate to an anneal temperature of not more than about 400° C.; and
maintaining the substrate at the anneal temperature for about 30 seconds or more.
10. The method of claim 9 , wherein the amorphous metal-silicon alloy has layer an atomic composition of M x Si (1-x) , wherein X is between about 0.4 and about 0.6.
11. The method of claim 9 , wherein annealing the substrate transforms the amorphous metal-silicon alloy layer to a crystalline metal-silicide layer having a substantially uniform stoichiometry.
12. The method of claim 11 , wherein the metal of the metal-silicon alloy layer comprises Ni.
13. The method of claim 11 , wherein the metal of the metal-silicide layer comprises Ti, Ni, Pt, Co, or a combination thereof.
14. The method of claim 9 , further comprising depositing a passivation layer on the amorphous metal-silicon alloy layer, the passivation layer comprising one of metal oxide, metal nitride, silicon oxide, silicon nitride, or a combination thereof.
15. A method of forming nickel-silicide interconnects, comprising:
depositing a nickel and silicon alloy layer on a surface of a substrate, the substrate comprising a dielectric layer having a plurality of openings formed therein, comprising:
flowing a sputtering gas into a first processing volume of a first processing chamber;
applying a power to a target disposed in the first processing volume, wherein the target comprises a metal-silicon alloy
forming a plasma in a region proximate to a sputtering surface of the target; and
depositing the nickel and silicon alloy layer to fill the plurality of openings to at least a level of the surface of the dielectric layer, wherein the nickel and silicon layer comprises an amorphous nickel-silicon alloy having an atomic composition of N x Si (1-x) , and wherein X is between about 0.4 and about 0.6; and
positioning the substrate in a second processing volume of a second processing chamber;
pressurizing the second processing volume to a pressure between about 1 times and about 10 times atmospheric pressure using a pressurized gas delivered thereinto;
heating the substrate to an anneal temperature of not more than about 400° C.; and
maintaining the substrate at the anneal temperature for about 30 seconds or more.
16. The method of claim 15 , wherein annealing the substrate forms a crystalline nickel-silicide layer having a substantially uniform stoichiometry.