Selective deposition of metal silicides
Embodiments of the disclosure relate to selective metal silicide deposition methods. In one embodiment, a substrate having a silicon containing surface is heated and the silicon containing surface is hydrogen terminated. The substrate is exposed to sequential cycles of a MoF 6 precursor and a Si 2 H 6 precursor which is followed by an additional Si 2 H 6 overdose exposure to selectively deposit a MoSi x material comprising MoSi 2 on the silicon containing surface of the substrate.
1. A substrate processing method, comprising:
heating a substrate having a silicon containing surface to a first temperature;
exposing the substrate to a plasma comprising hydrogen, wherein the plasma comprising hydrogen is formed from one or more precursors selected from the group consisting of NF 3 , NH 3 , and H;
exposing the substrate to a first dosage of a MoF 6 precursor;
exposing the substrate to a second dosage of a Si 2 H 6 precursor;
sequentially cycling the exposing the substrate to a first dosage and the exposing the substrate to a second dosage; and
after the sequential cycling, exposing the substrate to a third dosage of the Si 2 H 6 precursor.
2. The method of claim 1 , further comprising:
annealing the substrate after the exposing the substrate to a third dosage at a second temperature of between about 500° C. and about 550° C.
3. The method of claim 1 , wherein the first temperature is between about 100° C. and about 150° C.
4. The method of claim 1 , wherein the sequential cycling is performed less than 10 times.
5. The method of claim 4 , wherein the sequential cycling is performed 5 times.
6. The method of claim 1 , wherein a nitrogen purge process utilizing N 2 is performed during the sequential cycling.
7. The method of claim 1 , wherein the first dosage is performed for a duration of between about 10 ms and about 100 ms.
8. The method of claim 7 , wherein the first dosage comprises a MoF 6 flow rate of between about 1 MegaL and about 10 MegaL.
9. The method of claim 7 , wherein the second dosage is performed for a duration of between about 1 ms and about 50 ms.
10. The method of claim 9 , wherein the second dosage comprises a Si −2 H 6 flow rate of between about 1 MegaL and about 10 MegaL.
11. The method of claim 10 , wherein the third dosage comprises a Si 2 H 6 flow rate of between about 20 MegaL and about 50 MegaL.
12. The method of claim 11 , wherein the third dosage comprises between about 3 pulses and about 10 pulses of Si 2 H 6 .
13. The method of claim 1 , further comprising:
selectively depositing a MoSi x film on the silicon containing surface at a growth rate of about 1.2 nm per sequential cycle.
14. A substrate processing method, comprising:
positioning a substrate on a heater in a reaction chamber having chamber walls;
heating the substrate on the heater to a first temperature;
maintaining the chamber walls at a second temperature less than the first temperature;
exposing a silicon containing surface of the substrate to hydrogen, wherein the exposing a silicon containing surface of the substrate comprises exposing the silicon containing surface to either of a plasma formed from NF 3 /H 2 gases or a plasma formed from NF 3 /NH 3 gases;
exposing the substrate to a first dosage of a MoF 6 precursor;
exposing the substrate to a second dosage of a Si 2 H 6 precursor;
sequentially cycling the exposing the substrate to a first dosage and the exposing the substrate to a second dosage; and
after the sequential cycling, exposing the substrate to a third dosage of the Si 2 H 6 precursor.
15. The method of claim 14 , wherein the first temperature is between about 100° C. and about 150° C. and the second temperature is between about 65° C. and about 85° C.
16. The method of claim 14 , wherein the first dosage comprises a MoF 6 flow rate of between about 1 MegaL and about 10 MegaL, the second dosage comprises a Si 2 H 6 flow rate of between about 1 MegaL and about 10 MegaL, and the third dosage comprises a Si 2 H 6 flow rate of between about 20 MegaL and about 50 MegaL.
17. The method of claim 14 , further comprising:
selectively depositing a MoSi x film comprising MoSi 2 on the silicon containing surface at a growth rate of about 1.2 nm per sequential cycle.
18. A substrate processing method, comprising:
heating a substrate to a first temperature;
exposing a silicon containing surface of the substrate to a hydrogen containing plasma, the hydrogen containing plasma formed from one or more of an NF 3 precursor, and NH 3 precursor, and a precursor consisting of H;
exposing the substrate to a first dosage of a MoF6 precursor; exposing the substrate to a second dosage of a Si2H6 precursor; sequentially cycling the exposing the substrate to a first dosage and the exposing the substrate to a second dosage;
after the sequential cycling, exposing the substrate to a third dosage of the Si2H6 precursor; and
annealing the substrate after the exposing the substrate to a third dosage at a second temperature of between about 500° C. and about 550° C.