Passivation processes for use with metallization techniques
View Patent ↗A method for passivating a substrate, such as a semiconductor substrate, that is to be “metallized,” or on which a metal film or structure is to be formed, includes exposing regions of the substrate that are to be metallized to hydrogen radicals or nitrogen radicals. The regions of the substrate that are treated in this fashion are coated or “stuffed.” Passivation of this type may be effected with a plasma that includes a gas such as argon, nitrogen, helium, or hydrogen, or a mixture of any of the foregoing, which will remove oxygen molecules from the surface to which metal adhesion is desired. The metal may then be formed thereon. Hydrogen radicals may also be used to passivate the surface of a substrate, such as a semiconductor substrate, from spontaneous fluorine etching. Such passivation is, of course, effected in a substantially fluorine free environment.
1. A method for forming a metal feature on a semiconductor device structure, comprising:
removing oxidation from the semiconductor device structure with argon species; and
passivating an exposed surface of the semiconductor device structure with at least one of hydrogen radicals and nitrogen radicals.
2. The method of claim 1 , wherein passivating comprises coating or stuffing the exposed surface with at least one of the hydrogen radicals and the nitrogen radicals.
3. The method of claim 1 , further comprising:
introducing the semiconductor device structure into a plasma including argon species.
4. The method of claim 3 , wherein introducing comprises introducing the semiconductor device structure into the plasma, with the plasma further including at least one of the hydrogen radicals and the nitrogen radicals.
5. The method of claim 3 , wherein introducing comprises introducing the semiconductor device structure into the plasma with the plasma further including the hydrogen radicals and the nitrogen radicals.
6. The method of claim 1 , further comprising:
introducing the semiconductor device structure into a plasma including helium species.
7. The method of claim 6 , wherein introducing comprises introducing the semiconductor device structure into the plasma, with the plasma further including at least one of the hydrogen radicals and the nitrogen radicals.
8. The method of claim 6 , wherein introducing comprises introducing the semiconductor device structure into the plasma with the plasma further including the hydrogen radicals and the nitrogen radicals.
9. The method of claim 1 , wherein passivating comprises passivating a base layer upon which the metal feature is to be formed.
10. The method of claim 1 , further comprising: depositing metal over at least a portion of the exposed surface.
11. The method of claim 10 , wherein depositing metal comprises depositing refractory metal over at least a portion of the exposed surface.
12. The method of claim 11 , wherein depositing refractory metal comprises forming a plurality of nucleation centers consisting of the refractory metal.
13. The method of claim 11 , wherein depositing refractory metal comprises depositing a refractory metal selected from the group consisting of tungsten, molybdenum, tantalum, and titanium.
14. The method of claim 10 , further comprising:
depositing at least one base layer onto at least a portion of the exposed surface.
15. The method of claim 14 , wherein depositing metal comprises depositing metal onto at least a portion of the at least one base layer.
16. The method of claim 14 , wherein depositing the at least one base layer comprises depositing at least one material with greater adhesion to an underlying material than a material to be deposited thereover.
17. The method of claim 14 , wherein depositing the at least one base layer comprises depositing titanium.
18. The method of claim 17 , further comprising:
depositing another refractory material over the titanium.
19. The method of claim 14 , wherein depositing the at least one base layer comprises depositing a plurality of base layers.
20. The method of claim 19 , wherein depositing a plurality of base layers includes depositing titanium on at least a portion of the at least one exposed area and depositing titanium nitride on at least a portion of the titanium.
21. The method of claim 20 , further comprising:
depositing another refractory material over the titanium nitride.
22. A method for minimizing spontaneous fluorine etching of a substrate during deposition of a feature that includes metal, comprising passivating an exposed surface of the semiconductor device structure with hydrogen radicals.
23. The method of claim 22 , wherein passivating is effected in an environment that is substantially free of fluorine species.
24. The method of claim 22 , wherein passivating is effected with a plasma that is substantially free of fluorine species.
25. The method of claim 22 , further comprising:
exposing the exposed surface to a deposition reaction concurrently with or following the act of passivating.
26. The method of claim 25 , wherein, during exposing, fluorine species present in the deposition reaction react with the hydrogen species.