Reducing line bending during metal fill process
Methods of mitigating line bending during feature fill include deposition of an amorphous layer and/or an inhibition treatment during fill.
1. A method comprising:
(a) providing a substrate having a plurality of features spaced apart, each feature having a feature opening width, wherein the width of at least some of the features narrows from the top of the feature to the bottom of the feature;
(b) depositing a conformal amorphous metal-based layer in the features;
(c) after depositing the conformal amorphous metal-based layer, depositing a bulk metal layer in the features; and
(d) prior to depositing the bulk metal layer, depositing a metal nucleation layer in the features, wherein the metal nucleation layer has a higher percentage of metal than in the amorphous metal-based layer.
2. The method of claim 1 , wherein the width of the bottom of each feature is between 0 nm and 90% of the width at the top of the feature.
3. The method of claim 1 , wherein the metal is selected from the group consisting of tungsten, ruthenium, molybdenum, and cobalt.
4. The method of claim 1 , further comprising annealing the conformal amorphous metal-based layer.
5. The method of claim 1 , wherein the features are spaced apart with a pitch of between about 10 nm and 60 nm between adjacent features.
6. The method of claim 1 , wherein (d) is performed prior to depositing the amorphous metal-based layer.
7. The method of claim 1 , wherein the metal-based layer comprises at least 50 atomic % metal.
8. The method of claim 1 , wherein the metal-based layer further comprises one or more of boron (B), nitrogen (N), carbon (C), silicon (Si), and germanium (Ge).
9. The method of claim 1 , wherein the conformal amorphous metal-based layer comprises a metal selected from tungsten (W), ruthenium (Ru), molybdenum (Mo), titanium (Ti), tantalum (Ta), and cobalt (Co) and wherein the metal-based layer is at least 5% (atomic) of an impurity selected from boron (B), nitrogen (N), carbon (C), silicon (Si), germanium (Ge), and combinations thereof.
10. The method of claim 9 , wherein the plurality of features are filled with a film selected from titanium nitride and tantalum nitride.
11. The method of claim 1 , further comprising after performing (c), repeating (b) and (c) one or more times to fill the feature.
12. A method comprising:
(a) providing a substrate having a plurality of features spaced apart, each feature having a feature opening width, wherein the width of the feature narrows from the top of the feature to the bottom of the feature;
(b) depositing a bulk metal layer in the features; and
(c) after depositing the bulk metal layer in the features, depositing an amorphous metal-based layer in the features, wherein the bulk metal layer is thicker than the amorphous metal-based layer and has a higher percentage of metal than in the amorphous metal-based layer.
13. The method of claim 12 , wherein the metal of metal-based layer is selected from the group consisting of tungsten, ruthenium, molybdenum, and cobalt.
14. The method of claim 12 , further comprising repeating (b) one or more times to fill the feature.
15. The method of claim 14 , further comprising repeating (c) one or more times to fill the feature.
16. The method of claim 15 , wherein the bulk films together form the main conductor of the filled feature.
17. The method of claim 12 , further comprising annealing the conformal amorphous metal-based layer.
18. The method of claim 12 , further comprising depositing a metal nucleation layer in the features.
19. The method of claim 12 , wherein the metal-based layer comprises at least 50% metal.
20. The method of claim 19 , wherein the metal-based layer further comprises one or more of boron (B), nitrogen (N), carbon (C), silicon (Si), and germanium (Ge).
21. A method comprising:
(a) providing a substrate having a plurality of features spaced apart, each feature having a feature opening width, wherein the width of the feature narrows from the top of the feature to the bottom of the feature;
(b) depositing a conformal, discontinuous film in the features including discontinuities in the features and/or or adsorbing metal species non-uniformly throughout each feature; and (c) after (b), depositing a bulk layer in the features.