Methods for filling a gap and related systems and devices
Methods and related systems for filling a gap feature comprised in a substrate are disclosed. The methods comprise a step of providing a substrate comprising one or more gap features into a reaction chamber. The one or more gap features comprise a proximal part comprising a proximal surface and a distal part comprising a distal surface. The methods further comprise a step of subjecting the substrate to a plasma treatment. Thus the proximal surface is inhibited while leaving the distal surface substantially unaffected. Then, the methods comprise a step of selectively depositing a metal- and nitrogen-containing material on the distal surface.
1. A method for filling a gap feature, the method comprising, in the given order:
a step of positioning a substrate on a substrate support in a reaction chamber, the substrate comprising a substrate surface comprising one or more gap features, the one or more gap features comprising a proximal part comprising a proximal surface and a distal part comprising a distal surface;
a step of subjecting the substrate to a plasma treatment, thereby selectively inhibiting the proximal surface with respect to the distal surface; and,
a step of selectively depositing a metal nitride on the distal surface,
wherein a metal of the metal nitride is a rare earth metal or a transition metal,
wherein the metal nitride is conductive, and
wherein the plasma treatment comprises exposing the substrate to a noble gas plasma.
2. The method according to claim 1 wherein a plurality of super-cycles are executed, a super cycle comprising the step of subjecting the substrate to the plasma treatment, and the step of selectively depositing the metal nitride on the distal surface.
3. The method according to claim 1 wherein the step of selectively depositing the metal nitride on the distal surface comprises a cyclical process, the cyclical process comprising a plurality of sub cycles, a sub cycle comprising, in the given order:
a step of exposing the substrate to a metal precursor, thereby forming chemisorbed metal precursor on the distal surface; and,
a step of exposing the substrate to a nitrogen reactant;
thereby allowing the nitrogen reactant to react with the chemisorbed metal precursor, thus forming a metal nitride on the distal surface.
4. The method according to claim 3 wherein the step of exposing the substrate to a metal precursor and the step of exposing the substrate to a nitrogen reactant are separated by an intra sub cycle purge.
5. The method according to claim 3 wherein subsequent sub-cycles are separated by an inter sub cycle purge.
6. The method according to claim 3 wherein the metal comprises the transition metal.
7. The method according to claim 6 wherein the transition metal comprises titanium.
8. The method according to claim 3 wherein the metal precursor comprises one or more alkylamine ligands.
9. The method according to claim 3 wherein the metal precursor has a general formula of M(NR 2 ) n , wherein M is a metal, R is a linear or branched C1 to C4 alkyl, and is an integer from at least 2 to at most 5.
10. The method according to claim 3 wherein the metal precursor comprises a metal halide.
11. The method according to claim 10 wherein the metal halide comprises a chloride.
12. The method according to claim 11 wherein the metal halide comprises TiCl 4 .
13. The method according to claim 3 wherein the nitrogen reactant comprises N 2 H 2 .
14. The method according to claim 1 wherein the metal is the rare earth metal.
15. The method according to claim 1 wherein the plasma treatment consists of exposing the substrate to the noble gas plasma.
16. The method according to claim 15 wherein the step of selectively depositing a metal nitride comprises providing a metal precursor comprising one or more ligands selected from NH 2 , NHR i , and NR i R ii , with at least one of R i and R ii being a C1 to C4 alkyl.
17. The method according to claim 1 wherein the substrate is maintained at a temperature of at least 50° C. to at most 300° C.
18. The method according to claim 1 wherein the plasma treatment comprises exposing the substrate to a nitrogen (N 2 ), argon, and helium plasma.
19. The method according to claim 1 wherein a concentration of constituents of the metal nitride varies from the distal surface to the proximal surface.