Methods of filling a recessed feature on a substrate employing metal sequential infiltration synthesis processes
Methods for filling a recessed feature on a substrate employing metal sequential infiltration synthesis processes are disclosed. The disclosed methods include forming an organic layer within a recessed feature and introducing metal species into the organic layer to allow the formation of a metal seed layer. A bulk metal layer can subsequently be formed from the metal seed layer to fill the recessed feature.
1 . A method of filling a recessed feature on a substrate, the method comprising:
seating the substrate including the recessed feature within a reaction chamber, the recessed feature comprising a sidewall surface, a top surface, and a bottom surface, wherein the bottom surface comprises a first material and the sidewall surface comprises a second material different from the first material;
selectively forming an organic layer on the first material relative to the second material;
performing a metal sequential infiltration synthesis process to introduce metal species into the organic layer thereby forming a metal infiltrated layer;
removing organic components of the metal infiltrated layer thereby forming a metal seed layer on the bottom surface; and
forming a bulk metal layer directly on the metal seed layer, wherein the bulk metal layer fills the recessed feature.
2 . The method of claim 1 , wherein selectively forming the organic layer on the first material relative to the second material comprises;
selectively passivating a surface of the second material relative to a surface of the first material by introducing a passivating agent into the reaction chamber; and
depositing the organic layer on the surface of the first material.
3 . The method of claim 2 , wherein the organic layer is selectively formed with a selectivity greater than 50 percent.
4 . The method of claim 3 , wherein the passivating agent comprises an alkylaminosilane.
5 . The method of claim 4 , wherein the alkylaminosilane comprises at least one of allyltrimethylsilane (TMS-A), 1,1,1-Trimethoxy-N,N-dimethylsilanamine, chlorotrimethylsilane (TMS-Cl), N-(trimethylsilyl)imidazole (TMS-Im), octadecyltrichlorosilane (ODTCS), hexamethyldisilazane (HMDS), N-(trimethylsilyl)dimethylamine (TMSDMA), 1,1,1-Trimethoxy-N,N-dimethylsilanamine, trimethylchlorosilane, and combinations thereof.
6 . The method of claim 1 , further comprising thermally treating the organic layer in an ammonia (NH 3 ) ambient prior to performing the metal sequential infiltration synthesis process.
7 . The method of claim 1 , wherein performing the metal sequential infiltration synthesis process comprises introducing a metal precursor into the reaction chamber, the metal precursor containing the metal species.
8 . The method of claim 7 , wherein the metal species is selected from a group consisting of titanium, aluminum, niobium, tungsten, tantalum, cobalt, ruthenium, and molybdenum.
9 . The method of claim 7 , wherein performing the metal sequential infiltration synthesis process further comprises introducing a second precursor into the reaction chamber, the second precursor comprising hydrogen or ammonia.
10 . The method of claim 1 , wherein removing organic components of the metal infiltrated layer comprises a plasma etch process.
11 . The method of claim 1 , wherein forming the bulk metal layer directly on the metal seed layer comprises depositing the bulk metal layer by a cyclical deposition process.
12 . The method of claim 11 , wherein the bulk metal layer comprises titanium, aluminum, niobium, tungsten, tantalum, cobalt, ruthenium, and molybdenum.
13 . The method of claim 11 , wherein the bulk metal layer is the same as the metal seed layer.
14 . The method of claim 11 , wherein the bulk metal layer is different to the metal seed layer.
15 . A method of bottom-up gap filling of a recessed feature on a substrate, the method comprising:
seating the substrate including the recessed feature within a reaction chamber, the recessed feature including a bottom surface comprising a silicon germanium layer and a sidewall surface comprising a silicon layer;
passivating the sidewall surface comprising the silicon layer by introducing a passivating agent into the reaction chamber;
depositing an organic layer on the silicon germanium layer disposed at the bottom surface of the recessed feature;
performing at least one infiltration cycle of a sequential infiltration synthesis (SIS) sequence to introduce metal species into the organic layer thereby forming a metal infiltrated layer, wherein each infiltration cycle comprises introducing a metal precursor containing the metal species into the reaction chamber, the metal species selected from a group consisting of titanium, aluminum, niobium, tungsten, tantalum, cobalt, ruthenium, and molybdenum;
removing organic components of the metal infiltrated layer thereby forming a metal seed layer on the silicon germanium layer disposed at the bottom surface of the recessed feature; and
depositing a bulk metal layer directly on the metal seed layer employing a cyclical deposition process, wherein the bulk metal layer fills the recessed feature without the formation of a seam.
16 . The method of claim 15 , wherein the passivating agent comprises an alkylaminosilane selected from a group consisting of allyltrimethylsilane (TMS-A), 1,1,1-Trimethoxy-N,N-dimethylsilanamine, chlorotrimethylsilane (TMS-Cl), N-(trimethylsilyl)imidazole (TMS-Im), octadecyltrichlorosilane (ODTCS), hexamethyldisilazane (HMDS), N-(trimethylsilyl)dimethylamine (TMSDMA), 1,1,1-Trimethoxy-N,N-dimethylsilanamine, trimethylchlorosilane, and combinations thereof.
17 . The method of claim 16 , wherein the organic layer comprises a polyimide.
18 . The method of claim 17 , further comprising thermally annealing the organic layer in an ammonia (NH 3 ) ambient prior to performing at least one infiltration cycle of the sequential infiltration synthesis (SIS) sequence.
19 . The method of claim 18 , wherein the metal seed layer is a molybdenum seed layer, and the bulk metal layer is a bulk molybdenum layer.
20 . The method of claim 18 , wherein the metal seed layer is a titanium seed layer, and the bulk metal layer is a bulk molybdenum layer.