Selective thermal atomic layer deposition
A selective thermal atomic layer deposition (ALD) process is disclosed. The process may comprise loading a substrate comprising a dielectric material, and a metal, into a reactor. The substrate may be reacted with a non-plasma based oxidant, thereby forming an oxidized metal surface on the metal. The substrate may be heated and exposed to a passivation agent that adsorbs more onto the oxidized metal than the dielectric material. Such exposure may form a passivation layer on the oxidized metal surface, and the substrate may be exposed to a silicon precursor that adsorbs more onto the dielectric material than the passivation layer, forming a chemi-adsorbed silicon-containing layer on the dielectric material. The substrate may be exposed to the non-plasma based oxidant, that simultaneously partially oxidizes the passivation layer, and oxidizes the chemi-adsorbed silicon-containing layer to form a silicon-containing dielectric film on the dielectric material.
1 . A selective thermal atomic layer deposition (ALD) process, comprising:
(a) loading a substrate comprising a dielectric material and a metal into a reactor;
(b) reacting the substrate with a non-plasma based oxidant, thereby forming an oxidized metal surface on the metal;
(c) heating the substrate to a temperature less than, or equal to, 150° C.;
(d) exposing the substrate to a passivation agent that preferentially adsorbs more onto the oxidized metal surface than the dielectric material, thereby forming a passivation layer on the oxidized metal surface;
(e) exposing the substrate to a silicon precursor that preferentially adsorbs more onto the dielectric material than the passivation layer, thereby forming a chemi-adsorbed silicon-containing layer on the dielectric material; and
(f) exposing the substrate to the non-plasma based oxidant and simultaneously (1) partially oxidizing the passivation layer, thereby forming a partially oxidized passivation layer on the oxidized metal surface, and (2) oxidizing the chemi-adsorbed silicon-containing layer, thereby forming a silicon-containing dielectric film on the dielectric material; and
repeating steps (e) through (f) until a thickness of the silicon-containing dielectric film formed on the dielectric material reaches the predetermined value;
wherein the non-plasma based oxidant is selected from the group consisting of hydrogen peroxide, oxygen, and ozone.
2 . The selective thermal ALD process according to claim 1 , wherein the dielectric material is selected from the group consisting of silicon oxide, carbon doped silicon oxide, silicon oxynitride, carbon doped oxynitride, silicon nitride, and metal oxide.
3 . The selective thermal ALD process according to claim 1 , wherein the metal is selected from the group consisting of cobalt, aluminum, copper, tantalum, ruthenium, molybdenum, tungsten, platinum, iridium, nickel, titanium, silver, gold, and combinations thereof.
4 . The selective thermal ALD process according to claim 1 , wherein step (b), the reacting the substrate with a non-plasma based oxidant, thereby forming an oxidized metal surface on the metal step, occurs at a temperature less than, or equal to, 500° C.
5 . The selective thermal ALD process according to claim 4 , wherein step (b), the reacting the substrate with a non-plasma based oxidant, thereby forming an oxidized metal surface on the metal step, occurs at a temperature less than, or equal to, 150° C.
6 . The selective thermal ALD process according to claim 1 , wherein the passivation agent is selected from the group consisting of methanethiol, ethanethiol, propanethiol, butanethiol, pentanethiol, hexanethiol, heptanethiol, octanethiol, nonanethiol, decanethiol, undecanethiol, dodecanethiol, tridecanethiol, tetradecanethiol, pentadecanethiol, hexadecanethiol, heptadecanethiol, octadecanethiol, nonadecanethiol, tetrahydro-2H-pyran-4-thiol, 2-Propene-1-thiol, tetrahydro-2H-pyran-4-thiol, thiophenol, 4-methyl-1-thiophenol, 3-methyl-1-thiophenol, 2-Methyl-1-thiophenol, and para-xylene-alpha-thiol.
7 . The selective thermal ALD process according to claim 1 , wherein the passivation agent is selected from the group consisting of di-tert-butyl disulfide, and di-heptane disulfide.
8 . The selective thermal ALD process according to claim 1 , wherein the passivation agent is selected from the group consisting of 1H,1H,2H,2H-perfluorodecanethiol, 2,2,2-trifluoroethanethiol, 4-methyl-6-trifluoromethyl-pyrimidine-2-thiol, 4-trifluoromethylbenzyl mercaptan, 4-(trifluoromethoxy)benzyl mercaptan, 4-fluorobenzyl mercaptan, 3,5-bis(trifluoromethyl)benzenethiol, 2-(Trifluoromethyl) benzenethiol, 4-trifluoromethyl-2,3,5,6- tetrafluorothiophenol, 3,5-difluorobenzyl mercaptan, 4-trifluoromethyl-2,3,5,6-tetrafluorothiophenol, and para-trifluoromethylbenzenethiol.
9 . The selective thermal ALD process according to claim 1 , wherein the passivation layer comprises a monolayer of the passivation agent chemi-adsorbed to the oxidized metal surface.
10 . The selective thermal ALD process according to claim 1 , wherein the metal oxide is zirconium oxide, hafnium oxide, silicon doped zirconium oxide, or silicon doped hafnium oxide.
11 . A selective thermal atomic layer deposition (ALD) process, comprising:
(g) loading a substrate comprising a dielectric material and metal having a native metal oxide surface into a reactor;
(h) heating the substrate to a temperature less than, or equal to, 150° C.;
(i) exposing the substrate to a passivation agent that preferentially adsorbs more onto the native metal oxide surface than the dielectric material, thereby forming a passivation layer on the native metal oxide surface;
(j) exposing the substrate to a silicon precursor that preferentially adsorbs more onto the dielectric material than the passivation layer on the native metal oxide surface, thereby forming a chemi-adsorbed silicon-containing layer on the dielectric material; and
(k) exposing the substrate to a non-plasma based oxidant that simultaneously (1) partially oxidizes the passivation layer on the native metal oxide surface, thereby forming a partially oxidized passivation layer on the native metal oxide surface, and (2) oxidizes the chemi-adsorbed silicon-containing layer on the dielectric material, thereby forming a silicon-containing dielectric film on the dielectric material; and
repeating steps (i) through (k) until a thickness of the silicon-containing dielectric film formed on the dielectric material reaches the predetermined value;
wherein the non-plasma based oxidant is selected from the group consisting of hydrogen peroxide, oxygen, and ozone.
12 . The selective thermal ALD process according to claim 11 , wherein the dielectric material is selected from the group consisting of silicon oxide, carbon doped silicon oxide, silicon oxynitride, carbon doped oxynitride, silicon nitride, and metal oxide.
13 . The selective thermal ALD process according to claim 11 , wherein the metal is selected from the group consisting of cobalt, aluminum, copper, tantalum, ruthenium, molybdenum, tungsten, platinum, iridium, nickel, titanium, silver, gold, and combinations thereof.
14 . The selective thermal ALD process according to claim 11 , wherein the passivation agent is selected from the group consisting of methanethiol, ethanethiol, propanethiol, butanethiol, pentanethiol, hexanethiol, heptanethiol, octanethiol, nonanethiol, decanethiol, undecanethiol, dodecanethiol, tridecanethiol, tetradecanethiol, pentadecanethiol, hexadecanethiol, heptadecanethiol, octadecanethiol, nonadecanethiol, tetrahydro-2H-pyran-4-thiol, 2-Propene-1-thiol, tetrahydro-2H-pyran-4-thiol, thiophenol, 4-methyl-1-thiophenol, 3-methyl-1-thiophenol, 2-Methyl-1-thiophenol, and para-xylene-alpha-thiol.
15 . The selective thermal ALD process according to claim 11 , wherein the passivation agent is selected from the group consisting of di-tert-butyl disulfide, and di-heptane disulfide.
16 . The selective thermal ALD process according to claim 11 , wherein the passivation agent is selected from the group consisting of 1H,1H,2H,2H-perfluorodecanethiol, 2,2,2-trifluoroethanethiol, 4-methyl-6-trifluoromethyl-pyrimidine-2-thiol, 4-trifluoromethylbenzyl mercaptan, 4-(trifluoromethoxy)benzyl mercaptan, 4-fluorobenzyl mercaptan, 3,5-bis(trifluoromethyl)benzenethiol, 2-(Trifluoromethyl)benzenethiol, 4-trifluoromethyl-2,3,5,6- tetrafluorothiophenol, 3,5-difluorobenzyl mercaptan, 4-trifluoromethyl-2,3,5,6-tetrafluorothiophenol, and para-trifluoromethylbenzenethiol.
17 . The selective thermal ALD process according to claim 11 , wherein the passivation layer comprises a monolayer of the passivation agent chemi-adsorbed to the native metal oxide surface.
18 . The selective thermal ALD process according to claim 17 , wherein the passivation layer further comprises a second layer of the passivation agent physi-adsorbed to the monolayer of the passivation agent chemi-adsorbed to the native metal oxide surface.
19 . The selective thermal ALD process according to claim 11 , wherein the silicon precursor is an organoaminomonsilane selected from the group consisting of di-iso-propylaminosilane, di-sec-butylaminosilane, bis(diethylamino)silane, bis(dimethylamino)silane, bis(ethylmethylamino)silane, bis(tert-butylamino)silane, di-iso-propylaminomethylsilane, di-sec-butylaminomethylsilane, dimethylaminodimethylsilane, dimethylaminotrimethylsilane, bis(dimethylamino)methylsilane, tetrakis(dimethylamino)silane, tris(dimethylamino)silane, diethylaminodimethylsilane, dimethylaminodimethylsilane, di-iso-propylaminodimethylsilane, piperidinodimethylsilane, 2,6-dimethylpiperidinodimethylsilane, di-sec-butylaminodimethylsilane, iso-propyl-sec-butylaminodimethylsilane, tert-butylaminodimethylsilane, Iso-propylaminodimethylsilane, tert-pentylaminodimethylaminosilane, dimethylaminomethylsilane, di-iso-propylaminomethylsilane, iso-propyl-sec-butylaminomethylsilane, 2,6-dimethylpiperidinomethylsilane, di-sec-butylaminomethylsilane, bis(dimethylamino)methylsilane, bis(diethylamino)methylsilane, bis(di-iso-propylamino)methylsilane, bis(iso-propyl-sec-butylamino)methylsilane, bis(2,6-dimethylpiperidino)methylsilane, bis(iso-propylamino)methylsilane, bis(tert- butylamino)methylsilane, bis(sec-butylamino)methylsilane, bis(tert-pentylamino)methylsilane, bis(cyclohexylamino)methylsilane, bis(iso-propylamino)dimethylsilane, bis(iso-butylamino)dimethylsilane, bis(sec-butylamino)dimethylsilane, bis(tert-butylamino)dimethylsilane, bis(tert-pentylamino)dimethylsilane, bis(cyclohexylamino)dimethylsilane, and combinations thereof.
20 . The selective thermal ALD process according to claim 12 , wherein the metal oxide is zirconium oxide, hafnium oxide, silicon doped zirconium oxide, or silicon doped hafnium oxide.