Composition for forming niobium-containing film and vapor deposition of niobium-containing film
阅读说明:本技术 形成含铌膜的组合物和含铌膜的气相沉积 (Composition for forming niobium-containing film and vapor deposition of niobium-containing film ) 是由 克莱蒙特·兰斯洛特-马特拉斯 李柱昊 卢沅泰 于 2018-06-05 设计创作,主要内容包括:披露了形成含铌膜的组合物、合成其的方法、以及使用该形成含铌膜的组合物通过原子层沉积工艺在一个或多个基板上形成含铌膜的方法。(Disclosed are a composition for forming a niobium-containing film, a method for synthesizing the same, and a method for forming a niobium-containing film on one or more substrates by an atomic layer deposition process using the composition for forming a niobium-containing film.)
1. A composition for forming a niobium-containing film comprising a precursor having the formula:
r, R therein 1、R 2And R 3Each independently is H, alkyl, or R' 3Si, wherein each R' is independently H or alkyl.
2. The niobium-containing film forming composition of claim 1, wherein the precursor has the formula Nb (═ NiPr) (R) 1,R 2,R 3-Pyr) 3。
3. The niobium-containing film forming composition of claim 2, wherein the precursor is selected from the group consisting of Nb (═ NiPr) (H, H-Pyr) 3、Nb(=NiPr)(Me,H,H-Pyr) 3、Nb(=NiPr)(Me,H,Me-Pyr) 3、Nb(=NiPr)(Me,Me,Me-Pyr) 3、Nb(=NiPr)(Et,H,Et-Pyr) 3、Nb(=NiPr)(nPr,H,nPr-Pyr) 3、Nb(=NiPr)(iPr,H,iPr-Pyr) 3、Nb(=NiPr)(tBu,H,tBu-Pyr) 3、Nb(=NiPr)(nBu,H,nBu-Pyr) 3、Nb(=NiPr)(sBu,H,sBu-Pyr) 3、Nb(=NiPr)(iBu,H,iBu-Pyr) 3、Nb(=NiPr)(tAmyl,H,tAmyl-Pyr) 3、Nb(=NiPr)(iPr,H,tBu-Pyr) 3、Nb(=NiPr)(iPr,H,Me-Pyr) 3、Nb(=NiPr)(iPr,H,Et-Pyr) 3、Nb(=NiPr)(TMS,H,TMS-Pyr) 3、Nb(=NiPr)(DMS,H,DMS-Pyr) 3And Nb (═ NiPr) (MMS, H, MMS-Pyr) 3。
4. The niobium film forming composition of claim 3, wherein the precursor is Nb (═ NiPr) (iPr, H, iPr-Pyr) 3。
5. The niobium-containing film forming composition of claim 1, wherein the precursor has the formula Nb (═ NtBu) (R) 1,R 2,R 3-Pyr) 3。
6. The niobium-containing film forming composition of claim 5, wherein the precursor is selected from the group consisting of Nb (═ NtBu) (H, H, H-Pyr) 3、Nb(=NtBu)(Me,H,H-Pyr) 3、Nb(=NtBu)(Me,H,Me-Pyr) 3、Nb(=NtBu)(Me,Me,Me-Pyr) 3、Nb(=NtBu)(Et,H,Et-Pyr) 3、Nb(=NtBu)(nPr,H,nPr-Pyr) 3、Nb(=NtBu)(iPr,H,iPr-Pyr) 3、Nb(=NtBu)(tBu,H,tBu-Pyr) 3、Nb(=NtBu)(nBu,H,nBu-Pyr) 3、Nb(=NtBu)(sBu,H,sBu-Pyr) 3、Nb(=NtBu)(iBu,H,iBu-Pyr) 3、Nb(=NtBu)(tAmyl,H,tAmyl-Pyr) 3、Nb(=NtBu)(iPr,H,tBu-Pyr) 3、Nb(=NtBu)(iPr,H,Me-Pyr) 3、Nb(=NtBu)(iPr,H,Et-Pyr) 3、Nb(=NtBu)(TMS,H,TMS-Pyr) 3、Nb(=NtBu)(DMS,H,DMS-Pyr) 3And Nb (═ NtBu) (MMS, H, MMS-Pyr) 3。
7. The niobium-containing film forming composition according to claim 6, wherein the precursor is Nb (═ NtBu) (iPr, H, iPr-Pyr) 3。
8. The niobium-containing film forming composition as claimed in claim 1, wherein the precursor has the formula Nb (═ NtAmyl) (R) 1,R 2,R 3-Pyr) 3。
9. The niobium-containing film forming composition of claim 8, wherein the precursor is selected from the group consisting of Nb (═ NtAmyl) (H, H, H-Pyr) 3、Nb(=NtAmyl)(Me,H,H-Pyr) 3、Nb(=NtAmyl)(Me,H,Me-Pyr) 3、Nb(=NtAmyl)(Me,Me,Me-Pyr) 3、Nb(=NtAmyl)(Et,H,Et-Pyr) 3、Nb(=NtAmyl)(nPr,H,nPr-Pyr) 3、Nb(=NtAmyl)(iPr,H,iPr-Pyr) 3、Nb(=NtAmyl)(tBu,H,tBu-Pyr) 3、Nb(=NtAmyl)(nBu,H,nBu-Pyr) 3、Nb(=NtAmyl)(sBu,H,sBu-Pyr) 3、Nb(=NtAmyl)(iBu,H,iBu-Pyr) 3、Nb(=NtAmyl)(tAmyl,H,tAmyl-Pyr) 3、Nb(=NtAmyl)(iPr,H,tBu-Pyr) 3、Nb(=NtAmyl)(iPr,H,Me-Pyr) 3、Nb(=NtAmyl)(iPr,H,Et-Pyr) 3、Nb(=NtAmyl)(TMS,H,TMS-Pyr) 3、Nb(=NtAmyl)(DMS,H,DMS-Pyr) 3And Nb (═ NtAmyl) (MMS, H, MMS-Pyr) 3。
10. The niobium-containing film forming composition as claimed in claim 9, wherein the precursor is Nb (═ NtAmyl) (iPr, H, iPr-Pyr) 3。
11. An atomic layer deposition process for forming a niobium-containing film, the process comprising introducing a vapor of the niobium-containing film forming composition of any one of claims 1-10 into a reactor having a substrate therein; and is
Depositing at least a portion of the precursor on the substrate.
12. The method of claim 11, further comprising introducing reactants into the reactor.
13. The method of claim 12, wherein the reactant is selected from the group consisting of: o is 2、O 3、H 2O、H 2O 2、NO、N 2O、NO 2Oxygen radicals thereof, and mixtures thereof.
14. The method according to claim 13, wherein the precursor for forming the niobium-containing film is Nb (═ NtBu) (iPr, H, iPr-Pyr) 3And the reactant is O 3。
15. The method of claim 14, wherein the substrate is a Ru layer.
Technical Field
Disclosed are a composition for forming a niobium-containing film, a method for synthesizing the same, and a method for forming a niobium-containing film on one or more substrates through a vapor deposition process using the composition for forming a niobium-containing film.
Background
Traditionally, zirconia (ZrO) 2) Thin films have been used as high-k materials for insulating layers in capacitor structures. More recently, it has been found that two ZrO layers are sandwiched 2Niobium oxide (Nb) between dielectric layers 2O 5) The thin film contributes to remarkably reducing leakage current and stabilizing ZrO 2Cubic/tetragonal phase of (a). ZrO thus obtained 2/Nb 2O 5/ZrO 2The stack provides a higher k value in the metal-insulator-metal (MIM) capacitor of today's Dynamic Random Access Memory (DRAM). (Alumina, J.Vac.Sci.Technol A [ journal of vacuum science and technology A ]]4(6),1986 and Microelectronic Engineering]86(2009)1789-1795)。
Metal nitrides (e.g. niobium nitride (NbN)
xWhere x is about 1)) films have been used in some niche-type applications, such as photon detectors at very low T (4K), when they become superconductors. Romestain et al, New Journal of Physics]
Gust et al disclose the synthesis, structure, and properties of iminoniobium and iminotantalum complexes with pyrazole ligands and their potential use for tantalum nitride film growth by CVD. Polyhedron 20(2001) 805-813. However, one of ordinary skill in the art will recognize that not all CVD precursors are suitable for use in ALD processes. See, e.g., Gordon et al: https:// www.scribd.com/document/310950017/ALD-an-Enabler-for-Nanoscience-and-Nanotechnology-Gordon-Harvard-reviewed-Amide-Compounds.
There remains a need to develop novel, liquid or low melting (<50 ℃), highly thermally stable niobium-containing precursor molecules suitable for atomic layer deposition of Nb-containing films, whether insulating or conductive.
Notation and nomenclature
Certain abbreviations, symbols, and terms are used throughout the following description and claims, and include:
the indefinite article "a" or "an", as used herein, means one or more than one.
As used herein, the term "about" or "about" means ± 10% of the stated value.
Any and all ranges described herein include their endpoints (i.e., x-1 to 4 or x in the range from 1 to 4 includes x-1, x-4 and x any number therebetween), regardless of whether the term "inclusive" is used.
Standard abbreviations for the elements of the periodic table of elements are used herein. It is understood that elements may be referred to by these abbreviations (e.g., Nb refers to niobium, N refers to nitrogen, C refers to carbon, etc.).
As used herein, the term "independently" when used in the context of describing R groups should be understood to mean that the subject R groups are selected not only independently with respect to other R groups bearing the same or different subscripts or superscripts, but also independently with respect to any additional species of the same R group. For example, in the formula MR 1 x(NR 2R 3) (4-x)Wherein x is 2 or 3, two or three R 1The radicals may, but need not, be identical to one another or to R 2Or with R 3The same applies.
As used herein, the term "alkyl" refers to a saturated functional group containing only carbon and hydrogen atoms. In addition, the term "alkyl" refers to a straight, branched, or cyclic alkyl group. Examples of straight chain alkyl groups include, but are not limited to, methyl, ethyl, propyl, butyl, and the like. Examples of branched alkyl groups include, but are not limited to, t-butyl. Examples of cycloalkyl groups include, but are not limited to, cyclopropyl, cyclopentyl, cyclohexyl, and the like.
As used herein, the abbreviation "Me" refers to methyl; the abbreviation "Et" means ethyl; the abbreviation "Pr" means propyl; the abbreviation "nPr" means "n" or linear propyl; the abbreviation "iPr" refers to isopropyl; the abbreviation "Bu" means butyl; the abbreviation "nBu" means "n" or straight-chain butyl; the abbreviation "tBu" refers to tert-butyl, also known as 1, 1-dimethylethyl; the abbreviation "sBu" refers to sec-butyl, also known as 1-methylpropyl; the abbreviation "iBu" refers to isobutyl, also known as 2-methylpropyl; the abbreviation "amyl" refers to pentyl (amyl) or pentyl (amyl group); the abbreviation "tAmyl" refers to tert-amyl, also known as 1, 1-dimethylpropyl.
As used herein, the abbreviation "TMS" refers to trimethylsilyl (Me) 3Si-); the abbreviation "DMS" means dimethylsilyl (Me) 2HSi-); the abbreviation "MMS" means monomethylsilyl (MeH) 2Si-); the abbreviation "py" refers to pyridine; and abbreviation R 1,R 2,R 3Pyr means having the following structureA structural pyrazolyl ligand:
note that the deposited film or layer (e.g., niobium oxide or niobium nitride) may be used throughout the specification and claims without reference to its proper stoichiometry (e.g., NbO, Nb) 2O 5) The case (2) is listed. These layers may also contain hydrogen, typically from 0 at% to 15 at%. However, any film compositions given ignore their H content, as not routinely measured, unless explicitly indicated otherwise.
Disclosure of Invention
Disclosed are compositions for forming niobium-containing films comprising precursors having the formula:
r, R therein 1、R 2And R 3Each independently is H, alkyl, or R' 3Si, wherein each R' is independently H or alkyl. The disclosed niobium-containing film-forming compositions may include one or more of the following aspects:
·R、R 1、R 2and R 3Each independently selected from H, Me, Et, nPr, iPr, tBu, sBu, iBu, nBu, tAmyl, SiMe 3、SiMe 2H. Or SiH 2Me;
Each R is iPr, tBu, or tAmyl;
each R 2Is H or Me;
·R、R 1、R 2and R 3tBu, H and H, respectively;
·R、R 1、R 2and R 3tBu, Me, H and H, respectively;
·R、R 1、R 2and R 3tBu, Me, H and Me, respectively;
·R、R 1、R 2and R 3tBu, Me and Me, respectively;
·R、R 1、R 2and R 3tBu, Et, H and Et, respectively;
·R、R 1、R 2and R 3tBu, nPr, H and nPr, respectively;
·R、R 1、R 2and R 3tBu, iPr, H and iPr, respectively;
·R、R 1、R 2and R 3tBu, H and tBu, respectively;
·R、R 1、R 2and R 3tBu, tAmyl, H and tAmyl, respectively;
·R、R 1、R 2and R 3tBu, iPr, H and tBu, respectively;
·R、R 1、R 2and R 3tBu, iPr, H and Me, respectively;
·R、R 1、R 2and R 3tBu, iPr, H and Et, respectively;
·R、R 1、R 2and R 3Are tBu and SiMe respectively 3H and SiMe 3;
·R、R 1、R 2And R 3Are tBu and SiHMe respectively 2H and SiHMe 2;
·R、R 1、R 2And R 3Are tBu, SiH respectively 2Me, H and SiH 2Me;
·R、R 1、R 2And R 3tAmyl, H and H, respectively;
·R、R 1、R 2and R 3tAmyl, Me, H and H, respectively;
·R、R 1、R 2and R 3tAmyl, Me, H and Me, respectively;
·R、R 1、R 2and R 3tAmyl, Me and Me, respectively;
·R、R 1、R 2and R 3tAmyl, Et, H and Et, respectively;
·R、R 1、R 2and R 3Are respectivelytAmyl, nPr, H, and nPr;
·R、R 1、R 2and R 3tAmyl, iPr, H and iPr, respectively;
·R、R 1、R 2and R 3tAmyl, tBu, H and tBu, respectively;
·R、R 1、R 2and R 3tAmyl, H and tAmyl, respectively;
·R、R 1、R 2and R 3tAmyl, iPr, H and tBu, respectively;
·R、R 1、R 2and R 3tAmyl, iPr, H, and Me, respectively;
·R、R 1、R 2and R 3tAmyl, iPr, H and Et, respectively;
·R、R 1、R 2and R 3Respectively being tAmyl and SiMe 3H and SiMe 3;
·R、R 1、R 2And R 3Respectively is tAmyl and SiHMe 2H and SiHMe 2;
·R、R 1、R 2And R 3Respectively being tAmyl, SiH 2Me, H and SiH 2Me;
·R、R 1、R 2And R 3iPr, H and H, respectively;
·R、R 1、R 2and R 3iPr, Me, H and H, respectively;
·R、R 1、R 2and R 3iPr, Me, H and Me, respectively;
·R、R 1、R 2and R 3iPr, Me and Me, respectively;
·R、R 1、R 2and R 3iPr, Et, H, and Et, respectively;
·R、R 1、R 2and R 3iPr, nPr, H, and nPr, respectively;
·R、R 1、R 2and R 3iPr, H, and iPr, respectively;
·R、R 1、R 2and R 3iPr, tBu, H and tBu, respectively;
·R、R 1、R 2and R 3iPr, tAmyl, H and tAmyl, respectively;
·R、R 1、R 2and R 3iPr, H and tBu, respectively;
·R、R 1、R 2and R 3iPr, H, and Me, respectively;
·R、R 1、R 2and R 3iPr, H, and Et, respectively;
·R、R 1、R 2and R 3Respectively iPr and SiMe 3H and SiMe 3;
·R、R 1、R 2And R 3Respectively iPr and SiHMe 2H and SiHMe 2;
·R、R 1、R 2And R 3Are iPr and SiH respectively 2Me, H and SiH 2Me;
The precursor has the formula Nb (═ NiPr) (H, H, H-Pyr) 3;
The precursor has the formula Nb (═ NiPr) (Me, H, H-Pyr) 3;
The precursor has the formula Nb (═ NiPr) (Me, H, Me-Pyr) 3;
The precursor has the formula Nb (═ NiPr) (Me, Me, Me-Pyr) 3;
The precursor has the formula Nb (═ NiPr) (Et, H, Et-Pyr) 3;
The precursor has the formula Nb (═ NiPr) (nPr, H, nPr-Pyr) 3;
The precursor has the formula Nb (═ NiPr) (iPr, H, iPr-Pyr) 3;
The precursor has the formula Nb (═ NiPr) (tBu, H, tBu-Pyr) 3;
The precursor has the formula Nb (═ NiPr) (iBu, H, iBu-Pyr) 3;
The precursor has the formula Nb (═ NiPr) (nBu, H, nBu-Pyr) 3;
The precursor has the formula Nb (═ NiPr) (sBu, H, sBu-Pyr) 3;
The precursor has the formula Nb (═ NiPr) (tAmyl, H, tAmyl-Pyr) 3;
The precursor has the formula Nb (═ NiPr) (iPr, H, tBu-Pyr) 3;
The precursor has the formula Nb (═ NiPr) (iPr, H, Me-Pyr) 3;
The precursor has the formula Nb (═ NiPr) (iPr, H, Et-Pyr) 3;
The precursor has the formula Nb (═ NiPr) (TMS, H, TMS-Pyr) 3;
The precursor has the formula Nb (═ NiPr) (DMS, H, DMS-Pyr) 3;
The precursor has the formula Nb (═ NiPr) (MMS, H, MMS-Pyr) 3;
The precursor has the formula Nb (═ NtBu) (H, H, H-Pyr) 3;
The precursor has the formula Nb (NtBu) (Me, H, H-Pyr) 3;
The precursor has the formula Nb (NtBu) (Me, H, Me-Pyr) 3;
The precursor has the formula Nb (NtBu) (Me, Me, Me-Pyr) 3;
The precursor has the formula Nb (═ NtBu) (Et, H, Et-Pyr) 3;
The precursor has the formula Nb (═ NtBu) (nPr, H, nPr-Pyr) 3;
The precursor has the formula Nb (═ NtBu) (iPr, H, iPr-Pyr) 3;
The precursor has the formula Nb (═ NtBu) (tBu, H, tBu-Pyr) 3;
The precursor has the formula Nb (═ NtBu) (sBu, H, sBu-Pyr) 3;
The precursor has the formula Nb (═ NtBu) (nBu, H, nBu-Pyr) 3;
The precursor has the formula Nb (═ NtBu) (iBu, H, iBu-Pyr) 3;
The precursor has the formula Nb (═ NtBu) (tAmyl, H, tAmyl-Pyr) 3;
The precursor has the formula Nb (═ NtBu) (iPr, H, tBu-Pyr) 3;
The precursor has the formula Nb (═ NtBu) (iPr, H, Me-Pyr) 3;
The precursor has the formula Nb (═ NtBu) (iPr, H, Et-Pyr) 3;
The precursor has the formula Nb (═ NtBu) (TMS, H, TMS-Pyr) 3;
The precursor has the formula Nb (═ NtBu) (DMS, H, DMS-Pyr) 3;
The precursor has the formula Nb (═ NtBu) (MMS, H, MMS-Pyr) 3;
The precursor has the formula Nb (═ NtAmyl) (H, H, H-Pyr) 3;
The precursor has the formula Nb (═ NtAmyl) (Me, H, H-Pyr) 3;
The precursor has the formula Nb (═ NtAmyl) (Me, H, Me-Pyr) 3;
The precursor has the formula Nb (═ NtAmyl) (Me, Me, Me-Pyr) 3;
The precursor has the formula Nb (═ NtAmyl) (Et, H, Et-Pyr) 3;
The precursor has the formula Nb (═ NtAmyl) (nPr, H, nPr-Pyr) 3;
The precursor has the formula Nb (═ NtAmyl) (iPr, H, iPr-Pyr) 3;
The precursor has the formula Nb (═ NtAmyl) (tBu, H, tBu-Pyr) 3;
The precursor has the formula Nb (═ NtAmyl) (sBu, H, sBu-Pyr) 3;
The precursor has the formula Nb (═ NtAmyl) (nBu, H, nBu-Pyr) 3;
The precursor has the formula Nb (═ NtAmyl) (iBu, H, iBu-Pyr) 3;
The precursor has the formula Nb (═ NtAmyl) (tAmyl, H, tAmyl-Pyr) 3;
The precursor has the formula Nb (═ NtAmyl) (iPr, H, tBu-Pyr) 3;
The precursor has the formula Nb (═ NtAmyl) (iPr, H, Me-Pyr) 3;
The precursor has the formula Nb (═ NtAmyl) (iPr, H, Et-Pyr) 3;
The precursor has the formula Nb (═ NtAmyl) (TMS, H, TMS-Pyr) 3;
The precursor has the formula Nb (═ NtAmyl) (DMS, H, DMS-Pyr) 3;
The precursor has the formula Nb (═ NtAmyl) (MMS, H, MMS-Pyr) 3;
The niobium-containing film-forming composition comprises between about 95.0% w/w and about 100.0% w/w of the precursor;
the niobium-containing film-forming composition comprises between about 0.0% w/w and about 5.0% w/w impurities;
the niobium-containing film-forming composition comprises between about 0.0% w/w and about 2.0% w/w impurities;
the niobium-containing film-forming composition comprises between about 0.0% w/w and about 1.0% w/w impurities;
the impurities include pyrazoles; pyridine; an alkylamine; an alkyl imine; THF; an ether; pentane; cyclohexane; heptane; benzene; toluene; a chlorinated metal compound; lithium, sodium, or potassium pyrazolate;
the niobium-containing film-forming composition comprises between about 0.0% w/w and about 2.0% w/w pyrazole impurity;
the niobium-containing film-forming composition comprises between about 0.0% w/w and about 2.0% w/w pyridine impurities;
the niobium-containing film-forming composition comprises between about 0.0% w/w and about 2.0% w/w alkylamine impurities;
the niobium-containing film-forming composition comprises between about 0.0% w/w and about 2.0% w/w of an alkylenimine impurity;
the niobium-containing film-forming composition comprises between about 0.0% w/w and about 2.0% w/w THF impurity;
the niobium-containing film-forming composition comprises between about 0.0% w/w and about 2.0% w/w of an ether impurity;
the niobium-containing film-forming composition comprises between about 0.0% w/w and about 2.0% w/w pentane impurities;
the niobium-containing film-forming composition comprises between about 0.0% w/w and about 2.0% w/w cyclohexane impurity;
the niobium-containing film-forming composition comprises between about 0.0% w/w and about 2.0% w/w heptane impurities;
the niobium-containing film-forming composition comprises between about 0.0% w/w and about 2.0% w/w benzene impurity;
the niobium-containing film-forming composition comprises between about 0.0% w/w and about 2.0% w/w toluene impurity;
the niobium-containing film-forming composition comprises between about 0.0% w/w and about 2.0% w/w of chlorinated metal compound impurities;
the niobium-containing film-forming composition comprises between about 0.0% w/w and about 2.0% w/w of a pyrazolyl lithium, pyrazolyl sodium, or pyrazolyl potassium impurity;
the niobium-containing film-forming composition comprises between about 0ppbw and about 1ppmw of metal impurities;
the niobium-containing film-forming composition comprises between about 0ppbw and about 500ppbw of metal impurities;
these metallic impurities include aluminum (Al), arsenic (As), barium (Ba), beryllium (Be), bismuth (Bi), cadmium (Cd), calcium (Ca), chromium (Cr), cobalt (Co), copper (Cu), gallium (Ga), germanium (Ge), hafnium (Hf), zirconium (Zr), indium (In), iron (Fe), lead (Pb), lithium (Li), magnesium (Mg), manganese (Mn), tungsten (W), nickel (Ni), potassium (K), sodium (Na), strontium (Sr), thorium (Th), tin (Sn), titanium (Ti), uranium (U), and zinc (Zn);
the niobium-containing film-forming composition comprises between about 0ppbw and about 500ppbw of Al impurities;
the niobium-containing film-forming composition comprises between about 0ppbw and about 500ppbw of As impurities;
the niobium-containing film-forming composition comprises between about 0ppbw and about 500ppbw of Ba impurities;
the niobium-containing film-forming composition comprises between about 0ppbw and about 500ppbw of the Be impurity;
the niobium-containing film-forming composition comprises between about 0ppbw and about 500ppbw of Bi impurities;
the niobium-containing film-forming composition comprises between about 0ppbw and about 500ppbw of a Cd impurity;
the niobium-containing film-forming composition comprises between about 0ppbw and about 500ppbw of Ca impurities;
the niobium-containing film-forming composition comprises between about 0ppbw and about 500ppbw of Cr impurities;
the niobium-containing film-forming composition comprises between about 0ppbw and about 500ppbw of Co impurities;
the niobium-containing film-forming composition comprises between about 0ppbw and about 500ppbw of Cu impurities;
the niobium-containing film-forming composition comprises between about 0ppbw and about 500ppbw of Ga impurities;
the niobium-containing film-forming composition comprises between about 0ppbw and about 500ppbw of Ge impurities;
the niobium-containing film-forming composition comprises between about 0ppbw and about 500ppbw of Hf impurities;
the niobium-containing film-forming composition comprises between about 0ppbw and about 500ppbw of Zr impurities;
the niobium-containing film-forming composition comprises between about 0ppbw and about 500ppbw of In impurities;
the niobium-containing film-forming composition comprises between about 0ppbw and about 500ppbw of Fe impurities;
the niobium-containing film-forming composition comprises between about 0ppbw and about 500ppbw of Pb impurity;
the niobium-containing film-forming composition comprises between about 0ppbw and about 500ppbw of Li impurities;
the niobium-containing film-forming composition comprises between about 0ppbw and about 500ppbw of Mg impurities;
the niobium-containing film-forming composition comprises between about 0ppbw and about 500ppbw of Mn impurities;
the niobium-containing film-forming composition comprises between about 0ppbw and about 500ppbw of W impurities;
the niobium-containing film-forming composition comprises between about 0ppbw and about 500ppbw of Ni impurities;
the niobium-containing film-forming composition comprises between about 0ppbw and about 500ppbw of K impurity;
the niobium-containing film-forming composition comprises between about 0ppbw and about 500ppbw of Na impurities;
the niobium-containing film-forming composition comprises between about 0ppbw and about 500ppbw of Sr impurities;
the niobium-containing film-forming composition comprises between about 0ppbw and about 500ppbw of the Th impurity;
the niobium-containing film-forming composition comprises between about 0ppbw and about 500ppbw of Sn impurities;
the niobium-containing film-forming composition comprises between about 0ppbw and about 500ppbw of Ti impurities;
the niobium-containing film-forming composition comprises between about 0ppbw and about 500ppbw of U impurities; and is
The niobium-containing film-forming composition comprises between about 0ppbw and about 500ppbw of Zn impurities.
Also disclosed are niobium film-forming composition delivery devices comprising a canister having an inlet conduit and an outlet conduit and containing any of the niobium film-forming compositions disclosed above. The disclosed delivery devices may include one or more of the following aspects:
one end of the inlet conduit is located above the surface of the niobium film-forming composition and one end of the outlet conduit is located above the surface of the niobium film-forming composition;
one end of the inlet conduit is located above the surface of the niobium film-forming composition and one end of the outlet conduit is located below the surface of the niobium film-forming composition;
one end of the inlet conduit is located below the surface of the niobium film-forming composition and one end of the outlet conduit is located above the surface of the niobium film-forming composition.
Methods for depositing niobium-containing films on a substrate are also disclosed. One or more of the above-disclosed niobium-containing film-forming compositions are introduced into a reactor in which a substrate is disposed. Depositing at least a portion of the precursor onto a substrate to form a niobium-containing layer. The disclosed processes may further include one or more of the following:
introducing reactants into the reactor;
subjecting the reactant to plasma treatment;
the reactants are not plasma treated;
subjecting the reactant to remote plasma treatment;
the reactant is selected from the group H consisting of 2、H 2CO、N 2H 4、NH 3Hydrogen radicals, primary amines, secondary amines, tertiary amines, trisilylamine, and mixtures thereof;
the reactant is H 2;
The reactant is NH 3;
The reactant is selected from the group consisting of: o is 2、O 3、H 2O、H 2O 2、NO、N 2O、NO 2Oxygen radicals thereof, and mixtures thereof;
the reactant is H 2O;
The reactant is plasma-treated O 2;
The reactant is O 3;
Introducing the niobium containing precursor and the reactant sequentially into a chamber;
the introduction of the niobium-containing precursor and the introduction of the reactant are separated in time or space by an inert gas purge to avoid gas-phase mixing of the reactant and the Nb-containing precursor;
introducing another precursor into the reactor;
the second precursor comprises an element M selected from a group IV element, another group V element, Si, Ge, Al, or any lanthanide;
the niobium-containing film and the second precursor form a stack;
the niobium-containing film and the second precursor form a NbO/MO stack;
the reactor is configured for atomic layer deposition;
the reactor is configured for plasma enhanced atomic layer deposition;
the reactor is configured for spatial atomic layer deposition;
the niobium-containing film is Nb nO mWherein n and m are each integers ranging from 1 to 6 inclusive;
the niobium-containing film is NbO 2Or Nb 2O 5;
The niobium-containing film is Nb oN pWherein o and p are each an integer ranging from 1 to 6 inclusive;
the niobium-containing film is NbN;
the niobium-containing film is Nb oN pO qWherein o, p and q are each integers ranging from 1 to 6 inclusive;
the niobium-containing film is NbON;
the niobium-containing film is NbMO, where M is a group IV element, a different group V element, Si, Ge, Al, or any lanthanide.
Drawings
For a further understanding of the nature and objects of the present invention, reference should be made to the following detailed description taken in conjunction with the accompanying drawings in which:
FIG. 1 shows niobium (tert-butylimino) tris (3, 5-dimethylpyrazolyl) [ Nb (═ NtBu) (Me, H, Me-Pyr) 3]Is/are as follows 1HNMR spectra;
FIG. 2 shows Nb (═ NtBu) (Me, H, Me-Pyr) 3Thermogravimetric analysis (TGA) profile of the percentage of weight loss with temperature increase;
FIG. 3 shows Nb (═ NtBu) (Me, H, Me-Pyr) 3Differential Scanning Calorimetry (DSC) profile of melting point and decomposition temperature of (a);
FIG. 4 is niobium (tert-amylimino) tris (3, 5-dimethylpyrazolyl) [ Nb (═ NtAm) (Me, H, Me-Pyr) 3]Is/are as follows 1HNMR spectra;
FIG. 5 shows Nb (═ NtAm) (Me, H, Me-Pyr) 3TGA profile of the percentage of weight loss with temperature increase;
FIG. 6 shows niobium (t-butylimino) tris (3, 5-diisopropylpyrazolyl) [ Nb (═ NtBu) (iPr, H, iPr-Pyr) 3]Is/are as follows 1HNMR spectra;
FIG. 7 shows Nb (═ NtBu) (iPr, H, iPr-Pyr) 3TGA profile of the percentage of weight loss with temperature increase;
FIG. 8 shows Nb (═ NtBu) (iPr, H, iPr-Pyr) 3DSC plots of melting point and decomposition temperature of (a);
FIG. 9 shows the use of Nb (═ NtBu) (iPr, H, iPr-Pyr) 3A graph of the growth rate and% non-uniformity of the niobium nitride film as a function of chamber temperature in the case of (1);
FIG. 10 shows the use of Nb (═ NtBu) (iPr, H, iPr-Pyr) 3A plot of the growth rate of niobium nitride films as a function of precursor source introduction time at 375 ℃;
FIG. 11 shows the use of Nb (═ NtBu) (NEt) 2) 3And Nb (═ NtBu) (iPr, H, iPr-Pyr) 3A plot of the growth rate of the niobium nitride film as a function of chamber temperature per ALD cycle number is used in the case of (1);
FIG. 12 shows the use of Nb (═ NtBu) (iPr, H, iPr-Pyr) 3In the case of (2), Nb 2O 5Plots of film growth rate (diamonds) and non-uniformity (circles) as a function of chamber temperature;
FIG. 13 is Nb produced at 300 ℃ 2O 5X-ray spectroscopy (XPS) graph of the film;
FIG. 14 is Nb produced at 325 deg.C 2O 5XPS profile of the film;
FIG. 15a is a Nb formed over a structure having an aspect ratio of 1:15 2O 5A Scanning Electron Microscope (SEM) image of the film;
FIG. 15b is a close-up SEM image of the top of the structure of FIG. 15 a;
FIG. 15c is a close-up SEM image of the bottom of the structure of FIG. 15 a;
FIG. 16 is a side view of one embodiment of a liquid niobium-containing film-forming
FIG. 17 is a side view of a second embodiment of a niobium-containing film forming
FIG. 18 is an exemplary embodiment of a
Detailed Description
Disclosed are compositions for forming niobium-containing films comprising precursors having the formula:
r, R therein 1、R 2And R 3Each independently is H, alkyl, or R' 3Si, wherein each R' is independently H or alkyl. As shown in the formula, the nitrogen atom may be bonded to the niobium atom, resulting in a tetracoordinated nb (v) center. The resulting geometry may be tetrahedral, where the center of the nitrogen-nitrogen bond in each 3, 5-dialkylpyrazolyl moiety is believed to be a monodentate ligand. The carbon atom in the pyrazole ligand may be sp 2Hybridization results in a delocalized charge on the monoanionic ligand, where Nb can be considered to be coordinated by the η 5-bonded pyrazole ring.
Alternatively, the carbon atom in the pyrazolyl ligand can be sp3 hybridized or some combination of sp2 and sp3 hybridized, resulting in a negative charge on one of the nitrogen atoms and in a neutral charge on the other nitrogen atom. In this embodiment, the formula may be
For convenience, delocalized bonds are depicted in the following manner. Alternatively, however, each formula may be represented by this formula (showing a single bond between N and Nb).
When R ═ iPr, the precursor for forming the niobium-containing film may have the formula Nb (═ NiPr) (R) 1,R 2,R 3-Pyr) 3:
Wherein R is 1、R 2And R 3Each independently is H, alkyl, or SiR' 3Wherein each R' is independently H or alkyl. Preferably, R 1、R 2And R 3Each independently of the others is H, Me, Et, nPr, iPr, tBu, sBu, iBu, nBu, tAmyl, SiMe 3、SiMe 2H. Or SiH 2Me。
Exemplary precursors include Nb (═ NiPr) (H, H-Pyr) 3、Nb(=NiPr)(Me,H,H-Pyr) 3、Nb(=NiPr)(Me,H,Me-Pyr) 3、Nb(=NiPr)(Me,Me,Me-Pyr) 3、Nb(=NiPr)(Et,H,Et-Pyr) 3、Nb(=NiPr)(nPr,H,nPr-Pyr) 3、Nb(=NiPr)(iPr,H,iPr-Pyr) 3、Nb(=NiPr)(tBu,H,tBu-Pyr) 3、Nb(=NiPr)(iBu,H,iBu-Pyr) 3、Nb(=NiPr)(nBu,H,nBu-Pyr) 3、Nb(=NiPr)(sBu,H,sBu-Pyr) 3、Nb(=NiPr)(tAmyl,H,tAmyl-Pyr) 3、Nb(=NiPr)(iPr,H,tBu-Pyr) 3、Nb(=NiPr)(iPr,H,Me-Pyr) 3、Nb(=NiPr)(iPr,H,Et-Pyr) 3、Nb(=NiPr)(TMS,H,TMS-Pyr) 3、Nb(=NiPr)(DMS,H,DMS-Pyr) 3Or Nb (═ NiPr) (MMS, H, MMS-Pyr) 3。
When R ═ tBu, the precursor for forming the niobium-containing film may have the formula Nb (═ NtBu) (R) 1,R 2,R 3-Pyr) 3:
Wherein R is 1、R 2And R 3Each independently is H, alkyl, or SiR' 3Wherein each R' is independently H or alkyl. Preferably, R 1、R 2And R 3Each independently of the others is H, Me, Et, nPr, iPr, tBu, sBu, iBu, nBu, tAmyl, SiMe 3、SiMe 2H. Or SiH 2Me。
Exemplary precursors include Nb (═ NtBu) (H, H-Pyr) 3、Nb(=NtBu)(Me,H,H-Pyr) 3、Nb(=NtBu)(Me,H,Me-Pyr) 3、Nb(=NtBu)(Me,Me,Me-Pyr) 3、Nb(=NtBu)(Et,H,Et-Pyr) 3、Nb(=NtBu)(nPr,H,nPr-Pyr) 3、Nb(=NtBu)(iPr,H,iPr-Pyr) 3、Nb(=NtBu)(tBu,H,tBu-Pyr) 3、Nb(=NtBu)(sBu,H,sBu-Pyr) 3、Nb(=NtBu)(nBu,H,nBu-Pyr) 3、Nb(=NtBu)(iBu,H,iBu-Pyr) 3、Nb(=NtBu)(tAmyl,H,tAmyl-Pyr) 3、Nb(=NtBu)(iPr,H,tBu-Pyr) 3、Nb(=NtBu)(iPr,H,Me-Pyr) 3、Nb(=NtBu)(iPr,H,Et-Pyr) 3、Nb(=NtBu)(TMS,H,TMS-Pyr) 3、Nb(=NtBu)(DMS,H,DMS-Pyr) 3Or Nb (═ NtBu) (MMS, H, MMS-Pyr) 3。
When R ═ tAmyl, the precursor for forming the niobium-containing film may have the formula Nb (═ NtAmyl) (R) 1,R 2,R 3-Pyr) 3:
Wherein R is 1、R 2And R 3Each independently is H, alkyl, or SiR' 3Wherein each R' is independently H or alkyl. Preferably, R 1、R 2And R 3Each independently of the others is H, Me, Et, nPr, iPr, tBu, sBu, iBu, nBu, tAmyl, SiMe 3、SiMe 2H. Or SiH 2Me。
Exemplary precursors include Nb (═ NtAmyl) (H, H-Pyr) 3、Nb(=NtAmyl)(Me,H,H-Pyr) 3、Nb(=NtAmyl)(Me,H,Me-Pyr) 3、Nb(=NtAmyl)(Me,Me,Me-Pyr) 3、Nb(=NtAmyl)(Et,H,Et-Pyr) 3、Nb(=NtAmyl)(nPr,H,nPr-Pyr) 3、Nb(=NtAmyl)(iPr,H,iPr-Pyr) 3、Nb(=NtAmyl)(tBu,H,tBu-Pyr) 3、Nb(=NtAmyl)(sBu,H,sBu-Pyr) 3、Nb(=NtAmyl)(nBu,H,nBu-Pyr) 3、Nb(=NtAmyl)(iBu,H,iBu-Pyr) 3、Nb(=NtAmyl)(tAmyl,H,tAmyl-Pyr) 3、Nb(=NtAmyl)(iPr,H,tBu-Pyr) 3、Nb(=NtAmyl)(iPr,H,Me-Pyr) 3、Nb(=NtAmyl)(iPr,H,Et-Pyr) 3、Nb(=NtAmyl)(TMS,H,TMS-Pyr) 3、Nb(=NtAmyl)(DMS,H,DMS-Pyr) 3Or Nb (═ NtAmyl) (MMS, H, MMS-Pyr) 3。
These precursors may be substituted by Nb (═ NR) X 3(py) 2With 3 equivalents of Z (R) 1,R 2,R 3Pyr), wherein X is a halogen selected from the group consisting of: F. cl, Br and I; z is an alkali metal selected from the group consisting of: li, Na and K; and R, R 1、R 2And R 3As defined above. Nb (═ NR) X 3(py) 2Can be used, for example, in Chemische Berichte]Vol.127, No. 7, 1994,1201-12. Z (R) 1,R 2,R 3Pyr) can be reacted with the corresponding R by means of an alkali metal alkyl, such as n-butyllithium (nBuLi) 1,R 2,R 3Pyrazole reaction. The addition of the reactants can be carried out at a low temperature, which is below-50 ℃. The reaction may be carried out in a polar solvent such as THF or diethyl ether. The precursor can be separated from the alkali metal salt by extraction with a non-polar solvent such as pentane, hexane, cyclohexane, heptane, benzene and toluene. The resulting niobium-containing film-forming composition may be purified by vacuum sublimation, vacuum distillation, or by recrystallization in a suitable solvent, which is selected from the group consisting of, but not limited to: THF, diethyl ether, pentane, hexane, cyclohexane, heptane, benzene, toluene, or mixtures thereof.
The purity of the disclosed niobium-containing film-forming composition is greater than 95% w/w (i.e., 95.0% w/w to 100.0% w/w), preferably greater than 98% w/w (i.e., 98.0% w/w to 100.0% w/w), and more preferably greater than 99% w/w (i.e., 99.0% w/w to 100.0% w/w). One of ordinary skill in the art will recognize that purity can be determined by H NMR or gas or liquid chromatography coupled with mass spectrometry. The disclosed niobium-containing film-forming composition may contain any of the following impurities: pyrazole; pyridine; an alkylamine; an alkyl imine; THF; an ether; pentane; cyclohexane; heptane; benzene; toluene; a chlorinated metal compound; or lithium pyrazolyl, sodium pyrazolyl, or potassium pyrazolyl. The total amount of these impurities is below 5% w/w (i.e. 0.0% w/w to 5.0% w/w), preferably below 2% w/w (i.e. 0.0% w/w to 2.0% w/w), and more preferably below 1% w/w (i.e. 0.0% w/w to 1.0% w/w). The composition may be purified by recrystallization, sublimation, distillation, and/or passing the gas or liquid through a suitable adsorbent, such as 4A molecular sieve.
Purification of the disclosed niobium-containing film-forming compositions can also result in metal impurities at levels of 0 to 1ppmw, preferably 0 to 500ppbw (parts per million by weight). These metallic impurities include, but are not limited to, aluminum (Al), arsenic (As), barium (Ba), beryllium (Be), bismuth (Bi), cadmium (Cd), calcium (Ca), chromium (Cr), cobalt (Co), copper (Cu), gallium (Ga), germanium (Ge), hafnium (Hf), zirconium (Zr), indium (In), iron (Fe), lead (Pb), lithium (Li), magnesium (Mg), manganese (Mn), tungsten (W), nickel (Ni), potassium (K), sodium (Na), strontium (Sr), thorium (Th), tin (Sn), titanium (Ti), uranium (U), and zinc (Zn).
Methods for forming a niobium-containing layer on a substrate using a vapor deposition process are also disclosed. Applicants believe, and are demonstrated in the following deposition examples, that the disclosed niobium-containing film-forming compositions are suitable for atomic layer deposition. Specifically, the disclosed niobium-containing film-forming compositions are capable of surface saturation, self-limiting growth per cycle, and perfect step coverage over aspect ratios ranging from about 2:1 to about 200:1, and preferably from about 20:1 to about 100: 1. In addition, the disclosed niobium-containing film-forming composition has a high decomposition temperature, indicating its good thermal stability to enable ALD. The high decomposition temperature allows ALD at higher temperatures, resulting in a film with higher purity.
The method may be useful in the manufacture of semiconductor, photovoltaic, LCD-TFT, or flat panel devices. The disclosed compositions for forming niobium-containing films can be used to deposit niobium-containing films using any deposition method known to those skilled in the art. Examples of suitable vapor deposition methods include Chemical Vapor Deposition (CVD) or Atomic Layer Deposition (ALD). Exemplary CVD methods include thermal CVD, plasma enhanced CVD (pecvd), pulsed CVD (pcvd), low pressure CVD (lpcvd), sub-atmospheric CVD (sacvd), or atmospheric pressure CVD (apcvd), hot wire CVD (HWCVD, also known as cat-CVD), where the hot wire serves as an energy source for the deposition process, free radical bonded CVD, and combinations thereof. Exemplary ALD methods include thermal ALD, Plasma Enhanced ALD (PEALD), spatially isolated ALD, Hot Wire ALD (HWALD), free radical bonded ALD, and combinations thereof. Supercritical fluid deposition may also be used. The deposition method is preferably ALD, PE-ALD, or spatial ALD in order to provide suitable step coverage and film thickness control.
The disclosed niobium-containing film-forming compositions can be supplied in pure form or as a blend with a suitable solvent such as ethylbenzene, xylene, mesitylene, decalin, decane, or dodecane. The disclosed precursors may be present in the solvent in varying concentrations.
The pure or blended niobium film-forming composition is introduced into the reactor in vapor form by conventional means such as piping and/or flow meters. The vapor form may be produced by vaporizing the neat or blended composition by conventional vaporization steps (e.g., direct vaporization, distillation), or by bubbling, or by using a sublimator (e.g., the sublimator disclosed in PCT publication WO2009/087609 to Xu et al). The neat or blended composition may be fed as a liquid to a vaporizer where it is vaporized and then introduced into the reactor. Alternatively, the neat or blended composition may be vaporized by delivering a carrier gas into a container containing the composition or by bubbling a carrier gas into the composition. The carrier gas may include, but is not limited to, Ar, He, N 2And mixtures thereof. Sparging with a carrier gas can also remove any dissolved oxygen present in the neat or blended composition. The carrier gas and composition are then introduced into the reactor as a vapor.
If necessary, a container containing the disclosed composition can be heated to a temperature that allows the composition to be in its liquid phase and have sufficient vapor pressure. The container may be maintained at a temperature in the range of, for example, about 0 ℃ to about 180 ℃. Those skilled in the art will recognize that the temperature of the container may be adjusted in a known manner to control the amount of precursor vaporized.
The niobium film-forming composition can be delivered to a semiconductor processing tool by the disclosed niobium film-forming composition delivery apparatus. Fig. 16 and 17 show two embodiments of the disclosed
FIG. 16 is a side view of one embodiment of a niobium-containing film forming
Suitable valves include spring loaded valves or tethered diaphragm valves. The valve may further include a flow restriction orifice (RFO). The
When closed, the
In fig. 16, the
FIG. 17 is a side view of a second embodiment of a niobium-containing film forming
Both fig. 16 and 17 include
In another alternative, if the niobium-containing film-forming
When these niobium-containing film-forming compositions are solids, their vapors can be delivered to the reactor using a sublimator. Fig. 30 illustrates one embodiment of a
As shown in fig. 18, the
Assembled
As shown, the
While fig. 30 discloses one embodiment of a sublimator capable of delivering vapor of any solid niobium film-forming composition to the reactor, one of ordinary skill in the art will recognize that other sublimator designs are also suitable without departing from the teachings herein. Finally, one of ordinary skill in the art will recognize that the disclosed niobium-containing film-forming
The reactor may be any enclosure or chamber within an apparatus in which the deposition process takes place, such as but not limited to: parallel plate type reactors, cold wall type reactors, hot wall type reactors, single wafer reactors, multi-wafer reactors, or other types of deposition systems under conditions suitable to cause the compounds to react and form a layer. One of ordinary skill in the art will recognize that any of these reactors may be used for ALD or CVD deposition processes.
The reactor contains one or more substrates on which the film is deposited. A substrate is generally defined as a material on which a process is performed. The substrate may be any substrate suitable for use in the manufacture of semiconductors, photovoltaic materials, flat panels or LCD-TFT devices. Examples of suitable substrates include wafers, such as silicon, silicon dioxide, glass, or GaAs wafers. The wafer may have one or more layers of different materials deposited thereon from previous fabrication steps. For example, the wafers may include a silicon layer (crystalline, amorphous, porous, etc.), a silicon oxide layer, a silicon nitride layer, a silicon oxynitride layer, a carbon-doped silicon oxide (SiCOH) layer, a metal or metal nitride layer: (Ti, Ru, Ta, etc.) or combinations thereof. Additionally, the wafer may include a copper layer or a noble metal layer (e.g., platinum, palladium, rhodium, or gold). The wafer may include barrier layers such as manganese, manganese oxide, and the like. Plastic layers may also be used, such as poly (3, 4-ethylenedioxythiophene) poly (styrenesulfonate) [ PEDOT: PSS]. These layers may be planar or patterned. The disclosed methods may deposit the niobium-containing layer directly on the wafer or directly on one or more layers on top of the wafer (when the patterned layer forms the substrate). Further, one of ordinary skill in the art will recognize that the term "film" or "layer" as used herein refers to the thickness of some material placed or spread over a surface and that the surface may be a trench or line. Throughout this specification and claims, the wafer and any associated layers thereon are referred to as a substrate. For example, a niobium oxide film may be deposited on the metal oxide layer (e.g., ZrO) 2Layer, HfO 2Layer, or MoO 2Layer) on the substrate. In subsequent processing, another metal oxide layer may be deposited over the niobium oxide layer to form a stack. ZrO (ZrO) 2/Nb 2O 5/ZrO 2The stacked dielectric stack is typically a DRAM high-k stack. A conductive metal nitride layer (such as a niobium nitride layer or a titanium nitride layer) may be deposited previously or over the last metal oxide layer to form the bottom and top electrodes, respectively. The resulting NbN/ZrO 2/Nb 2O 5/ZrO 2the/NbN stack can be used in DRAM capacitors. Other conductive films, such as RuO, Ru, Pt, Ir, WN, WNC, alone or with NbN or TaN layers, may also be used as bottom or top electrodes.
The temperature and pressure within the reactor are maintained under conditions suitable for atomic layer deposition. In other words, after introducing the vaporized composition into the chamber, the conditions within the chamber are such that at least a portion of the precursor is deposited onto the substrate to form the niobium-containing layer. For example, the pressure in the reactor may be maintained at about 1Pa to about 10 Pa depending on the deposition parameters required 5Pa, more preferably between about 25Pa and about 10 Pa 3Pa is between Pa. Also, the temperature in the reactor may be maintained between about 100 ℃ and about 500 ℃, preferably at about 100 ℃Between 150 ℃ and about 400 ℃. One of ordinary skill in the art will recognize that "depositing at least a portion of the precursor" means that some or all of the precursor reacts with or adheres to the substrate.
The temperature of the reactor may be controlled by controlling the temperature of the substrate holder or controlling the temperature of the reactor wall. Devices for heating substrates are known in the art. The reactor walls are heated to a sufficient temperature to obtain the desired film at a sufficient growth rate and in the desired physical state and composition. Non-limiting exemplary temperature ranges to which the reactor wall may be heated include from about 100 ℃ to about 500 ℃. When a plasma deposition process is utilized, the deposition temperature may range from about 150 ℃ to about 400 ℃. Alternatively, the deposition temperature may range from about 200 ℃ to about 500 ℃ when performing the thermal process.
In addition to the disclosed niobium-containing film-forming composition, reactants can also be introduced into the reactor. When the target is a conductive film, the reactant may be H 2、H 2CO、N 2H 4、NH 3Primary amines, secondary amines, tertiary amines, trisilylamine, radicals thereof, and mixtures thereof. Preferably, the reactant is H 2Or NH 3。
Alternatively, when the target is a dielectric film, the reactant may be an oxidizing gas, such as O 2、O 3、H 2O、H 2O 2、NO、N 2O、NO 2Oxygen-containing free radical (such as O.or OH.), carboxylic acid, formic acid, acetic acid, propionic acid, and mixtures thereof. Preferably, the oxidizing gas is selected from the group consisting of: o is 3、H 2O 2Or H 2O。
The reactants may be treated by plasma to decompose the reactants into their free radical forms. When treated with plasma, N 2May also be used as a nitrogen source gas. For example, the plasma may be generated at a power ranging from about 50W to about 500W, preferably from about 100W to about 400W. The plasma may be generated or present within the reactor itself. Alternatively, the plasmaMay typically be located at a location remote from the reactor, for example, in a remotely located plasma system. Those skilled in the art will recognize methods and apparatus suitable for such plasma processing.
For example, the reactants may be introduced into a direct plasma reactor (the reactor generating a plasma in a reaction chamber) to produce a plasma treated reactant in the reaction chamber. Exemplary direct plasma reactors include Titan manufactured by Town Technologies TMA PECVD system. The reactants may be introduced and maintained in the reaction chamber prior to plasma processing. Alternatively, the plasma processing may occur simultaneously with the introduction of the reactants. The in-situ plasma is typically a 13.56MHz RF inductively coupled plasma generated between the showerhead and the substrate holder. The substrate or showerhead may be a powered electrode depending on whether or not a positive ion collision occurs. The power typically used in an in situ plasma generator is from about 30W to about 1000W. Preferably, from about 30W to about 600W of power is used in the disclosed method. More preferably, the power ranges from about 100W to about 500W. Dissociation of reactants using an in-situ plasma is typically less than that achieved using a remote plasma source for the same power input, and thus is less effective in reactant dissociation than a remote plasma system, which may be advantageous for depositing niobium-containing films on substrates that are susceptible to plasma damage.
Alternatively, the plasma treated reactant may be generated outside the reaction chamber. MKS instruments Ltd
The reactive gas generator may be used to treat the reactants prior to passage into the reaction chamber. Operating at 2.45GHz, 7kW plasma power and pressures ranging from about 0.5 Torr to about 10 Torr, reactant O 2Decomposable into two O ·A free radical. Preferably, the remote plasma may be generated with a power ranging from about 1kW to about 10kW, more preferably from about 2.5kW to about 7.5 kW.Atomic layer deposition conditions within the chamber allow the disclosed Nb compositions adsorbed or chemisorbed to the substrate surface to react and form a niobium-containing film on the substrate. In some embodiments, applicants believe that plasma treating the reactants can provide the reactants with the energy required to react with the disclosed compositions.
Additional precursor compounds may be introduced into the reactor depending on which type of film is desired to be deposited. The precursor can be used to provide additional elements to the niobium-containing film. The additional elements may include lanthanides (ytterbium, erbium, dysprosium, gadolinium, praseodymium, cerium, lanthanum, yttrium), group IV elements (zirconium, titanium, hafnium), main group elements (germanium, silicon, aluminum), additional group V elements (tantalum, vanadium), or mixtures of these. When additional precursor compounds are utilized, the resulting film deposited on the substrate contains niobium metal in combination with additional elements. Nanolaminate films were obtained when additional precursors and Nb precursors were used in more than one ALD overcycling sequence.
The niobium-containing film-forming composition and the reactants may be introduced sequentially into the reactor (atomic layer deposition). Between the introduction of each Nb-containing film-forming composition, any additional precursors, and reactants, the reactor may be purged with an inert gas. Another example is the continuous introduction of reactants and the formation of a niobium-containing film composition by pulsed introduction while sequentially activating the reactants with a plasma, provided that the Nb composition and the unactivated reactants do not substantially react under chamber temperature and pressure conditions (CW PEALD).
Each pulse of the composition may last for a period of time ranging from about 0.01 seconds to about 120 seconds, alternatively from about 1 second to about 60 seconds, alternatively from about 5 seconds to about 30 seconds. The reactants may also be pulsed into the reactor. In such embodiments, the pulses of each substance may last for a period of time ranging from about 0.01 seconds to about 120 seconds, alternatively from about 1 second to about 30 seconds, alternatively from about 2 seconds to about 20 seconds. In another alternative, the vaporized composition and reactants may be ejected simultaneously from different parts of the showerhead (without mixing of the composition and reactants), keeping the susceptors of several wafers rotating under the showerhead (spatial ALD).
Deposition may be performed for different lengths of time depending on the particular process parameters. Generally, deposition can be continued for a desired or necessary length of time to produce a film having the necessary characteristics. Typical film thicknesses can vary from a few angstroms to hundreds of microns, and typically from 2 to 100nm, depending on the particular deposition process. The deposition process may also be performed as many times as necessary to obtain the desired film.
In one non-limiting exemplary ALD process, a vapor phase of the disclosed niobium-containing film-forming composition is introduced into a reactor where it is contacted with a suitable substrate. Excess composition may then be removed from the reactor by purging and/or evacuating the reactor. Reacting a reactant (e.g. NH) 3) Is introduced into a reactor where it is allowed to react in a self-limiting manner with the absorbed composition. Any excess reactants are removed from the reactor by purging and/or evacuating the reactor. If the desired film is niobium nitride, this two-step process may provide the desired film thickness or may be repeated until a film having the necessary thickness is obtained.
Alternatively, if the desired film contains the transition metal niobium and the second element, the vapor of the additional precursor compound may be introduced into the reactor after the above two-step process. Additional precursor compounds will be selected based on the properties of the deposited niobium-containing film. After introduction into the reactor, the additional precursor compound is contacted with the substrate. Any excess precursor compound is removed from the reactor by purging and/or evacuating the reactor. Again, reactants may be introduced into the reactor to react with the precursor compounds. Excess reactants are removed from the reactor by purging and/or evacuating the reactor. If the desired film thickness has been achieved, the process can be terminated. However, if a thicker film is desired, the entire four-step process may be repeated. By alternating the provision of the niobium-containing film-forming composition, additional precursor compounds, and reactants, films of desired composition and thickness can be deposited.
An exemplary ALD process becomes an exemplary PEALD process when the reactants in this exemplary ALD process are treated with plasma. The reactants can be treated with the plasma before or after introduction into the chamber.
In a second non-limiting exemplary ALD process, one of the disclosed niobium-containing film-forming compositions (e.g., niobium (t-butylimino) tris (3, 5-diisopropylpyrazolyl) (Nb (═ NtBu) (iPr, H, iPr-Pyr) 3) ) is introduced into a reactor where the composition is contacted with the Si substrate. Excess composition may then be removed from the reactor by purging and/or evacuating the reactor. Reacting a reactant (e.g. NH) 3) Introduced into a reactor where it reacts in a self-limiting manner with the absorbed composition to form a niobium nitride film. Removing any excess NH from the reactor by purging and/or evacuating the reactor 3A gas. These two steps may be repeated until the niobium nitride film achieves the desired thickness, typically about 10 angstroms. ZrO may then be deposited on the NbN film 2. For example ZrCp (NMe) 2) 3May serve as Zr precursor. May then be at ZrO 2Repeat the above description using Nb (═ NtBu) (iPr, H, iPr-Pyr) 3And NH 3The second non-limiting exemplary ALD process of (a). The resulting NbN/ZrO 2the/NbN stack can be used in DRAM capacitors.
In another exemplary ALD process, another precursor may be introduced sequentially between one or several ALD super-cycles (e.g., O-containing reactant/Nb precursor/O-containing reactant) to deposit a NbMO film or NbO/MO nanolaminate, M being selected from a group IV element, a different group V element, silicon, germanium, aluminum, or any lanthanide. The selected M precursor is preferably subjected to ALD growth within the same temperature window exhibited by the selected Nb-containing film-forming composition.
The niobium-containing film obtained from the process discussed above may comprise Nb, Nb kSi l、Nb nO m、Nb oN pOr Nb oN pO qWherein k, l, m, n, o, p, and q may each independently range from 1 to 6. Exemplary films include NbO 2、Nb 2O 5NbN, and NbON. One of ordinary skill in the artThe practitioner will recognize that the desired film composition can be obtained by judicious selection of the appropriate niobium-containing film-forming composition reactants. The NbN film may provide suitable step coverage for capacitor electrodes in DRAM, gate metal in 3D flash memory devices, heating elements in phase change memory, or electromigration barriers, gate metal, and contact layers in logic devices.
Once the desired film thickness is achieved, the film may be subjected to additional processing such as thermal annealing, furnace annealing, rapid thermal annealing, UV or electron beam curing, and/or plasma gas exposure. Those skilled in the art will recognize systems and methods for performing these additional processing steps. For example, the NbN film may be exposed to a temperature range from about 200 ℃ and about 1000 ℃ for a time from about 0.1 seconds to about 7200 seconds under an inert atmosphere, an N-containing atmosphere, or a combination thereof. Most preferably, the temperature is 400 ℃ for 3600 seconds under an inert or N-containing atmosphere. The resulting film may contain fewer impurities and thus may have improved density, resulting in improved leakage current. The annealing step may be performed in the same reaction chamber in which the deposition process is performed. Alternatively, the substrate may be removed from the reaction chamber, with the annealing/rapid annealing process being performed in a separate apparatus. Any of the above post-treatment methods, but particularly thermal annealing, have been found to effectively reduce carbon and nitrogen contamination of the NbN film. This in turn tends to improve the resistivity of the film.
After annealing, NbN films deposited by any of the disclosed processes can have a bulk resistivity of about 50 μ ohm-cm to about 1,000 μ ohm-cm at room temperature. The room temperature is about 20 ℃ to about 28 ℃ depending on the season. The bulk resistivity is also referred to as volume resistivity. One of ordinary skill in the art will recognize that bulk resistivity is measured at room temperature on NbN films, which are typically about 50nm thick. Bulk resistivity typically increases for thinner films due to changes in the electron transport mechanism. At higher temperatures, the bulk resistivity also increases.
In another alternative, the disclosed compositions may be used as dopants or implants. A portion of the disclosed composition may be deposited on top of a film to be dopedFor example indium oxide (In) 2O 3) Film, tantalum dioxide (TaO) 2) Film, vanadium dioxide (VO) 2) Film, titanium oxide film, copper oxide film or tin dioxide (SnO) 2) And (3) a membrane. Then, niobium diffuses into the film during the annealing step to form a niobium-doped film { (Nb) In 2O 3、(Nb)VO 2、(Nb)TiO、(Nb)CuO、(Nb)SnO 2}. See, for example, US 2008/0241575 to Lavoie et al, the doping method of which is incorporated herein by reference in its entirety. .
Examples of the invention
The following non-limiting examples are provided to further illustrate embodiments of the present invention. However, these examples are not intended to be inclusive of all examples and are not intended to limit the scope of the invention described herein.
Example 1: synthesis of niobium (tert-butylimino) tris (3, 5-dimethylpyrazolyl)
To a solution of 1H-3, 5-dimethylpyrazole (2g, 0.00214mol) in 40mL of THF at-78 deg.C was added dropwise nBuLi (14mL, 1.6M). After stirring overnight at room temperature, the mixture was added to Nb (═ NtBu) Cl at-78 ℃ 3(py) 2(3g, 0.00678mmol) in 500mL of THF. The mixture was stirred at room temperature overnight. The solvent was then removed in vacuo and the product was extracted with pentane to give a yellow solid. The material was then purified by sublimation at 25 mtorr up to 130 ℃ to yield 0.64g (20%) of a pure yellow solid. NMR is provided in FIG. 1 1And (4) H spectrum. NMR 1H(δ,ppm,C6D6):6.04(s,3H),2.31(s,18H),0.96(s,9H)。
During the open cup TGA analysis, the solids left 5.6% residual mass (15% during the closed cup) measured in an atmosphere of flowing nitrogen at a temperature rise rate of 10 ℃/min at 200 mL/min. These results are shown in figure 2, which is a TGA plot illustrating the percent weight loss as temperature is increased. As shown in fig. 3, the melting point determined using Differential Scanning Calorimetry (DSC) was about 95 ℃. Figure 3 also discloses that the temperature at which decomposition starts is 338 c, indicating its good thermal stability to enable ALD (without self-decomposition of the wafer surface).
Example 2: synthesis of niobium (tert-amylimino) tris (3, 5-dimethylpyrazolyl)
To a solution of 1H-3, 5-dimethylpyrazole (2g, 20.81mmol) in 40mL of THF at-78 deg.C was added dropwise nBuLi (14mL, 1.6M). After stirring at room temperature for 6hrs, the mixture was added to Nb (═ NtAmyl) Cl at-78 ℃ 3(py) 2(3g, 6.78mmol) in 30mL of THF. The mixture was stirred at room temperature overnight. The solvent was then removed in vacuo and the product was extracted with pentane to give a yellow solid. The material was then purified by sublimation at 25 mtorr up to 130 ℃ to yield 0.64g (20%) of a pure yellow solid. NMR is provided in FIG. 4 1And (4) H spectrum. NMR 1H(δ,ppm,C6D6):6.05(s,3H),2.32(s,18H),1.18(q,2H),0.93(s,6H),0.77(t,3H)。
During the open cup TGA analysis, the solids left 4.1% residual mass (15% during the closed cup) measured in an atmosphere of flowing nitrogen at a temperature rise rate of 10 ℃/min at 200 mL/min. These results are shown in figure 5, which is a TGA plot illustrating the percent weight loss as temperature is increased. Melting points were determined to be about 96 ℃ using DSC, indicating that the use of a tAmyl group does not help to reduce the melting point.
Example 3: synthesis of niobium (tert-butylimino) tris (3-methylpyrazolyl)
To a solution of 1H-3-methylpyrazole (1.8g, 21.92mmol) in 50mL of THF at room temperature was added freshly cut potassium tablets (0.94g, 24.04 mmol). After stirring at room temperature for 6hrs, the mixture was added to Nb (═ NtBu) Cl at-78 ℃ 3(py) 2(3g, 7.00mmol) in 40mL of THF. The mixture was stirred at room temperature overnight. The solvent was then removed in vacuo and the product was extracted with pentane to give a yellow solid. The material can then be subjected to sublimation at 20 mtorr up to 170 ℃, but the color changes to black and no material is collected.
Alternatively, nBuLi (14mL, 1.6M) was added dropwise to a solution of 1H-3-methylpyrazole (1.8g, 21.92mmol) in 50mL of THF at-78 ℃. After stirring at room temperature for 6hrs, the mixture was added to-78 deg.CNb (═ NtBu) Cl 3(py) 2(3g, 7.00mmol) in 40mL of THF. The mixture was stirred at room temperature overnight. The solvent was then removed in vacuo and the product was extracted with pentane to give an orange solid. The material can then be subjected to sublimation at 50 mtorr up to 150 ℃, but the color becomes dark brown and no material is collected.
Example 4: synthesis of niobium (tert-butylimino) tris (3, 5-diisopropylpyrazolyl)
To a solution of 1H-3, 5-diisopropylpyrazole (73g, 0.48mol) in 800mL of THF at-78 deg.C was added nBuLi (195mL, 2.5M) dropwise. After stirring overnight at room temperature, the mixture was added to Nb (═ NtBu) Cl at-78 ℃ 3(py) 2(66g, 0.154mol) in 500mL of THF. The mixture was stirred at room temperature overnight. The solvent was then removed in vacuo and the product was extracted with pentane to give a yellow oil. The material was then purified by distillation at 20 mtorr up to 220 ℃ to yield 72g (76%) of a pure yellow oil. NMR is provided in FIG. 6 1And (4) H spectrum. NMR 1H(δ,ppm,C6D6):6.17(s,3H),3.12(m,6H),1.27(d,36H),1.07(s,9H)。
During the TGA analysis in an open cup, an oil left 1.7% residual mass (15% during the closed cup) measured in an atmosphere of flowing nitrogen at a temperature rise rate of 10 ℃/min at 200 mL/min. These results are shown in figure 7, which is a TGA plot illustrating the percent weight loss as temperature is increased. As shown in fig. 8, the decomposition temperature was determined using DSC to start at about 430 ℃, indicating its good thermal stability to enable ALD (wafer surface is not self-decomposing).
The liquid state of such a precursor is unexpected. Gust et al reported Nb (═ NtBu) (tBu, H, tBu-Pyr) 3Is a white solid (polyhedrons)]20(2001)805 sub-assembly 813 at 806 sub-assembly 807). Example 1 demonstrates that the analogous Me product is also a solid (i.e., Nb (═ NtBu) (Me, H, Me-Pyr) 3). One of ordinary skill in the art would not expect the iPr substituent to produce a product with properties that differ from those of its Me or tBu analog. With Gust et al and example 1The unexpected liquid state of such a precursor may make vapor delivery of the precursor easier than the solid state of a similar precursor. More specifically, the liquid state may provide a more consistent and reproducible vapor concentration as compared to the solid state precursor. Furthermore, DSC analysis shows a surprisingly high thermal decomposition onset temperature (430 ℃), which makes this compound very suitable at high temperatures: (430 ℃)>ALD was performed at 300 deg.C).
Deposition example 1
Use of Nb (═ NtBu) (iPr, H, iPr-Pyr) on Si substrate 3And NH 3ALD deposition of (a). Nb (═ NtBu) (iPr, H, iPr-Pyr) 3The tank of (2) is maintained at 140 ℃. The chamber pressure was set at 0.5 torr. The process temperature is set at a temperature ranging from about 300 c to about 475 c. These results are shown in fig. 9, which shows the use of Nb (═ NtBu) (iPr, H, iPr-Pyr) 3A plot of NbN film growth rate as a function of chamber temperature. ALD deposition occurs at temperatures ranging from about 350 ℃ to about 400 ℃, with low non-uniformity over this temperature range. Figure 10 shows that the NbN film growth rate at 375 ℃ remains stable at about 0.34A/Cy with increasing precursor source introduction time. FIG. 11 shows the use of Nb (═ NtBu) (NEt) 2) 3And Nb (═ NtBu) (iPr, H, iPr-Pyr) 3In the case of (3), a plot of the growth rate of NbN films as a function of chamber temperature. As shown in fig. 11, from Nb (═ NtBu) (iPr, H, iPr-Pyr) 3NbN films of (a) are compared from Nb (═ NtBu) (NEt) 2) 3Is deposited at a temperature of about 200 c higher.
Deposition example 2
Use of Nb (═ NtBu) (iPr, H, iPr-Pyr) on Si substrate 3And O 3ALD deposition of (a). Nb (═ NtBu) (iPr, H, iPr-Pyr) 3The temperature of the tank of (a) was maintained at 115 ℃ and the process pressure was set at 0.5 torr. The ALD process temperature is set at a temperature ranging from about 250 ℃ to about 400 ℃, where the non-uniformity is low. FIG. 12 shows the use of Nb (═ NtBu) (iPr, H, iPr-Pyr) 3In the case of (2), Nb 2O 5Plot of growth rate (diamonds) and non-uniformity% (circles) of the film as a function of chamber temperature. Observed at up to 350 ℃To the ALD window. As shown in the XPS graphs of fig. 13 and 14, the films obtained at 300 ℃ and 325 ℃ contained C or N impurities below the detection limit of the analyzer, respectively.
Additional use of Nb (═ NtBu) (iPr, H, iPr-Pyr) was performed on Si substrates with a 1:15 aspect ratio 3And O 3ALD deposition of (a). Nb (═ NtBu) (iPr, H, iPr-Pyr) 3The temperature of the tank of (a) was maintained at 115 ℃ and the process pressure was set at 1 torr. The ALD process temperature was set at about 325 ℃. 100% step coverage was obtained. More specifically, as shown in FIGS. 15a-15c, 67nm Nb was measured at both the top and bottom of the 1:15 structure using a scanning electron microscope 2O 3And (3) a layer. Based on these results, applicants believe that a growth rate of 0.4A/cycle exhibits Nb (═ NtBu) (iPr, H, iPr-Pyr) 3The precursor will provide a well-controlled thickness of the NbN layer on any surface (e.g., Ru) on which good chemisorption occurs. More specifically, applicants contemplate the disclosure of Nb (═ NtBu) (iPr, H, iPr-Pyr) 3The precursor will chemisorb on the Ru surface with the same or better efficiency than on the Si surface in this example, and there is no substantial change in incubation time. As a result, the disclosed Nb (═ NtBu) (iPr, H, iPr-Pyr) 3The precursors would be well suited for deposition on Ru substrates with aspect ratios of 1:40, 1:50, or even 1:60 in DRAM structures.
It will be understood that many additional changes in the details, materials, steps and arrangement of parts, which have been herein described and illustrated in order to explain the nature of this invention, may be made by those skilled in the art within the principle and scope of the invention as expressed in the appended claims. Therefore, the invention is not intended to be limited to the specific embodiments in the examples given above and/or the drawings.
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