U.S. patent application number 15/130640 was filed with the patent office on 2016-10-20 for niobium-containing film forming compositions and vapor deposition of niobium-containing films.
The applicant listed for this patent is L'Air Liquide, Societe Anonyme pour l'Etude et l'Exploitation des Procedes Georges Claude. Invention is credited to Clement LANSALOT-MATRAS, Wontae NOH.
Application Number | 20160307904 15/130640 |
Document ID | / |
Family ID | 57128482 |
Filed Date | 2016-10-20 |
United States Patent
Application |
20160307904 |
Kind Code |
A1 |
LANSALOT-MATRAS; Clement ;
et al. |
October 20, 2016 |
NIOBIUM-CONTAINING FILM FORMING COMPOSITIONS AND VAPOR DEPOSITION
OF NIOBIUM-CONTAINING FILMS
Abstract
Niobium-containing film forming compositions are disclosed,
along with methods of synthesizing the same, and methods of forming
Niobium-containing films on one or more substrates via vapor
deposition processes using the Niobium-containing film forming
compositions.
Inventors: |
LANSALOT-MATRAS; Clement;
(Princeton, NJ) ; NOH; Wontae; (Seoul,
KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
L'Air Liquide, Societe Anonyme pour l'Etude et l'Exploitation des
Procedes Georges Claude |
Paris |
|
FR |
|
|
Family ID: |
57128482 |
Appl. No.: |
15/130640 |
Filed: |
April 15, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62148265 |
Apr 16, 2015 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C23C 16/18 20130101;
C23C 16/45525 20130101; H01L 27/1085 20130101; C23C 16/34 20130101;
C23C 16/50 20130101; H01G 4/20 20130101; H01L 21/28556 20130101;
H01L 21/28568 20130101; C23C 16/45553 20130101; C23C 16/42
20130101; C23C 16/405 20130101; C23C 16/32 20130101; H01G 4/10
20130101; H01G 13/003 20130101; H01L 28/60 20130101; H01L 27/10805
20130101 |
International
Class: |
H01L 27/108 20060101
H01L027/108; H01L 49/02 20060101 H01L049/02; C07F 9/00 20060101
C07F009/00; H01L 21/285 20060101 H01L021/285 |
Claims
1. A Niobium-containing film forming composition comprising a
precursor having the formula ##STR00012## wherein each R, R.sup.1,
R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6, and R.sup.7 are
independently H, an alkyl group, or R'.sub.3Si, with each R'
independently being H or an alkyl group
2. The Niobium-containing film forming composition of claim 1,
wherein R is tBu and R.sup.1-R.sup.5 is H.
3. The Niobium-containing film forming composition of claim 1,
wherein R is tBu, R.sup.1 is Me, and R.sup.2-R.sup.5 is H.
4. The Niobium-containing film forming composition of claim 1,
wherein R is tBu, R.sup.1 is Et, and R.sup.2-R.sup.5 is H.
5. The Niobium-containing film forming composition of claim 1,
wherein R is tBu, R.sup.1 is iPr, and R.sup.2-R.sup.5 is H.
6. The Niobium-containing film forming composition of claim 5,
wherein R is tBu, R.sup.1 is tBu, and R.sup.2-R.sup.5 is H.
7. The Niobium-containing film forming composition of claim 1,
wherein R is tBu, R.sup.1 is SiMe.sub.3, and R.sup.2-R.sup.5 is
H.
8. The Niobium-containing film forming composition of claim 1,
wherein R is tBu; R.sup.1, R.sup.3, and R.sup.5 are iPr; and
R.sup.2 and R.sup.4 are H.
9. The Niobium-containing film forming composition of claim 1,
wherein R.sup.1-R.sup.5 are H and R.sup.6 and R.sup.7 are
tAmyl.
10. The Niobium-containing film forming composition of claim 9,
wherein R is tBu.
11. A method of forming a Niobium-containing film, the method
comprising introducing into a reactor having a substrate therein a
vapor of the Niobium-containing film forming composition of claim
1; and depositing at least part of the precursor onto the
substrate.
12. The method of claim 11, further comprising introducing a
reactant into the reactor.
13. The method of claim 12, wherein the reactant is selected from
the group consisting of H.sub.2, H.sub.2CO, N.sub.2H.sub.4,
NH.sub.3, SiH.sub.4, Si.sub.2H.sub.6, Si.sub.3H.sub.8,
SiH.sub.2Me.sub.2, SiH.sub.2Et.sub.2, N(SiH.sub.3).sub.3, hydrogen
radicals thereof, and mixtures thereof.
14. The method of claim 12, wherein the reactant is selected from
the group consisting of O.sub.2, O.sub.3, H.sub.2O, H.sub.2O.sub.2,
NO, N.sub.2O, NO.sub.2, oxygen radicals thereof, and mixtures
thereof.
15. The method of claim 12, wherein the Niobium-containing film
forming composition and the reactant are introduced into the
reactor simultaneously and the reactor is configured for chemical
vapor deposition.
16. The method of claim 12, wherein the Niobium-containing film
forming composition and the reactant are introduced into the
chamber sequentially and the reactor is configured for atomic layer
deposition.
17. The method of claim 11, wherein the substrate is a dielectric
layer.
18. The method of claim 17, wherein the substrate is ZrO.sub.2 and
the Niobium-containing film forming composition is used to form a
DRAM capacitor.
19. The method of claim 12, further comprising plasma treating the
reactant.
20. The method of claim 12, wherein the Niobium-containing film
forming precursor is NbCp(=NtBu)(N(tAmyl)-CH--CH--N(tAmyl)) or
Nb(MeCp)(=NtBu)(N(tBu(N(tBu)-CH--CH--N(tBu)) and the reactant is
NH.sub.3 or O.sub.3.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims the benefit of U.S.
Provisional Application Ser. No. 62/148,265 filed Apr. 16, 2015,
being herein incorporated by reference in its entirety for all
purposes.
TECHNICAL FIELD
[0002] Niobium-containing film forming compositions are disclosed,
along with methods of synthesizing the same, and methods of forming
Niobium-containing films on one or more substrates via vapor
deposition processes using the Niobium-containing film forming
compositions.
BACKGROUND
[0003] Metal Oxide films, such as Niobium Oxide (Nb.sub.2O.sub.5),
have been extensively utilized in various fields of technology.
Traditionally these oxides have been applied as resistive films
used as high-k materials for insulating layers. For instance, a
thin layer of Nb.sub.2O.sub.5 between two ZrO.sub.2 dielectric
layers is expected to help significantly reduce leakage current and
stabilize the cubic/tetragonal phase of the ZrO.sub.2, affording
higher k values in the current MIM capacitor of a DRAM. (Alumina,
J. Vac. Sci. Technol A 4 (6), 1986 and Microelectronic Engineering
86 (2009) 1789-1795).
[0004] Metal Nitride films, such as Niobium Nitride (NbN.sub.x
wherein x is approximately 1) have been extensively utilized in
various fields of technology. Traditionally these nitrides have
been applied as hard and decorative coatings but during the past
decade they have increasingly been used as diffusion barrier and
adhesion/glue layers in microelectronic devices [Applied Surface
Science 120 (1997) 199-212]. NbCl.sub.5 for instance has been
examined as a niobium source for Atomic Layer Epitaxial growth of
NbN.sub.x, but the process required Zn as a reducing agent [Applied
Surface Science 82/83 (1994) 468-474]. NbN.sub.x films were also
deposited by atomic layer deposition using NbCl.sub.5 and NH.sub.3.
[Thin Solid Films 491 (2005) 235-241]. The chlorine content showed
strong temperature dependence as the film deposited at 500.degree.
C. was almost chlorine free, while the chlorine content was 8 at. %
when the deposition temperature was as low as 250.degree. C. Id.
The high melting point of NbCl.sub.5 also makes this precursor
difficult to use in the vapor deposition process.
[0005] Gust et al. disclose the synthesis, structure, and
properties of niobium and tantalum imido complexes bearing
pyrazolato ligands and their potential use for the growth of
tantalum nitride films by CVD. Polyhedron 20 (2001) 805-813.
[0006] Elorriaga et al. disclose asymmetric niobium guanidinates as
intermediates in the catalytic guanylation of amines (Dalton
Transactions, 2013, Vol. 42, Issue 23 pp. 8223-8230).
[0007] Tomson et al. disclose the synthesis and reactivity of the
cationic Nb and Ta monomethyl complexes
[(BDI)MeM(NtBu)][X](BDI=2,6-iPr.sub.2C.sub.6H.sub.3--N--C(Me)CH--C(Me)-N(-
2,6-iPr.sub.2C.sub.6H.sub.3); X=MeB(C.sub.6F.sub.5).sub.3 or
B(C.sub.6F.sub.5).sub.4) (Dalton Transactions 2011 Vol. 40, Issue
30, pp. 7718-7729).
[0008] DE102006037955 to Starck discloses tantalum- and
niobium-compounds having the formula
R.sup.4R.sup.5R.sup.6M(R.sup.1NNR.sup.2R.sup.3).sub.2, wherein M is
Ta or Nb; R.sup.1-R.sup.3.dbd.C.sub.1-12 alkyl, C.sub.5-12
cycloalkyl, C.sub.6-10 aryl, alkenyl, C.sub.1-4 triorganosilyl; and
R.sup.4-R.sup.6=halo, (cyclo)alkoxy, aryloxy, siloxy, BH.sub.4,
allyl, indenyl, benzyl, cyclopentadienyl, CH.sub.2SiMe.sub.3,
silylamido, amido, or imino.
[0009] Maestre et al. disclose the reaction of the
cyclopentadienyl-silyl-amido titanium compound with group 5 metal
monocyclopentadienyl complexes to form
NbCp(NH(CH.sub.2).sub.2--NH.sub.2)Cl.sub.3 and
NbCpCl.sub.2(N--(CH.sub.2).sub.2--N).
[0010] A need remains for developing liquid or low melting point
(<50.degree. C. at standard pressure), highly thermally stable,
Niobium-containing precursor molecules suitable for vapor phase
film deposition with controlled thickness and composition at high
temperature.
Notation and Nomenclature
[0011] Certain abbreviations, symbols, and terms are used
throughout the following description and claims, and include:
[0012] As used herein, the indefinite article "a" or "an" means one
or more.
[0013] As used herein, the terms "approximately" or "about"
mean.+-.10% of the value stated.
[0014] The standard abbreviations of the elements from the periodic
table of elements are used herein. It should be 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.).
[0015] As used herein, the term "independently" when used in the
context of describing R groups should be understood to denote that
the subject R group is not only independently selected relative to
other R groups bearing the same or different subscripts or
superscripts, but is also independently selected relative to any
additional species of that same R group. For example in the formula
MR.sup.1.sub.x (NR.sup.2R.sup.3).sub.(4-x), where x is 2 or 3, the
two or three R.sup.1 groups may, but need not be identical to each
other or to R.sup.2 or to R.sup.3.
[0016] As used herein, the term "alkyl group" refers to saturated
functional groups containing exclusively carbon and hydrogen atoms.
Further, the term "alkyl group" refers to linear, branched, or
cyclic alkyl groups. Examples of linear alkyl groups include
without limitation, methyl groups, ethyl groups, propyl groups,
butyl groups, etc. Examples of branched alkyls groups include
without limitation, tbutyl. Examples of cyclic alkyl groups include
without limitation, cyclopropyl groups, cyclopentyl groups,
cyclohexyl groups, etc.
[0017] As used herein, the abbreviation "Me" refers to a methyl
group; the abbreviation "Et" refers to an ethyl group; the
abbreviation "Pr" refers to a propyl group; the abbreviation "nPr"
refers to a "normal" or linear propyl group; the abbreviation "iPr"
refers to an isopropyl group; the abbreviation "Bu" refers to a
butyl group; the abbreviation "nBu" refers to a "normal" or linear
butyl group; the abbreviation "tBu" refers to a tert-butyl group,
also known as 1,1-dimethylethyl; the abbreviation "sBu" refers to a
sec-butyl group, also known as 1-methylpropyl; the abbreviation
"iBu" refers to an iso-butyl group, also known as 2-methylpropyl;
the abbreviation "amyl" refers to an amyl or pentyl group; the
abbreviation "tAmyl" refers to a tert-amyl group, also known as
1,1-dimethylpropyl.
[0018] As used herein, the abbreviation "TMS" refers to
trimethylsilyl (Me.sub.3Si--); the abbreviation "DMS" refers to
dimethylsilyl (Me.sub.2HSi--); the abbreviation "MMS" refers to
monomethylsilyl (MeH.sub.2Si--); the abbreviation "Py" refers to
pyridine; and the abbreviation R.sup.1, R.sup.2, R.sup.3-Pyr refers
to a pyrazolyl ligand having the following structure:
##STR00001##
[0019] Please note that the films or layers deposited, such as
niobium oxide, may be listed throughout the specification and
claims without reference to their proper stoichoimetry (i.e.,
NbO.sub.2 or Nb.sub.2O.sub.5). The layers may include pure (Nb)
layers, silicide (Nb.sub.oSi.sub.p) layers, carbide
(Nb.sub.oC.sub.p) layers, nitride (Nb.sub.kN.sub.l) layers, oxide
(Nb.sub.nO.sub.m) layers, or mixtures thereof; wherein k, l, m, n,
o, and p inclusively range from 1 to 6. For instance, niobium
silicide is Nb.sub.kSi.sub.l, where k and l each range from 0.5 to
5. Similarly, any referenced layers may also include a Silicon
oxide layer, Si.sub.nO.sub.m, wherein n ranges from 0.5 to 1.5 and
m ranges from 1.5 to 3.5. More preferably, the silicon oxide layer
is SiO.sub.2 or SiO.sub.3. The silicon oxide layer may be a silicon
oxide based dielectric material, such as organic based or silicon
oxide based low-k dielectric materials such as the Black Diamond II
or III material by Applied Materials, Inc. Alternatively, any
referenced silicon-containing layer may be pure silicon. Any
referenced layers, such as the niobium- or silicon-containing
layers, may also include dopants, such as B, C, P, As and/or
Ge.
[0020] Any and all ranges recited herein are inclusive of their
endpoints (i.e., x=1 to 4 includes x=1, x=4, and x=any number in
between), irrespective of whether the term "inclusively" is
used.
SUMMARY
[0021] Disclosed are Niobium-containing film forming compositions
comprising a precursor having the formula:
##STR00002##
wherein each R, R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5,
R.sup.6, and R.sup.7 is independently H, an alkyl group, or
R'.sub.3Si, with each R' independently being H or an alkyl group.
The disclosed Niobium containing film forming compositions may
include one or more of the following aspects: [0022] each R,
R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6, and R.sup.7
independently being selected from H, Me, Et, nPr, iPr, tBu, sBu,
iBu, nBu, tAmyl, SiMe.sub.3, SiMe.sub.2H, or SiH.sub.2Me; [0023] R
being tBu; R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 being
respectively H, H, H, H and H; R.sup.6 and R.sup.7 being
respectively iPr and iPr; [0024] R being tBu; R.sup.1, R.sup.2,
R.sup.3, R.sup.4 and R.sup.5 being respectively H, H, H, H and H;
R.sup.6 and R.sup.7 being respectively iPr and tBu; [0025] R being
tBu; R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 being
respectively H, H, H, H and H; R.sup.6 and R.sup.7 being
respectively tBu and tBu; [0026] R being tBu; R.sup.1, R.sup.2,
R.sup.3, R.sup.4 and R.sup.5 being respectively H, H, H, H and H;
R.sup.6 and R.sup.7 being respectively tAmyl and tAmyl; [0027] R
being tBu; R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 being
respectively Me, H, H, H and H; R.sup.6 and R.sup.7 being
respectively iPr and iPr; [0028] R being tBu; R.sup.1, R.sup.2,
R.sup.3, R.sup.4 and R.sup.5 being respectively Me, H, H, H and H;
R.sup.6 and R.sup.7 being respectively iPr and tBu; [0029] R being
tBu; R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 being
respectively Me, H, H, H and H; R.sup.6 and R.sup.7 being
respectively tBu and tBu; [0030] R being tBu; R.sup.1, R.sup.2,
R.sup.3, R.sup.4 and R.sup.5 being respectively Me, H, H, H and H;
R.sup.6 and R.sup.7 being respectively tAmyl and tAmyl; [0031] R
being tBu; R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 being
respectively Et, H, H, H and H; R.sup.6 and R.sup.7 being
respectively iPr and iPr; [0032] R being tBu; R.sup.1, R.sup.2,
R.sup.3, R.sup.4 and R.sup.5 being respectively Et, H, H, H and H;
R.sup.6 and R.sup.7 being respectively iPr and tBu; [0033] R being
tBu; R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 being
respectively Et, H, H, H and H; R.sup.6 and R.sup.7 being
respectively tBu and tBu; [0034] R being tBu; R.sup.1, R.sup.2,
R.sup.3, R.sup.4 and R.sup.5 being respectively Et, H, H, H and H;
R.sup.6 and R.sup.7 being respectively tAmyl and tAmyl; [0035] R
being tBu; R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 being
respectively iPr, H, H, H and H; R.sup.6 and R.sup.7 being
respectively iPr and iPr; [0036] R being tBu; R.sup.1, R.sup.2,
R.sup.3, R.sup.4 and R.sup.5 being respectively iPr, H, H, H and H;
R.sup.6 and R.sup.7 being respectively iPr and tBu; [0037] R being
tBu; R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 being
respectively iPr, H, H, H and H; R.sup.6 and R.sup.7 being
respectively tBu and tBu; [0038] R being tBu; R.sup.1, R.sup.2,
R.sup.3, R.sup.4 and R.sup.5 being respectively iPr, H, H, H and H;
R.sup.6 and R.sup.7 being respectively tAmyl and tAmyl; [0039] R
being tBu; R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 being
respectively tBu, H, H, H and H; R.sup.6 and R.sup.7 being
respectively iPr and iPr; [0040] R being tBu; R.sup.1, R.sup.2,
R.sup.3, R.sup.4 and R.sup.5 being respectively tBu, H, H, H and H;
R.sup.6 and R.sup.7 being respectively iPr and tBu; [0041] R being
tBu; R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 being
respectively tBu, H, H, H and H; R.sup.6 and R.sup.7 being
respectively tBu and tBu; [0042] R being tBu; R.sup.1, R.sup.2,
R.sup.3, R.sup.4 and R.sup.5 being respectively tBu, H, H, H and H;
R.sup.6 and R.sup.7 being respectively tAmyl and tAmyl; [0043] R
being tBu; R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 being
respectively SiMe.sub.3, H, H, H and H; R.sup.6 and R.sup.7 being
respectively iPr and iPr; [0044] R being tBu; R.sup.1, R.sup.2,
R.sup.3, R.sup.4 and R.sup.5 being respectively SiMe.sub.3, H, H, H
and H; R.sup.6 and R.sup.7 being respectively iPr and tBu; [0045] R
being tBu; R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 being
respectively SiMe.sub.3, H, H, H and H; R.sup.6 and R.sup.7 being
respectively tBu and tBu; [0046] R being tBu; R.sup.1, R.sup.2,
R.sup.3, R.sup.4 and R.sup.5 being respectively SiMe.sub.3, H, H, H
and H; R.sup.6 and R.sup.7 being respectively tAmyl and tAmyl;
[0047] R being tBu; R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5
being respectively iPr, H, iPr, H and iPr; R.sup.6 and R.sup.7
being respectively iPr and iPr; [0048] R being tBu; R.sup.1,
R.sup.2, R.sup.3, R.sup.4 and R.sup.5 being respectively iPr, H,
iPr, H and iPr; R.sup.6 and R.sup.7 being respectively iPr and tBu;
[0049] R being tBu; R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5
being respectively iPr, H, iPr, H and iPr; R.sup.6 and R.sup.7
being respectively tBu and tBu; [0050] R being tBu; R.sup.1,
R.sup.2, R.sup.3, R.sup.4 and R.sup.5 being respectively iPr, H,
iPr, H and iPr; R.sup.6 and R.sup.7 being respectively tAmyl and
tAmyl; [0051] R being Et; R.sup.1, R.sup.2, R.sup.3, R.sup.4 and
R.sup.5 being respectively H, H, H, H and H; R.sup.6 and R.sup.7
being respectively tAmyl and tAmyl; [0052] R being iPr; R.sup.1,
R.sup.2, R.sup.3, R.sup.4 and R.sup.5 being respectively H, H, H, H
and H; R.sup.6 and R.sup.7 being respectively tAmyl and tAmyl;
[0053] R being tAmyl; R.sup.1, R.sup.2, R.sup.3, R.sup.4 and
R.sup.5 being respectively H, H, H, H and H; R.sup.6 and R.sup.7
being respectively tAmyl and tAmyl; and [0054] R being SiMe.sub.3;
R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 being respectively
H, H, H, H and H; R.sup.6 and R.sup.7 being respectively tAmyl and
tAmyl.
[0055] Also disclosed are Nb-containing film forming composition
delivery devices comprising a canister having an inlet conduit and
an outlet conduit and containing any of the Nb-containing film
forming compositions disclosed above. The disclosed device may
include one or more of the following aspects: [0056] the
Nb-containing film forming composition having a total concentration
of metal contaminants of less than 10 ppmw; [0057] an end of the
inlet conduit end located above a surface of the Nb-containing film
forming composition and an end of the outlet conduit located below
the surface of the Nb-containing film forming composition; [0058]
an end of the inlet conduit end located below a surface of the
Nb-containing film forming composition and an end of the outlet
conduit located above the surface of the Nb-containing film forming
composition; [0059] further comprising a diaphragm valve on the
inlet and the outlet; [0060] the Nb-containing film forming
composition being NbCp(=NtBu)(N(tAmyl)-CH--CH--N(tAmyl)); or [0061]
the Nb-containing film forming composition being
Nb(MeCp)(=NtBu)(N(tBu(N(tBu)-CH--CH--N(tBu)).
[0062] Also disclosed are processes for the deposition of
Niobium-containing films on substrates. The Niobium-containing film
forming composition disclosed above is introduced into a reactor
having a substrate disposed therein. At least part of the precursor
is deposited onto the at least one substrate to form the Niobium
containing film. The disclosed processes may further include one or
more of the following aspects: [0063] introducing at least one
reactant into the reactor; [0064] the reactant being
plasma-treated; [0065] the reactant being remote plasma-treated;
[0066] the reactant not being plasma-treated; [0067] the reactant
being selected from the group consisting of H.sub.2, H.sub.2CO,
N.sub.2H.sub.4, NH.sub.3, SiH.sub.4, Si.sub.2H.sub.6,
Si.sub.3H.sub.8, SiH.sub.2Me.sub.2, SiH.sub.2Et.sub.2,
N(SiH.sub.3).sub.3, hydrogen radicals thereof, and mixtures
thereof; [0068] the reactant being H.sub.2; [0069] the reactant
being NH.sub.3; [0070] the reactant being selected from the group
consisting of: O.sub.2, O.sub.3, H.sub.2O, H.sub.2O.sub.2, NO,
N.sub.2O, NO.sub.2, oxygen radicals thereof, and mixtures thereof;
[0071] the reactant being H.sub.2O; [0072] the reactant being
plasma treated O.sub.2; [0073] the reactant being O.sub.3; [0074]
the Niobium containing film forming composition and the reactant
being introduced into the reactor simultaneously; [0075] the
reactor being configured for chemical vapor deposition; [0076] the
reactor being configured for plasma enhanced chemical vapor
deposition; [0077] the Niobium containing film forming composition
and the reactant being introduced into the chamber sequentially;
[0078] the reactor being configured for atomic layer deposition;
[0079] the reactor being configured for plasma enhanced atomic
layer deposition; [0080] the reactor being configured for spatial
atomic layer deposition; [0081] the Niobium containing film being a
pure Nb thin film; [0082] the Niobium containing film being
Nb.sub.kSi.sub.l, wherein each of k and l is an integer which
inclusively range from 1 to 6; [0083] the Niobium containing film
being Nb.sub.nO.sub.m, wherein each of n and m is an integer which
inclusively range from 1 to 6; [0084] the Niobium containing film
being NbO.sub.2 or Nb.sub.2O.sub.5; [0085] the Niobium containing
film being Nb.sub.oN.sub.p, wherein each of o and p is an integer
which inclusively range from 1 to 6; [0086] the Niobium containing
film being NbN; [0087] the Niobium containing film being
Nb.sub.oN.sub.pO.sub.q, wherein each of o, p and q is an integer
which inclusively range from 1 to 6; and [0088] the Niobium
containing film being NbON.
BRIEF DESCRIPTION OF THE FIGURES
[0089] 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
figures wherein:
[0090] FIG. 1 is a side view of one embodiment of the Nb-containing
film forming composition delivery device;
[0091] FIG. 2 is a side view of a second embodiment of the
Nb-containing film forming composition delivery device; and
[0092] FIG. 3 is a ThermoGravimetric Analysis (TGA) graph
demonstrating the percentage of weight loss with increasing
temperature of Niobium tButyl imido cyclopentadienyl
tAmyl-diazadienyl.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0093] Disclosed are Niobium-containing film forming compositions
comprising a precursor having the formula:
##STR00003##
wherein each R, R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5,
R.sup.6, and R.sup.7 is independently H, an alkyl group, or
R'.sub.3Si, with each R' independently being H or an alkyl group.
Each R, R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6, and
R.sup.7 may independently be selected from H, Me, Et, nPr, iPr,
tBu, sBu, iBu, nBu, tAmyl, SiMe.sub.3, SiMe.sub.2H, or
SiH.sub.2Me.
[0094] When R is tBu and R.sup.1-R.sup.5 is H, the precursor has
the formula:
##STR00004##
[0095] In this embodiment, R.sup.6 may be the same as R.sup.7. For
example, R.sup.6 and R.sup.7 may each be H, Me, Et, iPr, nPr, tBu,
tAmyl, SiMe.sub.3, SiHMe.sub.2, or SiH.sub.2Me. Alternatively,
R.sup.6 may differ from R.sup.7. For example, R.sup.6 may be iPr
and R.sup.7 may be tBu.
[0096] When R is tBu, R.sup.1 is Me, and R.sup.2-R.sup.5 is H, the
precursor has the formula:
##STR00005##
[0097] In this embodiment, R.sup.6 may be the same as R.sup.7. For
example, R.sup.6 and R.sup.7 may each be H, Me, Et, iPr, nPr, tBu,
tAmyl, SiMe.sub.3, SiHMe.sub.2, or SiH.sub.2Me. Alternatively,
R.sup.6 may differ from R.sup.7. For example, R.sup.6 may be iPr
and R.sup.7 may be tBu.
[0098] When R is tBu, R.sup.1 is Et, and R.sup.2-R.sup.5 is H, the
precursor has the formula:
##STR00006##
[0099] In this embodiment, R.sup.6 may be the same as R.sup.7. For
example, R.sup.6 and R.sup.7 may each be H, Me, Et, iPr, nPr, tBu,
tAmyl, SiMe.sub.3, SiHMe.sub.2, or SiH.sub.2Me. Alternatively,
R.sup.6 may differ from R.sup.7. For example, R.sup.6 may be iPr
and R.sup.7 may be tBu.
[0100] When R is tBu, R.sup.1 is iPr, and R.sup.2-R.sup.5 is H, the
precursor has the formula:
##STR00007##
[0101] In this embodiment, R.sup.6 may be the same as R.sup.7. For
example, R.sup.6 and R.sup.7 may each be H, Me, Et, iPr, nPr, tBu,
tAmyl, SiMe.sub.3, SiHMe.sub.2, or SiH.sub.2Me. Alternatively,
R.sup.6 may differ from R.sup.7. For example, R.sup.6 may be iPr
and R.sup.7 may be tBu.
[0102] When R and R.sup.1 are tBu and R.sup.2-R.sup.5 is H, the
precursor has the formula:
##STR00008##
[0103] In this embodiment, R.sup.6 may be the same as R.sup.7. For
example, R.sup.6 and R.sup.7 may each be H, Me, Et, iPr, nPr, tBu,
tAmyl, SiMe.sub.3, SiHMe.sub.2, or SiH.sub.2Me. Alternatively,
R.sup.6 may differ from R.sup.7. For example, R.sup.6 may be iPr
and R.sup.7 may be tBu.
[0104] When R is tBu, R.sup.1 is SiMe.sub.3, and R.sup.2-R.sup.5 is
H, the precursor has the formula:
##STR00009##
[0105] In this embodiment, R.sup.6 may be the same as RI. For
example, R.sup.6 and R.sup.7 may each be H, Me, Et, iPr, nPr, tBu,
tAmyl, SiMe.sub.3, SiHMe.sub.2, or SiH.sub.2Me. Alternatively,
R.sup.6 may differ from R.sup.7. For example, R.sup.6 may be iPr
and R.sup.7 may be tBu.
[0106] When R is tBu; R.sup.1, R.sup.3, and R.sup.5 are iPr; and
R.sup.2 and R.sup.4 are H, the precursor has the formula:
##STR00010##
[0107] In this embodiment, R.sup.6 may be the same as R.sup.7. For
example, R.sup.6 and R.sup.7 may each be H, Me, Et, iPr, nPr, tBu,
tAmyl, SiMe.sub.3, SiHMe.sub.2, or SiH.sub.2Me. Alternatively,
R.sup.6 may differ from R.sup.7. For example, R.sup.6 may be iPr
and R.sup.7 may be tBu.
[0108] When R.sup.1-- R.sup.5 are H and R.sup.6 and R.sup.7 are
tAmyl, the precursor has the formula:
##STR00011##
[0109] In this embodiment, R may be Et, iPr, tAmyl, or
SiMe.sub.3.
[0110] These precursors may be synthesized by reacting 1 molar
equivalent of Nb(=NtBu)Cl.sub.3(py).sub.2 with 1 molar equivalent
of the relevant alkaline cyclopentadienyl ligand (i.e., Li or Na or
K Cp) in a polar solvent at room temperature.
Nb(=NtBu)Cl.sub.3(py).sub.2 can be prepared as described in Dalton
Trans., 2011, 40, 413-420. Suitable polar solvents include
tetrahydrofuran (THF). After stirring for a sufficient period of
time, 1 molar equivalent of the freshly prepared alkaline
diazadienyl ligand at -78.degree. C. may be added. After additional
stirring at room temperature, the solvent is removed under vacuum
and the product extracted using a nonpolar solvent, such as
pentane.
[0111] 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
the purity may be determined by H NMR or gas or liquid
chromatography with mass spectrometry. The disclosed
Niobium-containing film forming compositions may contain any of the
following impurities: diazadiene; cyclopentadiene, pyridines;
alkylamines; alkylimines; THF; ether; pentane; cyclohexane;
heptanes; benzene; toluene; chlorinated metal compounds; lithium,
sodium, or potassium cyclopentadienyl or lithium, sodium, or
potassium diazadienyl. The total quantity 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
recrystallisation, sublimation, distillation, and/or passing the
gas or liquid through a suitable adsorbent, such as a 4A molecular
sieve.
[0112] Purification of the disclosed Niobium-containing film
forming composition may also result in metal impurities at the 0
ppbw to 1 ppmw, preferably 0-500 ppbw (part per billion weight)
level. These metal 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).
[0113] The Nb-containing film forming composition that have a low
melting point (i.e., melt at a temperature below 50.degree. C.)
and/or exhibit low residue (i.e., between 0% and 10%) during
thermogravimetric analysis are expected to be suitable for vapor
deposition processes.
[0114] The disclosed Nb-containing film forming compositions may be
delivered to a semiconductor processing tool by the disclosed
Nb-containing film forming composition delivery devices. FIGS. 1
and 2 show two embodiments of the disclosed delivery devices 1.
[0115] FIG. 1 is a side view of one embodiment of the Nb-containing
film forming composition delivery device 1. In FIG. 1, the
disclosed Nb-containing film forming composition 10 are contained
within a container 20 having two conduits, an inlet conduit 30 and
an outlet conduit 40. One of ordinary skill in the precursor art
will recognize that the container 20, inlet conduit 30, and outlet
conduit 40 are manufactured to prevent the escape of the gaseous
form of the Nb-containing film forming composition 10, even at
elevated temperature and pressure.
[0116] Suitable valves include spring-loaded or tied diaphragm
valves. The valve may further comprise a restrictive flow orifice
(RFO). The delivery device should be connected to a gas manifold
and in an enclosure. The gas manifold should permit the safe
evacuation and purging of the piping that may be exposed to air
when the delivery device is replaced so that any residual amounts
of the material do not react. The enclosure should be equipped with
sensors and fire control capability to control the fire in the case
of a pyrophoric material release. The gas manifold should also be
equipped with isolation valves, vacuum generators, and permit the
introduction of a purge gas at a minimum.
[0117] The delivery device must be leak tight and be equipped with
valves that do not permit escape of even minute amounts of the
material. The delivery device fluidly connects to other components
of the semiconductor processing tool, such as the gas cabinet
disclosed above, via valves 35 and 45. Preferably, the delivery
device 20, inlet conduit 30, valve 35, outlet conduit 40, and valve
45 are made of 316L EP or 304 stainless steel. However, one of
ordinary skill in the art will recognize that other inert
materials, such as Hastelloy or Inconel, may also be used in the
teachings herein to prevent any potential contamination of the
Nb-containing film forming composition 10.
[0118] In FIG. 1, the end 31 of inlet conduit 30 is located above
the surface of the Nb-containing film forming composition 10,
whereas the end 41 of the outlet conduit 40 is located below the
surface of the Nb-containing film forming composition 10. In this
embodiment, the Nb-containing film forming composition 10 is
preferably in liquid form. An inert gas, including but not limited
to nitrogen, argon, helium, and mixtures thereof, may be introduced
into the inlet conduit 30. The inert gas pressurizes the delivery
device 20 so that the liquid Nb-containing film forming composition
10 is forced through the outlet conduit 40 and to components in the
semiconductor processing tool (not shown). The semiconductor
processing tool may include a vaporizer which transforms the liquid
Nb-containing film forming composition 10 into a vapor, with or
without the use of a carrier gas such as helium, argon, nitrogen or
mixtures thereof, in order to deliver the vapor to a chamber where
a wafer to be repaired is located and treatment occurs in the vapor
phase. Alternatively, the liquid Nb-containing film forming
composition 10 may be delivered directly to the wafer surface as a
jet or aerosol.
[0119] FIG. 2 is a side view of a second embodiment of the
Nb-containing film forming composition delivery device 1. In FIG.
2, the end 31 of inlet conduit 30 is located below the surface of
the Nb-containing film forming composition 10, whereas the end 41
of the outlet conduit 40 is located above the surface of the
Nb-containing film forming composition 10. FIG. 2 also includes an
optional heating element 25, which may increase the temperature of
the Nb-containing film forming composition 10. The Nb-containing
film forming composition 10 may be in solid or liquid form. An
inert gas, including but not limited to nitrogen, argon, helium,
and mixtures thereof, is introduced into the inlet conduit 30. The
inert gas flows through the Nb-containing film forming composition
10 and carries a mixture of the inert gas and vaporized
Nb-containing film forming composition 10 to the outlet conduit 40
and to the components in the semiconductor processing tool.
[0120] Both FIGS. 1 and 2 include valves 35 and 45. One of ordinary
skill in the art will recognize that valves 35 and 45 may be placed
in an open or closed position to allow flow through conduits 30 and
40, respectively. Either delivery device 1 in FIG. 1 or 2, or a
simpler delivery device having a single conduit terminating above
the surface of any solid or liquid present, may be used if the
Nb-containing film forming composition 10 is in vapor form or if
sufficient vapor pressure is present above the solid/liquid phase.
In this case, the Nb-containing film forming composition 10 is
delivered in vapor form through the conduit 30 or 40 simply by
opening the valve 35 in FIG. 1 or 45 in FIG. 2, respectively. The
delivery device 1 may be maintained at a suitable temperature to
provide sufficient vapor pressure for the Nb-containing film
forming composition 10 to be delivered in vapor form, for example
by the use of an optional heating element 25.
[0121] While FIGS. 1 and 2 disclose two embodiments of the
Nb-containing film forming composition delivery device 1, one of
ordinary skill in the art will recognize that the inlet conduit 30
and outlet conduit 40 may both be located above or below the
surface of the Nb-containing film forming composition 10 without
departing from the disclosure herein. Furthermore, inlet conduit 30
may be a filling port. Finally, one of ordinary skill in the art
will recognize that the disclosed Nb-containing film forming
compositions may be delivered to semiconductor processing tools
using other delivery devices, such as the ampoules disclosed in WO
2006/059187 to Jurcik et al., without departing from the teachings
herein.
[0122] Also disclosed are methods for forming Niobium-containing
layers on a substrate using a vapor deposition process. The method
may be useful in the manufacture of semiconductor, photovoltaic,
LCD-TFT, or flat panel type devices.
[0123] The disclosed Niobium-containing film forming compositions
may be used to deposit Niobium-containing films using any
deposition methods known to those of skill 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, in which a hot wire serves as an energy source for the
deposition process), radicals incorporated CVD, and combinations
thereof. Exemplary ALD methods include thermal ALD, plasma enhanced
ALD (PEALD), spatial isolation ALD, hot-wire ALD (HWALD), radicals
incorporated ALD, and combinations thereof. Super critical 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.
[0124] The disclosed Niobium-containing film forming compositions
may consist of the precursor or a combination of the precursor and
a suitable solvent, such as ethyl benzene, xylene, mesitylene,
decalin, decane, dodecane, and mixtures thereof. The disclosed
precursors may be present in varying concentrations in the
solvent.
[0125] The Niobium-containing film forming compositions are
introduced into a reactor in vapor form by conventional means, such
as tubing and/or flow meters. The vapor form may be produced by
vaporizing the composition through a conventional vaporization step
such as direct vaporization, distillation, or by bubbling, or by
using a sublimator such as the one disclosed in PCT Publication
WO2009/087609 to Xu et al. The composition may be fed in liquid
state to a vaporizer where it is vaporized before it is introduced
into the reactor. Alternatively, the composition may be vaporized
by passing a carrier gas into a container containing the
composition or by bubbling the carrier gas into the composition.
The carrier gas may include, but is not limited to, Ar, He,
N.sub.2, and mixtures thereof. Bubbling with a carrier gas may also
remove any dissolved oxygen present in the composition. The carrier
gas and composition are then introduced into the reactor as a
vapor.
[0126] If necessary, the container containing the disclosed
composition may be heated to a temperature that permits the
composition to be in its liquid phase and to have a sufficient
vapor pressure. The container may be maintained at temperatures in
the range of, for example, approximately 0.degree. C. to
approximately 150.degree. C. Those skilled in the art recognize
that the temperature of the container may be adjusted in a known
manner to control the amount of precursor vaporized.
[0127] The reactor may be any enclosure or chamber within a device
in which deposition methods take place such as without limitation,
a parallel-plate type reactor, a cold-wall type reactor, a hot-wall
type reactor, a single-wafer reactor, a multi-wafer reactor, or
other types of deposition systems under conditions suitable to
cause the compounds to react and form the layers. One of ordinary
skill in the art will recognize that any of these reactors may be
used for either ALD or CVD deposition processes.
[0128] The reactor contains one or more substrates onto which the
films will be deposited. A substrate is generally defined as the
material on which a process is conducted. The substrates may be any
suitable substrate used in semiconductor, photovoltaic, flat panel,
or LCD-TFT device manufacturing. Examples of suitable substrates
include wafers, such as silicon, silica, glass, plastic or GaAs
wafers. The wafer may have one or more layers of differing
materials deposited on it from a previous manufacturing step. For
example, the wafers may include silicon layers (crystalline,
amorphous, porous, etc.), silicon oxide layers, silicon nitride
layers, silicon oxy nitride layers, carbon doped silicon oxide
(SiCOH) layers, or combinations thereof. Additionally, the wafers
may include copper layers or noble metal layers (e.g. platinum,
palladium, rhodium, or gold). The wafers may include barrier
layers, such as manganese, manganese oxide, etc. Plastic layers,
such as poly(3,4-ethylenedioxythiophene)poly(styrenesulfonate)
[PEDOT:PSS] may also be used. The layers may be planar or
patterned. The disclosed processes may deposit the
Niobium-containing layer directly on the wafer or directly on one
or more than one (when patterned layers form the substrate) of the
layers on top of the wafer. Furthermore, one of ordinary skill in
the art will recognize that the terms "film" or "layer" used herein
refer to a thickness of some material laid on or spread over a
surface and that the surface may be a trench or a line. Throughout
the specification and claims, the wafer and any associated layers
thereon are referred to as substrates. For example, a Niobium
Nitride film may be deposited onto a Si layer. In subsequent
processing, a zirconium oxide layer may be deposited on the Niobium
Nitride layer, a second Niobium Nitride layer may be deposited on
the zirconium oxide layer forming a NbN/ZrO.sub.2/NbN stack used in
DRAM capacitors.
[0129] The temperature and the pressure within the reactor are held
at conditions suitable for vapor depositions. In other words, after
introduction of the vaporized composition into the chamber,
conditions within the chamber are such that at least part of the
precursor is deposited onto the substrate to form a
Niobium-containing film. For instance, the pressure in the reactor
may be held between about 1 Pa and about 10.sup.5 Pa, more
preferably between about 25 Pa and about 10.sup.3 Pa, as required
per the deposition parameters. Likewise, the temperature in the
reactor may be held between about 100.degree. C. and about
500.degree. C., preferably between about 150.degree. C. and about
400.degree. C. One of ordinary skill in the art will recognize that
"at least part of the precursor is deposited" means that some or
all of the precursor reacts with or adheres to the substrate.
[0130] The temperature of the reactor may be controlled by either
controlling the temperature of the substrate holder or controlling
the temperature of the reactor wall. Devices used to heat the
substrate are known in the art. The reactor wall is heated to a
sufficient temperature to obtain the desired film at a sufficient
growth rate and with desired physical state and composition. A
non-limiting exemplary temperature range to which the reactor wall
may be heated includes from approximately 100.degree. C. to
approximately 500.degree. C. When a plasma deposition process is
utilized, the deposition temperature may range from approximately
150.degree. C. to approximately 400.degree. C. Alternatively, when
a thermal process is performed, the deposition temperature may
range from approximately 200.degree. C. to approximately
500.degree. C.
[0131] In addition to the disclosed Niobium-containing film forming
composition, a reactant may be introduced into the reactor. The
reactant may be H.sub.2, H.sub.2CO, N.sub.2H.sub.4, NH.sub.3,
SiH.sub.4, Si.sub.2H.sub.6, Si.sub.3H.sub.8, SiH.sub.2Me.sub.2,
SiH.sub.2Et.sub.2, N(SiH.sub.3).sub.3, hydrogen radicals thereof,
and mixtures thereof. Preferably, the reactant is H.sub.2 or
NH.sub.3.
[0132] Alternatively, the reactant may be an oxidizing gas such as
one of O.sub.2, O.sub.3, H.sub.2O, H.sub.2O.sub.2, NO, N.sub.2O,
NO.sub.2, oxygen containing radicals such as O.sup.- or OH.sup.-,
carboxylic acids, formic acid, acetic acid, propionic acid, and
mixtures thereof. Preferably, the oxidizing gas is selected from
the group consisting of O.sub.2, O.sub.3, or H.sub.2O.
[0133] The reactant may be treated by a plasma, in order to
decompose the reactant into its radical form. N.sub.2 may also be
utilized as a nitrogen source gas when treated with plasma. For
instance, the plasma may be generated with a power ranging from
about 50 W to about 500 W, preferably from about 100 W to about 400
W. The plasma may be generated or present within the reactor
itself. Alternatively, the plasma may generally be at a location
removed from the reactor, for instance, in a remotely located
plasma system. One of skill in the art will recognize methods and
apparatus suitable for such plasma treatment.
[0134] For example, the reactant may be introduced into a direct
plasma reactor, which generates plasma in the reaction chamber, to
produce the plasma-treated reactant in the reaction chamber.
Exemplary direct plasma reactors include the Titan.TM. PECVD System
produced by Trion Technologies. The reactant may be introduced and
held in the reaction chamber prior to plasma processing.
Alternatively, the plasma processing may occur simultaneously with
the introduction of the reactant. In-situ plasma is typically a
13.56 MHz RF inductively coupled plasma that is generated between
the showerhead and the substrate holder. The substrate or the
showerhead may be the powered electrode depending on whether
positive ion impact occurs. Typical applied powers in in-situ
plasma generators are from approximately 30 W to approximately 1000
W. Preferably, powers from approximately 30 W to approximately 600
W are used in the disclosed methods. More preferably, the powers
range from approximately 100 W to approximately 500 W. The
disassociation of the reactant using in-situ plasma is typically
less than achieved using a remote plasma source for the same power
input and is therefore not as efficient in reactant disassociation
as a remote plasma system, which may be beneficial for the
deposition of Niobium-containing films on substrates easily damaged
by plasma.
[0135] Alternatively, the plasma-treated reactant may be produced
outside of the reaction chamber. The MKS Instruments' ASTRONi.RTM.
reactive gas generator may be used to treat the reactant prior to
passage into the reaction chamber. Operated at 2.45 GHz, 7 kW
plasma power, and a pressure ranging from approximately 0.5 Torr to
approximately 10 Torr, the reactant O.sub.2 may be decomposed into
two O.sup.- radicals. Preferably, the remote plasma may be
generated with a power ranging from about 1 kW to about 10 kW, more
preferably from about 2.5 kW to about 7.5 kW.
[0136] The vapor deposition conditions within the chamber allow the
disclosed composition and the reactant to react and form a
Niobium-containing film on the substrate. In some embodiments,
Applicants believe that plasma-treating the reactant may provide
the reactant with the energy needed to react with the disclosed
precursors.
[0137] Depending on what type of film is desired to be deposited,
an additional precursor compound may be introduced into the
reactor. The additional precursor may 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), zirconium, germanium,
silicon, magnesium, titanium, manganese, ruthenium, bismuth, lead,
magnesium, aluminum, or mixtures of these. When an additional
precursor compound is utilized, the resultant film deposited on the
substrate contains the Niobium metal in combination with an
additional element.
[0138] The Niobium-containing film forming composition and
reactants may be introduced into the reactor either simultaneously
(chemical vapor deposition), sequentially (atomic layer deposition)
or different combinations thereof. The reactor may be purged with
an inert gas between the introduction of the compositions and the
introduction of the reactants. Alternatively, the reactants and the
compositions may be mixed together to form a reactant/composition
mixture, and then introduced to the reactor in mixture form.
Another example is to introduce the reactant continuously and to
introduce the Niobium-containing film forming composition by pulse
(pulsed chemical vapor deposition).
[0139] The vaporized composition and the reactant may be pulsed
sequentially or simultaneously (e.g. pulsed CVD) into the reactor.
Each pulse of composition may last for a time period ranging from
about 0.01 seconds to about 10 seconds, alternatively from about
0.3 seconds to about 3 seconds, alternatively from about 0.5
seconds to about 2 seconds. In another embodiment, the reactant may
also be pulsed into the reactor. In such embodiments, the pulse of
each may last for a time period ranging from about 0.01 seconds to
about 10 seconds, alternatively from about 0.3 seconds to about 3
seconds, alternatively from about 0.5 seconds to about 2 seconds.
In another alternative, the vaporized compositions and reactants
may be simultaneously sprayed from a shower head under which a
susceptor holding several wafers is spun (spatial ALD).
[0140] Depending on the particular process parameters, deposition
may take place for a varying length of time. Generally, deposition
may be allowed to continue as long as desired or necessary to
produce a film with the necessary properties. Typical film
thicknesses may vary from several angstroms to several hundreds of
microns, depending on the specific deposition process. The
deposition process may also be performed as many times as necessary
to obtain the desired film.
[0141] In one non-limiting exemplary CVD process, the vapor phase
of the disclosed Niobium-containing film forming composition and a
reactant are simultaneously introduced into the reactor. The two
react to form the resulting Niobium-containing film. When the
reactant in this exemplary CVD process is treated with a plasma,
the exemplary CVD process becomes an exemplary PECVD process. The
reactant may be treated with plasma prior or subsequent to
introduction into the chamber.
[0142] In one non-limiting exemplary ALD process, the vapor phase
of the disclosed Niobium-containing film forming composition is
introduced into the 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. A reactant (for example,
NH.sub.3) is introduced into the reactor where it reacts with the
absorbed composition in a self-limiting manner. Any excess reactant
is removed from the reactor by purging and/or evacuating the
reactor. If the desired film is a Niobium Nitride, this two-step
process may provide the desired film thickness or may be repeated
until a film having the necessary thickness has been obtained.
[0143] Alternatively, if the desired film contains the Niobium
transition metal and a second element, the two-step process above
may be followed by introduction of the vapor of an additional
precursor compound into the reactor. The additional precursor
compound will be selected based on the nature of the
Niobium-containing film being deposited. 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. Once again, a
reactant may be introduced into the reactor to react with the
precursor compound. Excess reactant is removed from the reactor by
purging and/or evacuating the reactor. If a desired film thickness
has been achieved, the process may 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 compound, and
reactant, a film of desired composition and thickness can be
deposited.
[0144] When the reactant in this exemplary ALD process is treated
with a plasma, the exemplary ALD process becomes an exemplary PEALD
process. The reactant may be treated with plasma prior or
subsequent to introduction into the chamber.
[0145] In a second non-limiting exemplary ALD process, the vapor
phase of one of the disclosed Niobium-containing film forming
composition, for example Niobium (tbutyl imido)
tris(3,5-diisopropylpyrazolyl) (Nb(=NtBu)(iPr, H, iPr-Pyr).sub.3),
is introduced into the reactor, where it is contacted with a Si
substrate. Excess composition may then be removed from the reactor
by purging and/or evacuating the reactor. A reactant (for example,
NH.sub.3) is introduced into the reactor where it reacts with the
absorbed composition in a self-limiting manner to form a Niobium
Nitride film. Any excess NH.sub.3 gas is removed from the reactor
by purging and/or evacuating the reactor. These two steps may be
repeated until the Niobium Nitride film obtains a desired
thickness, typically around 10 angstroms. ZrO.sub.2 may then be
deposited on the NbN film. For example, ZrCp(NMe.sub.2).sub.3 may
serve as the Zr precursor. The second non-limiting exemplary ALD
process described above using Nb(=NtBu)(iPr,H,iPr-Pyr).sub.3 and
NH.sub.3 may then be repeated on the ZrO.sub.2 layer. The resulting
NbN/ZrO.sub.2/NbN stack may be used in DRAM capacitors.
[0146] In a third non-limiting exemplary ALD process, the vapor
phase of one of the disclosed Niobium-containing film forming
composition, for example Niobium tButyl imido cyclopentadienyl
tAmyl-diazadienyl (Nb(=NtBu)Cp(.about.N(tAmyl)-CH--CH--N(tAmyl))),
is introduced into the reactor, where it is contacted with a Si
substrate.
[0147] Excess composition may then be removed from the reactor by
purging and/or evacuating the reactor. A reactant (for example,
NH.sub.3) is introduced into the reactor where it reacts with the
absorbed composition in a self-limiting manner to form a Niobium
Nitride film. Any excess NH.sub.3 gas is removed from the reactor
by purging and/or evacuating the reactor. These two steps may be
repeated until the Niobium Nitride film obtains a desired
thickness, typically around 10 angstroms. ZrO.sub.2 may then be
deposited on the NbN film. For example, ZrCp(NMe.sub.2).sub.3 may
serve as the Zr precursor. The third non-limiting exemplary ALD
process described above using
(Nb(=NtBu)Cp(.about.N(tAmyl)-CH--CH--N(tAmyl))) and NH.sub.3 may
then be repeated on the ZrO.sub.2 layer. The resulting
NbN/ZrO.sub.2/NbN stack may be used in DRAM capacitors.
[0148] The Niobium-containing films resulting from the processes
discussed above may include Nb, Nb.sub.kSi.sub.l, Nb.sub.nO.sub.m,
Nb.sub.oN.sub.p, or Nb.sub.oN.sub.pO.sub.q, wherein k, l, m, n, o,
p, and q may each independently range from 1 to 6. Exemplary films
include NbO.sub.2, Nb.sub.2O.sub.5, NbN, and NbON. One of ordinary
skill in the art will recognize that by judicial selection of the
appropriate organosilane precursor and reactants, the desired film
composition may be obtained.
[0149] Upon obtaining a desired film thickness, the film may be
subject to further processing, such as thermal annealing,
furnace-annealing, rapid thermal annealing, UV or e-beam curing,
and/or plasma gas exposure. Those skilled in the art recognize the
systems and methods utilized to perform these additional processing
steps. For example, the NbN film may be exposed to a temperature
ranging from approximately 200.degree. C. and approximately
1000.degree. C. for a time ranging from approximately 0.1 second to
approximately 7200 seconds under an inert atmosphere, a
N-containing atmosphere, or combinations thereof. Most preferably,
the temperature is 400.degree. C. for 3600 seconds under an inert
atmosphere or a N-containing atmosphere. The resulting film may
contain fewer impurities and therefore may have an 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/flash annealing
process being performed in a separate apparatus. Any of the above
post-treatment methods, but especially thermal annealing, has been
found effective to reduce carbon contamination of the NbN film.
This in turn tends to improve the resistivity of the film.
[0150] After annealing, the Niobium-containing films deposited by
any of the disclosed processes may have a bulk resistivity at room
temperature of approximately 50 .mu.ohmcm to approximately 1,000
.mu.ohmcm. Room temperature is approximately 20.degree. C. to
approximately 28.degree. C. depending on the season. Bulk
resistivity is also known as volume resistivity. One of ordinary
skill in the art will recognize that the bulk resistivity is
measured at room temperature on NbN films that are typically
approximately 50 nm thick. The bulk resistivity typically increases
for thinner films due to changes in the electron transport
mechanism. The bulk resistivity also increases at higher
temperatures.
[0151] In another alternative, the disclosed compositions may be
used as doping or implantation agents. Part of the disclosed
composition may be deposited on top of the film to be doped, such
as an indium oxide (In.sub.2O.sub.3) film, tantalum dioxide
(TaO.sub.2), vanadium dioxide (VO.sub.2) film, a titanium oxide
film, a copper oxide film, or a tin dioxide (SnO.sub.2) film. The
Niobium then diffuses into the film during an annealing step to
form the Niobium-doped films {(Nb)In.sub.2O.sub.3, (Nb)VO.sub.2,
(Nb)TiO, (Nb)CuO, (Nb)SnO.sub.2}. See, e.g., US2008/0241575 to
Lavoie et al., the doping method of which is incorporated herein by
reference in its entirety. Alternatively, high energy ion
implantation using a variable energy radio frequency quadrupole
implanter may be used to dope the Niobium of the disclosed
compositions into a film. See, e.g., Kensuke et al., JVSTA 16(2)
March/April 1998, the implantation method of which is incorporated
herein by reference in its entirety. In another alternative, plasma
doping, pulsed plasma doping or plasma immersion ion implantation
may be performed using the disclosed compounds. See, e.g., Felch et
al., Plasma doping for the fabrication of ultra-shallow junctions
Surface Coatings Technology, 156 (1-3) 2002, pp. 229-236, the
doping method of which is incorporated herein by reference in its
entirety.
EXAMPLE
[0152] The following non-limiting example is provided to further
illustrate embodiments of the invention. However, the examples are
not intended to be all inclusive and are not intended to limit the
scope of the inventions described herein.
EXAMPLE
Synthesis of Niobium tButyl Imido Cyclopentadienyl
tAmyl-Diazadienyl
[0153] To a solution of Nb(=NtBu)Cl.sub.3(py).sub.2 (2 g, 4.6 mmol)
in 30 mL of THF at -78.degree. C., was added dropwise a solution of
Sodium Cyclopendienyl (2.4 mL, 2.0M, 4.8 mmol). The mixture was
stirred room temperature for 12 h. Color turned to yellow. A fresh
red solution of lithium tAmyl-Diazadienyl in THF, prepared from the
reaction of tAmyl-Diazadiene (0.9 g, 4.6 mmol) and pure Lithium (80
mg, 11.5 mmol), was added at -78.degree. C. and the mixture turned
to dark brown. After stirring overnight at room temperature, the
solvent was removed under vacuum and the product was extracted with
pentane to give brown oil. The material was then purified by
distillation up to 220.degree. C. @25 mTorr to give 0.23 g (11%) of
brown oil. The material was characterized by NMR .sup.1H (.delta.,
ppm, C.sub.6D.sub.6): 5.68 (s, 5H), 5.65 (s, 2H), 1.60 (m, 4H),
1.29 (s, 12H), 1.26 (s, 9H), 1.28 (t, 6H).
[0154] The solid left a 1.6% residual mass during Open-Cup TGA
analysis measured at a temperature rising rate of 10.degree. C./min
in an atmosphere which flows nitrogen at 200 mL/min. These results
are shown in FIG. 3, which is a TGA graph illustrating the
percentage of weight loss upon temperature increase.
[0155] 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 the invention, may be made by those skilled in the art
within the principle and scope of the invention as expressed in the
appended claims. Thus, the present invention is not intended to be
limited to the specific embodiments in the examples given above
and/or the attached drawings.
* * * * *