U.S. patent application number 09/791409 was filed with the patent office on 2002-01-31 for volatile precursors for deposition of metals and metal-containing films.
Invention is credited to Farnia, Morteza, Norman, John Anthony Thomas, Roberts, David Allen.
Application Number | 20020013487 09/791409 |
Document ID | / |
Family ID | 26889867 |
Filed Date | 2002-01-31 |
United States Patent
Application |
20020013487 |
Kind Code |
A1 |
Norman, John Anthony Thomas ;
et al. |
January 31, 2002 |
Volatile precursors for deposition of metals and metal-containing
films
Abstract
This invention is directed to a group of novel homologous eight
membered ring compounds having a metal, such as copper, reversibly
bound in the ring and containing carbon, nitrogen, silicon and/or
other metals. A structural representation of the compounds of this
invention is shown below: 1 wherein M and M' are each a metal such
as Cu, Ag, Au and Ir; X and X' can be N or O; Y and Y' can be Si,
C; Sn, Ge, or B; and Z and Z' can be C, N, or O. Substituents
represented by R1, R2, R3, R4, R5, R6, R1', R2', R3', R4', R5', and
R6' will vary depending on the ring atom to which they are
attached. This invention is also directed to depositing metal and
metal-containing films on a substrate, under ALD or CVD conditions,
using the above novel compounds as precursors.
Inventors: |
Norman, John Anthony Thomas;
(Encinitas, CA) ; Roberts, David Allen;
(Encinitas, CA) ; Farnia, Morteza; (Lake Forest,
CA) |
Correspondence
Address: |
AIR PRODUCTS AND CHEMICALS, INC.
PATENT DEPARTMENT
7201 HAMILTON BOULEVARD
ALLENTOWN
PA
181951501
|
Family ID: |
26889867 |
Appl. No.: |
09/791409 |
Filed: |
February 22, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60194285 |
Apr 3, 2000 |
|
|
|
Current U.S.
Class: |
556/7 ; 556/10;
556/81 |
Current CPC
Class: |
C07F 1/005 20130101;
C07F 1/08 20130101; C23C 16/45553 20130101; C07F 5/02 20130101;
C07F 7/10 20130101 |
Class at
Publication: |
556/7 ; 556/10;
556/81 |
International
Class: |
C07F 007/30; C07F
007/22 |
Claims
What is claimed is:
1. A compound represented by the structure: 4wherein M and M' are
each a metal; X and X' are each N or O; Y and Y' are each Si, C,
Sn, Ge, B, or Al; Z and Z' are each C, N, or O; R1, R2, R1', and
R2' are each independently H, an alkyl, an alkenyl, an alkynyl, a
partially fluorinated alkyl, an aryl, an alkyl-substituted aryl, a
partially fluorinated aryl, a fluoralkyl-substituted aryl, a
trialkylsiloxy, a triarylsiloxy, a trialkylsilyl; or a
triarylsilyl; R3, R4, R3', and R4' are each independently H, an
alkyl, a partially fluorinated alkyl, a trialkyl siloxy, an aryl,
an alkyl-substituted aryl, a partially fluorinated aryl, a
fluoroalkyl-substituted aryl, an alkoxy, a trialkylsiloxy, a
triarylsiloxy, a trialkylsilyl, a triarylsilyl, a
bis(trialkylsilyl)amido, a bis(triarylsilyl)amido, or a halogen;
and R5, R6, R5', and R6' are each independently H, an alkyl, an
alkenyl, an alkynyl, a partially fluorinated alkyl, an aryl, an
alkyl-substituted aryl, a partially fluorinated aryl, a
fluoralkyl-substituted aryl, a halogen, a trialkylsiloxy, a
triarylsiloxy, a trialkylsilyl, a triarylsilyl, a
trialkylsilanoate, or an alkoxy; provided that when X and `X` are
each O, there is no substitution at R6 and R6'; further provided
that when Z and Z' are each O, there is no substitution at R5, R6,
R5', or R6'; said alkyl and alkoxide having 1 to 8 carbons; said
alkenyl and alkynyl having 2 to 8 carbons; and said aryl having 6
carbons.
2. The compound of claim 1 wherein M and M' are each Cu.
3. The compound of claim 1 wherein X and X' are each N.
4. The compound of claim 3 wherein Y and Y' are each Si.
5. The compound of claim 4 wherein Z and Z' are each C.
6. A compound represented by the structure: 5wherein M and M' are
each Cu; X and X' are each N; Y and Y' are each Si; Z and Z' are
each C; R1, R2, R1', and R2' are each independently a
C.sub.1--C.sub.8 alkyl, a C.sub.1--C.sub.8 alkene, a
C.sub.1--C.sub.8 alkyne, a partially fluorinated C.sub.1--C.sub.8
alkyl, an aryl, an alkyl-substituted aryl, a partially fluorinated
aryl, or a fluoralkyl-substituted aryl; R3, R4, R3', and R4' are
each independently a C.sub.1--C.sub.8 alkyl, a partially
fluorinated C.sub.1--C.sub.8 alkyl, a trialkyl siloxy, an aryl, an
alkyl-substituted aryl, a partially fluorinated aryl, a
fluoroalkyl-substituted aryl, an alkoxy, or a halogen; and each of
R5, R6, R5', and R6' are independently H, an alkyl, an alkene, an
alkyne, a partially fluorinated C.sub.1--C.sub.8 alkyl, an aryl, an
alkyl-substituted aryl, a partially fluorinated aryl, a
fluoralkyl-substituted aryl, a halogen, a trialkylsilyl, a
triarylsilyl, a trialkylsilanoate, or an alkoxy; said alkyl and
alkoxide having 1 to 8 carbons; said alkenyl and alkynyl having 2
to 8 carbons; and said aryl having 6 carbons.
7. The compound of claim 6 wherein R1, R2, R3, R4, R1', R2', R3',
and R4' are each methyl; and R5, R6, R5', and R6' are each H.
8. The compound of claim 6 wherein R1 , R2, R3, R4, R1', R2', R3',
and R4' are each methyl; R5 and R5' are each trimethylsilyl; and R6
and R6' are each H.
9. A method of forming a metal or metal-containing film on a
substrate, under ALD conditions, comprising (a) reacting a metal
substrate, a metal containing substrate, a metalloid substrate, or
a metalloid-containing substrate surface with an appropriate
reagent to give a surface bearing hydroxyl OH or oxide oxygen; (b)
chemisorbing a layer of a composition comprising a metal complex of
structure [1] onto the surface bearing hydroxyl OH or oxide oxygen
to form a newly metal functionalized surface: 6wherein M and M' are
each a metal; X and X' are each N or O; Y and Y' are each Si, C,
Sn, Ge, B, or Al; Z and Z' are each C, N, or O; R1, R2, R1', and
R2' are each independently H, an alkyl, an alkenyl, an alkynyl, a
partially fluorinated alkyl, an aryl, an alkyl-substituted aryl, a
partially fluorinated aryl, a fluoralkyl-substituted aryl; a
trialkylsiloxy, a triarylsiloxy, a trialkylsilyl; or a
triarylsilyl; R3, R4, R3', and R4' are each independently H, an
alkyl, a partially fluorinated alkyl, a trialkyl siloxy, an aryl,
an alkyl-substituted aryl, a partially fluorinated aryl, a
fluoroalkyl-substituted aryl, an alkoxy, a trialkylsiloxy, a
triarylsiloxy, a trialkylsilyl, a triarylsilyl, a
bis(trialkylsilyl)amido, a bis(triarylsilyl)amido, or a halogen;
and R5, R6, R5', and R6' are each independently H, an alkyl, an
alkenyl, an alkynyl, a partially fluorinated alkyl, an aryl, an
alkyl-substituted aryl, a partially fluorinated aryl, a
fluoralkyl-substituted aryl, a halogen, a trialkylsiloxy, a
triarylsiloxy, a trialkylsilyl, a triarylsilyl, a
trialkylsilanoate, or an alkoxy; provided that when X and `X` are
each O, there is no substitution at R6 and R6'; further provided
that when Z and Z' are each O, there is no substitution at R5, R6,
R5', or R6'; said alkyl and alkoxide having 1 to 8 carbons; said
alkenyl and alkynyl having 2 to 8 carbons; and said aryl having 6
carbons; (c) oxidizing or hydroxylating the newly metal
functionalized surface to form a metal oxide layer; (d) repeating
the above steps (b) and (c) as needed to build a required number of
metal oxide layers for a thickness which can be chemically reduced;
and (e) reducing the metal oxide layers to form a smooth metal
film; and (f) optionally repeating steps (a) through (e) to grow a
thicker metal film.
10. The method of claim 9 wherein said substrate is silicon or
germanium.
11. The method of claim 10 wherein M and M' are selected from the
group consisting of Cu, Ag, Au, and Ir.
12. The method of claim 10 wherein M and M' are each Cu.
13. The method of claim 12 wherein X and X' are each N.
14. The method of claim 13 wherein Y and Y' are each Si.
15. The method of claim 14 wherein Z and Z' are each C.
16. The method of claim 10 wherein M and M' are different metals in
each layer when there is more than one layer.
17. The method of claim 10 wherein the composition of (b) also
comprises another metal precursor selected from the groups
consisting of a metal .beta.-diketonate; a metal alkoxide; a metal
amide; a metal bis(alkoxide); a metal bis (.beta.-ketonate); a
metal bis (.beta.-ketoimide); a metal (.beta.-diimide); and a metal
(amidinate).
18. A method of forming a metal or metal-containing film comprising
reacting, under chemical vapor deposition conditions sufficient to
deposit a film on a substrate, a precursor represented by the
structure: 7wherein M and M' are each a metal; X and X' are each N
or O; Y and Y' are each Si, C, Sn, Ge, B, or Al; Z and Z' are each
C, N, or O; R1, R2, R1, and R2' are each independently H, an alkyl,
an alkenyl, an alkynyl, a partially fluorinated alkyl, an aryl, an
alkyl-substituted aryl, a partially fluorinated aryl, a
fluoralkyl-substituted aryl; a trialkylsiloxy, a triarylsiloxy, a
trialkylsilyl, or a triarylsilyl; R3, R4, R3', and R4' are each
independently H, an alkyl, a partially fluorinated alkyl, a
trialkyl siloxy, an aryl, an alkyl-substituted aryl, a partially
fluorinated aryl, a fluoroalkyl-substituted aryl, an alkoxy, a
trialkylsiloxy, a triarylsiloxy, a trialkylsilyl, a triarylsilyl, a
bis(trialkylsilyl)amido, a bis(triarylsilyl)amido, or a halogen;
and R5, R6, R5', and R6' are each independently H, an alkyl, an
alkenyl, an alkynyl, a partially fluorinated alkyl, an aryl, an
alkyl-substituted aryl, a partially fluorinated aryl, a
fluoralkyl-substituted aryl, a halogen, a trialkylsiloxy, a
triarylsiloxy, a trialkylsilyl, a triarylsilyl, a
trialkylsilanoate, or an alkoxy; provided that when X and `X` are
each O, there is no substitution at R6 and R6'; further provided
that when Z and Z' are each O, there is no substitution at R5, R6,
R5', or R6'; said alkyl and alkoxide having 1 to 8 carbons; said
alkenyl and alkynyl having 2 to 8 carbons; and said aryl having 6
carbons.
19. The method of claim 18 wherein M and M' are selected from the
group consisting of selected from the group consisting of Cu, Ag,
Au, Os, and Ir.
20. The method of claim 18 wherein M and M' are each Cu.
21. The method of claim 20 wherein X and X' are each N.
22. The method of claim 21 wherein Y and Y' are each Si.
23. The method of claim 22 wherein Z and Z' are each C.
24. The method of claim 18 wherein M and M' are each Pt, Pd, Rh, or
Ru.
Description
BACKGROUND OF THE INVENTION
[0001] The semiconductor industry is now using copper interconnects
in state of the art microprocessors. These embedded fine metal
lines form the three dimensional grid upon which millions of
transistors at the heart of the microprocessor can communicate and
perform complex calculations. Copper is chosen over the more
conventionally used aluminum since it is a superior electrical
conductor thereby providing higher speed interconnections of
greater current carrying capability. These interconnect pathways
are prepared by the damascene process whereby photolithographically
patterned and etched trenches (and vias) in the dielectric
insulator are coated with a conformal thin layer of a diffusion
barrier material (for copper this is usually tantalum or tantalum
nitride) and then completely filling in the features with pure
copper. Excess copper is then removed by the process of chemical
mechanical polishing. Since the smallest features to be filled can
be less than 0.2 microns wide and over 1 micron deep, it is crucial
that the copper metallization technique used is capable of evenly
filling these deeply etched features without leaving any voids
which could lead to electrical failures in the finished product.
Copper chemical vapor deposition (CVD) is a technique that is well
known for its ability to `gap fill` such structures. In this
process, a vapor of a volatile organometallic species containing
copper is introduced to the surface to be metallized, whereupon a
chemical reaction occurs in which only copper is deposited on the
surface. Since the copper is delivered in a vapor form it evenly
accesses both vertical and horizontal surfaces to yield a very
evenly distributed film. Many precursors for copper CVD are known.
The most desirable are those that are highly volatile, give pure
copper films and do not introduce contaminating species into the
reaction chamber or onto diffusion barrier surfaces. Currently, the
biggest challenge facing copper CVD is its poor adhesion to
tantalum-based diffusion barriers leading to delamination of the
copper film during chemical mechanical polishing.
[0002] CVD copper precursors can be grouped into the following
three major categories:
[0003] 1. CVD copper using Cu(hfac)L type precursors where
(hfac)represents 1,1,1,5,5,5-hexafluoro-2,4-pentanedionate anion
and (L)represents a neutral stabilizing ligand, usually an olefin
an alkyne or a trialkylphosphine.
[0004] Many of these compounds are volatile liquids, the most well
known being the compound Cu(hfac)tmvs, where tmvs is
trimethylvinylsilane, known commercially as CupraSelect.RTM.,
available from Schumacher unit of Air Products and Chemicals, Inc.,
and described in U.S. Pat. No. 5,144,049. This class of precursors
function by a process of disproportionation, whereby two molecules
of Cu(hfac)L react together on a heated substrate surface to give
copper metal, two molecules of free ligand (L) and the volatile
by-product Cu(hfac).sub.2. This is shown below in Equation (a):
2 Cu(hfac)L.fwdarw.Cu+Cu(hfac).sub.2+2L (a)
[0005] This process is typically run at around 200.degree. C. Note
that in this process one half of the copper from the initial
precursor cannot be utilized since it constitutes part of the
Cu(hfac).sub.2 by-product. One potential drawback of these
precursors is their tendency to chemically degrade upon contact
with tantalum or tantalum nitride diffusion barrier surfaces before
the CVD copper film can begin to form. The chemical cause of this
adverse reaction is thought to stem from the fluorocarbon character
of the `hfac` portion of the copper precursor rendering it reactive
with tantalum. This degradation leads to a thin layer of chemical
debris forming between the tantalum and copper. The lack of direct
contact between the tantalum and copper is thought to cause three
main effects. First, the mechanical adhesion between the two metals
is compromised, resulting in their tendency for copper to
delaminate under conditions of chemical mechanical polishing.
Secondly, the chemical debris tends to act as an electrical
insulator, resulting in poor electrical contact between the copper
and the tantalum. Thirdly, since the copper is not growing directly
onto the tantalum, it cannot replicate its crystal orientation, and
hence, grows as a randomly oriented film (R. Kroger et al, Journal
of the Electrochemical Society, Vol.146, (9), pages 3248-3254
(1999)).
[0006] 2. CVD copper from Cu.sup.+2(X).sub.2
[0007] These compounds typically do not give pure copper films by
CVD unless a chemical reducing agent, such as hydrogen, is used in
the CVD processing, as shown below in Equation (b):
Cu(X).sub.2+H.sub.2.fwdarw.Cu+2XH (b)
[0008] Examples of this type of precursor include; Cu.sup.+2
bis(.beta.-diketonates) (Wong, V., et al, Materials Research
Society Symp Proc, Pittsburgh, Pa., 1990, pages 351-57; Awaya, N.,
Journal of Electronic Materials, Vol 21, No 10, pages
959-964,1992), Cu+.sup.2 bis(.beta.-diimine) and Cu.sup.+2
bis(.beta.-ketoimine) compounds (U.S. Pat. No. 3,356,527, Fine, S.
M., Mater. Res. Soc. Symp. Proc., 1990, pages 204, 415). These
copper.sup.(+2) compounds are typically solids, and the CVD
processing temperatures for them are typically above 200.degree. C.
If these precursors are substantially fluorinated, then similar
problems with adhesion, etc., are anticipated, as observed for the
Cu(hfac)L compounds mentioned above.
[0009] 3. CVD copper from (Y)Cu(L) compounds.
[0010] In these Cu(+1) precursors, (Y) is an organic anion and (L)
is a neutral stabilizing ligand, such as trialkyphosphine. An
example of such a precursor is CpCuPEt.sub.3, where Cp is
cyclopentadienyl and PEt.sub.3 is triethylphoshine (Beech et al.,
Chem. Mater. (2), pages 216-219 (1990)). Under CVD conditions, two
of these precursor molecules react on the wafer surface in a
process whereby the two stabilizing trialkyphosphine ligands become
disassociated from the copper centers, the two (Y) ligands become
coupled together and the copper (+1) centers are reduced to copper
metal. The overall reaction is shown below in Equation (c).
However, this type of chemistry poses problems in a manufacturing
environment, since the released trialkylphosphine ligands tend to
contaminate the CVD chamber and can act as undesired N-type silicon
dopants.
2 (Y)Cu(L).fwdarw.2Cu+(Y-Y)+2(L) (c)
BRIEF SUMMARY OF THE INVENTION
[0011] The present invention is directed to a group of novel
homologous eight membered ring compoundss having a metal, such as
copper, reversibly bound in the ring and containing carbon,
nitrogen, silicon and/or other metals. A structural representation
of the compounds of this invention is shown below [1]: 2
[0012] wherein M and M' are each a metal, such as Cu, Ag, Au, and
Ir; X and X' can be N or O; Y and Y' can be Si, C; Sn, Ge, or B;
and Z and Z' can be C, N, or O. Substituents represented by R1, R2,
R3, R4, R5, R6, R1', R2', R3', R4', R5', and R6' will vary
depending on the ring atom to which they are attached. For example,
R1, R2, R1', and R2' can each independently be an alkyl, an
alkenyl, an alkynyl, a partially fluorinated an alkyl, an aryl, an
alkyl-substituted aryl, a partially fluorinated aryl, or a
fluoralkyl-substituted aryl; R3, R4, R3', and R4' can each be
independently an alkyl, a partially fluorinated an alkyl, a
trialkyl siloxy, an aryl, an alkyl-substituted aryl, a partially
fluorinated aryl, a fluoroalkyl-substituted aryl, an alkoxy, or a
halogen; and each of R5, R6, R5', and R6'can each be independently
H, an alkyl, an alkenyl, an alkynyl, a partially fluorinated an
alkyl, an aryl, an alkyl-substituted aryl, a partially fluorinated
aryl, a fluoralkyl-substituted aryl, a halogen, a trialkylsilyl, a
triarylsilyl, a trialkylsilanoate, a trialkylsilylamido, or an
alkoxy; provided that when X and X' are each O, there is no
substitution at R2 and R2'; further provided that when Z and Z' are
each O, there is no substitution at R5, R6, R5', or R6';. Alkyl and
alkoxy each have 1 to 8 carbons; alkenyl and alkynyl each have 2 to
8 carbons; and aryl has 6 carbons.
[0013] A linear representation of one embodiment of the novel
compounds of this invention is
[--CuNMe.sub.2SiMe.sub.2CH.sub.2CuNMe.sub.2SiMe.sub.2CH- .sub.2-]
in which, according to structure [1] above, M and M' are each Cu; X
and X' are each N; Y and Y' are each Si; Z and Z' are each C; R1,
R2, R3, R3, R1', R2', R3', and R4' are each methyl; and R5, R6,
R5', a R6' are each H.
[0014] The compounds of this invention have the remarkable
capability of depositing two metal atoms per molecule under
chemical vapor deposition conditions by the process of thermal
ligand coupling along with simultaneous reduction of the copper
centers to copper metal. They are also well suited for use in
Atomic Layer Deposition (ALD) of metal or oxide thin films,
preferably copper or copper oxide films.
[0015] This invention is also directed to depositing metal and
metal-containing films on a substrate, under ALD or CVD conditions,
using the above novel compounds as precursors.
BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS
[0016] FIG. 1 presents a single crystal X-ray structure of one
compound of this invention.
DETAILED DESCRIPTION OF THE INVENTION
[0017] The present invention describes a new family of volatile
cyclic bimetallic metal precursors, that contain either no
fluorine, or low levels of fluorine, relative to the (hfac) ligand
described above,or other fluorocarbon bearing ligands, and as such,
are expected to provide copper CVD films with excellent adhesion to
tantalum barriers. Being cyclic binuclear species, each molecule of
precursor contains two ligands, that can reductively couple
together and in the process release two atoms of metal. Using
copper as an example, metallization has the potential to proceed
via intramolecular reductive elimination, as shown below in
equation (d) for the binuclear complex [--CuNMe.sub.2SiMe.sub.2C-
H.sub.2CuNMe.sub.2SiMe.sub.2CH.sub.2--],rather than the more common
intermolecular reductive elimination shown above in equation
(c).
[--CuNMe.sub.2SiMe.sub.2CH.sub.2CuNMe.sub.2SiMe.sub.2CH.sub.2--].fwdarw.Me-
.sub.2NSiMe.sub.2CH.sub.2CH.sub.2SiMe.sub.2NMe.sub.2+2 Cu.sup.0
(d)
[0018] In the equation (c), two molecules of precursor need to
interact on a substrate for the reductive coupling and copper
nucleation to occur. The kinetic barrier for that process is
expected to result in a slower rate of copper nucleation, when
compared to the precursors of the present invention. While not
wishing to be bound by theory, the net result should be a faster
rate of nucleation for the bimetallic precursors of this invention
which allows less time for other undesired reactions with the
substrate to occur.
[0019] CVD copper can also be formed from these complexes using
direct chemical reduction of the complex using a suitable volatile
reducing agent such as a silane, borane, hydrazine etc or hydrogen
either as a simple gas or as a direct or remote plasma to release,
as volatile species, the ligands coordinated to copper while
simultaneously reducing the copper (+1) centers to copper metal.
This is illustrated below in equation (e) for the hydrogen
reduction of the binuclear complex
[--CuNMe.sub.2SiMe.sub.2CH.sub.2CuNMe.sub.2SiMe.sub.2CH.sub.2--] to
release dimethylaminotrimethylsilane and copper metal.
[--CuNMe.sub.2SiMe.sub.2CH.sub.2CuNMe.sub.2SiMe.sub.2CH.sub.2--]
+H.sub.2.fwdarw.Me.sub.2NSiMe.sub.3 +2Cu.sup.0 (e)
[0020] In addition, this new class of binuclear metal complexes are
anticipated to be excellent precursors for ALD (Atomic Layer
Deposition) growth of metal or metal-containing films.
[0021] In ALD the precursor is chemisorbed onto a substrate to form
a `monolayer` of precursor,i.e., one molecule thick. A second
reagent species is then similarly introduced to chemically react
with the first chemisorbed layer to grow the desired film onto the
substrate surface. For example, aluminum oxide can be grown by the
ALD process (Higashi, G.S., et al, AppL Phys. Lett., 55(19) (1989)
page 1963; Georghe S. M., et al, Int. Symp. On Atomic Layer Epitaxy
and Related Surface Processes (ALE-3) Abstracts, Sendai, Japan,
2527 May (1994) page 38) by first exposing a substrate bearing
surface OH groups to trimethylaluminum vapor to form a chemisorbed
monolayer that contains Al--O and residual Al--CH.sub.3 bonds and
then secondly to water vapor. The water vapor reacts with the
residual Al--CH.sub.3 groups to give solid aluminum oxide and
methane gas, the latter being exhausted from the ALD chamber as a
volatile byproduct. Since the water vapor is added in excess, each
aluminum atom in the newly formed aluminum oxide surface becomes
functionalized with an OH group. This creates a highly reactive
surface for the next pulse of trimethyl aluminum vapor to chemisorb
onto, again releasing methane in the process. This cycle is then
repeated to grow a perfectly conformal and pure film of aluminum
oxide whose thickness is determined by the number of cycles run.
Precursors that are best suited to ALD are readily volatile, have
high chemical reactivity permitting their ligands to be readily
removed by the addition of specific reagents and, at the molecular
level, are dense in the element to be deposited (reacted) onto the
substrate surface. A high ratio of the latter element to its
supporting ligands translates to a high effective loading of the
element per chemisorbed monolayer and hence to a higher ALD growth
rate.
[0022] The binuclear metal complexes described in this disclosure
are highly suitable for ALD since they are highly volatile, are
very reactive at low processing temperatures towards loss of their
ligands to form a metal-containing film and being binuclear they
bear two metal atoms per molecule of precursor in the chemisorbed
layer.
[0023] ALD copper using copper.sup.(+1) chloride (Martensson, P.,
et al, Chem Vap Deposition, 1997, Vol.3, No. 1, page 45) suffers
the disadvantage of low volatility of the precursor, ALD copper
from copper.sup.(+2) bis(tetramethylheptanedionate) (Martensson,
P., et al, J. Electrochem. Soc., Vol 145, No 8, August 1998, pages
2926-2931 suffers from the precursor being bulky and mononuclear in
copper, and ALD copper using copper.sup.(+2)(hfac).sub.2 (Solanki,
R., et al, Electrochemical and Solid State Letters, Vol. 3 (10)
pages 479-480 (2000)) suffers from the disadvantages of being
mononuclear and highly fluorinated.
[0024] The complexes described in this disclosure are highly
suitable for the ALD growth of copper and other metals, copper
alloys, and copper containing films such as copper sulfide, copper
oxide, etc. These films are created by reacting the monolayers of
precursor in the ALD technique by thermal processing or chemical
reduction, by treatment with other metal compounds or by processing
with sulfur or oxygen containing reagents respectively. This
disclosure also teaches a superior process for growing copper films
by ALD whereby the chemisorbed monolayer of precursor is reacted
with water vapor or water vapor plus an oxidant in ALD type cycles
to form an ultra thin film of copper oxide. This copper oxide is
then reduced by hydrogen gas, remote hydrogen plasma or other
suitable reductant, to form copper metal. These oxidation and
reduction steps can be carried out in rapid succession or reduction
can be carried out after a number of layers of oxide have been
grown. This improved ALD approach achieves a greater degree of
control over the formation of precursor monolayers since the
precursor can strongly chemisorb onto an oxide or hydroxide type of
surface rather than weakly absorbing onto a metallic surface. The
precursors described in this disclosure are especially suited to
this approach since they are hydrolytically labile. Thus, in the
case of the binuclear complex, [--CuNMe.sub.2SiMe.sub.2CH.su-
b.2CuNMe.sub.2SiMe.sub.2CH.sub.2--1, water vapor can break the
Cu-CH.sub.2 bond in the precursor by protonation of the carbon atom
and break the Si-N bond by hydrolysis thereby yielding smaller
molecular fragments that are more readily evacuated from the ALD
chamber as volatile by products, as shown below in equation (f).
This is illustrated by the result that in tetrahydrofuran solvent
the [ --CuNMe.sub.2SiMe.sub.2CH.sub.2CuNMe.sub.2S-
iMe.sub.2CH.sub.2--] complex is observed to release dimethylamine
and hexamethyldisiloxane upon reaction with water.
[--CuNMe.sub.2SiMe.sub.2CH.sub.2CuNMe.sub.2SiMeCH.sub.2--]+2H.sub.2O.fwdar-
w.Cu.sub.2O+2HNMe.sub.2+Me.sub.3SiOSiMe.sub.3 (f)
[0025] The copper oxide thus produced is then reduced to copper
metal by treatment with hydrogen gas, hydrogen plasma or other
suitable reducing agent.
[0026] In summary, the process sequence for growing ALD copper
using this superior process is as follows: a fresh metal, metal
containing, metalloid, such as silicon or germanium, or metalloid
containing surface is reacted with water, hydrogen peroxide,
alcohol oxygen or other suitable reagent to give a new surface
bearing hydroxyl OH, OH and oxide, or oxide oxygen groups. A
monolayer of copper complex is then chemisorbed onto this surface
to give copper oxide or hydroxide type species. A pulse of copper
complex is then added to chemisorb a monolayer of it onto the
hydroxide/oxide surface. The cycle of oxidant/copper precursor is
continued until the desired thickness of oxide is achieved at which
point the process is terminated by chemical reduction of the oxide
layers to copper metal using a suitable volatile reducing agent,
such as hydrogen, hydrogen plasma, silanes, and boranes. The
thickness of the oxide layers is carefully chosen such that the
oxide can be rapidly and completely reduced to metal. Once this is
complete then the entire cycle can be restarted to yield an overall
thicker final copper film. If the
[--CuNMe.sub.2SiMe.sub.2CH.sub.2CuNMe.sub.2SiMe.sub.2CH.sub.2--]
type precursor is utilized, it is thought that chemisorbtion onto a
[--Cu--OH] surface site to form [Cu--O--Cu] should be strongly
driven due to the basicity of the ligands driving proton removal
from the OH group. This chemisorbtion is far stronger than the
chemisorbtion of the same copper precursor directly onto a growing
copper surface to give [--Cu--CuL--] type species which is
representative of a typical ALD copper process. Thus greater
control over monolayer saturation is achieved which is the key to a
successful ALD approach. The resulting [--Cu--O--CuL] or
[--Cu--O--Cu] surface is then reduced to [--Cu--Cu] to give a
smooth copper film. This technique can also be applied to the
formation of mixed metal alloy thin films by ALD. In this technique
layers of copper oxide grown by ALD are alternated with additional
layers of another metal oxide which can also be reduced to
elemental metal by hydrogen or another reducing agent
simultaneously with the reduction of copper oxide to copper metal.
The ratio of copper oxide layers to alloying metal oxide layers
determines the composition of the final metal alloy after
reduction. For instance, copper oxide could be grown alternately
with palladium oxide and this composite reduced to give a copper
palladium alloy. Similarly, more than one additional metal oxide
species can be incorporated into the copper oxide to yield, after
reduction an alloy comprised of copper and at least two other
metals. Specific copper alloys are more electromigration resistant
than pure copper and hence are very important for the fabrication
of copper interconnects. If the ALD copper alloy film forms a seed
layer for subsequent electroplated copper, the alloying element(s)
can be diffused into the bulk of the electroplated copper by
applying a thermal anneal step resulting in a copper film
containing uniformly distributed alloying elements.
[0027] Some copper alloys are advantageous for other reasons such
as the alloying element segregating to the surface of the copper
film after a thermal anneal whereupon it can be reacted with a
processing gas or vapor to provide a protective layer. An example
would be the growth and annealing of a copper/magnesium alloy
whereby the magnesium segregates to the copper surface where it is
subsequently oxidized to form a protective layer of magnesium oxide
(Murarka, S., Critical Reviews in Solid State and Materials
Sciences, 20 (2), pages 87-124 (1995))
[0028] Other metals (M) can also be used instead of copper to give
[--MNMe.sub.2SiMe.sub.2CH.sub.2MNMe.sub.2SiMeCH.sub.2--] type of
complexes described in this disclosure thereby yielding volatile
metal complexes other than copper that are usefull for CVD or ALD
films containing those respective metals. Examples of such metals
include, but are not limited to, silver, gold, cobalt, ruthenium,
rhodium, platinum, palladium, nickel, osmium and iridium, sodium,
potassium and lithium. Such complexes can also be used in
conjunction with, or in alternating sequences with
[--CuNMe.sub.2SiMe.sub.2CH.sub.2CuNMe.sub.2SiMe.sub.2CH.su- b.2--]
type copper complexes to give copper alloys after a thermal anneal.
Other metals that are divalent such as, but not limited to,
palladium, platinum, rhodium and ruthenium can also be used to
yield useful volatile complexes by coordinating ligands of the type
shown in structure [1]. Such complexes can also be used in a
simultaneous CVD deposition or ALD deposition with suitable copper
complexes to yield copper alloys or other copper containing films.
These new approaches to ALD copper and copper alloys and other
copper containing films can also be applied using knowncopper
precursors such as those described in the 10 groups below:
[0029] 1) Cu.sup.+1(.beta.-diketonate)(L)n type precursors where
(n) is 1 or 2 or where (L) represents an olefin, a diene, a
tetraene, an alkyne trialkylsilylalkenes, trialkylsilyidienes
trialkylsilytetraenes, trialkylsilylacetylenes,
trialkoxysilylalkenes, trialkoxysilyldienes
trialkoxysilylacetlylenes, trialkoxysilyidienes, trialkyl
phosphines, and trialkoxyphoshines, nitriles, isonitriles,
isocyanates, carbon monoxide, and and (.beta.-diketonate) is
represented by (hfac), acetylacetonate (i.e., acac),
3-halosubstituted acac; 1,5-dihalo substituted acac,
1,1,1-trihalosubstituted acac, alkylacetoacetates
(methylacetoacetate), alkyl-oxo-butanoates, aryl acetoacetates.
.beta.-diketonate can also be substituted by aryl or alkyl
substituted, halogenated, partly halogenated or non-halogenated
.beta.-diimine or .beta.-ketoimine, malonaldehyde,
2-halo-malonaldehyde, malonaldehyde diimines, dialkyl malonates
(e.g. dimethyl malonate), diaryl malonates, arylalkyl malonates,
1,3bis(trialkylsilyl)-1,3-propanedionate and
1-trialkylsilyl-3-alkyl-1 ,3-propanedionate.
[0030] 2) Cu.sup.+1(alkoxide)n type precursors where (n) is
typically from 4-6 and (alkoxide) represents t-butoxy, methoxy,
ethoxy, isopropoxy, unsaturated alkoxides (e.g.
2-methyl-3-butene-2-oxy, 2-methyl-3-butene-2-oxy), alkynyloxy (e.g.
propargyl alkoxide), allyloxy, vinyloxy, allylphenoxy, alkylphenoxy
or mixtures thereof. Additional alkoxides include amino, imino ,
cyano and halogen substituted alkoxides, trialkylsilanoate,
trialkoxysilanoate, dialkylalkylaminosilanoate,
dialkylalkyliminosilanoate
[0031] 3) [Cu.sup.(+1)(amide)]n type precursors where (n) is
typically 4-6 and (amide) represents secondary amide anion.
Substituents on the amide nitrogen include but are not limited to
the following representative groups: alkyl, aryl, allyl, arylalkyl,
silylalkyl, silylaryl, alkylether, halogenated and partially
halogenated dialkylsilyl.
[0032] 4) [(Cu.sup.(+1)(R)]n type precursors where (n) is typically
between 4-6 and (R) represents alkyl, halogenated or partially
halogenated alkyl, trialkoxysilylalkyl, trialkylsilylalkyl,
trialkoxysilylalkyl, allyl, vinyl, alkynyl, aryl, mono and
multi-alkyl substituted aryls, halo substituted aryls, arylalkyls,
halo substituted araalkyls, alkoxy substituted aryls, alkoxy
substituted aralkyls, iminosubstituted aryls and iminosubstituted
alkyls.
[0033] 5) Cu.sup.(+2)bis(alkoxide) type precursors including, but
not limited to, alkoxides substituted with amine, imine, ether,
vinyl, alkynyl, aryl, trialyklsilyl or halogen. The alkoxide can
also be dialkylalkylaminosilanoate or
dialkylalkyliminosilanoate
[0034] 6) Cu.sup.(+2)bis [.beta.-diketonate] type precursors where
[.beta.-diketonate] can be substituted with alkyl, halogenated
alkyl, vinyl, alkynyl, aryl, trialkylsilyl, halogen or ether
groups.
[0035] 7) Cu.sup.(+2)bis(.beta.ketoimides) where the
.beta.-ketoimine is substituted with alkyl, halogenated alkyl,
trialkylsilyl, trialkoxysilyl, trialkylsiloxyl, aryl, halogenated
aryl, ether or amine groups
[0036] 8) Cu.sup.(+2)(.beta.-diimides) where the .beta.-diimine is
substituted with hydrogen, alkyl, halogenated alkyl, trialkylsilyl,
trialkoxysilyl. trialkylsiloxy, aryl, halogenated aryl, amine and
ether groups
[0037] 9) Cu.sup.(+1)(amidinates) where (amidinate) represents
alkyl-amidinate, aryl-amidinate, halo-amidinate,
trialkylsilyamidinate, trialkylsilylalkylamidinate and
trialkoxysilylamidinate structures.
[0038] 10) Cu.sup.(+1)(R)nL type precursors where (n) is typically
1-3 and where (R) represents alkyl, halogenated alkyl, amine
substituted alkyl, imine substituted alkyl allyl, vinyl, alkynyl,
aryl, alkyl substituted aryls, halosubstituted aryls, arylalkyls,
halo substituted arylalkyls, alkoxy substituted aryls, alkoxy
substituted arylalkyls, nitriles, haloalkanes, cyclopentadienyl,
halogen substituted cyclopentadienyl, alkyl substituted
cyclopentadienyl, halogenatedalkyl substituted cyclopentadienyl. L
is a neutral stabilizing ligand of the type trialkylphosphine,
triarylphosphine, dialkylphosphine, CO, nitrile, isonitrile,
isocyanides, olefin, alkyne.
[0039] The ligand basicity of the
[--CuNMe.sub.2SiMe.sub.2CH.sub.2CuNMe.su- b.2SiMe.sub.2CH.sub.2--]
type complexes can also be used in another ALD approach where a
monolayer of chemisorbed complex of the type [1] is treated with a
volatile acid ligand such as a .beta.-diketone which protonates off
the ligand of the complex and in doing so forms a metastable copper
(+1) (.beta.-diketonate) species which then disproportionates to
give volatile copper (+2) (.beta.-diketonate).sub.2 and copper
metal. This same chemistry can also be used in a CVD process for
growing a copper film.
[0040] A structural representation of the metal complexes of this
invention is shown below [1] 3
[0041] wherein M and M' are each a metal such as Cu, Ag, Au, and
Ir; X and X' can be N or O; Y and Y' can be Si, C; Sn, Ge, or B;
and Z and Z' can be C, N, or O. Substituents represented by R1, R2,
R3, R4, R5, R6, R1', R2', R3', R4', R5', and R6' will vary
depending on the ring atom to which they are attached. Additional
embodiments include Mand M' as divalent metals, such as Pt and Pd,
where each metal center coordinates two of its own ligands.
[0042] A single crystal X-ray structure of one embodiment of the
compounds of this invention,
[--CuNMe.sub.2SiMe.sub.2CH.sub.2CuNMe.sub.2SiMe.sub.2C- H.sub.2--],
is shown in FIG. 1.
[0043] The eight membered cyclic core structure of this molecule
constitutes a novel composition with unique metallization
properties for copper and other metal CVD and ALD techniques, as
mentioned above. Many variations of the above molecule are possible
to bestow subtle changes in chemical and physical properties of the
precursor. For instance, the periphery of the core structure can be
modified by alkyl substitition to render the complex a liquid at
room temperature
[0044] The following compositions are alternative preferred
embodiments. In each of the following 12 types of compounds, M and
M' are Cu. Different substitutions can be on X and X' (Group 1), Y
and Y' (Group 2) and Z and Z' (Group 3). In all of the
substitutions, alkyl and alkoxy can have 1 to 8 carbons, alkene,
and alkyne can each have 2 to 8 carbons, and aryl can have 6
carbons.
[0045] The core ring structure, when X and X' are N, Y and Y' are
Si, and Z and Z' are C, is [--Cu--N--Si--C--Cu--N--Si--C--],
denoted as Structure Type #1. Formulations for Structure Type
#1:
[0046] Group 1: Substituents on X and X' (N) R1R2, R1', and R2' can
be any combination of alkyl, alkynes, alkenes, partially
fluorinated alkyl, aryl, alkyl-substituted aryl, partially
fluorinated aryl, or fluoroalkyl-substituted aryl.
[0047] Group 2: Substituents on Y and Y' (Si)
[0048] R3, R3, R3', and R4' can be any combination of alkyl,
partially fluorinated alkyl, trialkylsiloxy, triarylsiloxy, aryl,
alkyl-substituted aryl, partially fluorinated aryl,
fluoroalkyl-substituted aryl, alkoxy, alkylamido,.or halogen.
[0049] Group 3: Substituents on Z and Z' (C)
[0050] Either or all of R5, R6, R5' and R6' are hydrogen, a
alkenes, alkyne, alkyl, partially fluorinated alkyl, aryl,
alkyl-substituted aryl, partially fluorinated aryl,
fluoroalkyl-substituted aryl, trialkylsilyl, trialkylsilylalkyl,
triarylsily, trialkylsiloxy, triarylsiloxy, trialkylsilanoate,
alkoxy, trialkylsilylamido, or halogen.
[0051] Further, an analogous eight member ring core structure can
also be created when Z and Z' are each N]. This would create
another new class of CVD copper precursors, with great potential
for yielding highly adherent films to tantalum. In the list below,
different substitution groups are shown for X and X' (N)(Group 1),
Y and Y' (Si) (Group 2) and Z and Z' (N) (Group 3). The core ring
structure is [--Cu--N--Si--N--Cu--N--Si--N--], denoted as Structure
Type #2.
[0052] Formulations for Structure Type #2.
[0053] Group 1: Substituents on X and X' (N)
[0054] R1R2, R1', and R2' can be any combination of hydrogen,
alkyl, alkyne, alkene, partially fluorinated alkyl, aryl,
alkyl-substituted aryl, partially fluorinated aryl, or
fluoroalkyl-substituted aryl, trialkylsilyl, or triarylsilyl.
[0055] Group 2: Substituents on Y and Y' (Si)
[0056] R3, R3, R3', and R4' can be any combination of alkyl,
partially fluorinated alkyl, trialkylsiloxy, triarylsiloxy, aryl,
alkyl-substituted aryl, partially fluorinated aryl,
fluoroalkyl-substituted aryl, alkoxy, alkylamido,.or halogen.
[0057] Group 3: Substituents on Z and Z' (N)
[0058] R5, R6, R5', and R6' are independently hydrogen, alkene,
alkyne, alkyl, partially fluorinated alkyl, aryl, alkyl-substituted
aryl, partially fluorinated aryl, fluoroalkyl-substituted aryl,
trialkylsilyl, triarysilyl, or halogen.
[0059] Further, an analogous eight member ring core structure can
also be created when Z and Z' are each anionic O. This would create
another new class of CVD copper precursors, with great potential
for yielding highly adherent films to tantalum. In the list below,
different substitution groups are shown for nitrogens X and X'
(N)(Group 1), Y and Y' (Si) (Group 2). Different binuclear
complexes are created by combining the following varyingly
substituted Groups 1 and 2, along with Z and Z' as (O)', as they
are connected together through two copper atoms to yield an eight
membered ring, Thus, the core ring structure is
[--Cu--N--Si--O--Cu--N--Si--O--], denoted as Structure Type #3.
[0060] Formulations for Structure Type #3.
[0061] Group 1: Substituents on X and X' (N)
[0062] R1R2, R1', and R2' can be any combination of alkyl, alkynes,
alkenes, partially fluorinated alkyl, aryl, alkyl-substituted aryl,
partially fluorinated aryl, or fluoroalkyl-substituted aryl.
[0063] Group 2: Substituents on Y and Y' (Si) R3, R3, R3', and R4'
can be any combination of alkyl, partially fluorinated alkyl,
trialkylsiloxy, triarylsiloxy, aryl, alkyl-substituted aryl,
partially fluorinated aryl, fluoroalkyl-substituted aryl, alkoxy,
alkylamido, or halogen.
[0064] Further, an analogous eight member ring core structure can
also be created Y and Y' are C. This would also create another new
class of CVD copper precursors, with great potential for yielding
highly adherent films to tantalum. In the list below, different
substitution groups are shown for: X and X' (N)(Group 1), Y and Y'
(C) (Group 2) and Z and Z' (C), (Group 3). Different binuclear
complexes are created by combining the following varyingly
substituted Groups 1, 2 and 3, as they are connected together
through the two copper atoms to yield an eight membered ring. Thus,
the core ring structure is [--Cu--N--C--C--Cu--N--C-- -C--],
denoted as Structure Type #4.
[0065] Formulations for Structure Type #4.
[0066] Group 1: Substituents on X and X' (N) R1R2, R1', and R2' can
be any combination of alkyl, alkynes, alkenes, partially
fluorinated alkyl, aryl, alkyl-substituted aryl, partially
fluorinated aryl, or fluoroalkyl-substituted aryl.
[0067] Group 2: Substituents on Y and Y' (C)
[0068] R3, R3, R3', and R4' can be any combination of hydrogen,
alkyl, partially fluorinated alkyl, trialkylsiloxy , triarylsiloxy,
alkoxy, aryl, alkyl-substituted aryl, partially fluorinated aryl,
fluoroalkyl-substituted aryl, or halogen.
[0069] Group 3: Substituents on Z and Z' (C)
[0070] Either or all of R5, R6, R5' and R6' are H, alkenes, alkyne,
alkyl, partially fluorinated alkyl, aryl, alkyl-substituted aryl,
partially fluorinated aryl, fluoroalkyl-substituted aryl,
trialkylsilyl, trialkylsilylalkyl, triarylsily, trialkylsiloxy,
triarylsiloxy, trialkylsilanoate, alkoxy, trialkylsilylamido, or
halogen.
[0071] Further, an analogous eight member ring core structure can
also be created when Y and Y' are C, and Z and Z' are N. This would
also create another new class of CVD copper precursors, with great
potential for yielding highly adherent films to tantalum. In the
list below, different substitution groups are shown for X and X'
(N)(Group 1), Y and Y' (C ) (Group 2) and Z and Z' (C ) (Group 3).
Different binuclear complexes are created by combining the
following varyingly substituted Groups 1, 2 and 3. Thus, the core
ring structure is [--Cu--N--C--N--Cu--N--C--N--], denoted as
Structure Type #5.
[0072] Formulations for Structure Type #5.
[0073] Group 1: Substituents on X and X' (N)
[0074] R1R2, R1', and R2' can be any combination of alkyl, alkynes,
alkenes, partially fluorinated alkyl, aryl, alkyl-substituted aryl,
partially fluorinated aryl, or fluoroalkyl-substituted aryl.
[0075] Group 2: Substituents on Y and Y' (C)
[0076] R3, R3, R3', and R4' can be any combination of H, alkyl,
partially fluorinated alkyl, trialkylsiloxy , triarylsiloxy,
alkoxy, aryl, alkyl-substituted aryl, partially fluorinated aryl,
fluoroalkyl-substituted aryl, or halogen.
[0077] Group 3: Substituents on Z and Z' (N)
[0078] R5, R6, R5', and R6' are independently hydrogen, alkene,
alkyne, alkyl, partially fluorinated alkyl, aryl, alkyl-substituted
aryl, partially fluorinated aryl, fluoroalkyl-substituted aryl,
trialkylsilyl, triarysilyl, or halogen.
[0079] Further, an analogous eight member ring core structure can
also be created Y and Y' are C, and Z and Z' are O. This would also
create another new class of CVD copper precursors, with great
potential for yielding highly adherent films to tantalum. In the
list below, different substitution groups are shown for nitrogens X
and X' (N)(Group 1), Y and Y' (C ) (Group 2). Different binuclear
complexes are created by combining the following varyingly
substituted Group 1, Group 2 and oxygens.Thus, the core ring
structure is [--Cu--N--C--O--Cu--N--C--O--], denoted as Structure
Type #6.
[0080] Formulations for Structure Type #6.
[0081] Group 1: Substituents on X and X' (N)
[0082] R1R2, R1', and R2' can be any combination of alkyl, alkynes,
alkenes, partially fluorinated alkyl, aryl, alkyl-substituted aryl,
partially fluorinated aryl, or fluoroalkyl-substituted aryl.
[0083] Group 2: Substituents on Y and Y' (C) R3, R3, R3', and R4'
can be any combination of H, alkyl, partially fluorinated alkyl,
trialkylsiloxy , triarylsiloxy, alkoxy, aryl, alkyl-substituted
aryl, partially fluorinated aryl, fluoroalkyl-substituted aryl, or
halogen.
[0084] Further, an analogous eight membered ring core structure can
also be created when X and X' are O. This would also create another
new class of CVD copper precursors, with great potential for
yielding highly adherent films to tantalum. In the list below,
different substitution groups are shown for X and X' (O) (Group 1),
Y and Y' (Si) (Group 2) and Z and Z' (C) (Group 3). Different
binuclear complexes are created by combining the following
varyingly substituted Group 1, Group 2 and Group 3, as they are
connected together through two copper atoms to yield an eight
membered ring. Thus, the core ring structure is
[--Cu--O--Si--C--Cu--O--Si--C--], denoted as Structure Type #7.
[0085] Formulations for Structure Type #7.
[0086] Group 1: Substituents on X and X' (O)
[0087] R1 and R1' are individually alkyl, alkynes, alkenes,
partially fluorinated alkyl, aryl, alkyl-substituted aryl,
partially fluorinated aryl, fluoroalkyl-substituted aryl,
trialkylsilyl, or triarylsilyl. There is no substitution at R2 and
R2'.
[0088] Group 2: Substituents on Y and Y' (Si)
[0089] R3, R3, R3', and R4' can be any combination of alkyl,
partially fluorinated alkyl, trialkylsiloxy, triarylsiloxy, aryl,
alkyl-substituted aryl, partially fluorinated aryl,
fluoroalkyl-substituted aryl, alkoxy, alkylamido, or halogen.
[0090] Group 3: Substituents on Z and Z' (C)
[0091] Either or all of R5, R6, R5' and R6' are H, alkenes, alkyne,
alkyl, partially fluorinated alkyl, aryl, alkyl-substituted aryl,
partially fluorinated aryl, fluoroalkyl-substituted aryl,
trialkylsilyl, trialkylsilylalkyl, triarylsily, trialkylsiloxy,
triarylsiloxy, trialkylsilanoate, alkoxy, trialkylsilylamido, or
halogen.
[0092] Further, an analogous eight membered ring core structure can
also be created X and X' are O and Z and Z' are N. This would also
create another new class of CVD copper precursors, with great
potential for yielding highly adherent films to tantalum. In the
list below, different substitution groups are shown for Xand X'
(O)(Group 1), Y and Y' (Si) (Group 2) and Z and Z' (N) (Group 3).
Thus, the core ring structure is [--Cu--O--Si--N--Cu--O--Si--N--],
denoted as Structure Type #8.
[0093] Formulations for Structure Type #8.
[0094] Group 1: Substituents on X and X' (O)
[0095] R1 and R1' are individually alkyl, alkynes, alkenes,
partially fluorinated alkyl, aryl, alkyl-substituted aryl,
partially fluorinated aryl, fluoroalkyl-substituted aryl,
trialkylsilyl, or triarylsilyl. There is no substitution at R2 and
R2'.
[0096] Group 2: Substituents on Y and Y' (Si)
[0097] R3, R3, R3', and R4' can be any combination of alkyl,
partially fluorinated alkyl, trialkylsiloxy, triarylsiloxy, aryl,
alkyl-substituted aryl, partially fluorinated aryl,
fluoroalkyl-substituted aryl, alkoxy, alkylamido, or halogen.
[0098] Group 3: Substituents on Z and Z' (N)
[0099] R5, R6, R5', and R6' are independently hydrogen, alkene,
alkyne, alkyl, partially fluorinated alkyl, aryl, alkyl-substituted
aryl, partially fluorinated aryl, fluoroalkyl-substituted aryl,
trialkylsilyl, triarysilyl, or halogen.
[0100] Further, an analogous eight membered ring core structure can
also be created when X and X' are O, and Z and Z' are O. This would
also create another new class of CVD copper precursors, with great
potential for yielding highly adherent films to tantalum. In the
list below, different substitution groups are shown for X and X'
(O) (Group 1) and Y and Y' (Si) (Group 2). Thus, different
binuclear complexes are created by combining the following
varyingly substituted Group 1, Group 2 and oxygen atoms, as they
are connected together through two copper atoms to yield an eight
membered ring. Thus, the core ring structure is
[--Cu--O--Si--O--Cu--O--Si--O--], denoted as Structure Type #9.
[0101] Formulations for Structure Type #9.
[0102] Group 1: Substituents on X and X' (O)
[0103] R1 and R1 ' are individually alkyl, alkynes, alkenes,
partially fluorinated alkyl, aryl, alkyl-substituted aryl,
partially fluorinated aryl, fluoroalkyl-substituted aryl,
trialkylsilyl, or triarylsilyl. There is no substitution at R2 and
R2'.
[0104] Group 2: Substituents on Y and Y' (Si)
[0105] R3, R4, R3', and R4' can be any combination of alkyl,
partially fluorinated alkyl, trialkylsiloxy, triarylsiloxy, aryl,
alkyl-substituted aryl, partially fluorinated aryl,
fluoroalkyl-substituted aryl, alkoxy, alkylamido, or halogen.
[0106] Further, an analogous eight membered ring core structure can
also be created when X and X' is N and Y and Y' are C. This would
also create another new class of CVD copper precursors, with great
potential for yielding highly adherent films to tantalum. In the
list below, different substitution groups are shown for X and X'
(O) (Group 1) and Y and Y' (C) (Group 2). Thus, different binuclear
complexes are created by combining the following varyingly
substituted Group 1, Group 2 and Group 3, as they are connected
together through two copper atoms to yield an eight membered ring.
Thus, the core ring structure is [--Cu--O--C--C--Cu--O--C-- -C--],
denoted as Structure Type #10.
[0107] Formulations for Structure Type #10.
[0108] Group 1: Substituents on X and X' (O)
[0109] R1 and R1' are individually alkyl, alkynes, alkenes,
partially fluorinated alkyl, aryl, alkyl-substituted aryl,
partially fluorinated aryl, fluoroalkyl-substituted aryl,
trialkylsilyl, or triarylsilyl. There is no substitution at R2 and
R2'.
[0110] Group 2: Substituents on Y and Y' (C)
[0111] R3, R4, R3', and R4' can be any combination of hydrogen,
alkyl, partially fluorinated alkyl trialkylsiloxy, triarylsiloxy,
alkoxy, aryl, alkyl-substituted aryl, partially fluorinated aryl,
fluoroalkyl-substituted aryl, or halogen.
[0112] Group 3: Substituents on Z and Z' (C)
[0113] Either or all of R5, R6, R5' and R6' are H, alkenes, alkyne,
alkyl, partially fluorinated alkyl, aryl, alkyl-substituted aryl,
partially fluorinated aryl, fluoroalkyl-substituted aryl,
trialkylsilyl, trialkylsilylalkyl, triarylsily, trialkylsiloxy,
triarylsiloxy, trialkylsilanoate, alkoxy, trialkylsilylamido, or
halogen.
[0114] Further, an analogous eight membered ring core structure can
also be created when X and X' are O, Y and Y' are C, and Z and Z'
are N. This would also create another new class of CVD copper
precursors, with great potential for yielding highly adherent films
to tantalum. In the list below, different substitution groups are
shown for X and X' (O) (Group 1), Y and Y' (C) (Group 2) and Z and
Z' (N). Thus, the core ring structure is
[--Cu--O--C--N--Cu--O--C--N--], denoted a structure type #11.
[0115] Formulations for structure type #11.
[0116] Group 1: Substituents on X and X' (O)
[0117] R1 and R1' are individually alkyl, alkynes, alkenes,
partially fluorinated alkyl, aryl, alkyl-substituted aryl,
partially fluorinated aryl, fluoroalkyl-substituted aryl,
trialkylsilyl, or triarylsilyl. There is no substitution at R2 and
R2'.
[0118] Group 2: Substituents on Y and Y' (C)
[0119] R3, R4, R3', and R4' can be any combination of H, alkyl,
partially fluorinated alkyl, trialkylsiloxy, triarylsiloxy, alkoxy,
aryl, alkyl-substituted aryl, partially fluorinated aryl,
fluoroalkyl-substituted aryl, or halogen.
[0120] Group 3: Substituents on Z and Z' (N)
[0121] R5, R6, R5', and R6' are independently hydrogen, alkene,
alkyne, alkyl, partially fluorinated alkyl, aryl, alkyl-substituted
aryl, partially fluorinated aryl, fluoroalkyl-substituted aryl,
trialkylsilyl, triarysilyl, or halogen.
[0122] Further, an analogous eight membered ring core structure can
also be created when X and X' are O, Y and Y' are Si, and Z and Z'
are O. This would also create another new class of CVD copper
precursors, with great potential for yielding highly adherent films
to tantalum. In the list below, different substitution groups are
shown for X and X' (O) (Group 1), Y and Y' (C)(Group 2) and Z and
Z' (O). Thus, the core ring structure is
[--Cu--O--C--O--Cu--O--C--O--], denoted as Structure Type #12.
[0123] Formulations for Structure Type #12.
[0124] Group 1: Substituents on X and X' (O)
[0125] R1 and R1' are individually alkyl, alkynes, alkenes,
partially fluorinated alkyl, aryl, alkyl-substituted aryl,
partially fluorinated aryl, fluoroalkyl-substituted aryl,
trialkylsilyl, or triarylsilyl. There is no substitution at R2 and
R2'.
[0126] Group 2: Substituents on Y and Y' (C)
[0127] R3, R4, R3', and R4' can be any combination of hydrogen,
alkyl, partially fluorinated alkyl, trialkylsiloxy, triarylsiloxy,
alkoxy, aryl, alkyl-substituted aryl, partially fluorinated aryl,
fluoroalkyl-substituted aryl, or halogen.
[0128] A further series of structure types are also anticipated
where the silicon atoms Y and Y' are substituted with either tin
atoms, germanium atoms, boron atoms or aluminum atoms.
[0129] For tin, the core structures would become
[--Cu--O--Sn--O--Cu--O--S- n--O--],
[--Cu--O--Sn--N--Cu--O--Sn--N--] (two classes since O can be either
an ether or anionic oxygen), [--Cu--N--Sn--N--Cu--N--Sn--N--],
[--Cu--O--Sn--C--Cu--O--Sn--C--], or
[--Cu--N--Sn--C--Cu--N--Sn--C--] listed below as Structure Types
19, 20, 21, 22, 23, 24, respectively. For germanium substituted for
Si1 and Si1', an analogous series of compounds are also
generated.
[0130] Substitution on Z and Z', when they are oxygen, nitrogen or
carbon, for both the tin and germanium-based structures, can be as
listed for the substitution patterns on these elements as shown for
Structure Types 1-12. Substitution on tin or germanium can be as
listed for substitution on Si in Structure Types 1-12. By
substituting tin for silicon in the compounds listed as synthetic
precursors materials for Structure Types 1, 2, 3, 7, 8 and 9, then
following the same synthetic steps for the latter compounds,
synthetic routes to Structure Types 19, 20, 21, 22, 23 and 24,
along with the analogous germanium based series of Structure Types
is achieved.
[0131] For boron, the Structure Types would thus become
[--Cu--O--B--O--Cu--O--B--O--], [--Cu--O--B--N--Cu--O--B--N--] (two
classes since O can be either an ether or anionic oyxgen),
[--Cu--N--B--N--Cu--N--B--N--], [Cu--O--B--C--Cu--O--B--C--],
[--Cu--N--B--C--Cu--N--B--C--]. These are listed below as Structure
Types 13, 14, 15 16, 17 and 18, respectively. When Y and Y' are Al,
an analogous series of Structure Types can be generated.
Substituents on oxygen or nitrogen or carbon (C5 and C5') for both
the aluminum and boron based-Structure Types is to be as, but not
limited to, those listed for oxygen, nitrogen and carbon in
Structure Types 1-12. Boron or aluminum substituents can include,
but not be limited to, halogen (especially fluorine),
C.sub.1--C.sub.8 alkyl and fluoroalkyl, aryl and fluoroaryl,
partially fluorinated or unfluorinated alkoxide or silanoate,
amide.
CVD And ALD Processes
[0132] It is anticipated that the CVD and ALD processes for growing
pure copper metal, copper metal containing metallic alloys, and
other copper containing films or other metal films using the above
complexes will operate effectively under the following process
conditions in any combination:
[0133] (a) within a temperature range of zero to 500 degrees
Celcius
[0134] (b) within a pressure range of 1 mTorr to greater than 760
Torr
[0135] (c) with the use of microwave generated plasma, either
remote or direct
[0136] (d) with the use of the following reagent gases added
stoichiometrically or catalytically: hydrogen, ammonia, water
vapor, oxygen, nitrous oxide, hydrazines, amines, alcohols,
phosphines, silanes, boranes, alanes, or other chemically reactive
species capable of yielding metal containing films from these metal
precursors.
[0137] (e) vapors of other metal precursors in conjunction with
reagent gases as in (d) to grow copper metal alloys or other mixed
metal compounds, including copper. An example would be
superconducting YBaCu oxides.
[0138] (f) Volatile sulfur containing volatile compounds can be
added during the CVD process to form metal sulfides.
[0139] Any of the above compounds may also form useful precursors
for copper CVD when complexed to various neutral ligands, such as;
alcohols ethers, amines, alkenes, alkynes, arenes, phosphines,
carbon monoxide, nitriles, isonitriles, cyanates, or isocyanates,
imines, diimines, nitrogen containing heterocycles.
[0140] Especially beneficial compositions may be those complexes
that are liquid or especially volatile.
[0141] In the above complexes where the ligand system is not
bearing oxygen, for instance the Cu--N--Si--C--Cu--N--Si--C system,
it is anticipated that volatile complexes of oxophillic metals such
as magnesium, zirconium, etc., could be prepared that would be
chemically compatible with copper complexes prepared from the same
or similar ligands. CVD using a mixture of two such compounds
should permit the deposition of copper alloys, such as; Cu/Mg or
Cu/Zr, which are known to possess properties of enhanced
reliability and improved electromigration resistance. With the
selection of appropriate ligands, such mixtures can be prepared
that are liquid blends, and thus, especially suited to direct
liquid injection delivery to the CVD chamber.
[0142] Further, selected substituents on selected atoms that form
the core eight membered rings in all of the above compounds may
also include groups containing tin, such that this element can
become intermingled with the copper CVD film to give an alloy that
is more electromigration resistant than pure copper.
EXPERIMENTAL
SYNTHESIS
[0143] The
[--CuNMe.sub.2SiMe.sub.2CH.sub.2CuNMe.sub.2SiMe.sub.2CH.sub.2--- ]
complex was synthesized as follows. Under a blanket of nitrogen,
15.1 g (0.1 moles) of dimethylaminochloromethyidimethylsilane was
added to 2.4 g (0.1 moles) of magnesium in 200 ml dry
tetrahydrofuran. The mixture was stirred overnight at room
temperature to give a gray solution. 8.5 ml of dioxane was added in
one lot, stirred for 30 mins. and then the resulting magnesium
chloride/dioxane precipitate was filtered off. The filtrate was
then cooled on an ice bath to 6 degrees centigrade and 10 g of
cuprous chloride (0.1 moles) was added over 1 hour with stirring.
The mix was stirred one further hour at 6 degrees centigrade and
then allowed to warm to room temperature with continued stirring.
This mixture was filtered, and the filtrate stripped of solvent at
room temperature to give an off-white solid. This solid was placed
in a sublimator at 105 degrees centigrade and sublimed under
dynamic vacuum at 0.001 Torr to give a colorless crystalline
sublimate of the complex [--CuNMe.sub.2SiMe.sub.2CH-
.sub.2CuNMe.sub.2SiMe.sub.2CH.sub.2--]
[0144] Yield=5.0 g
[0145] .sup.1HNMR in deuterobenzene: singlet at 2.22 ppm (6H),
singlet at 0.21 ppm (6H), singlet at -0.33 ppm (2H).
[0146] .sup.13C NMR in deuterobenzene: singlet at -8.2 ppm, singlet
at -0.25 ppm, singlet at 40.1 ppm.
[0147] GCMS analysis of the purified
[--CuNMe.sub.2SiMe.sub.2CH.sub.2CuNMe- .sub.2SiMe.sub.2CH.sub.2--]
complex showed predominantly the product of ligand coupling, i.e.,
Me.sub.2NSiMe.sub.2CH.sub.2CH.sub.2Me.sub.2SiNMe.s- ub.2, due to
thermal reaction in the GC injector port.
[0148] In other experiments it was found that the application of
excessive heat greater than 120.degree. C. during sublimation of
the
[--CuNMe.sub.2SiMe.sub.2CH.sub.2CuNMe.sub.2SiMe.sub.2CH.sub.2--]
complex also begins to yield a copper film and the coupled ligand
Me.sub.2NSiMe.sub.2CH.sub.2CH.sub.2Me.sub.2SiNMe.sub.2 as the sole
volatile by product, identified by both GCMS and .sup.1HNMR. As
shown below, under CVD conditions we also observed the coupling of
the ligands in the
[--CuNMe.sub.2SiMe.sub.2CH.sub.2CuNMe.sub.2SiMe.sub.2CH.sub.2--]
complex simultaneous with growing a copper containing film.
CVD
[0149] Using a Vactronics LPCVD Reactor the Following Conditions
Were Used:
[0150] Precursor:
[--CuNMe.sub.2SiMe.sub.2CH.sub.2CuNMe.sub.2SiMe.sub.2CH.-
sub.2--]
[0151] Substrate: Tantalum sputtered onto a silicon wafer
1 Precursor delivery temperature: 75.degree. C. Chamber pressure:
1.5 Torr Wafer temperature: 143.degree. C. Carrier gas flow rate:
70 sccm Diluent gas flow rate: 100 sccm
[0152] This provided a copper containing film, as determined by an
EDX scan. Mass spectral analysis of the CVD chamber gases during
processing revealed the presence of
NMe.sub.2SiMe.sub.2CH.sub.2CH.sub.2SiMe.sub.2NMe- .sub.2 as a peak
at 188 mu (parent ion of 232 mu minus (Me).sub.2N of 44 mu) from
the coupling of the ligand system in the precursor
[--CuNMe.sub.2SiMe.sub.2CH.sub.2CuNMe.sub.2SiMe.sub.2CH.sub.2--] as
it releases copper metal in the CVD process.
[0153] The essence of the above synthesis is metallation of a
methyl group alpha to silicon in dimethylaminotrimethylsilane
followed by reaction with a copper (+1) species The resulting
reaction mixture is then filtered, if necessary, to remove any
by-product precipitates and then sublimed to yield the final
product. In some instances it may be possible to sublime the final
product directly from the crude reaction mixture.
[0154] Metallation of the dimethylaminotrimethylsilane can be
accomplished in many ways and a wide range of copper (+1) reagents
can be selected for reaction with it in the course of pursuing
alternative synthetic routes to complexes of the type[1] as shown
above. For example, in the case of preparing
[--CuNMe.sub.2SiMe.sub.2CH.sub.2CuNMe.sub.2SiMe.sub.2CH.sub.2--- ],
dimethylaminotrimethylsilane can be effectively metallated by first
forming a dimethylaminohalomethyldimethylsilane and reacting it
with a metal such as, but not limited to, magnesium, lithium,
aluminum, sodium, potassium, cesium, rubidium. Alternatively, the
dimethylaminohalomethyldi- methylsilane can be reacted with an
organometallic species to undergo a metal/halogen to generate the
metallated dimethylaminotrimethylsilane species. Alternatively,
dimethylaminotrimethylsilane can be deprotonated using an
organometallic reagent. Alternatively, the metallated
dimethylaminotrimethylsilane species can be generated
electrochemically. Suitable copper (+1) sources for which to react
the thus metallated dimethylaminotrimethylsilane include, but are
not limited to, copper halides, copper acetate, copper
trifuoroacetate, copper triflate, copper alkoxides, copper amides,
copper organometallics, copper hexafluorophosphate, copper
tetrafluoroborate or other suitable copper.sup.(+1) compounds. The
final product may be purified by sublimation, distillation,
recrystallization, selective reversible absorbtion, selective and
reversible adduct formation with a suitable coordinating medium,
column chromatography using a chromatographic medium that is benign
towards the organometallic copper compound product.
[0155] The general principles of the above alternative syntheses
can also be expanded to include dialkylaminotrialkylsilane species
in general in addition to the syntheses listed below, and metals
other than copper can be used to prepare the final metal
complex.
[0156] Other Structure Type #1 compounds may be prepared using
analogous syntheses.
Synthesis of a Compound of Structure Type #2 Compounds
[0157] Dimethyldichlorosilane (1 mole) can be dissolved in one
liter of tetrahydrofuran under an atmosphere of nitrogen, to which
one mole of lithiummethylamide in one liter of terahydrofuran can
be slowly added. The resulting mixture can be stirred overnight,
then all volatiles can be vacuum transferred off and fractionally
distilled under an atmospheric pressure of nitrogen to give
methylaminodimethylchlorosilane. One half mole of
methylaminodimethylchlorosilane can be then dissolved in one liter
of tetrahydrofuran under an atmosphere of nitrogen, to which
lithiumdimethylamide as a suspension in hexane can be slowly added.
The resulting solution can be stirred overnight at room
temperature, all volatiles can be vacuum transferred off, and the
resulting mixture can be fractionally distilled to give the product
dimethylaminomethylaminodimeth- ylsilane.
[0158] One tenth of a mole of
dimethylaminomethylaminodimethylsilane can be then suspended in 100
ml tetrahydrofuran under a blanket of nitrogen, and one tenth of a
mole of normal-butyl lithium (nBuLi) in hexane can be added over 10
minutes. The resulting solution can be cooled to zero degrees
centigrade, and one tenth of a mole of copper chloride can be added
over 1 hour. The resulting mixture would be allowed to warm to room
temperature for 1 hour, then filtered. The filtrate can be stripped
of solvent and heated under vacuum to distill out the product
[--Cu--NMe2SiMe2NMe--Cu--NMe2SiMe2NMe--]
Synthesis of a Compound of Structure Type #3 Compounds
[0159] One mole of diethyidichlorosilane can be dissolved in one
liter of tetrahydrofuran, or similar solvent, under an atmosphere
of nitrogen, and one mole of lithium dimethylamide can be slowly
added with stirring over a one hour period, then stirred overnight.
All of the volatiles can be vacuum transferred off and fractionally
distilled to yield the product, dimethylaminodiethylchlorosilane.
This product can be dissolved in tetrahydrofuran, or similar
solvent, under a nitrogen atmosphere. One mole of water can be
dissolved in 100 ml of tetrahydrofuran, or similar solvent, and can
be added slowly over a one hour period at zero degrees centigrade.
The resulting mixture can be filtered, and the filtrate
fractionally distilled to give the product,
dimethylaminodiethylsilanol. One equivalent of this product can be
dissolved in tetrahydrofuran, or in a similar solvent, and treated
with one equivalent of n-butyl lithium solution. The mixture can be
cooled to zero degrees centigrade, and one equivalent of copper
chloride can be added over 30 minutes. The mixture would be allowed
to warm to room temperature, filtered, solvent stripped away, and
the resulting mixture can be heated under vacuum to distill out the
product, [Cu--NMe2--SiEt2--O--Cu--NMe2--SiEt2--O--Cu--].
Synthesis of a Compound of Structure Type #4.
[0160] Dimethylamino-iodomethylmethane can be synthesized using
standard organic synthetic techniques. One equivalent of this
compound can be then dissolved in tetrahydrofuran, or a similar
solvent, and can be reacted with one equivalent of magnesium and
allowed to stir overnight. One equivalent of dioxane can be added
and after 30 minutes the mixture can be filtered. This solution can
be cooled to zero degrees celsius and cuprous chloride, or other
suitable cuprous compound can be slowly added over one hour. This
mixture can be allowed to stir at room temperature for one hour.
The solvent can be vacuum stripped off, and the resulting solid can
be heated under vacuum to distill out the product as
[--Cu--NMe2--CH2--CH2--Cu--NMe2--CH2--CH2--] Other Structure Type
#4 compounds may also be prepared using analogous syntheses.
Synthesis of a Compound of Structure Type #5.
[0161] N-dimethylamino-N'-methlyaminodimethylmethane can be
synthesized using standard organic synthetic techniques. One
equivalent of this compound can be dissolved in tetrahydrofuran, or
a similar solvent, cooled to -78.degree. C. and one equivalent of
nBuLi can be added. The mixture can be allowed to warm to room
temperature and stirred overnight. To this mixture one equivalent
of cuprous chloride or similar cuprous reagent can be slowly added
over one hour, and the mixture can beallowed to stir at room
temperature for one hour. The solvent can be vacuum stripped off,
and the resulting solid can be heated under vacuum to distill out
the product as [--Cu--NMe2--CMe2--NMe--Cu--NMe2--CMe2--NMe--]- .
Other Structure Type #4 compounds may be prepared using analogous
syntheses.
Synthesis of a Compound of Structure Type #6 .
[0162] Dimethylaminomethanol can be synthesized using standard
organic synthetic techniques. One equivalent of this compound can
be dissolved in tetrahydrofuran, or a similar solvent, cooled to
zero degrees celsius and can be reacted with on equivalent of
sodium hydride or similar deprotonating agent. This mixture can be
allowed to warm to room temperature and stirred overnight. To this
mixture one equivalent of cuprous chloride or similar cuprous
reagent can be slowly added over one hour, and the mixture allowed
to stir at room tempertaure for one hour. The solvent can be vacuum
stripped off and the resulting solid can be heated under vacuum to
distill out the product as [--Cu--NMe2--CH2--O--Cu-
--NMe2--CH2--O--]. Other Structure Type #6 compounds may be
prepared using analogous syntheses.
Synthesis of a Compound of Structure Type #7
[0163] t-Butoxychloromethyldimethylsilane can be synthesized using
standard organic synthetic techniques. One equivalent of this
compound can be dissolved in tetrahydrofuran, or a similar solvent,
and can be reacted with one equivalent of magnesium and can be
allowed to stir overnight. One eqivalent of dioxane can be added,
and after 30 minutes, the mixture can be filtered. This solution
can be cooled to zero degrees celsius, and cuprous chloride, or
other suitable cuprous compound can be slowly added over one hour.
This mixture can be allowed to stir at room temperature for one
hour. The mixture can be filtered, and the solvent can be vacuum
stripped off from the filtrate. The resulting solid can be heated
under vacuum to distill out the product as [--Cu--(CH.sub.3).sub.3-
O--CH.sub.2--CH.sub.2--Cu--(CH.sub.3).sub.3O--CH.sub.2--CH.sub.2--].
Other Structure Type #7 compounds may also be prepared using
analogous syntheses.
Synthesis of a Compound of Structure Type #8
[0164] Methoxymethylaminodimethylsilane can be synthesised using
standard organic synthetic techniques. One equivalent of this
compound can be dissolved in tetrahydrofuran, or a similar solvent,
cooled to zero degrees celsius and can be reacted with one
equivalent of n-butyllithium or similar deprotonating agent. This
mixture can be allowed to warm to room temperature and can be
stirred overnight. To this mixture one equivalent of cuprous
chloride or similar cuprous reagent can be slowly added over one
hour, and the mixture can be allowed to stir at room temperature
for one hour. The mixture can be filtered, solvent can be vacuum
stripped from the filtrate and the resulting solid can be heated
under vacuum to distill out the product as
[--Cu--OMe--SiMe.sub.2--NMe--C- u--OMe--SiMe.sub.2--NMe--]. Other
Structure Type #8 compounds may be prepared using analogous
syntheses.
Synthesis of a Compound of Structure Type #9
[0165] Methoxydimethylsilanol can be synthesized using standard
organic synthetic techniques. One equivalent of this compound can
be dissolved in tetrahydrofuran, or a similar solvent, cooled to
zero degrees celsius and can be reacted with one equivalent of
sodium hydride or similar deprotonating agent. This mixture can be
allowed to warm to room temperature and can be stirred overnight.
To this mixture one equivalent of cuprous chloride or similar
cuprous reagent can be slowly added over one hour, and the mixture
can be allowed to stir at room temperature for one hour. The
mixture can be filtered, solvent can be vacuum stripped from the
filtrate and the resulting solid can be heated under vacuum to
distill out the product as
[--Cu--OMe--SiMe.sub.2--O--Cu--OMe--SiMe.sub.2- --O--]. Other
Structure Type #9 compounds may be prepared using analogous
syntheses.
Synthesis of a Compound of Structure Type #10
[0166] t-Butoxy-bromomethylmethane can be synthesized using
standard organic synthetic techniques. One equivalent of this
compound can be dissolved in tetrahydrofuran, or a similar solvent,
and can be reacted with one equivalent of magnesium and allowed to
stir overnight. One equivalent of dioxane can be added, and after
30 minutes, the mixture is filtered. This solution can be cooled to
zero degrees celsius and cuprous chloride, or other suitable
cuprous compound can be slowly added over one hour. This mixture
can be allowed to stir at room temperature for one hour. The
mixture can be filtered, and the solvent can be vacuum stripped off
from the filtrate. The resulting solid can be heated under vacuum
to distill out the product as
[--Cu--Ot--Bu--CH.sub.2--CH.sub.2--Cu--Ot--Bu--
-CH.sub.2--CH.sub.2--]. Other Structure Type #10 compounds may also
be prepared using analogous syntheses.
Synthesis of a Compound of Structure Type #11
[0167] Methoxymethylaminomethane can be synthesized using standard
organic synthetic techniques. One equivalent of this compound can
be dissolved in tetrahydrofuran, or a similar solvent, cooled to
zero degrees celsius and can be reacted with one equivalent of
n-butyllithium or similar deprotonating agent. This mixture can be
allowed to warm to room temperature and can be stirred overnight.
To this mixture one equivalent of cuprous chloride or similar
cuprous reagent can be slowly added over one hour, and the mixture
can be allowed to stir at room temperature for one hour. The
mixture can be filtered, solvent can be vacuum stripped from the
filtrate, and the resulting solid can be heated under vacuum to
distill out the product as
[--Cu--OMe--CH.sub.2--NMe--Cu--OMe--CH.sub.2--- NMe--]. Other
Structure Type #11 compounds may be prepared using analogous
syntheses.
Synthesis of a Compound of Structure Type #12
[0168] t-Butoxymethanol can be synthesized using standard organic
synthetic techniques. One equivalent of this compound can be
dissolved in tetrahydrofuran, or a similar solvent, cooled to zero
degrees celsius and can be reacted with one equivalent of sodium
hydride or similar deprotonating agent. This mixture can be allowed
to warm to room temperature and can be stirred overnight. To this
mixture one equivalent of cuprous chloride or similar cuprous
reagent can be slowly added over one hour, and the mixture can be
allowed to stir at room temperature for one hour. The mixture can
be filtered, solvent can be vacuum stripped from the filtrate and
the resulting solid can be heated under vacuum to distill out the
product as [--Cu--Ot--Bu--CH.sub.2--O--Cu--Ot--Bu--CH.sub- .2--O--]
Other Structure Type #12 compounds may be prepared using analogous
syntheses.
Synthesis of a Compound of Structure Type #13
[0169] Using standard boron chemistry synthetic techniques,
MeOB(Me)OH can be prepared. This compound can be dissolved in ether
or another suitable solvent under an atmosphere of nitrogen and can
be treated with one equivalent of sodium hydride or other suitable
deprotonating agent. This mixture can be treated with one
equivalent of copper chloride or other suitable cuprous source.
After a suitable reaction time, this mixture can be filtered, the
filtrate can be stripped of solvent, and the resulting material can
be heated under vacuum to distill out the product
[--Cu--OMe--BMe--O--Cu--OMe--BMe--O--]. Other Structure Type #13
compounds may be prepared using analogous syntheses.
Synthesis of a Compound of Structure Type #14
[0170] Using standard boron chemistry synthetic techniques,
MeOB(Me)NMeH can be prepared. This compound can be dissolved in
ether or another suitable solvent under an atmosphere of nitrogen
and can be treated with one equivalent of sodium hydride or other
suitable deprotonating agent. This mixture can be treated with one
equivalent of copper chloride or other suitable cuprous source.
After a suitable reaction time, this mixture can be filtered, the
filtrate can be stripped of solvent and the resulting material can
be heated under vacuum to distill out the product
[--Cu--OMe--BMe--NMe--Cu--OMe--BMe--NMe--]. Other Structure Type
#14 compounds may be prepared using analogous syntheses.
Synthesis of a Compound of Structure Type #15
[0171] Using standard Boron chemistry synthetic techniques,
HOB(Me)NMe.sub.2 can be prepared. This compound can be dissolved in
ether or another suitable solvent under an atmosphere of nitrogen
and can be treated with one equivalent of sodium hydride or other
suitable deprotonating agent. This mixture can be treated with one
equivalent of copper chloride or other suitable cuprous source.
After a suitable reaction time this mixture can be filtered, the
filtrate can be stripped of solvent and the resulting material
heated under vacuum to distill out the product
[--Cu--O--BMe--NMe.sub.2--Cu--O--BMe--NMe.sub.2--]. Other Structure
Type #15 compounds may be prepared using analogous syntheses.
Synthesis of a Compound of Structure Type #16
[0172] Using standard Boron chemistry synthetic techniques,
HMeNB(Me)NMe.sub.2 can be prepared. This compound can be dissolved
in ether or another suitable solvent under an atmosphere of
nitrogen and can be treated with one equivalent of sodium hydride
or other suitable deprotonating agent. This mixture can be treated
with one equivalent of copper chloride or other suitable cuprous
source. After a suitable reaction time, this mixture can be
filtered, the filtrate can be stripped of solvent and the resulting
material can be heated under vacuum to distill out the product
[--Cu--NMe--BMe--NMe.sub.2--Cu--NMe--BMe--NMe.sub- .2--]. Other
Structure Type #16 compounds may be prepared using analogous
syntheses.
Synthesis of a Compound of Structure Type #17
[0173] Using standard Boron chemistry synthetic techniques,
MeO--B(Me)CH.sub.2Br can be prepared. This compound can be
dissolved in ether or another suitable solvent under an atmosphere
of nitrogen and can be treated with one equivalent of magnesium.
This mixture can be allowed to stir overnight, then can be treated
with one equivalent of dioxane and can be filtered. To this
filtrate, one equivalent of copper chloride or other suitable
cuprous source can be added. After a suitable reaction time, this
mixture can be filtered, the filtrate can be stripped of solvent
and the resulting material can be heated under vacuum to distill
out the product
[--Cu--OMe--BMe--CH.sub.2--Cu--OMe--BMe--CH.sub.2--]. Other
Structure Type #17 compounds may be prepared using analogous
syntheses.
Synthesis of a Compound of Structure Type #18
[0174] Using standard Boron chemistry synthetic techniques,
Me.sub.2N--B(Me)CH.sub.2Br can be prepared. This compound can be
dissolved in ether or another suitable solvent under an atmosphere
of nitrogen and can be treated with one equivalent of magnesium.
This mixture can be allowed to stir overnight, then can be treated
with one equivalent of dioxane and can be filtered. To this
filtrate, one equivalent of copper chloride or other suitable
cuprous source can be added. After a suitable reaction time, this
mixture can be filtered, the filtrate can be stripped of solvent
and the resulting material can be heated under vacuum to distill
out the product [--Cu--NMe.sub.2--BMe--CH.-
sub.2--Cu--NMe.sub.2--BMe--CH.sub.2--]. Other structure type #18
compounds may be prepared using analogous syntheses.
[0175] Within each of the structure types shown above there are the
groups 1, 2 and 3 that can bear different substituents. In a
typical synthesis, a complex is designed by selecting which
substituted groups 1,2 and 3 will comprise the ligand and after it
is synthesized and complexed to copper or another metal, a discreet
compound is formed. However, it may be advantageous to select two
or more different patterns of substituion within the groups to
yield two or more different ligands as, as a mixture these ligands
are complexed to copper or other metal to create a mixture of
copper or other metal compounds. Since there are two ligands and
two copper centers per molecule of final product, if ligands L1 and
L2 constitute the mixture of ligands which is complexed to copper,
then a mixture of three copper complexes will form, i.e.,
Cu.sub.2(L1).sub.2, Cu.sub.2(L1)(L2), and Cu.sub.2(L2)(L2).
Similarly, a mixture of three different ligands will yield a
mixture of copper complexes described as Cu.sub.2(L1).sub.2,
Cu.sub.2(L2).sub.2, Cu.sub.2(L3).sub.2, Cu.sub.2(L1)(L2),
Cu.sub.2(L2)(L3) and Cu.sub.2(L1)(L3). The advantage of such
mixtures is that they can be manifest as liquids which, under
certain circumstances, may offer advantages in vapor delivery,
especially by the process of direct liquid injection inthe CVD or
ALD process.
[0176] The present invention has been set forth with regard to
several preferred embodiments, but the full scope of the present
invention should be ascertained from the claims which follow.
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