U.S. patent application number 14/596037 was filed with the patent office on 2015-05-21 for methods of forming insulative elements.
The applicant listed for this patent is Micron Technology, Inc.. Invention is credited to Vassil Antonov, Vishwanath Bhat, Chris Carlson, Matthew N. Rocklein, Jennifer K. Sigman, Bhaskar Srinivasan.
Application Number | 20150140773 14/596037 |
Document ID | / |
Family ID | 46753510 |
Filed Date | 2015-05-21 |
United States Patent
Application |
20150140773 |
Kind Code |
A1 |
Antonov; Vassil ; et
al. |
May 21, 2015 |
METHODS OF FORMING INSULATIVE ELEMENTS
Abstract
Methods of forming an insulative element are described,
including forming a first metal oxide material having a first
dielectric constant, forming a second metal oxide material having a
second dielectric constant different from the first, and heating at
least portions of the structure to crystallize at least a portion
of at least one of the first dielectric material and the second
dielectric material. Methods of forming a capacitor are described,
including forming a first electrode, forming a dielectric material
with a first oxide and a second oxide over the first electrode, and
forming a second electrode over the dielectric material. Structures
including dielectric materials are also described.
Inventors: |
Antonov; Vassil; (Boise,
ID) ; Sigman; Jennifer K.; (Boise, ID) ; Bhat;
Vishwanath; (Boise, ID) ; Rocklein; Matthew N.;
(Boise, ID) ; Srinivasan; Bhaskar; (Plano, TX)
; Carlson; Chris; (Nampa, ID) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Micron Technology, Inc. |
Boise |
ID |
US |
|
|
Family ID: |
46753510 |
Appl. No.: |
14/596037 |
Filed: |
January 13, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
13038605 |
Mar 2, 2011 |
8940388 |
|
|
14596037 |
|
|
|
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Current U.S.
Class: |
438/381 ;
438/763 |
Current CPC
Class: |
H01G 4/1272 20130101;
H01L 28/40 20130101; Y10T 428/2495 20150115; H01G 4/1254 20130101;
H01L 21/225 20130101; H01G 4/1236 20130101; H01G 4/1209 20130101;
H01L 21/02172 20130101; H01G 4/306 20130101; H01G 4/33 20130101;
H01G 4/1218 20130101; H01L 21/02356 20130101 |
Class at
Publication: |
438/381 ;
438/763 |
International
Class: |
H01L 49/02 20060101
H01L049/02; H01L 21/225 20060101 H01L021/225; H01L 21/02 20060101
H01L021/02 |
Claims
1. A method of forming an insulative element, comprising: forming a
first metal oxide material having a first dielectric constant on a
substrate; forming a second metal oxide material having a second
dielectric constant different from the first dielectric constant
over at least a portion of the first metal oxide material; and
heating at least one of the first metal oxide material and the
second metal oxide material to crystallize at least a portion of
the at least one of the first metal oxide material and the second
metal oxide material.
2. The method of claim 1, wherein forming a second metal oxide
material having a second dielectric constant different from the
first dielectric constant comprises forming a second metal oxide
material having a second dielectric constant greater than the first
dielectric constant.
3. The method of claim 1, wherein heating at least one of the first
metal oxide material and the second metal oxide material to
crystallize at least a portion of the at least one of the first
metal oxide material and the second metal oxide material comprises
crystallizing substantially all of the first metal oxide
material.
4. The method of claim 1, further comprising forming a dielectric
material having a third dielectric constant different than the
first and second dielectric constants in contact with at least one
of the first metal oxide material and the second metal oxide
material.
5. The method of claim 1, wherein forming a first metal oxide
material having a first dielectric constant on a substrate
comprises forming the first metal oxide material on an
electrode.
6. The method of claim 1, wherein heating at least one of the first
metal oxide material and the second metal oxide material comprises
heating the first metal oxide material and the second metal oxide
material after forming both the first metal oxide material and the
second metal oxide material.
7. The method of claim 6, wherein heating the first metal oxide
material and the second metal oxide material after forming both the
first metal oxide material and the second metal oxide material
comprises subjecting the first and second metal oxide materials to
heat during at least one deposition or diffusion act occurring
after forming the first and second metal oxide materials.
8. A method of forming an insulative element, comprising: forming a
substantially crystalline dielectric material on a substrate;
forming a metal oxide material having a dielectric constant greater
than a dielectric constant of the substantially crystalline
dielectric material over the substantially crystalline dielectric
material; and heating the substantially crystalline dielectric
material and the metal oxide material to induce diffusion of at
least some dopants of the metal oxide material into the
substantially crystalline dielectric material.
9. The method of claim 8, wherein forming a substantially
crystalline dielectric material on a substrate comprises: forming a
substantially amorphous metal oxide material on the substrate; and
annealing the substantially amorphous metal oxide material to
crystallize a substantial portion of the substantially amorphous
metal oxide material.
10. The method of claim 9, wherein annealing the substantially
amorphous metal oxide material to crystallize a substantial portion
of the substantially amorphous metal oxide comprises annealing the
substantially amorphous metal oxide material at a temperature of
from about 300.degree. C. to about 700.degree. C.
11. The method of claim 8, wherein forming a substantially
crystalline dielectric material comprises forming the substantially
crystalline dielectric material having a thickness in the range of
from about 30 .ANG. to about 80 .ANG..
12. The method of claim 8, wherein forming a metal oxide material
having a dielectric constant greater than a dielectric constant of
the substantially crystalline dielectric material over the
substantially crystalline dielectric material comprises forming the
metal oxide material having a thickness of from about 5 .ANG. to
about 30 .ANG..
13. The method of claim 12, further comprising forming another
oxide material at least partially between the substantially
crystalline dielectric material and the metal oxide material, the
another oxide material having a composition different than each of
the substantially crystalline dielectric material and the metal
oxide material.
14. The method of claim 13, wherein forming another oxide material
comprises forming another oxide material having a thickness of from
about 1 monolayer to about 5 .ANG..
15. A method of forming a capacitor, comprising: forming a first
electrode; forming a dielectric material over and in contact with
the first electrode, comprising: forming a first oxide having a
first dielectric constant; forming a second oxide having a second
dielectric constant greater than the first dielectric constant over
the first oxide; heating at least one of the first oxide and the
second oxide to at least partially crystallize at least one of the
first oxide and the second oxide; and forming a second electrode
over the dielectric material.
16. The method of claim 15, wherein forming a first oxide having a
first dielectric constant comprises: forming a first portion of the
first oxide in an amorphous state; annealing the first portion of
the first oxide to crystallize substantially all of the first
portion of the first oxide; and forming a second portion of the
first oxide in an amorphous state over the annealed first portion
of the first oxide.
17. The method of claim 16, further comprising diffusing dopants of
the second oxide into the crystallized first portion of the first
oxide.
18. The method of claim 1, wherein heating at least one of the
first metal oxide material and the second metal oxide material to
crystallize at least a portion of the at least one of the first
metal oxide material and the second metal oxide material comprises
heating the first metal oxide material to crystallize at least a
portion of the first metal oxide material.
19. The method of claim 18, further comprising dispersing dopants
of the second metal oxide material in the crystallized at least a
portion of the first metal oxide material.
20. The method of claim 19, further comprising forming a dielectric
material having a material composition different than the first
metal oxide material and the second metal oxide material in contact
with at least one of the first metal oxide material and the second
metal oxide material.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a divisional of U.S. patent application
Ser. No. 13/038,605, filed Mar. 2, 2011, pending, the disclosure of
which is hereby incorporated herein in its entirety by this
reference.
TECHNICAL FIELD
[0002] Embodiments of the present disclosure relate to forming an
insulative element having a high dielectric constant (k) and a low
leakage current. Specific embodiments of the present disclosure
relate to forming the insulative element having a high k and low
leakage current from a metal oxide material doped with another,
different metal oxide material.
BACKGROUND
[0003] Capacitors are the basic energy storage devices in random
access memory devices, such as dynamic random access memory
("DRAM") devices. Capacitors include two conductors, such as
parallel metal or polysilicon plates, which act as electrodes. The
electrodes are insulated from each other by a dielectric material.
With the continual shrinkage of microelectronic devices, such as
capacitors, the materials traditionally used in integrated circuit
technology are approaching their performance limits. Silicon
dioxide ("SiO.sub.2") has frequently been used as the dielectric
material in capacitors. However, with smaller and smaller capacitor
area, SiO.sub.2 cannot be thinned to provide sufficient capacitance
while maintaining low leakage. This deficiency has lead to a search
for improved dielectric materials. High quality, thin dielectric
materials possessing higher dielectric constants (k) than SiO.sub.2
are of interest to the semiconductor industry. Examples of
materials having dielectric constants (k) greater than SiO.sub.2
include hafnium oxide ("HfO.sub.2"), zirconium oxide ("ZrO.sub.2"),
and strontium titanate ("SrTiO.sub.3"). In general, dielectric
materials with a higher dielectric constant also exhibit higher
leakage currents. Dielectric materials are typically formed by
chemical vapor deposition ("CVD") or atomic layer deposition
("ALD"). However, CVD is unable to provide good step coverage and
film stoichiometry in high aspect ratio containers. Therefore, CVD
is not useful to fill high aspect ratio containers. While ALD
provides good step coverage, current CVD and ALD techniques each
produce high-k dielectric materials that have high leakage.
[0004] To produce a capacitor, a bottom electrode is formed on a
semiconductor substrate and a dielectric material is deposited over
the bottom electrode. The bottom electrode and the dielectric
material are annealed, and a top electrode is formed over the
dielectric material. The dielectric material is typically annealed
before the top electrode is formed.
[0005] U.S. Pat. No. 7,101,754 discloses forming mixed dielectric
films, composed of a high-k dielectric to produce a certain level
of capacitance and a relatively lower-k dielectric to control
leakage current, on a conductor material. The dielectric film
having a composition of SiO.sub.2 and TiO.sub.2 made by a sol-gel
process is applied onto a substrate using a spin-on technique. The
discontinuous layer is annealed in the presence of a reactive
species so that exposed portions of the conductor material are
converted to an insulating material. However, forming the mixed
dielectric films is difficult due to the, oftentimes, conflicting
deposition requirements of the high-k dielectric and the relatively
lower-k dielectric.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 shows a partial cross-sectional view of an embodiment
of an insulative element according to the present disclosure.
[0007] FIG. 2 shows a partial cross-sectional view of a second
embodiment of an insulative element according to the present
disclosure.
[0008] FIG. 3 shows a partial cross-sectional view of a third
embodiment of an insulative element according to the present
disclosure.
[0009] FIG. 4 shows a partial cross-sectional view of an embodiment
of a capacitor including an insulative element as in FIG. 1, FIG.
2, or FIG. 3.
[0010] FIGS. 5A through 5D illustrate an embodiment of a process
for forming an insulative element according to the present
disclosure, such as the insulative element of FIG. 1.
[0011] FIGS. 6A through 6E illustrate an embodiment of a process
for forming an insulative element according to the present
disclosure, such as the insulative element of FIG. 2.
[0012] FIGS. 7A through 7F illustrate an embodiment of a process
for forming an insulative element according to the present
disclosure, such as the insulative element of FIG. 3.
DETAILED DESCRIPTION
[0013] The following description provides specific details, such as
material types, material thicknesses, and processing conditions in
order to provide a thorough description of embodiments of the
present invention. However, a person of ordinary skill in the art
will understand that the embodiments of the present invention may
be practiced without employing these specific details. Indeed, the
embodiments of the present invention may be practiced in
conjunction with conventional fabrication techniques employed in
the industry.
[0014] As used herein, the term "amorphous" means and includes
without a real or apparent crystalline form, such as
non-crystalline or at least substantially non-crystalline.
[0015] As used herein, the term "crystalline" means and includes a
monocrystalline or polycrystalline chemical structure or phase. A
crystalline phase may include one or more molecules of another
material.
[0016] As used herein, terms such as "first" and "second" are used
to merely differentiate between structures, methods, materials, or
other components, and do not necessarily refer to any particular
sequence.
[0017] As used herein, the term "forming" means and includes any
method of creating, building, or depositing a material. For
example, forming may be accomplished by atomic layer deposition
(ALD), chemical vapor deposition (CVD), sputtering, spin-coating,
diffusing, depositing, growing, or any other forming technique
known in the art of semiconductor fabrication.
[0018] As used herein, the term "substantially" means and includes
mostly, essentially, fully, or entirely. By way of example, the
phrase "a substantially crystalline material" may refer to a
material with a portion in a crystalline state, the portion in the
range of from about 90% by volume up to and including about 100% by
volume of the material, and a remaining portion (i.e., about 10% to
about 0% by volume, respectively) in an amorphous state.
[0019] As used herein, the term "substrate" refers to any
supporting base material, structure, or construction. By way of
example and not limitation, a substrate may be a semiconductor
substrate, a base semiconductor layer or structure on a supporting
structure, a metal or polysilicon electrode, or a semiconductor
substrate having one or more layers, structures, or regions formed
thereon. In some embodiments, a semiconductor substrate may have at
least a portion thereof doped so as to be conductive, such as an
n-doped or p-doped silicon substrate.
[0020] As used herein, the term "structure" refers to a layer or
film, or to a nonplanar mass, such as a three-dimensional mass,
having a substantially nonplanar configuration. The term
"structure" also may refer to a mass formed of more than one layer,
film, non-planar mass, or combination thereof.
[0021] Some embodiments of insulative elements including dielectric
materials having a high dielectric constant (k) and a low leakage
current are shown in FIGS. 1 through 4 and are described as
follows. Similar structures or components in the various drawings
may retain the same or similar numbering for the convenience of the
reader; however, the similarity in numbering does not mean that the
structures or components are necessarily identical in size,
composition, configuration, or any other property. The insulative
elements include a first dielectric material and a second
dielectric material. During fabrication of the insulative element,
the second dielectric material may be formed as a capping material
over the first dielectric material and may function as a dopant
source for the first dielectric material. Upon exposure to heat,
the second dielectric material may form an alloy phase with the
first dielectric material. In combination, the first dielectric
material and the second dielectric material may form a dielectric
material of the insulative element.
[0022] In some embodiments, an insulative element 10, as shown in
any of FIGS. 1 through 3, may be used as a component of a
semiconductor device. By way of example, the insulative element 10
may be useful as a dielectric material in a capacitor, such as in a
planar cell, trench cell, (e.g., double sidewall trench capacitor),
or stacked cell (e.g., crown, V-cell, delta cell, multi-fingered,
or cylindrical container stacked capacitor). The insulative element
10 may also be useful as a gate dielectric in a transistor, or as
an insulating material between conductive components or portions
thereof that are to be isolated electrically. While the intended
uses of the insulative elements 10 are described herein, any
application where high-k dielectric materials may be desirable is
contemplated by the present disclosure. The insulative element 10
may be used in a metal-insulator-metal (MIM) capacitor or a
metal-insulator-semiconductor (MIS) capacitor or gate stack. The
insulative element 10 may provide a high dielectric constant (k)
and a low leakage current to a semiconductor device that includes
the insulative element 10.
[0023] As shown in FIG. 1, some embodiments of the present
disclosure include an insulative element 10 having a high
dielectric constant (k) with low leakage current. The insulative
element 10 may include a first dielectric material 20 and a second
dielectric material 22 over a substrate 24. In some embodiments,
the substrate 24 may be or include a conductive material, such as
at least one of polysilicon and a metal including, but not limited
to, platinum, aluminum, iridium, rhodium, ruthenium, titanium,
tantalum, tungsten, alloys thereof, and combinations thereof. If
the insulative element 10 is to be used in a MIM capacitor, the
substrate 24 may be a metal electrode. If the insulative element 10
is to be used in a MIS capacitor or gate stack, the substrate 24
may be silicon.
[0024] The first dielectric material 20 and the second dielectric
material 22 may each include at least one metal oxide material,
with the first dielectric material 20 and the second dielectric
material 22 including different metal oxide materials that have
different dielectric constants (k). To provide the different
dielectric constants (k), the metal oxide materials of the first
dielectric material 20 and the second dielectric material 22 may
differ in the elements present therein or in the stoichiometry of
the elements present therein. By way of example and not limitation,
the metal oxide material of the first dielectric material 20 may
include one or more of a hafnium oxide (Hf.sub.yO.sub.x, such as
HfO.sub.2), a zirconium oxide (Zr.sub.yO.sub.x, such as ZrO.sub.2),
an aluminum oxide (Al.sub.yO.sub.x, such as Al.sub.2O.sub.3), a
strontium oxide (Sr.sub.yO.sub.x, such as SrO), a titanium oxide
(Ti.sub.yO.sub.x, such as TiO.sub.2), a niobium oxide
(Nb.sub.yO.sub.x, such as Nb.sub.2O.sub.5), a tantalum oxide
(Ta.sub.yO.sub.x, such as Ta.sub.2O.sub.5), and a rare earth oxide,
wherein each of x and y is an integer greater than or equal to 1.
As used herein, the phrase "rare earth oxide" refers to an oxide of
a rare earth element, including the elements scandium (Sc), yttrium
(Y), lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium
(Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium
(Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er),
thulium (Tm), ytterbium (Yb), and lutetium (Lu). The first
dielectric material 20 may also include one or more of a silicon
oxide (Si.sub.yO.sub.x, such as SiO.sub.2), a germanium oxide
(Ge.sub.yO.sub.x, such as GeO.sub.2), and an oxynitride (such as
SiO.sub.xN.sub.y or HfO.sub.xN.sub.y).
[0025] The second dielectric material 22 may include a metal oxide
or combinations of metal oxides different from the first dielectric
material 20. The second dielectric material 22 may include one or
more of the metal oxides described above for the first dielectric
material 20, such as at least one of HfO.sub.2, ZrO.sub.2,
Al.sub.2O.sub.3, SrO, TiO.sub.2, Nb.sub.2O.sub.5, Ta.sub.2O.sub.5,
and a rare earth oxide. The second dielectric material 22 may also
include one or more of SiO.sub.2, GeO.sub.2, and an oxynitride. The
composition of the second dielectric material 22 may differ from
the composition of the first dielectric material 20 in that the
second dielectric material 22 may include different elements than
the first dielectric material 20 or, if the same elements are
present, a different stoichiometry of the respective elements. In
some embodiments, the second dielectric material 22 may include one
or more of the same metal oxides as the first dielectric material
20, in addition to another metal oxide material. For example, where
the first dielectric material 20 includes primarily HfO.sub.2, the
second dielectric material 22 may include HfO.sub.2 in combination
with another metal oxide, such as TiO.sub.2. Therefore, the overall
composition of the second dielectric material 22 may differ from
the overall composition of the first dielectric material 20,
although some similarity in composition may be present.
[0026] In some embodiments, the first dielectric material 20
includes one or more of HfO.sub.2 and ZrO.sub.2 and, optionally,
one or more of Al.sub.2O.sub.3 and SiO.sub.2, and the second
dielectric material 22 includes one or more of SrO, TiO.sub.2,
Nb.sub.2O.sub.5, Ta.sub.2O.sub.5, and the rare earth oxide. For
example, the first dielectric material 20 may include at least one
of HfO.sub.2 and ZrO.sub.2 and at least one of SiO.sub.2 and
Al.sub.2O.sub.3, the latter of which, if present, may account for a
relatively small proportion of the first dielectric material 20.
The second dielectric material 22 may, optionally, also include one
or more of SiO.sub.2, Al.sub.2O.sub.3, ZrO.sub.2, and another
material, in addition to the one or more of SrO, TiO.sub.2,
Nb.sub.2O.sub.5, Ta.sub.2O.sub.5, and the rare earth oxide. The
first dielectric material 20 may also include at least a portion
(such as the portion closest to the second dielectric material 22)
within which molecules of the second dielectric material 22 are
dispersed. In other words, the portions of the first dielectric
material 20 may be "doped" with metal oxide molecules of the second
dielectric material 22. As used herein, the term "dispersed" means
and includes located within, and may refer to varying
concentrations across a region (i.e., heterogeneous) or may refer
to a substantially constant concentration across a region (i.e.,
homogeneous). Molecules dispersed in a structure or material may
refer to molecules located at various positions in the structure or
material. For example, dispersed molecules may include molecules of
the second dielectric material 22 incorporated into the crystalline
phase of the first dielectric material 20, located between the
grain boundaries of the crystalline phase of the first dielectric
material 20, located in an amorphous portion of the first
dielectric material 20, or combinations thereof.
[0027] The metal oxide material of the second dielectric material
22 may be selected to have a dielectric constant (k) higher than
the dielectric constant (k) of the metal oxide material of the
first dielectric material 20. For example, if the first dielectric
material 20 includes primarily HfO.sub.2, which has a dielectric
constant (k) of about 25, the second dielectric material 22 may
include primarily Nb.sub.2O.sub.5, which has a dielectric constant
(k) of about 41. However, the selection of metal oxide materials of
the first and second dielectric materials 20, 22 may be altered
such that the metal oxide material of the second dielectric
material 22 has a dielectric constant (k) lower than the dielectric
constant (k) of the metal oxide material of the first dielectric
material 20. The difference in dielectric constant (k) between the
first and second dielectric materials 20, 22 may be less than about
5.
[0028] In some embodiments, a material forming a majority of a
region or material may be referred to as a matrix, and a material
forming a smaller portion of the region may be referred to as a
dopant. The matrix may have the dopant(s) dispersed therein. By way
of example, the first dielectric material may function as the
matrix while the metal oxide of the second dielectric material may
function as the dopant(s).
[0029] In some embodiments, there may be no clear interface or
boundary between the first dielectric material 20 and the second
dielectric material 22. For example, some regions of the first
dielectric material 20 may exhibit a relatively higher
concentration of metal oxide molecules from the second dielectric
material 22 and other regions of the first dielectric material 20
may exhibit a relatively lower concentration of metal oxide
molecules from the second dielectric material 22. However, for
convenience and clarity, the first and second dielectric materials
20, 22 are illustrated herein as having a distinct interface
between adjacent materials.
[0030] The first dielectric material 20 may be formed at a greater
thickness than the second dielectric material 22. For example, the
first dielectric material 20 may have a thickness of between about
30 Angstroms (.ANG.) and about 80 .ANG., and the second dielectric
material 22 may have a thickness of between about 5 .ANG. and about
30 .ANG.. The second dielectric material 22 may be sufficiently
thin such that its contribution to the total thickness of the
dielectric material 14 (the first dielectric material 20 and the
second dielectric material 22, see FIG. 4) is minimal compared to
its contribution to the dielectric constant of the first dielectric
material 20 and the second dielectric material 22. Depending on the
intended use of the insulative element 10, one or both of the first
and second dielectric materials 20, 22 may be thicker or thinner
than the ranges recited.
[0031] The first dielectric material 20 of the insulative element
10 may be substantially crystalline, although some portions of the
first dielectric material 20 may be amorphous. In some embodiments,
the second dielectric material 22 may be substantially crystalline.
However, in other embodiments, the second dielectric material may
be substantially amorphous. In some embodiments, at least a portion
of the metal oxides of the second dielectric material 22 may be
distributed in the first dielectric material 20. In other words, at
least some of the metal oxide molecules of the second dielectric
material 22 may be incorporated into or distributed within or
between the lattice or crystalline phase of the first dielectric
material 20. As described in more detail below, molecules of the
metal oxide of the second dielectric material 22 may diffuse into
the first dielectric material 20, doping the first dielectric
material 20 with the metal oxide of the second dielectric material
22. A crystalline dielectric material generally has a higher
dielectric constant (k) compared to the same dielectric material in
an amorphous phase or state. Thus, the dielectric constant (k) of
the insulative element 10 may be tailored by crystallizing none,
some, portions of, or substantially all of the first and second
dielectric materials 20, 22, for example.
[0032] The crystalline phase of one or both of the first and second
dielectric materials 20, 22 may be achieved by annealing one or
both of the metal oxide materials of the first and second
dielectric materials 20, 22. Additionally, the dispersion of
molecules of the second dielectric material 22 within the first
dielectric material 20 (also referred to as "doping" of the first
dielectric material 20) may be accomplished by annealing the metal
oxide material of the first and second dielectric materials 20, 22.
As used herein, "annealing" refers to subjecting to elevated
temperatures, or heating, for a period of time. A more detailed
description of annealing and crystallizing the metal oxide
materials is provided below. Annealing one or both of the metal
oxide materials of the first and second dielectric materials 20, 22
may provide the insulative element 10 having the higher k compared
to a so-called "mixed dielectric" in which a material including a
mixture of two dielectric materials is formed and then
annealed.
[0033] Referring now to FIG. 2, in some embodiments, one or more
additional materials may be present as a part of the insulative
element 10. For example, an additional dielectric material 26 may
be located between the first dielectric material 20 and the second
dielectric material 22. The additional dielectric material 26 may
function as a barrier material, preventing or reducing the
diffusion and dispersion of molecules of the second dielectric
material 22 across the additional dielectric material 26.
[0034] In some embodiments, the insulative element 10 may include
the additional dielectric material 26 located over the second
dielectric material 22 (i.e., on the side of the second dielectric
material 22 opposite the first dielectric material 20, shown by
dashed lines in FIG. 2 as additional dielectric material 26a) or
located between the substrate 24 and the first dielectric material
20 (shown by dashed lines in FIG. 2 as additional dielectric
material 26b), rather than or in addition to between the first and
second dielectric materials 20, 22. The additional dielectric
material 26 may modulate diffusion of the second dielectric
material 22 into the first dielectric material 20.
[0035] The additional dielectric material 26 may include one or
more of HfO.sub.2, SiO.sub.2, ZrO.sub.2, Al.sub.2O.sub.3,
GeO.sub.2, and a rare earth oxide. The additional dielectric
material 26 may have a different composition than the first
dielectric material 20, the second dielectric material 22, or both
the first and second dielectric materials 20, 22. In some
embodiments, the additional dielectric material 26 may include one
or more similar metal oxides to the metal oxide(s) of the first,
second, or first and second dielectric materials 20, 22. By way of
example and not limitation, in an embodiment where the first
dielectric material 20 includes primarily HfO.sub.2 and the second
dielectric material 22 includes primarily TiO.sub.2, the additional
dielectric material 26 may include primarily SiO.sub.2 or
Al.sub.2O.sub.3. The overall composition of the additional
dielectric material 26 may differ from the overall composition of
one or both of the first and second dielectric materials 20, 22,
although some similarity in composition may occur.
[0036] The additional dielectric material 26 may, in some
embodiments, have a thickness that is less than a thickness of the
first dielectric material 20. In some embodiments, the additional
dielectric material 26 may have a thickness that is less than both
a thickness of the first dielectric material 20 and a thickness of
the second dielectric material 22. By way of example and not
limitation, the dielectric material 26 may have a thickness in the
range of from about one monolayer to about 5 .ANG..
[0037] In some embodiments, the thickness of the additional
dielectric material 26 may not be clearly defined due to diffusion
of the additional dielectric material 26 into one or both of the
first dielectric material 20 and the second dielectric material 22.
In some embodiments, the first dielectric material 20 may include
at least portions (such as those closest to the second dielectric
material 22) wherein molecules of the metal oxides of the second
dielectric material 22 are dispersed. In other words, the portions
of the first dielectric material 20 may be "doped" with molecules
of the second dielectric material 22.
[0038] Referring now to FIG. 3, in some embodiments, the first
dielectric material 20 may have a first region 33 being at least
substantially free of molecules of the metal oxide material of the
second dielectric material 22, and a second region 34 including
molecules of the second dielectric material 22 dispersed therein. A
majority by volume of the first region 33 and a majority by volume
of the second region 34 of the first dielectric material 20 may
include the same dielectric material, although the second region 34
may additionally include a higher concentration of molecules of the
second dielectric material 22 dispersed therein than the first
region 33. In some embodiments, the first region 33 and the second
region 34 may each be substantially crystalline. In some
embodiments, the first region 33, the second region 34, and the
second dielectric material 22 may each be substantially
crystalline.
[0039] While embodiments of the insulative element 10 have been
described and illustrated with the first and second dielectric
materials 20, 22 having specific compositions and shown to be in
specific configurations, it is to be understood that these
descriptions may be altered. For example, a material with a
composition similar or identical to the second dielectric material
22 may be formed on a substrate 24 first, and a material with a
composition similar or identical to the first dielectric material
20 may be formed over the second dielectric material 22. In some
embodiments, overall properties (e.g., dielectric constant,
capacitance, leakage current) of the insulative element 10 may be
changed or tailored by altering the configuration of the first
dielectric material 20 and the second dielectric material 22.
[0040] Referring now to FIG. 4, some embodiments of the invention
include a semiconductor device structure 30 including a first
electrode 12, a second electrode 16, and dielectric material 14, at
least portions of which are located between the first electrode 12
and the second electrode 16. The first electrode 12, dielectric
material 14, and second electrode 16 may be collectively referred
to as a capacitor 18.
[0041] The first electrode 12 may be a conductive element, which
may include, for example, one or more of polysilicon and a metal,
including, but not limited to, platinum, aluminum, iridium,
rhodium, ruthenium, titanium, tantalum, tungsten, alloys thereof,
and combinations thereof. The dielectric material 14 may be formed
over the first electrode 12. The second electrode 16 may also be a
conductive element, which may likewise include, for example, one or
more of polysilicon and a metal, including, but not limited to,
platinum, aluminum, iridium, rhodium, ruthenium, titanium,
tantalum, tungsten, alloys thereof, and combinations thereof.
[0042] The dielectric material 14 may include one of the insulative
elements 10 illustrated and described in reference to FIGS. 1
through 3 above and, therefore, may include first and second
dielectric materials 20 and 22, which may, by way of example, have
a composition as described with reference to any of FIGS. 1 through
3 above or variations and equivalents thereof. For example, the
dielectric material 14 may include the first dielectric material 20
and the second dielectric material 22. The first dielectric
material 20 may be at least substantially crystallized and have a
first dielectric constant. The first dielectric material 20 may be
at least partially doped with the second dielectric 22 material
having a second dielectric constant.
[0043] Some embodiments of methods of forming insulative elements
10 or a semiconductor device structure 30, such as those shown in
FIGS. 1 through 4, are shown in FIGS. 5A through 7F and are
described as follows. First and second oxide materials 29, 32 may
be formed over a substrate 24 and the first and second oxide
materials 29, 32 annealed to modulate the interaction between the
matrix of the first oxide material 29 and the dopant of the second
oxide material 32. The first and second dielectric materials 20, 22
may be formed in this manner. The timing of the anneal in the
process flow may determine whether dopant interdiffusion is
promoted or inhibited. The timing of the anneal in the process flow
may provide the semiconductor device structure 30 having increased
k through enhanced diffusion of the dopant or decreased k by
hindering the diffusion of the dopant.
[0044] One embodiment of a method showing the formation of an
insulative element 10 (as shown in FIG. 1, for example) or a
capacitor is shown in FIGS. 5A through 5D. A first metal oxide
material 29 may be formed on a substrate 24, as shown in FIG. 5A.
By way of example and not limitation, the substrate 24 may be or
include a capacitor electrode, a portion of a transistor, a
semiconductive film, a doped portion of a semiconductor material,
any other structure whereon a metal oxide material may be formed,
or any combination thereof. The first metal oxide material 29 may
be substantially amorphous at formation. In some embodiments,
certain formation techniques, such as CVD, may produce sufficient
heat to cause the crystallization of one or more portions of the
first metal oxide material 29 upon formation. However, at least a
portion of the first metal oxide material 29 may remain amorphous
during the formation thereof.
[0045] By way of example and not limitation, the first metal oxide
material 29 may be formed to a thickness sufficiently thin to
enable small feature sizes of an integrated circuit to be formed
and to enable high capacitance (which is inversely related to the
distance from one electrode to another, i.e., the thickness of the
dielectric material 14, see FIG. 4). At the same time, the first
metal oxide material 29 may be formed to be of sufficient thickness
to reduce defects and undesirable properties, such as leakage
current, in the semiconductor device structure 30. By way of
example and not limitation, the first metal oxide material 29, as
formed, may have a thickness in the range of from about 30 .ANG. to
about 80 .ANG..
[0046] The first metal oxide material 29 may be formed from at
least one or more of HfO.sub.2, ZrO.sub.2, Al.sub.2O.sub.3, SrO,
TiO.sub.2, Nb.sub.2O.sub.5, Ta.sub.2O.sub.5, and a rare earth
oxide. The first metal oxide material 29 may also be formed to
include one or more of SiO.sub.2, GeO.sub.2, and an oxynitride. By
way of example and not limitation, the first metal oxide material
29 may be formed from one or more of HfO.sub.2 and ZrO.sub.2 and,
optionally, one or more of Al.sub.2O.sub.3, and SiO.sub.2.
[0047] A second metal oxide material 32 may be formed over the
first metal oxide material 29 or portions thereof. The second metal
oxide material 32 may be formed from a material(s) selected to have
a different dielectric constant (k) than the first metal oxide
material 29. For example, the second metal oxide material 32 may be
a material(s) selected to have a higher dielectric constant (k)
than the first metal oxide material 29. In some embodiments, at
least a substantial portion of the second metal oxide material 32
may be a material with a higher dielectric constant than the first
metal oxide material 29. By way of example, the second metal oxide
material 32 may be formed from one or more of SrO, TiO.sub.2,
Nb.sub.2O.sub.5, Ta.sub.2O.sub.5, and a rare earth oxide when the
first metal oxide material 29 is formed from one or more of
HfO.sub.2, ZrO.sub.2, SiO.sub.2, and Al.sub.2O.sub.3. Optionally,
the second metal oxide material 32 may also include a material(s)
having a relatively lower dielectric constant (k), such as, for
example, one or more of SiO.sub.2, Al.sub.2O.sub.3, ZrO.sub.2, and
HfO.sub.2.
[0048] The second metal oxide material 32 may be formed to be at
least substantially amorphous at formation. In some embodiments,
certain formation techniques, such as CVD, may produce sufficient
heat to cause the crystallization of some of the second metal oxide
material 32 at formation. However, at least a portion of the second
dielectric material 22 may remain amorphous during the formation
thereof.
[0049] The second metal oxide material 32 may be formed to be
sufficiently thin to limit its contribution to the total thickness
of the dielectric material 14. However, the second metal oxide
material 32 may have sufficient thickness to provide a doping
effect on the first metal oxide material 29. The doping may occur
when molecules of the second metal oxide material 32 diffuse or
migrate into the first metal oxide material 29. In other words, the
second metal oxide material 32 may be formed at a sufficient
thickness to provide an effective amount of material to dope the
first metal oxide material 29 to tailor the properties (e.g.,
dielectric constant (k) and leakage current) of the overall
insulative element 10 or semiconductor device structure 30. The
second metal oxide material 32 may have a thickness that is the
same or different than the thickness of the first metal oxide
material 29. In some embodiments, the thickness of the second metal
oxide material 32 may be less than the thickness of the first metal
oxide material 29. By way of example and not limitation, the second
metal oxide material 32 may have a thickness, as formed, in the
range of from about 5 .ANG. to about 30 .ANG..
[0050] In one embodiment, the first metal oxide material 29 is
Zr.sub.yO.sub.x and the second metal oxide material 32 is a mixture
of Zr.sub.yO.sub.x and Nb.sub.yO.sub.x. In one embodiment, the
first metal oxide material 29 is Zr.sub.yO.sub.x and the second
metal oxide material 32 is a mixture of Sr.sub.yO.sub.x and
Nb.sub.yO.sub.x. In one embodiment, the first metal oxide material
29 is Zr.sub.yO.sub.x and the second dielectric material 22 is a
mixture of Sr.sub.yO.sub.x, Nb.sub.yO.sub.x, and Ti.sub.yO.sub.x.
In one embodiment, the first metal oxide material 29 is
Zr.sub.yO.sub.x, the second dielectric material 32 is a mixture of
Ti.sub.yO.sub.x and SiO.sub.x, and the additional dielectric
material 26 is Al.sub.yO.sub.x.
[0051] In some embodiments, the first and second metal oxide
materials 29, 32 may be heated, as shown by arrows 40 in FIG. 5C.
Heating (i.e., annealing) may cause at least some crystallization
of the first metal oxide material 29, producing first dielectric
material 20. The annealing may also cause or induce the migration
or diffusion of at least some of the metal oxides of the second
metal oxide material 32 into the first metal oxide material 29. In
other words, the first metal oxide material 29 may become at least
partially doped with molecules of the second metal oxide material
32 through the annealing. The first and second metal oxide
materials 29, 32 are denoted in FIGS. 5C and 5D as first and second
dielectric materials 20, 22 to indicate that the materials have
been annealed. The interface between the first and second
dielectric materials 20, 22 may not be as distinct or clear as is
illustrated in FIG. 5C. For example, in some embodiments, the
interface may more accurately be represented by a gradient of
varying concentration of metal oxides of the second dielectric
material 22 in the first dielectric material 20. In some
embodiments, substantially all of the second dielectric material 22
may be incorporated into the first dielectric material 20 by way of
diffusion.
[0052] In some embodiments, annealing may also cause at least some
crystallization of the second metal oxide material 32. The
temperature used to anneal and crystallize a dielectric material
may depend on the composition of the dielectric material. The
amount of time to which the first and second metal oxide materials
29, 32 are exposed to heat may depend on the anneal temperature. At
a relatively high anneal temperature, the amount of time to induce
crystallization may be less than the amount of time to induce
crystallization at a relatively lower temperature. The anneal
temperature and anneal time may be chosen to tailor the level of
crystallization of at least portions of at least one of the first
and second dielectric materials 20, 22. The anneal temperature and
anneal time may also be selected to tailor the amount of dopant
diffusion between the first and second dielectric materials 20, 22.
By way of example and not limitation, the anneal temperature may be
in the range of from about 300.degree. C. to about 700.degree. C.,
such as from about 500.degree. C. to about 700.degree. C., and the
anneal time may be in the range of from about 1 minute to about 60
minutes, such as from about 3 minutes to about 5 minutes. The
anneal may be conducted by increasing the temperature in a gradient
or stepwise manner, or by raising the temperature to the desired
temperature.
[0053] Annealing may take place in any atmosphere, depending on the
desired properties of the first and second dielectric materials 20,
22 for their intended use. For example, annealing may take place in
an inert (e.g., non-reactive) atmosphere, such as N.sub.2, Ar, or
He, in an oxidizing atmosphere, or in a reducing atmosphere.
[0054] Optionally, the first metal oxide material 29 may be
annealed and at least partially crystallized before the second
metal oxide material 32 is formed thereon (not shown). After the
second metal oxide material 32 is formed, the first and second
metal oxide materials 29, 32 may be annealed again. This process
may result in an insulative element 10 including first and second
dielectric materials 20, 22 having an effective dielectric constant
that is lower than an effective dielectric constant resulting from
a process in which the anneal and crystallization of the first
metal oxide material 29 is not conducted before the foimation of
the second metal oxide material 32. Without being bound to a
particular theory, it is believed that molecules from the second
metal oxide material 32 diffuse more readily into an at least
partially amorphous first metal oxide material 29 than into an at
least partially crystallized first metal oxide material 29. The
amount of diffusion between the first and second metal oxide
materials 29, 32 may affect the overall dielectric constant of an
insulative element 10 that includes the first and second dielectric
materials 20, 22.
[0055] In some embodiments, the crystallization of at least
portions of one or more of the first metal oxide material 29 and
the second metal oxide material 32 may be induced through process
acts involving heat that occur after forming the first and second
metal oxide materials 29, 32, and not by a separate anneal act as
described with reference to FIG. 5C. Additionally, the dispersion
of molecules (also referred to as "doping") from the second metal
oxide material 32 into the first metal oxide material 29 may be
accomplished through process acts involving heat that occur after
forming the first and second metal oxide materials 29, 32, and not
by a separate anneal act as described with reference to FIG. 5C.
For example, the first and second metal oxide materials 29, 32 may
at least partially include one or more amorphous regions at
formation. After formation of the first and second metal oxide
materials 29, 32 over the substrate 24, one or more further
processing acts, such as a backend process, may occur that subject
the first and second metal oxide materials 29, 32 to heat for a
desired period of time. By way of example, later deposition,
diffusion, or anneal acts involved in forming or modifying one or
more other structures (such as, for example, an electrode, a
capping layer, contacts, or insulating layers) of the semiconductor
device structure 30 may produce sufficient heat to crystallize one
or more portions of the first and second dielectric metal oxide
materials 29, 32, thus promoting dispersion of molecules from the
second metal oxide material 32 into the first dielectric metal
oxide material 29 (i.e., doping). In such embodiments, a separate
anneal act (as described with reference to FIG. 5C) may not be
utilized to achieve the crystallization and doping that may be
desired in a specific application.
[0056] Referring now to FIG. 5D, optionally, one or more additional
materials 38 may be formed over the second dielectric material 22.
For example, in embodiments where the first and second dielectric
materials 20, 22 are used as a capacitor dielectric (e.g., as the
dielectric material 14 shown in FIG. 4), the substrate 24 may be or
include a first electrode and the one or more additional materials
38 may be or include a second electrode. The second electrode may
be formed by conventional semiconductor fabrication techniques,
which are not described in detail herein.
[0057] By way of another example, in embodiments where the first
and second dielectric materials 20, 22 are used as a gate
dielectric in a volatile transistor (not shown), the substrate 24
may be a semiconductor substrate and the one or more additional
materials 38 may be an electrically conductive gate structure. The
conductive gate structure may be formed by conventional
semiconductor fabrication techniques, which are not described in
detail herein. By way of yet another example, in embodiments where
the first and second dielectric materials 20, 22 are used as a
dielectric structure in a non-volatile transistor (not shown), the
substrate 24 may be a conductive charge retaining material and the
one or more additional materials 38 may be a conductive control
gate material. The conductive control gate material may be formed
by conventional semiconductor fabrication techniques, which are not
described in detail herein.
[0058] Another embodiment of a method of forming an insulative
element 10 (as shown in FIG. 2, for example) or a capacitor is
shown in FIGS. 6A through 6E.
[0059] A first metal oxide material 29 may be formed on a substrate
24, as shown in FIG. 6A and as described above in relation to FIG.
5A. An additional oxide material 27 may be formed over the first
metal oxide material 29, as shown in FIG. 6B. In some embodiments,
the additional oxide material 27 may be a thin layer (relative to
the thickness of the first metal oxide material 29) of material
having a different dielectric constant than the first metal oxide
material 29. For example, the additional oxide material 27 may be
formed to have a thickness in the range of about one monolayer to
about 5 .ANG. at formation.
[0060] The additional oxide material 27 may function as a diffusion
barrier to reduce, control, or eliminate diffusion or migration of
dopants across the thickness of the additional oxide material 27 in
a subsequent process involving heating of the insulative element
10. The additional oxide material 27 may be formed to include, by
way of example, one or more of HfO.sub.2, SiO.sub.2,
Al.sub.2O.sub.3, GeO.sub.2, an oxynitride, and a rare earth oxide.
For example, the additional oxide material 27 may be or include a
metal oxide material.
[0061] A second metal oxide material 32 may be formed over the
additional oxide material 27, as shown in FIG. 6C and as explained
above with reference to FIG. 5B. The second metal oxide material 32
may be selected to have a different dielectric constant than the
first metal oxide 29 and the additional oxide material 27. For
example, the second metal oxide material 32 may have a higher
dielectric constant than the first metal oxide material 29.
[0062] The first metal oxide material 29, second metal oxide
material 32, and additional oxide material 27 may be annealed to
induce one or more of crystallization and diffusion, as shown by
arrows 40 in FIG. 6D. Without being bound to a particular theory,
the presence of the additional oxide material 27 between the first
and second metal oxide materials 29, 32 may substantially reduce,
control, or eliminate diffusion (e.g., doping) of the first metal
oxide material 29 with molecules of the second metal oxide material
32 during the annealing process. However, the anneal may cause
molecules from the additional oxide material 27 to diffuse into at
least one of the first metal oxide material 29 and the second metal
oxide material 32. One or more of the first metal oxide material
29, second metal oxide material 32, and additional oxide material
27 may be at least partially crystallized by the annealing. For
example, substantially all of the first metal oxide material 29 may
be crystallized by the annealing.
[0063] Optionally, the annealing may not occur at this point in the
process. Instead, the annealing may occur during a subsequent
process act, such as by heating from a backend process. By way of
example and not limitation, any other subsequent deposition,
diffusion, or anneal acts in conjunction with forming the
semiconductor device structure 30 incorporating an insulative
element 10 formed by this method may provide sufficient heat to
crystallize at least a portion of the first metal oxide material
29. The heat from the backend process may also induce diffusion of
dopants between the additional oxide material 27 and at least one
of the first metal oxide material 29 and the second metal oxide
material 32.
[0064] The annealing or heating from a backend process may induce
crystallization and doping of one or more of the first metal oxide
material 29, second metal oxide material 32, and additional oxide
material 27, resulting in an insulative element including a first
dielectric material 20, a second dielectric material 22, and an
additional dielectric material 26, as illustrated in FIG. 6D.
[0065] Optionally, one or more additional materials 38 may be
formed over the second dielectric material 22, as shown in FIG. 6E
and as explained above with reference to FIG. 5C. For example, the
dielectric material formed by this method may function as a
capacitor dielectric, and the substrate 24 may be or include a
first electrode and the one or more additional materials 38 may be
or include a second electrode. The second electrode may be formed
by conventional semiconductor fabrication techniques, which are not
described in detail herein.
[0066] The method described with reference to FIGS. 6A through 6E
may, in some embodiments of the invention, be altered by forming
the additional dielectric material 26 at a different location. For
example, the additional dielectric material 26 may be formed before
the first metal oxide material 29 (i.e., the additional dielectric
material 26 may be located between the substrate 24 and the first
dielectric material 20) (not shown). By way of another example, the
additional dielectric material 26 may be formed after the second
metal oxide material 32 (i.e., the additional dielectric material
26 may be located between the second dielectric material 22 and the
one or more additional materials 38) (not shown). In some
embodiments, more than one additional dielectric material 26 may be
formed, and multiple locations in the dielectric structure may have
an additional dielectric material 26. Each variation in location of
the one or more additional dielectric materials 26 may change the
properties (e.g., capacitance, dielectric constant, leakage
current) of the insulative element 10 formed by the methods
described. In this manner, the properties of the dielectric
structure may be tailored to the specific application
contemplated.
[0067] Another embodiment of a method of forming an insulative
element 10 (as shown in FIG. 3, for example) or a capacitor is
shown in FIGS. 7A through 7F.
[0068] A first region 35 of a first metal oxide material 29 may be
foiined on a substrate 24, as shown in FIG. 7A and as described
above in relation to FIG. 5A. The first region 35 may be at least
substantially amorphous at formation. Next, the first region 35 may
be annealed to induce at least some crystallization of the first
region 35 of the first metal oxide material 29, as shown by the
arrows 42 representing a first anneal in FIG. 7B. This first anneal
may result in an at least partially crystallized first region 33 of
a first dielectric material 20 (see FIG. 3). In some embodiments,
at least substantially all of the first region 33 may be
crystallized through the first anneal.
[0069] After the first region 33 is annealed and at least partially
crystallized, a second region 36 of the first metal oxide material
29 may be formed over the first region 33, as shown in FIG. 7C. The
second region 36 may be at least substantially amorphous at
formation. The relative thicknesses of the first region 35 and the
second region 36 may be adjusted to tailor the dielectric constant
(k) of the insulative element 10.
[0070] A second metal oxide material 32 may be formed over the
second region 36, as shown in FIG. 7D and as explained above with
reference to FIG. 5B. The second metal oxide material 32 may be
selected to have a different dielectric constant than the first and
second regions 35, 36 of the first metal oxide material 29. For
example, the second metal oxide material 32 may be selected to have
a higher dielectric constant than the first metal oxide material
29.
[0071] The first region 33, the second region 36, and the second
metal oxide material 32 may be annealed, as shown by arrows 44
representing a second anneal, to induce one or more of
crystallization and diffusion, as shown in FIG. 7E. Without being
bound to a particular theory, the initial crystallization or
pre-crystallization of the first region 35 of the first metal oxide
material 29 (forming an at least partially crystallized first
region 33) may reduce, control, or eliminate doping of the first
region 33 with molecules from the second metal oxide material 32
during the annealing process, while the amorphous state of the
second region 36 of the first metal oxide material 29 may enable at
least some doping of the second region 36 with molecules of the
second metal oxide material 32 during the annealing process. By way
of example and not limitation, this method may result in a first
region 33 of a first dielectric material 20 being at least
substantially free of dopants from the second metal oxide material
32 and a second region 34 of a first dielectric material 20
including dopants from the second metal oxide material 32 dispersed
therein (see FIGS. 7E and 7F).
[0072] Optionally, one or more additional materials 38 may be
formed over the second dielectric material 22, as shown in FIG. 7F
and as explained above with reference to FIG. 5C. In embodiments
where this method is used to form a capacitor, the substrate 24 may
be or include a first electrode and the one or more additional
materials 38 may be or include a second electrode. The second
electrode may be formed by conventional semiconductor fabrication
techniques, which are not described in detail herein.
[0073] The method described with reference to FIGS. 7A through 7F
may, in some embodiments of the invention, be altered by omitting
the second anneal represented by arrows 44 in FIG. 7E and replacing
it with heat produced by a backend process. For example, any other
subsequent deposition, diffusion, or anneal in conjunction with
forming an integrated circuit incorporating an insulative element
10 formed by this method may provide sufficient heat to crystallize
at least a portion of the second region 36 and to induce diffusion
of at least some dopants from the second metal oxide material 32
into the second region 36, forming an at least partially
crystallized and doped second region 34 of the first dielectric
material 20. In this manner, the heat sufficient to crystallize at
least a portion of the second region 34 and to induce diffusion of
at least some dopants from the second metal oxide material 32 into
the second region 34 may be provided by a backend process rather
than by a separate anneal act (as shown in FIG. 7E).
CONCLUSION
[0074] In one embodiment, a method of forming an insulative element
is described including forming a first metal oxide material on a
substrate, forming a second metal oxide material over at least a
portion of the first metal oxide material, and heating at least one
of the first metal oxide material and the second metal oxide
material to crystallize at least a portion thereof.
[0075] In a further embodiment, a method of forming an insulative
element is described, including forming a substantially crystalline
dielectric material on a substrate, forming a metal oxide material
having a greater dielectric constant than the substantially
crystalline dielectric material over the substantially crystalline
dielectric material, and heating the substantially crystalline
dielectric material and the metal oxide material to induce
diffusion of dopants from the metal oxide material into the
substantially crystalline dielectric material.
[0076] In an additional embodiment, a method of forming a capacitor
is described, including forming a first electrode, forming a
dielectric material over and in contact with the first electrode
including forming a first oxide and a second oxide, heating at
least one of the first and second oxides, and forming a second
electrode over the dielectric material. The heating of the at least
one of the first and second oxides at least partially crystallizes
at least one of the first and second oxides.
[0077] In another embodiment, an insulative element is described,
including a substantially crystalline first dielectric material
having a first dielectric constant on a substrate and a second
dielectric material having a second dielectric constant different
than the first dielectric constant positioned over the first
dielectric material. The first dielectric material may include
dopants of the second dielectric material dispersed therein. The
dielectric structure may also include an additional dielectric
material.
[0078] In an additional embodiment, an insulative element is
described, including a substrate and a first dielectric material in
contact with at least a portion of the substrate. The first
dielectric material may include an at least substantially
crystalline metal oxide matrix and a metal oxide dopant dispersed
within at least a portion thereof. The metal oxide matrix may
include a first region including the metal oxide dopant dispersed
therein and a second region being substantially free of the metal
oxide dopant.
[0079] While the invention is susceptible to various modifications
and alternative forms, specific embodiments have been shown by way
of example in the drawings and have been described in detail
herein. However, the invention is not intended to be limited to the
particular forms disclosed. Rather, the invention is to cover all
modifications, combinations, equivalents, and alternatives falling
within the scope of the invention as defined by the following
appended claims and their legal equivalents.
* * * * *