U.S. patent application number 17/036469 was filed with the patent office on 2021-04-01 for thin film structure and electronic device including the same.
This patent application is currently assigned to Samsung Electronics Co., Ltd.. The applicant listed for this patent is Samsung Electronics Co., Ltd.. Invention is credited to Jinseong HEO, Sanghyun JO, Sangwook KIM, Hyangsook LEE, Yunseong LEE.
Application Number | 20210098596 17/036469 |
Document ID | / |
Family ID | 1000005161754 |
Filed Date | 2021-04-01 |
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United States Patent
Application |
20210098596 |
Kind Code |
A1 |
JO; Sanghyun ; et
al. |
April 1, 2021 |
THIN FILM STRUCTURE AND ELECTRONIC DEVICE INCLUDING THE SAME
Abstract
Disclosed herein is a thin film structure, including a first
conductive layer on a dielectric layer including a plurality of
layers. Each of the plurality of layers includes a dopant layer
containing a dopant A and a HfO.sub.2 layer to form a compound of
Hf.sub.xA.sub.1-xO.sub.z (0<x<1, z is a real number). An
uppermost layer of the plurality of layers is thickest among the
plurality of layers. The first conductive layer contacts the
uppermost layer.
Inventors: |
JO; Sanghyun; (Seoul,
KR) ; HEO; Jinseong; (Seoul, KR) ; LEE;
Hyangsook; (Suwon-si, KR) ; KIM; Sangwook;
(Seongnam-si, KR) ; LEE; Yunseong; (Osan-si,
KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Samsung Electronics Co., Ltd. |
Suwon-si |
|
KR |
|
|
Assignee: |
Samsung Electronics Co.,
Ltd.
Suwon-si
KR
|
Family ID: |
1000005161754 |
Appl. No.: |
17/036469 |
Filed: |
September 29, 2020 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01L 29/513 20130101;
H01L 21/02356 20130101; H01L 21/022 20130101; H01L 29/517 20130101;
H01L 21/02194 20130101; H01L 21/02181 20130101; H01L 29/516
20130101; H01L 28/40 20130101 |
International
Class: |
H01L 29/51 20060101
H01L029/51; H01L 21/02 20060101 H01L021/02; H01L 49/02 20060101
H01L049/02 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 30, 2019 |
KR |
10-2019-0120539 |
Claims
1. A thin film structure, comprising: a dielectric layer including
a plurality of layers, each of the plurality of layers including a
dopant layer containing a dopant A and a HfO.sub.2 layer to form a
compound of Hf.sub.xA.sub.1-xO.sub.z (0<x<1, z is a real
number), an uppermost layer of the plurality of layers being
thickest among the plurality of layers; and a first conductive
layer on the dielectric layer, the first conductive layer
contacting the uppermost layer of the plurality of layers in the
dielectric layer.
2. The thin film structure of claim 1, wherein the uppermost layer
has a thickness of 0.25 nm or more.
3. The thin film structure of claim 1, wherein the dielectric layer
includes a first layer among the plurality of layers, the first
layer has a thickness of i*t, where i is an integer and t is a real
number, the first layers includes HfO.sub.2, and the uppermost
layer contains the dopant A and has a thickness of j*t, where j is
an integer of 3 or more and j.gtoreq.i.
4. The thin film structure of claim 3, wherein the dielectric layer
further includes a second layer and a third layer among the
plurality of layers, the second layer is on the first layer, the
second layer has a thickness of j*t and contains the dopant A, the
third layer is on the second layer, the third layer has a thickness
of i*t and includes HfO.sub.2, and j>i is satisfied.
5. The thin film structure of claim 4, wherein pairs of the second
layer and the third layer repeatedly stacked on each other several
times in the dielectric layer between the first layer and the
uppermost layer.
6. The thin film structure of claim 3, wherein the dielectric layer
further includes a second layer and a third layer among the
plurality of layers, the second layer is on the first layer, the
second layer has a thickness of m*t (i<m<j, m is an integer)
and contains a dopant A, the third layer is on the second layer,
the third layer has a thickness of n*t (i<n<j, n is an
integer), the third layer includes HfO.sub.2, and j>i is
satisfied.
7. The thin film structure of claim 6, wherein, in the dielectric
layer, pairs of the first layer and the second layer are repeatedly
disposed under the third layer.
8. The thin film structure of claim 3, wherein, the dielectric
layer further includes a second layer and a third layer among the
plurality of layers, the second layer is on the first layer, the
second layer has a thickness of i*t, the second layer contains a
dopant A, the third layer is on the second layer, the third layer
has a thickness of j*t, and the third layer includes HfO.sub.2.
9. The thin film structure of claim 8, wherein pairs of the first
layer and the second layer are repeatedly disposed in the
dielectric layer under the third layer.
10. The thin film structure of claim 3, wherein the dielectric
layer further includes a second layer and a third layer among the
plurality of layers, the second layer is on the first layer, the
second layer has a thickness of k*t (k<i, k is an integer), the
second layer contains a dopant A, the third layer is on the second
layer, the third layer has a thickness of k*t, the third layer
includes HfO.sub.2, and i=j is satisfied.
11. The thin film structure of claim 10, wherein pairs of the
second layer and the third layer are repeatedly disposed in the
dielectric layer between the first layer and the uppermost
layer.
12. The thin film structure of claim 1, wherein the dielectric
layer includes a first layer among the plurality of layers, the
first layer contains a dopant A, the first layer has a thickness of
i*t (i is an integer, and t is a real number), the first layer
includes HfO.sub.2, the uppermost layer has a thickness of j*t
(j>i, j is an integer of 3 or more), and the uppermost layer
includes HfO.sub.2.
13. The thin film structure of claim 12, wherein the dielectric
layer further includes a second layer and a third layer among the
plurality of layers, the second layer is on the first layer, the
second layer has a thickness of j*t, the second layer includes
HfO.sub.2, the third layer is on the second layer, the third layer
has a thickness of i*t, and the third layer contains a dopant
A.
14. The thin film structure of claim 13, wherein pairs of the
second layer and the third layer are repeatedly disposed between
the first layer and the uppermost layer.
15. The thin film structure of claim 1, wherein the dielectric
layer includes a first layer and second layer among the plurality
of layers, the first layer having a thickness of i*t (i is an
integer, and t is a real number), the first layer includes
HfO.sub.2, the second layer is on the first layer, the second layer
contains a dopant A, the second layer has a thickness of j*t
(j>i), the uppermost layer has a thickness of k*t (k>i, j),
and the uppermost layer includes HfO.sub.2.
16. The thin film structure of claim 1, wherein the dielectric
layer includes a first layer and a second layer among the plurality
of layers, the first layer contains a dopant A, the first layer has
a thickness of j*t (j is an integer, and t is a real number), the
second layer has a thickness of i*t (l>j), the second layer
includes HfO.sub.2, the uppermost layer has a thickness of n*t
(n>i, j), and the uppermost layer includes a dopant A.
17. The thin film structure of claim 1, wherein t is 0.05 nm or
more.
18. The thin film structure of claim 1, wherein the dielectric
layer has a thickness of about 0.5 nm to about 20 nm.
19. The thin film structure of claim 1, wherein A includes any one
of Zr, La, Y, Si, Al, and Sn.
20. The thin film structure of claim 1, wherein the first
conductive layer includes any one of a metal, a conductive oxide,
and graphene.
21. The thin film structure of claim 17, wherein t is about 0.1 nm
to about 0.9 nm.
22. The thin film structure of claim 1, wherein the uppermost layer
is HfO.sub.2.
23. The thin film structure of claim 1, wherein the uppermost layer
is ZrO.sub.2.
24. The thin film structure of claim 1, wherein z is 2, x is a
range of 0.2 to 0.8.
25. The thin film structure of claim 1, wherein a material of a
lowermost layer among the plurality of layers is different than a
material of the uppermost layer.
26. An electronic device, comprising: a semiconductor layer; and
the thin film structure of claim 1 on the semiconductor layer.
27. The electronic device of claim 26, further comprising: an
insulating layer between the semiconductor layer and the thin film
structure.
28. The electronic device of claim 27, further comprising: a second
conductive layer between the insulating layer and the thin film
structure.
29. An electronic device, comprising: a second conductive layer;
and the thin film structure of claim 1 on the second conductive
layer.
30. The electronic device of claim 29, further comprising: an
insulating layer between the second conductive layer and the thin
film structure.
31. A method of manufacturing a thin film structure, comprising:
providing a substrate; forming a dielectric layer including a
compound of Hf.sub.aA.sub.bO.sub.z (where a, b, z are real numbers)
on the substrate, the dielectric layer including a plurality of
layers, each of the plurality of layers including a dopant layer
containing a dopant A and a HfO.sub.2 layer, an uppermost layer of
the plurality of layers being thickest among the plurality of
layers; and forming a conductive layer on the dielectric layer, the
conductive layer contacting the uppermost layer.
32. The method of claim 31, further comprising: setting a kind and
the thickness of the uppermost layer depending on a content ratio
of Hf and A in the dielectric layer.
33. The method of claim 31, wherein, a content ratio of the Hf and
A in the dielectric layer is a:b, the forming the dielectric layer
includes forming the uppermost layer is as an A-dopant layer in
response to a case of a.ltoreq.b, and the forming dielectric layer
includes forming the uppermost layer as a HfO.sub.2 layer in
response to a case of a>b.
34. The method of claim 31, further comprising: performing a heat
treatment, wherein the heat treatment is performed before the
forming the conductive layer and after the forming the dielectric
layer, or the heat treatment is performed after forming the
conductive layer.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of Korean Patent
Application No. 10-2019-0120539, filed on Sep. 30, 2019, in the
Korean Intellectual Property Office, the disclosure of which is
incorporated herein in its entirety by reference.
BACKGROUND
1. Field
[0002] The present disclosure relates to a thin film structure
and/or an electronic device including the same.
2. Description of Related Art
[0003] With the down-scaling of integrated circuit devices, a space
occupied by electronic devices such as transistors and capacitors
included therein has been rapidly reduced. There may be a need for
a material that can overcome these spatial limitations and exhibit
good operation characteristics.
[0004] HfO.sub.2 is a core material used for high-k dielectric
materials in electronic devices. In order to increase the
dielectric constant and stability of this material, various studies
on doping materials and methods are being actively conducted.
Recently, it has been reported that an HfO.sub.2 thin film doped
with Zr, Si, Al, La, Y, etc. may exhibit ferroelectricity when it
has a desired (and/or alternatively predetermined) thickness or
less. Ferroelectricity has a negative capacitance effect, which can
drastically reduce the power consumption of an electronic device
employing a ferroelectric material.
[0005] Accordingly, researches on low power logic devices,
nonvolatile memories, capacitors, or the like, using a
HfO.sub.2-based dielectric material, have been actively
conducted.
SUMMARY
[0006] Provided are doped HfO.sub.2 thin films, manufacturing
methods thereof, and electronic devices using the same.
[0007] Additional aspects will be set forth in part in the
description which follows and, in part, will be apparent from the
description, or may be learned by practice of the presented
embodiments of the disclosure.
[0008] According to an embodiment, a thin film structure includes:
a dielectric layer including a plurality of layers and a first
conductive layer on the dielectric layer. Each of the plurality of
layers includes a dopant layer containing a dopant A and a
HfO.sub.2 layer to form a compound of Hf.sub.xA.sub.1-xO.sub.z
(0<x<1, z is a real number), wherein an uppermost layer of
the plurality of layers is thickest among the plurality of layers.
The first conductive layer contacts the uppermost layer of the
plurality of layers.
[0009] In some embodiments, the uppermost layer may have a
thickness of 0.25 nm or more.
[0010] In some embodiments, the dielectric layer may include a
first layer among the plurality of layers. The first layer may have
a thickness of i*t (i is an integer, and t is a real number) and
include HfO.sub.2. The uppermost layer may contain the dopant A and
have a thickness of j*t (j.gtoreq.i, j is an integer of 3 or
more).
[0011] In some embodiments, the dielectric layer may further
include a second layer and a third layer among the plurality of
layers. The second layer may be on the first layer, have a
thickness of j*t, and contain a dopant A. The third layer may be on
the second layer, have a thickness of i*t, and include HfO.sub.2,
wherein j>i is satisfied. Pairs of the second layer and the
third layer may be repeatedly disposed between the first layer and
the uppermost layer.
[0012] In some embodiments, the dielectric layer may further
include a second layer and a third layer among the plurality of
layers. The second layer may be on the first layer, have a
thickness of m*t (i<m<j, m is an integer), and contain a
dopant A. The third layer may be on the second layer, have a
thickness of n*t (i<n<j, n is an integer), and include
HfO.sub.2, wherein j>i is satisfied. Pairs of the first layer
and the second layer may be repeatedly disposed under the third
layer.
[0013] In some embodiments, the dielectric layer may further
include a second layer and a third layer among the plurality of
layers. The second layer may be on the first layer, having a
thickness of i*t, and contain a dopant A. The third layer may be on
the second layer, have a thickness of j*t, and include HfO.sub.2.
Pairs of the first layer and the second layer may be repeatedly
disposed under the third layer.
[0014] In some embodiments, the dielectric layer may further
include a second layer and a third layer among the plurality of
layers. The second layer may be on the first layer, have a
thickness of k*t (k<i, k is an integer, wherein i=j is
satisfied), and contain a dopant A. The third layer may be on the
second layer, have a thickness of k*t, and include HfO.sub.2. Pairs
of the second layer and the third layer may be repeatedly disposed
between the first layer and the uppermost layer.
[0015] In some embodiments, the dielectric layer may include a
first layer among the plurality of layers. The first layer may
contain a dopant A, have a thickness of i*t (i is an integer, and t
is a real number), and include HfO.sub.2. The uppermost layer may
have a thickness of j*t (j>i, j is an integer of 3 or more) and
include HfO.sub.2.
[0016] In some embodiments, the dielectric layer may further
include a second layer and a third layer among the plurality of
layers. The second layer may be on the first layer, have a
thickness of j*t, and include HfO.sub.2. The third layer may be on
the second layer, have a thickness of i*t, and contain a dopant A.
Pairs of the second layer and the third layer may be repeatedly
disposed between the first layer and the uppermost layer.
[0017] In some embodiments, the dielectric layer may include a
first layer and a second layer among the plurality of layers. The
first layer may have a thickness of i*t (i is an integer, and t is
a real number) and include HfO.sub.2. The second layer may be on
the first layer, contain a dopant A, and have a thickness of j*t
(j>i). The uppermost layer have a thickness of k*t (k>i, j)
and including HfO.sub.2.
[0018] In some embodiments, the dielectric layer may further
include a first layer and a second layer among the plurality of
layers. The first layer may contain a dopant A and have a thickness
of j*t (j is an integer, and t is a real number). The second layer
may have a thickness of i*t (i>j) and include HfO.sub.2. The
uppermost layer may have a thickness of n*t (n>i, j) and include
a dopant A.
[0019] In some embodiments, t may be 0.05 nm or more.
[0020] In some embodiment, t may be about 0.1 nm to about 0.9
nm.
[0021] In some embodiments, the dielectric layer may have a
thickness of about 0.5 nm to about 20 nm.
[0022] In some embodiments, A may include any one of Zr, La, Y, Si,
Al, and Sn.
[0023] In some embodiments, the first conductive layer may include
any one of a metal, a conductive oxide, and graphene.
[0024] In some embodiments, the uppermost layer may be
HfO.sub.2.
[0025] In some embodiments, the uppermost layer may be
ZrO.sub.2.
[0026] In some embodiments, in the compound of
Hf.sub.xA.sub.1-xO.sub.z, z may be 2, and x may be in a range of
0.2 to 0.8.
[0027] In some embodiments, a material of a lowermost layer among
the plurality of layers may be different than a material of the
uppermost layer.
[0028] According to an embodiment, a method of manufacturing a thin
film structure includes providing a substrate; forming a dielectric
layer including a compound of Hf.sub.aA.sub.bO.sub.z (where a, b, z
are real numbers) on the substrate, the dielectric layer including
a plurality of layers, each of the plurality of layers including a
dopant layer containing a dopant A and a HfO.sub.2 layer, and an
uppermost layer of the plurality of layers being thickest among the
plurality of layers; and forming a conductive layer on the
dielectric layer, the conductive layer contacting the uppermost
layer.
[0029] In some embodiments, the method may further include setting
a kind and the thickness of the uppermost layer depending on a
content ratio of Hf and A in the dielectric layer.
[0030] In some embodiments, the content ratio in the dielectric
layer may be a:b. The forming the dielectric layer may include
forming the uppermost layer as an A-dopant layer in response to a
case of a.ltoreq.b, and the forming the dielectric layer may
include forming the uppermost layer as a HfO.sub.2 layer in
response to a case of a>b.
[0031] In some embodiments, the method may further include:
performing heat treatment. The heat treatment may be performed
before the forming the conductive layer and after the forming the
dielectric layer. Alternatively, the heat treatment may be
performed after the forming the conductive layer.
[0032] According to another embodiment, an electronic device
includes a semiconductor layer; and any one of the aforementioned
thin film structures on the semiconductor layer.
[0033] In some embodiments, the electronic device may further
include an insulating layer between the semiconductor layer and the
thin film structure.
[0034] In some embodiments, the electronic device may further
include a second conductive layer between the insulating layer and
the thin film structure.
[0035] According to another embodiment, an electronic device
includes a second conductive layer and any one of the
aforementioned thin film structures on the semiconductor layer.
[0036] In some embodiments, the electronic device may further
include an insulating layer between the second conductive layer and
the thin film structure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0037] The above and other aspects, features, and effects of
certain embodiments of the disclosure will be more apparent from
the following description taken in conjunction with the
accompanying drawings, in which:
[0038] FIG. 1 is a schematic cross-sectional view of a thin film
structure according to an embodiment;
[0039] FIG. 2 is a cross-sectional view conceptually illustrating
the structure of a dielectric layer employed in a thin film
structure according to an embodiment;
[0040] FIG. 3A is a cross-sectional view illustrating an example
structure of a dielectric layer employed in a thin film structure
according to an embodiment;
[0041] FIG. 3B is an electron microscope photograph of the
dielectric layer of FIG. 3A;
[0042] FIG. 4 is a cross-sectional view illustrating an example
structure of a comparative dielectric layer to be compared with the
dielectric layer of FIG. 3A;
[0043] FIG. 5 is a graph comparing a dielectric constant of the
dielectric layer of FIG. 3A with a dielectric constant of the
comparative dielectric layer of FIG. 4;
[0044] FIG. 6 is a cross-sectional view illustrating another
example structure of a dielectric layer employed in a thin film
structure according to another embodiment;
[0045] FIG. 7 is a cross-sectional view illustrating another
example structure of a dielectric layer employed in a thin film
structure according to still another embodiment;
[0046] FIG. 8A is a cross-sectional view illustrating another
example structure of a dielectric layer employed in a thin film
structure according to still another embodiment;
[0047] FIG. 8B is an electron microscope photograph of the
dielectric layer of FIG. 8A;
[0048] FIG. 9A is a cross-sectional view illustrating another
example structure of a dielectric layer employed in a thin film
structure according to still another embodiment;
[0049] FIG. 9B is an electron microscope photograph of the
dielectric layer of FIG. 9A;
[0050] FIG. 10A is a cross-sectional view illustrating another
example structure of a dielectric layer employed in a thin film
structure according to still another embodiment;
[0051] FIG. 10B is an electron microscope photograph of the
dielectric layer of FIG. 9A;
[0052] FIG. 11 is a cross-sectional view illustrating another
example structure of a dielectric layer employed in a thin film
structure according to still another embodiment;
[0053] FIG. 12A is a cross-sectional view illustrating another
example structure of a dielectric layer employed in a thin film
structure according to still another embodiment;
[0054] FIG. 12B is an electron microscope photograph of the
dielectric layer of FIG. 12A;
[0055] FIG. 13 is a cross-sectional view illustrating a structure
of a comparative dielectric layer to be compared with the
dielectric layer of FIG. 12A;
[0056] FIG. 14 is a graph comparing a dielectric constant of the
dielectric layer of FIG. 12A with a dielectric constant of the
comparative dielectric layer of FIG. 11;
[0057] FIG. 15 is a cross-sectional view illustrating another
example structure of a dielectric layer employed in a thin film
structure according to still another embodiment;
[0058] FIG. 16 is a flowchart schematically illustrating operations
of a method of manufacturing a thin film structure according to an
embodiment;
[0059] FIG. 17 is a cross-sectional view illustrating the schematic
structure of an electronic device according to an embodiment;
[0060] FIG. 18 is a cross-sectional view illustrating the schematic
structure of an electronic device according to another
embodiment;
[0061] FIG. 19 is a cross-sectional view illustrating the schematic
structure of an electronic device according to still another
embodiment;
[0062] FIG. 20 is a cross-sectional view illustrating the schematic
structure of an electronic device according to still another
embodiment;
[0063] FIG. 21 is a cross-sectional view illustrating the schematic
structure of an electronic device according to still another
embodiment; and
[0064] FIG. 22 is a cross-sectional view illustrating the schematic
structure of an electronic device according to still another
embodiment.
DETAILED DESCRIPTION
[0065] Reference will now be made in detail to embodiments,
examples of which are illustrated in the accompanying drawings,
wherein like reference numerals refer to like elements throughout.
In this regard, the present embodiments may have different forms
and should not be construed as being limited to the descriptions
set forth herein. Accordingly, the embodiments are merely described
below, by referring to the figures, to explain aspects. As used
herein, the term "and/or" includes any and all combinations of one
or more of the associated listed items. Expressions such as "at
least one of," when preceding a list of elements, modify the entire
list of elements and do not modify the individual elements of the
list.
[0066] Hereinafter, embodiments of the present disclosure will be
described in detail with reference to the accompanying drawings.
Embodiments are merely example, and various modifications are
possible from these embodiments. In the following drawings, like
numbers refer to like elements, and the size of each element may be
exaggerated for clarity and convenience of description. When the
terms "about" or "substantially" are used in this specification in
connection with a numerical value, it is intended that the
associated numerical value includes a manufacturing or operational
tolerance (e.g., .+-.10%) around the stated numerical value.
Moreover, when the words "generally" and "substantially" are used
in connection with geometric shapes, it is intended that precision
of the geometric shape is not required but that latitude for the
shape is within the scope of the disclosure. Further, regardless of
whether numerical values or shapes are modified as "about" or
"substantially," it will be understood that these values and shapes
should be construed as including a manufacturing or operational
tolerance (e.g., .+-.10%) around the stated numerical values or
shapes.
[0067] Hereinafter, when a part of a layer, film, region, plate,
etc. is said to be "on" or "over" another part, it includes not
only being directly on another part but also having another part
therebetween.
[0068] Although the terms "first," "second," etc. may be used
herein to describe various elements, these elements should not be
limited by these terms. These terms are only used to distinguish
one element from another element.
[0069] The singular forms "a," "an" and "the" are intended to
include the plural forms as well, unless the context clearly
indicates otherwise. When a part is said to "include" a component,
this means that, unless specifically stated otherwise, it may
further include other components rather than excluding other
components.
[0070] The terms " . . . unit" and "module" described in the
specification mean a unit that processes at least one function or
operation, and may be implemented in hardware or software, or a
combination of hardware and software.
[0071] The use of the term "above-described or aforementioned" and
similar indicating terminology may correspond to both the singular
form and the plural form.
[0072] The operations constituting the method may be performed in a
suitable order, unless there is an explicit statement that they
should be done in the order described. The use of all example terms
(e.g., etc.) is merely for the purpose of describing the technical
spirit in detail and is not intended to limit the scope of the
rights as such terms are not limited by the claims.
[0073] FIG. 1 is a schematic cross-sectional view of a thin film
structure according to an embodiment, and FIG. 2 is a
cross-sectional view conceptually illustrating the structure of a
dielectric layer employed in a thin film structure according to an
embodiment.
[0074] A thin film structure 1000 includes a dielectric layer 500
and a first conductive layer 700 disposed on the dielectric layer
500.
[0075] The dielectric layer 500 includes a compound of
Hf.sub.xA.sub.1-xO.sub.z. Such a compound may be implemented by a
multi-layer structure including a dopant layer having a dopant A
and a HfO.sub.2 layer.
[0076] The dopant A may include any one of transition metals such
as Zr, La, and Y, Si, Al, and Sn, and may be a binary compound, a
ternary compound or more. The dopant layer may include any one of
transition metal-based oxide such as ZrO.sub.2, LaO.sub.2, or
YO.sub.2, and SiO.sub.2, Al.sub.2O.sub.3, and SnO.sub.2.
[0077] The first conductive layer 700 may include any one of a
metal such as TiN, W, Mo, or Ni; a conductive oxide such as
RuO.sub.2, SrRuO.sub.3, or ITO; and a 2D material such as
graphene.
[0078] The layer number, thickness, and repetitive form of the
plurality of layers constituting the dielectric layer 500 may be
set in consideration of the composition ratio of
Hf.sub.xA.sub.1-xO.sub.z (0<x<1, z is a real number), that
is, the content ratio of Hf and A, and the thickness of the
dielectric layer 500. The configuration of the plurality of layers
may be determined to achieve a higher dielectric constant for the
given content ratio of Hf and A.
[0079] In the thin film structure 1000 according to an embodiment,
the thickness and composition of the uppermost layer UP of the
dielectric layer 500, the uppermost layer contacting the first
conductive layer 700, are appropriately set in order to implement
the dielectric layer 500 having good crystallinity and a high
dielectric constant.
[0080] In the plurality of layers constituting the dielectric layer
500, the thickness TH of the uppermost layer UP of the dielectric
layer 500 may be thickest. The thickness of at least one of the
plurality of layers may be equal to the thickness TH of the
uppermost layer UP. In other words, the thickness of each of the
plurality of layers is equal to or thinner than the thickness TH of
the uppermost layer UP. The uppermost layer UP may be a HfO.sub.2
layer, or may be an A-dopant layer including dopant A. Whether the
uppermost layer UP is a HfO.sub.2 layer or an A-dopant layer may be
determined in consideration of the content ratio of Hf and A in the
compound Hf.sub.xA.sub.1-x O.sub.z constituting the dielectric
layer 500.
[0081] The thickness of the uppermost layer UP may be determined in
consideration of the fact that the electrical properties of the
dielectric layer 500 may vary depending on the thickness of the
uppermost layer UP even when the composition of the dielectric
layer 500 is the same. The thickness of the uppermost layer UP may
be about 0.25 nm or more (e.g., about 0.25 nm to about 1 nm, 2 nm,
5 nm, or 10 nm).
[0082] The thickness of the dielectric layer 500 is a factor that
affects other electrical properties such as dielectric constant of
the dielectric layer 500, and may be set according to desired
performance. The total thickness of the dielectric layer 500 may be
about 0.5 nm to about 20 nm. However, the thickness of the
uppermost layer UP and the thickness of the dielectric layer 500
are not limited thereto.
[0083] The dielectric layer 500 may be formed on a desired (and/or
alternatively predetermined) substrate SU. The kind of the
substrate SU is not particularly limited, and may be, for example,
determined according to the structure of an electronic device in
which the dielectric layer 500 is to be utilized.
[0084] Hereinafter, various embodiments of dielectric layers will
be described. Embodiments include various structures that exhibit
an improved dielectric constant. Such embodiments are deduced in
consideration of the fact that, even when the composition of a
dielectric layer is the same, the crystallinity of the dielectric
layer is changed depending on the thickness or kind of an uppermost
layer, and thus the dielectric constant thereof is also
changed.
[0085] The following embodiments illustrate that the dielectric
layer of FIG. 2 is variously implemented depending on the content
ratio of Hf and A, but the implementation form of the dielectric
layer 500 is not limited to example explanations to be described
later. That is, as long as the requirements of the thickness and
type of the uppermost layer UP are satisfied, the position, number
and thickness of an HfO.sub.2 layer and an A-dopant layer disposed
under the uppermost layer UP may be variously changed.
[0086] Hereinafter, it will be described that the dopant A is a Zr
and the A-dopant layer is ZrO.sub.2 layer, but the present
disclosure is not limited thereto, and the aforementioned various
dopant materials may be employed in the dielectric layer.
[0087] FIG. 3A is a cross-sectional view illustrating an example
structure of a dielectric layer employed in a thin film structure
according to an embodiment. FIG. 3B is an electron microscope
photograph of the dielectric layer of FIG. 3A.
[0088] A dielectric layer 501 includes a first layer 11 including
HfO.sub.2 prepared in i-cycles, and an uppermost layer UP1
including ZrO.sub.2 prepared in j-cycles (j>i).
[0089] In order to form the dielectric layer 501, deposition
methods, such as atomic layer deposition (ALD), metal organic
atomic layer deposition (MOALD), chemical vapor deposition (CVD),
metal organic chemical vapor deposition (MOCVD), and physical vapor
deposition (PVD) may be used. Each of the above methods includes
processes of placing a target substrate in a chamber, heating the
chamber to a desired (and/or alternatively predetermined)
temperature, and supplying a source material. Through these
processes, the source material is deposited on the target
substrate. Here, the cycle is a deposition unit that is determined
at desired (and/or alternatively predetermined) process conditions
including temperature and time. When the thickness formed in one
cycle is t, the thickness of the first layer 11 is i*t, and the
thickness of the uppermost layer UP1 is j*t. The thickness formed
in one cycle is expressed by t, and t may be 0.05 nm or more. For
example, t may be about 0.1 nm to about 0.9 nm, but is not limited
thereto. Hereinafter, the expression 1-cycles' may be used
interchangeably with the expression `thickness i*t`.
[0090] The dielectric layer 501 may further include a second layer
12 disposed on the first layer 11, having a thickness of j*t and
including ZrO.sub.2, and a third layer 13 disposed on the second
layer 12, having a thickness of i*t and including HfO.sub.2. Pairs
of the second layer 12 and the third layer 13 may be repeatedly
disposed between the first layer 11 and the uppermost layer UP1
several times. The number of repeated times may be determined in
consideration of the overall thickness of the dielectric layer 501
to be formed.
[0091] When the content ratio of Hf and Zr in the dielectric layer
501 is a:b, a<b is satisfied, that is, i<j is satisfied. For
example, j may be 3 or more (e.g., in a range of 3 to 10). A layer
including ZrO.sub.2 is formed to be thicker than a layer including
HfO.sub.2. The uppermost layer UP1 includes ZrO.sub.2.
[0092] FIG. 3B is an electron microscope photograph of the
dielectric layer 501 of FIG. 3A, and illustrates a case where i=1
and j=4 are satisfied, and pairs of HfO.sub.2 1-cycle and ZrO.sub.2
4-cycles are repeated five times.
[0093] The thin film shown in FIG. 3B is formed in the order of Si
layer/SiO.sub.2 layer/dielectric layer 502/metal layer M. The
dielectric layer 502 forms Hf.sub.0.2Zr.sub.0.8O.sub.2. The
dielectric layer 501 exhibits good crystallinity as shown in the
drawing.
[0094] FIG. 4 is a cross-sectional view illustrating an example
structure of a comparative dielectric layer to be compared with the
dielectric layer of FIG. 3A.
[0095] The dielectric layer 50 forms Hf.sub.0.2Zr.sub.0.8O.sub.2 of
the same composition as the dielectric layer 501 of FIG. 3A, but is
different from the dielectric layer 501 in that first layers 1 of
ZrO.sub.2 4-cycles and second layers 2 of HfO.sub.2 1-cycle are
repeatedly disposed in this order.
[0096] FIG. 5 is a graph comparing a dielectric constant of the
dielectric layer of FIG. 3A with a dielectric constant of the
comparative dielectric layer of FIG. 4.
[0097] The dielectric layer 501 according to example embodiments
exhibits a higher dielectric constant than the comparative
dielectric layer 50. The reason for this is that crystallinity is
changed depending on the shape (type, thickness) of the uppermost
layer contacting the conductive layer even in the cases of the same
composition. That is, in the case where the uppermost layer is a
HfO.sub.2 layer having a thickness of 1*t, lower crystallinity is
exhibited as compared with the case where the uppermost layer is a
ZrO.sub.2 layer having a thickness of 4*t.
[0098] FIG. 6 is a cross-sectional view illustrating another
example structure of a dielectric layer employed in a thin film
structure according to another embodiment.
[0099] A dielectric layer 502 includes a first layer 21 including
HfO.sub.2 prepared in i-cycles, and an uppermost layer UP2
including ZrO.sub.2 prepared in j-cycles (j>i). That is, the
first layer 21 is an HfO.sub.2 layer having a thickness of i*t, and
the uppermost layer UP2 is a ZrO.sub.2 layer having a thickness of
j*t. j may be 3 or more.
[0100] The dielectric layer 502 may further include a second layer
22 disposed on the first layer 21, prepared in m-cycles, having a
thickness of m*t (i<m<j) and including dopant A, and a third
layer 23 disposed on the second layer 22, prepared in n-cycles,
having a thickness of n*t (i<n<j) and including HfO.sub.2.
Pairs of the first layer 21 and the second layer 22 may be
repeatedly disposed under the third layer 23.
[0101] When the content ratio of Hf and Zr in the dielectric layer
502 of the present embodiment, similarly to the aforementioned
dielectric layer 501, is a:b, a<b is satisfied. In the
dielectric layer 502 of the present embodiment, the thicknesses of
the first layer 21 and the second layer 22 adjacent to each other
are set depending on the above content condition, but the
thicknesses of the uppermost layer UP2 and the third layer 23
closet thereto may be set to be thicker than the thicknesses of the
second layer 22 and the first layer 11, respectively. For example,
j may be 3 or more, and i:m=n:j may be satisfied. However, the
present disclosure is not limited thereto.
[0102] Although it is illustrated in the embodiments of FIGS. 3A
and 5 that the uppermost layer is set as a ZrO.sub.2 layer when the
content of Hf in each of the dielectric layer 501 and 502 is lower
than the content of Zr in each of the dielectric layer 501 and 502,
in another embodiment, even in this case, the uppermost layer may
be set as a HfO.sub.2 layer, and may be set to be thickest.
[0103] FIG. 7 is a cross-sectional view illustrating another
example structure of a dielectric layer employed in a thin film
structure according to still another embodiment.
[0104] A dielectric layer 502 includes a first layer 71 including
HfO.sub.2 prepared in i-cycles, a second layer 72 including
ZrO.sub.2 prepared in j-cycles (j>i), and an uppermost layer UP7
including HfO.sub.2 prepared in k-cycles (k>i, j). That is, the
first layer 71 is an HfO.sub.2 layer having a thickness of i*t, the
second layer 72 is a ZrO.sub.2 layer having a thickness of j*t, and
the uppermost layer UP7 is a HfO.sub.2 layer having a thickness of
k*t (k>i, j). Among these layers, the uppermost layer UP7 is
thickest.
[0105] The plurality of first layers 71 and the plurality of second
layers 72 may repeatedly disposed. For example, the first layers 71
and the second layers 72 may repeatedly disposed R times. When the
content of Hf in the dielectric layer 507 is lower than the content
of Zr in the dielectric layer 507, k<R*(j-i) may be satisfied.
For example, k=5, R=3, j=3, and i=1 may be satisfied. In addition,
the dielectric layer 507 may be formed in various forms.
[0106] FIG. 8A is a cross-sectional view illustrating another
example structure of a dielectric layer employed in a thin film
structure according to still another embodiment, and FIG. 8B is an
electron microscope photograph of the dielectric layer of FIG.
8A.
[0107] A dielectric layer 503 includes a first layer 31 including
HfO.sub.2 prepared in i-cycles, and an uppermost layer UP3
including ZrO.sub.2 prepared in j-cycles (j>i). The thicknesses
of the first layer 31 and the uppermost layer UP3 may be i*t and
j*t, respectively. t may be about 0.3 nm to 0.8 nm. j may be 3 or
more. The thickness of the uppermost layer UP3 may be about 25 nm
or more.
[0108] The dielectric layer 503 may further include a second layer
32 disposed on the first layer 31 and including ZrO.sub.2 prepared
in i-cycles, and a third layer 33 disposed on the second layer 32
and including HfO.sub.2 prepared in j-cycles. Pairs of the first
layer 31 and the second layer 32 may be repeatedly disposed under
the third layer 33 several times. The number of repeated times may
be determined in consideration of the overall thickness of the
dielectric layer 503 to be formed.
[0109] In the case where the content ratio of Hf and Zr in the
dielectric layer 503 of the present embodiment is 1:1, the
dielectric layer 503 forms Hf.sub.0.5Zr.sub.0.5O.sub.2. According
to the composition, the first layer 31 and the second layer,
adjacent to each other, are set to have the same thickness, whereas
the uppermost layer UP2 and the third layer 33 adjacent thereto are
set to be thicker than the first layer 31 and the second layer
32.
[0110] The thin film structure shown in FIG. 8B is formed in the
order of Si layer/SiO.sub.2 layer/dielectric layer 503/metal layer
M. In the dielectric layer 503, as shown in FIG. 8A, the first
layers 31 prepared in 1-cycle and the second layers 32 prepared in
1-cycle are repeatedly disposed six times, and each of the third
layer 33 and the uppermost layer UP3 is prepared in 6-cycles to
form Hf.sub.0.5Zr.sub.0.5O.sub.2. The dielectric layer 503 exhibits
good crystallinity as shown in the drawing.
[0111] FIG. 9A is a cross-sectional view illustrating another
example structure of a dielectric layer employed in a thin film
structure according to still another embodiment. FIG. 9B is an
electron microscope photograph of the dielectric layer of FIG.
9A.
[0112] A dielectric layer 504 includes a first layer 41 including
HfO.sub.2 prepared in j-cycles, and an uppermost layer UP4
including ZrO.sub.2 prepared in j-cycles. j may be 3 or more. The
thickness of the uppermost layer UP4 may be about 25 nm or
more.
[0113] The dielectric layer 504 may further include a second layer
42 disposed on the first layer 41 and including ZrO.sub.2 prepared
in j-cycles, and a third layer 43 disposed on the second layer 42
and including HfO.sub.2 prepared in j-cycles. Pairs of the first
layer 41 and the second layer 42 may be repeatedly disposed under
the third layer 43 several times. The number of repeated times may
be determined in consideration of the overall thickness of the
dielectric layer 504 to be formed.
[0114] In the case where the content ratio of Hf and Zr in the
dielectric layer 504 of the present embodiment is 1:1, the
dielectric layer 504 forms Hf.sub.0.5Zr.sub.0.5O.sub.2, and the
plurality of layers are set to have the same thickness.
[0115] FIG. 9B is an electron microscope photograph illustrating a
case where j is set to 4, the first layers and the second layers
are repeatedly formed two times, and the third layer 43 and the
uppermost layer UP3 are formed. That is, FIG. 9B is an electron
microscope photograph illustrating a case where
Hf.sub.0.5Zr.sub.0.5O.sub.2 having a thickness of 12t was
fabricated from the dielectric layer 503 in which the HfO.sub.2
layer and the ZrO.sub.2 layer were laminated three times in
4-cycles. As shown in the drawing, good crystallinity is
exhibited.
[0116] FIG. 10A is a cross-sectional view illustrating another
example structure of a dielectric layer employed in a thin film
structure according to still another embodiment, and FIG. 10B is an
electron microscope photograph of the dielectric layer of FIG.
10A.
[0117] A dielectric layer 505 includes a first layer 51 including
HfO.sub.2 prepared in j-cycles, and an uppermost layer UP5
including ZrO.sub.2 prepared in j-cycles.
[0118] The dielectric layer 505 may further include a second layer
52 disposed on the first layer 51 and including ZrO.sub.2 prepared
in k-cycles (k<j), and a third layer 53 disposed on the second
layer 52 and including HfO.sub.2 prepared in k-cycles (k<j).
Pairs of the second layer 52 and the third layer 53 may be
repeatedly disposed between the first layer 51 and the uppermost
layer UP5. The number of repeated times may be determined in
consideration of the overall thickness of the dielectric layer 505
to be formed.
[0119] In the case where the content ratio of Hf and Zr in the
dielectric layer 505 of the present embodiment, similarly to the
dielectric layers 503 and 504, is 1:1, the dielectric layer 505
forms Hf.sub.0.5Zr.sub.0.5O.sub.2. In the dielectric layer 505 of
the present embodiment, the first layer 51 and the uppermost layer
UP5 are formed to have the same thickness, and the second layers 52
and third layers 53, each being thinner than the uppermost layer
UP5, are repeatedly disposed between the first layer 51 and the
uppermost layer UP5.
[0120] The electron microscope photography of FIG. 10B shows the
dielectric layer 505 in which ZrO.sub.2 layers prepared in 1-cycle
and HfO.sub.2 layers prepared in 1-cycle are repeatedly laminated
five times between a HfO.sub.2 layer prepared in 5-cycles and a
ZrO.sub.2 layer (uppermost layer) prepared in 5-cycles to form
Hf.sub.0.5Zr.sub.0.5O.sub.2. As shown in the drawing, the
dielectric layer 505 exhibits good crystallinity.
[0121] Although it is illustrated in the embodiments of FIGS. 8A,
9A and 10A that the uppermost layer is set as a ZrO.sub.2 layer
when the content of Hf in each of the dielectric layer 503, 504,
and 505 is equal to the content of Zr in each of the dielectric
layer 503, 504, and 505, in another embodiment, even in this case,
the uppermost layer may be set as a ZrO.sub.2 layer, and may be set
to be thickest.
[0122] FIG. 11 is a cross-sectional view illustrating another
example structure of a dielectric layer employed in a thin film
structure according to still another embodiment.
[0123] A dielectric layer 508 includes a first layer 81 including
HfO.sub.2 prepared in i-cycle, a second layer 82 including
ZrO.sub.2 prepared in j-cycle (j>i), and an uppermost layer UP8
including HfO.sub.2 prepared in m-cycles (m>i, j). That is, the
first layer 81 is an HfO.sub.2 layer having a thickness of i*t, the
second layer 82 is a ZrO.sub.2 layer having a thickness of j*t, and
the uppermost layer UP8 is a HfO.sub.2 layer having a thickness of
m*t (m>i, j). Among these layers, the uppermost layer UP8 is
thickest.
[0124] The plurality of first layers 81 and the plurality of second
layers 82 may repeatedly disposed. For example, the first layers 81
and the second layers 82 may repeatedly disposed R times. When the
content of Hf in the dielectric layer 508 is equal to the content
of Zr in the dielectric layer 508, m=R*(j-i) may be satisfied. For
example, m=6, R=3, j=3, and i=1 may be satisfied. In addition, the
dielectric layer 508 may be formed in various forms.
[0125] FIG. 12A is a cross-sectional view illustrating another
example structure of a dielectric layer employed in a thin film
structure according to still another embodiment. FIG. 12B is an
electron microscope photograph of the dielectric layer of FIG.
12A.
[0126] A dielectric layer 506 of the present embodiment is
different from the aforementioned embodiments in that a>b is
satisfied when the content ratio of Hf and Zr is a:b.
[0127] The dielectric layer 506 includes a first layer 61 including
ZrO.sub.2 prepared in i-cycles and having a thickness of i*t (i is
an integer, and t is a real number), and an uppermost layer UP6
including HfO.sub.2 prepared in j-cycles and having a thickness of
j*t (j>i, j is an integer of 3 or more).
[0128] The dielectric layer 506 may further include a second layer
62 disposed on the first layer 61, having a thickness of j*t and
including HfO.sub.2, and a third layer 63 disposed on the second
layer 62, having a thickness of i*t and including ZrO.sub.2. Pairs
of the second layer 62 and the third layer 63 may be repeatedly
disposed between the first layer 62 and the uppermost layer UP6
several times.
[0129] FIG. 12B is an electron microscope photograph of the
dielectric layer 506 of FIG. 12A, and illustrates a case where i=1
and j=4 are satisfied, and pairs of HfO.sub.2 1-cycle and ZrO.sub.2
4-cycles are repeated five times. The thin film shown in FIG. 12B
is formed in the order of Si layer/SiO.sub.2 layer/dielectric layer
506/metal layer M. The dielectric layer 502 forms
Hf.sub.0.8Zr.sub.0.2O.sub.2. The dielectric layer 506 exhibits good
crystallinity as shown in the drawing.
[0130] FIG. 13 is a cross-sectional view illustrating an example
structure of a comparative dielectric layer to be compared with the
dielectric layer of FIG. 12A.
[0131] A dielectric layer 55 is configured such that pairs of a
HfO.sub.2 layer 3 prepared in 4-cycles and a ZrO.sub.2 layer
prepared in 1-cycle are repeatedly disposed, and is different from
the aforementioned dielectric layer 506 in the placement order of
the pairs thereof. Unlike the aforementioned dielectric layer 506,
the comparative dielectric layer 55 is configured such that its
uppermost layer thereof is formed as the ZrO.sub.2 layer 4 thinner
than the HfO.sub.2 layer 3.
[0132] FIG. 14 is a graph comparing a dielectric constant of the
dielectric layer of FIG. 12A with a dielectric constant of the
comparative dielectric layer 5 of FIG. 11.
[0133] Referring to FIG. 14, it may be found that, even in the
cases of Hf.sub.0.8Zr.sub.0.2O.sub.2 having the same composition,
the dielectric constant is changed depending on the method and the
resulting structure. It may be found that the dielectric constant
of the dielectric layer 506 in which a thick HfO.sub.2 layer is
disposed as the uppermost layer UP6 is higher than that of the
comparative dielectric layer 5.
[0134] The reason for this is analyzed in that the kind and
thickness of the uppermost layer UP6 contacting the conductive
material disposed on the dielectric layer 506 are appropriately
set, thereby making the crystallinity of
Hf.sub.0.8Zr.sub.0.2O.sub.2 good.
[0135] Although it is illustrated in the embodiment of FIG. 12A
that the uppermost layer is set as a HfO.sub.2 layer when the
content of Hf in the dielectric layer 506 is higher than the
content of Zr in the dielectric layer 506, in another embodiment,
even in this case, the uppermost layer may be set as a ZrO.sub.2
layer, and may be set to be thickest.
[0136] FIG. 15 is a cross-sectional view illustrating another
example structure of a dielectric layer employed in a thin film
structure according to still another embodiment.
[0137] A dielectric layer 509 includes a first layer 91 including
ZrO.sub.2 prepared in j-cycles, a second layer 92 including
HfO.sub.2 prepared in i-cycles (i>j), and an uppermost layer UP9
including ZrO.sub.2 prepared in n-cycles (n>i, j). That is, the
first layer 91 is a ZrO.sub.2 layer having a thickness of j*t, the
second layer 92 is a HfO.sub.2 layer having a thickness of i*t, and
the uppermost layer UP9 is a ZrO.sub.2 layer having a thickness of
n*t (n>i, j). Among these layers, the uppermost layer UP9 is
thickest.
[0138] The plurality of first layers 91 and the plurality of second
layers 92 may repeatedly disposed. For example, the first layers 91
and the second layers 92 may repeatedly disposed R times. When the
content of Hf in the dielectric layer 509 is higher than the
content of Zr in the dielectric layer 509, n<R*(j-i) may be
satisfied. For example, n=5, R=3, j=3, and l=1 may be satisfied. In
addition, the dielectric layer 509 may be formed in various
forms.
[0139] FIG. 16 is a flowchart schematically illustrating operations
of a method of manufacturing a thin film structure according to an
embodiment.
[0140] The method of manufacturing a thin film structure according
to an embodiment includes the operations of: providing a substrate
(S100); forming a dielectric layer on the substrate (S200); and
forming a conductive layer on the dielectric layer (S500).
[0141] The substrate is a target substrate on which the dielectric
layer is to be formed, and the kind thereof is not limited
thereto.
[0142] The dielectric layer is formed of a plurality of layer
including a dopant layer containing a dopant A and a HfO.sub.2
layer, to form a compound of Hf.sub.aA.sub.bO.sub.z. In this case,
among the plurality of layers, the uppermost layer thereof is
formed to be thickest.
[0143] The dopant A may include any one of transition metals such
as Zr, La, and Y, Si, Al, and Sn, and may be made of binary or
ternary or more. The dopant layer may include any one of transition
metal-based oxide such as ZrO.sub.2, LaO.sub.2, or YO.sub.2, and
SiO.sub.2, Al.sub.2O.sub.3, and SnO.sub.2.
[0144] The conductive layer may include any one of a metal such as
TiN, W, Mo, or Ni; a conductive oxide such as RuO.sub.2,
SrRuO.sub.3, or ITO; and a 2D material such as graphene. The
conductive layer may include metal nitride or metal oxynitride.
[0145] In order to form the dielectric layer and the conductive
layer, deposition methods, such as atomic layer deposition (ALD),
metal organic atomic layer deposition (MOALD), chemical vapor
deposition (CVD), metal organic chemical vapor deposition (MOCVD),
and physical vapor deposition (PVD) may be used.
[0146] In order to form the dielectric layer, first, the operation
S210 of determining the composition ratio a:b of Hf and A and
determining the total thickness; the operation S230 of setting the
uppermost layer; and the operation S250 of repeating the cycles of
the HfO.sub.2 layer and the A-dopant layer may be performed.
[0147] The operation S230 of setting the uppermost layer is a
procedure of determining the kind and thickness of the uppermost
layer to obtain an optimal dielectric constant in the composition
ratio and thickness defined in consideration of the determined a:b
and total thickness. As in the explanation of the aforementioned
dielectric layers 500 to 509, the uppermost layer may be determined
so as to prepare a compound of Hf.sub.aA.sub.bO.sub.z having good
crystallinity.
[0148] For example, when the content ration is a:b, the uppermost
layer may be set as an A-dopant layer in the case of a.ltoreq.b,
and the uppermost layer may be set as a HfO.sub.2 layer in the case
of a>b. Alternatively, the uppermost layer may be set as a
HfO.sub.2 layer even in the case of a.ltoreq.b, and the uppermost
layer may be set as an A-dopant layer even in the case of a>b.
Next, in order for the uppermost layer to have the maximum
thickness, the thicknesses, repetition number and positions of
other layers, that is, the HfO.sub.2 layer and the A-dopant layer
may be set in consideration of the total content ratio and process
conditions.
[0149] After the dielectric layer is formed, heat treatment may be
performed (S300). However, this operation may be omitted.
[0150] Next, after the conductive layer is formed on the dielectric
layer, heat treatment may be performed (S500). This heat treatment
is used for accelerating the crystallization of the dielectric
layer. Here, both operations may be performed, or only one
operation may be selectively performed.
[0151] FIG. 17 is a cross-sectional view illustrating the schematic
structure of an electronic device according to an embodiment.
[0152] An electronic device 2000 may include a semiconductor layer
100, an insulating layer 200 formed on the semiconductor layer 100,
a dielectric layer 500 formed on the insulating layer 200, and a
first conductive layer 700 formed on the dielectric layer 500.
[0153] The semiconductor layer 100 may include a semiconductor
substrate. The semiconductor substrate may include a silicon
substrate, a germanium substrate, or a silicon-germanium substrate.
The semiconductor layer 100 may include at least one selected from
Al, Si, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Rb, Sr, Y,
Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, In, Sn, Sb, Te, Cs, Ba, Hf, Ta,
W, Re, Os, Ir, Pt, and Au, or may include a nitride or oxide of the
at least one.
[0154] The insulating layer 200 may be a layer for suppressing or
preventing electrical leakage. As the insulating layer 200, a
silicon oxide (SiO) layer, an aluminum oxide (AlO) layer, a hafnium
oxide (HfO) layer, a zirconium oxide (ZrO) layer, or a
two-dimensional (2D) insulator may be used. As the 2D insulator, a
material such as hexagonal boron nitride (h-BN) may be used.
However, the material of the insulating layer 200 is not limited
thereto.
[0155] The dielectric layer 500 may be any one of the
aforementioned dielectric layers 500, 501, 502, 503, 504, 505, and
506. The dielectric layer 500 may function as a ferroelectric
domain switching layer.
[0156] The first conductive layer 700 may include any one of a
metal such as TiN, W, Mo, or Ni; a conductive oxide such as
RuO.sub.2, SrRuO.sub.3, or ITO; and a 2D material such as graphene.
The conductive layer may include metal nitride or metal
oxynitride.
[0157] The first conductive layer 700 may be a gate electrode. A
source electrode (not shown) and a drain electrode (not shown) may
be connected to the semiconductor layer 100. A source region (not
shown) and a drain region (not shown) may be provided on the
semiconductor layer 100, and a source electrode and a drain
electrode may be connected to the source region and the drain
region, respectively. A channel region, which is a region of the
semiconductor layer, may be disposed between the source region and
the drain region.
[0158] The aforementioned electronic device 2000 may be a logic
transistor.
[0159] FIG. 18 is a cross-sectional view illustrating the schematic
structure of an electronic device according to another
embodiment.
[0160] An electronic device 3000 of the present embodiment is
different from the electronic device 2000 of FIG. 17 in that an
insulating layer is not provided, and is substantially the same as
the electronic device 2000 of FIG. 17 in other components.
[0161] FIG. 19 is a cross-sectional view illustrating the schematic
structure of an electronic device according to still another
embodiment.
[0162] An electronic device 4000 of the present embodiment is
different from the electronic device 2000 of FIG. 17 in that a
second conductive layer 300 is further provided, and is
substantially the same as the electronic device 2000 of FIG. 17 in
other components.
[0163] The electronic devices of FIGS. 17 to 19 may function as
transistor devices.
[0164] FIG. 20 is a cross-sectional view illustrating the schematic
structure of an electronic device according to still another
embodiment.
[0165] An electronic device 5000 includes a second conductive layer
900, a dielectric layer 500 formed on the second conductive layer
900, and a first conductive layer 700 formed on the dielectric
layer 500. The dielectric layer 500 may be any one of the
aforementioned dielectric layers 500, 501, 502, 503, 504, 505, and
506.
[0166] FIG. 21 is a cross-sectional view illustrating the schematic
structure of an electronic device according to still another
embodiment.
[0167] An electronic device 6000 of the present embodiment is
different from the electronic device 5000 of FIG. 20 in that an
insulating layer 200 is further provided between the second
conductive layer 900 and the dielectric layer 500, and is
substantially the same as the electronic device 5000 of FIG. 20 in
other components.
[0168] The electronic devices 5000 and 6000 of FIGS. 20 and 21 may
be capacitors, and may include a high dielectric constant
dielectric layer 5000 to exhibit high capacitance.
[0169] FIG. 22 is a cross-sectional view illustrating the schematic
structure of an electronic device according to still another
embodiment.
[0170] Referring to FIG. 22, in an embodiment, an electronic device
7000 may include a substrate SUB including source/drain regions S/D
spaced apart from each other, a transistor structure Tr on the
substrate SUB between the source/drain regions S/D, an insulation
film 800 on the substrate SUB and transistor structure Tr, a
capacitor C on the insulation film 800, and a contact 820 extending
through the insulation film 800 to electrically connect the
capacitor C to one of the source/drain regions S/D. The substrate
SUB may be the same as the substrate 100 in FIGS. 17-19. The
insulation film 800 may be an insulating material (e.g., silicon
oxide). The source/drain region S/D may be regions of the substrate
SUB doped with impurities. The capacitor C may be one of the
electronic devices 5000 and 6000 in FIGS. 20 and 21, but is not
limited thereto. The transistor structure Tr may be one of the
electronic devices 2000, 3000, and 4000 in FIGS. 17-19, but is not
limited thereto.
[0171] The aforementioned electronic devices 2000, 3000, 4000,
5000, 6000, and 7000 may form integrated devices. The integrated
device may form a part of a silicon-based integrated circuit, and
this integrated circuit may include a plurality of capacitors, a
plurality of transistors, and a plurality of memory devices. Such a
device may be provided with a dielectric layer having high
dielectric constant or ferroelectricity, thereby achieving desired
high performance and miniaturization.
[0172] According to the above-described thin film structure and
manufacturing method thereof, a dielectric layer having good
crystallinity and high dielectric constant is provided.
[0173] The above-described thin film structure may be employed in
various electronic devices such as transistors, capacitors,
integrated circuit devices, and such electronic devices may exhibit
good operating performance.
[0174] It should be understood that embodiments described herein
should be considered in a descriptive sense only and not for
purposes of limitation. Descriptions of features or aspects within
each embodiment should typically be considered as available for
other similar features or aspects in other embodiments. While one
or more embodiments have been described with reference to the
figures, it will be understood by those of ordinary skill in the
art that various changes in form and details may be made therein
without departing from the spirit and scope as defined by the
following claims.
* * * * *