U.S. patent application number 11/790445 was filed with the patent office on 2008-03-06 for method of forming a thin film and methods of manufacturing a gate structure and a capacitor using same.
Invention is credited to Jun-Hyun Cho, Kyoo-Chul Cho, Youn-Joung Cho, Jung-Sik Choi, Jung-Ho Lee, Seung-Min Ryu.
Application Number | 20080057224 11/790445 |
Document ID | / |
Family ID | 39151979 |
Filed Date | 2008-03-06 |
United States Patent
Application |
20080057224 |
Kind Code |
A1 |
Cho; Youn-Joung ; et
al. |
March 6, 2008 |
Method of forming a thin film and methods of manufacturing a gate
structure and a capacitor using same
Abstract
A method of manufacturing a thin film includes providing a metal
organic precursor onto a substrate where the metal organic
precursor is heated to a temperature of about 60.degree. C. to
about 95.degree. C. and has a saturated vapor pressure of about 1
Torr to about 5 Torr. An oxidizing agent including oxygen for
oxidizing the metal organic precursor is provided onto the
substrate. The metal organic precursor and the oxidizing agent are
chemically reacted to form the thin film including metal oxide. The
thin film is easily available in a gate insulation layer of a gate
structure, a dielectric layer of a capacitor, and similar circuit
components.
Inventors: |
Cho; Youn-Joung;
(Gyeonggi-do, KR) ; Lee; Jung-Ho; (Gyeonggi-do,
KR) ; Cho; Jun-Hyun; (Gyeonggi-do, KR) ; Ryu;
Seung-Min; (Busan, KR) ; Cho; Kyoo-Chul;
(Gyeonggi-do, KR) ; Choi; Jung-Sik; (Gyeonggi-do,
KR) |
Correspondence
Address: |
VOLENTINE & WHITT PLLC
ONE FREEDOM SQUARE, 11951 FREEDOM DRIVE SUITE 1260
RESTON
VA
20190
US
|
Family ID: |
39151979 |
Appl. No.: |
11/790445 |
Filed: |
April 25, 2007 |
Current U.S.
Class: |
427/585 |
Current CPC
Class: |
C23C 4/123 20160101;
C23C 8/02 20130101; C23C 8/80 20130101 |
Class at
Publication: |
427/585 |
International
Class: |
C23C 8/00 20060101
C23C008/00 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 30, 2006 |
KR |
2006-83075 |
Claims
1. A method of forming a thin film comprising: providing a metal
organic precursor onto a substrate, wherein the metal organic
precursor has a saturated vapor pressure of about 1 Torr to about 5
Torr when the metal organic precursor is heated to a temperature of
about 60.degree. C. to about 90.degree. C.; providing an oxidizing
agent including oxygen onto the substrate, the oxidizing agent
configured to oxidize the metal organic precursor; and forming the
thin film including a metal oxide on the substrate by chemically
reacting the metal organic precursor with the oxidizing agent.
2. The method of claim 1, wherein providing a metal organic
precursor is represented by R3-N=M(N(R1)(R2))2 wherein R1, R2 and
R3 independently represent hydrogen or an alkyl group having one to
five carbon atoms, and M represents zirconium or hafnium.
3. The method of claim 1, wherein the metal organic precursor
comprises tertiary-butyl-imido bis-methyl-ethyl-amino hafnium
[(t-BuN)Hf(N(CH3)(C2H5))2].
4. The method of claim 1, wherein the metal organic precursor
comprises tertiary-butyl-imido bis-metyl-ethyl-amino zirconium
[(t-BuN)Zr(N(CH3)(C2H5))2].
5. The method of claim 1, wherein the metal organic precursor is in
a gaseous state having a saturated vapor pressure of about 3 Torr
to about 5 Torr, the precursor formed by heating the precursor in a
liquid state at a temperature of about 75.degree. C. to about
85.degree. C. in a canister.
6. The method of claim 1, wherein the metal organic precursor is
provided onto the substrate with at least one carrier gas selected
from the group consisting essentially of argon gas, nitrogen gas
and helium gas.
7. The method of claim 1, further comprising: performing a first
purge process on the substrate using a purge gas after the metal
organic precursor is provided onto the substrate, and performing a
second purge process on the substrate using the purge gas after the
oxidizing agent is provided onto the substrate.
8. The method of claim 7, wherein the thin film is formed at a
temperature of about 250.degree. C. to about 400.degree. C. under a
pressure of about 0.5 Torr to about 3.0 Torr.
9. The method of claim 8, wherein the metal organic precursor is
provided onto the substrate by a liquid delivery system, the method
further comprising vaporizing the metal organic precursor at a
temperature of about 100.degree. C. to about 150.degree. C. in the
liquid delivery system.
10. A method of forming a thin film including metal-aluminum oxide,
the method comprising: (a) providing a first reactive material
including a metal organic precursor onto a substrate, the metal
organic precursor having a saturated vapor pressure of about 1 Torr
to about 5 Torr when the precursor is heated to a temperature of
about 60.degree. C. to about 95.degree. C., the metal organic
precursor represented by R3-N=M(N(R1)(R2))2 wherein R1, R2 and R3
independently represent hydrogen or an alkyl group having one to
five carbon atoms, and M represents zirconium or hafnium. (b)
chemically adsorbing a first portion of the first reactive material
onto the substrate and physically adsorbing a second portion of the
first reactive material onto the substrate; (c) providing an
oxidizing agent including oxygen onto the substrate; (d) forming a
first solid material including a metal oxide on the substrate by
chemically reacting the first portion of the first reactive
material with the oxidizing agent; (e) providing a second reactive
material including an aluminum organic precursor onto the first
solid material; (f) chemically adsorbing a first portion of the
second reactive material onto the first solid material and
physically adsorbing a second portion of the second reactive
material onto the first solid material; (g) providing an oxidizing
agent onto the first solid material; and (h) forming a second solid
material including aluminum oxide on the first solid material by
chemically reacting the first portion of the second reactive
material with the oxidizing agent,
11. The method of claim 10, further comprising: removing the second
portion of the first reactive material physically adsorbed on the
substrate; removing a portion of the oxidizing agent, the portion
configured not reactive with the first portion of the first
reactive material; removing the second portion of the second
reactive material physically adsorbed on the substrate; and
removing a portion of the oxidizing agent, the portion configured
not reactive with the first portion of the second reactive
material.
12. The method of claim 10, wherein steps (a)-(d) are repeatedly
performed at least once, respectively.
13. The method of claim 10, wherein steps (e)-(h) are repeatedly
performed at least once.
14. The method of claim 10, wherein steps (a)-(h) are repeatedly
performed at least once.
15. The method of claim 10, wherein the metal organic precursor
comprises tertiary-butyl-imido bis-methyl-ethyl-amino hafnium
[(t-BuN)Hf(N(CH3)(C2H5))2] tertiary-butyl-imido
bis-metyl-ethyl-amino zirconium [(t-BuN)Zr(N(CH3)(C2H5))2].
16. The method of claim 10, wherein the metal organic precursor
comprises tertiary-butyl-imido bis-metyl-ethyl-amino zirconium
[(t-BuN)Zr(N(CH3)(C2H5))2].
17. A method of manufacturing a gate structure of a semiconductor
device, the method comprising: providing a metal organic precursor
onto a substrate, wherein the metal organic precursor has a
saturated vapor pressure of about 1 Torr to about 5 Torr when the
metal organic precursor is heated to a temperature of about
60.degree. C. to about 95.degree. C. in a canister, the metal
organic precursor represented by R3-N=M(N(R1)(R2))2 where R1, R2
and R3 independently represent hydrogen or an alkyl group having
one to five carbon atoms, and M represents zirconium or hafnium;
providing an oxidizing agent including oxygen onto the substrate,
the oxidizing agent configured to oxidize the metal organic
precursor; forming a gate insulation layer including a metal oxide
on the substrate by chemically reacting the metal organic precursor
with the oxidizing agent provided on the substrate; forming a
conductive layer on the gate insulation layer; and forming the gate
structure including a gate insulation layer pattern and a gate
conductive pattern sequentially stacked on the substrate by
patterning the conductive layer and the gate insulation layer.
18. A method of manufacturing a capacitor, comprising: forming a
lower electrode on a substrate; providing a metal organic onto the
substrate, wherein the metal organic precursor has a saturated
vapor pressure of about 1 Torr to about 5 Torr when the metal
organic precursor is heated up to a temperature of about 60.degree.
C. to about 95.degree. C., the metal organic precursor represented
by R3-N=M(N(R1)(R2))2 where R1, R2 and R3 independently represent
hydrogen or an alkyl group having one to five carbon atoms, and M
represents zirconium or hafnium; providing an oxidizing agent
including oxygen onto the substrate, the oxidizing agent configured
to oxidize the metal organic precursor; forming a dielectric layer
including a metal oxide on the lower electrode by chemically
reacting the metal organic precursor with the oxidizing agent
provided on the substrate; and forming an upper electrode on the
dielectric layer.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] Example embodiments of the present invention relate to a
method of forming a thin film utilizing a metal organic precursor
and methods of manufacturing a gate structure and a capacitor using
the thin film method.
[0003] This U.S. non-provisional patent application claims priority
under 35 U.S.C. .sctn. 119 to Korean Patent Application No.
2006-0083075 filed on Aug. 30, 2006, the entire contents of which
are hereby incorporated by reference.
[0004] 2. Discussion of Related Art
[0005] Thin films having a high dielectric constant have been used
to form gate insulation layers of a metal oxide semiconductor (MOS)
transistor, dielectric layers of a capacitor in a semiconductor
device and dielectric layers of a flash memory device. When the
film is formed using the material having the high dielectric
constant, the film may have a thin equivalent oxide thickness
(EOT). Additionally, leakage current generated between a gate
electrode and a channel layer or between a lower electrode and an
upper electrode may be sufficiently reduced, and a coupling ratio
of a flash memory device may be improved. Examples of the material
having the high dielectric constant may include tantalum oxide,
yttrium oxide, hafnium oxide, zirconium oxide, niobium oxide,
barium titanium oxide, strontium titanium oxide, etc.
[0006] The hafnium oxide layer may be formed using a hafnium
precursor and an oxidant where the hafnium precursor may include
tetrakis-ethyl-methyl-amino hafnium (TEMAH, Hf(NC2H5CH3)4),
hafnium-tetrakis butoxide [HTTB, Hf(OC4H9)4], etc. When TEMAH is
used as the hafnium precursor, it is heated in a canister to a
temperature of about 90.degree. C. into a gaseous state and a
saturated vapor pressure in the canister maintains a low value of
at most about 1 Torr. When TEMAH has a low saturated vapor
pressure, delivering the hafnium precursor into a process chamber
to form the hafnium oxide layer requires additional time. This
additional delivery time reduces the throughput of a semiconductor
manufacturing process. Further, TEMAH may deteriorate when it is
heated to a temperature above about 90.degree. C. Thus, raising the
saturated vapor pressure of the hafnium precursor has its
limitation.
[0007] Accordingly, a novel metal organic precursor and a method of
forming a metal oxide layer using the novel metal organic precursor
are needed to manufacture a metal oxide layer having substantially
the same dielectric characteristics as those of a conventional
metal oxide layer and to manufacture a metal oxide layer more
productively. In addition, the metal organic precursor used is
required to have a saturated vapor pressure above about 1 Torr at a
temperature below about 90.degree. C. and to have a good reactivity
with an oxidizing agent.
SUMMARY OF THE INVENTION
[0008] Example embodiments of the present invention are directed to
a method of forming a thin film including metal oxide. The thin
film has electrical characteristics similar to those of a hafnium
oxide layer formed using TEMAH and increases the throughput of a
semiconductor manufacturing process. The thin film method includes
providing a metal organic precursor onto a substrate. The metal
organic precursor has a saturated vapor pressure of about 1 Torr to
about 5 Torr when the metal organic precursor is heated to a
temperature of about 60.degree. C. to about 90.degree. C. An
oxidizing agent that includes oxygen is provided onto the substrate
and is configured to oxidize the metal organic precursor. The metal
organic precursor is chemically reacted with the oxidizing agent to
form the thin film including a metal oxide on the substrate.
[0009] According to one aspect of the present invention, there is
provided a method of forming a thin film. In the method of forming
the thin film, a metal organic precursor represented by a formula
(1) is provided onto a substrate. The metal organic precursor has a
saturated vapor pressure of about 1 Torr to about 5 Torr when the
metal organic precursor is heated upto a temperature of about
60.degree. C. to about 90.degree. C. An oxidizing agent including
oxygen for oxidizing the metal organic precursor is provided onto
the substrate. The thin film including metal oxide is formed on the
substrate by chemically reacting the metal organic precursor with
the oxidizing agent.
[0010] According to another aspect of the present invention, there
is provided a method of forming a thin film. In the method of
forming the thin film, a first reactive material including a metal
organic precursor represented by a formula (1) is provided onto a
substrate. The metal organic precursor has a saturated vapor
pressure of about 1 Torr to about 5 Torr when the metal organic
precursor is heated upto a temperature of about 60.degree. C. to
about 95.degree. C. A first portion of the first reactive material
is chemically adsorbed onto the substrate and a second portion of
the first reactive material is physically adsorbed onto the
substrate. An oxidizing agent including oxygen is provided onto the
substrate. A first solid material including a metal oxide is formed
on the substrate by chemically reacting the first portion of the
first reactive material with the oxidizing agent. A second reactive
material including an aluminum organic precursor is provided onto
the first solid material. A first portion of the second reactive
material is chemically adsorbed onto the first solid material and a
second portion of the second reactive material is physically
absorbed onto the first solid material. An oxidizing agent is
provided onto the first solid material. A second solid material
including aluminum oxide is formed on the first solid material by
chemically reacting the first portion of the second reactive
material with the oxidizing agent. As a result, a solid material
including metal-aluminum oxide is completed.
R3-N=M(N(R1)(R2))2 (1)
[0011] Here, R1, R2 and R3 independently represent hydrogen or an
alkyl group having one to five carbon atoms, and M represents
zirconium or hafnium.
[0012] According to still another aspect of the present invention,
there is provided a method of manufacturing a gate structure of a
semiconductor device. In the method of manufacturing a gate
structure of a semiconductor device, a metal organic precursor
represented by a formula (2) is provided on a substrate. The metal
organic precursor has a saturated vapor pressure of about 1 Torr to
about 5 Torr when the metal organic precursor is heated upto a
temperature of about 60.degree. C. to about 95.degree. C. in a
canister. An oxidizing agent including oxygen for oxidizing the
metal organic precursor is provided onto the substrate. A gate
insulation layer including metal oxide is formed on the substrate
by chemically reacting the metal organic precursor with the
oxidizing agent. A conductive layer is formed on the gate
insulation layer. A gate structure including and a gate insulation
layer pattern and a gate conductive pattern is formed on the
substrate by patterning the conductive layer and the gate
insulation layer.
[0013] According to still another aspect of the present invention,
there is provided a method of manufacturing a capacitor of a
semiconductor device. In the method of manufacturing the capacitor
of the semiconductor device, a lower electrode is formed on a
substrate. A metal organic precursor represented by a formula (2)
is provided onto the substrate. The metal organic precursor is
heated upto a temperature of about 60.degree. C. to about
95.degree. C., and has a saturated vapor pressure of about 1 Torr
to about 5 Torr. An oxidizing agent including oxygen for oxidizing
the metal organic precursor is provided onto the substrate. A
dielectric layer including a metal oxide is formed on the lower
electrode by chemically reacting the metal organic precursor with
the oxidizing agent. An upper electrode is formed on the dielectric
layer. As a result, a capacitor including the lower electrode, a
dielectric layer that includes the metal oxide and the upper
electrode is formed on the substrate.
R3-N=M(N(R1)(R2))2 (2)
[0014] Here, R1, R2 and R3 independently represent hydrogen or an
alkyl group having one to five carbon atoms, and M represents
zirconium or hafnium.
[0015] In an example embodiment of the present invention, the metal
organic precursor in a gaseous state may be formed by heating a
metal organic precursor in a liquid state at a temperature of about
75.degree. C. to about 85.degree. C. in a canister, and the metal
organic precursor in the gaseous state may have a saturated vapor
pressure of about 3 Torr to about 5 Torr.
[0016] In an example embodiment of the present invention, the metal
organic precursor may be provided onto the substrate with a carrier
gas. Examples of the carrier gas may include argon gas, nitrogen
gas, helium gas, etc.
[0017] In an example embodiment of the present invention, a first
purge process using a purge gas may be further performed on the
substrate after the metal organic precursor is provided onto the
substrate, and a second purge process using the purge gas may be
further performed on the substrate after the oxidizing agent is
provided onto the substrate. The thin film may be formed at a
temperature of about 250.degree. C. to about 400.degree. C. and
under a pressure of about 0.5 Torr to about 3.0 Torr.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIGS. 1 to 5 are cross-sectional views illustrating a method
of forming a thin film in accordance with embodiments of the
present invention;
[0019] FIG. 6 is a flow chart illustrating a method of forming a
thin film in accordance with embodiments of the present
invention;
[0020] FIGS. 7-10 are cross-sectional views illustrating methods of
manufacturing a gate structure in accordance with embodiments of
the present invention;
[0021] FIGS. 11-14 are cross-sectional views illustrating methods
of manufacturing a capacitor in accordance with embodiments of the
present invention;
[0022] FIG. 15 is a graph illustrating changes in saturated vapor
pressures of hafnium precursors according to a change in
temperature;
[0023] FIG. 16 is a graph illustrating a change in a saturated
vapor pressure of zirconium precursor according to a change in
temperature;
[0024] FIG. 17 is a graph illustrating results of
thermo-gravimetric analysis (TGA) in TEMAH and tertiary-butyl-imido
bis-metyl-ethyl-amino zirconium;
[0025] FIG. 18 is a graph illustrating a leakage current of a
capacitor having a hafnium oxide layer as a dielectric layer in
accordance with an embodiment of the present invention;
[0026] FIG. 19 is a graph illustrating a leakage current of a
capacitor formed using a zirconium-aluminum oxide layer in
accordance with an embodiment of the present invention; and
[0027] FIG. 20 is a graph illustrating step coverage of zirconium
oxide layers in accordance with an embodiment of the present
invention.
DESCRIPTION OF EMBODIMENTS
[0028] The present invention will now be described more fully
hereinafter with reference to the accompanying drawings, in which
preferred embodiments of the invention are shown. This invention,
however, may be embodied in many different forms and should not be
construed as limited to the embodiments set forth herein. Rather,
these embodiments are provided so that this disclosure will be
thorough and complete, and will fully convey the scope of the
invention to those skilled in the art. In the drawings, like
numbers refer to like elements throughout.
[0029] It will be understood that, although the terms first,
second, third etc. may be used herein to describe various elements,
components, regions, layers and/or sections, these elements,
components, regions, layers and/or sections should not be limited
by these terms. These terms are only used to distinguish one
element, component, region, layer or section from another region,
layer or section. Furthermore, spatially relative terms, such as
"beneath," "below," "lower," "above," "upper" and the like, may be
used herein for ease of description to describe one element or
feature in relation to another element(s) or feature(s) as
illustrated in the figures. It will be understood that the
spatially relative terms are intended to encompass different
orientations of the device in use or operation in addition to the
orientation depicted in the figures. For example, if the device in
the figures is turned over, elements described as "below" or
"beneath" other elements or features would then be oriented "above"
the other elements or features. Thus, the example term "below" can
encompass both an orientation of above and below. The device may
otherwise be oriented (rotated 90 degrees or at other orientations)
and the spatially relative descriptors used herein interpreted
accordingly.
Method of Forming a Thin Film
[0030] FIGS. 1 to 5 are cross-sectional views illustrating a method
for forming a thin film on a substrate 10 in a process chamber 50.
When an internal temperature of the process chamber 50 is under
about 250.degree. C., a reactivity of a metal organic precursor in
a gaseous state may be disadvantageously low in subsequent
processes. When the internal temperature of the process chamber 50
is over about 450.degree. C., the thin film formed on the substrate
10 may be disadvantageously crystallized and deposited with
characteristics of chemical vapor deposition (CVD). Therefore, the
internal temperature of the process chamber 50 should be in the
range of about 250.degree. C. to about 450.degree. C. and
preferably in the range of about 250.degree. C. to about
400.degree. C. By way of example, a thin film formed in the process
chamber 50 at a temperature of about 300.degree. C. exhibits good
characteristics of atomic layer deposition (ALD).
[0031] When an internal pressure of the process chamber 50 is under
about 0.5 Torr, reactivity of the metal organic precursor in
subsequent processes may be disadvantageously low. However, when
the internal pressure of the process chamber 50 is over about 0.3
Torr, a process for forming the thin film is not easily controlled.
Therefore, the internal pressure of the process chamber 50 should
be in the range of about 0.5 Torr to 3.0 Torr and preferably in the
range of about 0.05 Torr to about 2.0 Torr. By way of example, a
thin film formed under an internal pressure of the process chamber
50 at about 1.0 Torr exhibits good characteristics of an ALD.
[0032] A metal organic precursor represented by formula (1)
(identified below) is provided into the process chamber 50 at the
above-mentioned temperature and pressure. The metal organic
precursor may be provided into the process chamber 50 using a
canister or a liquid delivery system for about 0.5 seconds to 5
seconds. For example, the metal organic precursor is provided into
the process chamber 50 and vaporized at a temperature of about
100.degree. C. to about 150.degree. C. for approximately 1 second.
As a result, a first portion 12 of the metal organic precursor may
be chemically adsorbed (chemisorbed) onto the substrate 10, and a
second portion 14 (i.e., a remaining portion of the metal organic
precursor excluding the first portion 12) may be physically
adsorbed (physisorbed) onto the first portion 12 to have a weak
bonding, or the second portion 14 may be floated in the process
chamber 50. Some portions of the metal organic precursor
chemisorbed on the substrate 10 may be decomposed by internal heat
of the process chamber 50. Therefore, a core metal of the metal
organic precursor may be chemisorbed on the substrate 10 and some
ligands coupled with the core metal may be separated from the core
metal. The metal organic precursor is represented by:
R3-N=M(N(R1)(R2))2 (1)
where R1, R2 and R3 independently represent hydrogen or an alkyl
group having one to five carbon atoms, and M represents titanium,
zirconium or hafnium. For example, R1, R2 and R3 may independently
include a methyl group, an ethyl group, a prophyl group, a tertiary
butyl group, etc. The metal organic precursor represented by
formula (1) may include tertiary-butyl-imido bis-methyl-ethyl-amino
hafnium [(t-BuN)Hf(N(CH3)(C2H5))2] or tertiary-butyl-imido
bis-metyl-ethyl-amino zirconium [(t-BuN)Zr(N(CH3)(C2H5))2]. The
metal organic precursor may be in a liquid state at room
temperature and may be vaporized into a gaseous state at a
temperature of about 60.degree. C. to about 95.degree. C., thereby
generating inert gas bubbles. When the metal organic precursor is
vaporized in a canister, the vaporized precursor may have a
saturated vapor pressure of about 1 Torr to 5 Torr. In other words,
the metal organic precursor may be generated until the metal
organic precursor in the gaseous state becomes saturated.
[0033] When the metal organic precursor in the liquid state
represented by formula (1) is heated to a temperature of about
65.degree. C. to about 75.degree. C. in the canister, a vaporized
metal organic precursor may have a saturated vapor pressure of
about 1 to about 3 Torr. The metal organic precursor may include,
for example, a hafnium precursor or a zirconium precursor. When the
metal organic precursor in the liquid state is heated to about
85.degree. C. to about 95.degree. C., it is vaporized and has a
saturated vapor pressure of about 3 to about 5 Torr. Thus, the
metal organic precursor represented by formula (1) has a higher
saturated vapor pressure than that of a conventional hafnium
precursor such as TEMAH, and the metal organic precursor may have
good reactivity with an oxidizing agent. The time required for
providing the metal organic precursor into a process chamber to
form a thin film may be reduced. Additionally, less of a carrier
gas provided along with the vaporized metal organic precursor may
be consumed and the amount of metal organic precursor provided into
the process chamber may also be reduced. In this manner, when the
metal organic precursor represented by formula (1) is employed in a
thin film, a thin film having a relatively higher dielectric
constant and a relatively lower leakage current than conventional
thin films may be manufactured. Consequently, the throughput of a
semiconductor manufacturing process may be increased.
[0034] Referring to FIG. 2 where a zirconium precursor is used as
the metal organic precursor, an inert gas is used as a purge gas
and provided into process chamber 50 for about 1 to about 30
seconds. In this example, the inert gas is included in the chamber
for about 30 seconds and the inert gas may include argon gas,
nitrogen gas, etc. By providing the purge gas into the process
chamber 50, the second portion 14 which is physisorbed on the first
portion 12 of the metal organic precursor or floated in the chamber
50 may be removed. As a result, zirconium precursor molecules 12a
remain as the first portion 12 on the substrate 10.
[0035] Instead of providing the purge gas and maintaining the
process chamber 50 in a vacuum condition for about 1 to about 30
seconds, the second portion 14 physisorbed on the first portion 12
of metal organic precursor or floated in the process chamber 50 may
be removed. Alternatively, by providing the purge gas into process
chamber 50 and maintaining the chamber in a vacuum condition, the
second portion 14 physisorbed to the first portion 12 of the metal
organic precursor or floated in the process chamber 50 may be
removed.
[0036] Referring to FIG. 3, an oxidizing agent 16 including oxygen
is provided into the chamber 50. Examples of the oxidizing agent 16
may include ozone (O3), oxygen (O2), water (H2O), plasma oxygen,
remote plasma oxygen, etc., which may be used alone or in
combination. The oxidizing agent 16 is provided into the process
chamber 50 for about 0.5 to about 5.0 seconds. By way of example,
ozone (O3) may be used as the oxidizing agent 16 and is provided
into the process chamber 50 for about 2.0 seconds. The oxidizing
agent 16 chemically reacts with the zirconium precursor molecules
12a which is the first portion 12 of a reactant chemisorbed on
substrate 10 to oxidize the zirconium precursor molecules 12a.
[0037] Referring to FIG. 4, a purge gas is provided into the
process chamber 50 where the type of purge gas and time in the
chamber 50 is substantially the same as described with reference to
FIG. 2. By providing the purge gas into the process chamber 50, the
oxidizing agent 16 that remains chemically unreacted may be
removed. In this manner, a solid material 18 including zirconium
oxide may be formed on the substrate 10.
[0038] FIG. 5 illustrates a substrate 10 on which the processes
described with reference to FIGS. 1 to 4 are performed at least
once. As a result, a thin film 20 having a multi-layer structure of
a solid material 18 may be formed on the substrate 10 where the
thin film 20 includes zirconium oxide. A thickness of the thin film
20 may be controlled according to repetition times of the
processes. The thin film 20 may include zirconium oxide or hafnium
oxide formed using a zirconium precursor or a hafnium precursor on
the substrate 10. The zirconium precursor or the hafnium precursor
has a saturated vapor pressure higher than that of a conventional
precursor so that the thin film 20 may have a relatively higher
dielectric constant and a lower leakage current. In an alternative
embodiment, instead of an ALD process in which the zirconium
precursor and the oxidizing agent are used, the thin film 20 may be
formed by a CVD process in which the zirconium precursor and the
oxidizing agent are simultaneously provided into the process
chamber 50.
[0039] When the thin film 20 including the solid material 18 is
formed on the substrate 10, the zirconium precursor in the gaseous
state and the oxidizing agent are introduced simultaneously to the
substrate 10 in the process chamber 50. The zirconium precursor and
the oxidizing agent chemically react with each other over the
substrate 10 to form zirconium oxide. The zirconium oxide is
chemisorbed onto the surface of the substrate 10 to form the solid
material 18. The zirconium oxide is successively chemisorbed onto
the solid material 18 to form the thin film 20 where the thickness
of the thin film 20 is controlled by the CVD duration.
[0040] FIG. 6 is a flow chart illustrating a method of forming a
thin film in accordance with the present invention where a
substrate is disposed in a chamber in step S110. The internal
temperature of the chamber is in the range of about 250.degree. C.
to about 450.degree. C. and preferably at 300.degree. C. A first
reactive material is provided onto the substrate in step S120 where
the first reactive material is a metal organic precursor including
a hafnium precursor and a zirconium precursor. For example, the
hafnium precursor includes tertiary-butyl-imido
bis-methyl-ethyl-amino hafnium [(t-BuN)Hf(N(CH3)(C2H5))2], and the
zirconium precursor includes tertiary-butyl-imido
bis-metyl-ethyl-amino zirconium [(t-BuN)Zr(N(CH3)(C2H5))2].
Preferably, the first reactive material is provided onto the
substrate for about 0.5 to about 3 seconds and specifically for
about 1 second by a liquid delivery system. When
tertiary-butyl-imido bis-metyl-ethyl-amino zirconium is provided
onto the substrate, a first portion of the tertiary-butyl-imido
bis-metyl-ethyl-amino zirconium may be chemisorbed onto the
substrate and a second portion of the tertiary-butyl-imido
bis-metyl-ethyl-amino zirconium may be physisorbed onto the
substrate.
[0041] In step S130, argon gas is provided onto the substrate to
perform a first purge process on the substrate. Preferably, argon
gas is provided onto the substrate for about 0.5 to about 3 seconds
and specifically for 1 second. When argon gas is provided onto the
substrate, the second portion of the tertiary-butyl-imido
bis-metyl-ethyl-amino zirconium may be removed. That is, when argon
gas is provided onto the substrate, a hydrocarbon radical contained
in the tertiary-butyl-imido bis-metyl-ethyl-amino zirconium may be
taken from the substrate. Although argon gas is provided onto the
substrate, zirconium contained in the tertiary-butyl-imido
bis-metyl-ethyl-amino zirconium may still remain chemisorbed on the
substrate. By maintaining the chamber in a vacuum condition for
about 2 to about 3 seconds, the hydrocarbon radical may be
taken-off from the substrate.
[0042] An oxidizing agent including oxygen is provided onto the
substrate in step S140. Examples of an oxidizing agent include
ozone (O3), water vapor (H2O), hydrogen peroxide (H2O2), methyl
alcohol (CH3OH), ethyl alcohol (C2H5OH), etc. which may be used
alone or in combination. In an example embodiment of the present
invention, ozone is used as the oxidizing agent. Preferably, ozone
is provided onto the substrate for about 1 to about 5 seconds and
specifically for about 3 seconds. When the oxidizing agent is
provided onto the substrate, zirconium chemisorbed on the substrate
may be oxidized. As a result, a first solid material containing
zirconium oxide is formed on the substrate.
[0043] In step S150, a second purge process using argon gas is
performed on the substrate. Preferably, argon gas is provided onto
the substrate for about 1 to about 5 seconds and specifically for
about 3 seconds. When argon gas is provided onto the substrate, an
oxidizing agent remaining in the chamber is removed. In this
manner, the first solid material including zirconium oxide is
formed on the substrate. By repeatedly providing
tertiary-butyl-imido bis-metyl-ethyl-amino zirconium, argon gas, an
oxidizing agent and argon gas, a zirconium oxide layer including
the first solid material may be formed having a predetermined
thickness.
[0044] In step S160, a second reactive material is provided onto
the first solid material formed in step S140. The second reactive
material includes an aluminum precursor. Examples of the aluminum
precursor may include tri-methyl-aluminum (TMA), tri-ethy-aluminum
(TEA), tri-isobuthyl-aluminum, etc. Preferably, the second reactive
material is provided onto the first solid material for about 1
second. By providing TEA as the second reactive material onto the
first solid material, a first portion of the TEA may be chemisorbed
onto the first solid material and a second portion of the TEA may
be physisorbed onto the first solid material.
[0045] A third purge process using argon gas is performed on the
substrate in step S170. Preferably, argon gas is provided onto the
first solid material for about 1 second as a purge gas and the
second portion of the TEA physisorbed on the first solid material
may be removed. An oxidizing agent is provided onto the first solid
material in step S180. The oxidizing agent may be substantially the
same as that described in step S140. Ozone (O3) as the oxidizing
agent may be provided onto the first solid material for about 3
seconds. When the oxidizing agent is provided onto the first solid
material, aluminum chemisorbed on the first solid material is
oxidized. As a result, a second solid material including aluminum
oxide may be formed on the first solid material.
[0046] In step S190, a fourth purge process using argon gas is
performed on the substrate. Preferably, argon gas as a purge gas is
provided onto the second solid material for about 3 seconds and the
oxidizing agent remaining in the chamber may be removed.
Accordingly, the second solid material including aluminum oxide is
formed on the first solid material. By repeatedly providing TEA,
argon gas, an oxidizing agent and argon gas, an aluminum oxide
layer including the second solid material having a predetermined
thickness may be formed. Here, a cycle is defined by the number of
processes performed that provide a precursor, argon gas, an
oxidizing agent and argon gas to form a metal oxide layer. By
controlling the number of cycles for forming the first solid
material that includes zirconium oxide using the zirconium
precursor and cycles for forming the second solid material that
includes aluminum oxide using the aluminum precursor, a composite
metal oxide layer including zirconium-aluminum oxide that has a
desired composition ratio of zirconium and aluminum may be formed
in step S200. Alternatively, instead of the zirconium precursor, a
hafnium precursor may be used. By controlling the number of cycles
for forming the first solid material that includes hafnium oxide
using the hafnium precursor and the number of cycles for forming
the second solid material that includes aluminum oxide using the
aluminum precursor, a composite metal oxide layer including
hafnium-aluminum oxide that has a desired composition ratio of
hafnium and aluminum may be formed.
Method of Manufacturing a Gate Structure
[0047] FIGS. 7-10 are cross-sectional views illustrating methods of
manufacturing a gate structure in accordance with example
embodiments of the present invention. Referring to FIG. 7, a
conventional isolation process is performed to define an active
region and a field region 102 in a substrate 100. Here, examples of
the substrate 100 may include silicon substrate,
silicon-on-insulator (SOI) substrate, etc. A gate insulation layer
104 including, for example, a metal oxide is formed on the
substrate 100 which has a relatively low EOT and sufficiently
reduces a leakage current between a gate electrode and a channel
region. In particular, the gate insulation layer 104 may include
hafnium oxide or zirconium oxide, and may be formed by an ALD
process that is substantially the same as that shown for forming
the thin film in FIGS. 1 to 5. Alternatively, the gate insulation
layer 104 may include zirconium-aluminum oxide and may be formed by
an ALD process that is substantially the same as that for forming
the thin film as shown in FIG. 6. A metal organic precursor used in
the ALD process may be represented by:
R3-N=M(N(R1)(R2))2 (2)
where R1, R2 and R3 independently represent hydrogen or an alkyl
group having one to five carbon atoms, and M represents titanium,
zirconium or hafnium. R1, R2 and R3 may, for example, independently
include a methyl group, an ethyl group, a prophyl group, and a
tertiary butyl group, etc. The metal organic precursor represented
by formula (2) may include tertiary-butyl-imido
bis-methyl-ethyl-amino hafnium [(t-BuN)Hf(N(CH3)(C2H5))2] or
tertiary-butyl-imido bis-metyl-ethyl-amino zirconium
[(t-BuN)Zr(N(CH3)(C2H5))2]. The metal organic precursor may be in a
liquid state at room temperature and may be vaporized into a
gaseous state at a temperature of about 60.degree. C. to about
95.degree. C. When the metal organic precursor is vaporized in a
canister, the vaporized metal organic precursor may have a
saturated vapor pressure of about 1 Torr to 5 Torr. Methods for
forming the gate insulation layer 104 are substantially the same as
those illustrated with reference to FIGS. 1 to 5.
[0048] In an example embodiment of the present invention, the gate
insulation layer 104 including zirconium oxide may be formed on the
substrate 100 by performing an ALD process using a hafnium
precursor or a zirconium precursor. A silicon oxide layer having a
thickness of about 5 .ANG. may also be formed on the gate
insulation layer 104. The silicon oxide layer may be formed in-situ
after the gate insulation layer 104 including zirconium oxide is
formed.
[0049] Referring to FIG. 8, a gate conductive layer 110 is formed
on the gate insulation layer 104. The gate conductive layer 110 may
be formed to have a multi-layered structure, i.e., a
poly-crystalline silicon layer 106 and a metal silicide layer such
as a tungsten silicide are sequentially stacked. A capping
insulation layer 112 including silicon oxide may be formed on the
gate conductive layer 110.
[0050] Referring to FIG. 9, the capping insulation layer 112, the
gate conductive layer 110 and the gate insulation layer 104 on the
substrate 100 are sequentially patterned by a photolithography
process. As a result, a gate structure 115 including a gate
insulation layer pattern 104a, a gate conductive pattern 110a and a
capping insulation layer pattern 112a is formed on the substrate
100. FIG. 10 illustrates a source/drain region 120 formed at an
upper portion of the substrate 100 adjacent to gate structure 115.
The source/drain region 120 may be formed before forming the gate
insulation layer 104 or after forming a spacer 114 on the gate
structure 115. The gate insulation layer pattern 104a including
hafnium oxide or zirconium oxide that has a high dielectric
constant may have a relatively low EOT which sufficiently reduces a
leakage current between a gate conductive pattern 106a and the
substrate 100. When the gate insulation layer 104 is formed using a
metal organic precursor represented by formula (2), a process time
for manufacturing the gate insulation layer 104 may be reduced so
that the gate structure 115 formed faster.
Method of Manufacturing a Capacitor
[0051] FIGS. 11 to 14 are cross-sectional views illustrating
methods of manufacturing a capacitor in accordance with example
embodiments of the present invention. FIG. 11 illustrates a
substrate 100 having an insulating interlayer 124 including a
contact hole 126 that exposes a contact plug 122. A conductive
layer 132 for a lower electrode is continuously formed on an inner
sidewall and a bottom portion of a contact hole 126 through the
insulating interlayer 124 to form an electrical connection with a
contact plug 122. When a semiconductor device such as a dynamic
random access memory (DRAM) is formed on the substrate 100, a
semiconductor structure including a gate 115 having a spacer 114, a
bit line (not shown), the contact plug 122, etc., may be formed on
the substrate 100. The conductive layer 132 may be formed using a
material such as polycrystalline silicon, titanium nitride,
tantalum nitride, tungsten nitride, ruthenium, etc. which may be
used alone or in a combination.
[0052] FIG. 12 illustrates a lower electrode 140 formed to
electrically connect to the contact plug 122. After a sacrificial
layer (not shown) is formed on the conductive layer 132, the
sacrificial layer is removed until an upper face of the conductive
layer 132 is exposed. The conductive layer 132 on the insulating
interlayer 124 is removed to form a lower electrode 140 on the
inner sidewall and bottom of the contact hole 126. The sacrificial
layer remaining in the contact hole 126 and the insulating
interlayer 124 is removed to complete the lower electrode 140. The
lower electrode 140 may have a cylindrical shape in which a width
of an upper portion is wider than that of a lower portion of the
lower electrode 140.
[0053] Referring to FIG. 13, a dielectric layer 150 is formed on
the lower electrode 140 having a relatively thin EOT and a
relatively high dielectric constant which may sufficiently reduce a
leakage current between the lower electrode 140 and an upper
electrode. In an example embodiment, the dielectric layer 150a is
formed using a thin film including a metal oxide. For example, the
thin film may include hafnium oxide or zirconium oxide and may be
formed by an ALD process that is substantially the same as that for
forming the thin film as shown in FIGS. 1 to 5. Alternatively, the
thin film may include zirconium-aluminum oxide, and may be formed
by an ALD process that is substantially the same as that for
forming the thin film as referenced in FIG. 6. A metal organic
precursor may include tertiary-butyl-imido bis-methyl-ethyl-amino
hafnium [(t-BuN)Hf(N(CH3)(C2H5))2] or tertiary-butyl-imido
bis-metyl-ethyl-amino zirconium [(t-BuN)Zr(N(CH3)(C2H5))2]. The
dielectric layer 150 including hafnium oxide may be formed on the
lower electrode 140 by an ALD process using the metal organic
precursor.
[0054] Referring to FIG. 14, after the dielectric layer 150 is
formed, it is thermally treated to remove a contaminant and restore
oxygen vacancies. The heat treatment process may include an
ultraviolet ozone (UV-O3) treatment, a plasma treatment, etc. An
upper electrode 160 may be formed on the dielectric layer 150 using
polycrystalline silicon, titanium nitride, tantalum nitride,
tungsten nitride, ruthenium, etc. which may be used alone or in
combination. Thus, a capacitor that includes the lower electrode
140, the dielectric layer 150 having hafnium oxide, and the upper
electrode 160 is formed on the substrate 100. In another
embodiment, a thin solid film including hafnium oxide that has a
high dielectric constant is formed as dielectric layer 150 having a
relatively low EOT
[0055] Saturated vapor pressures of tertiary-butyl-imido
bis-methyl-ethyl-amino hafnium [(t-BuN)Hf(N(CH3)(C2H5))2] and
tetrakis-ethyl-methyl-amino hafnium [TEMAH, Hf(NC2H5CH3)4] that are
hafnium precursors of a thin film including hafnium oxide were
respectively measured. The measurement was performed by measuring
changes in saturated vapor pressures according to different
temperatures after the hafnium precursors were contained in a 10 L
canister and the hafnium precursors were heated into a gaseous
phase. Results of measured changes in an inner pressure of the
canister at a temperature of about 20.degree. C. to about
90.degree. C. are illustrated in the graph of FIG. 15. Here, the
saturated vapor pressures of the hafnium precursors are
substantially the same as the inner pressure of the canister. As
shown in the graph, tertiary-butyl-imido bis-methyl-ethyl-amino
hafnium has a vapor pressure of about 1 Torr when the
tertiary-butyl-imido bis-methyl-ethyl-amino hafnium is heated to a
temperature of about 72.degree. C., thus, the inner pressure of the
canister is about 1 Torr. Additionally, tertiary-butyl-imido
bis-methyl-ethyl-amino hafnium has a vapor pressure of about 3 Torr
when the tertiary-butyl-imido bis-methyl-ethyl-amino hafnium is
heated to a temperature of about 90.degree. C., thus the inner
pressure of the canister is about 3 Torr. However, TEMAH (i.e., a
conventional hafnium precursor) has a vapor pressure of about 0.4
Torr when the TEMAH is heated to a temperature of about 72.degree.
C., thus the inner pressure of the canister is about 0.4 Torr.
Additionally, TEMAH has a vapor pressure of about 1 Torr when the
TEMAH is heated to a temperature of about 90.degree. C. and the
inner pressure of the canister is about 1 Torr. As a result, when
the thin film including hafnium oxide is formed,
tertiary-butyl-imido bis-methyl-ethyl-amino hafnium has a vapor
pressure that is about twice as high as that of TEMAH. Therefore,
when the thin film is formed using tertiary-butyl-imido
bis-methyl-ethyl-amino hafnium, a process time for forming the thin
film may be reduced and consequently the throughput of a
semiconductor manufacturing process may be increased.
[0056] A change in the saturated vapor pressure of
tertiary-butyl-imido bis-metyl-ethyl-amino zirconium as a zirconium
precursor was measured according to different temperatures by
substantially the same method as that illustrated with reference to
FIG. 15, the results of which are illustrated in FIG. 16. A
saturated vapor pressure of the zirconium precursor is
substantially the same as an inner pressure of a canister. As shown
in the graph, tertiary-butyl-imido bis-metyl-ethyl-amino zirconium
as a zirconium precursor has a vapor pressure of about 1 Torr when
the tertiary-butyl-imido bis-metyl-ethyl-amino zirconium is heated
to a temperature of about 72.degree. C., thus, the inner pressure
of the canister is about 1 Torr. Additionally, tertiary-butyl-imido
bis-metyl-ethyl-amino zirconium has a vapor pressure of about 2.7
Torr when the tertiary-butyl-imido bis-metyl-ethyl-amino zirconium
is heated to a temperature of about 90.degree. C., thus the inner
pressure of the canister is about 3 Torr. Therefore, when the thin
film is formed using tertiary-butyl-imido bis-metyl-ethyl-amino
zirconium, a process time for forming the thin film may be reduced
and consequently the throughput of a semiconductor manufacturing
process may be increased.
[0057] FIG. 17 is a graph illustrating results of a
thermo-gravimetric analysis (TGA) in TEMAH and tertiary-butyl-imido
bis-metyl-ethyl-amino zirconium. The TGA is an analysis that
registers a weight change in a sample according to time and
temperature while increasing a temperature of the sample at a
constant speed or isothermally maintaining the temperature of the
sample. As a result, a weight increase or a weight decrease
according to pyrolysis, sublimation, vaporization and oxidation may
be analyzed by a thermogram. While heating tertiary-butyl-imido
bis-methyl-ethyl-amino hafnium and tertiary-butyl-imido
bis-metyl-ethyl-amino zirconium that were metal organic precursors
from a room temperature to about 400.degree. C. by 5.degree.
C./min, weight loss of each precursor was measured. At a
temperature in a range of about 130.degree. C. to about 220.degree.
C., the weight loss of the each precursor abruptly occurred. That
is, tertiary-butyl-imido bis-methyl-ethyl-amino hafnium,
tertiary-butyl-imido bis-metyl-ethyl-amino zirconium and TEMAH were
vaporized from a liquid phase to a gaseous phase. Based on the
above analysis, tertiary-butyl-imido bis-methyl-ethyl-amino hafnium
and tertiary-butyl-imido bis-metyl-ethyl-amino zirconium were
confirmed as proper metal organic precursors for an ALD process
like TEMAH.
[0058] FIG. 18 is a graph illustrating a leakage current of a
capacitor having the hafnium oxide layer as a dielectric layer in
accordance with an embodiment of the present invention. A leakage
current of a cell capacitor including a hafnium oxide was measured
after a hafnium oxide layer employed in the cell capacitor was
formed by an ALD process using tertiary-butyl-imido
bis-methyl-ethyl-amino hafnium. The hafnium oxide layer had a
thickness of about 13.7 .ANG.. The cell capacitor including the
hafnium oxide layer formed using tertiary-butyl-imido
bis-methyl-ethyl-amino hafnium indicated a relatively low leakage
current of about 1.00 E-15 A/cm2 at a voltage of about 0.5V.
Additionally, the cell capacitor indicated a relatively low leakage
current of about 1.00 E-13 A/cm2 at a voltage of about 1.3V. The
cell capacitor including the hafnium oxide layer was confirmed to
have good leakage current and cell capacitance characteristics.
Thus, tertiary-butyl-imido bis-methyl-ethyl-amino hafnium precursor
was confirmed to be available in a semiconductor manufacturing
apparatus.
[0059] FIG. 19 is a graph illustrating a leakage current of a
capacitor formed using a zirconium-aluminum oxide layer in
accordance with an embodiment of the present invention. A leakage
current of a cell capacitor including a composite metal oxide layer
was measured after the composite metal oxide layer employed in the
cell capacitor was formed by an ALD process using the
tertiary-butyl-imido bis-methyl-ethyl-amino hafnium precursor and a
tri-methyl-aluminum (TMA) precursor. The composite metal oxide
layer has a stacked structure including a first zirconium oxide
(ZrO2) layer of about 70 .ANG., an aluminum oxide layer (Al2O3) of
about 4 .ANG. and a second zirconium oxide (ZrO2) layer of about 40
.ANG.. The cell capacitor including the zirconium-aluminum oxide
layer formed using a tertiary-butyl-imido bis-metyl-ethyl-amino
zirconium precursor indicated a relatively low leakage current of
about 1.00 E-17 A/cm2 at a voltage of about 0.4 V. Additionally,
the cell capacitor indicated a leakage current of about 1.00 E-16
A/cm2 at a voltage of about 2.1 V. The cell capacitor including the
zirconium-aluminum oxide layer was confirmed to have good leakage
current and cell capacitance characteristics. Thus, the
tertiary-butyl-imido bis-metyl-ethyl-amino zirconium precursor was
confirmed to have good characteristics when the
tertiary-butyl-imido bis-metyl-ethyl-amino zirconium precursor may
be used in a semiconductor manufacturing apparatus.
Conformality of a Metal Oxide Layer
TABLE-US-00001 [0060] TABLE 1 Process condition Second Chamber
Canister Carrier First Reactant Reactant Temperature Temperature
Gas (t- O3 340.degree. C. 80.degree. C. 1000 BuN)Zr(N(Me)(Et))2
sccm TEMAZ O3 320.degree. C. 80.degree. C. 1000 sccm
[0061] Zirconium oxide layers were formed on a cylindrical
structure having an aspect ratio of about 10:1 by an ALD process
according to the process conditions specified in Table 1. Step
coverage of the zirconium oxide layers was measured and the results
illustrated in FIG. 20. Step coverage is a ratio of a first
thickness of the zirconium oxide layer formed on an upper portion
of the structure with respect to a second thickness of the
zirconium oxide layer formed on a bottom of a hole contained in the
structure. FIG. 20 is a graph illustrating step coverages of
zirconium oxide layers in accordance with an embodiment of the
present invention. A zirconium oxide layer including
tertiary-butyl-imido bis-metyl-ethyl-amino zirconium precursor has
relatively high step coverage of about 87%, whereas a zirconium
oxide layer including tetra-ethyl-methyl-amid zirconium precursor
has a relatively low step coverage of about 64%. As a result,
tertiary-butyl-imido bis-metyl-ethyl-amino zirconium precursor may
be employed in a process for forming a dielectric layer of a
cylindrical capacitor.
[0062] Accordingly, when a metal organic precursor represented by
R3-N=M(N(R1)(R2))2 is used for forming a thin film including metal
oxide, the metal organic precursor may have a higher saturated
vapor pressure than those of conventional metal organic precursors
such as TEMAH or TEMAZ. Additionally, the metal organic precursor
may have a high reactivity with an oxidizing agent. Thus,
throughput and step coverage in a thin film manufacturing process
may be improved. Additionally, a thin film formed using the metal
organic precursor may have good leakage current characteristics.
Therefore, the thin film may be employed in a gate insulation layer
of a gate structure, a dielectric layer of a capacitor, etc., so
that the electrical reliability of a semiconductor device may be
improved.
[0063] Although the present invention has been described in
connection with the embodiment of the present invention illustrated
in the accompanying drawings, it is not limited thereto. It will be
apparent to those skilled in the art that various substitution,
modifications and changes may be thereto without departing from the
scope and spirit of the invention.
* * * * *