U.S. patent application number 15/827317 was filed with the patent office on 2018-06-07 for tin compound, method of synthesizing the same, tin precursor compound for atomic layer deposition, and method of forming tin-containing material film.
This patent application is currently assigned to DNF Co., Ltd.. The applicant listed for this patent is SAMSUNG ELECTRONICS CO., LTD.. Invention is credited to Youn-joung CHO, Sang-yong JEON, Myong-woon KIM, Youn-soo KIM, Kang-yong LEE, Sang-ick LEE, Jae-soon LIM, Seung-min RYU.
Application Number | 20180155372 15/827317 |
Document ID | / |
Family ID | 62240350 |
Filed Date | 2018-06-07 |
United States Patent
Application |
20180155372 |
Kind Code |
A1 |
RYU; Seung-min ; et
al. |
June 7, 2018 |
TIN COMPOUND, METHOD OF SYNTHESIZING THE SAME, TIN PRECURSOR
COMPOUND FOR ATOMIC LAYER DEPOSITION, AND METHOD OF FORMING
TIN-CONTAINING MATERIAL FILM
Abstract
A tin compound, tin precursor compound for atomic layer
deposition (ALD), a method of forming a tin-containing material
film, and a method of synthesizing a tin compound, the tin compound
being represented by Chemical Formula (I): ##STR00001## wherein
R.sup.1, R.sup.2, Q.sup.1, Q.sup.2, Q.sup.3, and Q.sup.4 are each
independently a Cl to C4 linear or branched alkyl group.
Inventors: |
RYU; Seung-min;
(Hwaseong-si, KR) ; KIM; Youn-soo; (Yongin-si,
KR) ; LIM; Jae-soon; (Seoul, KR) ; CHO;
Youn-joung; (Hwaseong-si, KR) ; KIM; Myong-woon;
(Daejeon, KR) ; LEE; Kang-yong; (Daejeon, KR)
; LEE; Sang-ick; (Daejeon, KR) ; JEON;
Sang-yong; (Sejong-si, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SAMSUNG ELECTRONICS CO., LTD. |
Suwon-si |
|
KR |
|
|
Assignee: |
DNF Co., Ltd.
Daejeon
KR
|
Family ID: |
62240350 |
Appl. No.: |
15/827317 |
Filed: |
November 30, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C23C 16/407 20130101;
C07F 7/2284 20130101; C23C 16/45553 20130101 |
International
Class: |
C07F 7/22 20060101
C07F007/22; C23C 16/455 20060101 C23C016/455 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 2, 2016 |
KR |
10-2016-0163900 |
Claims
1. A tin compound represented by Chemical Formula (I): ##STR00011##
wherein R.sup.1, R.sup.2, Q.sup.1, Q.sup.2, Q.sup.3, and Q.sup.4
are each independently a C1 to C4 linear or branched alkyl
group.
2. The tin compound as claimed in claim 1, wherein Q.sup.1,
Q.sup.2, Q.sup.3, and Q.sup.4 are each independently a methyl
group, an ethyl group, a n-propyl group, or an isopropyl group.
3. The tin compound as claimed in claim 1, wherein Q.sup.1,
Q.sup.2, Q.sup.3, and Q.sup.4 are the same and are each a methyl
group, an ethyl group, a n-propyl group, or an isopropyl group.
4. The tin compound as claimed in claim 3, wherein R.sup.1 and
R.sup.2 are each independently a methyl group, an ethyl group, a
n-propyl group, or an isopropyl group.
5. The tin compound as claimed in claim 4, wherein R.sup.1 and
R.sup.2 are the same and are each a methyl group, an ethyl group, a
n-propyl group, or an isopropyl group.
6. The tin compound as claimed in claim 1, wherein: R.sup.1 and
R.sup.2 are each a methyl group, and Q.sup.1, Q.sup.2, Q.sup.3, and
Q.sup.4 are the same and are each a methyl group or an isopropyl
group.
7. The tin compound as claimed in claim 1, wherein the tin compound
is in a liquid state at 20.degree. C.
8. A tin precursor compound for atomic layer deposition (ALD), the
tin precursor compound having a structure represented by Chemical
Formula (I): ##STR00012## wherein R.sup.1, R.sup.2, Q.sup.1,
Q.sup.2, Q.sup.3, and Q.sup.4 are each independently a C1 to C4
linear or branched alkyl group.
9. The tin precursor compound as claimed in claim 8, wherein
R.sup.1 and R.sup.2 are each independently a methyl group, an ethyl
group, a n-propyl group, or an isopropyl group.
10. The tin precursor compound as claimed in claim 9, wherein
Q.sup.1, Q.sup.2, Q.sup.3, and Q.sup.4 are the same and are each a
methyl group, an ethyl group, a n-propyl group, or an isopropyl
group.
11.-30. (canceled)
31. The tin precursor compound as claimed in claims 9, R1 and R2
are the same and are each a methyl group, an ethyl group, a
n-propyl group, or an isopropyl group.
32. The tin precursor compound as claimed in claim 8, wherein
Q.sup.1, Q.sup.2, Q.sup.3, and Q.sup.4 are each independently a
methyl group, an ethyl group, a n-propyl group, or an isopropyl
group.
33. The tin precursor compound as claimed in claim 8, wherein:
R.sup.1 and R.sup.2 are each a methyl group, and Q.sup.1, Q.sup.2,
Q.sup.3, and Q.sup.4 are the same and are each a methyl group or an
isopropyl group.
34. The tin precursor compound as claimed in claim 8, wherein the
tin compound is in a liquid state at 20.degree. C.
35. A tin precursor compound for depositing tin-containing material
film, the tin precursor compound having a structure represented by
Chemical Formula (I): <Chemical Formula (I)> ##STR00013##
wherein R.sup.1, R.sup.2, Q.sup.1, Q.sup.2, Q.sup.3, and Q.sup.4
are each independently a C1 to C4 linear or branched alkyl
group.
36. The tin precursor compound as claimed in claim 35, wherein
Q.sup.1, Q.sup.2, Q.sup.3, and Q.sup.4 are the same and are each a
methyl group, an ethyl group, a n-propyl group, or an isopropyl
group.
37. The tin precursor compound as claimed in claim 35, wherein
R.sup.1 and R.sup.2 are the same and are each a methyl group, an
ethyl group, a n-propyl group, or an isopropyl group.
38. The tin precursor compound as claimed in claim 35, wherein the
tin compound is in a liquid state at 20.degree. C.
39. The tin precursor compound as claimed in claim 35, wherein the
tin precursor compound is Sn[N(.sup.iPr).sub.2].sub.2Me.sub.2 or
Sn[N(Me).sub.2].sub.2Me.sub.2.
40. The tin precursor compound as claimed in claim 35, wherein the
tin precursor compound is synthesized by a method comprising:
obtaining SnX.sub.2R.sub.2 by reacting SnX.sub.4 with SnR.sub.4
according to Reaction Formula (I); and obtaining
Sn(NQ.sub.2).sub.2R.sub.2 by reacting SnX.sub.2R.sub.2 with
LiNQ.sub.2 according to Reaction Formula (II),
SnX.sub.4+SnR.sub.4.fwdarw.2SnX.sub.2R.sub.2 <Reaction Formula
(I)>
SnX.sub.2R.sub.2+2LiNQ.sub.2.fwdarw.Sn(NQ.sub.2).sub.2R.sub.2+2L-
iX <Reaction Formula (II)> wherein: X includes fluorine,
chlorine, bromine, or iodine, and R and Q are each independently a
C1 to C4 linear or branched alkyl group.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] Korean Patent Application No. 10-2016-0163900, filed on Dec.
2, 2016, in the Korean Intellectual Property Office, and entitled:
"Tin Compound, Method of Synthesizing the Same, Tin Precursor
Compound for ALD, and Method of Forming Tin-Containing Material
Film," is incorporated by reference herein in its entirety.
BACKGROUND
1. Field
[0002] Embodiments relate to a tin compound, a method of
synthesizing the same, a tin precursor compound for atomic layer
deposition (ALD), and a method of forming a tin-containing material
film.
2. Description of the Related Art
[0003] Due to the development of electronic technology,
down-scaling of semiconductor devices is being quickly performed in
recent years. Thus, structures of patterns constituting electronic
devices may be more complicated and finer. Along with this, a raw
material compound may be capable of forming a tin-containing thin
film to a uniform thickness on a complicated and fine 3-dimensional
structure by securing thermal stability upon the formation of the
tin-containing thin film.
SUMMARY
[0004] Embodiments are directed to a tin compound, a method of
synthesizing the same, a tin precursor compound for atomic layer
deposition (ALD), and a method of forming a tin-containing material
film.
[0005] The embodiments may be realized by providing a tin compound
represented by
[0006] Chemical Formula (I):
##STR00002##
[0007] wherein R.sup.1, R.sup.2, Q.sup.1, Q.sup.2, Q.sup.3, and
Q.sup.4 are each independently a C1 to C4 linear or branched alkyl
group.
[0008] The embodiments may be realized by providing a tin precursor
compound for atomic layer deposition (ALD), the tin precursor
compound having a structure represented by Chemical Formula
(I):
##STR00003##
[0009] wherein R.sup.1, R.sup.2, Q.sup.1, Q.sup.2, Q.sup.3, and
Q.sup.4 are each independently a C1 to C4 linear or branched alkyl
group.
[0010] The embodiments may be realized by providing a method of
forming a tin-containing material film, the method including
forming a monolayer of a tin precursor compound on a substrate in a
reaction space, the tin precursor compound having a structure
represented by Chemical Formula (I); forming a tin-containing
material film by supplying a reactant onto the monolayer; and
removing unreacted reactant from the vicinity of a surface of the
tin-containing material film by purging the unreacted reactant,
##STR00004##
[0011] wherein R.sup.1, R.sup.2, Q.sup.1, Q.sup.2, Q.sup.3, and
Q.sup.4 are each independently a C1 to C4 linear or branched alkyl
group.
[0012] The embodiments may be realized by providing a method of
synthesizing a tin compound, the method including obtaining
SnX.sub.2R.sub.2 by reacting SnX.sub.4 with SnR.sub.4 according to
Reaction Formula (I); and obtaining Sn(NQ.sub.2).sub.2R.sub.2 by
reacting SnX.sub.2R.sub.2 with LiNQ.sub.2 according to Reaction
Formula (II),
SnX.sub.4+SnR.sub.4.fwdarw.2SnX.sub.2R.sub.2 <Reaction Formula
(I)>
SnX.sub.2R.sub.2+2LiNQ.sub.2.fwdarw.Sn(NQ.sub.2).sub.2R.sub.2+2LiX
<Reaction Formula (II)>
[0013] wherein X includes fluorine, chlorine, bromine, or iodine,
and R and Q are each independently a C1 to C4 linear or branched
alkyl group.
[0014] The embodiments may be realized by providing a method of
forming a tin-containing material film, the method including
providing a substrate in a reactor; supplying a tin precursor to
the substrate to form a monolayer of the tin precursor, the tin
precursor being represented by Chemical Formula (1); supplying a
reactant onto the monolayer to form the tin-containing material
film; and purging the reactor,
##STR00005##
[0015] wherein, in Chemical Formula (I), R.sup.1 , R.sup.2,
Q.sup.1, Q.sup.2, Q.sup.3, and Q.sup.4 are each independently a C1
to C4 linear or branched alkyl group.
[0016] The embodiments may be realized by providing a semiconductor
device including the tin-containing material film prepared by the
method according to an embodiment.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Features will be apparent to those of skill in the art by
describing in detail exemplary embodiments with reference to the
attached drawings in which:
[0018] FIG. 1 illustrates a flowchart of a method of forming a
tin-containing material film, according to an embodiment;
[0019] FIG. 2 illustrates a timing diagram of the method of forming
the tin-containing material film;
[0020] FIGS. 3A and 3B illustrate cross-sectional views of stages
in a method of forming a tin-containing material film on a
substrate, according to an embodiment;
[0021] FIGS. 4A to 4H illustrate cross-sectional views of stages in
a method of fabricating an integrated circuit device, according to
embodiments;
[0022] FIGS. 5A to 5C illustrate diagrams of an integrated circuit
device according to embodiments;
[0023] FIG. 6 illustrates a graph depicting results of'H NMR
analysis of a compound obtained in Example 1;
[0024] FIG. 7 illustrates a graph depicting results of thermal
gravimetric analysis (TGA) of the compound
Sn[N(iPr).sub.2].sub.2Me.sub.2 obtained in Example 1;
[0025] FIG. 8 illustrates a graph depicting measurement results of
deposition thickness per cycle along with deposition temperature,
when deposition was performed using the compound
Sn[N(iPr).sub.2].sub.2Me.sub.2 synthesized in Example 1;
[0026] FIG. 9 illustrates a transmission electron microscope (TEM)
image of a tin oxide thin film formed in Example 2;
[0027] FIG. 10 illustrates a graph depicting results obtained by
performing X-ray diffraction (XRD) analysis on a tin oxide thin
film formed in Example 2;
[0028] FIG. 11 illustrates a graph depicting results of'H NMR
analysis of a compound obtained in Example 3;
[0029] FIG. 12 illustrates a graph depicting measurement results of
deposition thickness per cycle along with deposition temperature,
when deposition was performed by using
Sn[N(Me).sub.2].sub.2Me.sub.2, synthesized in Example 3;
[0030] FIG. 13 illustrates a graph depicting measurement results of
deposition thickness per cycle along with deposition temperature,
when deposition was performed by using Sn[N(Me).sub.2].sub.4,
synthesized in Comparative Example 1; and
[0031] FIG. 14 illustrates a graph depicting measurement results of
deposition thickness per cycle along with deposition temperature,
when deposition was performed by using Sn(Me).sub.4.
DETAILED DESCRIPTION
[0032] Tin Compound
[0033] A tin compound according to an embodiment may be represented
by Chemical Formula (I).
##STR00006##
[0034] In Chemical Formula (I), R.sup.1, R.sup.2, Q.sup.1, Q.sup.2,
Q.sup.3, and Q.sup.4 may each independently be, e.g., a C1 to C4
linear or branched alkyl group, e.g., a methyl group, an ethyl
group, a n-propyl group, or an isopropyl group.
[0035] In an implementation, R.sup.1 and R.sup.2 in the tin
compound represented by Chemical Formula (I) may be the same as or
different from each other. In an implementation, Q.sup.1, Q.sup.2,
Q.sup.3, and Q.sup.4 in the tin compound represented by Chemical
Formula (I) may be the same as or different from each other.
[0036] In an implementation, R.sup.1 and R.sup.2 may be the same,
and Q.sup.1, Q.sup.2, Q.sup.3, and Q.sup.4 may be the same. The
following compounds are examples in which R.sup.1 and R.sup.2 are
the same and Q.sup.1, Q.sup.2, Q.sup.3, and Q.sup.4 are the
same.
##STR00007##
[0037] In an implementation, R' and R.sup.2 may be different, and
Q.sup.1, Q.sup.2, Q.sup.3, and Q.sup.4 may be the same. The
following compounds are examples in which R.sup.1 and R.sup.2 are
different and Q.sup.1, Q.sup.2, Q.sup.3, and Q.sup.4 are the
same.
##STR00008##
[0038] In an implementation, R.sup.1 and R.sup.2 may be the same,
and not all Q.sup.1, Q.sup.2, Q.sup.3, and Q.sup.4 may be the same.
The following compounds are examples in which R.sup.1 and R.sup.2
are the same and not all Q.sup.1, Q.sup.2, Q.sup.3, and Q.sup.4 are
the same.
##STR00009##
[0039] In an implementation, R.sup.1 and R.sup.2 may be different,
and not all Q.sup.1, Q.sup.2, Q.sup.3, and Q.sup.4 may be the same.
The following compounds are examples in which R.sup.1 and R.sup.2
are different and not all Q.sup.1, Q.sup.2, Q.sup.3, and Q.sup.4
are the same.
##STR00010##
[0040] In an implementation, R.sup.1 and R.sup.2 may be methyl
groups, and all of Q.sup.1, Q.sup.2, Q.sup.3, and Q.sup.4 may be
isopropyl groups. In an implementation, R.sup.1 and R.sup.2 may be
methyl groups, and all of Q.sup.1, Q.sup.2, Q.sup.3, and Q.sup.4
may also be methyl groups. In an implementation, R.sup.1 and
R.sup.2 may be ethyl groups, and all of Q.sup.1, Q.sup.2, Q.sup.3,
and Q.sup.4 may be isopropyl groups.
[0041] The tin compound according to embodiments may exhibit a
substantially constant deposition rate at a temperature of about
250.degree. C. to about 350.degree. C. when applied to an atomic
layer deposition process. In an implementation, the tin compound
may exhibit excellent long-term storability due to high stability
thereof at room temperature.
[0042] The tin compound according to an embodiment may exist in a
liquid state at room temperature, and storage and handling thereof
may be facilitated. The tin compound according to an embodiment may
have good thermal stability and high reactivity, and the tin
compound may form a tin-containing material film with excellent
step coverage when applied to atomic layer deposition. The tin
compound may not include halogen elements, and the produced
tin-containing material film may not include halogen
impurities.
[0043] Method of Synthesizing Tin Compound
[0044] Hereinafter, a method of synthesizing the tin compound
represented by Chemical Formula (I) is described.
[0045] First, a tin halide and an alkyl compound of tin may be
prepared as starting materials and reacted with each other
according to Reaction Formula (I).
SnX.sub.4+SnR.sub.4.fwdarw.2SnX.sub.2R.sub.2 <Reaction Formula
(I)>
[0046] In Reaction Formula (I), X may include, e.g., fluorine (F),
chlorine (Cl), bromine (Br), or iodine (I). The four Xs bonded to
one Sn atom may be the same or different. R may be, e.g., a C1 to
C4 linear or branched alkyl group. The four Rs bonded to one Sn
atom may be the same or different.
[0047] The reaction of Reaction Formula (I) may be performed, e.g.,
at room temperature or lower. In an implementation, the reaction of
Reaction Formula (I) may be performed at a temperature of about
0.degree. C. to about 15.degree. C.
[0048] SnX.sub.2R.sub.2, which is an intermediate product produced
by the reaction of Reaction Formula (I), may be separated, followed
by obtaining the tin compound represented by Chemical Formula (I)
by reaction according to Reaction Formula (II).
SnX.sub.2R.sub.2+2LiNQ.sub.2.fwdarw.Sn(NQ.sub.2).sub.2R.sub.2+2LiX
<Reaction Formula (II)>
[0049] Q may be, e.g., a C1 to C4 linear or branched alkyl group.
The two Qs bonded to one nitrogen (N) atom may be the same or
different.
[0050] For example, the intermediate product SnX.sub.2R.sub.2 may
be brought into contact with a lithium amine compound substituted
with a C1 to C4 linear or branched alkyl group, thereby producing a
final product Sn(NQ.sub.2).sub.2R.sub.2.
[0051] For example, when a tin compound of
Sn[N(iPr).sub.2].sub.2Me.sub.2 is intended to be synthesized, an
intermediate product of Sn(CH.sub.3).sub.2Cl.sub.2 may be obtained
by reacting SnCl.sub.4, which is taken as a starting material, with
Sn(CH.sub.3).sub.4, followed by reacting the intermediate product
with lithium diisopropylamide (LiN(iPr).sub.2), thereby obtaining
the desired tin compound.
[0052] For example, when a tin compound of
Sn[N(Me).sub.2].sub.2Me.sub.2 is intended to be synthesized, an
intermediate product of Sn(CH.sub.3).sub.2Cl.sub.2 may be obtained
by reacting SnCl.sub.4, which is taken as a starting material, with
Sn(CH.sub.3).sub.4, followed by reacting the intermediate product
with lithium dimethylamide (LiN(Me).sub.2), thereby obtaining the
desired tin compound.
[0053] As used herein, the abbreviation "Me" refers to a methyl
group, and the abbreviation "iPr " refers to an isopropyl group. In
addition, as used herein, the terms "room temperature" and "ambient
temperature" refer to a temperature ranging from about 20.degree.
C. to about 28.degree. C., and may vary with the seasons.
[0054] In an implementation, the reaction of Reaction Formula (H)
may be performed, e.g., at a temperature of about 10.degree. C. to
about 50.degree. C.
[0055] Formation of Tin-Containing Material Film
[0056] The tin compound described above may be used as a tin
precursor compound for forming a tin-containing material film,
e.g., a tin metal film, a tin oxide film, a tin nitride film, a tin
oxynitride film, or a tin oxycarbonitride film. Hereinafter, a
method of forming a tin oxide film by atomic layer deposition (ALD)
will be mainly described. It will be understood by one of ordinary
skill that a tin metal film, a tin nitride film, a tin oxynitride
film, or a tin oxycarbonitride film may be formed by a similar
method.
[0057] FIG. 1 illustrates a flowchart of a method of forming a
tin-containing material film, according to an embodiment. FIG. 2
illustrates a timing diagram of the method of forming the
tin-containing material film. FIGS. 3A and 3B illustrate
cross-sectional views of stages in the method of forming the
tin-containing material film on a substrate, according to an
embodiment.
[0058] Referring to FIGS. 1, 2, and 3A, a substrate 101 may be
provided into a reaction space, and a tin precursor compound
represented by Chemical Formula (I) may be supplied onto the
substrate 101, thereby forming a monolayer 110a of the tin
precursor compound (S110).
[0059] The substrate 101 may include a semiconductor element, e.g.,
silicon (Si) or germanium (Ge), or a compound semiconductor, e.g.,
silicon carbide (SiC), gallium arsenide (GaAs), indium arsenide
(InAs), or indium phosphide (InP). In an implementation, the
substrate 101 may include a semiconductor substrate, and structures
including at least one insulating film or at least one conductive
region formed on the semiconductor substrate. The at least one
conductive region may include, e.g., an impurity-doped well, or an
impurity-doped structure.
[0060] The forming of the monolayer 110a by supplying the tin
precursor compound represented by Chemical Formula (I) onto the
substrate 101 may be performed while the substrate 101 is
maintained at a temperature of about 150.degree. C. to about
600.degree. C. or about 250.degree. C. to about 350.degree. C.
Maintaining the temperature of the substrate 101 at about
150.degree. C. or greater may help ensure that ALD reaction on the
substrate 101 sufficiently occurs. Maintaining the temperature of
the substrate 101 at about 600.degree. C. or less may help ensure
that ALD reaction sufficiently occurs by helping to prevent thermal
decomposition of the tin precursor compound.
[0061] The tin precursor compound represented by Chemical Formula
(I) may be supplied onto the substrate 101 for about 1 second to
about 100 seconds. Maintaining the supply time of the tin precursor
compound at about 1 second or greater may help ensure that the tin
precursor compound is provided at a concentration suitable for
chemisorption. Maintaining the supply time of the tin precursor
compound at about 100 seconds or less may help ensure that the tin
precursor compound is not excessively supplied, thus avoiding an
economic disadvantage.
[0062] Although being a liquid at room temperature, the tin
precursor compound represented by Chemical Formula (I) may be
vaporized at a relatively low temperature, e.g., a temperature of
about 120.degree. C. to about 180.degree. C. The vaporized tin
precursor compound represented by Chemical Formula (I) may be
chemisorbed onto a surface of the substrate 101, thereby forming a
monolayer of the tin precursor compound. In an implementation, the
tin precursor compound physisorbed onto the monolayer may further
exist and may be removed in a subsequent purge process.
[0063] Next, a purge gas may be supplied onto the surface of the
substrate 101, thereby removing the unadsorbed or physisorbed tin
precursor compound represented by Chemical Formula (I) from the
reaction space (S120). The purge gas may include, e.g., an inert
gas such as argon (Ar), helium (He), or neon (Ne), N.sub.2 gas, or
the like.
[0064] In an implementation, as illustrated in FIG. 2, the purge
gas may be supplied at the moment when the supply of the tin
precursor compound is terminated. In an implementation, the purge
gas may be used as a carrier gas of the tin precursor compound, and
the purge gas may continue to be supplied while only the supply of
the tin precursor compound is terminated, thereby achieving the
purge of the reaction space.
[0065] Referring to FIGS. 1, 2, and 3B, a reactant may be supplied
onto the surface of the substrate 101, thereby reacting the
reactant with the tin precursor compound represented by Chemical
Formula (I), the tin precursor compound for ruing the monolayer
(S130). The reactant may be supplied in a vapor phase, and may be
selected by taking into account the kind of tin-containing material
film 110 to be formed on the substrate 101.
[0066] For example, when plasma-enhanced atomic layer deposition
(PEALD) is used, plasma may be generated by applying RF power to
the reactant. The RF power may be applied to the reactant, which
flows for a pulse time period of the reactant, continuously flows
through the reaction space, and/or flows through a remote plasma
generator. Therefore, in some embodiments, the plasma may be
generated in situ, and in some other embodiments, the plasma may be
remotely generated. In an implementation, the RF power applied to
the reactant may range from about 10 W to about 2,000 W, e.g.,
about 100 W to about 1,000 W or from about 200 W to about 500 W. In
an implementation, if allowed without damaging the substrate 101,
the RF power may be greater than 2,000 W.
[0067] In an implementation. when a tin oxide film is to be formed
as the tin-containing material film 110, the reactant may include,
e.g., O.sub.2, O.sub.3, plasma O.sub.2, H.sub.2O, NO.sub.2, NO,
N.sub.2O (nitrous oxide), CO.sub.2, H.sub.2O.sub.2, HCOOH,
CH.sub.3COOH (CH.sub.3CO).sub.2O, or mixtures thereof. In an
implementation, when a tin nitride film is to be formed as the
tin-containing material film 110, the reactant may include, e.g.,
NH.sub.3, a monoalkylamine, a dialkylamine, a trialkylamine, an
organic amine compound, a hydrazine compound, or mixtures thereof.
In an implementation, the reactant may be a reductive gas, e.g.,
H.sub.2.
[0068] When the tin-containing material film 110 includes carbon, a
material capable of being used as a carbon precursor, which is a
carbon source, may include, e.g., methane (CH.sub.4), methanol
(CH.sub.3OH), carbon monoxide (CO), ethane (C.sub.2H.sub.6),
ethylene (C.sub.2H.sub.4), ethanol (C.sub.2H.sub.5OH), acetylene
(C.sub.2H.sub.2), acetone (CH.sub.3COCH.sub.3), propane
(CH.sub.3CH.sub.2CH.sub.3), propylene (C.sub.3H.sub.6), butane
(C.sub.4H.sub.10), pentane (CH.sub.3(CH.sub.2).sub.3CH.sub.3),
pentene (C.sub.5H.sub.10), cyclopentadiene (C.sub.5H.sub.6), hexane
(C.sub.6H.sub.14), cyclohexane (C.sub.6H.sub.12), benzene
(C.sub.6H.sub.6), toluene (C.sub.7H.sub.8), or xylene
(C.sub.6H.sub.4(CH.sub.3).sub.2).
[0069] Next, the purge gas may be supplied onto the surface of the
substrate 101, thereby removing the unreacted reactant from the
reaction space (S140). Here, by-products, which are obtained by
reaction between the reactant and the tin precursor compound
forming the monolayer, or the like, may also be simultaneously
removed. The purge gas may include, e.g., an inert gas such as
argon (Ar), helium (He), or neon (Ne), N.sub.2 gas, or the
like.
[0070] The operations described above may constitute one cycle, and
may be repeated so that the tin-containing material film 110 having
a desired thickness is obtained.
[0071] To apply the tin precursor compound represented by Chemical
Formula (I) to ALD, conditions in the reactor should be such that a
temperature range allowing ALD are present. An increase rate of the
thickness of the tin-containing material film per cycle may be
constant in the temperature range allowing ALD. As such, the
temperature range allowing ALD is referred to as an ALD window, and
the ALD window may depend upon the tin precursor compound. If the
ALD window were to be too narrow, it could be difficult to perform
ALD due to a narrow process margin of an ALD process. In addition,
some tin compounds, e.g., those not represented by Chemical Formula
(I), may not have the temperature range in which the increase rate
of the thickness of the tin-containing material film per cycle is
constant, e.g., may not have the ALD window.
[0072] At a deposition temperature out of the ALD window, the
increase rate of the thickness of the tin-containing material film
per cycle may somewhat vary depending upon the deposition
temperature, despite use of the tin precursor compound represented
by Chemical Formula (I). For example, a deposition mechanism other
than ALD may partially occur in deposition of the tin-containing
material film. For example, such a temperature-dependent change of
the increase rate of the thickness of the tin-containing material
film per cycle may result from partial or overwhelming intervention
of a mechanism of chemical vapor deposition.
[0073] Formation of Tin-Containing Material Film by CVD
[0074] Although an example in which the tin-containing material
film is formed by ALD has been described above, the tin precursor
compound represented by Chemical Formula (I) may also be used as a
precursor material for chemical vapor deposition (CVD).
[0075] For example, the tin-containing material film may be formed
on a substrate by using the tin precursor compound represented by
Chemical Formula (I). The tin precursor compound represented by
Chemical Formula (I) may be in a liquid phase at room temperature
and stable, and may be vaporized at a temperature of about
120.degree. C. to about 180.degree. C. and thus may undergo CVD
even at a relatively low temperature.
[0076] A thin film forming raw material for forming the
tin-containing material film may vary depending upon a thin film
intended to be formed. In some embodiments, when a thin film
including only tin (Sn) is fabricated, the thin film forming raw
material may not include metal compounds and semimetal compounds
other than the tin precursor compound according to an embodiment.
In an implementation, when a thin film including two or more metals
and/or semimetals is fabricated, the thin film forming raw material
may include a compound (referred to as the term "another precursor"
hereinafter) containing a desired metal or semimetal, in addition
to the tin precursor compound according to an embodiment. In an
implementation, the thin film forming raw material may include an
organic solvent or a nucleophilic reagent in addition to the tin
precursor compound according to an embodiment.
[0077] When the thin film forming raw material is a raw material
for use in a CVD process, the composition of the thin film forming
raw material may be appropriately selected depending upon a
specific method of the CVD process, a raw material transfer method,
or the like.
[0078] The raw material transfer method may include a gas transfer
method and a liquid transfer method. In the gas transfer method, a
raw material for CVD may be made to be in a vapor state by
vaporizing the raw material through heating or decompression in a
container (which may be referred to as the term "raw material
container" hereinafter) in which the raw material is stored, and
the vapor-state raw material and a carrier gas such as argon,
nitrogen, helium, or the like, which is used as needed, may be
simultaneously supplied into a chamber (which may be referred to as
the term "deposition reactor" hereinafter), in which the substrate
is placed, for about 1 second to about 600 seconds. In the liquid
transfer method, the raw material for CVD may be transferred in a
liquid or solution state to a vaporizer and made into vapor by
vaporizing the raw material through heating and/or decompression in
the vaporizer, followed by introducing the vapor into the chamber.
In the gas transfer method, the tin precursor compound itself
represented by Chemical Formula (I) may be used as a CVD raw
material. The CVD raw material may further include another
precursor, a nucleophilic reagent, or the like. In an
implementation, a temperature inside the chamber may be maintained
at about 100.degree. C. to about 1,000.degree. C. In an
implementation, a pressure inside the chamber may be maintained at
about 10 Pa to about 1 atmosphere (atm).
[0079] In an implementation, in the method of forming the
tin-containing material film, a multi-component CVD process may be
used to form the tin-containing material film. In the
multi-component CVD process, a method of supplying raw material
compounds, which are to be used for the CVD process, independently
for each component (hereinafter, the method may be referred to as
the term "single source method"), or a method of supplying a
multi-component raw material by vaporizing a raw material mixture
in which multiple components are mixed in a desired composition
ratio (hereinafter, the method may be referred to as the term
"cocktail source method") may be used. When the cocktail source
method is used, a first mixture including the tin precursor
compound according to an embodiment, a first mixed solution in
which the first mixture is dissolved in an organic solvent, a
second mixture including the tin precursor compound according to an
embodiment and another precursor, or a second mixed solution in
which the second mixture is dissolved in an organic solvent may be
used as a thin film forming raw material compound in the CVD
process. Each of the first and second mixtures and the first and
second mixed solutions may further include a nucleophilic
reagent.
[0080] The organic solvent for obtaining the first or second mixed
solution may include, e.g., acetate esters such as ethyl acetate
and methoxyethyl acetate; ethers such as tetrahydrofuran,
tetrahydropyran, ethylene glycol dimethyl ether, diethylene glycol
dimethyl ether, triethylene glycol dimethyl ether. dibutyl ether,
and dioxane; ketones such as methyl butyl ketone, methyl isobutyl
ketone, ethyl butyl ketone, dipropyl ketone, diisobutyl ketone,
methyl amyl ketone, cyclohexanone, and methylcyclohexanone;
hydrocarbons such as hexane, cyclohexane, methyl cyclohexane,
dimethylcyclohexane, ethylcyclohexane, heptane, octane, toluene,
and xylene; cyano group-containing hydrocarbons such as
1-cyanopropane, 1-cyanobutane, 1-cyanohexane, cyanocyclohexane,
cyanobenzene, 1,3-dicyanopropane, 1,4-dicyanobutane,
1,6-dicyanohexane, 1,4-dicyanocyclohexane, and 1,4-dicyanobenzene;
pyridine; lutidine; or the like. The organic solvents set forth
above as examples may be used alone or in combination, by taking
into account solubility of a solute, temperatures for use thereof
and melting points thereof, flash points thereof, or the like. The
tin precursor compound according to an embodiment and the another
precursor may be present in a total concentration of about 0.01
mol/L to about 2.0 mol/L, e.g., about 0.05 mol/L to about 1.0
mol/L, in the organic solvent. Here, the total concentration of the
tin precursor compound and the another precursor refers to an
amount of the tin precursor compound when the thin film forming raw
material does not include metal compounds and semimetal compounds
other than the tin precursor compound, and refers to a sum of
amounts of the tin precursor compound and the another precursor
when the thin film forming raw material further includes, in
addition to the tin precursor compound, a compound containing other
metals than tin or a compound containing semimetals.
[0081] In an implementation, examples of the other precursor in the
method of forming the thin film may include at least one Si or
metal compound selected from among compounds having hydride,
hydroxide, halide, azide, alkyl, alkenyl, cycloalkyl, allyl,
alkynyl, amino, dialkylaminoalkyl, monoalkylamino, dialkylamino,
diamino, di(silyl-alkyl)amino, di(alkyl-silyl)amino, disilylamino,
alkoxy, alkoxyalkyl, hydrazide, phosphide, nitrile,
dialkylaminoalkoxy, alkoxyalkyldialkylamino, siloxy, diketonate,
cyclopentadienyl, silyl, pyrazolate, guanidinate,
phosphoguanidinate, amidinate, ketoiminate, diketoiminate,
carbonyl. and phosphoamidinate groups as ligands.
[0082] In an implementation, the metal included in the other
precursor may include, e.g., magnesium (Mg), calcium (Ca),
strontium (Sr), barium (Ba), radium (Ra), scandium (Sc), yttrium
(Y), titanium (Ti), zirconium (Zr), hafnium (Hf), vanadium (V),
niobium (Nb), chromium (Cr), molybdenum (Mo), tungsten (W),
manganese (Mn), iron (Fe), osmium (Os), cobalt (Co), rhodium (Rh),
iridium (Ir), nickel (Ni), palladium (Pd), platinum (Pt), copper
(Cu), silver (Ag), gold (Au), zinc (Zn), cadmium (Cd), aluminum
(Al), gallium (Ga), indium (In), germanium (Ge), tantalum (Ta),
lead (Pb), antimony (Sb), bismuth (Bi), lanthanum (La), cerium
(Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium
(Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium
(Dy), holmium (Ho), erbium (Er), thulium (Tm) , ytterbium (Yb), or
the like.
[0083] In an implementation, when an alcohol compound is used as an
organic ligand, the other precursor may be prepared by reacting an
inorganic salt of the metal set forth above or a hydrate thereof
with an alkali metal alkoxide of the alcohol compound. In an
implementation, examples of the inorganic salt of the metal or the
hydrate thereof may include halides, nitrates, and the like of the
metal, and examples of the alkali metal alkoxide may include sodium
alkoxides, lithium alkoxides, potassium alkoxides, and the
like.
[0084] In the single source method, as the other precursor, a
compound exhibiting thermal and/or oxidative decomposition
behaviors that are similar to those of the tin precursor compound
according to an embodiment may be used. In addition, in the
cocktail source method, it is suitable to use, as the other
precursor, a compound that exhibits thermal and/or oxidative
decomposition behaviors similar to those of the tin precursor
compound and is not altered by chemical reactions or the like upon
mixing thereof.
[0085] Application of Tin-Containing Material Film
[0086] The tin-containing material film fabricated by the method of
forming the thin film, may be used for various purposes. For
example, the tin-containing material film may be used for a gate of
a transistor, a conductive barrier film included in a metal wire
such as a copper wire, a tunnel barrier film of a gate dielectric
film included in a 3-dimentional charge trap flash (CTF) cell, a
barrier metal film for liquid crystals, a member for thin film
solar cells, a member for semiconductor equipment, a
nano-structure, or the like.
[0087] FIGS. 4A to 4H illustrate cross-sectional views of stages in
a method of fabricating an integrated circuit device, according to
embodiments. A method of fabricating a memory cell array of an
integrated circuit device 200 (see FIG. 4H) constituting a vertical
non-volatile memory device will be described with reference to
FIGS. 4A to 4H.
[0088] Referring to FIG. 4A, an etch stop insulating film 222 may
be formed on a substrate 210, and a plurality of sacrificial layers
P224 and a plurality of insulating layers 226 may be alternately
stacked on the etch stop insulating film 222, layer by layer. A
thickness of the uppermost insulating layer 226 may be greater than
a thickness of another insulating layer 226.
[0089] The substrate 210 may be the same as the substrate 101
described above, and repeated descriptions thereof may be
omitted.
[0090] The etch stop insulating film 222 and the plurality of
insulating layers 226 may include an insulating material, e.g.,
silicon oxide. The plurality of sacrificial layers P224 may include
a material having etch selectivity that is different from those of
the etch stop insulating film 222 and the plurality of insulating
layers 226. For example, the plurality of sacrificial layers P224
may include a silicon nitride film, a silicon oxynitride film, a
polysilicon film, or a polysilicon germanium film.
[0091] Referring to FIG. 4B, a plurality of channel holes 230 may
be formed through the plurality of insulating layers 226, the
plurality of sacrificial layers P224, and the etch stop insulating
film 222 and may expose the substrate 210.
[0092] Referring to FIG. 4C, a charge storage film 232 and a tunnel
dielectric film 234 may be formed in this stated order and cover an
inner wall of each of the plurality of channel holes 230, and a
channel region 240 may be formed and covers the tunnel dielectric
film 234.
[0093] For example, the charge storage film 232 and the tunnel
dielectric film 234 may be formed in the plurality of channel holes
230. Next, a channel region-forming semiconductor film may be
formed on the tunnel dielectric film 234 in the plurality of
channel holes 230, followed by anisotropically etching the
semiconductor film, thereby exposing the substrate 210 in each of
the plurality of channel holes 230. The semiconductor film may
remain as the spacer-shaped channel region 240, which covers a
sidewall of the tunnel dielectric film 234 in each of the plurality
of channel holes 230. In an implementation, the charge storage film
232 may include a silicon nitride film. The tunnel dielectric film
234 may include a silicon oxide film.
[0094] The channel region 240 may not completely fill an inside of
each channel hole 230. An insulating film 242 may fill a space
remaining above the channel region 240 in each channel hole
230.
[0095] Next, the charge storage film 232, the tunnel dielectric
film 234, the channel region 240, and the insulating film 242 in
the plurality of channel holes 230 may be partially removed,
whereby an upper space may be formed in each of the plurality of
channel holes 230, and a conductive pattern 250 may fill the upper
space. The conductive pattern 250 may include doped polysilicon or
a metal. The conductive pattern 250 may be used as a drain
region.
[0096] Referring to FIG. 4D, a plurality of openings 260 may be
formed through the plurality of insulating layers 226, the
plurality of sacrificial layers P224, and the etch stop insulating
film 222 and may expose the substrate 210. Each of the plurality of
openings 260 may be a word line cut region.
[0097] Referring to FIG. 4E, the plurality of sacrificial layers
P224 may be removed from the plurality of openings 260, thereby
forming a plurality of gate spaces GS each between two of the
plurality of insulating layers 226. The charge storage film 232 may
be exposed by the plurality of gate spaces GS.
[0098] Referring to FIG. 4F, a blocking insulating film 236 may be
formed and may cover inner walls of the plurality of gate spaces
GS.
[0099] The blocking insulating film 236 may include a tin oxide
film. To form the blocking insulating film 236, the method of
forming the thin film may be used, the method having been described
with reference to FIGS. 1 to 3B. In an implementation, to form the
blocking insulating film 236, an ALD process may be used. As a Sn
source, the tin precursor compound according to an embodiment,
e.g., the tin precursor compound represented by Chemical Formula
(I), may be supplied through the plurality of openings 260. The ALD
process may be performed at a first temperature selected from a
range of about 250.degree. C. to about 350.degree. C. After the
formation of the tin oxide film, the tin oxide film may be
densified by annealing the tin oxide film at a second temperature
that is higher than the first temperature. The second temperature
may be selected from a range of about 400.degree. C. to about
1,150.degree. C.
[0100] Referring to FIG. 4G, a conductive layer for gate electrodes
may be formed and may fill spaces surrounded by the blocking
insulating film 236 and remaining in the plurality of gate spaces
GS, followed by partially removing the blocking insulating film 236
and the conductive layer for gate electrodes so that a sidewall of
each of the plurality of insulating layers 226 in the plurality of
openings 260 is exposed, whereby the blocking insulating film 236
and a gate electrode 264 remain in the plurality of openings
260.
[0101] In an implementation, the gate electrode 264 may include a
first conductive barrier film contacting the blocking insulating
film 236, and a first conductive film on the first conductive
barrier film. The first conductive barrier film may include a
conductive metal nitride, e.g., TiN or TaN. The first conductive
film may include conductive polysilicon, a metal, a metal silicide,
or combinations thereof.
[0102] The blocking insulating film 236 may include a tin oxide
film free from undesired foreign substances such as halogen
materials or carbon residue. As described with reference to FIG.
4F, the tin oxide film may be annealed and thus densified, thereby
preventing, e.g., damage of a constitution material of the gate
electrode 264 filling the gate spaces GS since an excess of the
blocking insulating film 236 may be consumed by an etching solution
or the blocking insulating film 236 at entrance sides of the
plurality of gate spaces GS undergoes undesired removal by an
etching solution, while the blocking insulating film 236 and the
conductive layer for gate electrodes are partially removed in the
process of FIG. 4G so that the sidewall of each of the plurality of
insulating layers 226 may be exposed.
[0103] As described above, after the blocking insulating film 236
and the gate electrode 264 are formed in the plurality of gate
spaces GS, the substrate 210 may be exposed by the plurality of
openings 260. A plurality of common source regions 268 may be
formed in the substrate 210 by implanting impurities into the
substrate 210 exposed by the plurality of openings 260.
[0104] Referring to FIG. 4H, an insulating spacer 272 may be formed
on an inner sidewall of each of the plurality of openings 260, and
a conductive plug 274 may fill an inner space of each of the
plurality of openings 260.
[0105] In an implementation, the insulating spacer 272 may include
a silicon oxide film, a silicon nitride film, or combinations
thereof The conductive plug 274 may include a second conductive
barrier film contacting the insulating spacer 272, and a second
conductive film filling a space surrounded by the second conductive
barrier film in each of the plurality of openings 260. The second
conductive barrier film may include a conductive metal nitride,
e.g., TiN or TaN. The second conductive film may include a metal,
e.g., tungsten.
[0106] A plurality of first contacts 282 may be respectively formed
on a plurality of conductive plugs 274, and a plurality of first
conductive layers 284 may be respectively formed on the plurality
of first contacts 282. Each of the plurality of first contacts 282
and the plurality of first conductive layers 284 may include a
metal, a metal nitride, or combinations thereof.
[0107] A plurality of second contacts 292 and a plurality of bit
lines 294 may be formed on a plurality of conductive patterns 250.
Each of the plurality of second contacts 292 and the plurality of
bit lines 294 may include a metal, a metal nitride, or combinations
thereof.
[0108] According to the method of fabricating the integrated
circuit device 200, which has been described with reference to
FIGS. 4A to 4H, the tin precursor compound according to an
embodiment may be used in the ALD process for forming the blocking
insulating film 236 including tin oxide, thereby securing
properties required as a raw material compound upon the ALD
process, e.g., high thermal stability, low melting point, high
vapor pressure, transportability in a liquid state, ease of
vaporization, and the like. Therefore, the blocking insulating film
236 may be easily formed by using the tin precursor compound
according to an embodiment. In addition, the blocking insulating
film 236 having uniform step coverage along the depths of holes
having relatively high aspect ratios may be obtained.
[0109] FIGS. 5A to 5C illustrate an integrated circuit device
according to embodiments. FIG. 5A illustrates perspective views of
main components of an integrated circuit device 500 including a
first transistor TR51 and a second transistor TR52, which have
FinFET structures, FIG. 5B illustrates cross-sectional views
respectively taken along lines B1-B1' and B2-B2' of FIG. 5A, and
FIG. 5C illustrates cross-sectional views respectively taken along
lines C1-C1' and C2-C2' of FIG. 5A.
[0110] The integrated circuit device 500 may include a first
fin-type active region F1 and a second fin-type active region F2,
which respectively protrude from a first region I and a second
region II of a substrate 510 in a direction (Z direction)
perpendicular to a main surface of the substrate 510.
[0111] The first region I and the second region II refer to
different regions of the substrate 510 and may be regions
performing different functions on the substrate 510. The first
transistor TR51 and the second transistor TR52, which require
different threshold voltages, may be respectively formed in the
first region I and the second region II. In an implementation, the
first region I may be a PMOS transistor region, and the second
region II may be an NMOS transistor region.
[0112] The first fin-type active region F1 and the second fin-type
active region F2 may extend along one direction (Y direction in
FIGS. 5A to 5C). In the first region I and the second region II, a
first device isolation film 512 and a second device isolation film
514 may be formed on the substrate 510 and may respectively cover
lower sidewalls of the first fin-type active region F1 and the
second fin-type active region F2. The first fin-type active region
F1 may protrude in a fin shape upwards from the first device
isolation film 512, and the second fin-type active region F2 may
protrude in a fin shape upwards from the second device isolation
film 514.
[0113] The first fin-type active region F1 and the second fin-type
active region F2 may respectively have a first channel region CHI
and a second channel region CH2 on upper portions thereof. A P-type
channel may be formed in the first channel region CH1, and an
N-type channel may be formed in the second channel region CH2.
[0114] In an implementation, each of the first fin-type active
region F1 and the second fin-type active region F2 may include a
single material. For example, the first fin-type active region F1
and the second fin-type active region F2, which respectively
include the first channel region CH1 and the second channel region
CH2, may include Si in all regions thereof. In an implementation,
the first fin-type active region F1 and the second fin-type active
region F2 may respectively include a region including Ge and a
region including Si.
[0115] Each of the first and second device isolation films 512 and
514 may include a silicon-containing insulating film, e.g., a
silicon oxide film, a silicon nitride film, a silicon oxynitride
film, a silicon carbonitride film, or the like, polysilicon, or
combinations thereof.
[0116] In the first region I, a first gate structure GA may extend
on the first fin-type active region F1 in a direction (X direction
in FIGS. 5A to 5C) intersecting the extension direction of the
first fin-type active region F1, the first gate structure GA
including a first interfacial film 522A, a first high-K dielectric
film 524A, a first etch stop layer 526A, a first work function
adjusting layer 528, a second work function adjusting layer 529,
and a first gap-fill gate film 530A. which are stacked in this
stated order. The first transistor TR51 may be formed at a point at
which the first fin-type active region F1 intersects the first gate
structure GA.
[0117] In the second region II, a second gate structure GB extends
on the second fin-type active region F2 in the direction (X
direction in FIGS. 5A to 5C) intersecting the extension direction
of the second fin-type active region F2, the second gate structure
GB including a second interfacial film 522B, a second high-K
dielectric film 524B, a second etch stop layer 526B, the second
work function adjusting layer 529, and a second gap-fill gate film
530B, which are stacked in this stated order. The second transistor
TR52 may be formed at a point at which the second fin-type active
region F2 intersects the second gate structure GB.
[0118] The first interfacial film 522A and the second interfacial
film 522B may include films obtained by oxidizing surfaces of the
first fin-type active region F1 and the second fin-type active
region F2, respectively. In an implementation, each of the first
interfacial film 522A and the second interfacial film 522B may
include a low-K dielectric material layer having a dielectric
constant of about 9 or less, e.g., a silicon oxide film, a silicon
oxynitride film, or combinations thereof. In an implementation,
each of the first interfacial film 522A and the second interfacial
film 522B may have a thickness of, e.g., about 5 .ANG. to about 20
.ANG.. In an implementation, the first interfacial film 522A and
the second interfacial film 522B may be omitted.
[0119] Each of the first high-K dielectric film 524A and the second
high-K dielectric film 524B may include a metal oxide having a
higher dielectric constant than a silicon oxide film. For example,
each of the first high-K dielectric film 524A and the second high-K
dielectric film 524B may have a dielectric constant of about 10 to
about 25. In an implementation, each of the first high-K dielectric
film 524A and the second high-K dielectric film 524B may include.
e.g., hafnium oxide, hafnium oxynitride, hafnium silicon oxide,
lanthanum oxide. lanthanum aluminum oxide, zirconium oxide,
zirconium silicon oxide, tin oxide, tin oxynitride, tin
oxycarbonitride, tantalum oxide, titanium oxide, barium strontium
titanium oxide, barium titanium oxide, strontium titanium oxide,
yttrium oxide, aluminum oxide, lead scandium tantalum oxide, lead
zinc niobate, or combinations thereof.
[0120] The first high-K dielectric film 524A and the second high-K
dielectric film 524B may be formed by an ALD or CVD process. In an
implementation, each of the first high-K dielectric film 524A and
the second high-K dielectric film 524B may have a thickness of,
e.g., about 10 .ANG. to about 40 .ANG..
[0121] When each of the first high-K dielectric film 524A and the
second high-K dielectric film 524B includes a Sn-containing film,
the first high-K dielectric film 524A and the second high-K
dielectric film 524B may be formed by using a thin film forming raw
material, which includes the tin precursor compound represented by
Chemical Formula (I) as set forth above.
[0122] Each of the first etch stop layer 526A and the second etch
stop layer 526B may include a SnN film. The first etch stop layer
526A and the second etch stop layer 526B may be formed by a CVD or
ALD process by using a thin film forming raw material, which
includes the tin precursor compound represented by Chemical Formula
(I) as set forth above, and using a nitrogen atom-containing
reactive gas, for example, NH.sub.3 gas.
[0123] The first work function adjusting layer 528 may be for
adjusting a work function of the P-type transistor, and may
include, e.g., TiN.
[0124] The second work function adjusting layer 529 may be for
adjusting a work function of the N-type transistor. and may
include, e.g., TiAl, TiAlC, TiAlN, TaC, TiC, HfSi, or combinations
thereof.
[0125] Each of the first gap-fill gate film 530A and the second
gap-fill gate film 530B may include. e.g., tungsten (W).
[0126] In an implementation, a conductive barrier film may be
interposed between the second work function adjusting layer 529 and
the first gap-fill gate film 530A, and/or between the second work
function adjusting layer 529 and the second gap-fill gate film
530B. In an implementation, the conductive barrier film may include
a metal nitride, e.g., TiN, TaN, SnN, or combinations thereof.
[0127] A pair of first source/drain regions 562 may be formed in
the first fin-type active region F1 at both sides of the first gate
structure GA. A pair of second source/drain regions 564 may be
formed in the second fin-type active region F2 at both sides of the
second gate structure GB.
[0128] The pairs of first and second source/drain regions 562 and
564 may respectively include semiconductor layers epitaxially grown
on the first and second fin-type active regions F1 and F2. Each of
the pairs of first and second source/drain regions 562 and 564 may
include an embedded SiGe structure including a plurality of
epitaxially grown SiGe layers, an epitaxially grown Si layer, or an
epitaxially grown SiC layer.
[0129] In an implementation, as illustrated in FIGS. 5A and 5C, the
pairs of first and second source/drain regions 562 and 564 may have
a specific shape. In an implementation, the pairs of first and
second source/drain regions 562 and 564 may have various sectional
shapes.
[0130] Each of the first and second transistors TR51 and TR52 may
include a 3-dimensional structured MOS transistor in which a
channel is formed on an upper surface and both side surfaces of
each of the first and second fin-type active regions F1 and F2. The
MOS transistor may constitute an NMOS transistor or a PMOS
transistor.
[0131] In the first region I and the second region II, an
insulating spacer 572 may be formed on both sides of each of the
first and second gate structures GA and GB. As shown in FIG. 5C, an
insulating film 578 covering the insulating spacer 572 may be
formed at an opposite side to each of the first and second gate
structures GA and GB, with the insulating spacer 572 being between
each of the first and second gate structures GA and GB and the
insulating film 578. In an implementation, the insulating spacer
572 may include a silicon nitride film and the insulating film 578
may include a silicon oxide film.
[0132] The following Examples and Comparative Examples are provided
in order to highlight characteristics of one or more embodiments,
but it will be understood that the Examples and Comparative
Examples are not to be construed as limiting the scope of the
embodiments, nor are the Comparative Examples to be construed as
being outside the scope of the embodiments. Further, it will be
understood that the embodiments are not limited to the particular
details described in the Examples and Comparative Examples.
EXAMPLE 1
[0133] Synthesis of Compound Sn[N(iPr).sub.2].sub.2Me.sub.2
[0134] 100 g (0.35 mol) of SnCl.sub.4 and 300 ml of n-hexane were
introduced into a 1,000 ml flask and mixed. 81.4 g (0.455 mol) of
Sn(Me).sub.4 was slowly added into the flask in an ice bath. The
components were stirred for about 2 hours, thereby completing
synthesis of SnMe.sub.2Cl.sub.2.
[0135] Next, 204 g (1.91 mol) of lithium diisopropylamide (LDA) was
diluted with ethyl ether and then slowly added into the flask. The
reaction was completed by stirring the components for 5 hours,
followed by removing a solvent and by-products at reduced
pressure.
[0136] Next, the resultant was purified at a temperature of
80.degree. C. and a pressure of 0.6 Torr. thereby obtaining 120 g
of a compound Sn[N(iPr).sub.2].sub.2Me.sub.2 (yield: 77%).
[0137] The obtained compound underwent .sup.1H NMR analysis.
Results are shown in FIG. 6.
[0138] (Analysis)
[0139] .sup.1H NMR(C6D6): .delta. 3.42(st,4H,), 1.12(d,24H),
0.38(s,6H)
EVALUATION EXAMPLE 1
[0140] Evaluation of Properties of Compound
Sn[N(iPr).sub.2].sub.2Me.sub.2
[0141] FIG. 7 illustrates a graph depicting results of thermal
gravimetric analysis (TGA) of the compound
Sn[N(iPr).sub.2].sub.2Me.sub.2 obtained in Example 1. 10 mg of the
compound Sn[N(iPr).sub.2].sub.2Me.sub.2 was analyzed at a heating
rate of 10.degree. C./min under an argon atmosphere.
[0142] FIG. 7 shows weight loss percentage along with temperature.
As may be seen in FIG. 7, the Sn[N(iPr).sub.2].sub.2Me.sub.2
exhibited quick vaporization and was vaporized to a degree of 99%
or more at about 190.degree. C. without residue due to thermal
decomposition.
EXAMPLE 2
[0143] A tin oxide thin film was fabricated on a silicon substrate
by atomic layer deposition (ALD).
[0144] The silicon substrate was loaded into a reaction chamber and
maintained at a temperature of 200.degree. C. The compound
Sn[N(iPr).sub.2].sub.2Me.sub.2 synthesized in Example 1 filled a
stainless steel bubbler container and was maintained at a
temperature of 74.degree. C. Next, the tin precursor compound was
vaporized in the bubbler container and supplied onto a surface of
the silicon substrate using argon gas as a carrier gas (25 seem),
thereby chemisorbing the compound Sn[N(iPr).sub.2].sub.2Me.sub.2
onto the silicon substrate. Next, unadsorbed
Sn[N(iPr).sub.2].sub.2Me.sub.2 was purged with argon gas (4,000
sccm) for 15 seconds and thereby removed from the reaction
chamber.
[0145] Next, ozone gas having a concentration of 220 g/m.sup.3 was
supplied into the reaction chamber at a flow rate of 300 sccm for 7
seconds. thereby forming the tin oxide thin film. Finally,
by-products and unreacted materials were purged with argon gas
(4,000 sccm) for 10 seconds and thereby removed from the reaction
chamber.
[0146] When the processes set forth above were defined as 1 cycle,
a tin oxide thin film was formed by repeating 100 cycles and
underwent thickness measurement.
[0147] In addition, deposition for 100 cycles was performed at each
temperature while changing the temperature inside the reaction
chamber, and a deposition thickness per cycle at each temperature
was measured. Results are shown in FIG. 8.
[0148] As shown in FIG. 8, it may be seen that the deposition
thickness per cycle changed along with the deposition temperature
varying from 200.degree. C. to 270.degree. C. Therefore, it may be
seen that a deposition mechanism other than ALD could contributed
to the formation of the thin film at 200.degree. C. to 270.degree.
C. Likewise, it may be seen that the deposition thickness per cycle
changed along with the deposition temperature varying from
350.degree. C. to 380.degree. C. Therefore, it may be seen that a
deposition mechanism other than ALD, e.g., chemical vapor
deposition, may have contributed to the formation of the thin film
at 350.degree. C. to 380.degree. C.
[0149] It may be seen that the deposition thickness per cycle was
constant even when the deposition temperature varied in a range of
270.degree. C. to 350.degree. C. For example, in a temperature
range of 270.degree. C. to 350.degree. C., the tin oxide thin film
was formed by a mechanism of ALD.
[0150] To analyze a crystal structure of the tin oxide thin film
formed as above, transmission electron microscope (TEM) analysis
and X-ray diffraction (XRD) analysis were performed on the tin
oxide thin film, and an image obtained by analysis and a graph of
analysis results are respectively shown in FIGS. 9 and 10.
[0151] Referring to FIG. 9, it may be seen that the tin oxide
(SnO.sub.2) thin film was formed on the silicon substrate and a
glue layer for TEM analysis was formed on the tin oxide thin film.
As shown in FIG. 9, it may be seen that the tin oxide thin film was
formed to a relatively uniform thickness on the silicon
substrate.
[0152] The composition of the tin oxide thin film was analyzed by
X-ray photoelectron spectroscopy (XPS), and results thereof are
shown in Table 1. Referring to Table 1, it may be seen that the
deposited thin film included about 33.3 atom% of tin and about 66.7
atom% of oxygen based on a silicon substrate temperature of
300.degree. C., and a stoichiometric ratio of tin to oxygen was
about 1:2. Thus, the thin film had a composition of SnO.sub.2. In
addition, nitrogen, carbon, and halogen elements, which were
impurities, were not detected, and it may be seen that the pure tin
oxide thin film free from impurities was formed.
TABLE-US-00001 TABLE 1 Temperature Atom % (XPS) (.degree. C.) Sn 3
d O 1 s N 1 s C 1 s O/Sn 270 32.6 67.4 0.0 0.0 2.1 300 33.3 66.7
0.0 0.0 2.0 340 32.0 68.0 0.0 0.0 2.1 350 32.6 67.4 0.0 0.0 2.1
[0153] Referring to FIG. 10, it may be be seen that, at a 2-theta
(.theta.) value of 26 degree) (.degree. where peaks exist, the
intensity of the peak representing a rutile phase increased with
increasing deposition temperature. For example, crystallinity of
the rutile phase was observed at 300.degree. C., and it may be seen
that the crystallinity increased with increasing temperature. In
addition, the crystallinity could also be confirmed by the TEM
image shown in FIG. 9.
EXAMPLE 3
[0154] Synthesis of Compound Sn[N(Me).sub.2].sub.2Me.sub.2
[0155] 117 g (0.45 mol) of SnCl.sub.4 and 300 ml of n-hexane were
introduced into a 1,000 ml flask and mixed. 81.4 g (0.455 mol) of
Sn(Me).sub.4 was slowly added into the flask in an ice bath. The
components were stirred for about 2 hours, thereby completing
synthesis of SnMe.sub.2Cl.sub.2.
[0156] Next, 101 g (1.98 mol) of lithium dimethylamide (Li-DMA) was
diluted with ethyl ether and then slowly added into the flask. The
reaction was completed by stirring the components for 5 hours,
followed by removing a solvent and by-products at reduced
pressure.
[0157] Next, the resultant was purified at a temperature of
80.degree. C. and a pressure of 0.6 Torr, thereby obtaining 120 g
of a compound Sn[N(Me).sub.2].sub.2Me.sub.2 (yield: 56%).
[0158] The obtained compound underwent .sup.1H NMR analysis. The
results are shown in FIG. 11.
[0159] (Analysis)
[0160] .sup.1H NMR(C6D6): .delta. 2.76(s,12H), 0.09(s,6H)
EXAMPLE 4
[0161] A tin oxide thin film was formed in the same manner as in
Example 2 except that the compound Sn[N(Me).sub.2].sub.2Me.sub.2
was used instead of the compound Sn[N(iPr).sub.2].sub.2Me.sub.2,
and a deposition thickness of tin oxide per cycle was measured at
each deposition temperature. Results are shown in FIG. 12.
[0162] As shown in FIG. 12, it may be seen that the deposition
thickness per cycle changed along with the deposition temperature
varying from 200.degree. C. to 270.degree. C. Therefore, it may be
seen that a deposition mechanism other than ALD could have
contributed to the formation of the thin film at 200.degree. C. to
270.degree. C. Likewise, it may be seen that the deposition
thickness per cycle changed along with the deposition temperature
varying from 320.degree. C. to 400.degree. C. Therefore, it may be
seen that a deposition mechanism other than ALD, e.g., chemical
vapor deposition, could have contributed to the formation of the
thin film at 320.degree. C. to 400.degree. C.
[0163] It may be seen that the deposition thickness per cycle was
constant even when the deposition temperature varied in a range of
270.degree. C. to 320.degree. C. For example, in a temperature
range of 270.degree. C. to 320.degree. C., the tin oxide thin film
was formed by a mechanism of ALD.
COMPARATIVE EXAMPLE 1
[0164] Synthesis of Vompound Sn[N(Me).sub.2].sub.4
[0165] 100 g (0.35 mol) of SnCl.sub.4 and 300 ml of n-hexane were
introduced into a 1,000 ml flask and mixed. 80 g (1.57 mol) of
lithium dimethylamide (Li-DMA) was diluted with ethyl ether and
then slowly added into the flask in an ice bath, followed by
stirring the components at ambient temperature for 8 hours, thereby
completing the reaction. After completing the reaction, LiCl salts
were removed by filtering the product, thereby obtaining a
solution. Next, a solvent and by-products were removed from the
obtained solution at reduced pressure. After the removal of the
solvent, the solution was purified, thereby obtaining 63 g of a
compound Sn[N(Me).sub.2].sub.4 (yield: 70%).
[0166] (Analysis)
[0167] .sup.1H NMR(C6D6): .delta. 2.79(s,24H)
[0168] Formation of Tin Oxide Thin Film
[0169] A tin oxide thin film was formed in the same manner as in
Example 2 except that the compound Sn[N(Me).sub.2].sub.4 was used
instead of the compound Sn[N(iPr).sub.2].sub.2Me.sub.2, and a
deposition thickness of tin oxide per cycle was measured at each
deposition temperature. Results are shown in FIG. 13.
[0170] As shown in FIG. 13, the deposition thickness per cycle
decreased along with the deposition temperature varying from
100.degree. C. to 150.degree. C., and the deposition thickness per
cycle increased along with the deposition temperature increasing
from 150.degree. C. to 400.degree. C. For example, a temperature
range, in which the deposition thickness per cycle was constant,
was not observed. This means that a range allowing deposition by a
mechanism of ALD to be dominant was not present throughout the
whole temperature range when the compound Sn[N(Me).sub.2].sub.4 was
used. Therefore, the compound Sn[N(Me).sub.2].sub.4 may be
unsuitable as an ALD precursor.
[0171] When the compound Sn[N(Me).sub.2].sub.4 is used, there may
be no temperature range allowing deposition by the mechanism of ALD
to be dominant, and most deposition may be presumed to be performed
by a mechanism of CVD. Therefore, it may be difficult to form a
thin film with excellent step coverage on a surface of a structure
having a high aspect ratio.
COMPARATIVE EXAMPLE 2
[0172] A tin oxide thin film was formed in the same manner as in
Example 2 except that Sn(Me).sub.4 was used instead of the
Sn[N(iPr).sub.2].sub.2Me.sub.2, and a deposition thickness of tin
oxide per cycle was measured at each deposition temperature.
Results are shown in FIG. 14. The Sn(Me).sub.4 was a commercially
available product (Sigma-Aldrich Co., Ltd.), which had a 95%
grade.
[0173] As shown in FIG. 14, the deposition thickness per cycle
increased along with the deposition temperature varying from
250.degree. C. to 350.degree. C. For example, a temperature range,
in which the deposition thickness per cycle was constant, was not
observed. This means that a range allowing deposition by the
mechanism of ALD to be dominant was not present throughout the
whole temperature range. Therefore, the Sn(Me).sub.4 may be
unsuitable as an ALD precursor.
[0174] When Sn(Me).sub.4 was used, there was no temperature range
allowing deposition by the mechanism of ALD to be dominant, and
most deposition was presumed to be performed by the mechanism of
CVD. Therefore, it may be difficult to form a thin film with
excellent step coverage on a surface of a structure having a high
aspect ratio.
[0175] As is traditional in the field, embodiments are described,
and illustrated in the drawings, in terms of functional blocks,
units and/or modules. Those skilled in the art will appreciate that
these blocks, units and/or modules are physically implemented by
electronic (or optical) circuits such as logic circuits, discrete
components, microprocessors, hard-wired circuits, memory elements,
wiring connections, and the like, which may be formed using
semiconductor-based fabrication techniques or other manufacturing
technologies. In the case of the blocks, units and/or modules being
implemented by microprocessors or similar, they may be programmed
using software (e.g., microcode) to perform various functions
discussed herein and may optionally be driven by firmware and/or
software. Alternatively, each block, unit and/or module may be
implemented by dedicated hardware, or as a combination of dedicated
hardware to perform some functions and a processor (e.g., one or
more programmed microprocessors and associated circuitry) to
perform other functions. Also, each block, unit and/or module of
the embodiments may be physically separated into two or more
interacting and discrete blocks, units and/or modules without
departing from the scope herein. Further, the blocks, units and/or
modules of the embodiments may be physically combined into more
complex blocks, units and/or modules without departing from the
scope herein.
[0176] Example embodiments have been disclosed herein, and although
specific terms are employed, they are used and are to be
interpreted in a generic and descriptive sense only and not for
purpose of limitation. In some instances, as would be apparent to
one of ordinary skill in the art as of the filing of the present
application, features, characteristics, and/or elements described
in connection with a particular embodiment may be used singly or in
combination with features, characteristics, and/or elements
described in connection with other embodiments unless otherwise
specifically indicated. Accordingly, it will be understood by those
of skill in the art that various changes in form and details may be
made without departing from the spirit and scope of the present
invention as set forth in the following claims.
* * * * *