U.S. patent application number 14/312043 was filed with the patent office on 2015-12-24 for metal etchant compositions and methods of fabricating a semiconductor device using the same.
The applicant listed for this patent is Jihoon Jeong, Kyoungseob Kim, Yongsun Ko, Hyosan Lee, Kuntack Lee, Chen Lin, Christopher K. Ober. Invention is credited to Jihoon Jeong, Kyoungseob Kim, Yongsun Ko, Hyosan Lee, Kuntack Lee, Chen Lin, Christopher K. Ober.
Application Number | 20150368557 14/312043 |
Document ID | / |
Family ID | 54869074 |
Filed Date | 2015-12-24 |
United States Patent
Application |
20150368557 |
Kind Code |
A1 |
Lee; Hyosan ; et
al. |
December 24, 2015 |
METAL ETCHANT COMPOSITIONS AND METHODS OF FABRICATING A
SEMICONDUCTOR DEVICE USING THE SAME
Abstract
The present inventive concepts provide metal etchant
compositions and methods of fabricating a semiconductor device
using the same. The metal etchant composition includes an organic
peroxide in a range of about 0.1 wt % to about 20 wt %, an organic
acid in a range of about 0.1 wt % to about 70 wt %, and an
alcohol-based solvent in a range of about 10 wt % to about 99.8 wt
%. The metal etchant composition may be used in an anhydrous
system.
Inventors: |
Lee; Hyosan; (Hwaseong-si,
KR) ; Ko; Yongsun; (Suwon-si, KR) ; Kim;
Kyoungseob; (Suwon-si, KR) ; Lee; Kuntack;
(Suwon-si, KR) ; Jeong; Jihoon; (Suwon-si, KR)
; Lin; Chen; (Ithaca, NY) ; Ober; Christopher
K.; (Ithaca, NY) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Lee; Hyosan
Ko; Yongsun
Kim; Kyoungseob
Lee; Kuntack
Jeong; Jihoon
Lin; Chen
Ober; Christopher K. |
Hwaseong-si
Suwon-si
Suwon-si
Suwon-si
Suwon-si
Ithaca
Ithaca |
NY
NY |
KR
KR
KR
KR
KR
US
US |
|
|
Family ID: |
54869074 |
Appl. No.: |
14/312043 |
Filed: |
June 23, 2014 |
Current U.S.
Class: |
252/79.1 |
Current CPC
Class: |
H01L 21/76802 20130101;
H01L 2224/05666 20130101; C09K 13/08 20130101; C23F 1/26 20130101;
H01L 2924/04953 20130101; H01L 2224/0401 20130101; H01L 2924/20104
20130101; H01L 2224/05624 20130101; H01L 2924/20102 20130101; H01L
21/67017 20130101; C23F 1/18 20130101; H01L 21/31111 20130101; H01L
21/32134 20130101; H01L 21/6708 20130101; C23F 1/20 20130101; H01L
21/0273 20130101; H01L 2224/05647 20130101; H01L 2924/04941
20130101; H01L 2924/20103 20130101; H01L 2224/05684 20130101; H01L
2224/05681 20130101; H01L 21/02063 20130101; H01L 24/03 20130101;
H01L 24/11 20130101; H01L 2224/05571 20130101; H01L 2224/03614
20130101 |
International
Class: |
C09K 13/00 20060101
C09K013/00 |
Claims
1. A metal etchant composition comprising: an organic peroxide in a
concentration in a range of about 0.1 to about 20 wt. % based on
the total weight of the composition; an organic acid in a
concentration in a range of about 0.1 to about 70 wt. % based on
the total weight of the composition; and an alcohol-based solvent
in a concentration in a range of about 10 to about 99.8 wt. % based
on the total weight of the composition.
2. The metal etchant composition of claim 1, wherein at least one
of titanium (Ti), titanium nitride (TiN), tantalum (Ta), tantalum
nitride (TaN), aluminum (Al), tungsten (W), or copper (Cu) is
etched by the metal etchant composition.
3. The metal etchant composition of claim 1, wherein the organic
peroxide includes at least one peroxy ester having a structure of
Formula 1, at least one peroxy acid having a structure of Formula
2, at least one diacyl peroxide having a structure of Formula 3,
and/or at least one peroxy dicarbonate having a structure of
Formula 4, ##STR00003## wherein R and R' are each independently a
hydrocarbon compound.
4. The metal etchant composition of claim 3, wherein the organic
peroxide includes at least one of t-butyl peroxyacetic acid,
lauroyl peroxide, or ethyl peroxy dicarbonate.
5. The metal etchant composition of claim 1, wherein the organic
acid has a carbon compound structure including 3 to 11 fluorine
atoms or 3 to 35 hydrogen atoms.
6. The metal etchant composition of claim 5, wherein the organic
acid includes at least one of 2,2,2-trifluoroethanoic acid
(CF.sub.3COOH), 2,2,3,3,4,4,4-heptafluorobutanoic acid
(CF.sub.3CF.sub.2CF.sub.2COOH), acetic acid (CH.sub.3COOH), or
butanoic acid (CH.sub.3CH.sub.2CH.sub.2COOH).
7. The metal etchant composition of claim 1, wherein the
alcohol-based solvent includes 1 to 15 carbon atom(s).
8. The metal etchant composition of claim 7, wherein the
alcohol-based solvent includes at least one of methanol, ethanol,
propanol, isopropanol, heptanol, or octanol.
9. The metal etchant composition of claim 1, further comprising: a
chelating agent in a concentration in a range of about 0 to about 3
wt. % based on the total weight of the composition.
10. The metal etchant composition of claim 9, wherein the chelating
agent includes two or more carbonyl groups or two or more amine
groups.
11. The metal etchant composition of claim 10, wherein the
chelating agent includes at least one of
1,1,1,5,5,5-hexafluoro-2,4-pentanedione
[CF.sub.3C(O)CH.sub.2C(O)CF.sub.3],
1,1,1-trifluoro-2,4-pentanedione
[CH.sub.3C(O)CH.sub.2C(O)CF.sub.3], or pentane-2,4-dione
[CH.sub.3C(O)CH.sub.2C(O)CH.sub.3].
12. The metal etchant composition of claim 1, further comprising: a
surface active agent in a concentration in a range of about 0 to
about 3 wt. % based on the total weight of the composition.
13. The metal etchant composition of claim 12, wherein the surface
active agent is a fluorine-based surface active agent.
14.-22. (canceled)
23. A composition comprising: an organic peroxide; an organic acid;
and an alcohol-based solvent, wherein the composition is
anhydrous.
24. The composition of claim 23, wherein the organic peroxide and
the organic acid are present in the composition in a ratio in a
range of about 1:1 to about 1:5 (organic peroxide:organic
acid).
25. The composition of claim 23, wherein the composition provides
an etch rate of a metal layer of about 15 .ANG./hour to about 40
.ANG./hour.
26. The composition of claim 25, wherein the metal layer comprises
at least one of titanium (Ti), titanium nitride (TiN), tantalum
(Ta), tantalum nitride (TaN), aluminum (Al), tungsten (W), or
copper (Cu).
27. The composition of claim 23, wherein the organic peroxide is
present in a concentration in a range of about 0.1 to about 20 wt.
% based on the total weight of the composition, the organic acid is
present in a concentration in a range of about 0.1 to about 70 wt.
% based on the total weight of the composition, and the
alcohol-based solvent is present in a concentration in a range of
about 10 to about 99.8 wt. % based on the total weight of the
composition.
28. The composition of claim 23, further comprising a supercritical
fluid.
29. The composition of claim 23, wherein the composition generates
oxygen radicals.
30. (canceled)
Description
BACKGROUND
[0001] The present disclosure relates to metal etchant compositions
and methods of fabricating a semiconductor device using the
same.
[0002] As semiconductor devices have become highly integrated,
lines and spaces of interconnections in the semiconductor devices
have been reduced. Thus, fine-patterning techniques may be
desirable in processes for fabricating the interconnections. In
addition, low resistances of the interconnections may be
beneficial. Interconnection materials may include titanium,
tantalum, aluminum, and tungsten.
SUMMARY
[0003] Embodiments of the present inventive concepts may provide
metal etchant compositions capable of solving, preventing, and/or
reducing corrosion and collapse problems of a metal pattern.
[0004] Embodiments of the present inventive concepts may also
provide methods of fabricating a semiconductor device with improved
reliability.
[0005] In one aspect, a metal etchant composition may include an
organic peroxide in a range of about 0.1 wt % to about 20 wt %
based on the total weight of the composition; an organic acid in a
range of about 0.1 wt % to about 70 wt % based on the total weight
of the composition; and an alcohol-based solvent in a range of
about 10 wt % to about 99.8 wt % based on the total weight of the
composition.
[0006] In some embodiments, at least one of titanium (Ti), titanium
nitride (TiN), tantalum (Ta), tantalum nitride (TaN), aluminum
(Al), tungsten (W), or copper (Cu) may be etched by a metal etchant
composition of the present inventive concepts.
[0007] In some embodiments, the organic peroxide may include at
least one peroxy ester having a structure of Formula 1, at least
one peroxy acid having a structure of Formula 2, at least one
diacyl peroxide having a structure of Formula 3, and/or at least
one peroxy dicarbonate having a structure of Formula 4.
##STR00001##
[0008] In Formulas 1 to 4, R and R' are each independently a
hydrocarbon compound.
[0009] In some embodiments, the organic peroxide may include at
least one of t-butyl peroxyacetic acid, lauroyl peroxide, or ethyl
peroxy dicarbonate.
[0010] In some embodiments, the organic acid may have a carbon
compound structure in which the number of fluorine atoms is in a
range of 3 to 11 or the number of hydrogen atoms is in a range of 3
to 25.
[0011] In some embodiments, the organic acid may include at least
one of 2,2,2-trifluoroethanoic acid (CF.sub.3COOH),
2,2,3,3,4,4,4-heptafluorobutanoic acid
(CF.sub.3CF.sub.2CF.sub.2COOH), acetic acid (CH.sub.3COOH), or
butanoic acid (CH.sub.3CH.sub.2CH.sub.2COOH).
[0012] In some embodiments, the alcohol-based solvent may include a
carbon atom of which the number of carbon atoms is in a range of 1
to 15.
[0013] In some embodiments, the alcohol-based solvent may include
at least one of methanol, ethanol, propanol, isopropanol, heptanol,
or octanol.
[0014] In some embodiments, the metal etchant composition may
further include: a chelating agent in a range of about 0 wt % to
about 3 wt % based on the total weight of the composition.
[0015] In some embodiments, the chelating agent may include two or
more carbonyl groups or two or more amine groups.
[0016] In some embodiments, the chelating agent may include at
least one of 1,1,1,5,5,5-hexafluoro-2,4-pentanedione
[CF.sub.3C(O)CH.sub.2C(O)CF.sub.3],
1,1,1-trifluoro-2,4-pentanedione
[CH.sub.3C(O)CH.sub.2C(O)CF.sub.3], or pentane-2,4-dione
[CH.sub.3C(O)CH.sub.2C(O)CH.sub.3].
[0017] In some embodiments, the metal etchant composition may
further include: a surface active agent in a range of about 0 wt %
to about 3 wt % based on the total weight of the composition.
[0018] In some embodiments, the surface active agent may be a
fluorine-based surface active agent.
[0019] According to some embodiments, a composition of the present
inventive concepts may be anhydrous and may include an organic
peroxide, an organic acid, and an alcohol-based solvent.
[0020] In some embodiments, the organic peroxide and the organic
acid may be present in the composition in a ratio in a range of
about 1:1 to about 1:5 (organic peroxide:organic acid).
[0021] In some embodiments, the composition may provide an etch
rate of a metal layer of about 15 .ANG./hour to about 40
.ANG./hour. The metal layer may include at least one of titanium
(Ti), titanium nitride (TiN), tantalum (Ta), tantalum nitride
(TaN), aluminum (Al), tungsten (W), or copper (Cu).
[0022] In some embodiments, the composition may generate oxygen
radicals. The composition may etch a metal layer and/or generate
oxygen radicals for a period of time of up to about 10 hours after
application of the composition to the metal layer. In some
embodiments, the composition may substantially continuously etch a
metal layer and/or generate oxygen radicals for a period of time,
such as, but not limited to, up to about 10 hours or up to about 8
hours after application of the composition to the metal layer.
[0023] In some embodiments, a kit may be provided. The kit may
include one or more component(s) of a metal etchant composition of
the present inventive concepts, such as, but not limited to, an
organic peroxide, an organic acid, an alcohol-based solvent, a
chelating agent, a surface active agent, and/or a supercritical
fluid. The one or more component(s) in the kit may be used to
prepare the metal etchant composition. In some embodiments, at
least one component in the kit may be separately stored from the
other components in the kit. For example, in some embodiments, the
organic peroxide may be separately stored from the organic acid
and/or the alcohol-based solvent, or the organic acid may be
separately stored from the organic peroxide and/or the
alcohol-based solvent. In certain embodiments, each component in
the kit may be separately stored. The kit may contain one or more
component(s) in a particular amount or volume so that when the
components are combined to form the metal etchant composition a
desired amount of one or more component(s) in the composition
and/or a desired ratio is achieved.
[0024] In another aspect, a method of fabricating a semiconductor
device may include: providing a substrate having a metal-containing
layer formed thereon; and removing at least a portion of the
metal-containing layer using a metal etchant composition of the
present inventive concepts. In some embodiments, the providing step
comprises forming a metal-containing layer on the substrate.
[0025] In some embodiments, the method including providing a kit of
the present inventive concepts and combining and/or mixing the
components in the kit to form a metal etchant composition of the
present inventive concepts.
[0026] In some embodiments, removing the at least a portion of the
metal-containing layer may be performed or carried out in a
supercritical fluid. In some embodiments, the metal etchant
composition further comprises a supercritical fluid and/or the
metal etchant composition is used in the presence of a
supercritical fluid.
[0027] In some embodiments, the supercritical fluid may be a
supercritical carbon dioxide fluid. Removing the at least a portion
of the metal-containing layer may be performed at a temperature in
a range of about 31.degree. C. to about 100.degree. C. and at a
pressure in a range of about 73 bar to about 200 bar.
[0028] In some embodiments, the metal-containing layer may include
at least one of titanium (Ti), titanium nitride (TiN), tantalum
(Ta), tantalum nitride (TaN), aluminum (Al), tungsten (W), or
copper (Cu).
[0029] In some embodiments, removing the at least a portion of the
metal-containing layer may be performed at a temperature in a range
of about 20.degree. C. to about 80.degree. C.
[0030] In some embodiments, the method may further include, before
removing the at least a portion of the metal-containing layer,
forming an insulating layer covering the metal-containing layer and
etching the insulating layer to form an opening exposing the
metal-containing layer.
[0031] In some embodiments, the method may further include, before
removing the at least a portion of the metal-containing layer,
forming a photoresist pattern having an opening exposing a portion
of the metal-containing layer on the metal-containing layer and
removing the photoresist pattern.
[0032] In some embodiments, removing the at least a portion of the
metal-containing layer may be performed in an anhydrous system.
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] The above and other features and advantages of the
disclosure will become more apparent in view of the attached
drawings and accompanying detailed description.
[0034] FIG. 1 is a graph of an etched amount of a metal layer over
time according to various embodiments of the present inventive
concepts.
[0035] FIGS. 2 to 4 are cross-sectional views illustrating a method
of fabricating a semiconductor device according to various
embodiments of the present inventive concepts.
[0036] FIGS. 5 and 6 are schematic illustrations of cleaning
apparatuses according to various embodiments of the present
inventive concepts.
[0037] FIGS. 7 to 10 are cross-sectional views illustrating a
method of fabricating a semiconductor device according to various
embodiments of the present inventive concepts.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0038] Example embodiments are described below with reference to
the accompanying drawings. Many different forms and embodiments are
possible without deviating from the spirit and teachings of this
disclosure and so the disclosure should not be construed as limited
to the example embodiments set forth herein. Rather, these example
embodiments are provided so that this disclosure will be thorough
and complete, and will convey the scope of the disclosure to those
skilled in the art. In the drawings, the sizes and relative sizes
of layers and regions may be exaggerated for clarity. Like
reference numbers refer to like elements throughout the
description.
[0039] The terminology used herein is for the purpose of describing
particular embodiments only and is not intended to be limiting of
the embodiments. As used herein, the singular forms "a," "an," and
"the" are intended to include the plural forms as well, unless the
context clearly indicates otherwise. It will be further understood
that the terms "comprises," "comprising," "includes," and/or
"including," when used in this specification, specify the presence
of the stated features, steps, operations, elements, and/or
components, but do not preclude the presence or addition of one or
more other features, steps, operations, elements, components,
and/or groups thereof.
[0040] It will be understood that when an element is referred to as
being "coupled," "connected," or "responsive" to, or "on," another
element, it can be directly coupled, connected, or responsive to,
or on, the other element, or intervening elements may also be
present. In contrast, when an element is referred to as being
"directly coupled," "directly connected," or "directly responsive"
to, or "directly on," another element, there are no intervening
elements present. As used herein the term "and/or" includes any and
all combinations of one or more of the associated listed items.
[0041] 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's
relationship 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 term "below" can encompass both an orientation
of above and below. The device may be otherwise oriented (rotated
90 degrees or at other orientations) and the spatially relative
descriptors used herein may be interpreted accordingly.
[0042] If an embodiment is differently realizable, a specified
operation order may be differently performed from a described
order. For example, two consecutive operations may be substantially
simultaneously performed, or in an order opposite to the described
order.
[0043] Example embodiments of the inventive concepts are described
herein with reference to cross-sectional illustrations that are
schematic illustrations of idealized embodiments (and intermediate
structures) of example embodiments. As such, variations from the
shapes of the illustrations as a result, for example, of
manufacturing techniques and/or tolerances, are to be expected.
Thus, example embodiments of the inventive concepts should not be
construed as limited to the particular shapes of regions
illustrated herein but are to include deviations in shapes that
result, for example, from manufacturing. For example, an implanted
region illustrated as a rectangle may have rounded or curved
features and/or a gradient of implant concentration at its edges
rather than a binary change from implanted to non-implanted region.
Likewise, a buried region formed by implantation may result in some
implantation in the region between the buried region and the
surface through which the implantation takes place. Thus, the
regions illustrated in the figures are schematic in nature and
their shapes are not intended to illustrate the actual shape of a
region of a device and are not intended to limit the scope of
example embodiments.
[0044] It will be understood that although the terms "first,"
"second," etc. may be used herein to describe various elements,
these elements should not be limited by these terms. These terms
are only used to distinguish one element from another. Thus, a
"first" element could be termed a "second" element without
departing from the teachings of the present embodiments.
[0045] Unless otherwise defined, all terms (including technical and
scientific terms) used herein have the same meaning as commonly
understood by one of ordinary skill in the art to which this
inventive concept belongs. It will be further understood that
terms, such as those defined in commonly used dictionaries, should
be interpreted as having a meaning that is consistent with their
meaning in the context of the relevant art and/or the present
specification and will not be interpreted in an idealized or overly
formal sense unless expressly so defined herein.
[0046] A metal etchant composition according to the present
inventive concepts includes an organic peroxide in a range of about
0.1 wt % to about 20 wt % based on the total weight of the
composition, an organic acid in a range of about 0.1 wt % to about
70 wt % based on the total weight of the composition, and an
alcohol-based solvent in a range of about 10 wt % to about 99.8 wt
% based on the total weight of the composition.
[0047] The organic peroxide includes at least one peroxy ester
having a structure of Formula 1, at least one peroxy acid having a
structure of Formula 2, at least one diacyl peroxide having a
structure of Formula 3, and/or at least one peroxy dicarbonate
having a structure of Formula 4.
##STR00002##
[0048] In Formulas 1 to 4, R and R' are each independently a
hydrocarbon compound. For example, the organic peroxide may include
at least one of t-butyl peroxyacetic acid, lauroyl peroxide, or
ethyl peroxy dicarbonate. The organic peroxide may cause an active
oxidation reaction in an anhydrous system, and thus it may etch a
metal-containing layer. An organic peroxide may be suitable for a
cleaning process and/or an etching process. In some embodiments, an
organic peroxide may be decomposed relatively slowly. In addition,
an organic peroxide may have a higher stability and/or desirable
oxidizing power (or reactivity) with respect to a metal-containing
layer.
[0049] The organic acid may function as an initiator and may
activate the oxidation reaction of the organic peroxide and the
metal-containing layer. The organic acid may have a carbon compound
structure in which the number of fluorine atoms is in a range of 3
to 11 or the number of hydrogen atoms is in a range of 3 to 25. For
example, the organic acid may include at least one of
2,2,2-trifluoroethanoic acid (CF.sub.3COOH),
2,2,3,3,4,4,4-heptafluorobutanoic acid
(CF.sub.3CF.sub.2CF.sub.2COOH), acetic acid (CH.sub.3COOH), or
butanoic acid (CH.sub.3CH.sub.2CH.sub.2COOH).
[0050] The alcohol-based solvent may remove an etch by-product or a
by-product of a cleaning process. The alcohol-based solvent may
include a carbon atom of which the number of carbon atoms is in a
range of 1 to 15. For example, the alcohol-based solvent may
include at least one of methanol, ethanol, propanol, isopropanol,
heptanol, or octanol.
[0051] The metal etchant composition may further include a
chelating agent in a range of about 0 wt % to about 3 wt % based on
the total weight of the composition. The chelating agent may
include two or more carbonyl groups or two or more amine groups.
For example, the chelating agent may include at least one of
1,1,1,5,5,5-hexafluoro-2,4-pentanedione
[CF.sub.3C(O)CH.sub.2C(O)CF.sub.3],
1,1,1-trifluoro-2,4-pentanedione
[CH.sub.3C(O)CH.sub.2C(O)CF.sub.3], or pentane-2,4-dione
[CH.sub.3C(O)CH.sub.2C(O)CH.sub.3]. The chelating agent may protect
a surface of the metal-containing layer or may change a property of
the surface of the metal-containing layer.
[0052] The metal etchant composition may further include a surface
active agent in a range of about 0 wt % to about 3 wt % based on
the total weight of the composition. The surface active agent may
be a fluorine-based surface active agent. For example, the surface
active agent may include at least one of
R.sub.fCH.sub.2CH.sub.2SCH.sub.2CH.sub.2CO.sub.2Li,
(R.sub.fCH.sub.2CH.sub.2O).sub.2P(O)(ONH.sub.4).sub.2(R.sub.fCH.sub.2CH.s-
ub.2O).sub.2P(O)(ONH.sub.4),
(R.sub.fCH.sub.2CH.sub.2O)P(O)(OH).sub.2(R.sub.fCH.sub.2CH.sub.2O)2P(O)(O-
H), R.sub.fCH.sub.2CH.sub.2O(CH.sub.2CH.sub.2O).sub.xH,
R.sub.fCH.sub.2CH.sub.2SO.sub.3X wherein
R.sub.f.dbd.CF.sub.3(CF.sub.2CF.sub.2).sub.2, x=1.about.10, and X
is hydrogen (H) or an ammonium (NH.sub.4) ion, sodium
bis(2,2,3,3,4,4,5,5-octafluoro-1-pentyl)-2-sulfosuccinate,
polyethyleneoxide-block-polyfluorooctyl methacrylate, or
N-ethyl-4,4,5,5,6,6,7,7,8,8,9,9,9-tridecafluoro-N-methyl-N-(4,4,5,5,6,6,7-
,7,8,8,9,9,9-tridecafluorononyl)nonan-1-ammonium acetate. The metal
etchant composition may be well mixed with a supercritical fluid.
In some embodiments, the surface active agent may reduce and/or
minimize the occurrence of particles.
[0053] A metal-containing layer etchable by a metal etchant
composition of the present inventive concepts may include at least
one of titanium (Ti), titanium nitride (TiN), tantalum (Ta),
tantalum nitride (TaN), aluminum (Al), tungsten (W), or copper
(Cu).
[0054] The metal etchant composition may be applied in an anhydrous
system in which water does not exist. In some embodiments, water is
not directly added to the metal etchant composition as a distinct,
separate component of the composition. In some embodiments, the
metal etchant composition may be used by itself or the metal
etchant composition may be used in and/or with a supercritical
fluid.
[0055] In the metal etchant composition according to the present
inventive concepts, oxygen radicals may be activated from the
organic peroxide by the organic acid, and the alcohol-based solvent
may stabilize the activated oxygen radicals. As a result, an
effective metal etching reaction may be continuously caused by the
metal etchant composition according to the present inventive
concepts.
[0056] The metal etchant composition according to some embodiments
may be used in an anhydrous system and may be cleanly removed
without scum, such as, but not limited to, an etch by-product
and/or an etch residue. Thus, a process of using the metal etchant
composition may not need or require an additional cleaning process
using water, so the corrosion and collapse problems associated with
a metal pattern when water is utilized may not occur. In addition,
the metal etchant composition may not corrode the metal pattern.
Moreover, the metal etchant composition may have a low surface
tension and this may prevent the collapse of the metal pattern.
Furthermore, the metal etchant composition of the present inventive
concepts may be applied in a supercritical fluid. This feature may
be applied to a method of fabricating a semiconductor device, so
reliability of the semiconductor device may be improved.
[0057] According to some embodiments of the present inventive
concepts, a kit may be provided. The kit may include one or more
component(s) of a metal etchant composition of the present
inventive concepts, such as, but not limited to, an organic
peroxide, an organic acid, an alcohol-based solvent, a chelating
agent, a surface active agent, and/or a supercritical fluid. The
one or more component(s) in the kit may be used to prepare the
metal etchant composition. In some embodiments, the kit may include
an organic peroxide, an organic acid, and an alcohol-based
solvent.
[0058] In some embodiments, at least one component in the kit may
be separately stored from the other components in the kit. For
example, in some embodiments, the organic peroxide may be
separately stored from the organic acid and/or the alcohol-based
solvent, or the organic acid may be separately stored from the
organic peroxide and/or the alcohol-based solvent. In certain
embodiments, each component in the kit may be separately
stored.
[0059] The kit may contain one or more component(s) in a particular
amount or volume so that when the components are combined to form
the metal etchant composition a desired amount of one or more
component(s) in the composition and/or desired ratio is achieved.
For example, the kit may provide an organic peroxide and an organic
acid in a particular amount or volume so that the ratio of the
organic peroxide to the organic acid in the composition is in a
range of about 1:1 to about 1:5. In some embodiments, the organic
peroxide and organic acid are separately stored in the kit and when
they are combined with an alcohol-based solvent, which may be
separately stored or stored with one or more component(s) in the
kit, to form a metal etchant composition of the present inventive
concepts a desired ratio of the organic peroxide to the organic
acid in the composition is achieved.
[0060] A method of fabricating a semiconductor device using a metal
etchant composition according to the present inventive concepts
will be described in detail hereinafter.
[0061] FIGS. 2 to 4 are cross-sectional views illustrating a method
of fabricating a semiconductor device according to various
embodiments of the present inventive concepts.
[0062] Referring to FIG. 2, a metal-containing pattern 3 is formed
on a lower structure 1. The lower structure 1 may be a
semiconductor substrate. Alternatively, the lower structure 1 may
be a conductive pattern or an insulating layer formed on a
semiconductor substrate. The metal-containing pattern 3 may include
at least one of titanium (Ti), titanium nitride (TiN), tantalum
(Ta), tantalum nitride (TaN), aluminum (Al), tungsten (W), or
copper (Cu). An interlayer insulating layer 5 is formed on the
lower structure 1 having the metal-containing pattern 3. The
interlayer insulating layer 5 may be formed of a silicon
oxide-based material.
[0063] Referring to FIG. 3, the interlayer insulating layer 5 is
etched to form a via-hole 7 exposing the metal-containing pattern
3. Etch residues 9 may be formed on a top surface of the
metal-containing pattern 3 exposed by the via-hole 7. The etch
residues 9 may be etch by-products.
[0064] Referring to FIG. 4, a cleaning process is performed to
remove the etch residues 9. The cleaning process may be performed
using a metal etchant composition of the present inventive concepts
which etches the metal-containing pattern 3. The metal etchant
composition may be the same as a composition described herein.
[0065] The cleaning process may be performed using cleaning
apparatus 100 or 101 of FIG. 5 or 6.
[0066] Referring to FIG. 5, the cleaning apparatus 100 according to
an embodiment of the present inventive concepts includes first to
third raw-material tanks 30, 32, and 34, a mixing tank 36, a
cleaning chamber 38, a pump 43, and pipes 41 and 45. An organic
peroxide may be stored in the first raw-material tank 30. An
organic acid may be stored in the second raw-material tank 32. An
alcohol-based solvent may be stored in the third raw-material tank
34. These raw materials may be mixed with each other in composition
ratios, such as, but not limited to those described herein, within
mixing tank 36 to form a metal etchant composition. The metal
etchant composition in mixing tank 36 may be forcibly mixed by pump
43 and a first pipe 41. The mixed metal etchant composition may be
transferred to the cleaning chamber 38 through a second pipe 45. An
injection nozzle 47 is installed at one end of the second pipe 45.
A chuck 49 on which a wafer W is loaded may be disposed in the
cleaning chamber 38. The chuck 49 may be an electrostatic chuck or
a vacuum chuck. The chuck 49 may be rotatable. An exhaust pipe 51
may be connected to a lower portion of the cleaning chamber 38. The
patterns illustrated in FIG. 3 may be formed on the wafer W. The
wafer W may be rotated, and the metal etchant composition may
jetted, dripped, sprayed, and/or the like onto a top surface of the
wafer W. An inner space of the cleaning chamber may be maintained
at a temperature in a range of 20.degree. C. to 80.degree. C. The
pressure in the inner space of the cleaning chamber may be
atmospheric pressure. The metal etchant composition may be
exhausted and/or removed through exhaust pipe 51.
[0067] The cleaning process using the cleaning apparatus 100 of
FIG. 5 may be performed with an organic material in an anhydrous
system in which water is not present. Since the cleaning process is
performed with a metal etchant composition of the present inventive
concepts containing an alcohol-based solvent having a surface
tension lower than that of water, it may be possible to prevent
patterns from collapsing. In addition, corrosion of the
metal-containing pattern 3 may not occur by using a composition
and/or process according to the present inventive concepts.
[0068] Referring to FIG. 6, a cleaning apparatus 101 according to
another embodiment of the present inventive concepts includes first
to third raw-material tanks 30, 32, and 34, a mixing tank 36, a
cleaning chamber 38a, pumps 43 and 64, pipes 41, 45, 46a, 46b, and
46c, storage units 66 and 68, a temperature controller 62, and a
carbon dioxide (CO.sub.2)-storing tank 60. Like FIG. 5, an organic
peroxide, an organic acid, and an alcohol-based solvent may be
stored in the first raw-material tank 30, the second raw-material
tank 32, and the third raw-material tank 34, respectively. These
raw materials may be mixed with each other in defined composition
ratios within mixing tank 36 to form a metal etchant composition.
The metal etchant composition in mixing tank 36 may be forcibly
mixed by pump 43 and a first pipe 41. The mixed metal etchant
composition may then be transferred to a first storage unit 66
through a second pipe 45. Carbon dioxide may be outputted from the
carbon dioxide-storing tank 60 and then converted into a
supercritical fluid using a high-pressure pump 64 and a temperature
controller 62. Here, the temperature of the supercritical carbon
dioxide fluid may be in a range of about 31.degree. C. to about
100.degree. C., and the pressure of the supercritical carbon
dioxide fluid may be in a range of about 73 bar to about 200 bar.
The supercritical carbon dioxide fluid may be divided and stored in
the first storage unit 66 and a second storage unit 68 through a
third pipe 46a. The supercritical carbon dioxide fluid may be mixed
with the metal etchant composition in the first storage unit 66. An
injection nozzle 47 may be installed at one end of each of the
fourth and fifth pipes 46b and 46c respectively connected to the
first and second storage units 66 and 68. A chuck 49 on which a
wafer W is loaded may be disposed in the cleaning chamber 38a. The
chuck 49 may be an electrostatic chuck or a vacuum chuck. The chuck
49 may be rotatable. Inner spaces of the third to fifth pipes 46a,
46b, and 46c, inner spaces of the storage units 66 and 68, and an
inner space of the cleaning camber 38a may be maintained at a
temperature in the range of about 31.degree. C. to about
100.degree. C. and at a pressure in the range of about 73 bar to
about 200 bar.
[0069] A cleaning process using the cleaning apparatus 101 of FIG.
6 may be performed in a supercritical fluid in an anhydrous system
in which water is not present. Since the supercritical carbon
dioxide fluid has a surface tension lower than that of water, it
may be possible to prevent patterns from collapsing. In addition,
the supercritical carbon dioxide fluid does not remain as a residue
and/or by-product on the wafer W after the cleaning process and
thus using a composition and/or process according to the present
inventive concepts may solve problems associated with a remaining
solvent. Further, corrosion of the metal-containing pattern 3 may
not occur by using a composition and/or process according to the
present inventive concepts.
[0070] FIGS. 7 to 10 are cross-sectional views illustrating a
method of fabricating a semiconductor device according to various
embodiments of the present inventive concepts.
[0071] Referring to FIG. 7, a conductive pad 12 is formed on a
lower structure 10. The lower structure 10 may include a
semiconductor substrate with circuit patterns and an interlayer
insulating layer formed on the semiconductor substrate. A first
passivation layer 14 and a second passivation layer 16 are formed
on the conductive pad 12 and the lower structure 10. The first and
second passivation layers 14 and 16 expose a portion of the
conductive pad 12 and cover the lower structure 10. The first
passivation layer 14 may include, for example, a silicon nitride
layer, and the second passivation layer 16 may include, for
example, a polyimide layer. A metal-containing layer 18 is
conformally formed on an entire top surface of the lower structure
10 having the first and second passivation layers 14 and 16. The
metal-containing layer 18 may be formed of, for example, a titanium
layer and a copper-containing layer. The titanium layer may act as
an adhesion layer and/or a diffusion-preventing layer, and the
copper-containing layer may act as a seed layer. A photoresist
pattern 20 is formed on the metal-containing layer 18. The
photoresist pattern 20 is formed to have an opening that exposes
the metal-containing layer 18 overlapping with the conductive pad
12. A planting process is performed to form a bump 22 filling the
opening on the metal-containing layer 18 not covered by the
photoresist pattern 20. The bump 22 may include at least one of
lead (Pb), nickel (Ni), or tin (Sn).
[0072] Referring to FIG. 8, the photoresist pattern 20 is removed
to expose the metal-containing layer 18. The photoresist pattern 20
may be removed by an ashing process.
[0073] Referring to FIG. 9, the exposed metal-containing layer 18
is removed using a metal etchant composition of the present
inventive concepts. The metal etchant composition may be the same
as or similar to a metal etchant composition described herein. The
etching process of the metal-containing layer 18 using the metal
etchant composition may be the same as or similar to a cleaning
process using a cleaning apparatus 100 and/or 101 as described
herein. As a result, a metal-containing pattern 18a remains under
bump 22, and a top surface of the second passivation layer 16 is
exposed.
[0074] Referring to FIG. 10, the bump 22 may be reflowed by heat to
form a globular bump 22a.
[0075] As described above, a method of fabricating a semiconductor
device can be performed using a metal etchant composition of the
present inventive concepts. However, the applications of a metal
etchant composition according to the present inventive concepts are
not limited to the embodiments described herein.
[0076] In a metal etchant composition according to embodiments of
the present inventive concepts, oxygen radicals may be activated
from the organic peroxide by the organic acid and the alcohol-based
solvent may stabilize the activated oxygen radicals. As a result,
an effective metal etching reaction may be continuously caused to
effectively and stably etch a metal. In addition, the metal etchant
composition may be used in an anhydrous system to cleanly remove
scum such as, but not limited to, etch by-products and etch
residues. Thus, a process using a metal etchant composition
according to the present inventive concepts does not need an
additional cleaning process using water. This may prevent the
corrosion and/or collapse problems caused by water when used with a
metal pattern.
[0077] A metal etchant composition of the present inventive
concepts may not corrode the metal pattern. Additionally, the metal
etchant composition may have a low surface tension, so collapse of
the metal pattern may be prevented. Furthermore, the metal etchant
composition can be used in a supercritical fluid. As a result, the
metal etch composition may be applied to a method of fabricating a
semiconductor device to improve the reliability of the
semiconductor device.
[0078] Experimental examples using a metal etchant composition
according to the present inventive concepts will be described
hereinafter.
EXAMPLES
Example 1
[0079] This first experimental example was performed to determine
an etched amount of a titanium nitride (TiN) layer using a metal
etchant composition according to the present inventive
concepts.
[0080] Three metal etchant compositions were prepared with each
optionally including t-butyl peroxyacetic acid as the organic
peroxide, 2,2,3,3,4,4,4-heptafluorobutanoic acid
(CF.sub.3CF.sub.2CF.sub.2COOH) as the organic acid, and isopropyl
alcohol as the alcohol-based solvent.
[0081] The first metal etchant composition (i.e., the first
condition) was a solution including the organic peroxide in an
amount of 5.5 wt % and the organic acid in an amount of 94.5 wt
%.
[0082] The second metal etchant composition (i.e., the second
condition) was a solution including the organic acid in an amount
of 63.5 wt % and the alcohol-based solvent in an amount of 36.5 wt
%.
[0083] The third metal etchant composition (i.e., the third
condition) was a solution including the organic peroxide in an
amount of 3.5 wt %, the organic acid in an amount of 61.3 wt %, and
the alcohol-based solvent in an amount of 35.2 wt %.
[0084] Wafers having a titanium nitride layer were obtained. A
wafer was dipped in one of the three compositions at a temperature
of 60.degree. C. for a predetermined process time. The wafers were
unloaded from the compositions after the predetermined process time
and were then rinsed with isopropyl alcohol. Thereafter, the wafers
were dried using nitrogen. Next, the thickness of the remaining
titanium nitride layer was measured to determine the etched amount
of the titanium nitride layer on each of the wafers. FIG. 1 is a
graph of the etched amount of the titanium nitride layer according
to the process time.
[0085] Referring to FIG. 1, it was determined that the third
composition including all three components (i.e., the organic
peroxide, the organic acid, and the alcohol-based solvent) has
excellent etch-ability. If either the organic peroxide or the
alcohol-based solvent is omitted, the titanium nitride layer is
hardly etched. As a result, it is confirmed that the
metal-containing layer can be effectively etched by a metal etchant
composition including an organic peroxide, an organic acid, and an
alcohol-based solvent according to the present inventive
concepts.
Example 2
[0086] This second experimental example was performed to determine
an etched amount of a titanium nitride (TiN) layer using metal
etchant compositions containing various solvents.
[0087] Each of the metal etchant compositions in this second
experimental example included t-butyl peroxyacetic acid as the
organic peroxide and 2,2,3,3,4,4,4-heptafluorobutanoic acid
(CF.sub.3CF.sub.2CF.sub.2COOH) as the organic acid. Each of the
compositions included one of the following solvents: isopropyl
alcohol, ethanol, N,N-dimethyl formaldehyde (DMF), acetone,
toluene, or 1,1,1,3,3,3-hexafluoro-2-propanol (F-IPA). Each of the
compositions in this example included the organic peroxide in an
amount of 11.1 wt %, the organic acid in an amount of 36.5 wt %,
and the solvent in an amount of 52.4 wt %.
[0088] Wafers having the titanium nitride layer were obtained. A
wafer was dipped in one of the respective compositions at a
temperature of 60.degree. C. for 8 hours. The wafers were unloaded
from each of the compositions after 8 hours and were then rinsed
with isopropyl alcohol. Thereafter, the wafers were dried using
nitrogen. Next, the thickness of the remaining titanium nitride
layer on each wafer was measured to confirm the etched amount of
the titanium nitride layer. Table 1 shows the etched amount of the
titanium nitride layer according to the solvent present in the
composition.
TABLE-US-00001 TABLE 1 Solvent Isopropyl alcohol Ethanol DMF
Acetone Toluene F-IPA Etched amount 244 244 14 15 2 1 of TiN
(.ANG.)
[0089] Referring to Table 1, the etched amount of the titanium
nitride layer is high when the solvent is an alcohol-based solvent
such as isopropyl alcohol or ethanol. On the other hand, the etched
amount of the titanium nitride layer is low when the solvent is a
non-alcohol-based solvent such as DMF, acetone, toluene, or F-IPA.
As a result, an alcohol-based solvent is suitable for the metal
etchant compositions according to the present inventive
concepts.
Example 3
[0090] This third experimental example was performed to determine
the etched amounts of various layers when etched by a metal etchant
composition of the present inventive concepts.
[0091] Each of the metal etchant compositions in this second
experimental example included t-butyl peroxyacetic acid as the
organic peroxide and 2,2,3,3,4,4,4-heptafluorobutanoic acid
(CF.sub.3CF.sub.2CF.sub.2COOH) as the organic acid. Each of the
compositions included isopropyl alcohol as the alcohol-based
solvent. Each of the compositions in this example included the
organic peroxide in an amount of 11.1 wt %, the organic acid in an
amount of 36.5 wt %, and the solvent in an amount of 52.4 wt %.
Wafers having one of the following layers were prepared: a titanium
nitride layer, a silicon oxide layer, a silicon nitride layer, or a
poly-silicon layer. Each of the wafers was dipped in the
composition at a temperature of 60.degree. C. for 10 hours. Each of
the wafers was unloaded from the composition after the 10 hours and
was then rinsed with isopropyl alcohol. Subsequently, each of the
wafers was dried using nitrogen. Thereafter, the thickness of the
remaining portion of each layer was measured to determine an etched
amount of each layer. Table 2 shows the etched amount of the
various layers etched by a composition of the present inventive
concepts.
TABLE-US-00002 TABLE 2 Layer Titanium Silicon Silicon Poly- nitride
layer oxide layer nitride layer silicon layer Etched amount 249 0.3
0.1 0.7 (.ANG.)
[0092] Referring to Table 2, the titanium nitride layer was
sufficiently etched by the composition of the present inventive
concepts. On the other hand, the other layers tested (i.e., the
silicon oxide layer, the silicon nitride layer, and the
poly-silicon layer) were hardly etched by the composition of the
present inventive concepts. As shown in Table 2, an etch ratio of
the titanium nitride layer to another layer using the composition
of the present inventive concepts is about 250:1 or more.
Example 4
[0093] In this fourth experimental example, a metal etchant
composition of the present inventive concepts was applied in a
supercritical carbon dioxide (CO.sub.2) fluid.
[0094] Compositions were prepared as set forth in Table 3. The
first composition (Composition #1) included t-butyl peroxyacetic
acid (t-BPA) as the organic peroxide. Compositions #2-4 each
included t-butyl peroxy benzoic acid (t-BPBA) as the organic
peroxide. Compositions #1-4 each included
2,2,3,3,4,4,4-heptafluorobutanoic acid
(CF.sub.3CF.sub.2CF.sub.2COOH; F3) as the organic acid.
Compositions #1-3 each included isopropyl alcohol (IPA) as the
alcohol-based solvent. Composition #4 included a mixed solution of
ethanol, butanol, heptanol, and decanol as the alcohol-based
solvent. Each of Compositions #1-4 included the organic peroxide in
an amount of 11.1 wt %, the organic acid in an amount of 36.5 wt %,
and the alcohol-based solvent in an amount of 52.4 wt %.
[0095]
N-ethyl-4,4,5,5,6,6,7,7,8,8,9,9,9-tridecafluoro-N-methyl-N-(4,4,5,5-
,6,6,7,7,8,8,9,9,9-tridecafluorononyl)nonan-1-aminium acetate
(QAS-4) was added as a surface active agent in Composition #2. The
amount of the surface active agent was 0.05 wt % with respect to
the total weight of Composition #2. Therefore, Composition #2
includes the organic peroxide in an amount of 11.09445 wt %, the
organic acid in an amount of 36.48175 wt %, the alcohol-based
solvent in an amount of 52.3738 wt % and the surface active agent
in an amount of 0.05 wt %.
[0096] Wafers having titanium nitride layers were obtained. The
cleaning processes were performed in a cleaning apparatus 100 of
FIG. 5 or a cleaning apparatus 101 of FIG. 6. Etch rates of the
titanium nitride layers during the cleaning processes are shown in
Table 3,
TABLE-US-00003 TABLE 3 Result of experiment Composition Etch rate
Etch rate Com- Or- of TiN in of TiN in posi- Or- ganic Alcohol- a
liquid supercritical tion ganic perox- based Addi- state CO.sub.2
fluid # acid ide solvent tive (.ANG./minute) (.ANG./hour) 1 F3
t-BPA IPA -- 25 17 or more 2 F3 t-BPBA IPA QAS-4 23 20 or more 3 F3
t-BPBA IPA -- 25 15 or more 4 F3 t-BPBA ethanol, -- 20 or more 15
or more butanol, heptanol, decanol
[0097] Referring to Table 3, the etch rates of TiN using one of
Compositions #1-4 in a liquid state were obtained from titanium
nitride (TiN) layers etched using the cleaning apparatus 100 of
FIG. 5. The etch rates of TiN using one of Compositions #1-4 in
supercritical CO.sub.2 fluid were obtained from titanium nitride
(TiN) layers etched using the cleaning apparatus 101 of FIG. 6.
Here, a supplied amount of the supercritical CO.sub.2 fluid was 20
cc. As shown in Table 3, the metal etchant compositions of the
present inventive concepts can etch the titanium nitride layer in
the supercritical CO.sub.2 fluid as well as the liquid state. As a
result, the metal etchant composition of the present inventive
concepts can be used in supercritical CO.sub.2 fluid.
[0098] While the inventive concepts have been described with
reference to example embodiments, it will be apparent to those
skilled in the art that various changes and modifications may be
made without departing from the spirits and scopes of the inventive
concepts. Therefore, it should be understood that the above
embodiments are not limiting, but illustrative. Thus, the scopes of
the inventive concepts are to be determined by the broadest
permissible interpretation of the following claims and their
equivalents, and shall not be restricted or limited by the
foregoing description.
* * * * *