U.S. patent application number 09/884992 was filed with the patent office on 2001-12-06 for use of alkoxy n-hydroxyalkyl alkanamide as resist removing agent, composition for removing resist, method for preparing the same and resist removing method using the same.
Invention is credited to Chon, Sang-Mun, Gil, June-Ing, Hwang, Jin-Ho, Park, Dong-Jin, Park, Je-Eung.
Application Number | 20010049346 09/884992 |
Document ID | / |
Family ID | 27532279 |
Filed Date | 2001-12-06 |
United States Patent
Application |
20010049346 |
Kind Code |
A1 |
Park, Dong-Jin ; et
al. |
December 6, 2001 |
Use of alkoxy N-hydroxyalkyl alkanamide as resist removing agent,
composition for removing resist, method for preparing the same and
resist removing method using the same
Abstract
A resist removing agent and a resist removing composition,
having an excellent capability for removing a resist and polymer
and which does not attack underlying layers, a method for preparing
the same and a resist removing method using the same. The resist
removing agent includes alkoxy N-hydroxyalkyl alkanamide. The
resist removing composition includes alkoxy N-hydroxyalkyl
alkanamide, and at least one compound selected from a group
consisting of a polar material having a dipole moment of 3 or
greater, an attack inhibitor and alkanolamine. A substrate having
the resist thereon is brought into contact with the resist removing
agent or resist removing composition to remove the resist.
Inventors: |
Park, Dong-Jin; (Osan-city,
KR) ; Hwang, Jin-Ho; (Suwon-city, KR) ; Gil,
June-Ing; (Hwasung-gun, KR) ; Park, Je-Eung;
(Suwon-city, KR) ; Chon, Sang-Mun; (Sungnam-city,
KR) |
Correspondence
Address: |
JONES VOLENTINE, LLC
SUITE 150
12200 SUNRISE VALLEY DRIVE
RESTON
VA
20191
US
|
Family ID: |
27532279 |
Appl. No.: |
09/884992 |
Filed: |
June 21, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09884992 |
Jun 21, 2001 |
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09348829 |
Jul 8, 1999 |
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6274537 |
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09348829 |
Jul 8, 1999 |
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09140334 |
Aug 26, 1998 |
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09348829 |
Jul 8, 1999 |
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09140333 |
Aug 26, 1998 |
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Current U.S.
Class: |
510/175 ;
510/176; 510/499; 510/501 |
Current CPC
Class: |
G03F 7/425 20130101 |
Class at
Publication: |
510/175 ;
510/176; 510/499; 510/501 |
International
Class: |
C11D 001/00 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 5, 1998 |
KR |
98-32354 |
Aug 5, 1998 |
KR |
98-32355 |
Jun 7, 1999 |
KR |
99-20973 |
Claims
What is claimed is:
1. A resist removing agent comprising alkoxy N-hydroxyalkyl
alkanamide.
2. The resist removing agent according to claim 1, wherein the
alkoxy N-hydroxyalkyl alkanamide is of the formula
(I):R.sub.4--O--R.sub.3--CO--- N--R.sub.1R.sub.2OH (I)wherein:
R.sub.1 is a hydrogen atom, a C.sub.1 to C.sub.5 hydrocarbon, or an
aromatic hydrocarbon having 1 to 3 rings, R.sub.2 is a C.sub.1 to
C.sub.5 hydrocarbon or an aromatic hydrocarbon having 1 to 3 rings,
and R.sub.3 and R.sub.4 are, independently, a C.sub.1 to C.sub.5
hydrocarbon.
3. The resist removing agent according to claim 2, wherein R.sub.1
is hydrogen, R.sub.2 is --CH.sub.2CH.sub.2--, R.sub.3 is
--CH.sub.2CH.sub.2--, and R.sub.4 is --CH.sub.3.
4. A resist removing composition comprising: alkoxy N-hydroxyalkyl
alkanamide; and at least one of a polar material having a dipole
moment of 3 or greater and an attack inhibitor.
5. The resist removing composition according to claim 4, wherein
the alkoxy N-hydroxyalkyl alkanamide is of the formula
(I):R.sub.4--O--R.sub.3--CO--N--R.sub.1R.sub.2OH (I)wherein:
R.sub.1 is hydrogen, a C.sub.1 to C.sub.5 hydrocarbon, or an
aromatic hydrocarbon having 1 to 3 rings, R.sub.2 is a C.sub.1 to
C.sub.5 hydrocarbon or an aromatic hydrocarbon having 1 to 3 rings,
and R.sub.3 and R.sub.4 are, independently, a C.sub.1 to C.sub.5
hydrocarbon.
6. The resist removing composition according to claim 4, wherein
the polar material is one selected from a group consisting of
water, methanol and dimethylsulfoxide.
7. The resist removing composition according to claim 4, wherein
the attack inhibitor is a compound represented by formula
(II):R.sub.6--(OH).sub.n (II)wherein: R.sub.6 is a C.sub.1 to
C.sub.5 hydrocarbon, a C.sub.1 to C.sub.5 hydrocarbon having a
--COOH group, an aromatic hydrocarbon having 1 to 3 rings, or an
aromatic hydrocarbon having 1 to 3 rings and a --COOH group in at
least one ring, and n is an integer from 1 to 4.
8. The resist removing composition according to claim 4, wherein
the alkoxy N-hydroxyalkyl alkanamide is in a range from about 30 to
about 99.9 weight % of the resist removing composition.
9. The resist removing composition according to claim 4, wherein
the polar material and the attack inhibitor are, independently, in
a range from about 0.01 to about 30 weight % of the resist removing
composition.
10. A resist removing composition comprising: alkoxy N-hydroxyalkyl
alkanamide; and alkanolamine.
11. The resist removing composition according to claim 10, further
comprising at least one of a polar material having a dipole moment
of 3 or greater and an attack inhibitor.
12. The resist removing composition according to claim 10, wherein
the alkoxy N-hydroxyalkyl alkanamide is of the formula
(I):R.sub.4--O--R.sub.3--CO--N--R.sub.1R.sub.2OH (I)wherein:
R.sub.1 is a hydrogen atom, a C.sub.1 to C.sub.5 hydrocarbon, or an
aromatic hydrocarbon having 1 to 3 rings, R.sub.2 is a C.sub.1 to
C.sub.5 hydrocarbon or an aromatic hydrocarbon having 1 to 3 rings,
and R.sub.3 and R.sub.4 are, independently, a C.sub.1 to C.sub.5
hydrocarbon.
13. The resist removing composition according to claim 10, wherein
the alkanolamine is of the following formula
(III):R.sub.1--NH--R.sub.2OH (II)wherein: R.sub.1 is hydrogen, a
C.sub.1 to C.sub.5 hydrocarbon, or an aromatic hydrocarbon having 1
to 3 rings; and R.sub.2 is a C.sub.1 to C.sub.5 hydrocarbon or an
aromatic hydrocarbon having 1 to 3 rings.
14. The resist removing composition according to claim 11, wherein
the polar material is one selected from a group consisting of
water, methanol and dimethylsulfoxide.
15. The resist removing composition according to claim 11, wherein
the attack inhibitor is a compound represented by formula
(II):R.sub.6--(OH).sub.n (II)wherein: R.sub.6 is a C.sub.1 to
C.sub.5 hydrocarbon, a C.sub.1 to C.sub.5 hydrocarbon having a
--COOH group, an aromatic hydrocarbon having 1 to 3 rings, or an
aromatic hydrocarbon having 1 to 3 rings having a --COOH group; and
n is an integer from 1 to 4.
16. The resist removing composition according to claim 10, wherein
the alkoxy N-hydroxyalkyl alkanamide is in a range from about 30 to
about 99.9 weight % of the resist removing composition.
17. The resist removing composition according to claim 10, wherein
the alkanolamine is in a range from about 0.1 to about 70 weight %
of the resist removing composition.
18. The resist removing composition according to claim 11, wherein
the polar material and the attack inhibitor are, independently, in
a range from about 0.01 to about 30 weight % of the resist removing
composition.
19. The resist removing composition according to claim 11, wherein
the alkoxy N-hydroxyalkyl alkanamide, the alkanolamine, the polar
material and the attack inhibitor are in a range from about 40 to
about 65 weight % of the resist removing composition, in a range
from about 5 to about 30 weight % of the resist removing
composition, in a range from about 5 to about 20 weight % of the
resist removing composition, and in a range from about 5 to about
20 weight % of the resist removing composition, respectively.
20. A method for preparing alkoxy N-hydroxyalkyl alkanamide
comprising: mixing alkanolamine and alkyl alkoxy alkanoate; and
reacting the mixture of alkanolamine and alkyl alkoxy alkanoate to
form alkoxy N-hydroxyalkyl alkanamide.
21. The method according to claim 20, wherein, during said mixing,
the alkanolamine is of the formula (III):R.sub.1--NH--R.sub.2OH
(III)wherein: R.sub.1 is hydrogen, a C.sub.1 to C.sub.5
hydrocarbon, or an aromatic hydrocarbon having 1 to 3 rings, and
R.sub.2 is a C.sub.1 to C.sub.5 hydrocarbon or an aromatic
hydrocarbon having 1 to 3 rings, and the alkyl alkoxy alkanoate is
of the formula (IV):R.sub.4--O--R.sub.3--CO- O--R.sub.5 (IV)wherein
R.sub.3, R.sub.4 and R.sub.5 are, independently, a C.sub.1 to
C.sub.5 hydrocarbon.
22. The method according to claim 21, wherein, during said mixing,
the alkanolamine is in a range from about 10 to about 70 weight %
of the resist removing composition and the alkyl alkoxy alkanoate
in a range from about 10 to 70 weight % of the resist removing
composition.
23. The method according to claim 20, wherein, during said mixing,
further mixing at least one of a polar material having a dipole
moment of 3 or greater and an attack inhibitor.
24. The resist removing composition according to claim 23, wherein,
during said mixing, the polar material and the attack inhibitor
are, independently, in a range from about 0.01 to about 30 weight %
of the resist removing composition.
25. The method according to claim 20, wherein said reacting is
performed at a temperature in a range from room temperature to
about 120.degree. C.
26. The method according to claim 25, after said reacting, further
comprising removing alcohol produced as a by-product of the
reacting.
27. A resist removing method comprising: providing a substrate;
forming a resist on the substrate; and contacting the substrate
with a resist removing agent comprising alkoxy N-hydroxyalkyl
alkanamide or a resist removing composition to remove the resist
from the substrate, the resist removing composition comprising
alkoxy N-hydroxyalkyl alkanamide, and at least one compound
selected from a group consisting of a polar material having a
dipole moment of 3 or greater, an attack inhibitor, and
alkanolamine.
28. The method according to claim 27, wherein, during said
contacting, the alkoxy N-hydroxyalkyl alkanamide is of the formula
(I):R.sub.4--O--R.sub.3--CO--N--R.sub.1R.sub.2OH (I)wherein:
R.sub.1 is a hydrogen atom, a C.sub.1 to C.sub.5 hydrocarbon, or an
aromatic hydrocarbon having 1 to 3 rings, R.sub.2 is a C.sub.1 to
C.sub.5 hydrocarbon or an aromatic hydrocarbon having 1 to 3 rings,
and R.sub.3 and R.sub.4 are, independently, a C.sub.1 to C.sub.5
hydrocarbon.
29. The method according to claim 27, wherein, during said
contacting, the polar material is one selected from a group
consisting of water, methanol and dimethylsulfoxide.
30. The method according to claim 27, wherein, during said
contacting, the attack inhibitor is a compound represented by
formula (II):R.sub.6--(OH).sub.n (II)wherein: R.sub.6 is a C.sub.1
to C.sub.5 hydrocarbon, a C.sub.1 to C.sub.5 hydrocarbon having a
--COOH group, an aromatic hydrocarbon having 1 to 3 rings, or an
aromatic hydrocarbon having 1 to 3 rings having a --COOH group; and
n is an integer from 1 to 4.
31. The method according to claim 27, wherein, during said
contacting, the alkanolamine is of the following formula
(III):R.sub.1--NH--R.sub.2OH (III)wherein: R.sub.1 is hydrogen, a
C.sub.1 to C.sub.5 hydrocarbon, or an aromatic hydrocarbon having 1
to 3 rings; and R.sub.2 is a C.sub.1 to C.sub.5 hydrocarbon or an
aromatic hydrocarbon having 1 to 3 rings.
32. The method according to claim 27, wherein, during said
contacting, the alkoxy N-hydroxyalkyl alkanamide is in a range from
about 30 to about 99.9 weight % of the resist removing
composition.
33. The method according to claim 27, wherein, during said
contacting, the polar material and the attack inhibitor are,
independently, in a range from about 0.01 to about 30 weight % of
the resist removing composition.
34. The method according to claim 27, wherein, during said
contacting, the alkanolamine is in a range from about 0.1 to about
70 weight % of the resist removing composition.
35. The method according to claim 27, wherein, during said
contacting, the alkoxy N-hydroxyalkyl alkanamide, the alkanolamine,
the polar material and the attack inhibitor are in a range from
about 40 to about 65 weight % of the resist removing composition,
in a range from about 5 to about 30 weight % of the resist removing
composition, in a range from about 5 to about 20 weight % of the
resist removing composition, and in a range from about 5 to about
20 weight % of the resist removing composition, respectively.
36. The method according to claim 27, after said contacting,
further comprising: rising the substrate; and drying the
substrate.
37. The method according to claim 36, before said contacting,
further comprising ashing the substrate.
38. The method according to claim 27, wherein said contacting is
performed at a temperature in a range from about 45.degree. C. to
about 70.degree. C.
Description
[0001] This application is a continuation-in-part (CIP) of
application Ser. Nos. 09/140,334 and 09/140,333 filed Aug. 26, 1998
and assigned to the assignee of the present application, each
disclosure of which is incorporated herein by reference in its
entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a resist removing agent, a
composition for removing resist, a method for preparing the same
and a resist removing method using the same. In particular, the
present invention relates to use of an alkoxy N-hydroxyalkyl
alkanamide as a resist removing agent, a composition for removing
resist, a method for preparing the same, and a resist removing
method using the same.
[0004] 2. Description of the Related Art
[0005] The resist removing process is a major process in preparing
a semiconductor device. After various processes for preparing a
semiconductor device, e.g., an etching process (dry or wet) or an
ion implantation process, a resist pattern used as a mask must be
removed. Also, in the case when the resist pattern is misaligned,
it must be removed to form a new resist pattern. In particular,
various different material layers, e.g., an oxide layer, an
aluminum layer, a copper layer, a polysilicon layer, a silicide
layer or a polyimide layer, may be present under a resist layer to
be removed. Therefore, an important consideration for a resist
removing process is to remove a resist completely, as quickly as
possible, and without attacking underlying layers.
[0006] A resist removing agent currently in wide use includes a
basic amine such as hydroxyamine, diglycolamine, monoethanolamine
or methylethanolamine, and a polar solvent such as water or
alcohol, as its essential components.
[0007] Since such conventional resist removing agents cannot remove
polymer completely, a pre-removal step for removing polymer is
further necessary. Polymer is a material produced by reaction of
components constituting the resist pattern, such as carbon (C),
hydrogen (H), or oxygen (O), and plasma when plasma etching or
reactive ion etching (RIE) is performed to etch the underlying
layers using the resist pattern as a mask. Particularly, when a
metal layer is formed under the resist pattern, an organometallic
polymer is produced. If such a polymer or organometallic polymer is
not removed, but remains in a contact hole or a via hole, contact
resistance increases. Thus, before using the resist removing agent,
a cleaning reinforcement agent capable of removing polymer, e.g., a
nitric acid solution (HNO.sub.3), must be used to treat the
substrate during a pre-removal step.
[0008] The conventional resist removing agent may attack the
underlying layers. A typical example of an underlying layer liable
to be attacked is a metal layer. The reason for the foregoing is
because the resist removal agent is mainly comprised of a basic
solvent or water which easily corrodes the metal layer. Thus, a
post-removal step for preventing the attack must be further carried
out before executing a post-removal rinse step. In the post-removal
step, isopropyl alcohol (IPA) is used for example.
[0009] Therefore, since a nitric acid treatment step (i.e., a
pre-removal step) and an isopropyl alcohol treatment step (i.e., a
post-removal step) are further performed, the resist removal
process becomes more complicated and processing time is prolonged,
thereby lowering productivity. Also, since a pre-removal material,
e.g., nitric acid and a post-removal material, e.g., isopropyl
alcohol, are further required as well as the resist removal
material, the manufacturing cost increases. In addition, since
various baths for the pre-removal step and the post-removal step
are required, a resist removing apparatus becomes unnecessarily
bulky.
SUMMARY OF THE INVENTION
[0010] A first objective of the present invention is to provide a
resist removing agent having an excellent capability for removing a
resist and polymer and which does not attack underlying layers
exposed to the resist removing agent.
[0011] A second objective of the present invention is to provide a
composition for removing resist, having an excellent capability for
removing a resist and polymer and which does not attack underlying
layers exposed to the resist removing agent.
[0012] A third objective of the present invention is to provide a
method for preparing the resist removing agent.
[0013] A fourth objective of the present invention is to provide a
method for removing a resist using the resist removing
composition.
[0014] Accordingly, to achieve the above objectives and other
objects and advantages of the present invention, there is provided
a resist removing agent comprising alkoxy N-hydroxyalkyl
alkanamide.
[0015] In another aspect of the present invention, the resist
removing composition includes alkoxy N-hydroxyalkyl alkanamide, and
at least one of a polar material having a dipole moment of 3 or
greater and an attack inhibitor.
[0016] According to another aspect of the present invention, the
resist removing composition includes alkoxy N-hydroxyalkyl
alkanamide and alkanolamine. The composition may further include at
least one of a polar material having a dipole moment of 3 or
greater and an attack inhibitor.
[0017] In another aspect of the present invention, the method for
preparing alkoxy N-hydroxyalkyl alkanamide includes mixing
alkanolamine and alkyl alkoxy alkanoate, and reacting the mixture
of alkanolamine and alkyl alkoxy alkanoate.
[0018] To achieve the fourth objective, there is provided a method
for removing resist including providing a substrate, forming a
resist on the substrate, contacting the substrate with a resist
removing agent comprising alkoxy N-hydroxyalkyl alkanamide or a
resist removing composition to remove the resist from the
substrate, the resist removing composition comprising alkoxy
N-hydroxyalkyl alkanamide, and at least one compound selected from
the group consisting of a polar material having a dipole moment of
3 or greater, an attack inhibitor, and alkanolamine.
[0019] The resist removing agent or resist removing composition
according to the present invention has an excellent capability for
removing the resist, and is capable of effectively removing polymer
and organometallic polymer, and does not attack the underlying
layers exposed to the resist removing agent or composition.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is a flow diagram, wherein the solid lines indicate a
process of removing a resist and polymer using a resist removing
agent or a resist removing composition according to the present
invention, and the dashed lines indicate the conventional steps
eliminated by using the present invention;
[0021] FIG. 2 is a block diagram of a resist removing apparatus
using a resist removing agent or a resist removing composition
according to the present invention;
[0022] FIG. 3 is a schematic diagram of a horizontal type resist
removing apparatus using a resist removing agent or a resist
removing composition according to the present invention;
[0023] FIG. 4 is a schematic diagram of a vertical type resist
removing apparatus using a resist removing agent or a resist
removing composition according to the present invention;
[0024] FIG. 5 is a scanning electron microscopic photograph
illustrating the removal result of the resist pattern using the
resist removing composition according to the present invention;
[0025] FIG. 6 is a scanning electron microscopic photograph
illustrating the removal result of the resist pattern using the
conventional resist removing composition;
[0026] FIG. 7 is a cross-sectional view of a substrate having a
copper layer, which is not treated with a resist removing
composition;
[0027] FIG. 8 is a cross-sectional view of a substrate having a
copper layer, which is treated with a resist removing composition
according to the present invention;
[0028] FIG. 9 is a cross-sectional view of a substrate having a
copper layer, which is treated with a conventional resist removing
composition;
[0029] FIG. 10 is a graph illustrating the observation result for
the copper layer formed on a substrate using Auger Electron
Spectroscopy before the substrate having a copper layer is treated
with a resist removing composition according to the present
invention;
[0030] FIG. 11 is a graph illustrating the observation result for
the copper layer formed on a substrate using Auger Electron
Spectroscopy after the substrate having a copper layer is treated
with a resist removing composition according to the present
invention; and
[0031] FIG. 12 is a graph illustrating the change in contents of
components of the resist composition, measured by gas
chromatography for 48 hours at intervals of 8 hours.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0032] Hereinbelow, a resist removing agent and a resist removing
composition according to the present invention will be described,
and a method for preparing the same, a method for removing a resist
using the same, and a resist removing apparatus used in the resist
removing method will be described in detail. The present invention
may, however, be embodied in many different forms and should not be
construed as limited to the embodiments set forth herein. Rather,
these embodiments are provided so that this disclosure will be
thorough and complete, and will fully convey the scope of the
present invention to those skilled in the art.
Resist Removing Agent
[0033] A resist removing agent according to the present invention
includes an alkoxy N-hydroxyalkyl alkanamide. In detail, the alkoxy
N-hydroxyalkyl alkanamide is represented by formula (I):
R.sub.4--O--R.sub.3--CO--N--R.sub.1R.sub.2OH (I)
[0034] wherein R.sub.1 is a hydrogen atom, a C.sub.1 to C.sub.5
hydrocarbon (i.e., a non-ring hydrocarbon with 1 to 5 carbon
atoms), or an aromatic hydrocarbon having 1 to 3 rings; R.sub.2 is
a C.sub.1 to C.sub.5 hydrocarbon or an aromatic hydrocarbon having
1 to 3 rings; and R.sub.3and R.sub.4are each any of the C.sub.1 to
C.sub.5 hydrocarbons, independent of each other.
[0035] In the preferred embodiment, R.sub.1 is a hydrogen atom,
R.sub.2 is --CH.sub.2CH.sub.2--, R.sub.3 is --CH.sub.2CH.sub.2--,
and R.sub.4 is --CH.sub.3.
[0036] The resist removing agent according to the present invention
contains a hydroxy group (--OH), an alkoxy group (--OR.sub.4) and a
carbonyl group (C.dbd.O). Consequently, the resist removing agent
according to the present invention is very effective in exfoliation
and dissolution of a resist and polymer.
[0037] Also, as shown in the following reaction formula (1), the
resist removing agent reacts with an organometallic polymer,
thereby easily removing the organometallic polymer from the surface
of a substrate:
[0038] (Reaction formula 1) 1
[0039] wherein Mp represents an organometallic polymer.
Resist Removing Composition
Embodiment 1
[0040] A resist removing composition according to a first
embodiment of the present invention includes an alkoxy
N-hydroxyalkyl alkanamide, and at least one of a polar material
having a dipole moment of 3 or greater and an attack inhibitor.
[0041] The alkoxy N-hydroxyalkyl alkanamide is a compound
represented by the above-described formula (I).
[0042] The polar material having a dipole moment of 3 or greater
exhibits a high solubility with respect to cross-linked polymer and
resist. In other words, the polymer strongly bonded on the side
walls of the resist pattern and the surface of the exposed
underlying layer can be effectively removed by such polar material.
Also, resist removal itself is facilitated by such polar material.
For the polar material having a dipole moment of 3 or greater,
water, methanol or dimethyl sulfoxide may be employed.
[0043] The attack inhibitor prevents various layers exposed to the
resist removing composition, particularly, metal layers, from being
attacked. The attack inhibitor is represented by the following
formula (II):
R.sub.6--(OH).sub.n (II)
[0044] wherein R.sub.6 is a C.sub.1 to C.sub.5 hydrocarbon, a
C.sub.1 to C.sub.5 hydrocarbon having a --COOH group, an aromatic
hydrocarbon having 1 to 3 rings, or an aromatic hydrocarbon having
1 to 3 rings and a --COOH group in at least one ring. The integer n
may have a value between and inclusive of 1 and 4.
[0045] Particularly, it is preferred that R.sub.6 is a benzene ring
and the attack inhibitor is catechol in which n is 2. Also, gallic
acid is a widely known attack inhibitor represented by formula (II)
that may be used within the present invention.
[0046] The attack inhibition mechanism for a metal layer is
illustrated by the following reaction formula (2) for the case when
the attack inhibitor is catechol:
[0047] (Reaction formula 2) 2
[0048] wherein M represents a metal.
Embodiment 2
[0049] A resist removing composition according to a second
embodiment of the present invention includes the alkoxy
N-hydroxyalkyl alkanamide and alkanolamine.
[0050] The alkanolamine is a compound represented by the following
formula (III):
R.sub.1--NH--R.sub.2OH (III)
[0051] wherein R.sub.1 is hydrogen, a C.sub.1 to C.sub.5
hydrocarbon or an aromatic hydrocarbon having 1 to 3 rings, and
R.sub.2 is a C.sub.1 to C.sub.5 hydrocarbon or an aromatic
hydrocarbon having 1 to 3 rings. In a preferred embodiment R.sub.1
is hydrogen and R.sub.2 is monoethanolamine, that is,
--CH.sub.2CH.sub.2--.
[0052] The alkanolamine is also effective in removing an
organometallic polymer. The organometallic polymer removing
mechanism of the alkanolamine is represented by the following
reaction formula (3) for the case of monoethanolamine:
[0053] (Reaction formula 3) 3
[0054] wherein Mp represents an organometallic polymer.
[0055] Preferably, the resist removing composition according to a
second embodiment of the present invention further includes at
least one of the polar material having a dipole moment of 3 or
greater and the attack inhibitor.
[0056] The resist removing compositions according to the present
invention and weight % of various components are expressed in the
following Table 1. In Table 1, the contents of the preferred
compositions are given in parentheses.
1TABLE 1 Resist Removing Compositions Alkoxy N-hydroxy- Composition
alkyl Alkanol Polar Attack for removing alkanamide amine material
inhibitor resist (weight %) (weight %) (weight %) (weight %) 1 30
to 99.99 0.01 to 70 2 30 to 99.99 0.01 to 70 3 30 to 99.98 0.01 to
40 0.01 to 40 (40 to 60) (20 to 30) (20 to 30) 4 30 to 99.9 0.1 to
70 5 30 to 99.89 0.1 to 40 0.01 to 30 6 30 to 99.89 0.1 to 40 0.01
to 30 7 30 to 99.88 0.1 to 40 0.01 to 30 0.01 to 30 (40 to 65) (5
to 30) (5 to 20) (5 to 20)
[0057] The contents of the above-described compositions are optimal
contents in which a resist and polymer can be effectively removed,
and the layer underlying the resist, e.g., a metal layer, exposed
to a resist removing agent or a resist removing composition, is
minimally attacked by such compositions.
[0058] Among the above compositions, compositions 3 and 7, which
include both a polar material and an attack inhibitor, are the most
effective for removing resist and polymer. Also, in the case when
there is a metal layer underlying the resist, they do attack the
metal layer.
[0059] However, compositions 1, 4 and 5, which do not include an
attack inhibitor, may also achieve the same effect as compositions
3 and 7 in the case when a material normally attacked by a resist
removing composition, such as a metal layer, is not exposed to the
resist removing composition. Also, compositions 2, 4 and 6, which
do not include a polar material having a dipole moment of 3 or
greater, may also achieve the same effect as compositions 3 and 7
in the case when attack inhibition of a metal layer is a more
important factor, the amount of polymer to be removed is very
small, or a pre-removal step has been carried out.
[0060] As described above, the resist removing agent or resist
removing compositions have excellent capability for removing the
resist and the polymer which is an etching by-product. Also, they
do not attack the layer underlying the resist, e.g., a metal layer.
In addition, the above-described materials are cheaper than the
components of the conventional resist removing compositions.
Method for Preparing Resist Removing Agent
[0061] An alkoxy N-hydroxyalkyl alkanamide according to the present
invention is prepared by reacting alkanolamine represented by
formula (III) and alkyl alkoxy alkanoate represented by formula
(IV), as represented by the following reaction formula (4):
[0062] (Reaction formula 4) 4
[0063] wherein R.sub.1 is a hydrogen atom, a C.sub.1 to C.sub.5
hydrocarbon, or an aromatic hydrocarbon having 1 to 3 rings;
R.sub.2 is a C.sub.1 to C.sub.5 hydrocarbon or an aromatic
hydrocarbon having 1 to 3 rings; and R.sub.3, R.sub.4 and R.sub.5
are each any of the C.sub.1 to C.sub.5 hydrocarbons, independent of
each other.
[0064] The alkanolamine is preferably monoethanolamine in which
R.sub.1 is a hydrogen atom and R.sub.2 is --CH.sub.2CH.sub.2--, and
the alkyl alkoxy alkanoate is preferably methyl methoxy propanoate
in which R.sub.3 is --CH.sub.2CH.sub.2--, R.sub.4 is --CH.sub.3 and
R.sub.5 is --CH.sub.3.
[0065] Here, to supply energy sufficient for this reaction, the
reaction temperature is maintained at a temperature in the range
from room temperature to about 120.degree. C. In the preferred
embodiment of the method, the mixture is heated to a temperature in
the range from about 80.degree. C. to about 90.degree. C.
[0066] As understood from the above reaction formula, amine (III)
is reacted with ester (IV) to produce amide (I) and alcohol
(V).
[0067] While the alcohol (V) is a C.sub.1 to C.sub.5 alcohol having
a low boiling point, for example, methanol with a boiling point of
about 60.degree. C., the amide (I) is a material having a high
boiling point, for example, methoxy N-hydroxyethyl propaneamide
with a boiling point of about 200.degree. C. Therefore, the alcohol
(V) is removed using fractional distillation to obtain an amide (I)
compound.
[0068] Preferably, fractional distillation is performed together
with a nitrogen bubbling in the reaction bath, or vaporization of
the alcohol (V) is facilitated by reducing the pressure of the
reaction bath. Of course, the two methods may be adopted
simultaneously.
Method for Preparing Resist Removing Composition
[0069] The resist removing compositions shown in Table 1 are
prepared by first preparing an alkoxy N-hydroxyalkyl alkanamide
according to the present invention in the above-described manner
and then mixing thereto at least one material selected from the
group consisting of an attack inhibitor, a material having a dipole
moment of 3 or greater, and alkanolamine, in the range of contents
as shown in Table 1.
[0070] Also, the compositions 1 through 7 shown in Table 1 can be
prepared as follows.
[0071] First, at least one of 0.01 to 30 weight % of an attack
inhibitor and 0.01 to 30 weight % of a polar material, 10 to 70
weight % (preferably 30 to 40 weight %) of alkanolamine and 10 to
70 weight % (preferably, 30 to 40 weight %) of alkyl alkoxy
alkanoate are mixed. Preferably, the alkanolamine and alkyl alkoxy
alkanoate are mixed in a mixture ratio in which the total amount of
alkyl alkoxy alkanoate can completely react with alkanolamine to be
converted into amide. The temperature of the mixture is maintained
at a temperature in a range from room temperature to about
120.degree. C. Preferably, the mixture is heated to a temperature
in the range from about 80.degree. C. to about 90.degree. C. The
reaction time is 1 to 24 hours, preferably 1 to 12 hours. After the
heating is completed, the reactant is left alone for 1 to 7
hours.
[0072] The completion of the reaction can be verified visually or
by gas chromatography. In visual verification, layer separation
among components is observed to vanish as the reaction progresses.
When the separate component layers are observed to completely
vanish, the completion of the reaction is presumed. When the
composition is analyzed using gas chromatography, the area
percentile of N alkanol alkoxy alkanamide exceeding 80% implies
completion of the reaction. Area percentile is defined as the area
under a peak in the gas chromatography spectrum associated with a
component, divided by the sum of the areas under all peaks of all
components, and the quotient multiplied by 100.
[0073] Subsequently, in order to remove alcohol having a low flash
point generated as a by-product, fractional distillation is
performed. Fractional distillation is performed together with a
nitrogen bubbling in the reaction bath, or vaporization of the
alcohol is facilitated by reducing the pressure of the reaction
bath. Also, the two methods may be adopted simultaneously.
Preferably, the fractional distillation is performed so that 7 to 8
weight % or less of alcohol remains with respect to the total
amount of composition.
Method for Removing Resist
[0074] The steps of removing the resist using the resist removing
agent and resist removing composition according to the present
invention will be described with reference to the solid line steps
in FIG. 1. Note that the conventional process is represented by
both the solid line and the dashed line steps in FIG. 1 Various
processes for completing a semiconductor device, for instance, an
etching (dry or wet) process or an ion implantation process, are
performed using a resist pattern as a mask. Then, an ashing step,
which is a dry stripping process, is performed on the substrate
where the resist pattern is formed (step 110). The ashing step can
be omitted. Subsequently, a substrate where the resist pattern is
formed is allowed to contact a resist removing agent or a resist
removing composition listed in Table 1 to remove the resist or
polymer or both (step 120). This is achieved by placing the resist
removing agent or the resist removing composition in a bath and
then dipping the substrate into the bath. Alternatively, the resist
removing agent or the resist removing composition may be sprayed
onto the substrate as the substrate is moved through the spray.
[0075] In the case of using the resist removing agent or the resist
removing compositions according to the present invention, the
resist removal step is performed at a low temperature of about
70.degree. C. or below, specifically, in the range from room
temperature to 70.degree. C., preferably, from 45.degree. C. to
70.degree. C. A contact time in the range from about 10 to about 30
minutes is preferred.
[0076] The resist removed by the resist removing agent or resist
removing composition according to the present invention can be
applied to a resist suitable for short wavelength exposure such as
a resist for an ArF excimer laser (193 nm), a resist for a
conventional i-line (365 nm) resist, or a resist for a KrF excimer
laser (248 nm).
[0077] After the resist is completely removed, the resist removing
agent, the resist removing composition and the dissolved resist
remaining on the substrate are rinsed away (step 140). The rinsing
step is performed using a rinsing solution, e.g., deionized water.
If necessary, the rinsing step can be performed in two steps.
Finally, the substrate is dried by a spin drying method or a drying
method using isopropyl alcohol to remove the deionized water
remaining on the substrate (step 150).
[0078] After the drying step 150, the substrate is transferred for
subsequent processing. When a resist is used again in a subsequent
step, the used resist is again removed through the steps shown in
FIG. 1 after the intended subsequent step is completed. The
semiconductor device is completed through such repeated unit
fabrication processes and resist removal steps.
[0079] As shown in FIG. 1, since the resist removing agent or
resist removing composition according to the present invention has
an excellent capability for removing the resist or polymer, the
pre-removal step 100 (dashed lines) is not necessary, unlike the
conventional art. Also, since the layer underlying the resist is
prevented from being attacked, the post-removal step 130 (dashed
lines) can be omitted, also unlike the conventional art. Thus,
according to the present, the resist can be completely removed by a
simple process, compared to the conventional resist removing
process. Therefore, the productivity of semiconductor devices can
be remarkably enhanced.
Resist Removing Apparatus
[0080] As described above, since the resist removal process is
simplified, the resist removing apparatus according to the present
invention can be made smaller or more compact.
[0081] Referring to FIG. 2, a resist removing apparatus 200
according to the present invention simply includes a resist removal
unit 210, a rinsing unit 220 and a drying unit 230. That is, the
conventional pre-removal unit and post-removal unit are not
necessary. Thus, the area occupied by the resist removing apparatus
200 can be significantly reduced as compared to the conventional
art.
[0082] In the case that the resist removing apparatus 200 employs a
dipping method, the units 210, 220 and 230 each correspond to an
independent bath. Thus, unlike the conventional art, a nitric acid
(HNO.sub.3) pre-removal treatment bath and an isopropyl alcohol
(IPA) post-removal treatment bath are not necessary, thereby
eliminating two baths and significantly reducing the area occupied
by the resist removing apparatus 200.
[0083] A resist removing apparatus employing a spray method can be
classified into a horizontal type and a vertical type.
[0084] Referring to FIG. 3, a horizontal type resist removing
apparatus 300 employs a horizontal carrier means 340, e.g., a
conveyor system, a handler, or an arm, and is sectioned into a
resist removing unit 310, a rinsing unit 320 and a drying unit 330.
A source 360 containing a resist removing agent or a resist
removing composition of the present invention supplies the resist
removing agent or resist removing composition to the resist
removing unit 310 through a supply unit 370. A rinsing solution
unit source 362 and a drying agent unit source 364 are also
connected to the rinse unit and the drying unit 330 through the
supply unit 370, respectively. Nozzles 312, 322 and 332 are
installed in the units for spraying materials suitable for
functions of the respective units. In operation, when a substrate
is loaded into the resist removing unit 310, a resist removing
agent or resist removing composition is sprayed from the nozzle 312
to remove the resist. Here, the substrate is continuously conveyed
horizontally, by the carrier 340 toward the rinsing unit 320. A
rinsing solution is sprayed in the rinsing unit 320 through the
nozzle 322. Finally, the substrate is conveyed to the drying unit
330 by the carrier 340 to then be dried by a drying agent, such as
air or a drying chemical directed onto the substrate by the nozzle
332. Since the horizontal type resist removing apparatus includes
only three units, the size of the apparatus is significantly
reduced.
[0085] Referring to FIG. 4, a vertical type resist removing
apparatus 400 employs a vertically movable substrate support 440.
The vertical type also includes a source 460 of the resist removing
agent or the resist removing composition of the present invention
and a supply unit 470 to supply the resist removing agent or resist
removing composition. In the preferred embodiment, the substrate
support 440 is rotatable. Also, the inside of the apparatus is
constructed of three areas, in a bedded structure, vertically
displaced with respect to each other, and not independent chambers.
That is, the units are composed of a drying area 430, a rinsing
area 420 and a resist removal area 410 in vertical sequence. A
rinsing solution source 462 and a drying agent source 464 are
connected to a supply duct 450 through the supply unit 470. In the
embodiment, a single supply duct 450 sequentially provides the
respective materials for all three units.
[0086] When a substrate (not shown) on which a resist is formed is
loaded onto the substrate support 440, the support 440 first moves
to an area where the resist removal is performed and a resist
removing agent or resist removing composition from the source 460
via the supply unit 470 is sprayed through the supply duct 450. In
the preferred embodiment, the resist removing agent or resist
removing composition is discharged to the outside through an
exhaust duct (not shown). When the resist removal step is
completed, the substrate support 440 moves the substrate to the
rinsing unit 420 by descending. A rinsing solution is then sprayed
into the rinsing unit 420 through the supply duct 450. Finally, the
substrate is then carried to the drying unit 430 by the vertical
movement of the substrate support 440 to be dried. Although FIG. 4
shows that the drying unit 430, the rising unit 420 and the resist
removing unit 410 are disposed vertically in sequence from bottom
to top, these units may be vertically disposed in a reverse order.
Because the vertical type resist removing apparatus of the present
invention also includes only three units, the size of the apparatus
is significantly reduced compared to a conventional vertical type
apparatus.
[0087] The further details of the present invention are described
with reference to the following examples, but it is understood that
the invention is not limited to these specific examples.
EXAMPLE I
Preparation of Methoxy N-Hydroxyethyl Propanamide
[0088] 200 ml of monoethanolamine as an alkanolamine and 200 ml of
methyl methoxy propanoate as an ester were mixed. Subsequently, the
mixture was heated at 90.degree. C. for 5 hours. After heating, the
reactant was restored to room temperature for 5 hours.
[0089] The resultant material was analyzed by gas chromatography to
ascertain that the methoxy N-hydroxyethyl propanamide product was
obtained. In addition, the product was analyzed by proton nuclear
magnetic resonance (.sup.1H-NMR) spectrum giving relative amounts
of components in parts per million (ppm). The NMR data of the
product is as follows: 6.8 ppm (1H), 3.7-3.8 ppm (4H), 3.4-3.5 ppm
(3H), and 2.8-2.9 ppm (1H).
EXAMPLE II
Preparation of Methoxy N Butyl Hydroxyethyl Propanamide
[0090] 200 ml of N,N t-butyl ethanolamine as an alkanolamine and
200 ml of methyl methoxy propanoate as an ester were mixed.
Subsequently, the mixture was heated at 90.degree. C. for 5 hours.
After heating, the reactant was restored to room temperature for 5
hours.
[0091] The obtained resultant material was analyzed by gas
chromatography to ascertain that the methoxy N butyl hydroxyethyl
propanamide product was obtained.
EXAMPLE III
Evaluation of an Appropriate Temperature in Preparing Methoxy N
Hydroxyethyl Propanamide
[0092] 200 ml of monoethanolamine (MEA) as an alkanolamine and 200
ml of methyl methoxy propanoate (MMP) as an ester were mixed.
Subsequently, to ascertain the temperature suitable for the
reaction of amine and ester, the methoxy N hydroxyethyl propanamide
was synthesized at different temperatures as shown in Table 2 and
the time consumed for the synthesis to be complete was measured.
The timing for completion of the synthesis was determined by the
elapsed time until the area % of the amide (methoxy N hydroxyethyl
propanamide) exceeds 80% as analyzed by gas chromatography.
2TABLE 2 methoxy N hydroxyethyl propanamide Reaction Temperatures
and Times Reaction temperature (.degree. C.) 25 35 45 55 65 80 90
Reaction time (hr) 55 24 30 7 6 4 3
[0093] From the above result, it was understood that the reaction
does occur at room temperature and that the reaction occurs more
rapidly at higher temperatures. However, in consideration of other
processing conditions, it is preferable that the reaction
temperature does not exceed 120.degree. C. Thus, the temperature
for preparing the amide compound according to the present invention
is desirably between room temperature and about 120.degree. C. In
the preferred embodiment of the method, the reacting temperature is
in the range from about 80.degree. C. to about 90.degree. C.
EXAMPLE IV
Preparation of Resist Removing Composition and Evaluation of Same
to Remove the Resist
[0094] As shown in Table 3, seven (7) resist removing compositions
were prepared with MEA, MMP, catechol and water of different
contents. Subsequently, the compositions were heated at 80.degree.
C. for 5 hours. Next, the resultant material was placed at room
temperature for 6 hours. Then, methanol was removed by fractional
distillation in which a nitrogen bubbling and a reduced pressure
method are both adopted, to complete the compositions.
[0095] The resist to be removed using the above-described resist
removing composition was prepared in the following manner on each
of 7 sheets of substrates. First, BoroPhosphoSilicate Glass (BPSG)
layers were formed to a thickness of 5000 .ANG. on 7 sheets of
substrates, respectively. Then, a titanium layer and a titanium
nitride layer were formed to a thickness of 200 .ANG.,
respectively, and heated. Next, an aluminum layer was deposited to
a thickness of 6000 .ANG. and then flowed. A titanium nitride layer
as a capping layer was formed on the aluminum layer and then an
interlevel dielectric layer was formed to a thickness of 10000
.ANG.. Then, a resist was coated on the interlevel dielectric layer
and then photolithography was performed to form a resist pattern
defining a via hole. The resist pattern was baked and then the
interlevel dielectric layer was etched, using the resist pattern as
a mask, by a buffered oxide etchant to form a via hole exposing the
aluminum layer.
[0096] After forming the via hole, the 7 substrates were ashed and
dipped into 7 respective baths containing the 7 respective
compositions listed in Table 3. The temperatures of the baths were
maintained at 60.degree. C. After being submerged for 20 minutes,
the substrates were rinsed with water for 5 minutes and dried, and
then the substrates were examined using scanning electron
microscopy (SEM). The substrates were graded as good, better, best
based on the SEM observations, and the grades are indicated in
Table 3 using symbols. The state of the substrate is characterized
by the relative amounts of remaining polymer and remaining
resist.
3TABLE 3 Resist Removing Performance of Several Compositions Item
MEA(ml) MMP(ml) Catechol (g) Water (ml) Observations 1 50 350 60
100 .smallcircle. 2 100 300 60 100 .smallcircle. 3 150 250 60 100
.circle-w/dot. 4 200 200 60 100 .circle-w/dot. 5 250 150 60 100
.circleincircle. 6 300 100 60 100 .smallcircle. 7 350 50 60 100
.smallcircle. (.smallcircle.: good, .circleincircle.: better,
.circle-w/dot.: best)
[0097] The good state is the state similar to using the
conventional resist removing composition EKC-245, the better state
is the improved state compared to the conventional case, and the
best state is the significantly improved state compared to the
conventional case, respectively. EKC-245 is a conventional resist
removing composition having hydroxylamine, diglycolamine, catechol
and water as its essential components.
EXAMPLE V
Analysis of Components of Composition
[0098] The respective components were mixed in a ratio demonstrated
in Table 3 and then the amounts of components of the respective
compositions were analyzed after a predetermined time has elapsed.
The analysis results showed that the respective compositions
include components listed in Table 4.
4TABLE 4 Component Composition Methoxy N hydroxyethyl propanamine
Monoethanolamine Catechol Water Item (weight %) (weight %) (weight
%) (weight %) 1 71.9 0.1 13 15 2 67 5 13 15 3 62 10 13 15 4 55 17
13 15 5 47 25 13 15 6 42 30 13 15 7 32 40 13 15
EXAMPLE VI
Evaluation of Appropriate Processing Time
[0099] To verify appropriate processing time, the composition
corresponding to item number 4 shown in Table 4 was used, and the
resist was removed at different processing times as listed in Table
5. The other processing conditions were the same as those in
Example IV. The removal state of the resist and the attacked states
of an aluminum layer and a silicon layer were observed using
SEM.
5TABLE 5 Resist Removing Performance By Time Processing time
Observations of resist Item (min) removing capability Attacked or
not (Al, Si) 1 10 .circleincircle. x 2 15 .circle-w/dot. x 3 20
.circle-w/dot. x 4 25 .circle-w/dot. x 5 30 .circle-w/dot. x
(.circleincircle.: better, .circle-w/dot.: best)
[0100] The symbols in Table 5 representing the observed removal
state are the same as those in Table 3. In Table 5, an "x"
indicates that the underlying layer is not attacked.
[0101] From the result shown in Table 5, it was observed that the
most appropriate reaction time for removing the resist includes
times from 10 to 30 minutes and that the underlying layer is not
attacked at all.
EXAMPLE VII
Evaluation of Appropriate Processing Temperature
[0102] To verify appropriate processing temperature, the
composition corresponding to item number 4 shown in Table 4 was
used, and the resist was removed at different processing
temperatures as listed in Table 6. The other processing conditions
were the same as those in Example IV. The removal state of the
resist and the attacked states of an aluminum layer and a silicon
layer were observed using SEM.
6TABLE 6 Resist Removing Performance By Temperature Processing
Observations of resist Attacked or not Item temperature (.degree.
C.) removing capability (Al, Si) 1 45 .circle-w/dot. x 2 50
.circle-w/dot. x 3 55 .circle-w/dot. x 4 60 .circle-w/dot. x 5 65
.circle-w/dot. x 5 70 .circle-w/dot. x
[0103] The symbols in Table 6 are the same as those in Table 5.
From the result shown in Table 6, it was observed that the resist
removal occurred rapidly in the lower temperature range from about
45.degree. C. to about 70.degree. C.
EXAMPLE VIII
Comparison of Resist Removing Capability
[0104] The via hole was formed using the resist pattern in the same
manner as that of Example IV, the resist was removed with the
composition corresponding to item number 4 shown in Table 4, the
processing time was 20 minutes, and the reaction temperature was
60.degree. C. The resultant material was observed using SEM, and
the observation results are shown in FIG. 5.
[0105] In a comparative example, the resist was removed using the
conventional resist removing composition EKC-245, with other
conditions being the same as those in the above described examples,
and then the resultant material was observed using SEM. The
observation results are shown in FIG. 6.
[0106] When the SEM photographs shown in FIGS. 5 and 6 are
compared, one can see the resist was completely removed when the
resist removing composition according to the present invention was
used, while the resist partially remains when the conventional
resist removing composition, e.g., EKC-245, was used. Also,
although the underlying aluminum layer was not attacked in the
present invention, the aluminum layer was attacked partially in the
case of using EKC-245.
EXAMPLE IX
Measurement of the Effect of Attack on Copper Layer
[0107] As shown in FIG. 7, to ascertain the effect of attack on a
copper layer to which much attention has been paid as a next
generation interconnection layer, first, a BPSG layer 1200 was
formed on each of a plurality of substrates 1100 to a thickness of
5000 .ANG., and then the BPSG layer of each substrate was patterned
using photolithography to form a plurality of contact holes.
Subsequently, titanium/titanium nitride layers 1300 and 1350,
functioning as a barrier metal layer, were sequentially formed on
the surface of the contact holes to a thickness of 200 .ANG.,
respectively, and then a copper layer 1400 filling the respective
contact holes was formed to a thickness of 10000 .ANG..
[0108] Then, the plurality of substrates were divided into three
groups A, B and C. Group A was not treated with any resist removing
composition, group B was dipped in a resist removing composition
corresponding to item number 4 shown in Table 4 at 65.degree. C.
for 100 minutes, and group C was dipped in a conventional resist
removing composition (EKC-245) at 65.degree. C. for 100
minutes.
[0109] Continuously, some substrates of each group were observed
using SEM. FIG. 7 shows the case when a substrate was not treated
with a resist removing composition (group A), and FIG. 8 shows the
case when a substrate was treated with a resist removing
composition according to the present invention (group B). In the
case of using the resist removing composition according to the
present invention, the same result as in the case of not treating
the substrate with a resist removing composition was achieved,
which is the desired result. In other words, it was ascertained
that the resist removing composition according to the present
invention did not attack the copper layer at all. However, in the
case of using a conventional resist removing composition (group C),
as shown in FIG. 9, the copper layer was attacked so severely that
the copper layer was almost completely removed. From the results
shown in FIGS. 7 through 9, etch rates of the copper layer can be
calculated. The calculated etch rates are listed in the following
Table 7.
7TABLE 7 Etch Rate of Copper Layer Group A B C Etch rate
(.ANG./min) 0 0 >1000
[0110] To ascertain the effect of the resist removing composition
according to the present invention on the surface of the copper
layer, the surface of a copper layer of group A (without treatment
of a resist removing composition) and the surface of a copper layer
of group B (with treatment of the resist removing composition
according to the present invention) were analyzed by Auger Electron
Spectroscopy, and the analysis results are shown in FIGS. 10 and
11, respectively. As shown in FIGS. 10 and 11, the resist removing
composition according to the present invention did not exhibit any
effects on the copper layer, since the Auger electron spectra shown
in FIGS. 10 and 11 were substantially the same.
EXAMPLE X
Analysis of Components of Resist Removing Composition
[0111] The amount of components of the resist removing composition
corresponding to item number 4 shown in Table 4 were analyzed by
gas chromatography at 8 hour intervals. The analysis results are
shown in FIG. 12, in which -.box-solid.- is the area % of amide,
-.DELTA.- is the area % of monoethanolamine, and -x- is the area %
of methyl methoxy propanoate, respectively. From the results shown
in FIG. 12, it was observed that the area % of amide was constant
at about 80% even after 48 hours had elapsed. Also, the area % of
monoethanolamine was constant at 3.4. The area % of methyl methoxy
propanoate was reduced from 0.9 to 0.5 after 24 hours elapsed,
until it became essentially 0 after 40 hours. Also, it was
understood that the composition according to the present invention,
which had undergone the reaction completely and became stabilized,
contained amide, amine, catechol and water. Considering that the
main active component of the composition according to the present
invention is amide, little change in the content of the amide even
after 48 hours implies that the composition according to the
present invention is not quickly, consumed in the process and can
be used for a long time. This means that the composition according
to the present invention can enhance the productivity and can
reduce the manufacturing cost significantly, unlike the
conventional resist removing composition EKC-245 which must be
replaced every 24 hours.
[0112] The amide compound according to the present invention has a
capability for removing a resist. Thus, the resist removing agent
having the amide compound or resist removing composition according
to the present invention has an excellent capability for removing a
resist and can effectively remove polymer and organometallic
polymer. Also, the layer underlying the resist may not be attacked.
Therefore, when the resist removing agent or resist removing
composition according to the present invention is used, it is not
necessary to perform a pre-removal step for removing the polymer
and a post-removal step for preventing the underlying layer from
being attacked. Thus, the resist removing process can be simplified
and the processing time can be reduced. Also, the temperature
required for removing the resist can be set to a lower temperature.
Further, the resist removing apparatus can be simplified and made
more compact.
[0113] It will be apparent to those skilled in the art that various
modifications and variations of the present invention can be made
without departing from the spirit or scope of the invention. Thus,
it is intended that the present invention cover the modifications
and variations of this invention provided they come within the
scope of the appended claims and their equivalents.
* * * * *