U.S. patent application number 14/746115 was filed with the patent office on 2015-10-29 for aqueous cleaner for the removal of post-etch residues.
The applicant listed for this patent is ADVANCED TECHNOLOGY MATERIALS, INC.. Invention is credited to Jeffrey A. Barnes, Steven Lippy, Rekha Rajaram, Peng Zhang.
Application Number | 20150307818 14/746115 |
Document ID | / |
Family ID | 45470097 |
Filed Date | 2015-10-29 |
United States Patent
Application |
20150307818 |
Kind Code |
A1 |
Barnes; Jeffrey A. ; et
al. |
October 29, 2015 |
AQUEOUS CLEANER FOR THE REMOVAL OF POST-ETCH RESIDUES
Abstract
Cleaning compositions and processes for cleaning post-plasma
etch residue from a microelectronic device having said residue
thereon. The composition achieves highly efficacious cleaning of
the residue material, including titanium-containing,
copper-containing, tungsten-containing, and/or cobalt-containing
post-etch residue from the microelectronic device while
simultaneously not damaging the interlevel dielectric, metal
interconnect material, and/or capping layers also present
thereon.
Inventors: |
Barnes; Jeffrey A.;
(Bethlehem, CT) ; Lippy; Steven; (Brookfield,
CT) ; Zhang; Peng; (Montvale, NJ) ; Rajaram;
Rekha; (Scarsdale, NY) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
ADVANCED TECHNOLOGY MATERIALS, INC. |
Danbury |
CT |
US |
|
|
Family ID: |
45470097 |
Appl. No.: |
14/746115 |
Filed: |
June 22, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13810060 |
Jul 29, 2013 |
9063431 |
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PCT/US2011/044191 |
Jul 15, 2011 |
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14746115 |
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61365034 |
Jul 16, 2010 |
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Current U.S.
Class: |
510/175 |
Current CPC
Class: |
H01L 21/02071 20130101;
H01L 21/02063 20130101; C11D 11/0041 20130101; C11D 3/042 20130101;
G03F 7/42 20130101 |
International
Class: |
C11D 11/00 20060101
C11D011/00; C11D 3/04 20060101 C11D003/04 |
Claims
1. An aqueous cleaning composition, comprising at least one
corrosion inhibitor, water, optionally at least one chelating
agent, optionally at least one etchant, optionally at least one
passivating agent, and optionally at least one complexing agent,
wherein said aqueous cleaning composition is suitable for cleaning
post-plasma etch residue from a microelectronic device having said
residue thereon.
2. (canceled)
3. The cleaning composition of claim 1, comprising the at least one
etchant.
4. The cleaning composition of claim 3, wherein the at least one
etchant comprises a fluoride species selected from the group
consisting of hydrofluoric acid, fluoroboric acid,
tetramethylammonium hexafluorophosphate, ammonium fluoride salts,
ammonium bifluoride salts, tetrabutylammonium tetrafluoroborate,
tetramethylammonium tetrafluoroborate, tetraethylammonium
tetrafluoroborate, tetrapropylammonium tetrafluoroborate,
tetrabutylammonium tetrafluoroborate, propylene glycol/HF,
propylene glycol/tetraalkylammonium fluoride, propylene
glycol/benzyltrimethylammonium fluoride, and combinations
thereof.
5. The cleaning composition of claim 3, wherein the at least one
etchant comprises a fluoride selected from the group consisting of
ammonium bifluoride, tetrabutylammonium tetrafluoroborate, and
combinations thereof.
6. The cleaning composition of claim 1, comprising the at least one
passivating agent, wherein the at least one passivating agent
comprises a species selected from the group consisting of boric
acid, 3-hydroxy-2-naphthoic acid, malonic acid, iminodiacetic acid,
and mixtures thereof.
7. The cleaning composition of claim 3, wherein the at least one
etchant comprises a quaternary phosphonium tetrafluoroborate having
the formula PR.sub.4BF.sub.4, wherein R may be the same as or
different from one another and is selected from the group
consisting of hydrogen, straight-chained C.sub.1-C.sub.6 alkyl,
branched C.sub.1-C.sub.6 alkyl, or cyclic C.sub.1-C.sub.6 alkyl,
straight-chained C.sub.6-C.sub.10 aryl, and branched
C.sub.6-C.sub.10 aryl.
8. The cleaning composition of claim 6, wherein the at least one
passivating agent comprises boric acid.
9. The cleaning composition of claim 1, wherein the at least one
metal corrosion inhibitor comprises a species selected from the
group consisting of benzotriazole (BTA), 1,2,4-triazole (TAZ),
5-aminotetrazole (ATA), 1-hydroxybenzotriazole,
5-amino-1,3,4-thiadiazol-2-thiol, 3-amino-1H-1,2,4 triazole,
3,5-diamino-1,2,4-triazole, tolyltriazole, 5-phenyl-benzotriazole,
5-nitro-benzotriazole, 3-amino-5-mercapto-1,2,4-triazole,
1-amino-1,2,4-triazole, 2-(5-amino-pentyl)-benzotriazole,
1-amino-1,2,3-triazole, 1-amino-5-methyl-1,2,3-triazole,
3-mercapto-1,2,4-triazole, 3-isopropyl-1,2,4-triazole,
5-phenylthiol-benzotriazole, halo-benzotriazoles (halo=F, Cl, Br,
I), naphthotriazole, 1H-tetrazole-5-acetic acid,
2-mercaptobenzothiazole (2-MBT), 1-phenyl-2-tetrazoline-5-thione,
2-mercaptobenzimidazole (2-MBI), 4-methyl-2-phenylimidazole,
2-mercaptothiazoline, 2,4-diamino-6-methyl-1,3,5-triazine,
thiazole, imidazole, benzimidazole, triazine, methyltetrazole,
Bismuthiol I, 1,3-dimethyl-2-imidazolidinone,
1,5-pentamethylenetetrazole, 1-phenyl-5-mercaptotetrazole,
diaminomethyltriazine, imidazoline thione,
4-methyl-4H-1,2,4-triazole-3-thiol,
5-amino-1,3,4-thiadiazole-2-thiol, benzothiazole, tritolyl
phosphate, indazole, adenine, cytosine, guanine, thymine, phosphate
inhibitors, amines, pyrazoles, propanethiol, silanes, secondary
amines, benzohydroxamic acids, heterocyclic nitrogen inhibitors,
citric acid, ascorbic acid, thiourea, 1,1,3,3-tetramethylurea,
urea, urea derivatives, uric acid, potassium ethylxanthate,
glycine, dodecylphosphonic acid, iminodiacetic acid, acid, boric
acid, malonic acid, succinic acid, nitrilotriacetic acid,
sulfolane, 2,3,5-trimethylpyrazine, 2-ethyl-3,5-dimethylpyrazine,
quinoxaline, acetyl pyrrole, pyridazine, histadine, pyrazine,
glutathione (reduced), cysteine, cystine, thiophene, mercapto
pyridine N-oxide, thiamine HCl, tetraethyl thiuram disulfide,
2,5-dimercapto-1,3-thiadiazoleascorbic acid, ascorbic acid, and
combinations thereof.
10. The cleaning composition of claim 1, comprising the at least
one complexing agent, wherein the at least one complexing agent
comprises a species selected from the group consisting of
butylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid
(DTPA), ethylenediaminetetrapropionic acid,
(hydroxyethyl)ethylenediaminetriacetic acid (HEDTA),
N,N,N',N'-ethylenediaminetetra(methylenephosphonic) acid (EDTMP),
triethylenetetraminehexaacetic acid (TTHA),
1,3-diamino-2-hydroxypropane-N,N,N',N'-tetraacetic acid (DHPTA),
methyliminodiacetic acid, propylenediaminetetraacetic acid,
1,5,9-triazacyclododecane-N,N',N''-tris(methylenephosphonic acid)
(DOTRP),
1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetrakis(methylenep-
hosphonic acid) (DOTP), nitrilotris(methylene)triphosphonic acid,
diethylenetriaminepenta(methylenephosphonic acid) (DETAP),
aminotri(methylenephosphonic acid),
1-hydroxyethylidene-1,1-diphosphonic acid (HEDP),
bis(hexamethylene)triamine phosphonic acid,
1,4,7-triazacyclononane-N,N',N''-tris(methylenephosphonic acid
(NOTP), 2-phosphonobutane-1,2,4-tricarboxylic acid, tartaric acid,
gluconic acid, saccharic acid, glyceric acid, phthalic acid, maleic
acid, mandelic acid, lactic acid, dihydroxybenzoic acid, catechol,
gallic acid, propyl gallate, pyrogallol, cysteine,
dihydroxysalicylic acid, glyphosphate,
N-(Phosphonomethyl)-iminodiacetic acid, formic acid, propanoic
acid, butanoic acid, N-(2-Hydroxyethyl)-iminodiacetic acid,
pyridine-2,5-dicarboxylic acid, pyridine-2,6-dicarboxylic acid,
7-Iodo-8-hydroxyquinoline-5-sulfonic acid,
2-amino-2-propylphosphonic acid, 1,2-dihydroxybenzene-4-sulfonic
acid, 4,5-dihydroxy-1,3-benzene disulfonic acid (Tiron), solochrome
violet R, 3-hydroxy-2-naphthoic acid, chromotropic acid,
nitroacetic acid, oxydiacetic acid, thiodiacetic acid,
8-hydroxy-7-(arylazo)-quinoline-5-sulfonic acid, 2-oxobutanoic
acid, acetoacetic acid, phenylserine, squaric acid, acetohydroxamic
acid, 3-hydroxy-5,7-disulfo-2-naphthoic acid,
2,3-dihydroxynaphthalene-6-sulfonic acid, sulfoxine, oxine,
3,4-dihydroxybenzoic acid,
2-(3,4-dihydroxyphenyl)-2-(1,1-benzopyran)-3,5,7-triol,
3-hydroxy-7-sulfo-2-naphthoic acid,
1,2-dihydroxynaphthalene-4-sulfonic acid,
N,N-bis(2-hydroxyethyl)glycine, N-(phosphonomethyl)-iminodiacetic
acid, iminobis(methylenephosphonic acid),
1-oxopropane-1,2-dicarboxylic acid, propane-1,2,3-tricarboxylic
acid,
N,N',N''-tris[2-(N-hydroxycarbamoyl)ethyl]-1,3,5-benzenetricarboxamide
(BAMTPH), desferriferrioxamine-B,
1,7-dihydroxy-4-sulfo-2-naphthanoic acid, aspartic acid, glutamic
acid, pyridoxal-5-(dihydrogenphosphate), pyridoxal,
amino(phenyl)methylene-diphosphoric acid, ethylene glycol
tetraacetic acid (EGTA),
ethylenebis(imino-(2-hydroxyphenyl)methylene(methyl)-phosphonic
acid)), N-(2-hydroxyethyl)-ethylenedinitrilo-N,N',N'-triacetic
acid, trimethylenedinitrilotetracetic acid,
(2-dihydroxytrimethylene)-dinitrilotetracetic acid, xylenol orange,
methylthymol blue, 3-hydroxyglutamic acid, L-phosphoserine,
DL-amino-3-phosphopropanoic acid, and combinations thereof.
11. The cleaning composition of claim 1, wherein the amount of
water is in a range from about 50 wt % to about 99 wt %, based on
the total weight of the composition.
12. The cleaning composition of claim 1, wherein the pH is in a
range from about 0 to about 7.
13. The cleaning composition of claim 1, wherein the composition is
substantially devoid of abrasive material, oxidizing agents,
ammonia, strong bases, and amidoxime complexing agents.
14. The cleaning composition of claim 1, further comprising at
least one organic solvent.
15. The cleaning composition of claim 1, further comprising a
source of silica.
16. The cleaning composition of claim 1, wherein said composition
further comprises post-plasma etch residue selected from the group
consisting of titanium-containing residue, polymeric-residue,
copper-containing residue, tungsten-containing residue,
cobalt-containing residue, and combinations thereof.
17. (canceled)
18. A method of removing material from a microelectronic device
having said material thereon, said method comprising contacting the
microelectronic device with an aqueous cleaning composition for
sufficient time to at least partially remove said material from the
microelectronic device, wherein the aqueous cleaning composition
includes at least one corrosion inhibitor, water, optionally at
least one chelating agent, optionally at least one etchant,
optionally at least one passivating agent, and optionally at least
one complexing agent.
19. The method of claim 17, wherein the material comprises
post-plasma etch residue comprising residue selected from the group
consisting of titanium-containing compounds, polymeric compounds,
copper-containing compounds, tungsten-containing compounds,
cobalt-containing compounds, and combinations thereof.
20. The method of claim 17, wherein said contacting comprises
conditions selected from the group consisting of: time of from
about 1 minute to about 30 minutes; temperature in a range of from
about 40.degree. C. to about 70.degree. C.; and combinations
thereof.
Description
FIELD
[0001] The present invention relates to compositions for the
removal of post-etch residue, including titanium-containing,
copper-containing and/or tungsten-containing post-etch residue,
from microelectronic devices and methods of making and using the
same.
DESCRIPTION OF THE RELATED ART
[0002] Interconnect circuitry in semiconductor circuits consists of
conductive metallic circuitry surrounded by insulating dielectric
material. In the past, silicate glass vapor-deposited from
tetraethylorthosilicate (TEOS) was widely used as the dielectric
material, while alloys of aluminum were used for metallic
interconnects. Demand for higher processing speeds has led to
smaller sizing of circuit elements, along with the replacement of
TEOS and aluminum alloys by higher performance materials. Aluminum
alloys have been replaced by copper or copper alloys due to the
higher conductivity of copper. TEOS and fluorinated silicate glass
(FSG) have been replaced by the so-called low-k dielectrics,
including low-polarity materials such as organic polymers, hybrid
organic/inorganic materials, organosilicate glass (OSG), and
carbon-doped oxide (CDO) glass. The incorporation of porosity,
i.e., air-filled pores, in these materials further lowers the
dielectric constant of the material.
[0003] During dual-damascene processing of integrated circuits,
photolithography is used to image a pattern onto a device wafer.
Photolithography techniques comprise the steps of coating,
exposure, and development. A wafer is coated with a positive or
negative photoresist substance and subsequently covered with a mask
that defines patterns to be retained or removed in subsequent
processes. Following the proper positioning of the mask, the mask
has directed therethrough a beam of monochromatic radiation, such
as ultraviolet (UV) light or deep UV (DUV) light (.apprxeq.250 nm
or 193 nm), to make the exposed photoresist material more or less
soluble in a selected rinsing solution. The soluble photoresist
material is then removed, or "developed," leaving behind a pattern
identical to the mask.
[0004] Thereafter, gas-phase plasma etching is used to transfer the
patterns of the developed photoresist coating to the underlying
layers, which may include hardmask, interlevel dielectric (ILD),
and/or etch stop layers. Post-plasma etch residues are typically
deposited on the back-end-of-the-line (BEOL) structures and if not
removed, may interfere with subsequent silicidation or contact
formation. Post-plasma etch residues typically include chemical
elements present on the substrate and in the plasma gases. For
example, if a TiN hardmask is employed, e.g., as a capping layer
over ILD, the post-plasma etch residues include titanium-containing
species, which are difficult to remove using conventional wet
cleaning chemistries. Moreover, conventional cleaning chemistries
often damage the ILD, absorb into the pores of the ILD thereby
increasing the dielectric constant, and/or corrode the metal
structures. For example, buffered fluoride and solvent-based
chemistries fail to completely remove Ti-containing residues, while
hydroxylamine-containing and ammonia-peroxide chemistries corrode
copper.
[0005] In addition to the desirable removal of titanium-containing
post-plasma etch residue, additional materials that are deposited
during the post-plasma etch process such as polymeric residues on
the sidewalls of the patterned device, copper-containing residues
in the open via structures of the device, and tungsten-containing
residues are also preferably removed. To date, no single wet
cleaning composition has successfully removed all of residue
material while simultaneously being compatible with the ILD, other
low-k dielectric materials, and metal interconnect materials.
[0006] The integration of new materials, such as low-k dielectrics,
into microelectronic devices places new demands on cleaning
performance. At the same time, shrinking device dimensions reduce
the tolerance for changes in critical dimensions and damage to
device elements. Etching conditions can be modified in order to
meet the demands of the new materials. Likewise, post-plasma etch
cleaning compositions must be modified. The cleaner should not
damage the underlying dielectric material or corrode metallic
interconnect materials, e.g., copper, tungsten, cobalt, aluminum,
ruthenium, titanium and nitrides and silicides thereof, on the
device.
[0007] Towards that end, it is an object of the present invention
to provide improved compositions for the effective removal of
post-plasma etch residue including, but not limited to,
titanium-containing residue, polymeric sidewall residue,
copper-containing via residue, tungsten-containing residue, and/or
cobalt-containing residue from microelectronic devices, said
compositions being compatible with ILD, metal interconnect
materials, and/or capping layers.
SUMMARY
[0008] The present invention generally relates to cleaning
compositions and methods of making and using same. One aspect of
the invention relates to a composition and process for cleaning
post-plasma etch residue from microelectronic devices having said
residue thereon, while simultaneously not compromising the metallic
and ILD materials on the microelectronic device surface.
[0009] In one aspect, an aqueous cleaning composition is described,
said composition comprising at least one corrosion inhibitor,
water, optionally at least one chelating agent, optionally at least
one etchant, optionally at least one passivating agent, and
optionally at least one complexing agent. The aqueous cleaning
composition is suitable for cleaning post-plasma etch residue from
a microelectronic device having said residue thereon.
[0010] In another aspect, an aqueous cleaning composition is
described, said composition comprising at least one corrosion
inhibitor, water, at least one etchant, at least one passivating
agent, optionally at least one chelating agent, and optionally at
least one complexing agent. The aqueous cleaning composition is
suitable for cleaning post-plasma etch residue from a
microelectronic device having said residue thereon.
[0011] In yet another aspect, a kit is described, said kit
comprising, in one or more containers, one or more of the following
reagents for forming an aqueous cleaning composition, said one or
more reagents selected from the group consisting of at least one
corrosion inhibitor, water, optionally at least one chelating
agent, optionally at least one etchant, optionally at least one
passivating agent, and optionally at least one complexing agent and
wherein the kit is adapted to form an aqueous cleaning composition
suitable for cleaning post-plasma etch residue from a
microelectronic device having said residue thereon.
[0012] In still another aspect, a method of removing material from
a microelectronic device having said material thereon is described,
said method comprising contacting the microelectronic device with
an aqueous cleaning composition for sufficient time to at least
partially remove said material from the microelectronic device,
wherein the aqueous cleaning composition includes at least one
corrosion inhibitor, water, optionally at least one chelating
agent, optionally at least one etchant, optionally at least one
passivating agent, and optionally at least one complexing
agent.
[0013] In another aspect, a method of removing material from a
microelectronic device having said material thereon is described,
said method comprising contacting the microelectronic device with
an aqueous cleaning composition for sufficient time to at least
partially remove said material from the microelectronic device,
wherein the aqueous cleaning composition includes at least one
corrosion inhibitor, water, at least one etchant, at least one
passivating agent, optionally at least one chelating agent, and
optionally at least one complexing agent.
[0014] Other aspects, features and advantages of the invention will
be more fully apparent from the ensuing disclosure and appended
claims.
DETAILED DESCRIPTION, AND PREFERRED EMBODIMENTS THEREOF
[0015] The present invention generally relates to compositions for
removing residue, preferably post-etch residue, more preferably
titanium-containing post-etch residue, polymeric sidewall residue,
copper-containing via and line residue and/or tungsten-containing
post-etch residue from microelectronic devices having said residue
thereon, said compositions preferably being compatible with ultra
low-k (ULK) ILD materials, such as OSG and porous-CDO, the metallic
interconnect materials, e.g., copper and tungsten, the hardmask
capping layers, e.g., TiN, and cobalt capping layers, e.g., CoWP,
on the microelectronic device surface. Further, the present
invention generally relates to methods of removing residue,
preferably post-etch residue, more preferably titanium-containing
post-etch residue, polymeric sidewall residue, copper-containing
via and line residue, tungsten-containing post-etch residue, and/or
cobalt-containing post-etch residue, from microelectronic devices
having said residue thereon, using compositions, said compositions
preferably being compatible with ultra low-k (ULK) ILD materials,
the metallic interconnect materials, and the capping layers, on the
microelectronic device surface.
[0016] For ease of reference, "microelectronic device" corresponds
to semiconductor substrates, flat panel displays, phase change
memory devices, solar panels and other products including solar
cell devices, photovoltaics, and microelectromechanical systems
(MEMS), manufactured for use in microelectronic, integrated
circuit, energy collection, or computer chip applications. It is to
be understood that the term "microelectronic device" is not meant
to be limiting in any way and includes any substrate or structure
that will eventually become a microelectronic device or
microelectronic assembly. Notably, the microelectronic device
substrate may be patterned, blanketed and/or a test substrate.
[0017] "Post-etch residue" and "post-plasma etch residue," as used
herein, corresponds to material remaining following gas-phase
plasma etching processes, e.g., BEOL dual-damascene processing. The
post-etch residue may be organic, organometallic, organosilicic, or
inorganic in nature, for example, silicon-containing material,
titanium-containing material, nitrogen-containing material,
oxygen-containing material, polymeric residue material,
copper-containing residue material (including copper oxide
residue), tungsten-containing residue material, cobalt-containing
residue material, etch gas residue such as chlorine and fluorine,
and combinations thereof.
[0018] As defined herein, "low-k dielectric material" and ULK
corresponds to any material used as a dielectric material in a
layered microelectronic device, wherein the material has a
dielectric constant less than about 3.5. Preferably, the low-k
dielectric materials include low-polarity materials such as
silicon-containing organic polymers, silicon-containing hybrid
organic/inorganic materials, organosilicate glass (OSG), TEOS,
fluorinated silicate glass (FSG), silicon dioxide, and carbon-doped
oxide (CDO) glass. Most preferably, the low-k dielectric material
is deposited using organosilane and/or organosiloxane precursors.
It is to be appreciated that the low-k dielectric materials may
have varying densities and varying porosities.
[0019] As defined herein, the term "polymeric sidewall residue"
corresponds to the residue that remains on the sidewalls of the
patterned device subsequent to post-plasma etching processes. The
residue is substantially polymeric in nature however, it should be
appreciated that inorganic species, e.g., titanium, silicon,
tungsten, cobalt and/or copper-containing species, may be present
in the sidewall residue as well.
[0020] As used herein, "about" is intended to correspond to .+-.5%
of the stated value.
[0021] As used herein, "suitability" for cleaning post-etch residue
from a microelectronic device having said residue thereon
corresponds to at least partial removal of said residue from the
microelectronic device. Preferably, at least about 90% of one or
more of the materials, more preferably at least 95% of one or more
of the materials, and most preferably at least 99% of one or more
of the materials to be removed are removed from the microelectronic
device.
[0022] "Capping layer" as used herein corresponds to materials
deposited over dielectric material and/or metal material, e.g.,
cobalt, to protect same during the plasma etch step. Hardmask
capping layers are traditionally silicon, silicon nitrides, silicon
oxynitrides, titanium nitride, titanium oxynitride, titanium,
tantalum, tantalum nitride, molybdenum, tungsten, combinations
thereof, and other similar compounds. Cobalt capping layers include
CoWP and other cobalt-containing materials or tungsten-containing
materials.
[0023] "Substantially devoid" is defined herein as less than 2 wt.
%, preferably less than 1 wt. %, more preferably less than 0.5 wt.
%, and most preferably less than 0.1 wt. %.
[0024] As used herein, the term "semi-aqueous" refers to a mixture
of water and organic components.
[0025] As defined herein, "complexing agent" includes those
compounds that are understood by one skilled in the art to be
complexing agents, chelating agents, sequestering agents, and
combinations thereof. Complexing agents will chemically combine
with or physically hold the metal atom and/or metal ion to be
removed using the compositions described herein.
[0026] As defined herein, a "strong base" includes alkali and
alkaline earth metal hydroxide salts such as LiOH, NaOH, KOH, RbOH,
CsOH, Mg(OH).sub.2, Ca(OH).sub.2, Sr(OH).sub.2 and Ba(OH).sub.2, as
well as quaternary ammonium hydroxides having the formula
NR.sup.1R.sup.2R.sup.3R.sup.4OH, where R.sup.1, R.sup.2, R.sup.3
and R.sup.4 are the same as or different from one another and are
selected from the group consisting of C.sub.1-C.sub.6 alkyls,
C.sub.6-C.sub.10 aryls, and combinations thereof.
[0027] Compositions of the invention may be embodied in a wide
variety of specific formulations, as hereinafter more fully
described.
[0028] In all such compositions, wherein specific components of the
composition are discussed in reference to weight percentage ranges
including a zero lower limit, it will be understood that such
components may be present or absent in various specific embodiments
of the composition, and that in instances where such components are
present, they may be present at concentrations as low as 0.001
weight percent, based on the total weight of the composition in
which such components are employed.
[0029] Titanium-containing post-etch residue materials are
notoriously difficult to remove using the ammonia-containing
compositions of the prior art. The present inventors discovered a
cleaning composition that is substantially devoid of ammonia and/or
strong bases (e.g., NaOH, KOH, etc.) and preferably, substantially
devoid of oxidizing agents, which effectively and selectively
removes titanium-containing residues from the surface of a
microelectronic device having same thereon. In addition, the
composition will substantially remove polymeric sidewall residue,
copper-containing residue, cobalt-containing residue, and/or
tungsten-containing residue without substantially damaging the
underlying ILD, metal interconnect materials, e.g., Cu, Al, Co and
W, and/or the capping layers. Further, the compositions may be used
regardless of whether the trench or via is etched first (i.e., a
trench-first or via-first scheme). Further, the composition can be
formulated to substantially remove TiN layers from the surface of a
microelectronic device having same thereon.
[0030] In a first aspect, the cleaning compositions described
herein are aqueous or semi-aqueous and include at least one
corrosion inhibitor, water, optionally at least one etchant source,
optionally at least one metal-chelating agent, optionally at least
one complexing agent, and optionally at least one passivating
agent, for removing post-plasma etch residues from the surface of a
microelectronic device having same thereon, wherein the post-plasma
etch residue comprises a species selected from the group consisting
of titanium-containing residues, polymeric residues,
copper-containing residues, tungsten-containing residues,
cobalt-containing residues, and combinations thereof. In another
embodiment, the cleaning compositions described herein include at
least one corrosion inhibitor, water, at least one etchant source,
optionally at least one metal-chelating agent, optionally at least
one complexing agent, and optionally at least one passivating
agent. In still another embodiment, the cleaning compositions
include at least one corrosion inhibitor, water, at least one
metal-chelating agent, optionally at least one etchant source,
optionally at least one complexing agent, and optionally at least
one passivating agent. In still another embodiment, the cleaning
compositions include at least one corrosion inhibitor, water, at
least one complexing agent, optionally at least one etchant source,
optionally at least one passivating agent, and optionally at least
one metal-chelating agent. In another embodiment, the cleaning
compositions include at least one corrosion inhibitor, water, at
least one passivating agent, optionally at least one
metal-chelating agent, optionally at least one complexing agent,
and optionally at least one etchant source. In another embodiment,
the cleaning compositions include at least one corrosion inhibitor,
water, at least one etchant source, at least one metal-chelating
agent, optionally at least one passivating agent, and optionally at
least one complexing agent. In yet another embodiment, the cleaning
compositions include at least one corrosion inhibitor, water, at
least one etchant source, at least one complexing agent, optionally
at least one passivating agent, and optionally at least one
metal-chelating agent. In another embodiment, the cleaning
compositions include at least one corrosion inhibitor, water, at
least one complexing agent, at least one metal-chelating agent,
optionally at least one passivating agent, and optionally at least
one etchant source. In another embodiment, the cleaning
compositions include at least one corrosion inhibitor, water, at
least one etchant source, at least one passivating agent,
optionally at least one complexing agent, and optionally at least
one metal-chelating agent. In still another embodiment, the
cleaning compositions include at least one corrosion inhibitor,
water, at least one complexing agent, at least one metal-chelating
agent, and at least one etchant source. Preferably, the amount of
water present is in a range from about 50 wt % to about 99 wt %,
based on the total weight of the composition. In each embodiment,
at least one surfactant, a source of silica, and/or at least one
organic solvent may be added.
[0031] In one embodiment, the aqueous composition for cleaning
post-plasma etch residues selected from the group consisting of
titanium-containing residues, polymeric residues, copper-containing
residues, tungsten-containing residues, cobalt-containing residues,
and combinations thereof, includes at least one corrosion
inhibitor, water, optionally at least one etchant, optionally at
least one metal chelating agent, optionally at least one
passivating agent, and optionally at least one complexing agent,
present in the following ranges, based on the total weight of the
composition.
TABLE-US-00001 component % by weight corrosion inhibitor(s) about
0.01% to about 20% water about 50% to about 97% etchant source(s)
0% to about 50 wt. % chelating agent(s) 0% to about 10% passivating
agent(s) 0 to about 5% complexing agent(s) 0 to about 10%
surfactant(s) 0 to about 10% organic solvent(s) 0 to about 10%
[0032] In the broad practice, the cleaning composition may
comprise, consist of, or consist essentially of: (i) at least one
corrosion inhibitor, water, optionally at least one etchant source,
optionally at least one metal-chelating agent, optionally at least
one passivating agent, and optionally at least one complexing
agent; (ii) at least one corrosion inhibitor, water, at least one
etchant source, optionally at least one metal-chelating agent,
optionally at least one passivating agent, and optionally at least
one complexing agent; (iii) at least one corrosion inhibitor,
water, at least one metal-chelating agent, optionally at least one
etchant source, optionally at least one passivating agent, and
optionally at least one complexing agent; (iv) at least one
corrosion inhibitor, water, at least one complexing agent,
optionally at least one etchant source, optionally at least one
passivating agent, and optionally at least one metal-chelating
agent; (v) at least one corrosion inhibitor, water, at least one
etchant source, at least one metal-chelating agent, optionally at
least one passivating agent and optionally at least one complexing
agent; (vi) at least one corrosion inhibitor, water, at least one
etchant source, at least one complexing agent, optionally at least
one passivating agent and optionally at least one metal-chelating
agent; (vii) at least one corrosion inhibitor, water, at least one
complexing agent, at least one metal-chelating agent, optionally at
least one passivating agent and optionally at least one etchant
source; (viii) at least one corrosion inhibitor, water, at least
one complexing agent, at least one metal-chelating agent, and at
least one etchant source; (ix) at least one corrosion inhibitor,
water, at least one passivating agent, optionally at least one
metal-chelating agent, optionally at least one complexing agent,
and optionally at least one etchant source; (x) at least one
corrosion inhibitor, water, at least one etchant source, at least
one passivating agent, optionally at least one complexing agent,
and optionally at least one metal-chelating agent.
[0033] The water is included to serve as a solvent and assist in
the dissolution of residues, e.g., water-soluble copper oxide
residues. The water is preferably deionized.
[0034] In a preferred embodiment, the aqueous cleaning composition
is substantially devoid of oxidizing agents such as
peroxide-containing compounds and nitric acid. In another preferred
embodiment, the aqueous cleaning composition is substantially
devoid of abrasive material prior to contact with the substrate to
be cleaned.
[0035] The pH range of the aqueous cleaning composition is about 0
to about 7, preferably about 0 to about 5, even more preferably
about 0 to about 4, and most preferably about 0 to about 3.
[0036] The etchant sources assist in breaking up and solubilizing
the post-etch residue species, aiding in polymer sidewall residue
removal and slightly etching of the TiN hardmask. Etchant sources
contemplated herein include, but are not limited to: hydrofluoric
acid (HF); fluorosilicic acid (H.sub.2SiF.sub.6); fluoroboric acid;
ammonium fluorosilicate salt ((NH.sub.4).sub.2SiF.sub.6);
tetramethylammonium hexafluorophosphate; ammonium fluoride salts;
ammonium bifluoride salts; quaternary ammonium tetrafluoroborates
and quaternary phosphonium tetrafluoroborates having the formula
NR.sub.4BF.sub.4 and PR.sub.4BF.sub.4, respectively, wherein R may
be the same as or different from one another and is selected from
the group consisting of hydrogen, straight-chained, branched, or
cyclic C.sub.1-C.sub.6 alkyl (e.g., methyl, ethyl, propyl, butyl,
pentyl, hexyl), and straight-chained or branched C.sub.6-C.sub.10
aryl (e.g., benzyl); tetrabutylammonium tetrafluoroborate
(TBA-BF.sub.4); propylene glycol/HF in a weight ratio of about
90:10 to about 99:1, preferably about 93:7 to about 98:2; propylene
glycol/tetraalkylammonium fluoride, where the alkyl groups may be
the same as or different from one another and are selected from the
group consisting of straight chained or branched C.sub.1-C.sub.6
alkyl groups (e.g., methyl, ethyl, propyl, butyl, pentyl, hexyl),
in a weight ratio of about 75:25 to about 95:5, preferably about
80:20 to about 90:10; propylene glycol/tetrabutylammonium fluoride
in a weight ratio of about 75:25 to about 95:5, preferably about
80:20 to about 90:10; propylene glycol/benzyltrimethylammonium
fluoride in a weight ratio of about 75:25 to about 95:5, preferably
about 80:20 to about 90:10; and combinations thereof. Preferably,
the etchant source comprises ammonium bifluoride, quaternary
ammonium tetrafluoroborates (e.g., tetramethylammonium
tetrafluoroborate, tetraethylammonium tetrafluoroborate,
tetrapropylammonium tetrafluoroborate, tetrabutylammonium
tetrafluoroborate), quaternary phosphonium tetrafluoroborates, or
combinations thereof. Preferably, the etchant source comprises
ammonium bifluoride, tetrabutylammonium tetrafluoroborate, or a
combination thereof. It should be appreciated by the skilled
artisan that quaternary ammonium tetrafluoroborates and quaternary
phosphonium tetrafluoroborates may be generated in situ.
[0037] The organic solvents, when present, assist in solubilization
of the components of the aqueous cleaning composition and organic
residues, wet the surface of the microelectronic device structure
to facilitate residue removal, prevent residue redeposition, and/or
passivate the underlying materials, e.g., ULK. Organic solvents
contemplated herein include, but are not limited to, alcohols,
ethers, pyrrolidinones, glycols, amines, and glycol ethers,
including, but not limited to, methanol, ethanol, isopropanol,
butanol, and higher alcohols (such as C.sub.2-C.sub.4 diols and
C.sub.2-C.sub.4 triols), tetrahydrofurfuryl alcohol (THFA),
halogenated alcohols (such as 3-chloro-1,2-propanediol,
3-chloro-1-propanethiol, 1-chloro-2-propanol, 2-chloro-1-propanol,
3-chloro-1-propanol, 3-bromo-1,2-propanediol, 1-bromo-2-propanol,
3-bromo-1-propanol, 3-iodo-1-propanol, 4-chloro-1-butanol,
2-chloroethanol), dichloromethane, chloroform, acetic acid,
propionic acid, trifluoroacetic acid, tetrahydrofuran (THF),
N-methylpyrrolidinone (NMP), cyclohexylpyrrolidinone,
N-octylpyrrolidinone, N-phenylpyrrolidinone, methyldiethanolamine,
methyl formate, dimethyl formamide (DMF), dimethylsulfoxide (DMSO),
tetramethylene sulfone (sulfolane), diethyl ether,
phenoxy-2-propanol (PPh), propriophenone, ethyl lactate, ethyl
acetate, ethyl benzoate, acetonitrile, acetone, ethylene glycol,
propylene glycol (PG), 1,3-propanediol, 1,4-propanediol, dioxane,
butyryl lactone, butylene carbonate, ethylene carbonate, propylene
carbonate, dipropylene glycol, diethylene glycol monomethyl ether,
triethylene glycol monomethyl ether, diethylene glycol monoethyl
ether, triethylene glycol monoethyl ether, ethylene glycol
monopropyl ether, ethylene glycol monobutyl ether, diethylene
glycol monobutyl ether (i.e., butyl carbitol), triethylene glycol
monobutyl ether, ethylene glycol monohexyl ether, diethylene glycol
monohexyl ether, ethylene glycol phenyl ether, propylene glycol
methyl ether, dipropylene glycol methyl ether (DPGME), tripropylene
glycol methyl ether (TPGME), dipropylene glycol dimethyl ether,
dipropylene glycol ethyl ether, propylene glycol n-propyl ether,
dipropylene glycol n-propyl ether (DPGPE), tripropylene glycol
n-propyl ether, propylene glycol n-butyl ether, dipropylene glycol
n-butyl ether, tripropylene glycol n-butyl ether, propylene glycol
phenyl ether, dipropylene glycol methyl ether acetate, dibasic
ester, glycerine carbonate, N-formyl morpholine, triethyl
phosphate, and combinations thereof. In addition, the organic
solvent may comprise other amphiphilic species, i.e., species that
contain both hydrophilic and hydrophobic moieties similar to
surfactants. Hydrophobic properties may generally be imparted by
inclusion of a molecular group consisting of hydrocarbon or
fluorocarbon groups and the hydrophilic properties may generally be
imparted by inclusion of either ionic or uncharged polar functional
groups. Preferably, the organic solvent includes tripropylene
glycol methyl ether (TPGME), dipropylene glycol methyl ether
(DPGME), propylene glycol, and combinations thereof. When present,
the composition includes at least 0.01 wt % organic solvent, based
on the total weight of the composition.
[0038] The metal corrosion inhibitors serve to eliminate
over-etching of metals, e.g., copper, tungsten, and/or cobalt
interconnect metals. Suitable corrosion inhibitors include, but are
not limited to, azoles such as benzotriazole (BTA), 1,2,4-triazole
(TAZ), 5-aminotetrazole (ATA), 1-hydroxybenzotriazole,
5-amino-1,3,4-thiadiazol-2-thiol, 3-amino-1H-1,2,4 triazole,
3,5-diamino-1,2,4-triazole, tolyltriazole, 5-phenyl-benzotriazole,
5-nitro-benzotriazole, 3-amino-5-mercapto-1,2,4-triazole,
1-amino-1,2,4-triazole, 2-(5-amino-pentyl)-benzotriazole,
1-amino-1,2,3-triazole, 1-amino-5-methyl-1,2,3-triazole,
3-mercapto-1,2,4-triazole, 3-isopropyl-1,2,4-triazole,
5-phenylthiol-benzotriazole, halo-benzotriazoles (halo=F, Cl, Br or
I), naphthotriazole, 1H-tetrazole-5-acetic acid,
2-mercaptobenzothiazole (2-MBT), 1-phenyl-2-tetrazoline-5-thione,
2-mercaptobenzimidazole (2-MBI), 4-methyl-2-phenylimidazole,
2-mercaptothiazoline, 2,4-diamino-6-methyl-1,3,5-triazine,
thiazole, imidazole, benzimidazole, triazine, methyltetrazole,
Bismuthiol I, 1,3-dimethyl-2-imidazolidinone,
1,5-pentamethylenetetrazole, 1-phenyl-5-mercaptotetrazole,
diaminomethyltriazine, imidazoline thione,
4-methyl-4H-1,2,4-triazole-3-thiol,
5-amino-1,3,4-thiadiazole-2-thiol, benzothiazole, tritolyl
phosphate, indazole, DNA bases (e.g., adenine, cytosine, guanine,
thymine), phosphate inhibitors, amines, pyrazoles, iminodiacetic
acid (IDA), propanethiol, silanes, secondary amines,
benzohydroxamic acids, heterocyclic nitrogen inhibitors, citric
acid, ascorbic acid, thiourea, 1,1,3,3-tetramethylurea, urea, urea
derivatives, uric acid, potassium ethylxanthate, glycine,
dodecylphosphonic acid (DDPA), and mixtures thereof. Dicarboxylic
acids such as oxalic acid, malonic acid, succinic acid,
nitrilotriacetic acid, and combinations thereof are also useful
copper passivator species. It is generally accepted that azoles
chemisorb onto the copper surface and form an insoluble cuprous
surface complex. Suitable tungsten corrosion inhibitor include, but
are not limited to, sulfolane, 2-mercaptothiazoline,
2,3,5-trimethylpyrazine, 2-ethyl-3,5-dimethylpyrazine, quinoxaline,
acetyl pyrrole, pyridazine, histidine, pyrazine, glycine,
benzimidazole, benzotriazole (BTA), iminodiacetic acid (IDA),
glutathione (reduced), cysteine, 2-mercaptobenzimidazole, cystine,
thiophene, mercapto pyridine N-oxide, thiamine HCl, tetraethyl
thiuram disulfide, 1,2,4-triazole,
2,5-dimercapto-1,3-thiadiazoleascorbic acid, ascorbic acid, and
combinations thereof, preferably sulfolane, pyrazine, glycine,
histidine, ascorbic acid, and combinations thereof.
[0039] Preferably, the corrosion inhibitor includes BTA, TAZ,
5-amino-1,3,4-thiadiazol-2-thiol, dodecylphosphonic acid, a
combination of BTA and TAZ or any other combination thereof. When
present, the composition includes at least 0.01 wt % corrosion
inhibitor, based on the total weight of the composition.
[0040] The inclusion of the chelating agent serves to chelate the
oxidized copper and/or tungsten metals in the post-etch residue
species and/or react with TiN and/or titanium-containing residues.
Suitable chelating agents include, but are not limited to:
fluorinated .beta.-diketone chelating agents such as
1,1,1,5,5,5-hexafluoro-2,4-pentanedione (hfacH),
1,1,1-trifluoro-2,4-pentanedione (tfac), and acetylacetonate
(acac); iminodiacetic acid; pyrazolates; amidinates; guanidinates;
ketoimines; dienes; polyamines; ethylenediaminetetraacetic acid
(EDTA); 1,2-cyclohexanediamine-N,N,N',N'-tetraacetic acid (CDTA);
etidronic acid; methanesulfonic acid; hydrochloric acid; acetic
acid; acetylacetone; alkylamines; arylamines; glycolamines;
alkanolamines; triazoles; thiazoles; tetrazoles; imidazoles;
1,4-benzoquinone; 8-hydroxyquinoline; salicylidene aniline;
tetrachloro-1,4-benzoquinone; 2-(2-hydroxyphenyl)-benzoxazol;
2-(2-hydroxyphenyl)-benzothiazole; hydroxyquinoline sulfonic acid
(HQSA); sulfosalicylic acid (SSA); salicylic acid (SA);
tetramethylammonium halides, e.g., fluoride, chloride, bromide,
iodide; and amines and amine-N-oxides including, but not limited
to, pyridine, 2-ethylpyridine, 2-methoxypyridine and derivatives
thereof such as 3-methoxypyridine, 2-picoline, pyridine
derivatives, dimethylpyridine, piperidine, piperazine,
triethylamine, triethanolamine, ethylamine, methylamine,
isobutylamine, tert-butylamine, tributylamine, dipropylamine,
dimethylamine, diglycol amine, monoethanolamine,
methyldiethanolamine, pyrrole, isoxazole, 1,2,4-triazole,
bipyridine, pyrimidine, pyrazine, pyridazine, quinoline,
isoquinoline, indole, imidazole, N-methylmorpholine-N-oxide (NMMO),
trimethylamine-N-oxide, triethylamine-N-oxide, pyridine-N-oxide,
N-ethylmorpholine-N-oxide, N-methylpyrrolidine-N-oxide,
N-ethylpyrrolidine-N-oxide, 1-methylimidazole, diisopropylamine,
diisobutylamine, aniline, aniline derivatives,
pentamethyldiethylenetriamine (PMDETA), and combinations of any of
the above. Preferably, the chelating agent is methanesulfonic acid,
hydrochloric acid, PMDETA, and combinations thereof. When present,
the composition includes at least 0.01 wt % chelating agent, based
on the total weight of the composition.
[0041] The complexing agents preferably have a high affinity for
aluminum-containing residues. Complexing agents contemplated
include, but are not limited to, aminocarboxylic acids, organic
acids and derivatives thereof, phosphonic acids and derivatives
thereof, and combinations thereof including:
butylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid
(DTPA), ethylenediaminetetrapropionic acid,
(hydroxyethyl)ethylenediaminetriacetic acid (HEDTA),
N,N,N',N'-ethylenediaminetetra(methylenephosphonic) acid (EDTMP),
triethylenetetraminehexaacetic acid (TTHA),
1,3-diamino-2-hydroxypropane-N,N,N',N'-tetraacetic acid (DHPTA),
methyliminodiacetic acid, propylenediaminetetraacetic acid,
1,5,9-triazacyclododecane-N,N',N''-tris(methylenephosphonic acid)
(DOTRP),
1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetrakis(methylenep-
hosphonic acid) (DOTP), nitrilotris(methylene)triphosphonic acid,
diethylenetriaminepenta(methylenephosphonic acid) (DETAP),
aminotri(methylenephosphonic acid),
1-hydroxyethylidene-1,1-diphosphonic acid (HEDP),
bis(hexamethylene)triamine phosphonic acid,
1,4,7-triazacyclononane-N,N',N''-tris(methylenephosphonic acid
(NOTP), 2-phosphonobutane-1,2,4-tricarboxylic acid,
nitrilotriacetic acid (NTA), citric acid, tartaric acid, gluconic
acid, saccharic acid, glyceric acid, oxalic acid, phthalic acid,
maleic acid, mandelic acid, malonic acid, lactic acid,
dihydroxybenzoic acid, catechol, gallic acid, propyl gallate,
pyrogallol, cysteine, dihydroxysalicylic acid, glyphosphate,
N-(Phosphonomethyl)-iminodiacetic acid, formic acid, propanoic
acid, butanoic acid, sulfate ions, N-(2-Hydroxyethyl)-iminodiacetic
acid, pyridine-2,5-dicarboxylic acid, pyridine-2,6-dicarboxylic
acid, 7-Iodo-8-hydroxyquinoline-5-sulfonic acid,
2-amino-2-propylphosphonic acid, 1,2-dihydroxybenzene-4-sulfonic
acid, 4,5-dihydroxy-1,3-benzene disulfonic acid (Tiron), solochrome
violet R, 3-hydroxy-2-naphthoic acid, chromotropic acid,
nitroacetic acid, oxydiacetic acid, thiodiacetic acid,
8-hydroxy-7-(arylazo)-quinoline-5-sulfonic acid, 2-oxobutanoic
acid, acetoacetic acid, phenylserine, L-ascorbic acid, squaric
acid, acetohydroxamic acid, 3-hydroxy-5,7-disulfo-2-naphthoic acid,
2,3-dihydroxynaphthalene-6-sulfonic acid, sulfoxine, oxine,
succinic acid, 3,4-dihydroxybenzoic acid,
2-(3,4-dihydroxyphenyl)-2-(1,1-benzopyran)-3,5,7-triol,
3-hydroxy-7-sulfo-2-naphthoic acid,
1,2-dihydroxynaphthalene-4-sulfonic acid,
N,N-bis(2-hydroxyethyl)glycine, N-(phosphonomethyl)-iminodiacetic
acid, iminobis(methylenephosphonic acid), D-gluconic acid, tartaric
acid, 1-oxopropane-1,2-dicarboxylic acid,
propane-1,2,3-tricarboxylic acid,
N,N',N''-tris[2-(N-hydroxycarbamoyl)ethyl]-1,3,5-benzenetricarboxamide
(BAMTPH), desferriferrioxamine-B,
1,7-dihydroxy-4-sulfo-2-naphthanoic acid, aspartic acid, glutamic
acid, pyridoxal-5-(dihydrogenphosphate), pyridoxal,
amino(phenyl)methylene-diphosphoric acid, ethylene glycol
tetraacetic acid (EGTA),
ethylenebis(imino-(2-hydroxyphenyl)methylene(methyl)-phosphonic
acid)), N-(2-hydroxyethyl)-ethylenedinitrilo-N,N',N'-triacetic
acid, trimethylenedinitrilotetracetic acid,
(2-dihydroxytrimethylene)-dinitrilotetracetic acid, xylenol orange,
methylthymol blue, 3-hydroxyglutamic acid, L-phosphoserine,
DL-amino-3-phosphopropanoic acid, and combinations thereof.
[0042] The compositions may optionally further include a surfactant
to assist in residue removal, wet the surface, and/or prevent
residue redeposition. Illustrative surfactants include, but are not
limited to, amphoteric salts, cationic surfactants, anionic
surfactants, fluoroalkyl surfactants, SURFONYL.RTM. 104,
TRITON.RTM. CF-21, ZONYL.RTM. UR, ZONYL.RTM. FSO-100, ZONYL.RTM.
FSN-100, 3M Fluorad fluorosurfactants (i.e., FC-4430 and FC-4432),
dioctylsulfosuccinate salt, 2,3-dimercapto-1-propanesulfonic acid
salt, dodecylbenzenesulfonic acid, polyethylene glycols,
polypropylene glycols, polyethylene or polypropylene glycol ethers,
carboxylic acid salts, R.sub.1 benzene sulfonic acids or salts
thereof (where the R.sub.1 is a straight-chained or branched
C.sub.8-C.sub.18 alkyl group), amphiphilic fluoropolymers,
polyethylene glycols, polypropylene glycols, polyethylene or
polypropylene glycol ethers, carboxylic acid salts,
dodecylbenzenesulfonic acid, polyacrylate polymers, dinonylphenyl
polyoxyethylene, silicone or modified silicone polymers, acetylenic
diols or modified acetylenic diols, alkylammonium or modified
alkylammonium salts, as well as combinations comprising at least
one of the foregoing surfactants, sodium dodecyl sulfate,
zwitterionic surfactants, aerosol-OT (AOT) and fluorinated
analogues thereof, alkyl ammonium, perfluoropolyether surfactants,
2-sulfosuccinate salts, phosphate-based surfactants, sulfur-based
surfactants, and acetoacetate-based polymers. When present, the
composition includes at least 0.01 wt % surfactant, based on the
total weight of the composition.
[0043] The compositions may further include a source of silica. The
silica may be added to the composition as a fine silica powder, or
as a tetraalkoxysilane such as TEOS, preferably at a ratio of
etchant to silica source of about 4:1 to about 5:1. In a
particularly preferred embodiment, the etchant source is
fluorosilicic acid and the silica source is TEOS. The preferred
embodiment further includes a glycol based solvent to facilitate
the dissolution of the silica source in the composition. When
present, the composition includes at least 0.01 wt % silica, based
on the total weight of the composition.
[0044] The low-k passivating agents may be included to reduce the
chemical attack of the low-k layers and to protect the wafer from
additional oxidation. Boric acid is a presently preferred low-k
passivating agent, although other hydroxyl additives may also be
advantageously employed for such purpose, e.g.,
3-hydroxy-2-naphthoic acid, malonic acid, iminodiacetic acid, and
mixtures thereof. Preferably, the low-k passivating agent comprises
iminodiacetic acid, boric acid, or a combination thereof. When
present, the composition includes at least 0.01 wt % low-k
passivating agent, based on the total weight of the composition.
Preferably, less than 2 wt. % of the underlying low-k material is
etched/removed using the removal compositions described herein,
more preferably less than 1 wt. %, most preferably less than 0.5
wt. %, based on the total weight of the underlying low-k
material.
[0045] In a particularly preferred embodiment, the aqueous
composition comprises, consists of, or consists essentially of BTA,
TAZ, ammonium bifluoride, boric acid, and water. In another
particularly preferred embodiment, the aqueous composition
comprises, consists of, or consists essentially of BTA, TAZ,
ammonium bifluoride, tetrabutylammonium tetrafluoroborate, boric
acid, and water. In still another particularly preferred
embodiment, the aqueous composition comprises, consists of, or
consists essentially of ammonium bifluoride, boric acid,
dodecylphosphonic acid, and water.
[0046] The aqueous compositions described herein are preferably
devoid of abrasive material (e.g., silica, alumina, other abrasives
used during chemical mechanical polishing processes), oxidizing
agents, ammonia, strong bases, and an amidoxime complexing agent.
Although disclosed as an optional component, most preferably the
aqueous compositions are substantially devoid of organic solvents
and silica sources.
[0047] In another embodiment, the aqueous compositions described
herein further include post-plasma etch residue, wherein the
post-plasma etch residue comprises residue material selected from
the group consisting of titanium-containing residue,
polymeric-residue, copper-containing residue, tungsten-containing
residue, cobalt-containing residue, and combinations thereof. The
residue material may be dissolved and/or suspended in the aqueous
compositions.
[0048] In still another embodiment, the aqueous compositions
described herein further include titanium nitride material. The TiN
material may be dissolved and/or suspended in the aqueous
compositions.
[0049] In one embodiment, the compositions are useful for the
selective removal of TiN, sidewall residue, and/or post-etch
residue without substantially etching patterned or blanket tungsten
layers, copper layers and/or ULK layers. In another embodiment, the
compositions are useful for the selective removal of sidewall
residue, and/or post-etch residue without substantially etching
patterned or blanket tungsten layers, TiN, copper layers and/or ULK
layers.
[0050] In addition to a liquid solution, it is also contemplated
herein that the compositions of both aspects of the invention may
be formulated as foams, fogs, subcritical or supercritical fluids
(i.e., wherein the solvent is CO.sub.2, etc., instead of
water).
[0051] Advantageously, the cleaning compositions described herein
effectively remove post-plasma etch residue from the top surface,
the sidewalls, and the vias and lines of the microelectronic device
without compromising the ILD, capping layers, and/or the metal
interconnect layers present on the device. In addition, the
compositions may be used regardless of whether the trench or the
via is etched first.
[0052] It will be appreciated that in general cleaning
applications, it is common practice to make highly concentrated
forms to be used at extreme dilutions. For example, the cleaning
compositions may be manufactured in a more concentrated form,
including at least about 20 wt % water for solubility purposes, and
thereafter diluted with additional solvent (e.g., water and/or
organic solvent) at the manufacturer, before use, and/or during use
at the fab. Dilution ratios may be in a range from about 0.1 part
diluent:1 part removal composition concentrate to about 100 parts
diluent:1 part removal composition concentrate. It is understood
that upon dilution, the weight percent ratios of many of the
components of the removal composition will remain unchanged.
[0053] The compositions described herein are easily formulated by
simple addition of the respective ingredients and mixing to
homogeneous condition. Furthermore, the compositions may be readily
formulated as single-package formulations or multi-part
formulations that are mixed at the point of use, preferably
multi-part formulations. The individual parts of the multi-part
formulation may be mixed at the tool or in a storage tank upstream
of the tool. The concentrations of the respective ingredients may
be widely varied in specific multiples of the composition, i.e.,
more dilute or more concentrated, and it will be appreciated that
the compositions described herein can variously and alternatively
comprise, consist or consist essentially of any combination of
ingredients consistent with the disclosure herein.
[0054] Accordingly, another aspect relates to a kit including, in
one or more containers, one or more components adapted to form the
compositions described herein. Preferably, the kit includes, in one
or more containers, the preferred combination of at least one
corrosion inhibitor, optionally water, optionally at least one
etchant, optionally at least one chelating agent, optionally at
least one passivating agent, and optionally at least one complexing
agent, for combining with water at the fab or the point of use. The
containers of the kit must be suitable for storing and shipping
said cleaning composition components, for example, NOWPak.RTM.
containers (Advanced Technology Materials, Inc., Danbury, Conn.,
USA). The one or more containers which contain the components of
the removal composition preferably include means for bringing the
components in said one or more containers in fluid communication
for blending and dispense. For example, referring to the
NOWPak.RTM. containers, gas pressure may be applied to the outside
of a liner in said one or more containers to cause at least a
portion of the contents of the liner to be discharged and hence
enable fluid communication for blending and dispense.
Alternatively, gas pressure may be applied to the head space of a
conventional pressurizable container or a pump may be used to
enable fluid communication. In addition, the system preferably
includes a dispensing port for dispensing the blended cleaning
composition to a process tool.
[0055] Substantially chemically inert, impurity-free, flexible and
resilient polymeric film materials, such as high density
polyethylene, are preferably used to fabricate the liners for said
one or more containers. Desirable liner materials are processed
without requiring co-extrusion or barrier layers, and without any
pigments, UV inhibitors, or processing agents that may adversely
affect the purity requirements for components to be disposed in the
liner. A listing of desirable liner materials include films
comprising virgin (additive-free) polyethylene, virgin
polytetrafluoroethylene (PTFE), polypropylene, polyurethane,
polyvinylidene chloride, polyvinylchloride, polyacetal,
polystyrene, polyacrylonitrile, polybutylene, and so on. Preferred
thicknesses of such liner materials are in a range from about 5
mils (0.005 inch) to about 30 mils (0.030 inch), as for example a
thickness of 20 mils (0.020 inch).
[0056] Regarding the containers for the kits, the disclosures of
the following patents and patent applications are hereby
incorporated herein by reference in their respective entireties:
U.S. Pat. No. 7,188,644 entitled "APPARATUS AND METHOD FOR
MINIMIZING THE GENERATION OF PARTICLES IN ULTRAPURE LIQUIDS;" U.S.
Pat. No. 6,698,619 entitled "RETURNABLE AND REUSABLE, BAG-IN-DRUM
FLUID STORAGE AND DISPENSING CONTAINER SYSTEM;" and U.S. Patent
Application No. 60/916,966 entitled "SYSTEMS AND METHODS FOR
MATERIAL BLENDING AND DISTRIBUTION" filed on May 9, 2007 in the
name of John E. Q. Hughes, and PCT/US08/63276 entitled "SYSTEMS AND
METHODS FOR MATERIAL BLENDING AND DISTRIBUTION" filed on May 9,
2008 in the name of Advanced Technology Materials, Inc.
[0057] As applied to microelectronic manufacturing operations, the
cleaning compositions are usefully employed to clean post-plasma
etch residue from the surface of the microelectronic device, and
may be applied to said surface before or after the application of
other compositions formulated to remove alternative materials from
the surface of the device. The compositions described herein do not
damage ILD materials on the device surface and preferably remove at
least 90% of the residue present on the device prior to removal
processing, more preferably at least 95%, and most preferred at
least 99% of the residue to be removed is removed.
[0058] In post-plasma etch residue removal application, the
composition may be applied in any suitable manner to the device to
be cleaned, e.g., by spraying the composition on the surface of the
device to be cleaned, by dipping the device to be cleaned in a
static or dynamic volume of the composition, by contacting the
device to be cleaned with another material, e.g., a pad, or fibrous
sorbent applicator element, that has the composition absorbed
thereon, or by any other suitable means, manner or technique by
which the composition is brought into removal contact with the
device to be cleaned. Further, batch or single wafer processing is
contemplated herein.
[0059] In use of the compositions for removing post-plasma etch
residue from microelectronic devices having same thereon, the
composition typically is statically or dynamically contacted with
the device for a time of from about 1 minute to about 30 minutes,
preferably about 1 minute to 10 minutes, at temperature in a range
of from about 20.degree. C. to about 90.degree. C., preferably
about 40.degree. C. to about 70.degree. C., and most preferably
about 50.degree. C. to about 60.degree. C. Preferably, the
contacting is static. Such contacting times and temperatures are
illustrative, and any other suitable time and temperature
conditions may be employed that are efficacious to at least
partially remove the post-etch residue material from the device.
"At least partial removal" of the residue material from the
microelectronic device corresponds to at removal of at least 90% of
the material, preferably at least 95% removal. Most preferably, at
least 99% of said residue material is removed using the
compositions described herein.
[0060] Following the achievement of the desired removal action, the
compositions may be readily removed from the device to which it has
previously been applied, e.g., by rinse, wash, or other removal
step(s), as may be desired and efficacious in a given end use
application of the compositions described herein. For example, the
device may be rinsed with a rinse solution including deionized
water and/or dried (e.g., spin-dry, N.sub.2, vapor-dry etc.).
[0061] When necessary, a post-clean bake step and/or an isopropanol
vapor-dry step may be necessary to remove non-volatile materials
that may absorb into the pores of the ILD materials so as not to
change the capacitance of the low-k dielectric materials.
[0062] Another aspect relates to the improved microelectronic
devices made according to the methods described herein and to
products containing such microelectronic devices.
[0063] A still further aspect relates to methods of manufacturing
an article comprising a microelectronic device, said method
comprising contacting the microelectronic device with a composition
for sufficient time to clean post-plasma etch residue from the
microelectronic device having said residue thereon, and
incorporating said microelectronic device into said article,
wherein the composition includes at least one corrosion inhibitor,
water, optionally at least one chelating agent, optionally at least
one etchant, optionally at least one passivating agent, and
optionally at least one complexing agent.
[0064] A still further aspect relates to methods of manufacturing
an article comprising a microelectronic device, said method
comprising contacting the microelectronic device with a composition
for sufficient time to clean post-plasma etch residue from the
microelectronic device having said residue thereon, and
incorporating said microelectronic device into said article,
wherein the composition includes at least one corrosion inhibitor,
water, optionally at least one chelating agent, optionally at least
one etchant, optionally at least one passivating agent, and
optionally at least one complexing agent.
[0065] In yet another aspect, the compositions described herein may
be utilized in other aspects of the microelectronic device
manufacturing process, i.e., subsequent to the post-plasma etch
residue cleaning step. For example, the compositions may be used to
remove post-ash residue and/or they may be diluted and used as a
post-chemical mechanical polishing (CMP) clean. Alternatively, the
compositions described herein may be used to remove contaminating
materials from photomask materials for re-use thereof.
[0066] In yet another aspect, an article of manufacture is
described, said article comprising a microelectronic device
substrate, residue material, and a cleaning composition, wherein
the cleaning composition may be any composition described herein,
and wherein the residue material is selected from the group
consisting of titanium-containing residue, polymeric-residue,
copper-containing residue, tungsten-containing residue,
cobalt-containing residues, and combinations thereof.
[0067] Although the invention has been variously disclosed herein
with reference to illustrative embodiments and features, it will be
appreciated that the embodiments and features described hereinabove
are not intended to limit the invention, and that other variations,
modifications and other embodiments will suggest themselves to
those of ordinary skill in the art, based on the disclosure herein.
The invention therefore is to be broadly construed, as encompassing
all such variations, modifications and alternative embodiments
within the spirit and scope of the claims hereafter set forth.
* * * * *