US 20020004360A1
(19) United States
(12) Patent Application Publication (10) Pub. No.: US 2002/0004360 A1
Ota ct al.
(43) Pub. Date:
(54) POLISHING SLURRY
(76)
(30)
Inventors: Katsuhiro 0m, Yokohama (JP); Akio
Correspondence Addressl
Foreign Application Priority Data
Jun. 1, 2000
Sam)’ Fullsawa (JP)
Jan. 10, 2002
(JP) ......................................... .. 00-164650
Publication Classi?cation
(51)
(52)
Int. Cl.7 .............................. .. B24B 1/00; B24B 7/19
US. Cl. .............................................................. .. 451/60
ANTONELLI TERRY STOUT AND KRAUS
SUITE 1800
1300 NORTH SEVENTEENTH STREET
(57)
ABSTRACT
A polishing slurry prepared by dispersing in a dispersion
ARLINGTON, VA 22209
medium, abrasive grains comprised of a material having a
solubility in the dispersion medium at 25° C., of 0.001 g/ 100
g or higher is used to effectively remove any abrasive grains
standing adherent to the surfaces of objects to be polished or
the interiors of polishing apparatus after polishing.
(21) Appl, No;
09/797,940
(22) Filed:
Mar. 5, 2001
1
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Jan. 10, 2002 Sheet 1 0f 2
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Jan. 10, 2002
US 2002/0004360 A1
POLISHING SLURRY
[0001] This application is based on Japanese Patent Appli
cation No. 2000-164650 ?led in Japan, the contents of Which
are incorporated hereinto by reference.
BACKGROUND OF THE INVENTION
[0002]
1. Field of the Invention
[0003]
This invention relates to a polishing slurry suited
for the polishing of electronic materials, magnetic materials
and optical materials, a polishing method using the polishing
slurry, and a process for fablicating semiconductor devices.
and abrasive grains dispersed in the dispersion medium; the
abrasive grains comprising a material having a solubility in
the dispersion medium at normal temperature (25° C.), of
0.001 g/100 g or higher. The present invention also provides
a polishing slurry comprising a dispersion medium and
abrasive grains dispersed in the dispersion medium; the
abrasive grains comprising organic matter. In either of
inorganic matter and organic matter, the abrasive grains may
preferably have a solubility in the dispersion medium, of
0.001 g/100 g or higher, and more preferably 0.1 g/100 g or
higher. In the case When the abrasive grains are comprised
of organic matter, it may preferably have a melting point of
30° C. or above so that it can be present in the state of a solid
[0004] 2. Description of the Related Art
in usual polishing steps.
[0005]
more and more trend toWard ?ner and more multilayered
[0010] The present invention still also provides a polish
ing method of polishing an object to be poslished by using
any of these polishing slurries of the present invention, and
Wiring. This has brought about a tendency toWard a larger
difference in height of interlayer insulating ?lms. Because of
such a method.
In recent years, in order to achieve higher integra
tion of semiconductor integrated circuits, Wiring techniques
a process for fabricating a semiconductor device by using
this difference in height of interlayer insulating ?lms, any
Wiring formed thereon may have a loW processing precision
and a loW reliability. Hence, polishing techniques for
improving smoothness of interlayer insulating ?lms have
become very important. For eXample, Japanese Patent
Application Laid-open No. 9-22885 discloses chemical
mechanical polishing of interlayer insulating ?lms formed
on semiconductor Wafers.
[0006] Polishing slurries conventionally used for semicon
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] These and other features, objects and advantages of
the present invention Will become more apparent from the
folloWing description When taken in conjunction With the
accompanying draWings Wherein;
[0012] FIG. 1A and FIG. 1B illustrate basic concept of
the present invention; and
ductor substrate may include, e.g., as disclosed in Japanese
[0013]
Patent Application Laid-open No. 11-111657, an acidic
showing some steps in a process of producing a semicon
ductor substrate.
(about pH 3) alumina slurry, a neutral silica slurry having
FIG. 2A to FIG. 2D are a cross-sectional vieWs
silica particles dispersed therein as abrasive grains, and an
alkaline silica slurry prepared by adding sodium hydroxide
or the like to this neutral slurry. Besides these, as abrasive
grains, this publication further discloses oXide particles such
as alumina particles, titanium oXide particles and Zirconium
oXide particles obtained by hydrolyZing metal alkoXides.
DETAILED DESCRIPTION OF THE DRAWINGS
[0014]
On the abrasive grains contained in the polishing
slurry of the present invention, there are no particular
limitations as long as they are those having a solubility in its
dispersion medium, of 0.001 g/100 g or higher at normal
[0007] Abrasive grains comprised of metals (inclusive of
temperature, and capable of being present in the dispersion
semi-metals) or metal oXides, used in these conventional
polishing slurries, adhere to the surfaces of objects to be
polished and to the interiors of polishing apparatus, e.g., to
pads, dressers and so forth, and remain thereon after pol
ishing to damage smoothness and ?lm properties unless no
medium in the state of a solid. They may be comprised of
inorganic matter or organic matter, but may preferably be
those Which do not affect any properties of objects to be
measure is taken therefor. Accordingly, as a post treatment
of polishing, as disclosed in, e.g., Japanese Patent Applica
tion Laid-open No. 9-22885, Washing With an alkaline
solution or scrubbing Washing has been carried out. HoW
ever, for the abrasive grains comprised of metals (inclusive
of semi-metals) or metal oXides, used in these conventional
polishing slurries, it has been dif?cult to be completely
removed by Washing, and has been very dif?cult to be
removed by Washing especially When the abrasive grains
stand stuck in the semiconductor substrate.
SUMMARY OF THE INVENTION
[0008] Accordingly, an object of the present invention is to
provide a polishing slurry Whose abrasive grains having
remained after polishing are removable With ease, a polish
ing method and a semiconductor device fabrication process
Which make use of this polishing slurry.
[0009] To achieve the above object, the present invention
provides a polishing slurry comprising a dispersion medium
polished. For eXample, When the objects to be polished are
semiconductor substrate members, it is preferable to use
materials Which do not contain sodium, calcium or the like.
[0015] Inorganic compounds usable as the abrasive grains
in the present invention may include;
[0016] Ag compounds such as AgBr, AgCl, AgClO4,
Ag2CrO4, AgF, AgNO3, Ag2O and Ag2SO4;
[0017] Al compounds such as AlCl3, Al(NO3)3,
A12(SO4)3, A1(C1O4)3.9H2O, AlCs(SO4)2.12H2O,
A1F3.3H2O,A1K(SO4)2.2H2O,A1NH4(SO4)2.12H2O
and AlNa(SO4)2.12H2O;
[0018] As compounds such as As2O3;
[0019] Ba compounds such as BaBr2, BaCl2,
Ba(ClO3)2, BaI2, Ba(NO2)2, Ba(NO3)2, Ba(OH)2,
BaS and BaSO4;
[0020] Be compounds such as Be(ClO4)2, Be(NO3)2
and BeSO4;
[0021] Br compounds such as CaBr2;
Jan. 10, 2002
US 2002/0004360 A1
[0022] Ca compounds such as CaCO3, CaCl2,
[0044] Na compounds such as NaBO2, NaBr,
Ca(ClO4)2, CaCrO4, CaI2, Ca(IO3)2, Ca(NO3)2,
Ca(OH)2 and CaSO4;
NaBrO3, NaCN, Na2CO3, NaCl, NaClO2, NaClO3,
NaClO4, Na2CrO4, Na2Cr2O7, NaF, Na4[Fe(CN)6],
NaHCO3, NaH2PO4, Na2HPO4, NaI, NaIO3,
NaMnO4, NaNO2, NaNO3, NaOH, Na4P2O7, NaZS,
NaSCN, Na2SO3, Na2SO4, Na2O3, Na3VO4 and
[0023] Cd compounds such as CdBr2, CdCl2,
Cd(C1O3)2, Cd(C1O4)2, c0112, Cd(NO3)2 and CdSO4;
[0024] Ce compounds such as Ce2(SO4)3, Ce(IO3)3,
Ce2Mg3(NO3)12~24H2O> Ce (NH4)2(NO3)5-4H2O,
Ce (NO3)4, Ce(NH4)(NO3)6 and Ce2(WO4)3;
[0045] Nd compounds such as NdCl3, Nd(NO3)3 and
[0025] C0 compounds such as CoBr2, CoCl2,
[0046] Ni compounds such as NiBr2, NiCl2,
Co(ClO3)2, CoI2, Co(NO3)2 and CoSO4;
[0026] Cr compounds such as Cr(NO3)3 and CrO3;
Nd2(SO4)3;
[0047] Pb compounds such as PbBr2, PbCl2, PbI2,
[0027] Cs compounds such as CsCl, CsCl3, CsClO4,
CsI, CsNO3 and Cs2SO4;
Pb(NO3)2 and PbSO4;
[0048] Pr compounds such as PrCl3, Pr(NO3)3 and
Pr2(SO4)3;
[0028] Cu compounds such as CuBr2, CuCl2,
[0049] Pt compounds such as PtCl4, [PtCl(NH3)5]Cl3
and [Pt(NH3)6]Cl4;
[0050] Rb compounds such as RbBr, RbCl, RbClO3,
RbC1O4, Rb2CrO4, Rb2Cr2O7, RbI, RbNo3 and
[0029] Fe compounds such as FeBr2, FeCl2, FeCl3,
Fe(ClO4)2, Fe(ClO4)3, Fe(NO3)2, Fe(NO3)3, F6504,
FeF3.3H2O,
FeK2(SO4)2.6H2O,
FeNH4(SO4)2.12H2O and Fe(NH4)2(SO4)2.6H2O;
[0030] Ge compounds such as GeO2;
[0031] B compounds such as H3BO3;
[0032] Cl compounds such as HClO4.H2O;
[0033] P compounds such as H3PO4;
Rb2SO4;
[0051] Sb compounds such as SbCl3;
[0052] Se compounds such as SeO2;
[0053] Sm compounds such as SmCl3;
[0054] Sr compounds such as SrBr2, SrCl2,
Sr(ClO3)2, Sr(ClO4), SrI2, Sr(NO2)2, Sr(NO3)2,
Sr(OH)2 and SrSO4;
[0055] Th compounds such as Th(NO3)4 and
Them»;
[0034] Hg compounds such as HgBr2, HgCl2,
Hgzclz, and Hg(C1O4)2;
[0035]
[0056] T1 compounds such as TlBr, TlCl, TlClO4,
T1NO2, T1NO3, TlOH and T12SO4;
I compounds such as I2;
[0057] U compounds such as U(SO4)2, UO2CrO4,
[0036] In compounds such as InCl3;
UO2(NO3)2 and UO2SO4;
[0037] K compounds such as KBr, KBrO3, K2CO3,
KCl, KC1O3, KC1O4, K2CrO4, K2Cr2O7, KF,
K3[Fe(CN)6], K4[Fe(CN)6], KHCO3, KH2PO4,
K2HPO4, KI, KIO3, KIO4, KMnO4, K2MnO4,
KNO3, KOH, K3PO4, KSCN, K2503, K2504,
KHF2, KHSO4 and KNO2;
[0058] Y compounds such as YBr3, YCl3, Y(NO3)3
and Y2(SO4)3;
[0059] Yb compounds such as Yb2(SO4)3; and
[0060] Zn compounds such as ZnBr2, ZnCl2,
Zn(ClO2)2, Zn(ClO3)2, Zn(ClO4)2, ZnI2, Zn(NO3)2
[0038] La compounds such as LaCl3, La(NO3)3 and
and ZnSO4.
La2(SO4);
[0039] Li compounds such as LiBr, LiBrO3, Li2CO3,
LiCl, LiC1O4, Li2CrO4, LiI, LiNO3, LiOH and
Li2SO4;
[0040] Mg compounds such as MgBr2, MgCO3,
MgCl2,
Mg(ClO3)2,
Mg(ClO4)2,
MgCrO4,
MgMoO4, Mg(NO3)2, MgSO3 and MgSO4,;
[0041] Mn compounds such as MnBr2, MnCl2,
Mn(NO3)2 and MnSO4;
[0042] Mo compounds such as M003;
[0061]
Of these, it is preferable to use Al compounds, Ce
compounds, Cu compounds, Fe compounds and/or NH4
compounds. In particular, NH4 compounds are preferred
because they do not deteriorate any semiconductor products.
As the most preferred materials for abrasive grains, they
may include NH4Cl, NH4ClO4, NH4HCO3, Ce2(SO4),
CuCl2 and CuSO4.
[0062] As speci?c eXamples of the organic matter usable
as the abrasive grains in the present invention, it may include
organic acids (organic acids and esters or salts thereof),
alcohol compounds, ether compounds, phenolic compounds
and nitrogen-containing compounds. These organic com
pounds are commonly formed of crystals softer than inor
ganic matter and hence may hardly scratch polishing
objects. Thus, these are particularly advantageous for pol
ishing soft objects such as insulating ?lms formed of organic
materials or oXides of metals or semi-metals.
Jan. 10, 2002
US 2002/0004360 A1
[0063] The organic acids may include adipic acid, acetyl
[0068] Of these, adipic acid, citric acid hydrate and mal
salicylic acid, salts of benZoic acid (such as potassium
onic acid are preferred because the metal copper can be
benZoate and strychinine benZoate), o-nitrobenZoic acid,
prevented from corroding. Sucrose is also preferred because
p-hydroxybenZoic acid, carbamic esters (such as ethyl car
bamate), salts of formic acid (such as potassium formate and
it makes it easy to dispose of Waste liquor and does not
magnesium formate dihydrate), citric acid, citric acid
hydrate, chloroacetic acid (i.e., ot-chloroacetic acid, [3-chlo
roacetic acid or y-chloroacetic acid), succinic acid, salts of
oxalic acid (such as ammonium oxalate and potassium
oxalate), oxalic acid hydrate, tartaric acid (i.e., (+)-tartaric
deteriorate any semiconductor products.
[0069] There are no particular limitations on the disper
sion medium as long as it is a liquid capable of dissolving
these abrasive-grain materials. For example, the folloWing
materials (1) to (5) are usable as the dispersion medium.
acid or (—)-tartaric acid), nicotinic acid, nicotinic acid hydro
chloride, maleic acid, malonic acid, DL-mandelic acid,
[0070] (1) An acidic solution (preferably pH 2 to 4)
DL-malic acid, salts of valeric acid (such as silver valerate),
salts of gluconic acid (such as potassium gluconate), salts of
cinnamic acid (such as calcium cis-cinnamate), salts of
acetic acid (such as uranyl acetate dihydrate, calcium
acetate, cesium acetate, magnesium acetate tetrahydrate and
lithium acetate dihydrate), salts of salicylic acid (such as
acid, hydrochloric acid, sulfuric acid, nitric acid, acetic
ammonium salicylate, potassium salicylate hydrate), trichlo
roacetic acid, salts of naphthalene sulfonic acid (such as
ammonium l-naphthalene sulfonate and ammonium 2-naph
containing at least one acid selected from hydro?uoric
acid and organic acids.
[0071] (2) An alkaline solution (preferably pH 9 to 11)
containing at least one base selected from ammonium
hydroxide, potassium hydroxide, sodium hydroxide
and amines.
[0072]
(3) Asolution containing a salt of the above acid
With the above base.
thalene sulfonate), hippuric acid, hippuric esters (such as
ethyl hippurate), salts of phenoxyacetic acid (such as ammo
nium phenoxyacetate), salts of fumaric acid (such as calcium
fumarate trihydrate), salts of butyric acid (such as calcium
butyrate hydrate and barium butyrate), and amino acids.
[0064]
As the amino acids, usable are, e.g., L-ascorbic
acid, glycine, DL-ot-aminoisobutyric acid, aminobutyric
acid (such as DL-ot-aminobutyric acid, 3-aminobutyric acid
or 4-aminobutyric acid), aminopropionic acid (such as DL
alanine, L-alanine or [3-alanine), orotic acid ester salts (such
as ethylammonium orotate and benZylammonium orotate),
and DL-valine.
[0065] The alcohol compounds may include saccharides
such as D-glucose, D-glucose hydrate, sucrose and D-man
nitol, and salt of glycerophosphoric acid (such as calcium
glycerophosphate). The ether compounds may include
18-croWn-6. Incidentally, the saccharides listed here are
monosaccharides and disaccharides, and may also be trisac
charide or higher polysaccharides.
[0066] The phenolic compounds may include catechol,
2-naphthol, m-nitrophenol, hydroquinone, resorcinol, gly
cidylglycine and pyrogallol.
[0067] The nitrogen-containing compounds may include
amine compounds, amide compounds, imide compounds,
nitro compounds, ammonium salts, and heterocyclic com
pounds containing nitrogen as a heteroatom. Stated speci?
cally, usable are acetanilide, acetamide, aniline hydrochlo
ride, ethylenediaminetetraacetic acid, caffeine, urea,
thiourea, 2,4,6-trinitrotoluene, phenylenediamine (i.e.,
o-phenylenediamine, ot-m-phenylenediamine, [3-m-phe
nylenediamine or p-phenylenediamine), acrylamide, antipy
rine, quinine salts (such as quinine hydrochloride dihydrate
and quinine sulfate heptahydrate), cocaine hydrochloride,
codeine phosphate dehydrate, succinimide hydrate, taurine,
tetraethyl ammonium salts (such as tetraethylammonium
[0073] (4) Water.
[0074] (5) An organic solvent (preferably an aliphatic
alcohol having 1 to 5 carbon atoms.
[0075] The dispersion medium may optionally further
contain hydrogen peroxide and ammonium ?uoride, and
may also appropriately contain additives such as an anti
corrosive and a dispersant. For the purpose of stable disper
sion of the abrasive grains, it is desirable for the abrasive
grain material to stand dissolved in saturation in the
dispersion medium. The abrasive-grain material standing
dissolved in the dispersion medium may also function as a
surface-active agent, a dispersant, an anti-corrosive, a buffer
or the like.
[0076] In the present invention, the dispersion medium
may optionally still further contain at least one of a cationic
surface-active agent, an anionic surface-active agent, an
amphoteric surface-active agent and an organic solvent.
Such various surface-active agents may each be used in a
concentration not higher than the critical micellar concen
tration or not higher than 0.01 mol/L based on the total
Weight of the dispersant, in order to avoid agglomeration of
abrasive grains and ensure a stable dispersibility.
[0077] The abrasive grains in the present invention may
have any grain diameter Without any particular limitations,
and may appropriately be determined in accordance With
polishing objects, smoothness required, and so forth. To
obtain abrasive grains having a speci?c siZe, a method is
available in Which the above abrasive grains, having been
dried, are pulveriZed and then classi?ed With a sieve.
Another method is also available in Which a solution having
the abrasive grains dissolved therein is atomiZed by means
of an atomiZer, and the abrasive grains standing atomiZed are
collected and then dried, folloWed by classi?cation With a
sieve.
chloride, tetraethylammonium bromide and tetraethylam
[0078]
monium iodide), tetrapropylammonium salts (such as tetra
dispersed in the polishing slurry in a quantity (i.e., quantity
The abrasive grains in the present invention may be
propylammonium iodide), tetramethylammonium salts
of abrasive grains present in the form of a solid, per unit
(such as tetramethylammonium bromide and tetramethylam
volume, or Weight, of the polishing slurry) Which may
appropriately be determined in accordance With polishing
objects, smoothness required, polishing rate and so forth,
monium iodide), tris(hydroxymethyl)aminomethane, pyra
Zole, pteridine and hexamethylenetetramine.
Jan. 10, 2002
US 2002/0004360 A1
and may preferably be in an amount of from 1 to 50% by
tally, as the Wash liquid, any liquid capable of dissolving the
Weight, and more preferably from 1 to 20% by Weight, based
on the total Weight of the polishing slurry. In order to leave
the abrasive grains in the form of a solid Without being
dispersion medium, may appropriately be selected.
dissolved in the dispersion medium, the polishing slurry
may be prepared by adding the abrasive grains to the
dispersion medium in a quantity exceeding the solubility of
the abrasive-grain material. Accordingly, the quantity of the
abrasive grains used may appropriately be determined in
accordance With polishing conditions (the quantity and type
of the slurry, pH, temperature, additives and so forth).
[0079] The polishing slurry of the present invention makes
use of the abrasive grains that can be dissolved in the
abrasive-grain material, such as the solvent used in the
[0082] According to the present invention, any abrasive
grains standing adherent to the surfaces of objects to be
polished such as semiconductor substrates or to the interiors
of polishing apparatus after polishing can be removed in a
good ef?ciency, and hence semiconductor products and so
forth can be manufactured at a loW cost, in a high quality and
at a high yield. Moreover, according to the present invention,
the quantity of dispersion of abrasive grains in the dispersion
medium can be controlled With ease, and hence the polishing
Wear or polishing rate can delicately be controlled. Also,
since the abrasive grains can be made to dissolve, the
dispersion medium. Hence, the quantity in Which the abra
sive grains are dispersed in the polishing slurry can dynami
cally be changed in the course of polishing, by changing,
e.g., the quantity and/or temperature of the dispersion
medium. Stated speci?cally, in the present invention, the
quantity of dispersion of the abrasive grains to be dispersed
present invention is applicable not only to semiconductor
Wafers but also to substrates of thin-?lm devices, thin-?lm
in the polishing slurry in the form of a solid can be changed
disks and the like.
disposal of Waste liquid can be made Without separating the
abrasive grains from the polishing slurry. Incidentally, the
by changing the quantity of the dispersion medium in the
polishing slurry. More speci?cally, in the present invention,
the dispersion medium may be added to the polishing slurry
THE PREFERRED EMBODIMENT
so as to make the abrasive grains dissolve in part in the
[0083] Examples of the present invention are given beloW,
dispersion medium to loWer their quantity of dispersion.
Conversely, the dispersion medium may be removed in part
Which are described With reference to FIG. 2A to FIG. 2D.
The present invention is by no means limited to these
from the polishing slurry so as to recrystalliZe the abrasive
Examples.
grain material having stood dissolved in the dispersion
medium, thus abrasive grains can be made to form aneW to
[0084] In the present Examples, polishing slurries Were
make the abrasive grains become dispersed in a larger
prepared in Which abrasive grains (grain diameter: 150 nm)
quantity. Also, the temperature of the polishing slurry may
comprised of compounds as shoWn in Table 1 Were dis
persed in an amount of 30 g per 100 g of polishing slurry,
and, using these, oxide ?lms Were polished to smooth
semiconductor substrate surfaces. In Table 1, the solubility
be changed so as to change the solubility of abrasive grains
in the dispersion medium to change the quantity of disper
sion of the abrasive grains dispersed in the polishing slurry
in the form of a solid.
[0080] The present invention also provides a polishing
method of polishing an object to be polished, by using the
polishing slurry of the present invention, and a process for
fabricating a semiconductor device by using this polishing
method. The polishing slurry of the present invention is
suited for polishing electric or electronic materials, magnetic
materials and optical materials, such as resins, conductors
and ceramics, and is especially suited for polishing conduc
tor ?lms and insulating ?lms, in particular, those of semi
conductor devices, Wiring substrates and so forth, in the
of each compound at normal temperature (25° C.) is shoWn
together.
TABLE 1
Abrasive-grain
(‘70)
Example 1
NH4Cl
28.2
Inorganic
Example 2
Example 3
NH4ClO4
NH4HCO3
21.0
19.9
matter
Ce2(SO4)3
CuCl2
CuSO4
adipic acid
7.59
42.8
18.2
2.4
Organic
citric acid
62.0
matter
manufacture of electric or electronic apparatus for Which a
Example
Example
Example
Example
high smoothness and a high cleanness are required.
Example 8
[0081] For example, as shoWn in FIG. 1A, abrasive grains
Example 9
Example 10
1 stand adherent to the surface of a semiconductor Wafer
member 2, after interlayer insulating ?lms such as plasma
silicon oxide ?lms, CVD (chemical vapor deposition) sili
con oxide ?lms and PVD (physical vapor deposition) silicon
oxide ?lms have been smoothed by chemical mechanical
polishing. HoWever, according to the present invention, the
abrasive-grain material increases in solubility because of the
heat generated by polishing, and hence the abrasive grains
become dissolved in the dispersion medium, so that the
abrasive grains 1 may less adhere to the surface of the object
Solubility
material
4
5
6
7
monohydrate
succinic acid
ammonium oxalate
7.5
5.0
Example 11
sucrose
67.0
Example 12
malonic acid
32.2
[0085] (1) Preparation of Polishing Slurry:
[0086] First, to a solution prepared by dissolving
NHA‘HCO3 particles saturatedly in an ammonia solution With
a pH adjusted to 11, abrasive grains having a primary
particle diameter (particle diameter of individual abrasive
to be polished. Also, the abrasive grains 1 having adhered
grains) of 30 nm and a secondary particle diameter (particle
may be dissolved in a Wash liquid, Whereby, as shoWn in
FIG. 1B, they can completely be removed With ease. Thus,
diameter of abrasive grains standing agglomerated) of 150
compared With conventional polishing slurries, a clean pol
polishing slurry, and dispersed therein to obtain each pol
ished surface can much more easily be obtained. Inciden
ishing slurry.
nm Were further added in an amount of 30 g per 100 g of
Jan. 10, 2002
US 2002/0004360 A1
[0087] (2) Polishing Conditions:
[0088] As the polishing apparatus, a polishing apparatus
manufactured by Applied Materials, Inc. Was used, and
polishing objects Were polished setting the number of revo
lutions of the head at 90 rpm and the number of revolutions
of the platen at 90 rpm and feeding a 25° C. polishing slurry
at a feed rate of 200 mL/minute. Here, polishing temperature
Was controlled to 25° C. so that the liquid temperature did
not rise during polishing.
[0089] (3) Production of Semiconductor Substrate Mem
2. The polishing slurry according to claim 1, Wherein said
material of the abrasive grains is at least one of Ag com
pounds, Al compounds, As compounds, Ba compounds, Be
compounds, Br compounds, Ca compounds, Cd compounds,
Co compounds, Cr compounds, Cs compounds, Cu com
pounds, Fe compounds, Ge compounds, B compounds, Cl
compounds, P compounds, Hg compounds, In compounds,
K compounds, Li compounds, Mg compounds, Mn com
pounds, Mo compounds, NH4 compounds, Na compounds,
Nd compounds, Ni compounds, Pb compounds, Pr com
ber:
pounds, Pt compounds, Rb compounds, Sb compounds, Se
compounds, Sm compounds, Sr compounds, Th compounds,
[0090] First, as shoWn in FIG. 2, an oxide ?lm 4 Was
formed on a semiconductor substrate 3, and an Al Wiring 5
Was further formed thereon to produce a semiconductor
substrate member having a difference in height at the surface
pounds, Zn compounds and I compounds.
3. The polishing slurry according to claim 1, Wherein said
[FIG. 2, (a)]. On the surface of this substrate member, a
silicon nitride ?lm 6 serving as a polishing stopper layer Was
Tl compounds, U compounds, Y compounds, Yb com
material of the abrasive grains is at least one of:
AgBr, AgCl, AgClO4, Ag2CrO4, AgF, AgNO3, AgZO,
Ag2SO4,
so formed as to cover the uncovered surfaces of the oxide
?lm 4 and Wiring 5[FIG. 2,
[0091] Subsequently, an oxide ?lm 7 Was so formed by
CVD as to ?ll up the difference in height that Was formed by
the Wiring 5[FIG. 2,
Thereafter, by means of the
polishing apparatus, this oxide ?lm 7 Was so polished as to
provide a smooth surface, using the polishing slurry pre
pared in the above step
Thus, a semiconductor substrate
member 9 having an interlayer insulating ?lm 8 having a
smooth surface Was obtained.
[0092] Finally, this substrate member 9 Was Washed With
Water by means of a brush Washing assembly manufacture
by Dainippon Screen Mfg. Co., Ltd. to remove abrasive
BaBr2, BaCl2, Ba(ClO3)2, BaI2, Ba(NO2)2, Ba(NO3)2,
Ba(OH)2, BaS, BaSO4,
Be(ClO4)2, Be(NO3)2, B6504,
CaBr2, CaCO3, CaCl2, Ca(ClO4)2, CaCrO4, CaI2,
Ca(IO3)2, Ca(NO3)2, Ca(OH)2, CaSO4,
grains remaining thereon, and thereafter the surface of the
oxide ?lm 7 Was observed With an optical microscope and a
scanning electron microscope. As the result, neither scratch
nor abrasive grain buried in the oxide ?lm 7 Was seen, and
it Was con?rmable that the oxide ?lm 7 Was provided With
a good smoothness When any polishing slurries of Examples
CoBr2, CoCl2, Co(ClO3)2, C012, Co(NO3)2, CoSO4,
1 to 12 Were used.
Cr(NO3)3, CrO3,
[0093] Percentage of rejects of semiconductor substrate
members obtained in the respective Examples Was smaller
CsCl, CsClO3, CsClO4, CsI, CsNO3, Cs2SO4,
by 5% than a case in Which substrate members Were polished
using a conventional polishing slurry (silica particles of a
primary particle diameter of 30 nm and a secondary particle
diameter of 150 nm Were used as abrasive grains, Which
Were dispersed in an ammonia solution With a pH adjusted
to 11). Thus, it has become apparent that the polishing
slurries of the above Examples enable manufacture of semi
conductor products in a high quality and at a high yield.
[0094] While We have shoWn and described several
embodiments in accordance With our invention, it should be
understood that disclosed embodiments are susceptible of
changes and modi?cations Without departing from the scope
of the invention. Therefore, We do not intend to be bound by
the details shoWn and described herein but intend to cover all
such changes and modi?cations fall Within the ambit of the
appended claims.
We claim:
1. Apolishing slurry comprising a dispersion medium and
abrasive grains dispersed in the dispersion medium;
said abrasive grains are comprised of a material having a
solubility in the dispersion medium at 25° C., of 0.001
g/100 g or higher.
FeBr2, FeCl2, FeCl3, Fe (ClO4)2, Fe(ClO4)3, Fe(NO3),
Fe(NO3), F6504, FeF3.3H2O, FeK2(SO4)2.6H2O,
FeNH4(SO4)2.12H2O, Fe(NH4)2(SO4)2.6H2O,
Jan. 10, 2002
US 2002/0004360 A1
K2MnO4, KNO3, KOH, K3PO4, KSCN, K2803,
K2804, KHF2, KHSO4, KNO2,
LaCl3, La(NO3)3, La2(SO4)3, LiBr, LiBrO3, Li2CO3,
LiCl, LiC1O4, Li2CrO4, LiI, LiNO3, LiOH, Li2SO4,
adipic acid, acetylsalicylic acid, salts of benZoic acid,
o-nitrobenZoic acid, p-hydroxybenZoic acid, carbamic
esters, formates, citric acid, citric acid hydrate, chlo
roacetic acid, succinic acid, salts of oxalic acid, oxalic
acid hydrate, tartaric acid, nicotinic acid, nicotinic acid
hydrochloride, maleic acid, malonic acid, DL-mandelic
acid, DL-malic acid, salts of valeric acid, salts of
gluconic acid, salt of cinnamaic acid, salt of acetic acid,
a salt of salicylic acid, trichloroacetic acid, salts of
naphthalene sulfonic acid, hippuric acid, hippuric
esters, salts of phenoxyacetic acid, salts of fumaric
acid, salts of butyric acid;
L-ascorbic acid, glycine, DL-ot-aminoisobutyric acid,
aminobutyric acid, aminopropionic acid, orotic acid
ester salts, DL-valine;
D-glucose, D-glucose hydrate, sucrose, D-mannitol, salts
of glycerophosphoric acid;
18-croWn-6;
catechol, 2-naphthol, m-nitrophenol, hydroquinone,
resorcinol, glycidylglycine, pyrogallol;
acetanilide, acetamide, aniline hydrochloride, ethylenedi
aminetetraacetic acid, caffeine, urea, thiourea, phe
nylenediamine, acrylamide, antipyrine, quinine salts,
cocaine hydrochloride, codeine phosphate dehydrate,
succinimide hydrate, taurine, tetraethyl ammonium
salts, tetrapropylammonium salts, tetramethylammo
RbBr, RbCl, RbClO3, RbC1O4, Rb2CrO4, Rb2Cr2O7, RbI,
RbNO3, Rb2SO4, SbC13,
SeO2,
SmCl3,
nium salts, tris(hydroxymethyl)aminomethane, pyra
Zole, pteridine, and hexamethylenetetramine.
9. The polishing slurry according to claim 1, Wherein said
dispersion medium is;
(1) an acidic solution containing at least one acid selected
from hydro?uoric acid, hydrochloric acid, sulfuric acid,
nitric acid, acetic acid and organic acids;
(2) an alkaline solution containing at least one base
selected from ammonium hydroxide, potassium
hydroxide, sodium hydroxide and amines;
(3) a solution containing a salt of the above acid With the
above base;
(4) Water; or
ZnBr2, ZnCl2, Zn(ClO2)2, Zn(ClO3)2, Zn(ClO4)2, ZnI2,
Zn(NO3)2, and ZnSO4.
4. Apolishing slurry comprising a dispersion medium and
abrasive grains dispersed in the dispersion medium;
said abrasive grains are comprised of organic material.
5. The polishing slurry according to claim 4, Wherein said
organic material has a solubility in the dispersion medium at
25° C., of 0.001 g/100 g or higher.
6. The polishing slurry according to claim 4, Wherein said
organic material has a melting point of 30° C. or above.
7. The polishing slurry according to claim 4, Wherein said
organic material is at least one of;
organic acids, organic acid esters, organic acid salts,
alcohol compounds, ether compounds, phenolic com
pounds and nitrogen-containing compounds.
8. The polishing slurry according to claim 4, Wherein said
organic material is at least one of;
(5) an organic solvent.
10. The polishing slurry according to claim 4, Wherein
said dispersion medium is;
(1) an acidic solution containing at least one acid selected
from hydro?uoric acid, hydrochloric acid, sulfuric acid,
nitric acid, acetic acid and organic acids;
(2) an alkaline solution containing at least one base
selected from ammonium hydroxide, potassium
hydroxide, sodium hydroxide and amines;
(3) a solution containing a salt of the above acid With the
above base;
(4) Water; or
(5) an organic solvent.
11. The polishing slurry according to claim 9, Wherein
said dispersion medium further contains hydrogen peroxide
and ammonium ?uoride.
Jan. 10, 2002
US 2002/0004360 A1
12. The polishing slurry according to claim 10, wherein
said dispersion medium further contains hydrogen peroxide
the dispersion medium so as to vary the quantity of disper
and ammonium ?uoride.
slurry in the form of a solid.
13. The polishing slurry according to claim 1, Wherein
said dispersion medium further contains at least one of
cationic surface-active agents, anionic surface-active agents,
sion of the abrasive grains to be dispersed in the polishing
18. The polishing method according to claim 16, Wherein
the solubility of the abrasive grains in the dispersion
medium is varied by changing the temperature of the pol
amphoteric surface-active agents and organic solvents.
14. The polishing slurry according to claim 4, Wherein
ishing slurry so as to vary the quantity of dispersion of the
said dispersion medium further contains at least one of
form of a solid.
cationic surface-active agents, anionic surface-active agents,
19. A process for fabricating a semiconductor device,
comprising the step of forming a thin ?lm on a semicon
ductor substrate and polishing a surface of said thin ?lm,
amphoteric surface-active agents and organic solvents.
15. A polishing method of polishing a semiconductor
substrate by using a polishing slurry comprising a dispersion
medium and abrasive grains dispersed in the dispersion
medium;
said abrasive grains being comprised of a material having
a solubility in the dispersion medium at 25° C., of 0.001
g/100 g or higher.
16. A polishing method by using a polishing slurry,
Wherein said polishing slurry comprises a dispersion
medium and abrasive grains dispersed in the dispersion
medium so as to vary the quantity of dispersion of the
abrasive grains in the course of polishing.
17. The polishing method according to claim 16, Wherein
said abrasive grains in part are dissolved or precipitated in
abrasive grains to be dispersed in the plishing slurry in the
Wherein the surface of said thin ?lm is polished by using
a polishing slurry comprising a dispersion medium and
abrasive grains dispersed in the dispersion medium,
said abrasive grains being comprised of a material
having a solubitily in the dispersion medium at 25° C.,
of 0.001 g/100 g or higher.
20. The process for fabricating a semiconductor device
according to claim 4 or 5, compring the steps of forming a
thin ?lm on a semiconductor substrate and polishing a
surface of said thin ?lm, Wherein said polishing is carried
out by the polishing method according to claim 15 or 16.
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