KR20130048245A - Carrier fluids for abrasives - Google Patents

Abstract

The present invention relates to an improved novel abrasive carrier fluid, in particular cutting fluid, for the manufacture of a wafer. The present invention also relates to the use of such fluids and wafer cutting methods.

Description

Carrier fluid for abrasives {CARRIER FLUIDS FOR ABRASIVES}

The present invention relates to a carrier fluid for abrasives, to a novel abrasive carrier fluid, in particular to the use of modified polyglycols for the production of cutting fluids, to the removal of materials, in particular to the use of carrier fluids in the cutting of wafers and also to cutting fluids. It relates to a wafer manufactured with the help of.

An abrasive, also known as a grinding or abrasive material, is the grain of the material, preferably a hard material, used for the removal of the material. The use of abrasives as dispersions in fluids, for example grinding fluids or cutting fluids, is known. Abrasives can be used in this way to polish wafers, for example silicon wafers, and also to polish plastics, for example plastics for lenses. The use of abrasives in cutting fluids for cutting wafers is also known. Wafers are thin slices of semiconductors used for example in photovoltaic cells. Electronic components, in particular integrated circuits, can be manufactured from wafers. Wafers generally comprise a brittle material, for example silicon, but may also be made of potassium arsenide or cadmium telluride and the like. Wafers are generally made from cylindrical or cubic single crystals or polycrystals, which are sawed into individual slices, ie wafers. Sawing (also called cutting or lapping) is an industrial practice performed by wire sawing. This is a split method that uses thin wires as cutting material and uses unconstrained cutting grains in the carrier fluid. The diameter of the wire is generally 80 to 180 μm. It is immersed in the slurry of the carrier fluid and the cutting grain and draws the cutting grain attached to the wire surface into the saw cutting. An object / silicon block known as an ingot, which is to be sawed / wrapped, is cut into the wafer by the cutting grain, at which time the particles are removed from the solid to be cut. The carrier fluid for the cutting grain is applied to the slurry together with the cutting grain through an infiltration bath through which the wire penetrates, or generally through a nozzle. The carrier fluid must, in particular, carry out the task of carrying out the attachment of the cutting grain to the wire and carrying the particles of material removed from the solid to be divided. In addition, the carrier fluid must perform the task of providing cooling and transportation of the ground material through saw cutting.

A method of dividing a workpiece, eg a wafer, by wire sawing is known from EP 1 757 419 A1; Here, a slurry applied to the wire is used and the water content of at least a portion of the gas medium around the slurry is adjusted or controlled. In addition, the use of glycols as carrier materials is known from EP 1 757 419 A1.

The use of the cutting oil composition for a) polyether compounds and b) cutting oils comprising silica particles, and ingot cutting with wire saws, in particular silicon ingot cutting, is known from DE 199 83 092 B4 and US 6,383,991 B1. It is.

Aqueous lubricants based on polyethers are known from EP 0 131 657 A1 and US-A-4,828,735. Cutting fluids are likewise known from Chinese patent application CN 101205498 A; There is no decrease in water absorption here. Specifically mentioned compounds are polyalkyleneoxy compounds, which are etherified with alcohols having 1 to 4 carbon atoms.

EP 686 684 A1 discloses a sawing suspension comprising an abrasive material in an aqueous phase comprising at least one water soluble polymer as a thickener. US 2007/0010406 A1 discloses hydroxy polyethers as additives for aqueous cutting fluids which can in particular be used for the production of silicon wafers.

Known cutting fluids are generally based on aqueous or water soluble bases. However, the presence of water is disadvantageous because the presence of water can cause corrosion and also hydrogen can be generated in the cutting of the silicon wafer, for example due to the reaction of water and silicon. A further problem here is that silicate or polysilicate formation takes place on the wafer and in the slurry.

Known water soluble systems may also include water, and the same drawbacks as they occur in aqueous systems may arise because of their microscopic nature attracting water.

It is an object of the present invention to provide an improved abrasive carrier fluid, in particular a cutting fluid, which in particular leads to a reduction in water absorption and a reduction in the energy required for sawing.

The present invention provides the use of a compound of formula (I) for the production of a carrier fluid for abrasives, in particular cutting fluids, with reduced water absorption in the removal of material by the wire saw, in particular sawing of the wafer.

<Formula I>

Where

R ¹ is z is an alkyl radical having 1 to 20 carbon atoms,

(EO) is an ethyleneoxy radical,

(AO) is an alkyleneoxy radical having 3 to 10 carbon atoms,

x is an integer from 3 to 12, in particular from 5 to 10,

y is an integer from 0 to 10, in particular from 4 to 8,

z is an integer from 1 to 6, in particular from 1 to 3.

The present invention further provides an abrasive carrier fluid, in particular a cutting fluid, comprising at least one compound of the formula (I).

<Formula I>

Where

R ¹ is z is an alkyl radical having 5 to 10 carbon atoms,

(EO) is an ethyleneoxy radical,

(AO) is an alkyleneoxy radical having 3 to 10 carbon atoms,

x is an integer from 3 to 12, in particular from 5 to 10,

y is an integer from 0.5 to 10, in particular from 4 to 8,

z is an integer from 1 to 6, in particular from 1 to 3.

The present invention further provides novel compounds of formula II.

&Lt;

Where

R ¹ is 2-methylbutyl or 3-methylbutyl,

(EO) is an ethyleneoxy radical,

(AO) is an alkyleneoxy radical having 3 to 10 carbon atoms,

x is an integer from 3 to 12, in particular from 5 to 10,

y is an integer from 0 to 10, in particular from 4 to 8,

z is an integer from 1 to 6, in particular from 1 to 3.

There are at least as many EO units as are present in the preferred compounds of formula (II). Very particularly preferred compounds of formula (II) are shown in the table below:

In a preferred embodiment, the ratio of x to y in the compounds of formulas (I) and (II) is 1 or less than 1.

For the purposes of the present invention, compounds of formula (II) are particularly preferred embodiments of compounds of formula (I).

In a preferred embodiment,

In formula (I): R ¹ is a pentyl radical, preferably

H ₃ C-CHCH ₃ -CH ₂ -CH _2- (3-methylbutyl) and

And (2-methylbutyl), particularly 3-methylbutyl or more _{10%, - H 3 C-} CH 2 -CHCH 3 -CH 2

In Formulas I and II: AO is propyleneoxy, butyleneoxy and pentyleneoxy or mixtures thereof.

For compounds of formulas (I) and (II), the repeat units (EO) and (AO) may exist as blocks or randomly distribute. In a preferred embodiment, they are randomly distributed. The inventors have surprisingly found that when the random distribution of repeating units (AO) and (EO) is distributed, the viscosity of the compound is highly dependent on temperature. In particular, where the repeating units (EO) and (AO) are randomly distributed, the compounds of formula (I) used according to the invention are prepared from Carborex (Washington Mills AS, N0-7300 Orkanger, Norway). Carborex) The viscosity index in the slurry comprising 40% by weight of silicon carbide of the F 800 PV type is 45% or less, preferably less than 30%, in particular less than 20%, the viscosity index being defined as follows: For which the viscosity index is the percent reduction in the viscosity of the compound of formula (I) at 50 ° C. compared to the viscosity at 30 ° C. Here, the viscosity is the dynamic viscosity (Brookfield, spindle V-73) measured according to DIN EN 12092.

Carrier fluids of the present invention may include not only one compound of formula (I), but also mixtures of compounds of formula (I).

The preparation of compounds of formula (I) is known per se (see, eg, Nonionic Surfactants, edited by Martin J. Schick, Volume 2, Chapter 4 (Marcel Dekker, Inc., New York 1967)). The preparation of the novel compounds of formula II can be carried out in a similar manner.

In a preferred embodiment, the carrier fluid, especially the cutting fluid, for the abrasive consists of the compound of formula (I). The molecular weight of the compound of formula (I) is preferably 200 to 1200 g / mol. In a further preferred embodiment, in addition to the compounds of the formula (I), alkylene alcohols based on ethylene oxide, propylene oxide or copolymers of ethylene oxide and propylene oxide, preferably having a molecular weight of 200 to 800 g / mol, are included. When used for sawing, the cutting fluid comprises an abrasive, in particular cutting grain, in addition to the compound of formula (I).

In a further preferred embodiment, the carrier fluid, in particular the cutting fluid, for the abrasive is at least one further additive, in particular at least one

Monoalkylene glycols, oligoalkylene glycols or polyalkylene glycols,

Humectant,

Thickener,

Dispersant,

Corrosion inhibitors,

Complexing agents and / or

Other additives such as scale inhibitors

To form a carrier fluid.

It is preferred to add one or more of the following additives in the following weight parts per 100 parts by weight of the compound of formula (I):

Alkylene glycols: 10 to 90, in particular 20 to 60 parts by weight,

Humectant: 1 to 100, in particular 10 to 40 parts by weight,

Thickener: 0.5 to 20, in particular 1 to 10 parts by weight,

Dispersant: 0.1 to 20, in particular 0.5 to 10 parts by weight,

Corrosion inhibitors: 0.1 to 10, in particular 0.1 to 3 parts by weight,

Complexing agent: 0.1 to 10, in particular 1 to 5 parts by weight,

Other additives: 0.05 to 10, in particular 0.1 to 5 parts by weight.

The water content of the compositions according to the invention is, based on the total composition, up to 10% by weight, preferably up to 5% by weight, in particular less than 1% by weight.

Particularly preferred additives are shown below:

Wetting agent

In addition to the compounds of the formula (I) used according to the invention, it is possible to use further wetting agents, in particular further wetting agents as follows.

(1) a) sorbitan esters such as poly (oxyethylene) sorbitan monolaurate, poly (oxyethylene) sorbitan monooleate, poly (oxyethylene) sorbitan trioleate

b) fatty amines such as tallow amino ethoxylate, soy amino ethoxylate,

c) castor oil, for example castor oil ethoxylate,

d) alkanolamides, for example coconut oil alkanolamide ethoxylates,

e) fatty acids such as oleic ethoxylate, lauric ethoxylate, palmitic ethoxylate,

f) fatty alcohols,

g) linear alcohol ethoxylates, nonylphenol ethoxylates, octylphenol ethoxylates

Poly (oxyalkylene) derivatives of

(2) hydrophilic polydimethylsiloxane

a) poly (dimethyl) siloxane substituted with one or more carbonyl end groups,

Poly (dimethyl) siloxane copolymer,

c) poly (dimethylsiloxane) -b-poly (propylene oxide) -b-poly (ethylene oxide) copolymer,

d) multiquaternary (dimethylsiloxane) copolymers

(3) fatty imidazolines

(4) a) phosphate,

b) sorbitan,

c) glycerol compounds, for example

Glyceryl monooleate, glyceryl dioleate, glyceryl trioleate, glyceryl dilaurate,

e) sulfosuccinic acid

Fatty acid esters

(5) quaternary compounds, for example

Quaternary ammonium methosulfate.

Further suitable nonionic, cationic, anionic or amphoteric wetting agents are in particular as follows.

Alkoxylated C ₄ -C ₂₂ -alcohols such as fatty alcohol alkoxylates or oxo alcohol alkoxylates. It may be alkoxylated with ethylene oxide, propylene oxide and / or butylene oxide. All alkoxylated alcohols to which at least one of the aforementioned alkylene oxides of at least two molecules have been added may be used as wetting agent. Possible compounds of this type are block polymers of ethylene oxide, propylene oxide and / or butylene oxide or addition products comprising the abovementioned alkylene oxides randomly or in block distribution. Nonionic wetting agents generally comprise 2 to 50 mol, preferably 3 to 20 mol, of one or more alkylene oxides per mole of alcohol. The alcohol preferably has 10 to 18 carbon atoms. Depending on the type of alkoxylation catalyst used in the preparation, the preparation method and the work-up, the alkoxylates have a wide or narrow distribution of the following alkylene oxide analogs:

Alkylphenol alkoxylates such as alkylphenol ethoxylates having C ₆ -C ₁₄ -alkyl chains and 5 to 30 alkylene oxide units;

Alkyl polyglucosides, sorbents having 8 to 22, preferably 10 to 18 carbon atoms in the alkyl chain and generally having 1 to 20, preferably 1.1 to 5 glucoside units Non-alkanoate (also alkoxylated);

Alkoxylated block copolymers of N-alkylglucamides, fatty acid alkoxylates, fatty acid amine alkoxylates, fatty acid amide alkoxylates, fatty acid alkanolamide alkoxylates, ethylene oxide, propylene oxide and / or butylene oxide , Polyisobutene ethoxylates, polyisobutene-maleic anhydride derivatives, optionally alkoxylated monoglycerides, glyceryl monostearate, sorbitan esters and bisglycerides.

Particularly useful nonionic wetting agents are, for example, DE-A 102 43 363, DE-A 102 43 361, DE-A 102 43 360, DE-A 102 43 365, DE-A 102 43 366 , Mixtures of alkyl alkoxylates or alkyl alkoxylates as described in DE-A 102 43 362 or DE-A 43 25 237. It is an alkoxylation product or a mixture of alkoxylation products obtained by reaction of alkanol and alkylene oxide in the presence of an alkoxylation catalyst. Particularly suitable starting alcohols are Guerbet alcohols, in particular ethylhexanol, propylheptanol and butyloctanol. Propylheptanol is particularly preferred. Preferred alkylene oxides are propylene oxide and ethylene oxide, and alkyl alkoxylates preferably form a direct bond between the short polypropylene oxide block and the starting alcohol, as described, for example, in DE-A 102 43 365. Which is particularly preferred because of their low residual alcohol content and their good biodegradability.

A preferred class of suitable nonionic wetting agents are alcohol alkoxylates of formula NI:

<Formula NI>

Where

R ¹ is at least single branched C _{4 -22} -alkyl or _-alkylphenol ,

R ₂ is C _{3 -4} - alkyl,

R ₅ is C _{1 -4} - alkyl,

R ₆ is methyl or ethyl,

n is an average of 1 to 50,

m is an average value of 0-20, preferably 0.5-20,

r is an average value of 0 to 50,

s is an average value of 0-50,

Wherein if R ⁵ is methyl or ethyl or r is 0 then n is at least 0.5.

20 to 95% by weight, preferably from 30 to 95% 1 The above-mentioned alkyl alkoxylate and 5 to 80% by weight or more species of the weight, preferably 5 to 70% by weight, but R ¹ is the same number of carbon atoms Also possible are mixtures of the corresponding alcohol alkoxylates, which are unbranched alkyl radicals of. Also suitable are alcohol alkoxylates of the formula NII.

<Formula NII>

Where

R ³ is branched or unbranched C _{4 -22} -alkyl or _-alkylphenol ,

Alkyl, - R ⁴ is C _{3 -4}

p is an average value of 1-50, preferably 4-15,

q is 0.5-20, Preferably it is 0.5-4, More preferably, it is an average value of 0.5-2.

5 to 95% by weight of one or more branched alcohol alkoxylates of the above-described formula NII and corresponding alcohol alkoxylates in which 5 to 95% by weight of unbranched alkyl radicals are present instead of branched alkyl radicals. Mixtures of are also possible.

In alcohol alkoxylates of the formula NI, R ² is preferably propyl, in particular n-propyl.

In the alcohol alkoxylates of the formula NII, n preferably has an average value of 4 to 15, particularly preferably 6 to 12, especially 7 to 10.

m preferably has an average value of 0.5 to 4, particularly preferably 0.5 to 2, in particular 1 to 2.

An alkyl radical - the radical R ¹ has at least one branched, preferably C _{8 -15} -, especially preferably C _8-13 -, particularly C _{8 -12.} It is also possible for a plurality of branches to exist.

R ⁵ is preferably methyl or ethyl, especially methyl.

R ⁶ is preferably ethyl.

There are compounds with unbranched and branched alcohol radicals R ¹ in the mixture. This is the case, for example, with oxo alcohols having a proportion of linear alcohol chains and a proportion of branched alcohol chains. For example, C _13/15 oxo alcohol is frequently a complete linear chain alcohol of about 60% by weight of α- methyl about 40% by weight - has a branched alcohol with chain-branched and C _≥2.

In the alcohol alkoxylates of formula NII, R ³ is preferably a branched or unbranched C _{8 -15} - alkyl radical, particularly preferably a branched or unbranched C _{8 -13} - alkyl radical, in particular branched or unbranched branched C _{8 -12} - an alkyl radical. R ⁴ is preferably propyl, in particular n-propyl. p preferably has an average value of 4 to 15, particularly preferably an average value of 6 to 12, in particular an average value of 7 to 10. q preferably has an average value of 0.5 to 4, particularly preferably 0.5 to 2, in particular 1 to 2.

In a similar manner to the alcohol alkoxylates of formula NI, alcohol alkoxylates of formula NII may also be present as a mixture with unbranched and branched alcohol radicals.

Possible alcohol components on which alcohol alkoxylates are based include not only pure alkanols but also analogue mixtures having a range of carbon atoms. Examples of C _8/10 - there is an alkanol-alkanol, C _10/12 - alkanol, C _13/15 - alkanol, C _12/15. Mixtures of a plurality of alkanols are also possible.

According to the invention the alkanol alkoxylate or mixture is preferably optionally in the first _{3 -6} C a mixture of alcohol, or the corresponding branched and unbranched alcohols of the formula R ¹ -OH or R ³ -OH - alkylene oxide and subsequently optionally with C _{3 -4} ethylene oxide and subsequently - is prepared by reacting an alkylene oxide-alkylene oxide and then the appropriate C _{5 -6.} The alkoxylation is preferably carried out in the presence of an alkoxylation catalyst. In particular, basic catalysts such as potassium hydroxide are used here. The random distribution of incorporated alkylene oxide amounts can be greatly limited by certain alkoxylation catalysts, such as modified bentonite or hydrotalcite, as described, for example, in WO 95/04024. Alkoxylates in the range "are obtained.

In certain embodiments of the invention, the alkoxylate is an alkoxylate mixture comprising an alkoxylate of the formula NIII:

<Formula NIII>

Where

A is ethyleneoxy,

Radicals B are each independently of the other C _{3 -10-alkyleneoxy,} preferably propyleneoxy, oxy-butylene, pentylene, or oxy, and mixtures thereof,

Wherein groups A and B are present in the order shown in block form,

p is 0 to 10,

n is greater than 0 and 20,

m is greater than 0 and 20,

q is greater than 0 and 10,

p + n + m + q is 1 or more,

here

70 to 99% by weight of alkoxylate A1 wherein C ₅ H ₁₁ is nC ₅ H ₁₁ and

1 to 30% by weight of alkoxylates A2 wherein C ₅ H ₁₁ is C ₂ H ₅ CH (CH ₃ ) CH ₂ and / or CH ₃ CH (CH ₃ ) CH ₂ CH ₂ are present in the mixture.

In formula (NIII), p is 0-10, preferably 0-5, in particular 0-3. If block (B) _p is present, p is preferably 0.1 to 10, particularly preferably 0.5 to 5, in particular 1 to 3.

In formula (NIII), n is preferably in the range from 0.25 to 10, in particular from 0.5 to 7, and m is preferably in the range from 2 to 10, in particular from 3 to 6. B is preferably propyleneoxy and / or butyleneoxy, in particular propyleneoxy at both positions.

q is preferably in the range of 1 to 5, particularly preferably in the range of 2 to 3.

The sum of p + n + m + q is at least 1, preferably 3 to 25, particularly preferably 5 to 15, in particular 7 to 13.

It is preferred that three or four alkylene oxide blocks are present in the alkoxylates. In one embodiment, first ethyleneoxy units, then propylene oxide units, and then ethyleneoxy units are adjacent to the alcohol radicals. In a further embodiment, first the propyleneoxy units, then the ethyleneoxy units, then the propyleneoxy units, and finally the ethyleneoxy units are adjacent to the alcohol radicals. It is also possible for the other alkyleneoxy units shown to be present instead of propyleneoxy units.

p, n, m and q are the average values for the alkoxylates, respectively. For this reason, p, n, m and q may have non-integer values. Alkoxylation of alkanols generally provides a distribution of the degree of alkoxylation, which can be set to some extent by the use of different alkoxylation catalysts. The selection of appropriate amounts of groups A and B enables the characteristic spectrum of the alkoxylate mixtures according to the invention to meet practical requirements.

The alkoxylate mixture is obtained by alkoxylation of the parent alcohol C ₅ H ₁₁ CH (C ₃ H ₇ ) CH ₂ OH. The starting alcohol can be mixed from the individual components to give a ratio according to the invention. It can be prepared by aldol condensation of valericaldehyde and subsequent hydrogenation. The preparation of valeraldehyde and the corresponding isomers are described, for example, in US 4,287,370; It is performed by hydroformylation of butenes, as described in Beilstein E IV 1, 32 68, Ullmanns Encyclopedia of Industrial Chemistry, 5th Edition, Volume A1, pages 323 and 328 ff. Subsequent aldol condensation is described, for example, in US Pat. No. 5,434,313 and in Roempp, Chemie Lexikon, 9th Edition, keyword "Aldol-Addition", page 91. Hydrogenation of the aldol condensation product follows general hydrogenation conditions.

In addition, 2-propylheptanol can be prepared by condensation of 1-pentanol (as a mixture of corresponding 1-methylbutanol) in the presence of KOH at elevated temperature (see, for example, Marcel Guerbet, CR Acad Sci). Paris 128, 511, 1002 (1899). See also Roempp, Chemie Lexikon, 9th Edition, Georg Thieme Verlag Stuttgart and references cited therein and also Tetrahedron, Vol. 23, pages 1723 to 1733.

In formula (NIII), the radical C ₅ H ₁₁ may be nC ₅ H ₁₁ , C ₂ H ₅ CH (CH ₃ ) CH ₂ or CH ₃ CH (CH ₃ ) CH ₂ CH ₂ . Alkoxylates

70-99% by weight, preferably 85-96% by weight, of alkoxylate A1, wherein C ₅ H ₁₁ is nC ₅ H ₁₁

1 to 30% by weight, preferably 4 to 15% by weight of alkoxylates A2, wherein C ₅ H ₁₁ is C ₂ H ₅ CH (CH ₃ ) CH ₂ and / or CH ₃ CH (CH ₃ ) CH ₂ CH ₂ % Present

Mixture.

The radical C ₃ H ₇ is preferably nC ₃ H ₇ .

The alkoxylates may also be block isotridecanol alkoxylates of the formula NV.

<Formula NV>

In the above formula.

R is an isotridecyl radical,

m is 2 and n is 3 or 4

m is 3 or 4 while n is 2

x and y are 1 to 20 independently of each other,

Where m = 2 / n = 3 or 4, the variable x is greater than or equal to y.

Block isotridecanol alkoxylates are described, for example, in DE 196 21 843 A1.

Another suitable class of nonionic surfactants are the end-capped alcohol alkoxylates, in particular of the alcohol alkoxylates mentioned above. In certain embodiments, the end-capped alcohol alkoxylates are end-capped alcohol alkoxylates corresponding to alcohol alkoxylates of the formulas NI, NII, NIII, and NV. End caps, for example, dialkyl sulfates, C _{1 -10} - alkyl halide, C _{1 -10} - phenyl halide, preferably a chloride, bromide, most preferably cyclohexyl chloride, cyclohexyl bromide, phenyl chloride, or It may be prepared by phenyl bromide.

Examples of end-capped alkoxylates are also disclosed in DE-A 37 26 121, the entire relevant disclosure of which is incorporated herein by reference. In a preferred embodiment, the alcohol alkoxylate has the structure of formula NVI.

<Formula NVI>

Where

R ^I is hydrogen or C ₁ -C ₂₀ -alkyl,

R ^II and R ^III are the same or different and are each independently hydrogen, methyl or ethyl,

R ^IV is C ₁ -C ₁₀ -alkyl, preferably C ₁ -C ₄ -alkyl, or cyclohexyl or phenyl,

m 'and n' are the same or different and are each greater than or equal to 0,

The sum of m 'and n' is 3 to 300.

Another class of nonionic wetting agents are alkyl polyglucosides with preferably 6 to 22, particularly preferably 10 to 18, carbon atoms in the alkyl chain. The compound generally comprises 1 to 20, preferably 1.1 to 5 glucoside units.

Further nonionic wetting agents are end-capped fatty acid amide alkoxylates of the formulas known from WO-A 95/11225.

Where

R ^I is a C ₅ -C ₂₁ -alkyl or alkenyl radical,

R ² is a C ₁ -C ₄ -alkyl group,

A ¹ is C ₂ -C ₄ -alkylene,

y is 2 or 3,

x is 1-6.

Examples of such compounds include the reaction products of n-butyl triglycolamine of the formula H ₂ N- (CH ₂ -CH ₂ -O) ₃ -C ₄ H ₉ and methyl dodecanoate or of the formula H ₂ N- (CH _2- CH ₂ -O) is the reaction product of a commercial mixture of ethyl tetraglycolamine of ₄ -C ₂ H ₅ with saturated C ₈ -C ₁₈ methyl fatty acid ester.

Further suitable nonionic wetting agents are polyhydroxy or polyalkoxy fatty acid derivatives such as polyhydroxy fatty acid amides, N-alkoxy or N-aryloxy polyhydroxy fatty acid amides, fatty acid amide ethoxylates, in particular end-capped fatty acid amides. Toxylates, and also fatty acid alkanolamide alkoxylates.

Further suitable nonionic wetting agents are block copolymers of ethylene oxide, propylene oxide and / or butylene oxide (Pluronic® and Tetronic from BASF SE and BASF Corp.) ^. A) ^? Grade). In a preferred embodiment, the copolymer is a polyethylene / polypropylene / polyethylene block and a triblock copolymer having a molecular weight of 4000 to 16,000, wherein the weight ratio of the polyethylene blocks is 55 to 90% based on the triblock copolymer. Particular preference is given to triblock copolymers having a molecular weight greater than 8000 and a polyethylene content of 60 to 85% by weight, based on the triblock copolymer. Said preferred triblock copolymers are in particular sold under the trade names Pluronic F127, Pluronic F108 and Pluronic F98 from BASF Corporation in each case, and WO 01/47472 A2, the entire relevant disclosure of which is incorporated herein by reference. It is described in the issue.

It is also preferred to use block copolymers of ethylene oxide, propylene oxide and / or butylene oxide capped at one or both ends. Capping at one end is achieved using, for example, an alcohol, in particular a C _{1 -22} -alkyl alcohol, for example methanol, as starting compound for reaction with alkylene oxide. In addition, both ends form end-capping, for example, a free block copolymer dialkyl sulfate, C _{1 -10} - alkyl halide, C _{1 -10} - phenyl halide, preferably a chloride, bromide, and particularly preferably a cycloalkyl It can be produced by reacting with hexyl chloride, cyclohexyl bromide, phenyl chloride or phenyl bromide.

Individual nonionic wetting agents or combinations of different nonionic surfactants may also be used. It is possible to use nonionic wetting agents from only one class, in particular only alkoxylated C ₄ -C ₂₂ -alcohols. As an alternative, however, wetting agent mixtures from various classes can also be used.

The concentration of nonionic wetting agent in the composition according to the invention can vary depending on the leaching conditions, in particular on the material to be leached.

Suitable anionic wetting agents include alkanesulfonates such as C ₈ -C _24- , preferably C ₁₀ -C ₁₈ -alkanesulfonates, and also soaps, such as saturated and / or unsaturated C ₈ -C ₂₄ -carboxylic acids. Na and K salts.

Further suitable anionic wetting agents are linear C ₈ -C ₂₀ -alkylbenzenesulfonates (“LAS”), preferably linear C ₉ -C ₁₃ -alkylbenzenesulfonates and -alkyltoluenesulfonates.

Thickener

Thickeners are compounds that increase the viscosity of a chemical composition. Non-limiting examples are provided, for example, in WO 2009/090169 A1: polyacrylates and hydrophobically modified polyacrylates. The advantage of using thickeners is that liquids with relatively high viscosities have longer residence times on sloped or vertical surfaces than liquids with lower viscosities. This increases the interaction time between the composition and the surface.

Further particularly preferred thickeners are, for example, bentonite, xanthan and cellulose and also cellulose derivatives, in particular cellulose ethers and cellulose esters, in particular methylcellulose, hydroxyethylcellulose and carboxymethylcellulose. Further examples of thickeners are polyacrylamides, polyether or associative polyurethane thickeners, polyvinyl alcohol and polyvinylpyrrolidone.

Dispersant Scale inhibitors

It is also possible according to the invention to further use at least one dispersant, for example selected from the group consisting of condensation products of naphthalenesulfonic acid salts, naphthalenesulfonic acid and formaldehyde and also polycarboxylates. Dispersants of this type are, for example, available from BASF SE under the trade name Tamol ^? , Sokalan ^? And Necal ^? Under the trade name Solsperse ® from Lubrizol ^. It is marketed under. The dispersant may also act as a scale inhibitor (anti-deposition agent) because it disperses calcium carbonate CaCO ₃ formed in the alkaline medium and thus prevents, for example, clogging of the nozzle or formation of deposits in the pipe. Independently of this, the composition according to the invention may further comprise one or more additional scale inhibitors. Suitable scale inhibitors are described, for example, in WO 04/099092, wherein

(a) from 50 to 80% by weight, preferably from 50 to 75% by weight, particularly preferably from 55 to 70% by weight of a poly (meth) acrylic acid backbone,

(b) 1 to 40% by weight, preferably 5 to 20% by weight, particularly preferably 7 to 15% by weight, selected from the group consisting of isobutene units, tereractone units and isopropanol units and bonded to the backbone / One or more units, incorporated into the skeleton, and

(c) 5 to 50% by weight, preferably 5 to 40% by weight, particularly preferably 10 to 30% by weight, of aminoalkylsulfonic acid based amide units

Wherein a (meth) acrylic acid copolymer is described wherein the total weight of units in the (meth) acrylic acid copolymer is 100% by weight and all weight percentages are based on the (meth) acrylic acid copolymer.

The (meth) acrylic acid copolymers provided according to WO 04/099092 have a weight average molecular weight of 1000 to 20,000 g / mol of the polymer comprising sulfone groups and can preferably be prepared by the following process steps:

(1) free radical polymerization of isopropanol and optionally (meth) acrylic acid in the presence of water, to produce polymer I, and

(2) Amidation by Reaction of Polymer I with at least one aminoalkanesulfonic acid from Process Step (1).

Further suitable scale inhibitors are, for example:

Semiamides of polycarboxylic acids obtainable by reaction of polymers comprising anhydride groups with compounds comprising amino groups (described in DE 195 48 318).

Vinyllactic acid and / or isopropenyllactic acid (as described in DE 197 19 516),

Homopolymers of acrylic acid (described in US-A-3 756 257),

Copolymers of acrylic acid and / or (meth) acrylic acid and vinyllactic acid and / or isopropenyllactic acid,

Copolymers of styrene and vinyl lactic acid,

Copolymers of maleic acid and acrylic acid,

(I) at least one monoethylenically unsaturated monomer,

  (II) polymers of monoethylenically unsaturated dicarboxylic acids or their anhydrides having a molar mass of 200 to 5000 g / mol

Can be obtained by free radical initiated graft polymerization of

  (III) 5 to 20,000 parts by weight of (I) is used per 100 parts by weight of the graft base (II),

Water soluble or water dispersible graft polymer (DE 195 03 546),

Optionally hydrolyzed polymaleic anhydride and salts thereof (described in US-A-3 810 834, GB-A-1 454 657 and EP-A-0 261 589),

Iminodisuccinate (described in DE 101 02 209),

Formulations comprising complexing agents such as ethylenediaminetetraacetic acid (EDTA) and / or diethylenetriaminepentaacetic acid (DTPA) (described in US 5,366,016),

Phosphonates,

Polyacrylates,

Polyaspartic acid or polyaspartic acid modified as described in DE-A-44 34 463,

Polyaspartimide,

Polymers comprising hydroxamic acid, hydrosam ether and / or hydrazide groups (described in DE 44 27 630),

Optionally hydrolyzed polymer of maleimide (described in DE 43 42 930),

Naphthylamine polycarboxylate (described in EP 0 538 969),

Oxaalkanepolyphosphonic acid (described in EP 330 075),

Polyhydroxyalkaneaminobismethylenephosphonic acid (described in DE 40 16 753), and

Oxidized polyglucoic acid (as described in DE 43 30 339)

to be.

Particularly preferred dispersing agents are socalan from polyacrylic acid, for example BASF SE ^. Grades, and polyaspartic acid, in particular β-polyaspartic acid having a molecular weight of 2000 to 10,000 g / mol. Preferred polymeric compounds comprising carboxylic acid groups are the acrylic acid homopolymers shown in EP 2 083 067 A1. They preferably have a number average molecular weight in the range of 1000 to 50,000, particularly preferably 1500 to 20,000. Monopolymers of acrylic acid which are particularly suitable as polymer compounds comprising carboxylic acid groups are sucalane? PA grade.

Further suitable polymeric compounds comprising carboxylic acid groups are oligomaleic acid, as described, for example, in EP-A 451 508 and EP-A 396 303.

Other compounds preferred as polymer compounds comprising carboxylic acid groups are copolymerized copolymers of at least one comonomer B) and at least one unsaturated monocarboxylic or dicarboxylic or dicarboxylic anhydride or salts thereof as monomer A). It is a copolymer included in the form. The monomers A) are preferably C ₃ -C ₁₀ -monocarboxylic acids, salts of C ₃ -C ₁₀ -monocarboxylic acids, C ₄ -C ₈ -dicarboxylic acids, C ₄ -C ₈ -dicars Anhydrides of acids, salts of C ₄ -C ₈ -dicarboxylic acids or mixtures thereof. Monomers A) in salt form are preferably used in the form of their water-soluble salts, in particular alkali metal salts such as potassium and in particular sodium or ammonium salts. Monomer A) may in each case be present in whole or in part in anhydride form. Of course, it is also possible to use mixtures of monomers A).

The monomer (A) is preferably selected from acrylic acid, methacrylic acid, crotonic acid, vinylacetic acid, maleic acid, maleic anhydride, fumaric acid, citraconic acid, citraconic anhydride, itaconic acid and mixtures thereof. Particularly preferred monomers A) are acrylic acid, methacrylic acid, maleic acid, maleic anhydride and mixtures thereof. The copolymer is preferably at least one monomer A in an amount of from 5 to 95% by weight, particularly preferably from 20 to 80% by weight and in particular from 30 to 70% by weight, based on the total weight of the monomers used for the polymerization. In the copolymerized form.

Corrosion inhibitor

For example, the agents shown in WO 2008/071582 A1, for example carboxylic acids, act as corrosion inhibitors. It may be linear or branched. Mixtures of various carboxylic acids may be particularly preferred. Caprylic acid, ethylhexanoic acid, isononanoic acid and isodecanoic acid are particularly preferred carboxylic acids. Because corrosion protection emulsions are frequently neutral to slightly alkaline, it may be advantageous to use the carboxylic acid in at least partially neutralized form, ie as a salt. Sodium hydroxide and / or potassium hydroxide and also alkanolamines are particularly suitable for neutralization. Particular preference is given to using monoalkanolamines and / or trialkanolamines. The use of dialkanolamines is less preferred due to the risk of formation of nitrosamines. The dialkanolamines may be used alone or equally sufficiently for neutralization with monoalkanolamines and / or trialkanolamines.

Suitable corrosion inhibitors, in particular

Aliphatic carboxamides having 14 to 36 carbon atoms such as myristicamide, palmitamide and oleamide; Alkenylsuccinamides having 6 to 36 carbon atoms, such as octenylsuccinamide, dodecenyl succinamide; Mercaptobenzothiazole.

Particularly preferred corrosion inhibitors are alkylene oxide adducts with aliphatic amines, in particular triethanolamine and ethylenediamine adducts with 2 to 8 mol% of propylene oxide.

Complexing agent

Complexing agents are compounds that bind cations. Typical examples include EDTA (N, N, N ', N'-ethylenediaminetetraacetic acid), NTA (N, N, N-nitrilotriacetic acid), MGDA (2-methylglycine-N, N-diacetic acid), GLDA (Glutamic acid diacetate), ASDA (aspartic acid diacetate), IDS (iminodiisuccinate), HEIDA (hydroxyethylimine diacetate), EDDS (ethylenediamine disuccinate), citric acid, oxodisuccinic acid and butanetetra Carboxylic acids and their fully or partially neutralized alkali metal or ammonium salts.

Other additives

Further suitable additives are, for example, binders. Suitable binders are, for example, the amphiphilic water-soluble alkoxylated polyalkyleneimines of formula AI shown in WO 2006/018856 A2.

<Formula AI>

Wherein the variable has the following meaning:

The radicals R are the same or different linear or branched C ₂ -C ₆ -alkylene radicals;

B is branch;

E is an alkyleneoxy unit of the formula:

R ¹ is 1,2-propylene, 1,2-butylene and / or 1,2-isobutylene;

R ² is ethylene;

R ³ is 1,2-propylene;

R ⁴ is hydrogen, C ₁ -C ₄ -alkyl which is the same or different radicals;

x, y, z are 2 to 150, respectively, and the sum of x + y + z is the number of alkyleneimine units and corresponds to the average molecular weight Mw of polyalkyleneimines of 300 to 10,000 prior to the alkoxylation;

m is a free number from 0 to 2;

n is a free number from 6 to 18;

p is a rational number of 3-12, and 0.8 <= n / p <1.0 (x + y + z) 1/2.

The invention further provides a slurry consisting of carrier fluids, in particular cutting fluids, abrasives, in particular grinding and / or cutting grains, and optionally additives.

It is possible to use conventional abrasives, in particular grinding and / or cutting grains, for example metals, metals or semimetals, carbides, nitrides, oxides, borides or diamond grains. Particularly preferred cutting grains are carbide and boride grains, in particular silicon carbide (SiC) grains. The cutting grains preferably have a structure that matches the wafer and the material to be cut. Preferred particle sizes range from 0.5 to 50 μm. Cutting grains may be present in either heterogeneous or homogeneously dispersed form. Cutting grains are preferably included in the cutting fluid composition at a concentration of 25 to 60% by weight, in particular 40 to 50% by weight.

In a particularly preferred embodiment, the carrier fluid, in particular the cutting fluid, has a contact angle with respect to V2A steel of 5-40 °, in particular 10-30 °. Here, the contact angle is measured at 25 ° C. on a steel sheet made of V2A steel rinsed with water and acetone.

In a further preferred embodiment, the carrier fluid of the invention, in particular the cutting fluid, is a stainless steel cylinder M1M6 having a diameter of 12 mm on an MDD2 scale from Hermann Reichert Maschinenbau (Heidenhof Bachnang, Germany). An average weight loss of less than 20-60 mg in 1 minute over two tests over a distance of 110 m at a load of 300 N for / 05R (Torrington).

In a further preferred embodiment, the carrier fluid of the invention, in particular the cutting fluid, is 30% or less, preferably 15% or less after 10 hours storage in a Heraeus BBD 6220 CO ₂ incubator at 38 ° C. and 78% relative atmospheric humidity. Absorb water. For the storage test, 1 g of carrier fluid, in particular cutting fluid, is used in a Petri dish of 60 mm inner diameter in each case. In each case, determine the average of the duplicate measurements. In a very particularly preferred embodiment, the water absorption does not increase even upon further exposure.

The carrier fluid according to the invention, in particular the cutting fluid and the slurry consisting of 40% by weight of the abrasive shown below, in particular grinding and / or cutting grains, uses Carborex BWF 800 PV silicon carbide grains from Washington Mills, Preferably the viscosity measured at 30 ° C. using the Brookfield LVDV-111 Ultra apparatus (Spindle V-73) is 140 to 200 mPas, in particular 150 to 190 mPas.

The invention further relates to a method of cutting an inorganic semiconductor, such as a silicon ingot or a wafer of silicon blocks, by a wire saw, using a slurry based on the cutting fluid and cutting grain of the invention.

The present invention further uses the abrasive dispersed in the carrier fluid used according to the invention to grind or polish the material derived from, for example, silicon ingots or blocks, for example by chemical mechanical polishing (CMP). Or to a method of grinding a polymer, especially a lens polymer.

advantage

The carrier fluid of the invention, in particular the cutting fluid, and the cutting method of the invention are particularly suitable for sawing ingots, blocks or cylinders of monocrystalline or polycrystalline silicon single crystals or polycrystals, GaAs, CdTe and other semiconductors and ceramics.

Carrier fluids, in particular cutting fluids of the invention, show little or no foaming, require no additives, are pH neutral, and non-toxic. In addition, it does not contain any volatile organic components. In addition, the carrier fluids, in particular the cutting fluids of the invention, are very suitable for reworking by the post-treatment of wet chemicals, for example as described in WO 02/40407 A1 and EP 1 390 184 A1.

Example :

General manufacturing method of polyether

1-2 mol of starting alcohol were in each case placed in an anhydrous dry 1 L pressure reactor, mixed with 0.2% by weight (based on final product) of KOH and flushed with nitrogen. The closed reactor was then heated to 130 ° C. over a period of 30 minutes and a gauge pressure of 1 bar was set with nitrogen. While stirring, the molar amount of propylene oxide (hereinafter PO) and ethylene oxide (hereinafter EO) shown in Table 1 was subsequently metered in simultaneously (random method) or continuously (block method). In the block process, after adding PO and reaching a constant pressure, the mixture was stirred at 130 ° C. for at least ½ hour, the pressure was set to 1 bar and then EO was added. The vessel was thermostated to 130 ° C. during the reaction. After reaching a constant pressure, the mixture was stirred for an additional about 1/2 hour. After completion of the reaction, the mixture was cooled to 80 ° C., the reactor was depressurized, flushed with nitrogen, the amount of glacial acetic acid calculated for KOH neutralization was added and the mixture stirred for ½ hour.

OH number was determined according to DIN 51562, residual alcohol content was determined by gas chromatography, and APHA color number was measured according to EN 1557 (at 23 ° C.).

Wetting Agents and Alkylene Glycol Pluronic® Added to Examples C6 and C7? PE 6200 and Pula Pack? LF 401 is commercially available from BASF SE (Ludwigshafen, Germany). The analytical data recorded is based on the pentanol + 1.5 PO + 6 EO component, the block method according to the invention.

Measurement of characteristic / characteristic values

The properties of the cutting fluid according to the invention are outlined in Table 2 below. The following properties were measured:

● water absorption

The water uptake of the cutting fluid was measured after 10 and 24 hours storage in Heraeus BBD 6220 CO ₂ incubator at 38 ° C. and 78% relative atmospheric humidity. For storage, in each case 1 g of cutting fluid was used in a Petri dish with an internal diameter of 60 mm. In each case the average of duplicate measurements was determined. Water absorption was recorded in weight percent increase based on the initial weight in each case.

● slurry viscosity

To measure the slurry viscosity, a mixture of 60% by weight sawing fluid and 40% by weight CarCorex BW F 800 PV type SiC from Washington Mills was prepared and the LVDV-111 Ultra Viscometer (Spindle V-73 from Brookfield) The viscosity was measured at 30 ° C. and optionally 50 ° C. using the model. Slurry viscosity was reported in mPas.

● Contact angle

The contact angle of the cutting fluid was measured at 25 ° C. after 1 second of droplet application on a steel sheet made of V2A steel, which was rinsed with water and acetone and then dried in air for 1 hour. For the measurement, an image-assisted high-speed contact angle measuring device from Dataphysics Instruments GmbH (filderstadt Raijensenstrasse 34, Germany) was used. The unit of contact angle was °.

● wear

The wear behavior was obtained from Hermann Reichscher Maschnenbau (Heidenhof, Baknang, Germany) within 54.5 seconds at a load of 300 N and a test distance of 100 m for a stainless steel cylinder M1M6 / 05R (Torrington) with a diameter of 12 mm. The friction wear balance of MDD2 was measured. In each case duplicate measurements were taken and the average of the weight loss of the cylinder was measured. Weight loss was reported in mg.

Pluriol? E 200 is polyethylene glycol with an average molar mass of 200 from BASF SE (Ludwigshafen, Germany). The above embodiment represents the prior art and is not in accordance with the present invention. Compounds II.1 and II.2 gave results comparable to compounds C2 and C3.

Real exam

A sawing test for polycrystalline silicon blocks was performed on a DS 265 wire saw from Meyer Burger AG (3600 Thun Alemendstrasse 86, Switzerland) using sawing fluids C1 and C3. The test conditions were as follows:

Wafer dimensions: 5 "x 5", 150 μm

SiC grade: F 88, ds50 = 6.5 μm

Advance Speed: 0.6 mm / s

Wire speed: 14 m / s

Wire diameter: 120㎛

Wire tension: 20 N

Slurry temperature: 22 ℃

Slurry Composition: 60 wt% Saw Fluid, 40 wt% SiC

Compared to PEG 200 (Fluriol® E 200) commonly used in industrial practice, the following improvements were found for cutting fluids according to the invention:

Similar improvements were also found with other products according to the invention shown in Table 1.

Claims (15)

Use of a compound of formula (I) for the production of carrier fluids, especially cutting fluids, for abrasives, with reduced water absorption in the removal of material by wire saws, in particular sawing of wafers.
(I)

In this formula,
R ¹ is z is an alkyl radical having 1 to 20 carbon atoms,
(EO) is an ethyleneoxy radical,
(AO) is an alkyleneoxy radical having 3 to 10 carbon atoms,
x is an integer from 3 to 12, in particular from 5 to 10,
y is an integer from 0 to 10, in particular from 4 to 8,
z is an integer from 1 to 6, in particular from 1 to 3. The compound of claim 1 wherein
R ¹ is an alkyl radical, in particular pentyl, z having 5 to 10 carbon atoms. The use according to claim 1 or 2, wherein the contact angle of the cutting fluid to V2A steel at 25 ° C is 25 to 50 °. 4. Use according to any of the preceding claims, wherein the wafer is a semiconductor, in particular silicon. Carrier fluids, in particular cutting fluids, are used in the slurry together with the cutting grains, and metals, carbides, nitrides, metal oxides, borides or diamond grains according to any one of the preceding claims. Use as used as. The method according to any one of claims 1 to 5, wherein during or after the removal of the material, in particular after cutting, the removal of the grinding material produced by work-up of the carrier fluid, in particular the cutting fluid, is carried out. Usage. Carrier fluids, in particular cutting fluids, comprising at least one compound of formula (I)
(I)

In this formula,
R ¹ is z is an alkyl radical having 5 to 10 carbon atoms,
(EO) is an ethyleneoxy radical,
(AO) is an alkyleneoxy radical having 3 to 10 carbon atoms,
x is an integer from 3 to 12, in particular from 5 to 10,
y is an integer from 0.5 to 10, in particular from 4 to 8,
z is an integer from 1 to 6, in particular from 1 to 3. 8. Carrier fluid, in particular cutting fluid, according to claim 7, wherein R ¹ is pentyl. 8. Carrier fluid, in particular cutting fluid, according to claim 7, wherein the contact angle for V2A steel at 25 ° C is 25 to 50 °. The cutting grains, in particular silicon carbide grains, according to any one of claims 1 to 9, for removing material by sawing, from sawing objects, in particular semiconductors, in particular silicon, in particular during sawing of the wafer. Use of carrier fluids, especially cutting fluids. Use of a carrier fluid according to any one of claims 1 to 10 for polishing a material, in particular for the manufacture of silicon or, in particular for lenses, a wafer of a material composed of a polymer. A method of cutting a wafer from an object by a saw using a slurry consisting of cutting fluid and cutting grains, in particular cutting grains consisting of metals, carbides, nitrides, oxides, borides, α-aluminas or diamonds. 12. A method according to any one of claims 1 to 11, wherein during or after the removal of the material, in particular after cutting, optionally aftertreatment, the resulting grinding material is separated off. A method of polishing a material, in particular a material consisting of silicon or a polymer, using a slurry composed of a carrier fluid and an abrasive material, wherein the carrier fluid according to any one of claims 1 to 12 is used as a carrier fluid. A wafer, in particular a silicon wafer, obtained according to any of the preceding claims. A compound of formula II
<Formula II>

In this formula,
R ¹ is 2-methylbutyl or 3-methylbutyl,
(EO), (AO), x and y are as defined in claim 1.