Solution for post-etch residue removal (PERR)

Abstract

The present invention relates to a composition for removing post-etch residues from a substrate comprising a surface of a molybdenum layer, the composition comprising: (a) 10% to 60% by weight of a water-miscible organic solvent; (b) from 4% to 15% by weight of a C1-C12 amine; (c) 0.1% to 4% by weight of a C4 to C16 quaternary ammonium hydroxide; (d) 0.5% to 5% by weight of a C2 to C10 polyol; (e) from 0.01% to 1% by weight of a polyalkoxylated polyethyleneimine; (f) from 0.001% to 0.07% by weight of at least one guanidine derivative selected from the group consisting of 1, 3-diphenylguanidine, 1-(o-tolyl) biguanide, metformin, phenformin, guanine, proguanidine hydrochloride, 2-guanidinobenzimidazole, polyhexamethylene biguanide hydrochloride, polyaminopropyl biguanide, chlorhexidine or a chlorhexidine salt; and (g) water.

Description

[0001] The present invention relates to a composition, its use, and a method for post-etch residue removal (PERR) for a substrate (especially a semiconductor substrate) containing molybdenum. Background Art

[0002] Resists (such as deep UV photoresists or electron beam resists) are used in microlithography for the production of a wide range of electronic devices, such as semiconductor integrated circuits (ICs), liquid crystal panels, organic electroluminescent panels, printed circuit boards, micromachines, DNA chips, and microdevices, especially ICs with LSI (large scale integration) or VLSI (very large scale integration).

[0003] Copper is commonly used as a low-resistance or wiring material in electronic devices (especially in the vias and interconnects contained in ICs). The increasing use of copper and the continuously decreasing size of electronic structures, together with the continuously increasing IC functionality, require the use of low-k materials and ultra-low-k materials in order to avoid problems of wiring resistance and wiring delay caused by high wiring capacitance. These challenging developments have required and still require continuous optimization of manufacturing methods and continuous optimization of the materials used therein.

[0004] Although damascene patterning has to overcome many technical challenges, copper-based interconnects have been applied to many successive technology nodes. As we move towards local BEOL (back-end-of-line) interconnect metal pitches ≤ 20 nm (for N2 and more advanced technology nodes), it has been noted that the resistance of copper metal lines increases very rapidly at such small sizes due to electron scattering at the surface and also at grain boundaries. In addition, copper metal lines require a liner to prevent copper diffusion into the dielectric material. Since this liner requires a fixed thickness to prevent diffusion, scaling the copper interconnect without being able to scale the liner thickness results in a significant relative increase in metal resistance as the critical dimension decreases.

[0005] Two interesting candidates expected to have lower resistance than copper (Cu) at very small sizes are ruthenium (Ru) and molybdenum (Mo). Important advantages of Ru and Mo are that both materials can be patterned by direct metal etching, just as was the case with aluminum (Al) before the Cu interconnect era. In addition, since both Ru and Mo can be integrated without a barrier. Therefore, when integrating Ru or Mo at small sizes, a reduction in resistance can be expected.

[0006] In particular, molybdenum can have many advantages sought in the art. For example, it can be used as a conductor in BEOL or mid-end-of-line (MEOL) applications, or in buried power rails or work function layers in logic applications, and in word lines or bit lines in advanced memory applications.

[0007] For copper, many so-called post-etch residue removal (PERR) processes have been developed and disclosed in the prior art.

[0008] WO 2010 / 127941 A discloses an etch residue removal composition comprising a liquid composition free of N-alkylpyrrolidone and hydroxylamine and hydroxylamine derivatives and comprising at least two polar organic solvents and at least one quaternary ammonium hydroxide, the polar organic solvents being selected from the group consisting of solvents that exhibit a constant removal rate at 50 °C for a 30 nm thick polymer barrier anti-reflection layer containing deep UV absorbing chromophores in the presence of 0.06% to 4% by weight of dissolved tetramethylammonium hydroxide, the weight percentage being based on the total weight of the corresponding test solution.

[0009] On the surface of the wafer, there are various metals (such as copper, molybdenum, tungsten, cobalt, etc.) with similar removal rates, which, in combination with the multi-component compositions required to achieve suitable removal efficiency, makes the development of suitable PERR compositions challenging. In addition, patterning challenges for direct metal etching of ruthenium and molybdenum at ≤ 32 nm metal pitch are described, for example, in J. Vac. Sci. Technol. B [Journal of Vacuum Science & Technology B] 40, 032802 (2022). It is expected to have MoO sidewalls of about 2 nm on Mo metal lines, which are patterned using a direct metal etching process, and even more in wider lines, which may be the main challenge for integrating Mo in future interconnects. x Sidewalls, which are patterned using a direct metal etching process, and even more in wider lines, which may be the main challenge for integrating Mo in future interconnects.

[0010] Therefore, there is a strong need for cleaning compositions capable of cleaning wafer structures containing molybdenum, which, in addition to removing all other etch residues (especially dry etch residues), also exhibit:

[0011] (a) A low molybdenum static etch rate, which avoids damaging these structures because molybdenum is less expensive than copper;

[0012] (b) Good, preferably complete, removal of molybdenum etch residues (especially etch residues including molybdenum oxide).

[0013] Accordingly, an object of the present invention is to provide a composition for post-etch residue removal (PERR) that allows for good efficiency in removing etch residues, particularly dry etch residues, especially molybdenum etch residues, and most particularly molybdenum oxide residues, as well as good compatibility with substrates, particularly with molybdenum. Another object of the present invention is to provide a composition that shows substantially complete removal of molybdenum etch residues (substantially oxides) while substantially not eroding molybdenum. Summary of the Invention

[0014] One embodiment of the present invention is a composition for removing post-etch residues from a substrate comprising a surface of a molybdenum layer, the composition comprising:

[0015] (a) 10% to 60% by weight of a water-miscible organic solvent;

[0016] (b) 4% to 15% by weight of a C1-C 12 amine;

[0017] (c) 0.1% to 4% by weight of a C4 to C 16 quaternary ammonium hydroxide;

[0018] (d) 0.5% to 5% by weight of a C2 to C 10 polyol;

[0019] (e) 0.01% to 1% by weight of a polyalkoxylated polyethyleneimine;

[0020] (f) 0.001% to 0.07% by weight of at least one guanidine derivative selected from 1,3-diphenylguanidine, 1-(o-tolyl)biguanide, butylbiguanide, phenformin, guanine, chloroguanide hydrochloride, 2-guanidinobenzimidazole, polyhexamethylene biguanide hydrochloride, polyaminopropyl biguanide, chlorhexidine or a chlorhexidine salt; and

[0021] (g) water.

[0022] The composition is also capable of removing substantially all of the etch residues while effectively protecting the molybdenum conductor lines. Additionally, despite the presence of several components, the composition maintains colloidal stability and is further capable of providing suitable PERR performance while preventing any undesired etching or interaction with other metals present on the surface of the wafer.

[0023] Another embodiment of the present invention is the use of the composition as described herein for removing post-etch residues from a semiconductor substrate comprising a surface of a molybdenum layer.

[0024] Yet another embodiment of the present invention is a method for removing post-etch residues from a substrate, the substrate comprising a surface of a molybdenum layer, the composition comprising:

[0025] (a) providing a surface of a microelectronic device, the surface of the microelectronic device comprising the surface of the molybdenum layer and post-etch residues thereon;

[0026] (b) providing a composition as described herein;

[0027] (c) contacting the surface with the composition for a period of time at a temperature effective to remove the post-etch residues without damaging the molybdenum layer. Detailed Description

[0028] A composition for removing post-etch residues from a substrate, the substrate comprising a surface of a molybdenum layer, the composition comprising:

[0029] (a) 10% to 60% by weight of a water-miscible organic solvent;

[0030] (b) 4% to 15% by weight of a C1-C 12 amine;

[0031] (c) 0.1% to 4% by weight of a C4 to C 16 quaternary ammonium hydroxide;

[0032] (d) 0.5% to 5% by weight of a C2 to C 10 polyol;

[0033] (e) 0.01% to 1% by weight of a polyalkoxylated polyethyleneimine;

[0034] (f) 0.001% to 0.07% by weight of at least one guanidine derivative selected from 1,3-diphenylguanidine, 1-(o-tolyl)biguanide, butylbiguanide, phenformin, guanine, chloroguanide hydrochloride, 2-guanidino benzimidazole, polyhexamethylene biguanide hydrochloride, polyaminopropyl biguanide, chlorhexidine or a chlorhexidine salt; and

[0035] (g) water.

[0036] Definitions

[0037] As used herein, "layer" means a portion of a substrate that is disposed separately on the surface of the substrate and has a distinguishable composition relative to an adjacent layer.

[0038] The term "C x " means that the corresponding group contains x number of C atoms. For example, the term "C2 to C 10"Polyol" refers to a hydrocarbon containing from 2 to 10 carbon atoms and bearing 2, 3, 4 or more hydroxyl groups. The hydrocarbon may be selected from straight-chain or branched-chain alkyl groups. Similarly, the term "C1 to C 12 amine" refers to a hydrocarbon containing from 1 to 12 carbon atoms and bearing at least one amine functional group. The hydrocarbon may be selected from straight-chain or branched-chain alkyl groups.

[0039] Unless otherwise indicated, all percentages, ppm or similar values are by weight relative to the total weight of the corresponding composition. The terms "wt%" and "% by weight" are used synonymously herein.

[0040] "Post-etch residue" refers to the material remaining after a gas-phase plasma etching process (e.g., back-end-of-line ("BEOL") dual damascene processing or wet etching process). Post-etch residues can be organic, organometallic, organosilicon, or inorganic in nature, such as silicon-containing materials, carbon-based organic materials, and materials obtained from etching gas residues (such as oxygen and fluorine). When etching a molybdenum layer, molybdenum etch residues may be present, such as molybdenum oxide. Depending on the substrate and the etching method, other non-oxidized compounds of molybdenum may also be present. As is well known to those skilled in the art, the presence of such residues will have a detrimental effect on the final electronic properties of the wafer. The purpose of the PERR composition is to effectively remove the etch residues while minimizing damage to the wafer surface.

[0041] All cited documents are incorporated herein by reference.

[0042] Water-miscible organic solvents

[0043] The cleaning composition comprises one or more water-miscible organic solvents. The water-miscible organic solvents help to dissolve components with low water solubility in the composition and improve the efficiency and solubility of removing organic residues from the wafer surface.

[0044] In the context of the present invention, the term "water-miscible organic solvent" preferably means that an organic solvent meeting this requirement is miscible with water at 20 °C and ambient pressure in a ratio of at least 1:1 (w / w).

[0045] Examples of water-miscible organic solvents that can be employed are:

[0046] (a) Ethers, such as but not limited to tripropylene glycol methyl ether, propylene glycol propyl ether, diethylene glycol n-butyl ether (BDG), dipropylene glycol methyl ether (DPM);

[0047] (b) Sulfur-containing solvents:

[0048] (i) Sulfones, such as but not limited to sulfolane;

[0049] (ii) Sulfoxides, such as but not limited to dimethyl sulfoxide (DMSO);

[0050] (c) An alcohol, such as but not limited to tetrahydrofurfuryl alcohol or a straight-chain or branched C2-C6 alkanol, such as ethanol, n-propanol or isopropanol;

[0051] (d) 4-Methylmorpholine-4-oxide, trimethylamine-N-oxide, triethylamine-N-oxide, triethanolamine-N-oxide, pyridine-N-oxide, N-formylmorpholine, N-ethylmorpholine-N-oxide, N-ethylpyrrolidine-N-oxide; or

[0052] (e) A mixture thereof.

[0053] The water-miscible organic solvent can be protic or aprotic. Preferably, the water-miscible organic solvent is aprotic.

[0054] Preferred solvents are dimethyl sulfoxide, diethyl sulfoxide, methyl ethyl sulfoxide, dipropyl sulfoxide, diphenyl sulfoxide, methyl phenyl sulfoxide, 1,1'-dihydroxybenzene sulfoxide, sulfolane, or a mixture thereof. More preferably, they are dimethyl sulfoxide, diethyl sulfoxide, methyl ethyl sulfoxide, dipropyl sulfoxide, or sulfolane. Most preferably, the solvent is dimethyl sulfoxide, sulfolane, or a mixture thereof.

[0055] Preferably, the amount of the water-miscible organic solvent in the composition can be in the range having a starting point and an ending point selected from the following list of weight percentages: 10, 12, 15, 20, 25, 29, 30, 33, 35, 40, 45, 50, 54, 59.9 and 60. Examples of such ranges of the solvent include about 10% to about 60% by weight of the composition; or about 12% to about 58% by weight; or about 15% to about 55% by weight; or about 16% to about 53% by weight; or about 18% to about 52% by weight; or about 22% to about 50% by weight; or about 20% to about 49.9% by weight, or about 22% to about 45% by weight; or about 25% to about 40% by weight.

[0056] In an individual case, the composition according to the invention as defined herein may further comprise a second water-miscible organic solvent, which is preferably selected from the group consisting of tetrahydrofuran (THF), N-methylpyrrolidone (NMP), dimethylformamide (DMF), dimethyl sulfoxide (DMSO), ethanol, isopropanol, butyl diglycol, butyl glycol, sulfolane (2,3,4,5-tetrahydrothiophene-1,1-dioxide) and mixtures thereof; more preferably selected from the group consisting of THF, NMP, DMF, DMSO, sulfolane and mixtures thereof. In such cases, the first solvent and the second solvent are different.

[0057] Amine

[0058] The cleaning composition contains one or more amines. These amines help remove polymer residues from the wafer substrate.

[0059] In a preferred embodiment, the amine is selected from C1 to C 10 alkylamines and C2 to C 10 alkanolamines. Most preferably, it is C2 to C5 alkanolamines.

[0060] An alkylamine is a compound including an amine group substituted by at least one alkyl group. The alkylamine can be any alkylamine that will function effectively as the cleaning compound as described, including primary, secondary, and tertiary amine compounds. Some useful alkylamines are monoalkylamines such as ethylamine, ethylenediamine, diethylenetriamine, triethylenediamine, tetraethylenepentamine (TEPA), triethylenetetramine, ethylenediamine, hexamethylenediamine, triethylamine, trimethylamine, diethanolamine, and morpholine.

[0061] Preferred alkylamines are those containing one or two primary, secondary, or tertiary amino groups. Even more preferably, such an alkylamine:

[0062] (a) contains one primary amino group;

[0063] (b) contains one secondary or tertiary amino group.

[0064] An alkanolamine is a compound including an amine group substituted by at least one alkanol group. The alkanolamine can be any alkanolamine that will function effectively as the cleaning compound as described, including primary, secondary, and tertiary amine compounds. The alkanolamine compound will have at least one alkanol substituent (such as methanol, ethanol, etc.) and one, two, or three alkanol, alkyl, or alternative organic substituents. Some useful alkanolamines are primary alkanolamines such as monoethanolamine (MEA), aminoethylethanolamine, N-methylethanolamine, aminoethoxyethanol, aminoethoxyethoxyethanol, butoxypropylamine, methoxypropylamine, butoxyisopropylamine, 2-ethylhexylisopropoxyamine, ethanolpropylamine, ethylethanolamine, N-hydroxyethylmorpholine, aminopropyldiethanolamine, dimethylaminoethoxyethanol, diethanolamine, N-methyldiethanolamine, monoethanolamine, triethanolamine, 1-amino-2-propanol, 3-amino-1-propanol, diisopropylamine, aminomethylpropanediol, N,N-dimethylaminomethylpropanediol, aminoethylpropanediol, N,N-dimethylaminoethylpropanediol, isopropylamine, 2-amino-1-butanol, aminomethylpropanol, aminodimethylpropanol, N,N-dimethylaminomethylpropanol, isobutanolamine, diisopropanolamine, 3-amino,4-hydroxyoctane, 2-aminobutanol, tris(hydroxymethyl)aminomethane (TRIS), N,N-dimethyltris(hydroxymethyl)aminomethane, hydroxypropylamine, hydroxyethylamine, tris(hydroxyethyl)aminomethane, and combinations thereof.

[0065] Preferred alkanolamines are those containing one or two hydroxyl groups and one or two primary, secondary or tertiary amino groups. Even more preferred are alkanolamines which:

[0066] (a) contain one or two hydroxyl groups and a secondary or tertiary amino group;

[0067] (b) contain one hydroxyl group and one or two secondary or tertiary amino groups.

[0068] Particularly preferred alkanolamine is 2-(methylamino)ethan-1-ol (or N-methylethanolamine).

[0069] One or more amines may be present in an amount of from about 4% to about 15% by weight, preferably from about 5% to about 14% by weight, more preferably from about 6% to about 11.5% by weight, even more preferably from about 7% to about 13% by weight, and most preferably from about 8% to about 12% by weight.

[0070] Quaternary ammonium hydroxide

[0071] The cleaning composition contains one or more C4 to C 16 Quaternary ammonium hydroxide as a pH regulator to adjust the pH to an alkaline range.

[0072] Quaternary ammonium hydroxide may be present in the composition in an amount of from about 0.5% to about 4% by weight. Preferably, the composition of the present invention contains from 0.7% to 3.5% by weight, more preferably from 1% to 3% by weight, and most preferably from 1.5% to 2.5% by weight of at least one quaternary ammonium hydroxide.

[0073] Preferably, the quaternary ammonium hydroxide may be selected from the group consisting of tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, and (2-hydroxyethyl)triethylammonium hydroxide.

[0074] Preferably, the quaternary ammonium hydroxide may be selected from C4 to C8 alkyl quaternary ammonium hydroxides, particularly selected from tetramethylammonium hydroxide and tetraethylammonium hydroxide.

[0075] Polyol

[0076] The cleaning composition contains one or more C2 to C 10 Polyols. These polyols help to increase surface wetting and dissolve polymer residues from the wafer surface.

[0077] In a preferred embodiment, the C2 to C 10 Polyol is selected from compounds having the formula HOCH2(CHOH) k CH2OH, where k is an integer of 0 or 1 to 8.

[0078] In a preferred embodiment, C2 to C 10 The polyol is selected from ethylene glycol, glycerol, threitol, arabitol, xylitol, ribitol, mannitol, sorbitol, erythritol, pentaerythritol, trimethylolpropane, galactitol, fucitol, iditol, inositol, volemitol, propylene glycol, 1,4-butanediol, diethylene glycol, and combinations thereof, more preferably selected from ethylene glycol, glycerol, erythritol, threitol, arabitol, xylitol, ribitol, mannitol, sorbitol, propylene glycol, 1,4-butanediol, diethylene glycol, and combinations thereof.

[0079] Particularly preferred is a combination of C4 to C8 polyols, preferably a combination of sorbitol and at least one C2 or C3 polyol, most preferably a combination of sorbitol and ethylene glycol.

[0080] The polyol may be present in an amount of about 0.5% to about 5% by weight of C2 to C 10 polyol, preferably about 0.7% to about 4.5% by weight, more preferably about 0.8% to about 4% by weight, even more preferably about 1% to about 3% by weight, and most preferably about 1% to about 2.5% by weight.

[0081] In a preferred embodiment, the polyol comprises or consists essentially of about 0.2% to 1% by weight of C4 to C8 polyol and about 0.5% to 1.5% by weight of C2 or C3 polyol.

[0082] Polyalkoxylated polyethyleneimine

[0083] The composition for removing post-etch residues from a substrate comprises polyalkoxylated polyethyleneimine. When removing post-etch residues from the wafer surface, the combination of polyalkoxylated polyethyleneimine and a guanidine derivative helps to significantly reduce the corrosion of molybdenum, especially molybdenum metal lines.

[0084] The polyalkoxylated polyethyleneimine having a polyethyleneimine backbone is to be understood to mean a compound consisting of a saturated hydrocarbon chain having a terminal amino functional group interrupted by secondary and tertiary amino groups. Such a backbone may be straight-chain or branched. Of course, different polyethyleneimine backbones may be used in mixtures with each other. Depending on the pH of the surrounding environment, some or all of the amino groups on the polyalkoxylated polyethyleneimine may also be reversibly converted to quaternary (cationic) ammonium groups. Alternatively, it is also possible to modify the polymer backbone such that the amino groups are quaternized, and in this case, the polyalkoxylated polyethyleneimine will carry a cationic charge regardless of the environmental pH. Preferably, the polyalkoxylated polyethyleneimine has a cationic charge.

[0085] The main chain contains primary, secondary and tertiary amine nitrogen atoms connected by "linking" units. The main chain essentially contains three types of units, and it should be emphasized that these groups can be distributed along the main chain in any order.

[0086] The units constituting the polyalkyleneimine main chain are (a) primary units having the following formula:

[0087] [H2N-C2H4]- and -NH2

[0088] which terminate the main main chain and any branched chains;

[0089] (b) secondary amine units having the following formula:

[0090]

[0091] and (c) tertiary amine units having the following formula:

[0092]

[0093] which are the branch points of the main main chain and the secondary main chain, A E1 represents the continuation of the chain structure through branching. The continuation of the chain structure through branching herein means that A E1 can contain all of the above primary, secondary and tertiary amine units except for the end group -NH2.

[0094] The polyalkyleneimine of the present invention can be prepared, for example, by polymerizing ethyleneimine in the presence of a catalyst (such as carbon dioxide, sodium bisulfite, sulfuric acid, hydrogen peroxide, hydrochloric acid, acetic acid, etc.). Specific methods for preparing these polyalkyleneimine main chains are disclosed in U.S. Patent 2,182,306, U.S. Patent 3,033,746, U.S. Patent 2,208,095, U.S. Patent 2,806,839 and U.S. Patent 2,553,696.

[0095] In addition, the polyalkyleneimine main chain can be partially substituted with an alkylating agent. The substituents can be selected from C1 to C 12 alkyl, C2 to C 12 alkenyl, C2 to C 12 alkynyl, C6 to C 20 alkylaryl, C6 to C 20 arylalkyl, C6 to C 20 aryl. Preferred substituents can be selected from C1 to C6 alkyl, C6 to C 12 alkylaryl, C6 to C 12 arylalkyl, and C6 to C 12 aryl. Preferably, the aryl is phenyl or naphthyl. The end groups [H2N-X L1 - and -NH2 can also be replaced by the group R L3Substitution.

[0096] Suitable examples of alkylating agents are organic compounds containing an active halogen atom, such as arylalkyl halides, alkyl halides, alkenyl halides, and alkynyl halides. Additionally, compounds such as alkyl sulfates, alkyl sultones, epoxides, etc. can also be used. Non-limiting examples of corresponding alkylating agents include benzyl chloride, propane sultone, dimethyl sulfate, (3-chloro-2-hydroxypropyl)trimethylammonium chloride, etc. Preferably, dimethyl sulfate and / or benzyl chloride are used.

[0097] During the formation of the polyamine backbone, cyclization may occur, and thus, a certain amount of cyclic polyamine may be present in the parent polyalkyleneimine backbone mixture. Each primary and secondary amine unit of the cyclic alkyleneimine undergoes modification by adding polyoxyalkylene units in the same manner as for linear and branched polyalkyleneimines.

[0098] The term "polyalkoxylated polyethyleneimine" means a polyethyleneimine in which the N-hydrogen atoms are replaced by polyoxyalkylene groups containing C2 to C6 oxyalkylene repeating units, preferably C2 to C4 oxyalkylene repeating units, more preferably C2 to C3 oxyalkylene repeating units, and most preferably C2 oxyalkylene repeating units.

[0099] Generally, polyalkyleneimine can be prepared as described above. Then, polyalkoxylation is carried out by reacting the corresponding alkylene oxide with polyethyleneimine. The synthesis of polyoxyalkylene groups is known to those skilled in the art. For example, comprehensive details are given in "Polyoxyalkylenes" in Ullmann’s Encyclopedia of Industrial Chemistry, 6th Edition, Electronic Release. When two or more different alkylene oxides are used, the polyoxyalkylene groups formed can be random copolymers, gradient copolymers, or block copolymers.

[0100] Modification of N-H units in the polymer backbone with oxyalkylene units is carried out, for example, by first reacting a polymer (preferably polyethyleneimine) with one or more alkylene oxides (preferably ethylene oxide, propylene oxide or a mixture thereof) in the presence of up to 80% by weight of water at a temperature of about 25 °C to about 150 °C in an autoclave equipped with a stirrer. In the first step of the reaction, the alkylene oxide is added in such an amount that almost all hydrogen atoms of the N-H units of the polyalkyleneimine are converted to hydroxyalkyl groups to give a monoalkoxylated polyalkyleneimine. Then the water is removed from the autoclave. After adding a basic catalyst, such as sodium methoxide, potassium tert-butoxide, potassium hydroxide, sodium hydroxide, sodium hydride, potassium hydride or a basic ion exchanger, in an amount of 0.1% to 15% by weight relative to the addition product obtained in the first step of alkoxylation, an additional amount of alkylene oxide is added to the reaction product of the first step such that a polyalkoxylated polyalkyleneimine is obtained which contains the expected average number of alkylene oxide units / N-H units of the polymer. The second step can be carried out, for example, at a temperature of about 60 °C to about 150 °C. The second step of alkoxylation can be carried out in an organic solvent (such as xylene or toluene). For the correct metered addition of the alkylene oxide, it is advisable to determine the number of primary and secondary amine groups of the polyalkyleneimine before alkoxylation.

[0101] Alternatively, polyalkoxylation can also be achieved by graft copolymerization of polyethyleneimine.

[0102] The polyalkoxylated polyalkyleneimine can optionally be functionalized with a group different from H in a further reaction step. The type of functionalization depends on the desired end use. Depending on the functionalizing agent, the chain ends can be hydrophobic or more hydrophilic. The additional functionalization can be used to modify the properties of the polyalkoxylated polyalkyleneimine. For example, the hydroxyl groups present in the polyoxyalkylated polyalkyleneimine are converted by a suitable reagent capable of reacting with hydroxyl groups. Esterification of the hydroxyl groups with an acid is a representative reaction.

[0103] Alternatively, carboxyl-functionalized polyalkoxylated polyethyleneimine can be obtained by Michael addition reaction with a suitable α,β-unsaturated substance (such as acrylic acid, methacrylic acid, etc.). Preferably, the polyalkoxylated polyethyleneimine is functionalized with carboxylic acid groups. Michael addition or Michael 1,4 addition is a reaction between a Michael donor (enolate or other nucleophile such as an amine) and a Michael acceptor (usually an α,β-unsaturated carbonyl / carboxyl group) to produce a Michael adduct by forming a carbon-carbon bond at the β-carbon of the acceptor. Such a reaction is also called aza-Michael addition. A further description of it is provided in Additions to and substitutions at C–Cπ-Bonds, M. Mauduit, A. Denicourt-Nowicki, Comprehensive Organic Synthesis (Second Edition), 2014.

[0104] In addition, the polyalkoxylated polyethyleneimine can have a high degree of branching. Preferably, the polyalkoxylated polyethyleneimine is hyperbranched. As used herein, the term "hyperbranched" refers to a highly branched polymer that typically exhibits a globular structure. Hyperbranched polymers typically exhibit significant irregularities in the branching pattern and structure, which typically results in a significant variation in molecular weight (often referred to as polydispersity). A useful measure for evaluating the amount of branching present in a polymer is the degree of branching. As used herein, the term "degree of branching" refers to the ratio of (a) the total number of branched-chain repeating units contained in the polymer to (b) the total number of repeating units contained in the polymer. Hyperbranched polymers with any suitable degree of branching can be used in the compositions described herein. In certain embodiments, the hyperbranched polymer exhibits a degree of branching of at least about 4 to 20 monomer units / molecule. Generally, care should be taken when interpreting the degree of branching information of hyperbranched polymers. For example, some hyperbranched polymers can exhibit a degree of branching of less than about 0.2, but include one or more hyperbranched polymer moieties (or subunits) that exhibit a degree of branching greater than about 0.2. This may be the case, for example, when the hyperbranched polymer core is chain-extended with a long chain of linear repeating units. If sufficiently chain-extended, the overall degree of branching of such polymers can be less than about 0.2.

[0105] The weight-average molecular weight M of the polyalkoxylated polyalkyleneimine w can be from about 500 g / mol to about 500,000 g / mol. The lower limit of the weight-average molecular weight M of the polyalkoxylated polyalkyleneimine w is generally about 1500 g / mol, preferably about 2500 g / mol, more preferably about 5000 g / mol. The weight-average molecular weight Mw The upper limit is usually about 500,000 g / mol, preferably about 150,000 g / mol, more preferably about 50,000 g / mol, and most preferably about 25,000 g / mol. A particularly preferred range is from 800 to 25,000 g / mol, and most particularly from 5,000 to 25,000 g / mol. The molecular weight can be determined by size exclusion chromatography (such as GPC) using polymethyl methacrylate (PMMA) as a standard and hexafluoroisopropanol + 0.05% potassium trifluoroacetate as an eluent.

[0106] The polyalkoxylated polyalkyleneimine can be present in an amount of about 0.01% to about 1% by weight, preferably about 0.015% to about 0.8% by weight, more preferably about 0.02% to about 0.7% by weight, even more preferably about 0.04% to about 0.5% by weight, and most preferably about 0.05% to about 0.3% by weight. It has been found that an amount of polyalkoxylated polyalkyleneimine below 0.01 wt.% is not sufficient to protect molybdenum on the wafer surface. On the other hand, a further increase in concentration above 1 wt.% is possible, but it does not significantly improve the corrosion inhibition performance of the polyethyleneimine. Additionally, since many components are involved in obtaining the composition, a fine balance is typically required to ensure colloidal stability. Here, the presence of a high amount (above 1 wt.%) of (polymeric) components such as polyalkoxylated polyethyleneimine can be detrimental to the long-term stability of the multi-component system, especially in a substantially aqueous medium. The presence of 0.01% to 1% by weight of polyalkoxylated polyethyleneimine in the composition results in good PERR characteristics while ensuring good colloidal stability, even under long-term testing.

[0107] Guanidine derivatives

[0108] The composition of the present invention currently claimed for protection comprises at least one guanidine derivative in an amount of 0.001% to 0.07% by weight, which is selected from 1,3-diphenylguanidine, 1-(o-tolyl)biguanide, butabiguanide, phenformin, guanine, chloroguanide hydrochloride, 2-guanidinobenzimidazole, polyhexamethylene biguanide hydrochloride, polyaminopropyl biguanide, chlorhexidine or chlorhexidine salts.

[0109] When removing the post-etch residues from the wafer surface, at least one guanidine derivative significantly reduces the corrosion of molybdenum, especially molybdenum metal lines. It has been found that compared with the composition without guanidine derivatives, the addition of guanidine derivatives results in a lower etch rate on blanket PVDMo, but still allows good, preferably complete, removal of the etch residues.

[0110] More preferably, the guanidine derivative is selected from chlorhexidine or a chlorhexidine salt. It is known that chlorhexidine or its salts degrade into chemical subclasses (or degradation products) over an extended period of time. However, it has been noted that this degradation has little or no effect on the PERR activity outlined herein. The concentration of the product can vary with conditions (temperature / pressure, etc.). Some possible degradation products are reproduced below as listed in Table II-1 on page 19 of the paper by Zhixin Zong titled Studies on the mechanisms of solid state and solution instability of drugs. For a person skilled in the art, manipulating the degradation products and / or their concentration to enhance the activity is considered routine.

[0111]

[0112] Preferably, the chlorhexidine or chlorhexidine salt includes the degradation products listed above.

[0113] Preferably, the guanidine derivative is chlorhexidine.

[0114] Preferably, the guanidine derivative is selected from chlorhexidine salts.

[0115] More preferably, the chlorhexidine salt is selected from the group consisting of chlorhexidine gluconate, chlorhexidine digluconate, chlorhexidine hydrochloride, chlorhexidine dihydrochloride, chlorhexidine acetate, chlorhexidine diacetate, chlorhexidine hexametaphosphate, chlorhexidine metaphosphate, and chlorhexidine trimetaphosphate.

[0116] Most preferably, the guanidine derivative is selected from the group consisting of chlorhexidine, chlorhexidine gluconate, and chlorhexidine digluconate.

[0117] Most preferably, the composition comprises at least one guanidine derivative selected from the group consisting of 1,3-diphenylguanidine, 1-(o-tolyl)biguanide, chlorhexidine, or a chlorhexidine salt.

[0118] Thus, this ensures the possibility that the composition includes a higher water content (preferably at least 40 wt.%, more preferably at least 45 wt.%, even more preferably at least 50 wt.%, most preferably at least 51 wt.%). Such substantially aqueous compositions not only have economic benefits but also have a positive environmental impact.

[0119] At least one guanidine derivative is present in an amount of from about 0.001% to about 0.07% by weight, preferably from about 0.005% to about 0.065% by weight, more preferably from about 0.008% to about 0.06% by weight.

[0120] Water

[0121] The etching composition of the present invention is water-based and thus contains water. Water has several functions, such as dissolving one or more components in the composition, serving as a carrier for the components, serving as an aid for removing residues, serving as a viscosity regulator for the composition, and serving as a diluent. Preferably, the water used in the composition is deionized (DI) water. The ranges of water described in the next paragraph include all water from any source in the composition.

[0122] For most applications, the weight percentage of water in the composition will be present in a range having a starting point and an ending point selected from the following group of numbers: 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 92, 94, 96. Examples of ranges of water that can be used in the composition include, for example, from about 20% to about 80% by weight, or from about 25% to about 75% by weight, or from about 30% to about 72% by weight, or from about 35% to about 70% by weight, or from about 40% to about 65% by weight, or from about 45% to about 55% by weight of water. Still other preferred embodiments of the present invention may include water in an amount to achieve the desired weight percentages of the other components.

[0123] Preferably, the composition is substantially water-based.

[0124] Preferably, the composition contains at least 40 wt.%, more preferably 45 wt.%, even more preferably at least 50 wt%, and most preferably at least 51 wt.% of water.

[0125] Chelating agent

[0126] The cleaning composition may optionally contain one or more chelating agents.

[0127] Preferred chelating agents are 1,2-cyclohexylenedinitrilotetraacetic acid, 1,1,1,5,5,5-hexafluoro-2,4-pentanedione, acetylacetonate, 2,2'-azanediyl diacetic acid, ethylenediaminetetraacetic acid, etidronic acid, methanesulfonic acid, acetylacetone, 1,1,1-trifluoro-2,4-pentanedione, 1,4-benzoquinone, 8-hydroxyquinoline, salicylideneaniline; tetrachloro-1,4-benzoquinone, 2-(2-hydroxyphenyl)-benzoxazole, 2-(2-hydroxyphenyl)-benzothiazole, hydroxyquinoline sulfonic acid, sulfosalicylic acid, salicylic acid, pyridine, 2-ethylpyridine, 2-methoxypyridine, 3-methoxypyridine, 2-methylpyridine, dimethylpyridine, piperidine, piperazine, ethylamine, methylamine, isobutylamine, tert-butylamine, tributylamine, dipropylamine, dimethylamine, diethanolamine, methyldiethanolamine, pyrrole, isoxazole, bipyridine, pyrimidine, pyrazine, pyridazine, quinoline, isoquinoline, indole, 1-methylimidazole, diisopropylamine, diisobutylamine, aniline, pentamethyldiethylenetriamine, acetoacetamide, ammonium carbamate, ammonium pyrrolidinedithiocarbamate, dimethyl malonate, methyl acetoacetate, N-methylacetoacetamide, tetramethylammonium thiobenzoate, 2,2,6,6-tetramethyl-3,5-heptanedione, tetramethylthiuram disulfide, lactic acid, ammonium lactate, formic acid, propionic acid, γ-butyrolactone, and mixtures thereof.

[0128] The chelating agent can be 1,2-cyclohexylenedinitrilotetraacetic acid (CDTA) or can contain CDTA and one or more of the other chelating agents described above.

[0129] Also preferred are compositions according to the invention as defined herein, wherein the amount of one or more chelating agents present, based on the total weight of the composition, is from about 0.01% to about 4% by weight, preferably from about 0.02% to about 1% by weight, more preferably from about 0.05% to about 0.8% by weight.

[0130] Surfactant

[0131] The composition can further comprise one or more surfactants.

[0132] Preferred surfactants are selected from the group consisting of:

[0133] (i) Anionic surfactants, which are preferably selected from the group consisting of ammonium lauryl sulfate, fluorosurfactants, preferably selected from the group consisting of perfluorinated alkylsulfonamide salts (preferably perfluorinated, N-substituted alkylsulfonamide ammonium salts, PNAAS), perfluorooctanesulfonates, perfluorobutanesulfonates, perfluorononanoates, and perfluorooctanoates; alkyl-aryl ether phosphates and alkyl ether phosphates;

[0134] (ii) Zwitterionic surfactants, which are preferably selected from the group consisting of: (3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate) (“CHAPS”), coconut amide propyl hydroxysulfobetaine (CAS RN 68139-30-0), {[3-(dodecanoylamino)propyl](dimethyl)-ammonio}acetate, phosphatidylserine, phosphatidylethanolamine, phosphatidylcholine; and

[0135] (iii) Nonionic surfactants, which are preferably selected from the group consisting of: glucoside alkyl ethers, glycerol alkyl ethers, coconut amide ethanolamine, and lauryldimethylamine oxide.

[0136] More preferred surfactants in the compositions according to the invention are or comprise perfluorinated, N-substituted alkylsulfonamide ammonium salts. The preferred surfactant (E) in the compositions according to the invention does not contain metals or metal ions.

[0137] Also preferred are the compositions according to the invention as defined herein, wherein, based on the total weight of the composition, the amount of one or more surfactants present in the surfactants is in an amount of from about 0.0001% to about 1% by weight, preferably from about 0.0005% to about 0.5% by weight, more preferably from about 0.001% to about 0.01% by weight.

[0138] Specific surfactants for use in the compositions described herein include, but are not limited to, bis(2-ethylhexyl) phosphate, perfluoroheptanoic acid, perfluorodecanoic acid, trifluoromethanesulfonic acid, phosphonoacetic acid, dodecenylsuccinic acid, dioctadecyl hydrogen phosphate, octadecyl dihydrogen phosphate, dodecylamine, dodecenylsuccinic acid mono-diethanolamide, lauric acid, palmitic acid, oleic acid, juniperic acid, 12-hydroxystearic acid, and dodecyl phosphate; polyoxyethylene lauryl ether (Emalmin NL-100 (Sanyo), Brij 30, Brij 98, Brij35), dodecenylsuccinic acid mono-diethanolamide (DSDA, Sanyo), ethylenediamine tetra(ethoxylate-block-propoxylate) tetraol (Tetronic 90R4), polyethylene glycol (e.g., PEG400), polypropylene glycol, polyethylene glycol ether or polypropylene glycol ether, block copolymers based on ethylene oxide and propylene oxide (Newpole PE-68 (Sanyo), Pluronic L31, Pluronic 31R1, Pluronic L61, Pluronic F-127) (Dynol 607), polyoxypropylene sucrose ether (SN008S, Sanyo), tert-octylphenoxy polyethoxyethanol (Triton X100), 10-ethoxy-9,9-dimethyldecan-1-amine ( CF-32), branched polyoxyethylene (9) nonylphenyl ether (IGEPAL CO-250), branched polyoxyethylene (40) nonylphenyl ether (IGEPAL CO-890), polyoxyethylene sorbitol hexaoleate, polyoxyethylene sorbitol tetraoleate, polyethylene glycol sorbitan monooleate (Tween80), sorbitan monooleate (Span 80), a combination of Tween 80 and Span 80, alcohol alkoxylates (e.g., Plurafac RA-20), alkyl-polyglucosides, ethyl perfluorobutyrate, 1,1,3,3,5,5-hexamethyl-1,5-bis[2-(5-norbornene-2-yl)ethyl]trisiloxane, monomeric octadecylsilane derivatives such as SIS6952.0 (Siliclad, Gelest), siloxane-modified polysilazanes such as PP1-SG10 Siliclad Glide 10 (Gelest), silicone-polyether copolymers such as Silwet L-77 (Setre Chemical), Silwet ECO spreader (Momentive), and ethoxylated fluorosurfactants( FSO-100, FSN-100); cetyltrimethylammonium bromide (CTAB), heptadecafluorooctanesulfonic acid, tetraethylammonium, stearyltrimethylammonium chloride (Econol TMS-28, Sanyo), 4-(4-diethylaminophenylazo)-1-(4-nitrobenzyl)pyridinium bromide, cetylpyridinium chloride monohydrate, benzyldimethyldodecylammonium chloride, benzyldimethylhexadecylammonium chloride, hexadecyltrimethylammonium bromide, dimethyldioctadecylammonium chloride, dodecyltrimethylammonium chloride, hexadecyltrimethylammonium p-toluenesulfonate, didodecyldimethylammonium bromide, di(hydrogenated tallow)dimethylammonium chloride, tetraheptylammonium bromide, tetra(decyl)ammonium bromide, 336 and oxyphenonium bromide, guanidine hydrochloride (C(NH2)3Cl) or trifluoromethanesulfonates such as tetrabutylammonium trifluoromethanesulfonate, dimethyldioctadecylammonium chloride, dimethyldihexadecylammonium bromide, and di(hydrogenated tallow)dimethylammonium chloride (e.g., Arquad 2HT-75, Akzo Nobel), bromide-containing surfactants such as 1-hexadecyltrimethylammonium bromide.

[0139] In some embodiments, the compositions of the invention will be free or substantially free of any or all of the optional surfactants listed above.

[0140] Other commonly known optional components (such as dyes, pH regulators, stabilizers, buffers, dispersants, chemical modifiers, biocides, etc.) can be included in the cleaning composition in conventional amounts to such an extent that they do not adversely affect the performance of the composition, for example, in amounts up to a total of about 1% or 5% or 10% by weight of the composition. The presence of one or more of the above optional ingredients can be beneficial to the composition. For example, the presence of a dispersant can positively affect the colloidal stability of the composition.

[0141] Alternatively, the cleaning composition can be free or substantially free of any or all of the above optional components.

[0142] Composition

[0143] Methods for preparing a composition for removing post-etch residues from a substrate are generally known. These methods can be used to prepare the compositions of the invention claimed herein. The cleaning composition is typically prepared by mixing the components together in a container at room temperature until all solids have dissolved in the aqueous medium. This can be carried out by dispersing or dissolving the components (b), (c), (d), (e), and (f) described above in a solution of the water-miscible organic solvent (a) and water (g). Optional ingredients (such as pH regulators or surfactants) can be added simultaneously with the other ingredients (b)-(f). For this purpose, conventional and standard mixing methods and mixing equipment can be used, such as stirred vessels, high-shear impellers, ultrasonic mixers, homogenizer nozzles, or countercurrent mixers.

[0144] The dissolution of components (b) to (f) in a solution of the water-miscible organic solvent (a) and water (g) is a key criterion, and for this, the addition of one or more components is not restricted by any particular order. However, to ensure long-term storage stability, one or more of the components (a) to (g) can be added partially or completely just before use. For example, all the components of the composition can be combined together at the manufacturer, before use, and / or during use.

[0145] Generally, the pH of the composition can be in the range of 8 to 14. In a preferred embodiment, the pH of the etching composition is from about 9 to about 13, more preferably from about 10 to about 13, and most preferably from about 11 to about 12.5.

[0146] A cleaning composition is particularly preferred, wherein the composition comprises or consists essentially of the following:

[0147] (a) 10% to 60% by weight of a water-miscible aprotic organic solvent, particularly a sulfoxide or a sulfone, most particularly dimethyl sulfoxide or sulfolane;

[0148] (b) 4% to 15% by weight of C1-C 12amines, especially alkanolamines, most especially 2-(methylamino)ethan-1-ol;

[0149] (c) 0.1% to 4% by weight of C4 to C 16 quaternary ammonium hydroxides, especially C4 to C8 quaternary ammonium hydroxides, most especially tetramethylammonium hydroxide or tetraethylammonium hydroxide;

[0150] (d) 0.5% to 5% by weight of C2 to C 10 polyols, especially compounds of the formula HOCH2(CHOH) k CH2OH where k is an integer from 0 or 1 to 8, most especially sorbitol, ethylene glycol or mixtures thereof;

[0151] (e) 0.01% to 1% by weight of polyalkoxylated polyethyleneimine, especially polyalkoxylated polyethyleneimine functionalized with carboxylic acid groups, most especially polyalkoxylated polyethyleneimine functionalized with carboxylic acid groups and having a weight average molecular weight of 500 to 500 000 g / mol;

[0152] (f) 0.001% to 0.07% by weight of at least one guanidine derivative selected from 1,3-diphenylguanidine, 1-(o-tolyl)biguanide, butabiguanide, phenformin, guanine, chloroguanide hydrochloride, 2-guanidinobenzimidazole, polyhexamethyleneguanidine hydrochloride, polyaminopropylbiguanide, chlorhexidine or chlorhexidine salts; and

[0153] (g) water;

[0154] Another cleaning composition is particularly preferred, wherein the composition comprises the following or consists essentially of the following:

[0155] (a) 20% to 50% by weight of a water-miscible aprotic organic solvent;

[0156] (b) 7% to 13% by weight of an amine;

[0157] (c) 0.5% to 3% by weight of a quaternary ammonium hydroxide;

[0158] (d) 1% to 3% by weight of C2 to C 10 polyol;

[0159] (e) 0.02% to 0.5% by weight of polyalkoxylated polyethyleneimine;

[0160] (f) at least one guanidine derivative in an amount of 0.005% to 0.065% by weight, the guanidine derivative being selected from 1,3-diphenylguanidine, 1-(o-tolyl)biguanide, butabiguanide, phenformin, guanine, chloroguanide hydrochloride, 2-guanidino benzimidazole, polyhexamethylene biguanide hydrochloride, polyaminopropyl biguanide, chlorhexidine or a chlorhexidine salt; and

[0161] (g) water.

[0162] In this context, "essentially" means that the content of any other compound except the specifically mentioned compound is less than 1% by weight, preferably less than 0.1% by weight, even more preferably less than 0.01% by weight, and most preferably below the detection limit.

[0163] Compositions according to the invention as defined herein are particularly preferred, wherein the composition consists of the compounds as defined herein and to be defined based on the examples.

[0164] Application

[0165] On the other hand, a method for removing post-etch residues from a substrate is provided, the substrate comprising a surface of a molybdenum layer, the method comprising:

[0166] (a) providing a surface of a microelectronic device, the surface of the microelectronic device comprising the surface of the molybdenum layer and post-etch residues thereon;

[0167] (b) providing a composition as described herein;

[0168] (c) contacting the surface with the composition for a period of time at a temperature effective to remove the post-etch residues without damaging the molybdenum layer.

[0169] Without limitation, such layers can be present in the wires of a damascene structure.

[0170] It should be understood that it is common practice to prepare a concentrated form of the composition to be diluted before use. For example, the composition can be manufactured in a more concentrated form and thereafter diluted with water and / or other water-miscible solvents at the manufacturer, before use and / or during use.

[0171] When using the composition described herein, the composition is typically contacted with the device structure for a sufficient time at a temperature effective to remove the post-etch residues without damaging the molybdenum layer. Preferably, at a temperature preferably in the range of about 30 °C to about 90 °C, more preferably about 35 °C to about 60 °C, the contact time is about 1 minute to about 200 minutes, more preferably about 1 minute to about 10 minutes. Such contact times and temperatures are illustrative, and any other suitable time and temperature conditions effective to achieve the required removal selectivity can be employed.

[0172] After achieving the desired etch behavior, the composition can be readily removed from the microelectronic device on which it has been previously applied, e.g., by rinsing, washing, or one or more other removal steps that may be desirable and effective in a given end-use application of the composition of the present invention. For example, the device can be rinsed with a rinse solution comprising deionized water, an organic solvent, and / or dried (e.g., spin-dried, N2, vapor dried, etc.).

[0173] Preferably, for measurements carried out at 40 °C, the Mo etch rate of the composition is ≤13.2 Å / min, more preferably ≤10.0 Å / min, and even more preferably ≤8.0 Å / min.

[0174] The contacting step is followed by an optional rinsing step. The rinsing step can be carried out by any suitable means, e.g., rinsing the substrate with deionized water by dipping or spraying techniques. In a preferred embodiment, the rinsing step can be carried out using a mixture of deionized water and an organic solvent such as isopropyl alcohol. The organic solvent can be the same as or different from the water-miscible organic solvent (a).

[0175] The contacting step and the optional rinsing step are followed by an optional drying step, which is carried out by any suitable means, e.g., isopropyl alcohol (IPA) vapor drying, heating, or by centripetal force.

[0176] The compositions described herein can be advantageously used in a method for manufacturing a semiconductor device, the method comprising the step of selectively removing post-etch residues from the surface of a microelectronic device comprising a molybdenum layer as described herein.

[0177] The following examples are intended to further illustrate the invention without limiting the scope of the invention.

[0178] Examples

[0179] Etching experiments were carried out as follows on a full-wafer sample comprising a PVD Mo layer having a thickness of 47.5 nm.

[0180] 100 ml of the etchant solution was placed in a 150 ml beaker, and the beaker was placed in a temperature-controlled water bath. Then, a 2.5 cm × 2.5 cm sample of the corresponding substrate was immersed in the test solution at the desired temperature while stirring the solution at a speed of 250 rpm. The etching of both full-wafer samples was carried out for 2 min, followed by rinsing with deionized water (DIW) for 30 s, and then drying the sample with an N2 gun. The full-wafer sample etching experiments were carried out at 40 °C and 60 °C.

[0181] The thickness of the full-wafer sample was determined by XRF measurement.

[0182] The etch rate was calculated according to the following formula:

[0183]

[0184] Example 1

[0185] Prepare 100 g of the composition by adding the following components in the specified order:

[0186] 1. 52.99 g of DIW

[0187] 2. 2.34 g of DMSO (from BASF)

[0188] 3. 10.3 g of 2-(methylamino)ethan-1-ol (from ACROS)

[0189] 4. 1 g of ethylene glycol (from BASF)

[0190] 5. 4 g of a 25 wt.% TMAH solution in DIW (from BASF)

[0191] 6. 0.6 g of sorbitol (from BASF)

[0192] 7. 0.1 g of an acrylic-functionalized polyethoxylated polyethyleneimine copolymer with an average of 10 EO / N-H groups (M w = 25 000 g / mol) (from BASF)

[0193] 8. 0.01 g of chlorhexidine digluconate (from Sigma-Aldrich)

[0194] The solution was stirred with a magnetic stir bar at a speed of 100 rpm during mixing.

[0195] Prepare compositions with different components and concentrations in the same order as above (see Table 1 below), and adjust the amount of DIW to make the total weight up to 100.

[0196] Determine the Mo etch rate (ER) of the solution at 40 °C and 60 °C on blank samples. The compositions and results are shown in Table 1.

[0197] Table 1

[0198]

[0199] Table 2

[0200]

[0201] All examples IE to IE6 (Table 2) were found to be colloidally stable (soluble) and also provided improved Mo corrosion inhibition, as evidenced by the low Mo etch rate. On the other hand, comparative example C1, which does not contain at least a guanidine derivative (for comparative examples, see Table 1), produced a higher Mo etch rate than any formulation (examples IE1 to IE6) containing at least one guanidine derivative at different concentrations. Both the concentration and the selection of the components are crucial for ensuring not only suitable performance but also suitable colloidal stability. Comparative examples C6 and C7, containing 0.1 wt.% and 0.5 wt.% chlorhexidine digluconate, respectively, produced turbid or cloudy solutions, thus indicating colloidal instability at concentrations above the critical concentration range (0.01 to 0.07 wt.% relative to the total weight of the composition). In addition, the mere presence of at least one guanidine derivative (at a suitable concentration) does not provide suitable Mo inhibition, and the combination of the components listed in Table 1 is key. For example, it was found that the absence of polyalkoxylated polyethyleneimine in comparative example C4 led to poor Mo inhibition. Furthermore, the random selection of guanidine group-containing compounds does not result in suitable Mo inhibition (see comparative examples C2, C3, and C5 in Table 2), thus indicating the need for careful selection of at least one guanidine derivative at a concentration of 0.001% to 0.07% by weight, selected from 1,3-diphenylguanidine, 1-(o-tolyl)biguanide, but biguanide, phenformin, guanine, chloroguanide hydrochloride, 2-guanidino benzimidazole, polyhexamethylene biguanide hydrochloride, polyaminopropyl biguanide, chlorhexidine or chlorhexidine salts. In addition, the composition was found to be beneficial for removing post-etch residues on the Mo half-embedded structure.

Claims

1. A composition for removing post-etch residues from a substrate, the substrate comprising a surface of a molybdenum layer, the composition comprising: (a) 10% to 60% by weight of a water-miscible organic solvent; (b) 4% to 15% by weight of C1-C 12 amine; (c) 0.1% to 4% by weight of C4 to C 16 quaternary ammonium hydroxide; (d) 0.5% to 5% by weight of C2 to C 10 polyol; (e) 0.01% to 1% by weight of a polyalkoxylated polyethyleneimine; (f) 0.001% to 0.07% by weight of at least one guanidine derivative selected from 1,3-diphenylguanidine, 1-(o-tolyl)biguanide, butabiguanide, phenformin, guanine, chloroguanide hydrochloride, 2-guanidino benzimidazole, polyhexamethylene biguanide hydrochloride, polyaminopropyl biguanide, chlorhexidine or a chlorhexidine salt; and (g) water.

2. The composition according to claim 1, wherein The organic solvent is a sulfur-containing aprotic organic solvent, especially from sulfoxides or sulfones.

3. The composition according to any one of the preceding claims, wherein, The organic solvent is selected from dimethyl sulfoxide, diethyl sulfoxide, methyl ethyl sulfoxide, dipropyl sulfoxide or sulfolane.

4. The composition according to any one of the preceding claims, wherein, The amine is selected from C1 to C 10 alkylamines or C2 to C 10 alkanolamines.

5. The composition according to any one of the preceding claims, wherein, The amine is 2-(methylamino)ethan-1-ol.

6. The composition according to any one of the preceding claims, wherein, The quaternary ammonium hydroxide is selected from C4 to C8 alkyl quaternary ammonium hydroxides, preferably selected from tetramethylammonium hydroxide or tetraethylammonium hydroxide.

7. The composition according to any one of the preceding claims, wherein, The C2 to C 10 The polyol is selected from compounds having the formula HOCH2(CHOH) k CH2OH, where k is an integer from 0 or 1 to 8.

8. The composition according to any one of the preceding claims, wherein, The C2 to C 10 The polyol is selected from ethylene glycol, glycerol, erythritol, threitol, arabitol, xylitol, ribitol, mannitol, sorbitol, galactitol, fucitol, iditol, inositol, heptitol, propylene glycol, 1,4-butanediol, diethylene glycol, or a combination thereof.

9. The composition according to any one of the preceding claims, wherein The polyalkoxylated polyethyleneimine has a weight-average molecular weight Mw of 500 to 500,000 g / mol, preferably 5,000 to 25,000 g / mol.

10. The composition according to any one of the preceding claims, wherein, The polyalkoxylated polyethyleneimine has ethylene oxide repeating units in the range of 2 to 25, preferably 5 to 15 repeating units.

11. The composition according to any one of the preceding claims, wherein, The polyalkoxylated polyethyleneimine is functionalized with carboxylic acid groups.

12. The composition according to any one of the preceding claims, having a pH of 10 to 13, preferably 11 to 12.

5.

13. The composition according to any one of the preceding claims, consisting essentially of: (a) 20% to 50% by weight of a water-miscible organic solvent; (b) 7% to 13% by weight of an amine; (c) 0.5% to 3% by weight of a quaternary ammonium hydroxide; (d) 1% to 3% by weight of C2 to C 10 polyol; (e) 0.02% to 3% by weight of a polyalkoxylated polyethyleneimine; (f) 0.005% to 0.065% by weight of at least one guanidine derivative selected from 1,3-diphenylguanidine, 1-(o-tolyl)biguanide, butabiguanide, phenformin, guanine, chloroguanide hydrochloride, 2-guanidino benzimidazole, polyhexamethylene biguanide hydrochloride, polyaminopropyl biguanide, chlorhexidine or a chlorhexidine salt; and (g) water.

14. Use of the composition according to any one of the preceding claims for removing post-etch residues from a semiconductor substrate comprising molybdenum.

15. A method for removing post-etch residues from a substrate, the substrate comprising a surface of a molybdenum layer, the composition comprising: (a) Providing a surface of a microelectronic device, the surface of the microelectronic device comprising the surface of the molybdenum layer and post-etch residues thereon; (b) Providing the composition according to any one of claims 1 to 13; (c) Contacting the surface with the composition for a period of time at a temperature effective to remove the post-etch residues without damaging the molybdenum layer.

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