Solution for post etch residue removal (PERR)

Abstract

The present invention relates to a concentrate for preparing a composition for removing post etch residues from a substrate, the substrate comprising a surface of a ruthenium layer (2) and of a TiN layer (3), the concentrate comprising: (a) 0.5 to 4 % by weight of an imidazole compound; (b) 0.2 to 2 % by weight of a TiN etching activator selected from a phosphonic acid, phosphoric acid, or salts thereof; (c) 0.02 to 1 % by weight of a polyethyleneimine; (d) 0 to 5% by weight of a pH adjusting agent capable of adjusting the pH to 7 to 10; and (f) water; wherein the pH of the concentrate is of from 7 to 10, preferably 8 to 9.5.

Description

[0001] Solution for post etch residue removal (PERR)

[0002] The present invention relates to a composition, its use and a process for post etch residue removal (PERR) of substrates, particularly semiconductor substrates, comprising ruthenium and TIN.

[0003] Background of the Invention

[0004] Resists such as deep UV photo resists or electron beam resists are used in the microlithographic technique for producing a wide range of electrical devices, e.g. semiconductor integrated circuits (ICs), liquid crystal panels, organic electroluminescent panels, printed circuit boards, micro machines, DNA chips and micro plants, in particular ICs with LSI (large-scale integration) or VLSI (very-large-scale integration).

[0005] Copper is customarily used as the low electrical resistance or wiring material in the electrical devices, in particular in the vias and interconnects contained in the ICs. The increasing use of copper and the ever decreasing dimensions of the electrical structures together with the ever increasing functionalities of the ICs require the use of low-k and ultra low-k materials in order to avoid problems with wiring resistance and wiring delay caused by high wiring capacities. These challenging developments have demanded and still demand the continuing optimization of the methods of manufacture and of the materials utilized therefore.

[0006] Although damascene patterning had to overcome many technical challenges, copper-based interconnects have been around for many consecutive technology nodes. As we are progressing toward local BEOL interconnect metal pitches of 20 nm and smaller (for technology nodes beyond N2), the resistance of Cu metal lines increases very fast at such small dimensions due to electron scattering at surfaces and at grain boundaries. Moreover, Cu metal lines require a liner to prevent Cu diffusion in the dielectric material. As this liner needs a fixed thickness to prevent diffusion, scaling Cu interconnects without being able to scale the liner thickness results in a significant relative increase in metal resistance as a function of reducing critical dimension.

[0007] Ru is a highly promising alternative to Cu as a back-end-of-line (BEOL) interconnect metal for future technology nodes, due to its lower thickness dependence of resistivity compared to Cu. Additionally, Ru offers other advantages over Cu, such as its higher resistance to oxidation and electron migration, longer lifetime, and superior mechanical strength.

[0008] Moreover, Ru can be patterned using direct metal etch (DME), which reduces processing costs by eliminating the need for costly steps in a typical damascene patterning scheme. DME also enables the control of the aspect ratio of patterned lines by adjusting the thickness of the deposited metal and the etch process. This provides the opportunity to explore novel integration schemes that are challenging to achieve with traditional dual-damascene approaches. Recent study, J. Vac. Sci. Technol. B 40(3) May / Jun 2022, showed that Ru lines with critical dimensions of 9-10 nm targeting metal pitches of 18 metal pitch (MP) to 26 MP, can be successfully patterned using DME. This integration scheme is commonly referred to as semi-damascene integration.

[0009] To pattern Ru using DME, it is necessary to have a TIN adhesion layer beneath Ru. This is because Ru has poor adhesion on standard dielectric materials. Additionally, TIN serves as a conductive etch stop layer (ESL). As a result of Ru DME patterning, residues containing Ti and Ru are formed in 18 MP semi-damascene structures, as illustrated in Figure 1. Etching of these TIN layers may result in deformation of the whole structures.

[0010] Therefore, there is a strong need for etching compositions that are capable of etching wafer structures comprising ruthenium and TIN which show, besides the removal of all other etch residues, particularly dry etch residues

[0011] (a) a very low ruthenium static etch rate that avoids damaging the structures;

[0012] (b) a low TIN static etch rate; and

[0013] (b) a good, preferably complete, removal of ruthenium and titanium etch residues, particularly etch residues that include ruthenium and / or titanium oxides or oxynitrides.

[0014] It is therefore an object of the invention to provide a composition for post etch residue removal that allows good PERR efficiency, removal of the etch residues, particularly the ruthenium etch residues, most particularly the ruthenium oxide residues, and good compatibility with the substrate, particularly with ruthenium and TIN. It is a further object of the invention to provide a composition that shows essentially complete removal of ruthenium etch residues (essentially oxides) while essentially not attacking the TIN.

[0015] Summary of the Invention

[0016] A first embodiment of the present invention is a concentrate for preparing a composition for removing post etch residues from a substrate, the substrate comprising a surface of a ruthenium layer and of a TIN layer, the concentrate comprising:

[0017] (a) 0.5 to 4 % by weight of an imidazole compound;

[0018] (b) 0.2 to 2 % by weight of a TIN etching activator selected from a phosphonic acid, phosphoric acid, or salts thereof;

[0019] (c) 0.02 to 1 % by weight of a polyethyleneimine;

[0020] (d) 0 to 5% by weight of a pH adjusting agent capable of adjusting the pH to 7 to 10; and

[0021] (f) water; wherein the pH of the concentrate is of from 7 to 10, preferably 8 to 9.5.

[0022] Another embodiment is an etching composition for removing post etch residues from a substrate, the substrate comprising a surface of a ruthenium layer and of a TIN layer, the composition comprising:

[0023] (A) the concentrate according to anyone of the preceding claims;

[0024] (B) an oxidizing agent, particularly hydrogen peroxide; in a mixing ratio A / B of from 10: 1 to 1 : 1 by weight.

[0025] The composition is capable of removing essentially all etch residues while effectively protecting the ruthenium conductor lines and the TIN layers. Etching of these TIN layers that result in deformation of the whole structures is avoided. Another embodiment of the present invention is the use of a composition as described herein for removing post etch residues from a semiconductor substrate comprising a surface of a ruthenium layer and a TIN layer.

[0026] Yet another embodiment of the present invention is a process of removing post etch residues from a substrate, the substrate comprising a surface of a ruthenium layer and of a TIN layer, the process comprising:

[0027] (a) providing a microelectronic device surface that includes the surface of the ruthenium layer, the TIN layer, and post etch residues thereon;

[0028] (b) providing an etching composition according to anyone of claim 10 to 13;

[0029] (c) contacting the surface with the composition for a time and at a temperature effective to remove the post etch residues while not compromizing the ruthenium layer and the TIN layer.

[0030] Brief description of the Figures

[0031] Fig. 1 shows a scheme of a typical semi-damascene film stack useful to be treated by a composition according to the subject invention that comprises an SiC>2 wafer 1, a ruthenium (Ru) layer 2, TIN layers 3 below and above the Ru layer 2, and a layer 4 comprising an SIN hard mask and SiOx.

[0032] Detailed Description of the Invention

[0033] The subject invention provides a concentrate comprising:

[0034] (a) 0.5 to 4 % by weight of an imidazole compound;

[0035] (b) 0.2 to 2 % by weight of a TIN etching activator selected from a phosphonic acid, phosphoric acid, or salts thereof;

[0036] (c) 0.02 to 1 % by weight of a polyethyleneimine;

[0037] (d) 0 to 5% by weight of a buffer capable of adjusting the pH to 7 to 10; and

[0038] (f) water; wherein the pH of the concentrate is of from 7 to 10, preferably 8 to 9.5.

[0039] In an embodiment the etching composition comprises:

[0040] (A) a concentrate according to anyone of the preceding claims; and

[0041] (B) an oxidizing agent, preferably a peroxide, particularly an aqueous solution of hydrogen peroxide in a mixing ratio A / B of from 10: 1 to 1 : 1 by weight.

[0042] The concentrate may particularly be used for preparing an etching composition for removing post etch residues from a substrate, the substrate comprising a surface of a ruthenium layer and of a TIN layer, the composition comprising:

[0043] (A) the concentrate as described herein; and

[0044] (B) the oxidizing agent, preferably a peroxide particularly preferably hydrogen peroxide; and

[0045] (C) water; in a mixing ratio A / (B-*C) of from 4:1 to 1 :3 by weight. Definitions

[0046] As used herein, "layer” means a part of a substrate that was separately disposed on the surface of a substrate and has a distinguishable composition with respect to adjacent layers.

[0047] The term "Cx” means that the respective group comprises x numbers of C atoms. The term "Cxto Cyalkyl" means alkyl with a number x to y of carbon atoms and, unless explicitly specified, includes unsubstituted linear, branched and cyclic alkyl. As used herein, "alkanediyl” refers to a diradical of linear, branched or cyclic alkanes or a combination thereof.

[0048] As used herein, "concentrate” means a composition or pre-mixture that is dilluted or admixed with at least one further compound to receive the final etching composition.

[0049] All percent, ppm or comparable values refer to the weight with respect to the total weight of the respective composition, in doubt to the etching composition, except where otherwise indicated. The terms “wt%” and "% by weight” are used herein synonymously.

[0050] A "post-etch residue” refers to a material remaining following a gas-phase plasma etching process, e.g., back-end-of- line ("BEOL”) dual damascene processing, or wet etching processes. A post-etch residue may be organic, organometallic, organosilicic, or inorganic in nature, for example, silicon-containing material, carbon-based organic material, and etch gas residues such as oxygen and fluorine. When ruthenium layers are etched, ruthenium etch residues such as rutheniumoxides may be present and are usually present. Depending on the substrates and the method of etching such ruthenium oxides may also contain other non-oxidic compounds.

[0051] If a component fits into multiple definitions of the constituents of the composition described herein, it is attributed to each constituent separately. For example, polyethyleneimine, as a base, may be sufficient to adjust the pH to the require range on its own, without the need for another specific pH adjusting agent.

[0052] All cited documents are incorporated herein by reference.

[0053] Imidazole compound

[0054] The cleaning composition comprises one or more imidazole compounds. The imidazole compounds ne in conjunction with an oxidizer can make polymers more water soluble. In addition, the heterocyclic amine can stabilize the oxidizer, enabling recycling and reuse of the composition.

[0055] Generally, the imidazole compounds may be (a) imidazole and any monomeric derivative thereof, (b) imidazoline and its derivatives, and (c) imidazolidine and its derivatives, particularly imidazolidinone and its derivatives. The imidazole compounds should be soluble in water.

[0056] Preferred imidazoles are 1-methylimidazole, 4-methylimidazole, and 1 ,2-dimethylimidazole. Preferred imidazolines (dihydroimidazoles) are 2-imidazoline (4,5-dihydro-1 H-imidazole) and 2-methyl-2-imidazoline.

[0057] Preferred imidazolidines are imidazolidine, 1-methylimidazolidine, 1-ethylimidazolidine, 2-wthylimidazolidine, 1- methy limid azol id i n-2-one, 1 , 3-d i methyl imidazol idine, 1 , 3-d i methyl-2-imid azol idinone .

[0058] Particularly preferred imidazole compounds are selected from 1 -methylimidazole and 1 ,3-Dimethyl-2-imidazolidinone.

[0059] The one or more imidazole compounds may be present in an amount of from about 0.5 to about 4 % by weight, preferably from about 0.75 to about 3.5 % by weight, most preferably from about 1 to about 3 % by weight.

[0060] TIN etching activator

[0061] The cleaning composition comprises one or more TIN etching activator selected from a phosphonic acid, phosphoric acid, and salts thereof.

[0062] Lowering the pH also decreases the oxidation potential of hydrogen peroxide, causing an unwanted drop in the TIN etch rate. In this field, a relatively high concentration of oxidants is usually necessary in order to achieve a sufficiently high metal hard mask etching rate. Surprisingly, activators that increase the TIN etch rate in the low-pH regime were found.

[0063] Preferred phosphonic acid are Ci to Ce alkylphonsphonic acids, such as but not limited to methylphosphonic acid (CH3PO(OH)2), ethylphosphonic acid (C2H5PO(OH)2), propylphosphonic acid (C3HzPO(OH)2), or butylphosphonic acid (C4HgPO(OH)2), aryl- or arylalkyl-phosphonic acids such as but not limited to phenylphosphonic acid (CeH5PO(OH)2), benzylphosphonic acid (CeH5CH2PO(OH)2) or naphthylphosphonic acid (CIOHZPO(OH)2), and di- or tri-phosphonic acids, such as but not limited to methylenediphosphonic acid (MDP), 1 -Hydroxyethylidene-1 ,1- Diphosphonic Acid (HEDP), or 1 -Hydroxyethylidene-1 , 1 ,2-triphosphonic acid (HETP). The phosphonic acid may be unsubstituted or substituted by hydroxy.

[0064] Preferred phosphoric acids are phosphoric acid, ammonium dihydrogen phosphate, diammonium hydrogen phosphate, ammonium phosphate, and mixtures thereof. Other salts with alkaline and alkaline earth metals may be used but are less preferred.

[0065] The TIN etching activator may be present in the composition in an amount of from about 0.2 to about 2 % by weight Preferably the composition of the invention comprises, of from 0.25 to 1 .8 % by weight, more preferably of from 0.3 to 1.5 % by weight, and most preferably of from 0.4 to 1 % by weight of at least one TIN etching activator.

[0066] Preferably, the TIN etching activator may be selected from the group consisting of 1 -Hydroxyethylidene-

[0067] 1 , 1 -diphosphonic acid (HEDP), phosphoric acid, and salts thereof. Polyethyleneimine (PEI)

[0068] The cleaning composition comprises one or more polyethyleneimine type corrosion inhibitors. The polyethyleneimine significantly reduces corrosion of TiN in the presence of ruthenium when removing post etch residues from the wafer surface.

[0069] It was found that the addition of polyethyleneimines lead to a low etching rate on blanket PVD ruthenium and particularly TiN compared to the composition without polyethyleneimines but still allows a good, preferably a complete removal of etch residues.

[0070] Polyethyleneimine backbones are to be understood as meaning compounds which consist of a saturated hydrocarbon chain with terminal amino functions which is interrupted by secondary and tertiary amino group. Such backbones may be linear or branched. Different polyethyleneimine backbones can of course be used in a mixture with one another.

[0071] Said backbones on comprise primary, secondary and tertiary amine nitrogen atoms connected by "linking" units. The backbone comprises essentially three types of units, and it needs to be emphasized that these groups may be distributed along the backbone in any order.

[0072] The units which make up the polyalkyleneimine backbones are (a) primary units having the formula:

[0073] [H2N-C2H4]- and -NH2which terminate the main backbone and any branching chains;

[0074] (b) secondary amine units having the formula: and (c) tertiary amine units having the formula: which are the branching points of the main and secondary backbone chains, AE1representing a continuation of the chain structure by branching. Continuation of the chain structure by branching here means that AE1may contain all primary, secondary and tertiary amine units described above except termination group -NH2. During the formation of the polyamine backbones cyclization may occur, therefore, an amount of cyclic polyamine may be present in the parent polyalkyleneimine backbone mixture. Each primary and secondary amine unit of the cyclic alkyleneimines undergoes modification by the addition of polyoxyalkylene units in the same manner as linear and branched polyalkyleneimines.

[0075] The polyalkyleneimines 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 backbones 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.

[0076] In addition, the polyalkyleneimine backbones may be partly substituted by alkylating agents. The substituents may be selected from a Ci to C12 alkyl, C2 to C12 alkenyl, C2 to C12 alkynyl, Ce to C20 alkylaryl, Ce to C20 arylalkyl, Ce to C20 aryl. Preferred substituents may be selected from a Ci to Ce alkyl, Ce to C12 alkylaryl, Ce to C12 arylalkyl, and Ce to C12 aryl. It is preferred that the aryl group is phenyl or naphthyl. Also the terminating groups [H2N-X1-1]- and -NH2 may be substituted by groups RL3.

[0077] Suitable examples for alkylating agents are organic compounds which contain active halogen atoms, such as arylalkyl halides, alkyl, alkenyl and alkynyl halides, and the like. Additionally, compounds such as alkyl sulfates, alkyl sultones, epoxides, and the like may also be used. Nonlimiting examples of corresponding alkylating agents comprise benzyl chloride, propane sultone, dimethyl sulphate, (3-chloro-2-hydroxypropyl) trimethyl ammonium chloride, or the like. Preference is given to using dimethyl sulphate and / or benzyl chloride.

[0078] In a preferred embodiment the polyethyleneimine is unsubstutituted. Depending on the pH of the composition, the amino groups in the polyethyleneimine may be present in its protonated form.

[0079] The mass average molecular mass Mwof the polyalkyleneimine may be of from about 800 g / mol to about 50 000 g / mol. The lower limit of the weight average molecular mass Mwof the polyalkyleneimine backbones is generally about 800 g / mol, preferably about 1 200 g / mol, more preferably about 1 500 g / mol. The upper limit of the weight average molecular mass Mwis generally about 50 000 g / mol, preferably about 25 000 g / mol, more preferably about 20 000 g / mol, most preferably about 10 000 g / mol. A particularly preferred range is of from 800 to 25.000 g / mol, most particularly 1000 to 4000 g / mol. The molecular mass may be determined by size exclusion chromatography like GPC using polymethylmethacrylate (PMMA) as standard and hexafluorisopropanol + 0.05% potassium trifluoracetate as eluent.

[0080] The polyethyleneimine may be present in an amount of from about 0.02 to about 1 % by weight, preferably from about 0.025 to about 0.9 % by weight, more preferably from about 0.3 to about 0.8 % by weight, even more preferably from about 0.4 to about 0.7 % by weight, most preferably from about 0.05 to about 0.5 % by weight. It was found that even low amounts of polyethyleneimine are sufficient to protect the TiN on the wafer surface. A further increase of the concentration is possible but does not significantly improve the corrosion inhibiting performance of the polyethyleneimine. pH adjusting agent

[0081] The cleaning composition may comprise a pH adjusting agent that is capable of adjusting, and ideally maintaining, the pH in a range from 7 to 10. In the simplest case one of the other components, particularly the TIN etching activator and / or the polyethylene imine may already be sufficient to adjust the pH so that a separate pH adjusting agent can be omitted.

[0082] Preferably a buffer system is used to adjust and maintain the pH at a predefined pH in the specified range.

[0083] Inorganic or organic buffer systems may be used.

[0084] Without limitation, the following buffer systems may be used in the specified pH range:

[0085] • Sodium dihydrogen phosphate (Na^PC ) and disodium hydrogen phosphate (Na2HPO4) can be used to prepare a phosphate buffer system. The pKa values of these components allow for buffering in the pH range of 6 to 8. Sodium may be exchanged by ammonium, a tetraalkylammonium or other alkaline or alkaline earth metal ions.

[0086] • Tris(hydroxymethyl)aminomethane (Tris) and hydrochloric acid (HCI) can be used to prepare a Tris buffer system. This buffer system is effective in the pH range of 7 to 9.

[0087] • Sodium carbonate (Na2CO3) and sodium hydrogencarbonate (NaHCOa) can be used to prepare a carbonate buffer system. This buffer system is effective in the pH range of 9 to 10. Sodium may be exchanged by ammonium, a tetraalkylammonium or other alkaline or alkaline earth metal ions.

[0088] • Good's buffers, such as MES (pH range 6.1-6.5), MOPS (pH range 6.5-7.9), and HEPPS (pH range 7.2-8.8), are a series of zwitterionic buffers that can maintain pH within specific ranges.

[0089] A preferred buffer is a phosphate buffer consisting of ammonium dihydrogen phosphate (NH4H2PO4) and diammonium hydrogen phosphate ((NH4)2HPC>4). This may advantageously be prepared by mixing ammonium hydroxide and phosphoric acid in amounts to get the predefined pH in combination with the other ingredients.

[0090] Preferably the pH adjusting agent or buffer system is capable of adjusting or maintaining the pH of the etching composition in the range of from about 6 to about 10, preferably from about 6.5 to about 9, most preferably from about 7 to about 8.5.

[0091] If used, the amout of the pH adjusting agent is usually from about 0.01% to about 5% by weight, preferably from about 0.1 to about 4 % by weight, most preferably from about 0.5 to about 2.5 % by weight. In one embodiment no other pH adusting agents besides the imidazol compound, the TIN etching activator, and the polyethyleneimine are present. In another embodiment the pH adusting agent or buffer differs from either or all of the imidazol compound, the TIN etching activator, and the polyethyleneimine. Most preferably an ammonium dihydrogen phosphate I diammonium hydrogen phosphate buffer is used in addition to the other constituents of the composition that can be attributed to the pH adjusting agent.

[0092] Water

[0093] The concentrates like the etching compositions of the present invention are aqueous-based and, thus, comprise water. Water has several functions such as, for example, to dissolve one or more components of the composition, as a carrier of the components, as an aid in the removal of residue, as a viscosity modifier of the composition, and as a diluent. Preferably, the water employed in the composition is de-ionized (DI) water. The ranges of water described in the next paragraph include all of the water in the composition from any source.

[0094] For most applications, the amount of water in the concentrate (in % by weight) will be present in a range with start and end points selected from the following group of numbers: 70, 72, 74, 76, 78, 80, 82, 84, 86, 88, 90, 91, 92, 93, 94, 95, 96, 98, 99, 99.28. Preferred examples of the ranges of water that may be used in the composition include, for examples, from about 75 to about 99 % by weight, or about 80 to about 98% by weight of water; or from about 92 to about 98,5 % by weight, or from about 94 to about 98 % by weight. Still other preferred embodiments of the present invention may include water in an amount to achieve the desired weight percent of the other ingredients.

[0095] In the final composition, i.e. in the concentrate diluted with the solution of the oxidizer in water, the amount of water in the etching composition will be present in a range with start and end points selected from the following group of numbers: 50, 55, 60, 65, 70, 72, 74, 76, 78, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 99. Examples of the ranges of water that may be used in the composition include, for examples, from about 70 to about 980 % by weight, or about 75 to about 95% by weight of water; or from about 75 to about 90 % by weight, or from about 77 to about 85 % by weight,. Still other preferred embodiments of the present invention may include water in an amount to achieve the desired weight percent of the other ingredients.

[0096] Oxidizing agent

[0097] The etching composition according to the invention comprises an oxidizing agent. The oxidizing agent, also referred to as oxidizer, may be any oxidizing agent that is capable of oxidizing the etching residues to be removed without jeopardizing the substrate to be cleaned.

[0098] Oxidizing agents contemplated herein include, but are not limited to, hydrogen peroxide, FeCla, FeFs, FefNOsjs, Sr(NO3)2, C0F3, MnFa, oxone (2KHSO5 KHSO4 K2SO4), periodic acid, iodic acid, vanadium (V) oxide, vanadium (I V, V) oxide, ammonium vanadate, ammonium peroxymonosulfate, ammonium chlorite, ammonium chlorate, ammonium iodate, ammonium nitrate, ammonium perborate, ammonium perchlorate, ammonium periodate, ammonium persulfate, ammonium hypochlorite, ammonium hypobromite, ammonium tungstate, sodium persulfate, sodium hypochlorite, sodium perborate, sodium hypobromite, potassium iodate, potassium permanganate, potassium persulfate, nitric acid, potassium persulfate, potassium hypochlorite, tetramethylammonium chlorite, tetramethylammonium chlorate, tetramethylammonium iodate, tetramethylammonium perborate, tetramethylammonium perchlorate, tetramethylammonium periodate, tetramethylammonium persulfate, tetrabutylammonium peroxymonosulfate, peroxymonosulfuric acid, ferric nitrate, urea hydrogen peroxide, peracetic acid, methyl-1,4-benzoquinone (MBQ), 1,4-benzoquinone (BQ), 1,2-benzoquinone, 2,6-dichloro-1,4-benzoquinone (DCBQ), toluquinone, 2,6- dimethyl-1, 4-benzoquinone (DMBQ), chloranil, alloxan, N-methylmorpholine N-oxide, trimethylamine N-oxide, and combinations thereof.

[0099] The oxidizing species is preferably introduced to the concentrate at the manufacturer, prior to introduction of the etching composition to the device wafer, or alternatively at the device wafer, i.e., in situ.

[0100] Preferably the oxidizing agent comprises or consists of a peroxide. Useful peroxides may be but are not limited to hydrogen peroxide or peroxymonosulfuric acid and organic acid peroxides like peroxyacetic acid, and their salts.

[0101] The most preferred oxidizing agent is hydrogen peroxide, preferably it is used as aqueous solution in a concentration of more than 30% by weight. Usually, 31% hydrogen peroxide available in the market is used. Preferably the hydrogen peroxide has electronic grade quality.

[0102] The absolute concentration of the oxidizer in the etching composition may be of from 10 to 20 % by weight, preferably from 11 to 19 % by weight, more preferably from 12 to 18.5 by weight, most preferably from 14 to 18 % by weight.

[0103] Water-miscible organic solvent

[0104] The cleaning composition may comprise one or more water-miscible organic solvents. These may help dissolving other components in the composition and improving the efficiency and solubility of organic residue removal from the wafer surface.

[0105] The term "water-miscible organic solvent” in the context of the present invention preferably means that an organic solvent fulfilling this requirement is miscible with water at least in a 1 : 1 (w / w) ratio at 20 °C and ambient pressure.

[0106] Examples of water-miscible organic solvents that can be employed are

[0107] (a) ethers, such as but not limited to tripropylene glycol methyl ether, propylene glycol propyl ether, diethylene gycol n-butyl ether (BDG), dipropylene glycol methyl ether (DPM);

[0108] (b) sulfur-containing solvents:

[0109] (I) sulfones, such as but not limited to sulfolane;

[0110] (II) sulfoxides, such as but not limited to dimethylsulfoxide (DMSO);

[0111] (c) alcohols, such as but not limited to tetrahydrofurfuryl alcohol or linear or branched C2 to Ce alkanols like ethanol, n-propanol or isopropanol;

[0112] (d) 4-methylmorpholine-4-oxide, trimethylamine-N-oxide, triethylamine-N-oxide, triethanolamine-N-oxide, pyridine- N-oxide, N-formyl-morpholine, N-ethylmorpholine-N-oxide, N-ethylpyrrolidine-N-oxide; or

[0113] (e) mixtures thereof.

[0114] The water-miscible organic solvent may be protic or aprotic. Preferably the water-miscible organic solvent is aprotic. Preferred solvents are dimethylsulfoxide, diethylsulfoxide, methylethyl-sulfoxide, dipropyl sulfoxide, diphenylsulfoxide, methylphenylsulfoxide and 1,1 '-dihydroxyphenyl sulfoxide, and sulfolane, or mixtures thereof. Most preferred solvents are dimethylsulfoxide, sulfolane, and a mixture thereof.

[0115] For most applications, the amount of water-miscible organic solvent in the composition may be in a range having start and end points selected from the following list of weight percents: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10.

[0116] In individual cases, a composition according to the invention as defined herein may further comprise as an optional additional component: One or more water-miscible organic solvents, preferably selected from the group consisting of tetrahydrofuran (THF), N-methylpyrrolidone (NMP), dimethyl formamide (DMF), dimethyl sulfoxide (DMSO), ethanol, isopropanol, butyldiglycol, butylglycol, 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.

[0117] In some preferred embodiments the concentrate and / or the etching compositions of this invention will be free of or substantially free of any or all of the above-listed water-miscible organic solvents. In some other preferred embodiments the concentrate and / or the etching compositions of this invention will be free of or substantially free of any solvents besides water.

[0118] Chelating agents

[0119] The cleaning composition may optionally comprise one or more chelating agents.

[0120] Preferred chelating agents are of 1 ,2-cyclohexylenedinitrilotetraacetic acid, 1 ,1 , 1 ,5,5,5-hexafluoro-2,4-pentane-dione, acetylacetonate, 2,2'-azanediyldiacetic acid, ethylenediaminetetra-acetic acid, etidronic acid, methanesulfonic acid, acetylacetone, 1,1,1-trifluoro-2,4-pentanedione, 1,4-benzoquinone, 8-hydroxyquinoline, salicyli-dene aniline; tetrachloro-1,4-benzoquinone, 2-(2-hydroxyphenyl)-benzoxazol, 2-(2-hydroxyphenyl)-benzothiazole, hydroxyquinoline sulfonic acid, sulfosali-cylic acid, salicylic acid, pyridine, 2-ethylpyridine, 2-methoxypyridine, 3- methoxypyridine, 2-picoline, dimethylpyridine, piperidine, piperazine, ethylamine, methylamine, isobutylamine, tertbutylamine, tributylamine, dipropylamine, dimethylamine, diglycol amine, methyldiethanolamine, pyrrole, isoxazole, bipyridine, py-rimidine, pyrazine, pyridazine, quinoline, isoquinoline, indole, 1 -methylimidazole, diisopropylamine, diisobutylamine, aniline, pentamethyldi-ethylenetriamine, acetoacetamide, ammonium carbamate, ammonium pyrrolidinedithiocarbamate, dimethyl malonate, methyl acetoacetate, N-methyl acetoacetamide, tetramethylammonium thiobenzoate, 2,2,6,6-tetramethyl-3,5-heptanedione, tetramethylthiuram disulfide, lactic acid, ammonium lactate, formic acid, propionic acid, gamma-butyrolactone, and mixtures thereof;

[0121] The chelating agent may be 1 ,2-cyclohexylenedinitrilotetraacetic acid (CDTA) or may comprise CDTA as well as one or more of the other chelating agents above.

[0122] A composition according to the invention as defined herein is also preferred wherein the amount of the one or more chelating agents present is of from about 0.01 to about 4 % by weight, preferably of from about 0.02 to about 1 % by weight, more preferably of from about 0.05 to about 0.8 % by weight, based on the total weight of the composition. In some preferred embodiments the concentrate and / or the etching compositions of this invention will be free of or substantially free of any or all of the above-listed chelating agents.

[0123] Surfactants

[0124] The composition may also further comprise one or more surfactants.

[0125] Preferred surfactants are selected from the group consisting of

[0126] (i) anionic surfactants, 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), perfluorooctanesulfonate, perfluorobutanesulfonate, perfluorononanoate and perfluorooctanoate; alkyl-aryl ether phosphates and alkyl ether phosphates;

[0127] (II) zwitterionic surfactants, preferably selected from the group consisting of (3-[(3- cholamidopropyl)dimethylammonio]-1 -propanesulfonate) ("CHAPS”), cocamidopropyl hydroxysultaine (CAS RN 68139-30-0), {[3-(dodecanoylamino)propyl](dimethyl)-ammonio}acetate, phosphatidylserine, phosphatidylethanolamine, phosphatidylcholine; and

[0128] (ill) non-ionic surfactants, preferably selected from the group consisting of glucoside alkyl ethers, glycerol alkyl ethers, cocamide ethanolamines and lauryldimethylaminoxide.

[0129] More preferred surfactants in compositions according to the invention are or comprise perfluorinated, N-substituted alkylsulfonamide ammonium salts. Preferred surfactants (E) in compositions according to the invention do not comprise metals or metal ions.

[0130] A composition according to the invention as defined herein is also preferred wherein, if present, the amount of the one or more surfactants of the surfactant present is of from about 0.0001 to about 1 % by weight, preferably of from about 0.0005 to about 0.5 % by weight, more preferably in an amount of from about 0.001 to about 0.01 % by weight, based on the total weight of the composition.

[0131] Specific surfactants for use in the compositions described herein include, but not limited to, bis(2- ethylhexyl)phosphate, perfluoroheptanoic acid, prefluorodecanoic acid, trifluoromethanesulfonic acid, phosphonoacetic acid, dodecenylsuccinic acid, dioctadecyl hydrogen phosphate, octadecyl dihydrogen phosphate, dodecylamine, dodecenylsuccinic acid monodiethanol amide, 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, Brij 35), dodecenylsuccinic acid monodiethanol amide (DSDA, Sanyo), ethylenediamine tetrakis(ethoxylate-block- propoxylate) tetrol (Tetronic 90R4), polyethylene glycols (e.g., PEG 400), polypropylene glycols, polyethylene or polypropylene glycol ethers, block copolymers based on ethylene oxide and propylene oxide (Newpole PE-68 (Sanyo), Pluronic L31, Pluronic 31 R1, Pluronic L61, Pluronic F-127) (Dynol 607), polyoxypropylene sucrose ether (SN008S, Sanyo), t-octylphenoxypolyethoxyethanol (Triton X100), 10-ethoxy-9,9-dimethyldecan-1 -amine (TRITON® CF-32), Polyoxyethylene (9) nonylphenylether, branched (IGEPAL CO-250), polyoxyethylene (40) nonylphenylether, branched (IGEPAL CO-890), polyoxyethylene sorbitol hexaoleate, polyoxyethylene sorbitol tetraoleate, polyethylene glycol sorbitan monooleate (Tween 80), sorbitan monooleate (Span 80), a combination of Tween 80 and Span 80, alcohol alkoxylates (e.g., Plurafac RA-20), alkyl-polyglucoside, ethyl perfluorobutyrate, 1 , 1 ,3,3,5,5-hexamethyl-1 ,5- bis[2-(5-norbornen-2-yl)ethyl]trisiloxane, monomeric octadecylsilane derivatives such as SIS6952.0 (Siliclad, Gelest), siloxane modified polysilazane such as PP1-SG10 Siliclad Glide 10 (Gelest), silicone-polyether copolymers such as Silwet L-77 (Setre Chemical Company), Silwet ECO Spreader Momentive), and ethoxylated fluorosurfactants (ZONYL® FSC-100, ZONYL® FSN-100); cetyl trimethylammonium bromide (CTAB), heptadecanefluorooctane sulfonic acid, tetraethylammonium, stearyl trimethylammonium chloride (Econol TMS-28, Sanyo), 4-(4- diethylaminophenylazo)-1 -(4-nitrobenzyl)pyridium bromide, cetylpyridinium chloride monohydrate, benzalkonium chloride, benzethonium chloride benzyldimethyldodecylammonium chloride, benzyldimethylhexadecylammonium chloride, hexadecyltrimethylammonium bromide, dimethyldioctadecylammonium chloride, dodecyltrimethylammonium chloride, hexadecyltrimethylammonium p-toluenesulfonate, didodecyldimethylammonium bromide, dehydrogenated tallow) dimethylammonium chloride, tetraheptylammonium bromide, tetrakis(decyl)ammonium bromide, Aliquat® 336 and oxyphenonium bromide, guanidine hydrochloride (C(NH2)3CI) or triflate salts such as tetrabutylammonium trifluoromethanesulfonate, dimethyldioctadecylammonium chloride, dimethyldihexadecylammonium bromide and dehydrogenated tallow)dimethylammonium chloride (e.g., Arquad 2HT- 75, Akzo Nobel), bromide-containing surfactants, such as, 1 -hexadecyltrimethylammonium bromide.

[0132] In some preferred embodiments the concentrate and / or the etching compositions of this invention will be free of or substantially free of any or all of the above-listed surfactants.

[0133] Biocides

[0134] The concentrate may further optionally contain at least one biocide, for example one biocide. In general, the biocide is a compound which deters, renders harmless, or exerts a controlling effect on any harmful organism by chemical or biological means. Preferably, the biocide is a quaternary ammonium compound, an isothiazolinone- based compound, an N-substituted diazenium dioxide, or an N'-hydroxy-diazenium oxide salt. If present, the biocide can be contained in varying amounts. If present, the amount of the biocide is preferably not more than 0.5 % by weight, more preferably not more than 0.1 wt.%, most preferably not more than 0.05 % by weight, particularly not more than 0.02 % by weight, for example not more than 0.008 % by weight, based on the total weight of the corresponding composition. If present, the amount of the biocide is preferably at least 0.0001 % by weight, more preferably at least 0.0005 % by weight, most preferably at least 0.001 % by weight, particularly at least 0.003 % by weight, for example at least 0.006 % by weight, based on the total weight of the corresponding composition. Also H2O2 may be used as a biocide if used in the low amounts specified above.

[0135] Composition

[0136] The concentrate is typically prepared by mixing the components together in a vessel at room temperature until all solids have dissolved in the aqueous-based medium. A preferred concentrate comprises, essentially consists of or consists of:

[0137] (a) 0.5 to 4 % by weight, preferably 1 to 3 % by weight of the imidazole compound;

[0138] (b) 0.2 to 3 % by weight, preferably 1 to 2 % by weight of the TIN etching activator;

[0139] (c) 0.02 to 1 % by weight, preferably 0.05 to 0.5 % by weight of the polyethyleneimine;

[0140] (d) 0 or 0.1 or 5% by weight, preferably 0.5 to 2 % by weight of the buffer;

[0141] (e) 0 or 0.01 to 3 % by weight of an additive selected from a water-miscible solvent, a chelating agent, a surfactant, and a biocide;

[0142] (f) rest water; wherein the pH of the concentrate is of from 7 to 10, preferably 8 to 9.5.

[0143] A particularly preferred concentrate comprises, essentially consists of or consists of:

[0144] (a) 0.5 to 4 % by weight, preferably 1 to 3 % by weight of the imidazole compound;

[0145] (b) 0.2 to 3 % by weight, preferably 1 to 2 % by weight of the TIN etching activator;

[0146] (c) 0.02 to 1 % by weight, preferably 0.05 to 0.5 % by weight of the polyethyleneimine;

[0147] (d) 0 or 0.1 or 5% by weight, preferably 0.5 to 2 % by weight of the buffer;

[0148] (e) 0 or 0.01 to 2 % by weight of an additive selected from a chelating agent, a surfactant, and a biocide;

[0149] (f) rest water; wherein the pH of the concentrate is of from 7 to 11 , preferably 8 to.10.

[0150] The invention further provides an etching composition for removing post etch residues from a substrate, the substrate comprising a surface of a ruthenium layer and of a TIN layer. The etching composition is received by admixing the concentrate with the oxidizing agent and, if applicable, water prior to use in a mixing ratio concentrate:oxidizing agent of 10:1 to 1 :1 by weight.

[0151] In an embodiment the etching composition comprises:

[0152] (A) a concentrate according to anyone of the preceding claims; and

[0153] (B) an oxidizing agent, preferably a peroxide in a mixing ratio A / B of from 10: 1 to 1 : 1 by weight.

[0154] Preferably the mixing ratio A / B is from about 9:1 to about 6:5 by weight, more preferably from about 6:1 to about 3:2 by weight, most preferably from about 9:2 to about 2:1 by weight.

[0155] Preferably the etching composition comprises, essentially consists of, or consist of:

[0156] (A) a concentrate according to anyone of the preceding claims;

[0157] (B) an oxidizing agent, preferably a peroxide, particularly preferably hydrogen peroxide; and

[0158] (C) water; in a mixing ratio A / (B-*C) of from 4:1 to 1 :3 by weight.

[0159] The water may be introduced as the solvent for the oxidizer or added separately. Preferably the mixing ratio A / (B+C) is from about 3:1 to about 2:5 by weight, more preferably from about 2:1 to about 1 :2 by weight, most preferably from about 3:2 to about 2:3 by weight.

[0160] Preferably the ratio between the oxidizer B and water C is of from about 1 :1 to about 1:3, preferably from 2:3 to 2:5. Most preferably 31% hydrogen peroxide is used as the components B + C.

[0161] Usually, the pH of the etching composition may be in the range of from about 6 to about 10. In a preferred embodiment the pH of the etching composition is from about 6.5 to about 9.5, more preferably from about 7 to about 9, most preferably from about 7 to about 8.5.

[0162] Other commonly known components such as dyes, chemical modifiers, biocides, etc. can be included in the cleaning composition in conventional amounts, for example, amounts up to a total of about 1 or 5 or 10 % by weight of the composition to the extent that they do not adversely affect the performance of the composition.

[0163] Alternatively, the cleaning compositions may be free or substantially free of any or all of dyes, chemical modifiers besides those described above, and biocides.

[0164] An preferred etching composition comprises, essentially consists of, or consits of:

[0165] (a) 0.25 to 2 %, preferably 0.5 to 1 % by weight of the imidazole compound;

[0166] (b) 0.1 to 1.5 %, preferably 0.2 to 1 % by weight of the activator;

[0167] (c) 0.01 to 0.5 %, preferably 0.025 to 0.25 % by weight of the polyethyleneimine;

[0168] (d) 0 or 0.05 to 3%, preferably 0.1 to 2.5 % by weight of the buffer

[0169] (e) 10 to 20 %, preferably 12 to 18 % by weight of the oxidizing agent, preferably H2O2;

[0170] (g) optionally an additive selected from a water-miscible solvent, a chelating agent, a surfactant, and a biocide;

[0171] (f) rest water.

[0172] An particularly preferred etching composition comprises, essentially consists of, or consits of:

[0173] (a) 0.25 to 2 %, preferably 0.5 to 1 % by weight of the imidazole compound;

[0174] (b) 0.1 to 1.5 %, preferably 0.2 to 1 % by weight of the activator;

[0175] (c) 0.01 to 0.5 %, preferably 0.025 to 0.25 % by weight of the polyethyleneimine;

[0176] (d) 0 or 0.05 to 3%, preferably 0.1 to 2.5 % by weight of the buffer;

[0177] (e) 10 to 20 %, preferably 12 to 18 % by weight of the oxidizing agent;

[0178] (g) optionally an additive selected from a chelating agent, a surfactant, and a biocide;

[0179] (f) rest water.

[0180] "Essentially” in this context means that the content of any other compounds except the specifically mentioned ones are below 1 % by weight, preferably below 0.1 % by weight, even more preferably below 0.01 % by weight, most preferably below the detection limit.

[0181] A composition according to the invention as defined herein is specifically preferred wherein the composition consists of the compounds as defined herein and to be defined based on the examples. Application

[0182] The etching composition can preferably be used for etching ruthenium layers in the presence of TIN adhesion layers. The adhesion layer is required due to poor adhesion of Ru on standard dielectric materials such as SiC>2 or SiaN4.

[0183] In another aspect there is provided a process of removing post etch residues from a substrate, the substrate comprising a surface of a ruthenium layer and of a TIN layer, the process comprising:

[0184] (a) providing a microelectronic device surface that includes the surface of the ruthenium layer, the TIN layer, and post etch residues thereon;

[0185] (b) providing an etching composition according to anyone of claim 10 to 13;

[0186] (c) contacting the surface with the composition for a time and at a temperature effective to remove the post etch residues while not compromizing the ruthenium layer and the TIN layer.

[0187] Without limitation, such layers may be present conducting lines of semidamascene structures as depicted in Fig. 1 and described in more detail, e.g., in J. Vac. Sci. Technol. B 40(3) May / Jun 2022. Fig. 1 shows a semidamascene structures comprising (from bottom to top) a SiC>2 layer 1 onto which a Ru layer 2 is deposited. For a better adhesion below and above the Ru layer respective TIN layers 3 are used.

[0188] It will be appreciated that it is common practice to make concentrated forms of the compositions to be diluted prior to use. For example, the compositions may be manufactured as a concentrate and thereafter diluted with the oxidizing agent or other components at the manufacturer, before use, and / or during use.

[0189] In the use of the compositions described herein, the composition typically is contacted with the device structure for a sufficient time of from about 1 minute to about 200 minutes, preferably about 1 minute to about 10 minutes, at temperature in a range of from about 30 °C to about 90 °C, preferably about 35 °C to about 60 °C. Such contacting times and temperatures are illustrative, and any other suitable time and temperature conditions may be employed that are efficacious to achieve the required removal selectivity.

[0190] Following the achievement of the desired etching action, the composition can be readily removed from the microelectronic device to which it has previously been applied, e.g., by rinse, wash, or other removal step(s), as may be desired and efficacious in a given end use application of the compositions of the present invention. For example, the device may be rinsed with a rinse solution including deionized water, an organic solvent, and / or dried (e.g., spindry, N2, vapor-dry etc.).

[0191] Preferably the Ru etch rates of the etching compositions are 0.1 nm / min or below, preferably 0.01 nm / min or below.

[0192] Preferably the TIN etch rates of the etching compositions are 50 nm / min or below, preferably 40 nm / min or below.

[0193] After the contacting step is an optional rinsing step. The rinsing step may be carried out by any suitable means, for example, rinsing the substrate with de-ionized water by immersion or spray techniques. In preferred embodiments, the rinsing step may be carried out employing a mixture of de-ionized water and an organic solvent such as, for example, isopropanol.

[0194] After the contacting step and the optional rinsing step is an optional drying step that is carried out by any suitable means, for example, isopropanol (IPA) vapor drying, heat, or by centripetal force.

[0195] The etching composition described herein may be advantagoulsy used in a process for the manufacture of a semiconductor device, comprising the step of selectively reving post etch residues from a surface of a microelectronic device comprising a molybdenum layer as described herein.

[0196] The following examples shall further illustrate the present invention without restricting the scope of this invention.

[0197] Examples

[0198] Etching experiments were conducted on blanket CVD Ru and ALD TIN substrates having 200 and 100 Angstrom respectively. 18 nm metal pitch cleaning experiments were carried out on semi-damascene coupons in (Fig. 1)

[0199] 100 ml of etching solution was placed into a 150 ml beaker and the beaker was placed into a temperature-controlled water bath. A 2.5 cm x 2.5 cm coupon of the respective substrate was then dipped into the test solution at desired temperature while the solutions was stirred with a 250-rpm speed. Both blanket and semi-damascene coupon etching were carried out 2 min followed by DIW rinsing for 30 seconds and then the coupons were dried with an N2 gun. The blanket coupon and semi-damascene etching experiments were carried out at 55°C.

[0200] The thickness of the blanket coupons was determined by XRF measurements. The semi-damascene coupons were characterized with TEM for assessing residue cleaning capability and attack of the TIN layers in Figure 1.

[0201] The etching rates were calculated according to the following formula:

[0202] 100 g of a comparative concentrate solution C1.1 was prepared by mixing the following components:

[0203] 1. 95.4 g of DIW

[0204] 2. 1 g of N-methylimidazole (from BASF)

[0205] 3. 1 g of 1 ,3-dimethyl-2-imidazolidinone (from Alfa Aesar)

[0206] 4. 0.6 g of ammonium hydroxide (from BASF)

[0207] 5. 0.2 g of 5-methylbenzotriazole (from Alfa Aesar) 6. 0.2 g of 5-chlorobenzotriazole (from TCI)

[0208] 7. 0.62 g of HEDP (from Sigma-Aldrich)

[0209] 8. 0.95 g of H3PO4 (from BASF)

[0210] The concentrate was stirred with a magnetic stirring bar with a speed of 100 rpm during the mixing. After all the components were dissolved, the concentrate was mixed 1 :1 wt% with 31 wt.% of H2O2 right before starting the etching experiments.

[0211] Example 1

[0212] The Ru and TiN etching rates (ER) of the etching solutions with different concentrations of polyethyleneimine (PEI) was determined at 55 °C on blanket coupons. The composition with the concentrations of the components in the concentrate and the etching results are depicted in table 1.

[0213] Table 1

[0214] Comparative example C1.1 that does not comprise any TIN etching inhibitor results in a significantly higher TiN etching rate than any formulation which comprises PEI at different concentrations.

[0215] Example 2

[0216] The Ru and TiN etching rates (ER) of solutions with different molecular masses of polyethyleneimine (PEI) was determined at 55 °C on blanket coupons. The composition with the concentrations of the components in the concentrate and the etching results are depicted in table 2. Table 2

[0217] The results show that all solutions with PEI of different molecular masses show a reduced etching of TIN. Example 3

[0218] The Ru and TIN etching rates (ER) of solutions with no HEDP and different HEDP concentrations were measured.

[0219] The composition with the concentrations of the components in the concentrate and the etching results are depicted in table 3.

[0220] Table 3

[0221] The results depicted in table 3 show that HEDP has no significant influence on the etch rates.

Claims

Claims1 . A concentrate for preparing a composition for removing post etch residues from a substrate, the substrate comprising a surface of a ruthenium layer (2) and of a TIN (3) layer, the concentrate comprising:(a) 0.5 to 4 % by weight of an imidazole compound;(b) 0.2 to 3 % by weight of a TIN etching activator selected from a phosphonic acid, phosphoric acid, or salts thereof;(c) 0.02 to 1 % by weight of a polyethyleneimine;(d) 0 to 5 % by weight of a pH adjusting agent capable of adjusting the pH to 7 to 10; and(f) water; wherein the pH of the concentrate is of from 7 to 10, preferably 8 to 9.5.

2. The concentrate according to claim 1, wherein the imidazole compound is selected from N-methylimidazole and 1 , 3-D I methy l-2-imid azol idinone .

3. The concentrate according to anyone of claims 1 or 2, wherein the imidazole compound is present in an amount of from 1 to 3% by weight.

4. The concentrate according to anyone of the preceding claims, wherein the TIN etching activator is selected from 1 -Hydroxyethylidene-1 , 1 -diphosphonic acid (HEDP), phosphoric acid, and salts thereof.

5. The concentrate according to anyone of the preceding claims, wherein the TIN etching activator is present in an amount of from 0.5 to 1 .5% by weight.

6. The composition according to anyone of the preceding claims, wherein the polyethyleneimine has a weight average molecular mass of from 600 to 50 000 g / mol, preferably of from 800 to 25.000 g / mol.

7. The concentrate according to anyone of the preceding claims, wherein the polyethyleneimine is present in an amount of from 0.05 to 0.5% by weight.

8. The concentrate according to anyone of the preceding claims, wherein the pH adjusting agent is a buffer comprisinga mixture of ammonium hydroxide and phosphoric acid.

9. The concentrate according to anyone of the preceding claims, consisting essentially of(a) 0.5 to 4 % by weight of the imidazole compound;(b) 0.2 to 2 % by weight of the TIN etching activator;(c) 0.02 to 1 % by weight of the polyethyleneimine;(d) 0 or 0.1 or 3% by weight of the pH adjusting agent;(f) rest water;10. An etching composition for removing post etch residues from a substrate, the substrate comprising a surface of a ruthenium layer and of a TIN layer, the composition comprising:(A) the concentrate according to anyone of the preceding claims;(B) an oxidizing agent in a mixing ratio A / B of from 10: 1 to 1 : 1 by weight.

11. The etching composition according to claim 10, comprising:(A) the concentrate according to anyone of claims 1 to 9;(B) an oxidizing agent, and(C) water; in a mixing ratio A / (B-*C) of from 4:1 to 1 :3 by weight.

12. The etching composition according to anyone of claim 10 or 11 , wherein the oxidizing agent is a peroxide, particularly hydrogen peroxide.

13. The etching composition according to anyone of claims 10 to 12, wherein the oxidizing agent is hydrogen peroxide.

14. The etching composition according to anyone of claims 10 or 13, comprising:(a) 0.25 to 2 % by weight of the imidazole compound;(b) 0.1 to 1.5 % by weight of the activator;(c) 0.01 to 0.5 % by weight of the polyethyleneimine;(d) 0 or 0.05 to 2.5% by weight of the pH adjusting agent;(e) 10 to 20 % by weight of the oxidizing agent; and(f) water; wherein the pH of the etching composition is of from 6.5 to 9, preferably 7 to 8.5.

15. The etching composition according to claim 14, consisting essentially of:(a) 0.25 to 2 % by weight of the imidazole compound;(b) 0.1 to 1.5 % by weight of the activator;(c) 0.01 to 0.5 % by weight of the polyethyleneimine;(d) 0.05 to 2% by weight of the pH adjusting agent;(e) 10 to 20 % by weight of the oxidizing agent; and(f) rest water.

16. Use of an etching composition according to anyone of claims 10 to 15 for removing post etch residues from a semiconductor substrate comprising a surface of a ruthenium layer (2) and a TIN layer (3).

17. A process of removing post etch residues from a substrate, the substrate comprising a surface of a ruthenium layer (2) and of a TIN layer (3), the process comprising:(a) providing a microelectronic device surface that includes the surface of the ruthenium layer (2), the TIN layer (3), and post etch residues thereon;(b) providing an etching composition according to anyone of claim 10 to 15;(c) contacting the surface with the composition for a time and at a temperature effective to remove the post etch residues while not compromizing the ruthenium layer (2) and the TIN layer (3).

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