RS904A - ALKALINE MIXTURES WITHOUT AMMONIUM FOR CLEANING MICROELECTRONICS WITH BETTER COMPATIBILITY, BY SUBSTRATE - Google Patents

Abstract

Ammonia-free cleaning preparations for cleaning microelectronic substrates, particularly those cleaning preparations which are useful because they have better compatibility with microelectronic substrates, characterized by sensitive porous low-k and high-k dielectrics, and metallization with copper. Cleaning preparations for removing photoprotective layers, cleaning residues of organic, organometallic and inorganic compounds generated by plasma and for cleaning residues from planarization procedures. The cleaning composition contains one or more strong, non-ammonia-producing bases having non-nucleophilic, positively charged counterions and one or more sterically hindered amide solvents.

Description

ALKALINE CLEANING PREPARATIONS WITHOUT AMMONIA

MlKROELEKTRONIK, WITH BETTER COMPATIBILITY

BY SUBSTRATE

This invention relates to ammonia-free cleaning compositions for cleaning microelectronic substrates, and particularly to those cleaning compositions which are useful because they have improved compatibility with microelectronic substrates characterized by sensitive, porous dielectrics with low and high metallization with copper. This invention also relates to the use of these cleaning preparations in removing the photoprotective layer, cleaning residues of organic, organometallic and inorganic compounds generated by plasma and cleaning residues from planarization processes, such as chemical mechanical polishing (CMP), and from additives in residues of dense planarization suspension.

Many cleaning agents and photoprotective layer removal agents have been proposed for use in the field of microelectronics, as the output or final stage of the cleaning production line. In the manufacturing process, a thin film of photoprotective material is deposited on a wafer as a substrate, and then an image of an electronic circuit diagram is transferred onto this thin film. After baking, the unpolymerized protective layer is removed with a developer for the photoprotective layer material. The resulting image is transferred to the substrate material, which is usually a dielectric or metal, via etching gases from a reactive plasma or chemical etching solution. Etching gases or chemical etching solutions selectively attack the unprotected surface of the photoprotective layer on the substrate. As a result of the plasma etching process, by-products of the photoprotective layer, etching gas and etched material are deposited as residues in the vicinity or on the side walls of the etched openings on the substrate.

Additionally, upon completion of the etching step, the protective layer mask must be removed from the protected surface of the wafer so that the final polishing operation can be performed. This can be done in the plasma burn step, using suitable plasma burn gases, or using wet chemical stripping agents. Finding a suitable cleaning agent to remove this protective layer mask material without adversely affecting the metal circuit, e.g. by corroding, dissolving or rounding, has also proven problematic.

As the level of integration in microelectronics manufacturing has increased and the dimensions of patterned microelectronic devices have decreased, the need for copper metallizations and low-Ki high-K porous dielectrics has increased in the prior art. These materials present additional challenges in finding acceptable cleaning agents. Many of the process technology preparations previously developed for "traditional" or "conventional" devices, containing Al/SiO 2 or Al(Cu)/SiO 2 structures, cannot be used for low-K or high-K metallized copper dielectric structures. For example, strippers or residue removers, which are used successfully to clean devices with Al metallizations, are practically useless in those with copper metallizations. Similarly, many copper/low-Kniss strippers are suitable for Al metallized devices, unless significant adjustments are made to the compositions. The removal of these etching and/or burning residues, left behind after the etching and/or burning process, has proven to be problematic. Failure to completely remove or neutralize these residues can lead to moisture absorption and the formation of unwanted materials, which can cause corrosion on metal structures. Electronic circuit materials corrode with undesirable materials and create discontinuities in the circuit, increasing unwanted electrical resistance.

Today's finishing cleaners show a wide range of compatibility with some sensitive dielectrics and metallizations, ranging from complete unacceptability to marginally satisfactory acceptability. Many of today's strippers or residue cleaners are not acceptable for modern bridging materials, such as low-Ki copper metallization dielectrics. In addition, typical alkaline cleaning solutions in use are excessively aggressive towards low-K and high-K dielectrics and/or copper metallizations. In addition, many of these alkaline cleaning agents contain organic solvents that exhibit low product stability, particularly in the higher pH ranges and at higher process temperatures.

Therefore, there is a need for microelectronics cleaning preparations suitable for final cleaning operations, for preparations that clean effectively and are applicable for removing photoprotective layers, cleaning residues from plasma processes that generate organic, organometallic and inorganic materials, and cleaning residues from planarization process steps, such as chemical mechanical polishing and the like. This invention relates to compositions that are effective for removing the photoprotective layer, preparing/cleaning semiconductor surfaces and structures, with good compatibility with modern bridging materials, such as low-K and high-K dielectrics, and copper metallizations.

Ammonia (NH3) and bases derived from ammonia such as ammonium hydroxide and other salts (NH4X, X = OH, carbonate etc.) have been found to be able to dissolve/corrode metals such as copper through complexation. Thus, they are a poor choice for use in semiconductor cleaning formulations when compatibility with porous low-Ki dielectrics and high-Ki copper metallizations is required. These compounds can generate ammonia through an equilibrium process. Ammonia can form a complex with metals, such as copper, leading to corrosion/dissolution of the metal, as shown in the following equations.

Thus, ammonium hydroxide and ammonium salts can provide the nucleophilic and metal-chelating ammonia (NH3) necessary via the equilibrium process described in Equation 1, especially when other bases, such as amines and alkanolamines, are added. In the presence of oxygen, metals such as copper can dissolve/corrode via complexation with ammonia, as described by Equation 2. This complexation can further shift the equilibrium (Equation 1) to the right, yielding more ammonia, leading to even more dissolution/corrosion of the metal.

Typically, sensitive low-K dielectrics degrade significantly under strongly alkaline conditions. Ammonia and ammonia-derived bases also show poor compatibility with sensitive dielectrics, such as hydrogen silsesquioxane (HSQ) and methyl silsesquioxane (MSQ). Again, they can generate ammonia and/or other nucleophiles and thus lead to reaction/degradation of sensitive dielectrics.

Cleaning formulations with strong alkaline bases, which do not generate ammonia and contain non-nucleophilic, positively charged counter-ions (such as tetraalkylammonium) in amide solvents with stem hindrance, have been found to show greatly improved compatibility with sensitive, porous low-K and high-K dielectrics and towards metallization with copper. Preferred solvent matrices are resistant to strongly alkaline conditions, due to steric hindrance effects and/or low or no reactivity towards nucleophilic reactions (relative to nucleophiles such as hydroxyl ion). Better compatibility with dielectrics is partly achieved due to the absence of undesirable nucleophiles in the preparations. Good compatibility towards copper metallization is achieved by the selective use of some copper-compatible, sterically hindered amide solvents. These components can be formulated into semi-aqueous to practically non-aqueous (organic solvent based) cleaning solutions, or thick suspensions.

The novel final cleaning composition of this invention contains one or more suitable non-ammonia forming strong bases, containing non-nucleophilic, positively charged counterions and one or more suitable stem hindered amide solvents, stable under strongly alkaline conditions. Among suitable non-ammonia-forming strong bases containing non-nucleophilic, positively charged counterions for use in the cleaning compositions of this invention may be mentioned the tetraalkylammonium hydroxides of the formula:

where each R is independently, substituted or unsubstituted alkyl, preferably alkyl or hydroxyalkyl with 1 to 22, more preferably 1 to 6 carbon atoms (R*H); and X = OH or a suitable salt anion, such as carbonate and the like; and p and q are equal, integers from 1 to 3. Suitable strong bases are also KOH and NaOH. Cleaning preparations containing strong bases that do not generate ammonia, but contain non-nucleophilic, positively charged counter-ions, show significantly better compatibility with low-Ki metallization dielectrics with copper. Ammonia-free tetraalkylammonium hydroxides (TAAH) are very strong bases, yet surprisingly they have been found to provide improved low-K compatibility compared to ammonium hydroxide cleaners. Particularly preferred are tetramethylammonium hydroxide, tetrabutylammonium hydroxide, choline hydroxide and tetramethylammonium carbonate. Although previous attempts to control or inhibit metal corrosion have involved careful control of pH and/or the use of corrosion inhibitor compounds, such as benzotriazole (BT), at relatively low concentrations <2 wt%, it has been found that an unexpected, significant improvement in the control of metallic copper corrosion can be provided with the cleaning compositions of this invention, when one or more hindered amide solvents are used. Any suitable hindered amide solvent can be used in the cleaning compositions of this invention. As such sterically hindered amide solvents, sterically hindered acyclic and sterically hindered cyclic amides with the formula:

where n is an integer from 1 to 22, preferably 1 to 6; and R 1 , R 2 , R 3 , R 4 , R 5 , Re , R 7 and R 5 are each independently selected from H, alkyl (substituted or unsubstituted), preferably alkyl of 1 to 6 carbon atoms, and aryl (substituted or unsubstituted), preferably aryl of 3 to 14 carbon atoms, provided that at least one between R 2 , R 2 and R 3 and at least one between R 4 | R5, R6, R7 and R are hydrogen.

Some suitable examples of these stem-hindered amide acyclic solvents are, for example, acetamide, dimethylformamide (DMF), N,N'-dimethylacetamide (DMAc), benzamide and the like. Some suitable examples of stem hindered cyclic amides are, for example, N-methyl-2-pyrrolidinone (NMP), 1,5-dimethyl-2-pyrrolidinone, 1,3-dimethyl-2-piperidone, 1-(2-hydroxyethyl) 2-pyrrolidinone, 1,5-dimethyl 2-piperidone and the like.

The cleaning compositions of this invention containing strong bases that do not produce ammonia can be formulated into aqueous, semi-aqueous and organic solvent based compositions. Strong bases, which do not produce ammonia, and which contain non-nucleophilic, positively charged counter-ions, can be used with stem-hindered amide solvents, alone or in combination with other stable solvents, preferably with one or more polar organic solvents resistant to strong bases, which do not contain unhindered nucleophiles, such as dimethylsulfoxide (DMSO), sulfolane (SFL), dimethylpiperidone, diethanolamine, triethanolamine, 2-(methylamino)ethanol, 3-(dimethylamino)-1,2-propanediol and the like. The cleaning composition may also optionally contain organic or inorganic acids, preferably weak organic or inorganic acids, hindered amines, hindered alkanolamines and hindered hydroxylamines and other corrosion inhibitors, such as benzotriazole, catechol, glycerin, ethylene glycol and the like. Cleansing compositions may also contain any suitable surfactant, such as, for example, dimethylhexinol (Surfynol-61), ethoxylated tetramethyldecynediol (Syrfinol-465), polytetrafluoroethylene cetoxypropyl betaine (Zonyl FSK), (Zonyl FSH) and the like. Thus, a wide range of operating/operable pH and temperatures can be used for effective removal and cleaning of photoprotective layers, etching/burning residues after plasma treatment, easily absorbent auxiliary materials and anti-reflective coatings (ARC). It has also been found that some of these types of formulations are particularly effective for cleaning very demanding samples that contain tantalum in their structure, such as tantalum (Ta) or tantalum-nitride barrier layers, and tantalum oxides.

Any metal ion-free silicate can be used in the compositions of this invention. These preferred silicates are quaternary ammonium silicates, such as tetraalkylammonium silicate (including alkyl containing hydroxy and alkoxy groups, typically with from 1 to 4 carbon atoms in the alkyl or alkoxy group). The most preferred silicate component without metal ions is tetramethylammonium silicate. Other sources of metal ion-free silicates suitable for this invention can be generated in situ by dissolving any one or more of the following materials in a strongly alkaline cleaning agent. Suitable metal ion-free materials useful for generating the silicate in the cleaning agent are solid silicon wafers, silicic acid, colloidal silica, fumed silica, or any other suitable form of silicon or silica. Metal silicates, such as sodium metasilicate, can be used, but are not recommended due to adverse effects and contamination of integrated circuits with metals. Such silicates can be present in this preparation in a content of about 0 to 10 wt%, preferably in a content of about 0.1 to about 5 wt%.

The compositions of the present invention may also be formulated with suitable metal chelating agents to increase the capacity of the formulation to retain the metal in solution and to improve the dissolution of metal residues on the substrate wafer. The chelating agent is usually present in these preparations in a content of about 0 to 5% by weight, preferably in a content of about 0.1 to 2% by weight. Typical examples of chelating agents useful for this purpose are the following organic acids, their isomers and salts: (ethylenedinitrilo)tetraacetic acid (EDTA), butylenediaminetetraacetic acid, (1,2-cyclohexylenedinitrilo)tetraacetic acid (CyDTA), diethylenetriaminepentaacetic acid (DETPA), ethylenediaminetetrapropionic acid, (hydroxyethyl)ethylenediaminetetraacetic acid (HEDTA), N,N,N',N'-ethylenediaminetetra(methylenephosphonic) acid (EDTMP), triethylenetetraminehexaacetic acid (TTHA), 1,3-diamino-2-hydroxyproane-N,N,N',N'-tetraacetic acid (DHPTA), methyliminodiacetic acid, propylenediaminetetraacetic acid, nitrolotyracetic acid (NTA), citric acid, tartaric acid, gluconic acid, saccharin acid, glycerin acid, oxalic acid, phthalic acid, maleic acid, mandelic acid, malic acid, lactic acid, salicylic acid, catechol, gallic acid, propyl gallate, pyrogallol, 8-hydroxyquinoline and cysteine. Preferred chelating agents are aminocarboxylic acids, such as EDTA, CyDTA and EDTMP.

The cleaning compositions may also optionally contain fluoride compounds in the cleaning composition, such as, for example, tetramethylammonium fluoride, tetrabutylammonium fluoride, and ammonium fluoride. Other suitable fluorides are, for example, fluoroborates, tetrabutylammonium fluoroborates, aluminum hexafluorides, antimony fluoride, and the like. Fluoride components are present in a content of from 0 to 10% by mass, preferably from about 0.1 to 5% by mass.

The cleaning compositions of this invention typically contain from about 0.05 to about 30% by weight of a strong base that does not produce ammonia; from about 5 to about 99.95 wt% of the sterically hindered amide solvent component; from about 0 to about 95% by weight of water or other organic co-solvent; from about 0 to 40% by weight of stem hindered amines or alkanolamines; about 0 to 40% by mass of organic or inorganic acids; about 0 to 40% by weight of compounds that are corrosion inhibitors, such as benzotriazole, catechol, glycerin, ethylene glycol and the like; from about 0 to 5 wt% surfactant; from about 0 to 10 wt% silicate without metal ions; from about 0 to 5% by weight of a metal chelating agent; and from about 0 to 10% by weight of a fluoride compound.

Examples of these types of formulations are given in Table 1 below.

Copper etch rates for Preparations D, E, F, G and H from Table 1 are shown through the etch rate data in Tables 2 and 3 that follow. The etching rate was determined using the following test procedure.

Pieces of copper foil, measuring approximately 13x50 mm, are used. The thickness of the piece of foil is measured. After cleaning the foil pieces with 2-propanol, distilled water and acetone, the foil pieces are dried in an oven. The cleaned, dried pieces of foil are then placed in covered jars with preheated cleaning preparations from this invention, then placed in a vacuum oven, at the indicated temperature, for 2 to 4 hours. After treatment, removal from the dryer and from the jars, the cleaned foils are washed abundantly with distilled water and dried in the dryer for about 1 hour, then they are left to cool to room temperature, and the rate of etching is determined based on the loss of mass or change in mass.

The results are given in Tables 2 and 3.

The cleaning capacity of the preparations of this invention is illustrated by the following tests in which the microelectronic structure [consisting of a plate with the following structure: PR/ARC/CDO/SiN/Cu Dual Damascene (pit after etching), where PR is photoprotective and ARC = anti-reflective coating] is immersed in cleaning solutions of the indicated temperatures and times, then washed with water, dried, and the cleaning effect is determined by SEM. These results are given in Table 4.

By means of the foregoing description of the present invention, those skilled in the art understand that modifications may be made to the present invention without departing from its spirit and scope. Therefore, it is intended that the scope of the present invention not be limited to the specific embodiments illustrated and shown.

Claims (46)

1. A cleaning preparation, for cleaning residues from microelectronic substrates, characterized in that said cleaning preparation contains: from about 0.05 to 30 wt% of one or more strong bases that do not produce ammonia, and which contain non-nucleophilic, positively charged counterions; from about 5 to about 99.5 wt% of one or more stem hindered amide solvents; from about 0 to about 95% by weight of water or other organic co-solvent; from about 0 to about 40% by weight of a stem hindered amine or alkanolamine; from about 0 to 40 wt% organic or inorganic acid; from about 0 to 40% by weight of other compounds which are metal corrosion inhibitors; from about 0 to 5 wt% surfactant; from about 0 to 10% by weight of a metal ion-free silicate compound; from about 0 to 5% by weight of a metal chelating agent; and from about 0 to 10% by weight of a fluoride compound. 2. The cleaning preparation according to Claim 1, characterized in that the strong base that does not produce ammonia is represented by tetraalkylammonium hydroxide or its salt. 3. The cleaning preparation according to Claim 2, characterized in that tetraalkylammonium hydroxide or its salt is a compound of the formula: wherein each R is a substituted or unsubstituted alkyl group and X is OH or a salt anion; p and q are equal, and represent an integer from 1 to 3. 4. The cleaning preparation according to Claim 3, characterized in that R is an alkyl group containing from 1 to 22 carbon atoms, and X is OH or carbonate. 5. The cleaning preparation according to Claim 4, characterized in that R is an alkyl group with from 1 to 6 carbon atoms. 6. The cleaning preparation according to Claim 1, characterized in that the hindered amide solvent is a compound selected from those having the formula: wherein n is a number from 1 to 22, and Ri, R2, R3, R<t, R5, Re, R7, and Ra are each independently selected from the group consisting of H, alkyl, and aryl, provided that at least one of R1, R2, and R3, and at least one of R4, R5, Re, R7, and Rhenium are hydrogen. 7. The cleaning preparation according to Claim 2, characterized in that the hindered amide solvent is a compound selected from those having the formula: wherein n is a number from 1 to 22, and R 1 , R 2 , R 3 , R 4 , R 5 , R e , R 7 , and R s are each independently selected from the group consisting of H, alkyl, and aryl, provided that at least one of R 1 , R 2 , and R 3 , and at least one of R 4 , R 5 , R 7 , and R 7 are hydrogen. 8. The cleaning preparation according to Claim 3, characterized in that the hindered amide solvent is a compound selected from those having the formula: wherein n is a number from 1 to 22, and R1, R2, R3, R4, R5, Re, R7, and Rs are each independently selected from the group consisting of H, alkyl, and aryl, provided that at least one of R, R2, and R3, and at least one of R4, R5, R6, R7, and Rs are hydrogen. 9. The cleaning preparation according to Claim 4, characterized in that the hindered amide solvent is a compound selected from those having the formula: wherein n is a number from 1 to 22 and R1(R2, R3, R4, R5)Re, R7 and R5 are each independently selected from the group consisting of H, alkyl and aryl, provided that at least one of R, R2 and R3 and at least one of R4, R5, Re, R7 and Rs are hydrogen. 10. The cleaning preparation according to Claim 5, characterized in that the sterically hindered amide solvent is a compound selected from those having the formula: wherein n is a number from 1 to 22, and R-i, R2, R3, R4, R5, R6, R7, and Rs are each independently selected from the group consisting of H, alkyl, and aryl, provided that at least one of R-i, R2, and R3, and at least one of R4, R5, Re, R7, and Rs are hydrogen. 11. The method according to Claim 10, characterized in that in the definition of the group R1 to Ra the alkyl group has 1 to 6 carbon atoms, and the aryl group has 3 to 14 carbon atoms. 12. The cleaning preparation according to Claim 1, characterized in that the sterically hindered amide solvent is selected from the group consisting of acetamide, dimethylformamide (DMF), N,N'-dimethylacetamide (DMAc), N-methyl-2-pyrrolidinone (NMP), 1,5-dimethyl-2-pyrrolidinone, 1,3-dimethyl-2-piperidone, 1-(2-hydroxyethyl)2-pyrrolidinone and 1,5-dimethyl 2-piperidone. 13. The cleaning preparation according to Claim 2, characterized in that the sterically hindered amide solvent is selected from the group consisting of acetamide, dimethylformamide (DMF), N.N'-dimethylacetamide (DMAc), N-methyl-2-pyrrolidinone (NMP), 1,5-dimethyl-2-pyrrolidinone, 1,3-dimethyl-2-piperidone, 1-(2-hydroxyethyl) 2-pyrrolidinone and 1,5-dimethyl 2-piperidone. 14. The cleaning preparation according to Claim 3, characterized in that the sterically hindered amide solvent is selected from the group consisting of acetamide, dimethylformamide (DMF), N,N'-dimethylacetamide (DMAc), N-methyl-2-pyrrolidinone (NMP), 1,5-dimethyl-2-pyrrolidinone, 1,3-dimethyl-2-piperidone, 1-(2-hydroxyethyl) 2-pyrrolidinone and 1,5-dimethyl 2-piperidone. 15. The cleaning preparation according to Claim 4, characterized in that the hindered amide solvent is selected from the group consisting of acetamide, dimethylformamide (DMF), N,N'-dimethylacetamide (DMAc), N-methyl-2-pyrrolidinone (NMP), 1,5-dimethyl-2-pyrrolidinone, 1,3-dimethyl-2-piperidone, 1-(2-hydroxyethyl)2-pyrrolidinone and 1,5-dimethyl 2-piperidone. 16. The cleaning preparation according to Claim 5, characterized in that the hindered amide solvent is selected from the group consisting of acetamide, dimethylformamide (DMF), N,N'-dimethylacetamide (DMAc), N-methyl-2-pyrrolidinone (NMP), 1,5-dimethyl-2-pyrrolidinone, 1,3-dimethyl-2-piperidone, 1-(2-hydroxyethyl)2-pyrrolidinone and 1,5-dimethyl 2-piperidone. 17. Cleaning preparation according to Claim 1, characterized in that it contains water or at least one other organic co-solvent selected from the group consisting of dimethylsulfoxide, sulfolane, diethanolamine, triethanolamine, 2-(methylamino)ethanol and 3-(diethylamino)-1,2-propanediol. 18. Cleaning preparation according to Claim 6, characterized in that it contains water or at least one other organic co-solvent selected from the group consisting of dimethylsulfoxide, sulfolane, diethanolamine, triethanolamine, 2-(methylamino)ethanol and 3-(diethylamino)-1,2-propanediol. 19. The cleaning preparation according to Claim 11, characterized in that it contains water or at least one other organic co-solvent selected from the group consisting of dimethylsulfoxide, sulfolane, diethanolamine, triethanolamine, 2-(methylamino)ethanol and 3-(diethylamino)-1,2-propanediol. 20. Cleaning preparation according to Claim 16, characterized in that it contains water or at least one other organic co-solvent selected from the group consisting of dimethylsulfoxide, sulfolane, diethanolamine, triethanolamine, 2-(methylamino)ethanol and 3-(diethylamino)-1,2-propanediol. 21. Cleaning preparation according to Claim 1, characterized in that it contains tetramethylammonium hydroxide, dimethylpiperidone, triethanolamine, trans-1,2-cyclohexanediaminetetraacetic acid and water. 22. Cleaning preparation according to Claim 1, characterized in that it contains tetramethylammonium hydroxide, dimethylpiperidone and water. 23. Cleaning preparation according to Claim 1, characterized in that it contains tetramethylammonium hydroxide, dimethylpiperidone, triethanolamine, ethylenediamine tetra(methylenephosphonic acid) and water. 24. A method for cleaning a microelectronic substrate having at least one porous dielectric, low dielectric, dielectric high-K metallization with copper, characterized in that the method consists in bringing this substrate into contact with a cleaning preparation for a long enough time to clean the substrate, wherein the cleaning solution contains: from about 0.05 to 30 mass% of one or more strong bases that do not produce ammonia, and which contain non-nucleophilic, positively charged counter-ions; from about 5 to about 99.5% by weight of one or more stem hindered amide solvents; from about 0 to about 95% by weight of water or other organic co-solvent; from about 0 to about 40% by weight of a stem hindered amine or alkanolamine; from about 0 to 40 wt% organic or inorganic acid; from about 0 to 40% by weight of other corrosion inhibitor compounds; from about 0 to 5 wt% surfactant; from about 0 to 10% by weight of a metal ion-free silicate compound; from about 0 to 5% by weight of a metal chelating agent; and from about 0 to 10% by weight of a fluoride compound. 25. The method according to claim 24, characterized in that the strong base that does not produce ammonia is tetraalkylammonium hydroxide or its salt. 26. The method according to Claim 25, characterized in that the tetraalkylammonium hydroxide or its salt is a compound of the formula: [(R)4N+]p[Xr wherein each R is a substituted or unsubstituted alkyl group and X is OH or a salt anion; p and q are equal and represent an integer from 1 to 3. 27. The method according to Claim 26, characterized in that R is an alkyl group containing from 1 to 22 carbon atoms, and X is OH or carbonate. 28. The method according to Claim 27, characterized in that R is an alkyl group with from 1 to 6 carbon atoms. 29. The method according to Claim 24, characterized in that the sterically hindered amide solvent is a compound selected from those having the formula: wherein n is a number from 1 to 22, and R 2 , R 3 , R 4 , R 5 , R e , R 7 and R s , each independently, are selected from the group consisting of H, alkyl and aryl, provided that at least one of R 1 , R 2 and R 3 and at least one of R 4 , R 5 , Re , R 7 and R s is hydrogen. 30. The method according to Claim 25, characterized in that the hindered amide solvent is a compound selected from those having the formula: wherein n is a number from 1 to 22, and R 1 , R 2 , R 3 , R 1 , R 5 , R 7 , and R 5 , each independently, are selected from the group consisting of H, alkyl, and aryl, provided that at least one of R 1 , R 2 , and R 3 , and at least one of R 4 , R 5 , R 6 , R 7 , and R 7 are hydrogen. 31. The method according to Claim 26, characterized in that the hindered amide solvent is a compound selected from those having the formula: wherein n is a number from 1 to 22 and R1, R2, R3, R4, R5, Re, R7 and R5 are each independently selected from the group consisting of H, alkyl and aryl, provided that at least one of R1, R2 and R3 and at least one of R4, R5, R6, R7 and R8 is not hydrogen. 32. The method according to Claim 27, characterized in that the hindered amide solvent is a compound selected from those having the formula: wherein n is a number from 1 to 22, and R 1 , R 2 , R 3 , R 4 , R 5 , Re , R 7 and R s are each independently selected from the group consisting of H, alkyl and aryl, provided that at least one of R 1 , R 2 and R 3 and at least one of R 4 , R 5 , Re , R 7 and R s is hydrogen. 33. The method according to Claim 28, characterized in that the sterically hindered amide solvent is a compound selected from those having the formula: wherein n is a number from 1 to 22, and R1, R2, R3, R4, R5, Re, R7, and Rs, each independently, are selected from the group consisting of H, alkyl, and aryl, provided that at least one of R1, R2, and R3, and at least one of R4, R5, R6, R7, and Rs are hydrogen. 34. The method according to Claim 33, characterized in that in the definition of the Rido group, the alkyl group has 1 to 6 carbon atoms, and the aryl group has 3 to 14 carbon atoms. 35. The method according to Claim 24, characterized in that the sterically hindered amide solvent is selected from the group consisting of acetamide, dimethylformamide (DMF), N,N'-dimethylacetamide (DMAc), N-methyl-2-pyrrolidinone (NMP), 1,5-dimethyl-2-pyrrolidinone, 1,3-dimethyl-2-piperidone, 1-(2-hydroxyethyl) 2-pyrrolidinone and 1,5-dimethyl 2-piperidone. 36. The method according to Claim 25, characterized in that the sterically hindered amide solvent is selected from the group consisting of acetamide, dimethylformamide (DMF), N,N'-dimethylacetamide (DMAc), N-methyl-2-pyrrolidinone (NMP), 1,5-dimethyl-2-pyrrolidinone, 1,3-dimethyl-2-piperidone, 1-(2-hydroxyethyl) 2-pyrrolidinone and 1,5-dimethyl 2-piperidone. 37. The method according to Claim 26, characterized in that the hindered amide solvent is selected from the group consisting of acetamide, dimethylformamide (DMF), N,N'-dimethylacetamide (DMAc), N-methyl-2-pyrrolidinone (NMP), 1,5-dimethyl-2-pyrrolidinone, 1,3-dimethyl-2-piperidone, 1-(2-hydroxyethyl)2-pyrrolidinone and 1,5-dimethyl 2-piperidone. 38. The method according to Claim 27, characterized in that the hindered amide solvent is selected from the group consisting of acetamide, dimethylformamide (DMF), N,N'-dimethylacetamide (DMAc), N-methyl-2-pyrrolidinone (NMP), 1,5-dimethyl-2-pyrrolidinone, 1,3-dimethyl-2-piperidone, 1-(2-hydroxyethyl)2-pyrrolidinone and 1,5-dimethyl 2-piperidone. 39. The method according to Claim 28, characterized in that the hindered amide solvent is selected from the group consisting of acetamide, dimethylformamide (DMF), N,N'-dimethylacetamide (DMAc), N-methyl-2-pyrrolidinone (NMP), 1,5-dimethyl-2-pyrrolidinone, 1,3-dimethyl-2-piperidone, 1-(2-hydroxyethyl) 2-pyrrolidinone and 1,5-dimethyl 2-piperidone. 40. The method according to Claim 24, characterized in that the cleaning preparation contains water or at least one other co-solvent selected from the group consisting of dimethylsulfoxide, sulfolane, diethanolamine, triethanolamine, 2-(methylamino)ethanol and 3-(diethylamino)-1,2-propanediol. 41. The method according to Claim 28, characterized in that the cleaning preparation contains water or at least one other co-solvent selected from the group consisting of dimethylsulfoxide, sulfolane, diethanolamine, triethanolamine, 2-(methylamino)ethanol and 3-(diethylamino)-1,2-propanediol. 42. The method according to Claim 34, characterized in that the cleaning preparation contains water or at least one other co-solvent selected from the group consisting of dimethylsulfoxide, sulfolane, diethanolamine, triethanolamine, 2-(methylamino)ethanol and 3-(diethylamino)-1,2-propanediol. 43. The method according to Claim 39, characterized in that the cleaning preparation contains water or at least one other co-solvent selected from the group consisting of dimethylsulfoxide, sulfolane, diethanolamine, triethanolamine, 2-(methylamino)ethanol and 3-(diethylamino)-1,2-propanediol. 44. The method according to Claim 24, characterized in that the cleaning preparation contains tetramethylammonium hydroxide, dimethylpiperidone, triethanolamine, trans-1,2-cyclohexanediaminetetraacetic acid and water. 45. The method according to Claim 24, characterized in that the cleaning preparation contains tetramethylammonium hydroxide, dimethylpiperidone and water. 46. The method according to Claim 24, characterized in that the cleaning preparation contains tetramethylammonium hydroxide, dimethylpiperidone, triethanolamine, ethylenediamine tetra(methylenephosphonic acid) and water.