KR970007328B1 - Cleaning agent containing nucleophilic amine compound provided with reduction and oxidation potential - Google Patents

Abstract

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Description

Corrosion and Corrosion Residue Removal Compositions and Removal Methods

Figure 1 shows the corroded wafer residue after removing the resist from the plasma corroded silicon oxide dielectric layer with the use of plasma ashing.

FIG. 2 shows the results of the analysis using ion mass spectroscopy (LIMA) of the residues shown in FIG. 1.

Figures 3a and 3b show the corrosion present on a resist after plasma resist removal by plasma ashing using the cleaning composition of the present invention (Figure 3a) and the stripping composition as described in US Pat. No. 4,403,029 (Figure 3b). Results of comparative tests on silicon oxide dielectric layers containing residues are shown.

4A and 4B show corrosion residues after removal of the resist from plasma resisting by using the cleaning composition of the present invention (FIG. 4A) and the stripping composition as described in US Pat. No. 4,770,713 (FIG. 4B). The result of the comparative test on the silicon dielectric layer is shown.

FIG. 5A shows a microcircuit pattern of poly-silicon on silicon oxide containing corrosion residues remaining on the support after platmamas corrosion.

Figure 5b shows the same microcircuit pattern of the wash section with the composition of the present invention.

Figure 6a shows the residue remaining on the metal support after removing the photoresist from the support by plasma ashing.

Figure 6b shows the same support after washing with the composition of the present invention.

Figures 7a-7d show pores on a silicon oxide dielectric layer using the cleaning composition of the present invention (Figures 7a and 7b) and N-methyl-2-pyrrolidone solvent / alkanolamine based stripper (Figures 7c and 7d). The result of the comparative test is shown.

8A shows residue left on the wafer after corrosion and removal of the photoresist therefrom. 8B shows the same wafer after washing with the composition of the present invention. All residue on the wafer was removed.

9 illustrates the results of Example 11 below, comparing wash compositions A, C, and G.

The present invention relates to resists and corrosion residue removal compositions composed of at least one nucleophilic amine compound having a reduction and oxidation potential, at least one organic solvent miscible with the nucleophilic amine, water and optionally one or more chelating agents. . This solution is useful for removing resists and corrosion residues from microcircuits during processing.

The present invention is a cleaning composition for removing corrosion residues and a method of use, which is CIP of US Patent Application Serial No. 610,044, filed November 5, 1990 entitled Stripping Compositions Containing Hydroxylamine and Alkanolamine. CIP, US Serial Number 91l, 102, filed on July 9, 1992.

During processing of the microcircuits, accurate positioning of a number of suitably doped regions on the slice of semiconductor is required, followed by positioning of one or more interconnect patterns on the semiconductor. Yang-type resists have been widely used as masking materials that delineate patterns on supports so that the patterns can be sequentially corroded or otherwise formed in the support. The final step in the support preparation then involves the removal of unexposed resist material and any corrosion residues from the support.

However, increasingly using plasma corrosion, reactive ion corrosion or ion milling, the following solvents: halogenated hydrocarbons such as methylene chloride or tetrachloroethylene; Amines and derivatives thereof such as dimethinformamide, dimethylacetamide, pyrrolidone, diethanolamine, and triethanolamine; Glycol ethers such as ethylene glycol monoethyl ether, 2-butoxy ethanol, and 2- (butoxyethoxy) ethanol; And a stripping agent previously used for such or similar purposes, including one or more of alkylsulfones such as dimethylsulfone, to form a pattern in the support that makes it virtually impossible to remove the resist mask.

In addition, organometallic by-product compounds may be formed on the sidewalls of the support material during the corrosion treatment. In addition, the aforementioned solvents are not effective for removing the organometallic polymer. A technique useful for photoresist removal recently developed is plasma oxidation, also known as plasma ashing. However, this method is effective for removing photoresist, but not for removing organometallic polymer formed on the sidewall of the support during the corrosion process.

In addition, polyimide is increasingly used in microelectronics as processing aids, passivants, and mid-level insulators. The use of polyimides as processing aids includes the application of polyimides as ion implantation masks and as photoresists that are planarization layers in multi-level photoresist structures.

In this application, the polymer is applied to a wafer or support and subsequently cured or patterned by a suitable method and removed after use. Once the polyimide has been subjected to stringent curing operations, many conventional strippers are not effective enough to remove the polyimide layer. Removal of the polyimide is usually carried out by heating the support in hydrazine or in an oxygen plasma.

Thus, a composition suitable as a stripping resist for quickly and completely removing the resist will provide substantial advantages over conventional strippers. In addition, compositions that can remove both resists and organometallic by-products will provide even greater advantages.

Obviously, if the corrosion residues are not completely removed from the support, the residues may interfere with subsequent processes of moistening the support.

In particular, a submicron process technology is used to form the wafer to completely remove the resist material, and a cleaning technique for removing the corrosion residue following the resist removal is required. Cleaning solutions to remove all types of residues resulting from plasma corrosion of various types of metals, such as aluminum, aluminum / silicon / copper, titanium, titanium nitride, titanium / tungsten, tungsten, silicon oxide, polysilicon crystals, etc. The need creates a need for more effective cleaning chemicals in the treatment area.

More particularly, during the processing of the microcircuits, the support surface may be aluminum, titanium, silicon oxide or polysilicon and the pattern is contoured thereon by chemical corrosion. Increasingly, plasma erosion, reactive ion erosion or ion milling is used, and the erosion method produces unwanted byproducts from the interaction of plasma gases, reacted species and photoresists. The byproduct composition generally consists of a corroded support, an underlying support, a photoresist and a corrosive gas. The formation of these by-products is influenced by the corrosion equipment used, the treatment conditions and the type of support. Generally these by-products are sidewall polymers, bales. By conventional solvents such as picket fence, rabbit ears or goat's horn and used for oxygen plasma or commonly used for resist removal such as N-methyl-2-pyrrolidone, diethylene glycol monobutyl-ether, dimethylacetamide and the like It cannot be removed completely. It is important to remove all corrosion residues and the like to provide a wafer with sufficient density for sequential use of the wafer in microcircuits.

Examples of alkali / solvent mixtures that are known to be used in stripping applications but not necessarily cleaning agents but useful as photoresist strippers are dimethylacetamide or dimethylformamide and alkanols as described in US Pat. Nos. 4,770,713 and 4,403,029. Amines; 2-pyrrolidone, dialkylsulfones and alkanolamines as described in US Pat. Nos. 4,428,871, 4,401,747 and 4,395,479; And 2-pyrrolidone and tetramethylammonium hydroxide as described in US Pat. No. 4,744,834. However, only the above stripping composition is a simple microcircuit involving a single layer of metal when the metal structure mainly contains Al-Si or Al-Si-Cu and the sidewall polymer residue contains an organometallic compound with only aluminum. It has proved successful only in sidewall polymer cleaning from contact openings and metal corrosion from manufacturing.

The washing mechanism involving the materials is P.L. pai, C.H. By Ting, W.M.Lee and R. Kuroda, in 1989, K.T.I. As submitted to the meeting, EKC Technology Inc. And Intel Corp. Due to the corrosive nature of the stripper as described above, the sidewall polymer is removed by attacking the organoaluminum compound or the metal surface itself and lifting off the sidewall polymer residue. In addition to the use of stripping compositions, mechanical scrubbing such as ultrasonic vibrations is required to achieve complete removal of the sidewall polymer.

The most recent submicron treatment technology used in industries involving multi-level metal and multi-level interconnect processes usually incorporates metal materials including TiN, TiW, Ti, TiSi, W, WSi, and the like.

The use of these materials to incomplete cleaning when using existing commercially available stripping and cleaning products, whether formed intentionally or unintentionally, results in the production of new organometallic material byproducts during plasma corrosion. The findings were described at the SPIE Symposium on Microlithography in 1991 by John W. Coburn in the publication entitled Plasma Corrosion and Reactive Ion Corrosion. In particular, it was found that the residue remaining on the support surface after removal of the resist by plasma ashing turns into a corresponding oxide, such as TiO ₂ , which is chemically inert to mild alkaline strippers in organometallics. The effect of poor cleaning results in low device yield, low device reliability, and low device performance.

Thus, conventional stripping compositions are not effective at removing sidewall organometallics and other metal oxide residues present using current techniques for resist removal. Even plasma ashing, which has been developed to be effective for removing photoresist, is not effective at removing sidewall organometallic polymers and some other metal oxide residues formed during the corrosion process.

Accordingly, a primary object of the present invention is at least one nucleophilic amine compound having oxidation and reduction potential, at least one solvent miscible with the nucleophilic amine compound; Resist and corrosion residue removal compositions composed of water and optionally one or more chelating agents; And a method of using the composition to completely remove the resist and wash the microcircuit support.

Additional primary objects of the present invention are at least one nucleophilic amine compound having oxidation and reduction potentials, at least one solvent miscible with the nucleophilic amine compound; It is to provide a composition consisting of water and optionally one or more chelating agents to provide a resist and corrosion residue removal composition with long term stability.

A further primary object of the present invention is to provide a resist and corrosion residue removal composition comprising at least one nucleophilic amine compound having a reduction and oxidation potential, at least one solvent miscible with the nucleophilic amine compound, and water. At this time, the nucleophilic amine and the organic solvent are kept separately and can be disposed of after use because they have a short active life cycle in combination just before use. Alternatively, the composition can be reactivated once it is formed by combining the same components as above and combining the chelating agent with it.

It is a further primary object of the present invention to provide a composition for removing residues formed during corrosion and resist removal processes from a support without obstructing subsequent operations or processing steps involving the support or adversely damaging the surface of the support.

The present invention provides at least one nucleophilic amine compound having oxidation and reduction potential, at least one organic solvent miscible with the nucleophilic amine compound; A resist and corrosion residue removal composition consisting of water and optionally one or more chelating agents. Water may be added to the composition by itself or as a carrier for the nucleophilic amine compound, ie the nucleophilic amine is present in aqueous solution.

Related application U.S. Serial No. 610,044, filed November 5, 1990, corresponding to published European Patent Application No. 485,161A1, is useful for removing resists from a support, which is useful for removing hydroxylamines with alkalolamines that are miscible with hydroxylamines. Made public. Compounds other than hydroxylamine and alkanolamine have also been found useful in resist removal but also in particular in removing corrosion residues from supports. It has been found that nucleophilic amine compounds having oxidation and reduction potentials satisfactorily remove resists and corrosion residues from supports when combined with nucleophilic amine compounds and organic solvents that are miscible with water. The nucleophilic amine compound must have a potential for reduction and oxidation, but the use of the composition does not actually require reduction and oxidation. Examples of nucleophilic amine compounds useful in the present invention include hydroxylamine, hydrazine, certain aforementioned amines, and their derivatives as further described below. The organic solvent need not be an amine, but the presence of an amine solvent is preferred.

It has also been found that at least two additional surprising advantages are achieved when the chelating agent is present in an aqueous solution comprising at least one nucleophilic amine compound having a reduction and oxidation potential and an organic solvent miscible with the nucleophilic amine compound. That is, (1) the chelating agent retains corrosion residues in the wash solution to aid in cleaning by preventing reattachment of the residue on the support, and (2) the chelating agent acts as a stabilizer to provide long-term effects to the composition. More particularly, the chelator enhances the cleaning ability of the composition by retaining or freezing the corrosion residue in the wash solution after the nucleophilic amine compound has taken up the residue from the support. This action minimizes the reattachment of any residue on the support. Additionally the presence of the chelating agent provides a composition with long term activity and thus a long shelf life. When the chelating agent is not present in the aqueous solution of the nucleophilic amine compound and the organic solvent, the solution has only short term stability, i.e. generally about one week of active life. Therefore, when no chelating agent is present, it is desirable to separately maintain the nucleophilic amine compound and the organic solvent until just before use. After combining the components and using the solution, the remaining solution can be disposed of, or once the activity is reduced, the solution can be reactivated by the addition of a chelating agent. Preferred chelating agents are dihydroxybenzenes and their derivatives as further described below.

In particular, the cleaning composition is useful for removing corrosion residues from supports containing metal elements other than aluminum, such as titanium (Ti), tungsten (W), silicon (Si) and silicon oxide (SiO ₂ ). While the composition of the present invention can remove the resist from the support, the composition of the present invention has been shown to have a surprising ability to cleanly remove organometallic and metal oxide corrosion residues from the support after removal of the corrosion residues, in particular the resist. In the present industry, corrosion residues are extremely difficult to completely remove without damaging the support.

The cleaning compositions of the present invention remove organometallic and metal oxide residues from the support without disrupting or adversely affecting subsequent manufacturing processes or processing steps involving the support, especially during processing of submicron (ie less than 0.8 micron) integrated circuits. Particularly suitable for In addition, the cleaning compositions of the present invention are effective in removing organometallic residues that generate gases disposed on parts of corrosion equipment used in the process. The equipment can be made of polycarbonate, ceramic or aluminum.

In addition, the method of removing the scaffold resist or corrosion residues using the compositions of the present invention is advantageous in that no complicated processing steps and equipment are required. The method of the present invention comprises contacting the composition of the invention as described herein with a support containing the resist or the corrosion residue for a temperature and time sufficient to remove the particular resist or the corrosion residue present.

Analysis of FIG. 2 shows that the residue contains metal oxides and trace amounts of organometallics.

Comparing Figures 3a and 3b, it can be seen that residues remain after use of the stripping compositions described in US Pat. No. 4,403,029, while all organometallic residues are removed using the compositions of the present invention.

As evidence from the comparison of Figures 4a and 4b, the compositions of the present invention were all free of organometallic residues while the remaining compositions were not.

As evidence from the comparison of Figures 5a and 5b, it can be seen that the residue has been removed.

Figure 6b shows the same support after washing with the composition of the present invention.

As shown in Figures 7a and 7b, all organometallic residues were removed using the compositions of the present invention, while as evidence from Figures 7c and 7d, residues remained on the stripper treated support.

The cleaning and stripping compositions of the present invention for removing resist and corrosion residues from a support include at least one nucleophilic amine compound having oxidation and reduction potential in a washing environment, at least one organic solvent miscible with the nucleophilic amine compound, Water and optionally one or more chelating agents. Water may be provided as a composition independently or in combination with a nucleophilic amine compound. For example, the nucleophilic amine compound can be added as a 50% aqueous solution.

In the composition according to the invention, the composition may preferably contain a chelating agent. Chelating agents provide long term stability and activity to the composition. Thus, the composition has the desired commercial properties with long shelf life.

Alternatively, a composition consisting of at least one nucleophilic amine compound, organic solvent and water having a reduction and oxidation potential can be provided. However, since the composition has only a short term effect, it is preferable to keep the nucleophilic amine compound and the organic solvent separately until just before use.

As mentioned above, water may be present with nucleophilic amine compounds. In this case, the nucleophilic amine compound in aqueous solution will remain separated from the organic solvent until just before use. Then combine the ingredients and use the composition as needed. In general, compositions without chelating agents will have an effective lifespan for approximately one week. Any unused portion of the composition can then be simply disposed of or alternatively, a chelating agent can be added to the solution to reactivate the unused portion.

The compositions of the present invention can be used as stripping compositions to remove resists or as cleaning compositions to remove corrosion residues from supports. The corrosion residue removal capability is particularly surprising in view of the difficulties experienced in the art for producing effective corrosion residue removal solutions.

The cleaning composition of the present invention is suitable for removing corrosion residues such as organometallic and metal oxide residues formed on the support, in particular residues formed during the plasma corrosion process. The support may comprise aluminum and non-aluminum metal elements such as titanium, tungsten, silicon and silicon oxide. The extent and type of residue remaining after corrosion is determined by the corrosion equipment used, the process conditions and the support used.

Preferably the cleaning composition comprises at least one nucleophilic amine having a reduction and oxidation potential of about 5% to 50% by weight, at least one organic solvent, optionally about 5, that is miscible with about 10% to 80% by weight of the nucleophilic amine compound. % -30% by weight of at least one chelating agent and the remainder of the composition consisting of water, in particular high purity deionized water.

Compounds suitable for use as nucleophilic amine compounds having oxidation and reduction potentials include certain amines, hydroxylamines, hydrazines and derivatives thereof as listed below. The nucleophilic amine compounds used in the present invention should not actually participate in oxidation or reduction during the washing or stripping process. The nucleophilic oxidizing compounds must have oxidative and reducing power in a washing or stripping environment.

Suitable nucleophilic amine compounds useful in the present invention are compounds having the following general formula or salts thereof:

Wherein R ₁ , R ₂ , R ₃ and R ₄ are the same or different and are hydrogen, a hydroxyl group; Substituted C ₁ -C ₆ straight, branched or cycloalkyl, alkenyl or alkynyl groups; Substituted acyl groups; Linear or branched alkoxy group; Amidyl group; Carboxyl group; Alkoxyalkyl group; Alkylamino group; Alkyl sulfonyl group; Or selected from the group containing sulfonic acid groups; x = 0 when y = 1 or x = 0 or 1 when y = 0; y = 0 when x = 1 or y = 0 or 1 when x = 0; Provided that R ₄ only exists when x = 1. Specific examples of nucleophilic amine compounds are additionally described below.

Hydroxyamines suitable for use as nucleophilic amine compounds with reducing and oxidative transitions are represented by amine compounds having the following general formula or salts of the following compounds.

At this time, R ₁ , R ₂ and R ₃ are independently hydrogen; Hydroxyl group; Optionally substituted C ₁ -C ₆ straight, branched or cycloalkyl, alkenyl or alkynyl groups; Optionally substituted acyl, straight or branched alkoxy group, amidyl group, carboxyl group, alkoxyalkyl group, alkylamino group, alkylsulfonyl group, or sulfonic acid group. Derivatives of these compounds, such as the amides described above, are also suitable for use.

Suitable amines for use as the nucleophilic amine compounds of the present invention can be represented by the following general formulas or salts of the following compounds:

At this time, R ₁ , R ₂ and R ₃ are independently hydrogen; Optionally substituted C ₁ -C ₆ straight, branched or cycloalkyl, alkenyl, or alkynyl groups; Optionally substituted acyl, straight or branched alkoxy group, amidyl group, carboxyl group, alkoxyalkyl group, alkylamino group, alkylsulfonyl group, or sulfonic acid group.

Hydrazines suitable for use as the nucleophilic amine compounds of the present invention can be represented by the following general formulas or salts of the following compounds:

At this time, R ₁ , R ₂ , R ₃ and R ₄ are independently hydrogen; Hydroxyl group; Optionally substituted C ₁ -C ₆ straight, branched or cycloalkyl, alkenyl or alkynyl groups; Optionally substituted acyl group, straight or branched alkoxy group, amidyl group, carboxyl group, alkoxyalkyl group, alkylamino group alkylsulfonyl group, or sulfonic acid group.

Preferred nucleophilic amine compounds with reduction and oxidation potentials are alkoxy substituted amines, hydroxylamines, alkyl or carboxyl substituted hydroxylamines, and alkyl or carboxyl substituted hydrazines. Most preferred compounds are hydroxylamine, N-methylhydroxylamine hydrogen chloride, N, N-diethylhydroxylamine and methylhydrazine.

Organic solvents suitable for use in the present invention are miscible with the nucleophilic amine compound and are preferably water soluble. In addition, the organic solvents useful in the present invention preferably have a relatively high boiling point, such as at least 100 ° C, and a high flash point, such as at least 45 ° C.

Suitable organic solvents include alkinolamines and derivatives thereof. In addition, non-amine solvents such as dimethyl sulfoxide (DMSO) are suitable for use. Preferably the amine solvent is present alone or in combination with another solvent. Previously, it was thought that an alkanolamine solvent should be used. Although alkanolamine solvents are still preferred solvents, other solvents have been found suitable for use when used with at least one nucleophilic amine compound having a reduction and oxidation potential.

Suitable alkanolamines are primary, secondary or tertiary amines and are preferably monoamines, diamines or triamines, and most preferably monoamines. Alkanol groups of amines preferably have 1 to 5 carbon atoms.

Preferred alkanolamines suitable for use in the invention R ₁ and R and ₂ can be _{H, CH 3, CH 3 CH} 2 or CH ₂ CH ₂ OH, R ₃ is CH ₂ CH ₂ OH in the general formula R ₁ R _It can be represented by ₂ -N-CH ₂ CH ₂ -OR ₃ .

Examples of suitable alkanolamines are monoethanolamine, diethanolamine, triethanolamine, tert-butylethanolamine isopropanamine, 2-amino-1-propanol, 3-amino-1-propanol, isobutanolamine, 2- 2-amino-2-ethoxy-ethanol known as amino-2-ethoxypropanol and diglycolamine.

Additional examples of suitable organic solvents for use in the compositions of the present invention include N-methyl-2-pyrrolidone, N, N-dimethylpropanamide, N, N-diethylformamide, ethylene glycol, ethylene glycol alkylethers, Diethylene glycol alkyl ether, triethylene glycol alkyl ether, propylene glycol, propylene glycol alkyl ether, dipropylene glycol alkyl ether, tripropylene glycol alkyl ether, N-substituted pyrrolidone, ethylene diamine and ethylene triamine. Additional polar solvents as known in the art can also be used in the compositions of the present invention.

Preferred chelating agents useful in the compositions of the present invention are hydroxybenzenes or salts of the compounds according to the general formula

Wherein n = 1-4, m = 2-5 and R is independently hydrogen, an optionally substituted C ₁ -C ₆ straight chain, branched or cycloalkyl, alkenyl, or alkylyl group; Optionally substituted acyl group, straight or branched alkoxy group, amidyl group, carboxyl group, alkoxyalkyl group, alkylamino group, alkylsulfonyl group, or sulfonic acid group. Preferred compounds are dihydroxybenzene isomers, and alkylsubstituted dihydroxybenzenes. Most preferred compounds are 1,2-dihydroxybenzene and 1,2-dihydroxy-4-t-butylbenzene.

Additional chelating agents as known in the art can also be used in the compositions of the present invention. For example, chelating agents which are chelating agents free of metal ions, for example thiophenols and derivatives thereof according to the following general formula:

Wherein R ₁ = OH or COOH; Or ethylene diamine tetracarboxylic acid and its ammonium salt of the following general formula can be used.

At this time, R ₁ , R ₂ , R ₃ and R ₄ may be H or NH ₄ . Sodium, potassium, etc. salts are not considered suitable for use based on the known mechanism of ionic contamination in microcircuits caused by washing. As evidence from the above formula, the carboxylic acid may be mono-, di- or tri-substituted rather than tetra-substituted.

Additional suitable chelating agents are general formulas in which R ₁ , R ₂ , R ₃ and R ₄ are preferably short-chain alkyl groups having 1 to 5 carbon atoms, and wherein R ₁ , R ₂ , R ₃ and R ₄ may be the same or different. Alkyl ammonium hydroxide, which can be represented by R ₁ R ₂ R ₃ R ₄ NOH. Preferred alkyl ammonium hydroxide is tetramethylammonium hydroxide.

The present most preferred washing composition of the present invention consists of 35 parts of hydroxylamine, 65 parts of 2-amino-2-ethoxyethanol, and 5 parts of 1,2-dihydroxybenzene based on the total weight of the composition Oxylamine is present in 50% aqueous solution. Other preferred specific embodiments are listed in the examples below.

Examples of supports in which the stripping and cleaning compositions of the present invention remove the photoresist without attacking the support itself include metal supports such as aluminum, titanium / tungsten, aluminum / silicon, aluminum / silicon / copper; And supports such as silicon oxide, silicon nitride, and gallium / arsenic; And plastic supports such as polycarbonate.

The cleaning composition of the present invention is also effective for removing corrosion residues from corrosion equipment used in corrosion supports. Examples of commercially available corrosion equipment include RAM Research, Tecal, Electrotech, Applied Materials, Tokyo Electron, Hitachi, and others.

The method of removing the resist from the support or cleaning the corrosion residue from the support using the composition of the present invention involves contacting the composition of the present invention with a support having the material to be removed at a temperature and for a time sufficient to remove the residue. . The support is immersed in the composition. Immersion times and temperatures are determined based on the specific material removed from the support. Generally, the temperature is in the range of about ambient temperature or room temperature to 100 ° C. and the contact time is about 2 to 60 minutes. A preferred method is to immerse a support sample such as a wafer in a solution of the present invention at a temperature of about 65 ° C. for 30 minutes and then place the support surface in a solvent bath at about 80 ° -85 ° C. for 10 minutes, then rinse the support sample in a water bath. Involves the steps.

Examples illustrating the removal of corrosion residues from the support are listed below. The following examples are provided to further illustrate the invention and do not limit the scope of the invention.

In an embodiment, the support is treated in a conventional known manner prior to treating the support with the compositions of the present invention.

Examples of cleaning compositions according to the invention used in Examples 1-11 below for removal of corrosion residues from supports are listed in Table I below.

TABLE 1

Example 1

Example 1 illustrates the problem of residues remaining on the wafer support after plasma corrosion and ashing. 1 shows the corroded wafer residue present on the corroded support after plasma ashing. In particular, silicon oxide used as the dielectric layer has a corroded pattern for interconnected multilayers according to standard plasma corrosion processes. The photoresist used as the masking material was already removed by oxygen plasma ashing. The residue present on the corroded wafer was analyzed by ion mass spectroscopy (LIMA). The results of the analysis are as shown in FIG. The analysis confirmed that the residue contained metal oxides and trace amounts of organic material.

Example 2

Example 2 illustrates the effect of the cleaning composition of the present invention on wafers as determined by C / V testing. C / V migration measurements are the method used to determine the effect of the chemicals used to clean the wafer. High pressure transfer is mainly caused by mobile ion contamination on the wafer. The contamination will have a detrimental effect on the continuous process step and may result in breakage of the microcircuits.

Test evaluations compare the C / V shifts of the wash compositions of the invention with other conventional photoresist stripping compositions. All wafers used are known to be good silicon oxide supports.

Pyrex beakers were used to heat all chemicals in hot plates up to the manufacturer's suggested operating temperature. Each beaker used was new and not previously used in any chemical process. Individual beakers were used for each product. After immersing the silicon oxide wafer in the described composition, the wafer was rinsed and dried. Table 2 shows the operating conditions and the C / V shift test results. Table 2 is as follows.

TABLE 2

Voice reading means no change in C / V shift.

As described above, the cleaning composition C according to the present invention is known to provide a cleaner surface than any positive photoresist stripper tested.

Example 3

Example 3 sets forth the comparative test results between the composition F and the stripping composition of the present invention as described above, described in US Pat. No. 4,403,029 and sold under the trademark PRS-2000 by J. T. Baker. The results of the comparative test were shown with respect to the openings having a size of 1.2μ in FIGS. 3a and 3b. Each opening was on a silicon oxide dielectric layer corroded using a standard silicon oxide plasma corrosion process. The photoresist was removed from the layer after corrosion by oxygen plasma ashing. The support was then treated by soaking the support in Composition F for 10 minutes at 65 ° C. as described above. Micrographs from the scanning microscope, as shown in FIG. 3A, show that composition F removed all of the organometallic residue. As shown in FIG. 3B, a residue remained on the support when treated by immersing the corroded wafer prepared under the same process conditions in PRS-2000 at 65 ° C. for 10 minutes.

Example 4

Example 4 sets forth comparative test results between Composition C as described above and stripping compositions described in US Pat. No. 4,770,713 and sold under the trademark ACT-150I.

ACT-150I is a dimethyl acetamide solvent based photoresist stripper.

Comparative test results are shown in FIGS. 4a and 4b with respect to the opening having a size of 1.0 μ. Each opening was on a silicon oxide dielectric layer that was corroded using a standard silicon oxide plasma corrosion process.

The photoresist was removed by oxygen plasma ashing. The support was then treated by immersion in the bar and Gangti composition C described above for 30 minutes at 45 ° C. Micrographs from the scanning electron microscopy as shown in FIG. 4A showed that Composition C completely removed all organometallic residues without damaging the silicon oxide support. 4B shows the support prepared under the same process conditions after soaking in ACT-150I for 30 minutes at 45 ° C. As shown in Figure 4b, the stripping composition only partially removed the corrosion residues.

Example 5

Example 5 describes the cleaning of polysilicon corrosion residues.

The microcircuit pattern of polysilicon on silicon oxide was corroded in a plasma corrosion apparatus using HBr as the corrosive gas. The photoresist was removed by oxygen plasma ashing. The corrosion residue, mostly Si-C-Br, remaining on the polysilicon circuit after removal of the photoresist is shown in Figure 5a. Upon further processing by immersing the wafer in Composition C of the present invention at 65 ° C. for 20 minutes, all corrosion residues were removed from the support as shown in FIG. 5B.

Example 6

Example 6 describes the cleaning of metal corrosion residues from a support. The sandwich metal support of TiW / Al-Si-Cu / TiW was patterned and corroded in a plasma metal corroder, namely Applied Material 8330 Metal Etcher. Since this metal corroder is a batch corrosive device, it can process more than one wafer at a time. Due to the corrosion mode carried out by the corrosion apparatus, less polymer residues are produced during corrosion. As shown in FIG. 6A, a residue remained on the metal wire after the photoresist was removed by oxygen plasma ashing. The wafer was then treated by immersing in composition B for 30 minutes at 65 ° C. as described above. As shown in Figure 6b, composition B serves to remove all organometallic residues from the surface.

Example 7

Example 7 includes a via hole or opening, i.e., in a support-like dielectric sheath layer having a size of 0.6 micron on a silicon oxide dielectric layer corroded using a standard silicon oxide plasma erosion process. The cleaning of the submicron circuit by the opening on the opening will be described. In particular, the oxide corrode sold by Lam Research was used. In this process, the corrosion residues are mostly silicone containing polymers with a small proportion of metals in the composition. The underlying layer was a metal support of TiN / Al-Si-Cu.

The photoresist masking material was removed by oxygen plasma ashing. The support was then treated by immersing in Composition A as described above at 60 ° C. for 30 minutes. Cross-sectional micrographs from the scanning microscope, as shown in FIG. 7A, showed that Composition A removes all organometallic residues. However, as shown in Figure 7b, residues remaining inside the opening when the corroded wafer is processed under the same conditions. The ultrasonic bath was treated in a N-methyl-2-pyrrolidone solvent / alkanolamine based stripper at 90 ° C. for 60 minutes.

Example 8

A portion of the silicon oxide corrosion device made of heavy gauge aluminum was removed from the corrosion device for cleaning. A common procedure used to remove gaseous residues deposited on the corrosion apparatus is by sandblasting. However, sandblasting is a time consuming procedure. It has been found that residue adhering on the aluminum portion of the corrosion apparatus can be easily removed by immersing it in the composition of the present invention. The aluminum portion of the corrosion apparatus was immersed in Composition E for 30 minutes at 40 ° C. After rinsing and drying, it was observed that the residue was removed.

Example 9

Conventional processes for cleaning ceramic rings forming part of a metal corrosion apparatus include sandblasting or rubbing by hand. Composition A was used to wash the ceramic ring by immersing the ceramic ring in an ultrasonic bath at 35 ° C. for 45 minutes. It was found that the deposit was completely removed on the ceramic ring.

Example 10

Example 10 describes washing of metal corrosion residues.

Al-Si-Cu / W / TiW metal patterns settled on the plasma enhanced TEOS were used. The wafer was 50% overcorroded. P-5000, sold by Applied Material, was used for metal corrosion. P-5000 is a single wafer corroder and, due to the processing technology of the corrosive device, after corrosion the higher stacked polymer remains more difficult to remove than described in Examples 6 and 7 above. A sandwich metal support of Al-Si-Cu / W / TiW was patterned and corroded in a plasma metal corroder P-5000. After removal of the photoresist by oxygen plasma ashing, a small amount of residue remained on the corners of the metal wire and washed with Composition B at 65 ° C. for 30 minutes. The washed support is shown in Figure 8a. Composition B did not provide complete removal of the residue. Similar corroded wafers were then treated by immersing in Composition D as described above at 65 ° C. for 30 minutes. As shown in Figure 8b, Composition D removed all organometallic residues from the surface. Composition B does not contain a chelating agent, and Composition D contains a chelating agent.

It is assumed that the activity of composition B began to decrease because of its short-term effects based on the absence of chelating agent.

Example 11

Example 11 demonstrates that chelating agent containing wash solutions have increased stability compared to wash solutions containing no chelating agent. As described in Table 1, Compositions A, C and G were each placed in separate sealed Pyrex flasks and maintained at room temperature for a period of 80 days. Samples were taken from each plasma at regular intervals and analyzed to determine their activity. The activity of the wash composition was measured by the reduction potential of hydroxylamine.

It can be seen from FIG. 9 that compositions G and A that do not contain chelating agents lose their activity much faster than composition C.

Examples 12-26 below further illustrate the wash solutions prepared according to the present invention. Examples 12-20 describe wash solutions having a long-term effect due to the inclusion of catechol or dihydroxybenzene as chelating agents. Examples 21-26 describe wash solutions having a short term effect since they do not contain chelating agents.

The procedure used for Examples 12-26 included mixing the composition components together and then heating the mixture to 65 ° C. The wafer sample was then immersed in the wash solution for 30 minutes with infrequent stirring. The wafer specimen was then placed in N-methyl-2-pyrrolidinone having a temperature of 80-85 ° C. for 10 minutes. Thereafter, the wafer specimens were rinsed in a water bath. In some examples, the wash solution was serially diluted with the addition of 20 parts water, and new wafer specimens were treated therein using the same procedure for comparison purposes. The dry wafers were evaluated by SEM air blowing. When used in the examples, DGA represents diglycolamine, also known as 2-amino-2-ethoxy ethanol, DMSO represents dimethylsulfoxide, and catechol is 1,2-dihydroxybenzene.

Example 12

A wash solution comprising 35 parts hydroxylamine (50% aqueous), 27 parts DGA, 5 parts catechol and 33 parts DMSO was prepared and used to clean the wafer. The wafer had a polysilicon structure and was thoroughly cleaned without damaging the structure by the cleaning solution. Plasma corrosion residues on the wafers containing the via holes were also washed.

The wash solution was then diluted with 20 parts water and fresh wafer specimens were washed using the solution. Additional water did not reduce the ability of the solution to clean the polysilicon structure. Corrosion residues were satisfactorily removed from the wafer specimen.

Example 13

A wash solution containing 34 parts hydroxylamine (50 parts aqueous), 5 parts catechol, 54 parts N-methyl-2-pyrrolidinone and 7 parts tetramethylammonium hydroxide (25% aqueous) was prepared, and the metal structure It was used to clean the wafer with. The corrosion residues on the wafers were cleaned without leaving evidence of erosion.

Thereafter, the wash solution was diluted with 20 parts water. The via holes in the wafer were washed with the dilution solution leaving no evidence of cutting off the bottom of the support.

Example 14

A wash solution was prepared containing 35 parts hydroxylamine (50% aqueous), 59 parts DGA, 5 parts t-butyl-catechol and 1 part water. The solution was used to clean a wafer having a polysilicon structure.

The wafer was washed without perforating the support.

Thereafter, 20 parts of water was added to the wash solution. The dilution solution was used to wash fresh wafer specimens. Dilution of the cleaning solution did not reduce the cleaning effect of the solution on the polysilicon structure. Each of the solutions of Example 14 were satisfactorily effective against the via holes without evidence of cutting the bottom of the wafer support.

Example 15

A wash solution was prepared containing 35 parts hydroxylamine (50% aqueous), 45 parts DGA, 5 parts catechol and 15 parts tetramethylammonium hydroxide (25% aqueous). The cleaning solution provided good cleaning of the polysilicon structure without puncturing the support.

Example 16

A wash solution containing 60 parts DGA, 5 parts catechol and 35 parts N, O-dimethylhydroxylamine (50% aqueous) was prepared. The cleaning solution provided good cleaning of the polysilicon structure and gave very satisfactory results for the cleaning of the via holes.

The wash solution was then diluted with 20 parts water and used to wash new wafers. Dilution of the wash solution did not reduce the wash power of the solution.

Example 17

A wash solution was prepared containing 51 parts DGA, 5 parts catechol, 31 parts methoxylamine hydrochloride and 13 parts water. The cleaning solution cleaned the metal structure without eroding the structure.

Subsequently, when 20 parts of water were added to the wash solution to dilute the solution, the diluted solution was known to wash the polysilicon and via hole forms without apparent erosion of the metal structure.

Example 18

A wash solution containing 60 parts DGA, 5 parts catechol, and 35 parts N, N-diethylhydroxyl amine was prepared. The cleaning solution cleaned the metal structure without apparent erosion of the structure.

When the wash solution was diluted with 20 parts water, the solution thoroughly washed the via holes and the metal structures.

Example 19

A wash solution containing 61 parts DGA, 5 parts catechol, and 34 parts acetohydroxysamic acid was prepared. The cleaning solution provided acceptable polysilicon wafer cleaning.

Continuous dilution of the wash solution with 20 parts water did not affect the ability of the solution to clean the via hole structures in the wafer.

Example 20

A wash solution containing 60 parts DGA, 5 parts catechol, and 35 parts methylhydrazine was prepared. The cleaning solution gave excellent results for cleaning the wafer via holes.

Subsequent dilution of the wash solution with 20 parts water did not significantly reduce the ability of the dragon to clean the via holes with plasma corrosion residues at a distance.

Example 21

A wash solution was prepared containing 49 parts DGA, 4 parts catechol, 29 parts methylhydrazinocarboxylate and 18 parts water. The cleaning solution was effective to clean the polysilicon and via hole structures.

Example 22

A washing solution having a short term effect was prepared containing 35 parts hydroxylamine (50% aqueous), 60 parts DGA and 5 parts dimethylgloxime. When used immediately after its preparation, the wash solution gave acceptable results for cleaning the via holes.

When 18 parts water was continuously added to the wash solution, the plasma corrosion residues of the via holes were still effectively washed by the dilute solution.

Example 23

A wash solution containing 60 parts DGA and 40 parts N, O-dimethylhydroxylamine (50% aqueous) was prepared. When used immediately after the preparation of the solution, the wash solution cleaned the polysilicon structure without problems.

Example 24

A wash solution containing 53 parts DGA, 33 parts N-methylhydroxylamine hydrochloride, and 14 parts water was prepared. When used immediately after the preparation of the solution, the cleaning solution cleaned the polysilicon structure and via holes without deleterious effects.

Example 25

A wash solution was prepared containing 60 parts DGA and 40 parts N, N-diethylhydroxylamine and 20 parts water. When the solution was used immediately after its preparation, the wash solution washed the polysilicon structure without eroding results.

Example 26

A wash solution containing 60 parts DGA and 40 parts hydroxylamine (50% aqueous) was prepared. The wash solution thoroughly washed the polysilicon structures, via holes and metal structures. However, after about one week, the solution lost its effect even if the composition did not change. At that time, 5 parts of catechol were added to the solution to reactivate the solution. The reactivated solution could include the via holes to clean the wafer structure again.

When diluting the reactivated wash solution with 18 parts water, it was found that the wash force of the solution did not decrease.

From the various test results listed in the Examples, it can be seen that the cleaning solutions of the present invention provide novel and surprising results.

The composition is applicable to various modifications while allowing a simple method of use and still providing the desired results. Therefore, the composition of the present invention allows wide application with slight adjustments.

As will be apparent to those skilled in the art, various modifications may be made within the scope of the foregoing description. Such modifications, within the ability of those skilled in the art, form part of the invention and are covered by the appended claims.

Claims (21)

(a) (1) the following general formula (I) Wherein R ₁ , R ₂ , R ₃ and R ₄ are the same or different and represent a hydrogen; a hydroxyl group; a substituted C ₁ -C ₆ straight chain, branched or cycloalkyl, alkenyl or alkynyl group; a substituted acyl group; Linear or branched alkoxy group; amidyl group; carboxyl group; alkoxyalkyl group; alkylamino group; alkyl sulfonyl group; and sulfonic acid group; x = 0 when y = 1 or x = 0 or 1 when y = 0 ; y = 0 at x = 1 or y = 0 or 1 at x = 0; R ₄ is present only at x = 1; or a salt thereof; (2) the following General Formula (II) Wherein R ₅ , R ₆ , and R ₇ are independently hydrogen; a hydroxyl group; a substituted C ₁ -C ₆ straight, branched or cycloalkyl, alkenyl or alkynyl group; substituted acyl, straight or branched alkoxy A group, an amidyl group, a carboxyl group, an alkoxyalkyl group, an alkylamino group, an alkylsulfonyl group, or a sulfonic acid group), or a salt and a derivative thereof; (3) the following general formula (III) Wherein R ₈ , R ₉ , and R ₁₀ are independently hydrogen, substituted C ₁ -C ₆ straight chain, branched or cycloalkyl, alkenyl or alkynyl groups, substituted acyl groups, straight or branched alkoxy groups, amidyl groups , A carboxyl group, an alkoxyalkyl group, an alkylamino group, an alkylsulfonyl group, or a sulfonic acid group.) Or a salt thereof; And (4) the following general formula (IV) Wherein R ₁₁ , R ₁₂ , R ₁₃ and R ₁₄ are independently hydrogen; a hydroxyl group; a substituted C ₁ -C ₆ straight, branched or cycloalkyl, alkenyl or alkynyl group; a substituted acyl group, a straight chain or At least one nucleophilic amine compound having an oxidation and reduction potential selected from the group consisting of compounds having a branched alkoxy group, an amidyl group, a carboxyl group, an alkoxyalkyl group, an alkylamino group, an alkyl sulfonyl group, or a sulfonic acid group. 50% by weight, (b) 10-80% by weight of one or more organic solvents miscible with the nucleophilic amine compound, and (c) the remaining amount of water, wherein the nucleophilic amine compound and the organic solvent are supported Is present in an amount sufficient to remove corrosion residues and resists from said nucleophilic amine compound, wherein said nucleophilic amine compound is different from said organic solvent. The method according to claim 1, wherein (1) the following general formula (V) (Wherein R ₁₅ and R ₁₆ may be any of H, t-butyl, OH, or COOH); (2) the following General Formula (VI) Wherein R ₁₇ is OH or COOH; (3) the following general formula Ethylene diamine tetracarboxylic acid and ammonium salts thereof, wherein R ₁₈ , R ₁₉ , R ₂₀ and R ₂₁ may be H or NH ₄ ; And (4) alkyl ammonium hydroxide of the general formula R ₁ R ₂ R ₃ R ₄ NOH, wherein R ₁ , R ₂ , R ₃ and R ₄ can independently be H or a short chain alkyl group having 1 to 5 carbon atoms Further comprising 2.5-30% by weight of at least one compound selected from the group consisting of component (d), wherein the nucleophilic amine compound and organic solvent and component (d) remove resist and corrosion residue from the support A composition present in an amount sufficient to The composition of claim 1 or 2, wherein said organic solvent is an alkanolamine. The composition of claim 3, wherein the alkanol group contains 1 to 5 carbon atoms. 4. The composition of claim 3, wherein said alkanolamine is selected from the group consisting essentially of monoamines, diamines, and triamines. The alkanolamine of claim 3, wherein R ₁ and R ₂ are H, CH ₃ , CH ₃ CH | ₂ or CH ₂ CH ₂ OH R ₁ R ₂ -N-CH ₂ CH ₂ -O-CH | Composition with ₂ CH ₂ OH. 4. The composition of claim 3, wherein said alkanolamine is an amino alkoxy alkanol. The composition according to claim 1 or 2, wherein the nucleophilic amine compound is hydroxylamine or a derivative thereof. The composition according to claim 1 or 2, wherein the nucleophilic amine compound is hydrazine or a derivative thereof. The composition of claim 2, wherein said compound (d) is dihydroxybenzene, derivatives thereof, or mixtures thereof. The composition of claim 1 wherein component (a) is hydroxylamine and component (b) comprises diglycolamine. The composition of claim 2 wherein component (a) is hydroxylamine, component (b) comprises diglycolamine and component (d) comprises catechol. The composition of claim 12, wherein the catechol is present in an amount of at least 2% by weight. The composition according to claim 11, wherein the diglycolamine is present in an amount of at least 60% by weight. The composition of claim 11, wherein the hydroxylamine and water are present in a ratio of 50:50. The composition of claim 15 wherein the hydroxylamine and water are each present in an amount of 17.5% by weight. Removing the corrosion residue or resist from the support, consisting of contacting the support having the resist or corrosion residue with the composition according to claim 1 for a time sufficient to remove the corrosion residue or resist from the support. How to. 18. The method of claim 17, wherein the nucleophilic amine compound is kept separate from the organic solvent until the composition is used to remove resist or corrosion residues from the support. 19. The method of claim 17 or 18, wherein the support is a semiconductor wafer. The method of claim 17 or 18, wherein the temperature is in the range of room temperature to 100 ° C. 19. 19. The method of claim 17 or 18, wherein the time is in the range of 2 to 60 minutes.