Hydroxylamino cleaning solution and application thereof in semiconductor aluminum interconnection process

Abstract

The invention relates to the technical field of semiconductor manufacturing, in particular to hydroxylamine cleaning fluid and application of the hydroxylamine cleaning fluid in a semiconductor aluminum interconnection process, and the hydroxylamine cleaning fluid comprises the following components in percentage by weight: 5-30% of a component a and water; a component b: 0.01-30% of hydroxylamine and hydroxylamine salt; a component c: 0.1-70% of an alkaline organic compound; a component d: 1-20% of organic acid; a component e: 0.001%-2% of a corrosion inhibitor; 5%-20% of a component f which is an organic solvent; the pH value of the composition is 9-12. Aiming at corrosion of the aluminum, the aluminum alloy and the like, the hydroxylamine-based cleaning solution and the cleaning method have the advantages that high cleaning performance is kept, and corrosion resistance to the metal aluminum and the aluminum alloy can be realized.

Description

Technical Field

[0001] This invention relates to the field of semiconductor manufacturing technology, and in particular to a hydroxylamine-based cleaning solution and its application in semiconductor aluminum interconnect processes. Background Technology

[0002] In integrated circuit manufacturing, photoresist is an essential process step for patterning components through a series of coating, exposure, and imaging steps. Before proceeding to the next process at the end of patterning (i.e., after coating, exposure, imaging, ion implantation, and etching of the photoresist layer), any residue of the photoresist material must be thoroughly removed. Ion bombardment during the doping step hardens the photoresist polymer, making the residue less soluble and thus more difficult to remove. Generally, this stage uses a two-step method (dry ashing and wet cleaning) to remove the photoresist film. The first step uses plasma or reactive gas to decompose and remove most of the organic photoresist layer; the second step uses a cleaning solution to remove and clean away the remaining photoresist layer and inorganic matter without corroding or damaging metal layers, such as aluminum and aluminum alloys.

[0003] Currently, wet cleaning solutions are mainly developed by EKC and ACT, and hold a significant market share. For example, EKC Technology Inc.'s EKC265 and EKC270 cleaning solutions are post-etching cleaning solutions primarily composed of water, alkanolamines, catechols, and hydroxylamine. Such compositions are disclosed in Lee's U.S. Patent No. 5,279,771. Ashland Chemical's ACT935 cleaning solution primarily consists of water, alkanolamines, and hydroxylamine. Such compositions are disclosed in Ward's U.S. Patent No. 5,419,779. Mitsubishi Gas Chemical's ELMC-30 cleaning solution primarily consists of water, N,N-dimethylformamide, fluorinated compounds, organic carboxylates, and sugar alcohols, where the sugar alcohols act as etchants. Such compositions are disclosed in Aoyama et al.'s U.S. Patent No. 5,630,904.

[0004] While these commercially available products effectively decompose residues from plasma etching and ashing, they also damage the vapor-deposited patterns of metals and oxides on the substrate. This is because EKC265 and ACT935 have a pH above 11, and ELMC-30 contains fluorine compounds. These products lack corrosion inhibitors, which are completely ineffective in preventing corrosion of metal layers such as copper, aluminum, and aluminum alloys (e.g., Al-Cu-Si), which are particularly sensitive to corrosion. Adding appropriate corrosion inhibitors, without hindering the removal of plasma etching residues, is essential to prevent corrosion of the substrate's metal layers.

[0005] Therefore, there is a need for novel cleaning compositions for removing plasma etching residues from substrates. Additionally, there is a need for cleaning compositions that do not have a harmful effect on the substrate, and for cleaning compositions that are water-soluble, non-hazardous, and do not harm the environment. Summary of the Invention

[0006] The purpose of this invention is to provide a hydroxylamine-based cleaning solution and its application in semiconductor aluminum interconnect processes. This cleaning solution maintains the cleaning ability of traditional hydroxylamine-based cleaning solutions, while reducing or minimizing corrosion of metals by rationally adjusting the formulation structure and adding appropriate corrosion inhibitors.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a hydroxylamine-based cleaning solution, comprising, by weight percentage: Ingredient a: 5-30%, water; Ingredient b: 0.01-30%, hydroxylamine and hydroxylamine salts; Component c: 0.1-70%, alkaline organic compounds; Ingredient d: 1-20%, organic acids; Ingredient e: 0.001-2%, corrosion inhibitor; Ingredient f: 5-30%, organic solvent; The composition has a pH value of 9-12.

[0008] Preferably, component b is at least one compound selected from hydroxylamine, hydroxylamine sulfate, hydroxylamine hydrochloride, hydroxylamine nitrate, and hydroxylamine phosphate.

[0009] Preferably, component c is at least one compound selected from methylamine, aniline, ethylamine, dimethylamine, diethylamine, triethylamine, ammonia, 3-diethylaminopropylamine, tetramethylammonium hydroxide, tetraethylamine hydroxide, tetrabutylamine hydroxide, cyclohexylamine, ethanolamine, diethanolamine, triethanolamine, isopropanolamine, 2-amino-2-methyl-1-propanol (AMP95), N-methyldiethanolamine, N-ethyldiethanolamine, diethylene glycolamine, n-butanolamine, triisopropanolamine, morpholine, and N-aminoethylpiperazine.

[0010] Preferably, component d is at least one compound selected from citric acid, lactic acid, acetic acid, propionic acid, malic acid, tartaric acid, malonic acid, oxalic acid, succinic acid, gluconic acid, glycolic acid, diethanolic acid, maleic acid, benzoic acid, phthalic acid, salicylic acid, catechol, resorcinol, and hydroquinone.

[0011] Preferably, component e is at least one compound selected from benzotriazole, 5-aminotetrazole, pyrazole, imidazole, 3-amino-1,2,4-triazole, 4-amino-1,2,4-triazole, 1,2,4-triazole, methylbenzotriazole, 5-carboxybenzotriazole, adenine, and glycine.

[0012] Preferably, component f is at least one compound selected from sulfoxide, sulfone, pyrrolidone, and ether, wherein the sulfoxide is dimethyl sulfoxide; the sulfone is sulfolane; the pyrrolidone is N-methylpyrrolidone; and the ether is at least one compound selected from propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, propylene glycol monoethyl ether, and propylene glycol monobutyl ether.

[0013] The application of the hydroxylamine-based cleaning solution as a cleaning composition for removing plasma etching residues and / or ashing residues.

[0014] A method for cleaning a semiconductor device includes the following steps: Plasma etching process is performed on semiconductor substrates; The process of ashing the photoresist for semiconductor substrates; A cleaning process using hydroxylamine-based cleaning solution to clean plasma etching residues and ashing residues formed on the semiconductor substrate during the etching process and the ashing process. The semiconductor substrate contains aluminum and / or aluminum alloys.

[0015] Compared with the prior art, the beneficial effects of the present invention are: In response to the corrosion of aluminum, aluminum alloys, etc., the hydroxylamine-based cleaning solution and cleaning method designed in this application can maintain cleaning performance while achieving corrosion prevention. Attached Figure Description

[0016] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0017] Figure 1 This is a table showing the component ratios of the hydroxylamine-based cleaning solution of the present invention. Detailed Implementation

[0018] A hydroxylamine-based cleaning solution, comprising, by weight percentage: Ingredient a: 5-30%, water; Ingredient b: 0.01-30%, hydroxylamine and hydroxylamine salts; Component c: 0.1-70%, alkaline organic compounds; Ingredient d: 1-20%, organic acids; Ingredient e: 0.001-2%, corrosion inhibitor Ingredient f: 5-30%, organic solvent The composition has a pH value of 9-12.

[0019] Specifically, component b is at least one compound selected from hydroxylamine, hydroxylamine sulfate, hydroxylamine hydrochloride, hydroxylamine nitrate, and hydroxylamine phosphate.

[0020] Further selection of component b as hydroxylamine.

[0021] Preferably, component c is at least one compound selected from methylamine, aniline, ethylamine, dimethylamine, diethylamine, triethylamine, ammonia, 3-diethylaminopropylamine, tetramethylammonium hydroxide, tetraethylamine hydroxide, tetrabutylamine hydroxide, cyclohexylamine, ethanolamine, diethanolamine, triethanolamine, isopropanolamine, 2-amino-2-methyl-1-propanol (AMP95), N-methyldiethanolamine, N-ethyldiethanolamine, diethylene glycolamine, n-butanolamine, triisopropanolamine, morpholine, and N-aminoethylpiperazine.

[0022] Further selection of component c as an organic alcohol amine with hydroxyl groups.

[0023] Further select component c as at least one compound selected from ethanolamine, triethanolamine, isopropanolamine, diethylene glycolamine, and 2-amino-2-methyl-1-propanol (AMP95).

[0024] Preferably, component d is at least one compound selected from citric acid, lactic acid, acetic acid, propionic acid, malic acid, tartaric acid, malonic acid, oxalic acid, succinic acid, gluconic acid, glycolic acid, diethanolic acid, maleic acid, benzoic acid, phthalic acid, salicylic acid, catechol, resorcinol, and hydroquinone.

[0025] Further selection of component d revealed it to be a phenol.

[0026] Further selection: component d is at least one compound selected from catechol, resorcinol, and hydroquinone.

[0027] Preferably, component e is at least one compound selected from benzotriazole, 5-aminotetrazole, pyrazole, imidazole, 3-amino-1,2,4-triazole, 4-amino-1,2,4-triazole, 1,2,4-triazole, methylbenzotriazole, 5-carboxybenzotriazole, adenine, and glycine.

[0028] Further selection, component e is at least one compound selected from 5-aminotetrazole, 3-amino-1,2,4-triazole, 4-amino-1,2,4-triazole, 1,2,4-triazole, and pyrazole.

[0029] Preferably, component f is at least one compound selected from sulfoxide, sulfone, pyrrolidone, and ether, wherein the sulfoxide is dimethyl sulfoxide; the sulfone is sulfolane; the pyrrolidone is N-methylpyrrolidone; and the ether is at least one compound selected from propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, propylene glycol monoethyl ether, and propylene glycol monobutyl ether.

[0030] Further selection revealed that component f is an ether.

[0031] Further selection: component f is at least one compound selected from propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, propylene glycol monoethyl ether, and propylene glycol monobutyl ether.

[0032] The application of the hydroxylamine-based cleaning solution as a cleaning composition for removing plasma etching residues and / or ashing residues.

[0033] A method for cleaning a semiconductor device includes the following steps: Plasma etching process is performed on semiconductor substrates; The process of ashing the photoresist for semiconductor substrates; A cleaning process using hydroxylamine-based cleaning solution to clean plasma etching residues and ashing residues formed on the semiconductor substrate during the etching process and the ashing process. The semiconductor substrate contains aluminum and / or aluminum alloys.

[0034] The present invention will be further illustrated by the following examples.

[0035] Examples 1-16 Table 1 Examples 1-16 Determination of Al corrosion rate An Al film (50 nm thick) was sputtered onto an alkali-free glass substrate for LCD (liquid crystal display). The sample substrate with the Al film was cut into approximately 0.5 cm pieces to obtain sample sheets. 100 ml of the cleaning solution described in Table 1 for each embodiment was added to a 250 ml beaker and heated to 65°C. One sample sheet with the Al film was simultaneously added to each of these cleaning solutions, and the time it took for each sputtered film to completely disappear was visually observed. This measurement was performed three times, and the average corrosion rate of Al was calculated from these results. Table 2 summarizes the corrosion rate arrays of aluminum in each embodiment.

[0036] Determination of the corrosion rate of SiO2: SiO2 films (50 nm thick) were sputtered onto an alkali-free glass substrate for LCD (liquid crystal display). The SiO2-coated sample substrates were cut into approximately 0.5 cm pieces to obtain sample sheets. 100 ml of the cleaning solution described in Table 1 for each embodiment was added to a 250 ml beaker and heated to 65°C. One sample sheet with the SiO2 film was simultaneously added to this cleaning solution and immersed for 30 min. After rinsing with IPA, the sample sheets were dried with high-purity nitrogen gas, and the SiO2 thickness (T1) was measured using a Nanospec 6100 thickness gauge. The average corrosion rate of SiO2 was calculated from these results. Table 2 summarizes the SiO2 corrosion rate arrays for each embodiment.

[0037] Determination of cleaning effect of Al process chips: Take an aluminum integrated circuit sample after plasma etching and ashing, and cut the sample substrate into pieces of approximately 0.5 cm to obtain sample wafers. Add 100 ml of the cleaning solution composed of each embodiment shown in Table 1 to a 250 ml beaker and heat to 65°C. Simultaneously add one of the above sample wafers to the cleaning solution, soak for 30 minutes, remove the sample wafers, rinse with IPA, and then dry with nitrogen. Observe the surface cleaning effect of each sample wafer using SEM.

[0038] As shown in Table 2, the cleaning solution composition of this invention exhibits corrosion rates of less than 3 A / min for all aluminum and aluminum alloys in integrated circuits, and less than 1 A / min for non-metallic SiO2. Furthermore, this cleaning solution effectively removes residues after plasma etching and ashing, without corroding either metals or non-metals. This demonstrates that the hydroxylamine-based cleaning solution of this invention has low corrosion rates for both metals and non-metals, and can clean three types of wafers: metal lines, channels, and metal pads.

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A hydroxylamine-based cleaning solution, characterized in that: Includes, by weight percentage: Ingredient a: 5-30%, water; Ingredient b: 0.01-30%, hydroxylamine and hydroxylamine salts; Component c: 0.1-70%, alkaline organic compounds; Ingredient d: 1-20%, organic acids; Ingredient e: 0.001-2%, corrosion inhibitor; Ingredient f: 5-30%, organic solvent; The composition has a pH value of 9-12.

2. The hydroxylamine-based cleaning solution according to claim 1, characterized in that: Component b is at least one compound selected from hydroxylamine, hydroxylamine sulfate, hydroxylamine hydrochloride, hydroxylamine nitrate, and hydroxylamine phosphate.

3. The hydroxylamine-based cleaning solution according to claim 1, characterized in that: The component c is a compound selected from at least one of methylamine, aniline, ethylamine, dimethylamine, diethylamine, triethylamine, ammonia, 3-diethylaminopropylamine, tetramethylammonium hydroxide, tetraethylamine hydroxide, tetrabutylamine hydroxide, cyclohexylamine, ethanolamine, diethanolamine, triethanolamine, isopropanolamine, 2-amino-2-methyl-1-propanol, N-methyldiethanolamine, N-ethyldiethanolamine, diethylene glycolamine, n-butanolamine, triisopropanolamine, morpholine, and N-aminoethylpiperazine.

4. The hydroxylamine-based cleaning solution according to claim 1, characterized in that: The component d is at least one compound selected from citric acid, lactic acid, acetic acid, propionic acid, malic acid, tartaric acid, malonic acid, oxalic acid, succinic acid, gluconic acid, glycolic acid, diethanolic acid, maleic acid, benzoic acid, phthalic acid, salicylic acid, catechol, resorcinol, and hydroquinone.

5. The hydroxylamine-based cleaning solution according to claim 1, characterized in that: The component e is at least one compound selected from benzotriazole, 5-aminotetrazole, pyrazole, imidazole, 3-amino-1,2,4-triazole, 4-amino-1,2,4-triazole, 1,2,4-triazole, methylbenzotriazole, 5-carboxybenzotriazole, adenine, and glycine.

6. The hydroxylamine-based cleaning solution according to claim 1, characterized in that: The component f is at least one compound selected from sulfoxide, sulfone, pyrrolidone, and ether.

7. The hydroxylamine-based cleaning solution according to claim 6, characterized in that: The sulfoxide is dimethyl sulfoxide; the sulfone is sulfolane; the pyrrolidone is N-methylpyrrolidone; and the ether is at least one compound selected from propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, propylene glycol monoethyl ether, and propylene glycol monobutyl ether.

8. The use of the hydroxylamine cleaning solution according to any one of claims 1-7 as a cleaning composition for removing photoresist residues after plasma etching and / or ashing.

9. A method for cleaning a semiconductor device, characterized in that: Includes the following steps: For performing plasma etching processes on semiconductor substrates; The photoresist for semiconductor substrates undergoes an ashing process. A cleaning process using hydroxylamine-based cleaning solution to clean plasma etching residues and ashing residues formed on the semiconductor substrate during the etching process and the ashing process. The semiconductor substrate contains aluminum and / or aluminum alloys.

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