JP2004155822A - Cleaning agent - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cleaning agent without attacking copper during cleaning of the copper used in a wiring material of a semiconductor device. <P>SOLUTION: The cleaning agent comprises cyanoalkylamines. Cyanoethylamines can preferably be used as the cyanoalkylamines. N-(2-cyanoethyl)trimethylenediamine, N-(2-cyanoethyl)-N-methylethylenediamine, N-(2-cyanoethyl)-N-methyltrimethylenediamine, N-methyl-N-(2-cyanoethyl)amine, etc., can specifically be used. <P>COPYRIGHT: (C)2004,JPO

Description

実施例３〜７
銅メッキしたウェハを、１１７ｎｍの平均粒子径を有するシリカゾルを分散させた純水に３分浸漬した後、ｐＨ６に調整した希硫酸で１分洗浄した。これを乾燥し、シリカ粒子で汚染されたウエハとした。このウエハを表２に示す洗浄液中で室温で１分間、超音波洗浄し、その後水洗、乾燥した。表面を走査型電子顕微鏡で観察し、単位面積あたりのシリカ粒子数を調べた。なお、シリカ粒子の除去性能は以下の様に評価した。
【００２９】
粒子除去率（％）＝１００−（洗浄液で超音波洗浄した場合のシリカ粒子数／純水のみで超音波洗浄した場合のシリカ粒子数）×１００
【００３０】
【表２】

【発明の効果】
本発明の洗浄剤は、優れた洗浄能力を示すとともに、銅を腐食しない洗浄剤として使用できる。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to copper cleaning agents. More specifically, the present invention relates to a cleaning agent for a copper wiring semiconductor device.
[0002]
[Prior art]
2. Description of the Related Art In recent years, with the rapid progress of information technology, there has been a trend to increase the speed by miniaturization, higher density, and higher integration of large-scale integrated circuits (LSI, ULSI, VLSI). Development is taking place. In order to achieve multi-layered wiring, it is necessary to reduce the wiring pitch width and the capacitance between wirings, etc.As a solution for reducing the wiring pitch width, tungsten and aluminum, which are existing metal wiring materials, have a higher resistivity. Technology development for changing to low copper (Cu) is being vigorously studied.
[0003]
Copper is easily corroded by ammonia or amines, and there is a need to change the cleaning agent used for conventional aluminum wiring.
[0004]
For example, when finally removing a resist used in forming wiring, a monoethanolamine-based resist stripping agent used in conventional aluminum wiring has extremely high copper corrosion, and its replacement is required.
[0005]
In addition, a damascene process by embedding tends to be the mainstream for copper wiring. The flattening of the wiring buried by the damascene method is performed by a so-called CMP (Chemical Mechanical Polishing) method utilizing the synergistic property of the mechanical polishing action and the chemical polishing action, and the copper wiring material is polished by the same method. Has been made.
[0006]
However, in this CMP method, a large amount of abrasives, polishing debris, and metal impurities adhere to the wafer after metal polishing, so that the wafer surface needs to be cleaned. When washing with an alkaline solution, reattachment of impurities can be suppressed, so that ammonia has been generally used for metals other than copper. However, in the case of copper, it was easily corroded by ammonia, and ammonia could not be used as a cleaning agent.
[0007]
Accordingly, a method has been proposed in which a corrosion inhibitor of copper is added to ammonia to reduce the corrosion rate of copper. For example, Patent Document 1 discloses a compound containing a mercapto group as an anticorrosive. However, as described in the publication, the compound containing a mercapto group has a peculiar unpleasant odor, and there is a problem in using it environmentally and industrially. Aromatic compounds such as benzotriazole are known as other anticorrosives, but they have environmental problems such as high toxicity. In addition, in the method of adding an anticorrosive, it is not possible to suppress the corrosion of copper with a small amount of the anticorrosive. Therefore, a method that basically does not use ammonia, which easily corrodes copper, has been desired.
[0008]
As described above, conventional cleaning agents containing ammonia and amines are not sufficient in terms of corrosiveness to copper.
[0009]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 2000-273663 (Claims)
[0010]
[Problems to be solved by the invention]
An object of the present invention is to provide a cleaning agent that does not attack copper in view of the above problems.
[0011]
[Means for Solving the Problems]
As a result of intensive studies on the cleaning agent, the present inventors have found that a cleaning agent containing a cyanoalkylamine can be used as a cleaning agent that does not attack copper, and have completed the present invention.
[0012]
That is, the present invention is a cleaning agent containing a cyanoalkylamine, and is useful for cleaning copper or an alloy containing copper.
[0013]
Hereinafter, the present invention will be described in more detail.
[0014]
An essential component of the cleaning agent of the present invention is a cyanoalkylamine. A cyanoalkylamine refers to a compound in which a nitrogen of an amine has a cyanoalkyl group. As the cyanoalkyl group, there are various groups such as a cyanomethyl group, a cyanoethyl group, and a cyanopropyl group. The cyanoethyl group is the most general and can be easily synthesized, and is industrially advantageous. Cyanoethylamines can be easily synthesized by adding acrylonitrile to amines with Michael, and cyanopropylamines can be synthesized by adding methacrylonitrile to amines.
[0015]
Examples of cyanoethylamines that can be used in the detergent of the present invention include N- (2-cyanoethyl) trimethylenediamine, N- (2-cyanoethyl) -N-methylethylenediamine, and N- (2-cyanoethyl) -N-methyl Trimethylenediamine, N-methyl-N- (2-cyanoethyl) amine, N- (2-cyanoethyl) -3-iminopropylamine, N, N-bis (2-cyanoethyl) -2-hydroxyethylamine, bis (2 -Cyanoethyl) methylamine, 4- (2-cyanoethyl) morpholine, 1- (2-cyanoethyl) -2-methylpiperidine, 1,4-bis (2-cyanoethyl) piperazine, 1- (2-cyanoethyl) piperazine, N -Alkyl (carbon number: 12 to 18) -N- [α-cyanoethyl poly (1-3) (aminotrimethyl ) -Ω-yl] amine, N, N-bis (2-cyanoethyl) -N- (2,3-dihydroxypropyl) amine, N-cyanoethyl-t-butylamine, N-cyanoethyl-N-alkyl (carbon number : 6 to 24) amine, N-cyanoethyl-N-alkenyl (carbon number: 6 to 24) amine, N- (2-cyanoethyl) ethylenediamine, monocyanoethylated diethylenetriamine, N- (β-cyanoethyl) hexamethylenediamine, N , N'-bis (β-cyanoethyl) hexamethylenediamine, α, ω-bis (cyanoethyl) diethylenetriamine, mono- or bis (β-cyanoethyl) 1,3,6-triaminomethylhexane, N- (cyanoethyl)- N- (cyanomethyl) methylamine, β-cyanoethylhydrazine, N- (2-cyanoethyl ) -N-cyclohexylamine, α, α, ω, ω-tetra (or tri, di, or mono) cyanoethylated polyalkylene polyamine, α, α, ω, ω-tricyanoethylated polyalkylene polyamine, α, α, ω, ω-dicyanoethylated polyalkylenepolyamine, α, α, ω, ω-monocyanoethylated polyalkylenepolyamine and the like are not particularly limited. These may be used alone or as a mixture of two or more.
[0016]
The cleaning agent of the present invention may contain components other than cyanoalkylamines.
Generally, water is added to use as an aqueous solution of a cyanoalkylamine, but a water-soluble organic solvent may be added to improve the detergency or the solubility of the cyanoalkylamine. As the water-soluble organic solvent, those commonly used as cleaning agents can be used. For example, alcohols such as methanol, ethanol, 1-propanol, 2-propanol, butanol, ethylene glycol, propylene glycol, polyethylene glycol, and benzyl alcohol, N, N-dimethylformamide, dimethylimidazolidinone, and N-methylpyrrolidone Examples include amides, sulfoxides such as dimethyl sulfoxide, and ethers such as tetrahydrofuran, dioxane, and diglyme.
[0017]
Other generally used anticorrosives and surfactants can also be added to the cleaning agent of the present invention. As for the anticorrosive, since the cleaning agent of the present invention has a very low copper corrosiveness, the effect is exhibited with the addition of the anticorrosive in a smaller amount than that generally added.
[0018]
Further, to the cleaning agent of the present invention, an acid or a salt may be added for improving cleaning performance or adjusting pH.
[0019]
The ratio of the cyanoalkylamines, water, and water-soluble organic solvent changes when the compound used is different, and it is difficult to limit the ratio. However, 0.01 to 80% by weight of the cyanoalkylamines and water are used. 0 to 99.99% by weight, and the organic solvent is 0 to 99.99% by weight (the total amount of the mixture is 100% by weight). Even if it is out of this range, it cannot be used, but the cleaning ability may be reduced.
[0020]
The cleaning agent of the present invention may be used by adding each component at the time of washing, or may be used after mixing each component in advance.
[0021]
The cleaning agent of the present invention can be used for cleaning copper wiring semiconductor devices. In particular, it is effective for a resist remover, a resist residue remover, and cleaning after CMP.
[0022]
After developing the resist and performing a process such as etching, the unnecessary resist, or unnecessary inorganic substances generated by the process such as etching are stripped and removed with a resist stripping agent and a resist residue stripping agent. The cleaning agent can remove these unnecessary resists and inorganic substances without damaging the copper wiring.
[0023]
In addition, polishing slurry, pad debris, and debris of a semiconductor material such as copper are present on the semiconductor device after the CMP, and the cleaning agent of the present invention removes and removes these debris without damaging the semiconductor material. can do.
[0024]
The use of the cleaning agent of the present invention reduces the corrosiveness to copper wiring. When using the cleaning agent of the present invention, cleaning may be promoted by heating, ultrasonic waves, or the like.
[0025]
【Example】
The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto.
[0026]
The following abbreviations have been used to simplify the notation.
[0027]
NH ₄ OH: ammonia water MEA: monoethanolamine CEEDA: N- (2- cyanoethyl) ethylenediamine CEM: 4-(2-cyanoethyl) morpholine BCEMA: bis (2-cyanoethyl) methylamine Examples 1-2, Comparative Example 1 ~ 2
A test piece of metallic copper was immersed in a 10% aqueous solution of amine shown in Table 1 at 50 ° C., and the copper corrosion rate was calculated from the weight change before and after immersion. The results are shown in Table 1.
[0028]
[Table 1]

Examples 3 to 7
The copper-plated wafer was immersed in pure water in which silica sol having an average particle diameter of 117 nm was dispersed for 3 minutes, and then washed with diluted sulfuric acid adjusted to pH 6 for 1 minute. This was dried to obtain a wafer contaminated with silica particles. This wafer was subjected to ultrasonic cleaning in a cleaning solution shown in Table 2 at room temperature for 1 minute, and then washed with water and dried. The surface was observed with a scanning electron microscope to determine the number of silica particles per unit area. The removal performance of the silica particles was evaluated as follows.
[0029]
Particle removal rate (%) = 100− (the number of silica particles when ultrasonically cleaned with a cleaning liquid / the number of silica particles when ultrasonically cleaned only with pure water) × 100
[0030]
[Table 2]

【The invention's effect】
The cleaning agent of the present invention exhibits excellent cleaning performance and can be used as a cleaning agent that does not corrode copper.

Claims (9)

A cleaning agent containing a cyanoalkylamine. The cleaning agent according to claim 1, wherein the component to be cleaned is copper or an alloy containing copper. The cleaning agent according to claim 1 or 2, wherein the cyanoalkylamine is a cyanoethylamine. When cyanoethylamines are N- (2-cyanoethyl) trimethylenediamine, N- (2-cyanoethyl) -N-methylethylenediamine, N- (2-cyanoethyl) -N-methyltrimethylenediamine, N-methyl-N- (2-cyanoethyl) amine, N- (2-cyanoethyl) -3-iminopropylamine, N, N-bis (2-cyanoethyl) -2-hydroxyethylamine, bis (2-cyanoethyl) methylamine, 4- (2 -Cyanoethyl) morpholine, 1- (2-cyanoethyl) -2-methylpiperidine, 1,4-bis (2-cyanoethyl) piperazine, 1- (2-cyanoethyl) piperazine, N-alkyl (carbon number: 12 to 18) -N- [α-cyanoethylpoly (aminotrimethylene) -ω-yl] amine, N, N-bis (2-sia Noethyl) -N- (2,3-dihydroxypropyl) amine, N-cyanoethyl-t-butylamine, N-cyanoethyl-N-alkyl (carbon number: 6 to 24) amine, N-cyanoethyl-N-alkenyl (carbon number) : 6 to 24) amine, N- (2-cyanoethyl) ethylenediamine, monocyanoethylated diethylenetriamine, N- (β-cyanoethyl) hexamethylenediamine, N, N′-bis (β-cyanoethyl) hexamethylenediamine, α, ω -Bis (cyanoethyl) diethylenetriamine, mono- or bis (β-cyanoethyl) 1,3,6-triaminomethylhexane, N- (cyanoethyl) -N- (cyanomethyl) methylamine, β-cyanoethylhydrazine, N- (2 -Cyanoethyl) -N-cyclohexylamine, α, α, ω, ω- Tracyanoethylated polyalkylene polyamine, α, α, ω, ω-tricyanoethylated polyalkylene polyamine, α, α, ω, ω-dicyanoethylated polyalkylene polyamine, α, α, ω, ω-monocyanoethylated polyalkylene The cleaning agent according to claim 2, wherein the cleaning agent is at least one selected from the group consisting of polyamines. The cleaning agent according to any one of claims 1 to 4, which is used for cleaning a semiconductor device. The cleaning agent according to claim 5, wherein the semiconductor device is a semiconductor device having a copper wiring. A semiconductor device cleaning method for cleaning a semiconductor device with the cleaning agent according to claim 1. A method for cleaning a semiconductor device, wherein the cleaning agent according to any one of claims 1 to 4 removes a resist of the semiconductor device or a resist residue. A semiconductor device cleaning method for cleaning a semiconductor device after chemical mechanical polishing with the cleaning agent according to claim 1.