KR-20260064296-A - CLEAN COMPOSITION FOR CERIA ABRASIVE PARTICLES

KR20260064296AKR 20260064296 AKR20260064296 AKR 20260064296AKR-20260064296-A

Abstract

The present invention relates to a composition for cleaning ceria abrasive particles, comprising an organic acid, a reducing agent, an ammonium halide compound, and an amino acid-based zwitterion compound, having a pH of 0 to 3.

Inventors

황샘
김찬미
이재성

Assignees

솔브레인 주식회사

Dates

Publication Date: 20260507
Application Date: 20241031

Claims (17)

It includes organic acids, reducing agents, ammonium halide compounds, and amino acid zwitterion compounds, and A composition for cleaning ceria abrasive particles having a pH of 0 to 3.
In claim 1, A composition for cleaning ceria abrasive particles, wherein the organic acid comprises one or more aliphatic or aromatic carboxylic acid compounds selected from the group consisting of monocarboxylic acids, dicarboxylic acids, and tricarboxylic acids, which may be substituted with at least one halogen atom.
In claim 2, A composition for cleaning ceria abrasive particles, wherein the above organic acid comprises a fluorinated aliphatic carboxylic acid compound.
In claim 3, The above organic acid is a composition for cleaning ceria abrasive particles, comprising trifluoroacetic acid.
In claim 1, The above reducing agent is a composition for cleaning ceria abrasive particles, comprising an organic reducing agent.
In claim 5, A composition for cleaning ceria abrasive particles, wherein the reducing agent comprises an organic reducing agent containing a reducing hydroxyl group or a thiol group.
In claim 6, A composition for cleaning ceria abrasive particles, wherein the reducing agent comprises an organic reducing agent containing an alcoholic or phenolic hydroxyl group.
In claim 7, A composition for cleaning ceria abrasive particles, comprising one or more reducing agents selected from the group consisting of ascorbic acid, kojic acid, gallic acid, vanillic acid, mercaptosuccinic acid, and 5-aminosalicylic acid, or reducing sugars.
In claim 1, The above ammonium halide compound is a composition for cleaning ceria abrasive particles, comprising an ammonium fluoride compound.
In claim 9, The above-mentioned ammonium halide compound is a composition for cleaning ceria abrasive particles, comprising tetraalkylammonium fluoride.
In claim 9, A composition for cleaning ceria abrasive particles, wherein the above-mentioned ammonium halogenated compound comprises one or more ammonium fluoride compounds selected from the group consisting of tetraethylammonium fluoride, tetramethylammonium fluoride, ammonium bifluoride, and ammonium fluoride.
In claim 1, A composition for cleaning ceria abrasive particles, wherein the above amino acid-based amphoteric ionic compound comprises a trialkylammonium alkyl carboxylate-based compound.
In claim 12, The above amino acid-based amphoteric ionic compound comprises a compound represented by the following formula (1), a composition for cleaning ceria abrasive particles: (In the above formula (1), R1 , R2 , and R3 are each independently hydrogen or an aliphatic alkyl group having 1 to 3 carbon atoms, and may be the same or different from each other, and L is an alkylene group having 1 to 10 carbon atoms that may have at least one of an aliphatic alkyl group having 1 to 6 carbon atoms, a hydroxyl group, a thiol group, a thioalkoxy group, an amino group, an amide group, a carboxyl group, an aromatic allocyclic group, and an aromatic heterocyclic group as a substituent, and R1 , R2 , and R3 may each be connected to each other to form a loop, or any one of R1 , R2 , and R3 may be connected to L to form a loop.
In claim 13, A composition for cleaning ceria abrasive particles, wherein the above-mentioned amphoteric compound comprises one or more selected from the group consisting of glycine, trimethylglycine, alanine, valine, leucine, isoleucine, proline, asparagine, serine, threonine, glutamine, cysteine, methionine, phenylalanine, tyrosine, tryptophan, aspartic acid, glutamic acid, histidine, lysine, and arginine.
In claim 1, A composition for cleaning ceria abrasive particles, comprising 100 parts by weight of an organic acid, 2.0 to 140 parts by weight of a reducing agent, 0.2 to 145 parts by weight of an ammonium halide compound, and 0.2 to 100 parts by weight of an amino acid-based amphoteric ionic compound.
In claim 1, A composition for cleaning ceria abrasive particles having a pH of 0 to 2.
In any one of claims 1 to 16, A composition for cleaning ceria abrasive particles, used to clean ceria abrasive particles having an average particle diameter (D 50 ) of 40 nm or less.

Description

Clean composition for ceria abrasive particles The present invention relates to a composition for cleaning ceria abrasive particles, and more specifically, to a cleaning composition for cleaning ceria particles used in a Chemical Mechanical Polishing (CMP) process. The wiring process, which is one of the manufacturing processes for semiconductor devices, includes a step of depositing a metal layer in grooves formed on a substrate (e.g., a semiconductor wafer) by embedding metal materials such as tungsten, copper, or aluminum into the grooves. After this metal layer deposition step, it is common practice to perform chemical mechanical polishing (CMP) and cleaning processes to remove unnecessary parts of the deposited metal layer and dielectric films, such as silicon oxide or silicon nitride films. In the CMP process, a slurry composition containing abrasives such as silica particles or ceria particles is typically used. If abrasives remain on the substrate after the CMP process, problems may arise that cause issues with the structure and characteristics of the semiconductor device or degrade the manufacturing yield and/or the quality of the manufactured product. To prevent these problems, a cleaning process is performed to remove the abrasives remaining on the substrate. Ceria, an abrasive used in the CMP process, has a higher removal rate (RR) and selectivity ratio at lower concentrations compared to silica, but there were difficulties in cleaning after polishing. As an alternative to this, a method of cleaning ceria residue using hydrofluoric acid or ammonia has been proposed (see Korean Registered Patent No. 712980 [Patent Document 1]). However, if hydrofluoric acid is used in the cleaning process, damage may occur to the substrate surface, which may increase surface roughness or cause defects on the substrate surface. Meanwhile, as devices become more miniaturized, the particle size of ceria abrasives is decreasing to a level of 40 nm or less based on the average particle diameter (D 50 ). This change in particle size affects the Ce³⁺ / Ce⁴⁺ ratio on the ceria surface, which in turn affects the number of Ce-O-Si bonds bonded to the substrate surface. Additionally, as the particle size of the ceria abrasive decreases, chemical bonding with the substrate surface increases, which resulted in the problem of residue remaining when using conventional cleaning methods such as hydrofluoric acid. A cleaning method for such fine ceria abrasives has been proposed using SPM (Sulfuric acid Peroxide Mixture), a mixture of sulfuric acid and hydrogen peroxide, as a cleaning solution (see Korean Registered Patent No. 1187341 [Patent Document 2]). Although SPM is a cleaning solution with excellent cleaning ability, it contains sulfuric acid, a strong acid, which causes serious environmental pollution upon disposal and poses a risk to workers. Therefore, there is a need for a cleaning composition that can remove residues of the slurry composition, abrasive particles, organic contaminants, metal contaminants, etc. generated after the CMP process without causing defects on the substrate surface, is environmentally friendly, and has reduced risk to the human body. The present invention will be described in detail below. In the present invention, "ceria particles" refers to cerium-based abrasive particles that include, for example , cerium oxide having the chemical formulas Ce₂O₃ and CeO₂ and can be included in a slurry during chemical mechanical polishing. In addition, in the present invention, "average particle size" is measured by a conventional method known in the art, and may be, for example, the particle size of the 50% cumulative distribution (D 50 ) in the particle size distribution map measured using a particle size analyzer (PSA). Furthermore, in the present invention, "zwitterion" refers to an ionic compound that contains equal amounts of positively charged functional groups and negatively charged functional groups within the molecule, thereby exhibiting overall electrical neutrality. Cleaning composition The composition for cleaning ceria abrasive particles according to the present invention comprises an organic acid, a reducing agent, an ammonium halide compound, and an amino acid-based zwitterion compound. At this time, the cleaning composition has a low pH of 0 to 3, so that ceria is stable in an ionic state and has the effect of facilitating the dissolution of ceria. Specifically, the cleaning composition may have a pH of 0 to 2 or 0 to 1. In particular, the cleaning composition has the effect of improving the cleaning power of the cleaning composition by reducing Ce 4+ to Ce 3+ and dissolving it with respect to ceria abrasive particles having a small particle size, specifically an average particle diameter (D 50 ) of 40 nm or less. organic acids Organic acids play a role in increasing the solubility of ceria particles by adjusting the pH of the composition. The above organic acid may include one or more alipha