CN-121991771-A - Chip cleaning agent and production method thereof

CN121991771ACN 121991771 ACN121991771 ACN 121991771ACN-121991771-A

Abstract

The invention relates to the technical field of cleaning agents, in particular to a chip cleaning agent and a production method thereof, wherein the chip cleaning agent is an aqueous cleaning agent for cleaning a copper-containing chip surface after chemical mechanical planarization, and comprises tartaric acid complexing agents and pH adjusting components, wherein the tartaric acid complexing agents are complexing agents capable of providing tartrate ions in an aqueous system in tartaric acid and/or tartrate, the pH adjusting components are used for adjusting the chip cleaning agent to near neutral working pH, so that the tartaric acid complexing agents take deprotonated tartrate ions as main forms, and the complex dissolution of copper oxide and the spontaneous dissolution of base copper are inhibited under the condition of not depending on strong acid or strong alkali. The tartrate ion is complexed with liquid copper ion to form soluble copper-tartaric acid complex to inhibit hydrolysis deposition and secondary oxide formation, and is dissolved with copper oxide residue to be taken away with liquid phase, and is adsorbed on surface to form adsorption layer to inhibit excessive dissolution and reduce redeposition. The invention can solve the problems that the residual oxide on the copper surface and the co-adsorption residue thereof are difficult to remove efficiently under mild conditions, corrosion/defect is easy to cause when the copper surface is cleaned by strong acid and strong alkali, decontamination and low damage are difficult to be achieved by chemical or scrubbing alone.

Inventors

DENG ZHIHUA
CEN JIANYUN
LI XUEBO

Assignees

钜沣泰科技(东莞)有限公司

Dates

Publication Date: 20260508
Application Date: 20260131

Claims (9)

1. The chip cleaning agent is characterized by being an aqueous cleaning agent for cleaning the surface of a copper-containing chip after chemical mechanical planarization, and comprises a tartaric complexing agent and a pH adjusting component, wherein: The pH adjusting component is used for adjusting the chip cleaning agent to near-neutral working pH, wherein the near-neutral working pH is a pH range which enables the tartaric acid complexing agent to take deprotonated tartrate ions as main forms and realize copper oxide complexing dissolution and inhibit spontaneous dissolution of base copper under the condition of independent strong acid or strong alkali; The tartrate ions are configured to complex with copper ions dissolved or migrated to a liquid phase during the cleaning process to form soluble copper Tartaric acid complex to inhibit hydrolytic deposition of copper ion on the copper-containing chip surface and reduce secondary generation of copper oxide, complex dissolution reaction with copper oxide residue on the copper-containing chip surface to convert the copper oxide residue into soluble complex and take away from liquid phase, and the tartaric acid ion can be adsorbed on the copper-containing chip surface to form adsorption layer to inhibit excessive dissolution of base copper and reduce copper in cleaning process Redeposition of tartaric acid complex on the surface of the copper-containing chip.
2. The die cleaning agent of claim 1, wherein the tartaric acid-based complexing agent comprises tartaric acid, a racemate of tartaric acid, an enantiomer of tartaric acid, a tartrate salt, or a combination thereof, and the tartrate salt is selected from an ammonium salt, an alkali metal salt, an organic amine salt, or a combination thereof, such that the tartaric acid-based complexing agent provides a multidentate tartrate ion at the near neutral operating pH and forms a complex capable of stabilizing copper ions.
3. The die cleaner of claim 1, wherein the pH adjusting component is an alkaline adjusting component selected from the group consisting of ammonium hydroxide, ammonia, alkali metal hydroxides, alkali metal carbonates, buffer amines, or combinations thereof, the alkaline adjusting component being configured to adjust and maintain the pH of the die cleaner at the near neutral operating pH to maintain the tartrate ions in a deprotonated state and to continue to provide complexing capability for copper ions during cleaning.
4. The die cleaner of claim 1, wherein the die cleaner is configured to remove residues formed during chemical mechanical planarization and remaining on the surface of the copper-containing die, the residues including at least one of cuprous oxide and cupric oxide, and a surface complex or adsorption film co-adsorbed with at least one of the cuprous oxide and cupric oxide; The surface complex or the adsorption film comprises copper formed by a nitrogen-containing heterocyclic corrosion inhibitor Inhibitor complexes, copper formed from amino acid complexing agents Amino acid complexes, and combinations thereof, such that the chip cleaning agent synergistically carries away the surface complex or the adsorption film by preferentially complexing and dissolving at least one of the cuprous oxide and the cupric oxide, and reduces its surface shielding effect on subsequent processes.
5. The die cleaner of claim 1, wherein the die cleaner is used in conjunction with a brushing process that uses a polyvinyl alcohol brush or a porous elastomeric polymer brush to dynamically brush the copper-containing die surface to create localized hydrodynamic shearing and friction between bristles and the copper-containing die surface, under which the copper is brushed The tartaric acid complex and the adsorption layer exist in a weak adsorption state and are mechanically stripped and carried away with a liquid phase, so that the copper-containing chip surface has a residue removing effect in a brushing area and an adjacent area.
6. The production method of the chip cleaning agent is characterized in that the chip cleaning agent is an aqueous cleaning agent for cleaning the surface of a copper-containing chip after chemical mechanical planarization, and at least comprises a tartaric complexing agent and a pH adjusting component, and the production method comprises the following steps: Providing water as a solvent; Adding the tartaric acid-based complexing agent to the solvent and mixing to dissolve the tartaric acid-based complexing agent to obtain a tartaric acid-based solution; adding the pH adjusting component into the tartaric acid solution and adjusting to near-neutral working pH to enable the tartaric acid complexing agent to form a complexing system taking tartrate ions as a main form in the tartaric acid solution; purifying the adjusted solution to remove particles and insoluble matter; and sealing and packaging the purified solution to obtain the chip cleaning agent.
7. The method according to claim 6, wherein the water is deionized water, distilled water or water purified in a plurality of stages in the step of providing water as a solvent, the step of adding the tartaric acid-based complexing agent to the solvent and mixing comprises stirring, circulating mixing or ultrasonic dispersion until the tartaric acid-based complexing agent forms a uniform solution in the solvent, and the step of adding the pH-adjusting component and adjusting to the near neutral working pH comprises adding the pH-adjusting component in a gradual addition manner and synchronously monitoring pH changes so that the tartaric acid-based complexing agent in the obtained solution is mainly in the form of the tartrate ions and forms the complexing system.
8. The method of claim 6, wherein the purifying treatment comprises filtering to remove particles and insoluble materials, and wherein the filtering comprises at least one of membrane filtration, micro-pore filtration, or depth filtration to reduce secondary defects caused by particle contamination introduced during use of the chip cleaner.
9. The method of claim 6, wherein the hermetically packaging comprises packaging the chip cleaner in a clean environment in a sealed packaging container and marking, wherein the sealed packaging container is a polymeric material container or an inert metal material container chemically inert to the chip cleaner, and the marking comprises at least one of chemically mechanically planarizing the surface of the copper-containing chip with the chip cleaner and performing static immersion cleaning and dynamic brushing cleaning with a process.

Description

Chip cleaning agent and production method thereof Technical Field The invention relates to the technical field of cleaning agents, in particular to a chip cleaning agent and a production method thereof. Background In the chip copper interconnection process of an integrated circuit, post-cleaning after chemical mechanical planarization is used for removing copper surface residues to avoid affecting the reliability of subsequent processes and devices, the prior post-cleaning formulation and research are focused on removing abrasive particles and organic residues, copper oxide residues (and composite residues formed by co-adsorption of the copper oxide residues and organic inhibitors/complexing agents) which are easy to introduce or amplify and can induce secondary defects in the post-cleaning process are relatively insufficient, meanwhile, the synergism mechanism of mechanical brushing (such as a polyvinyl alcohol brush) and solution chemistry of the post-cleaning is complex, and the conventional electrochemical evaluation carried out only under a brushless condition is difficult to reflect the decontamination behavior and redeposition risk of a real brushing cleaning interface, so that deviation exists between formulation screening and mechanism judgment. Disclosure of Invention In view of the above technical problems, the invention provides a chip cleaning agent and a production method thereof, which aims to solve the problems that residual oxides on the surface of copper and co-adsorption residues thereof are difficult to remove efficiently under mild conditions, corrosion/defects are easy to cause in strong acid and alkali cleaning, decontamination and low damage are difficult to be achieved by chemical or scrubbing alone, and the like. Other features and advantages of the present disclosure will be apparent from the following detailed description, or may be learned in part by the practice of the disclosure. According to one aspect of the invention, a chip cleaning agent is provided, which is an aqueous cleaning agent for cleaning after the surface of a copper-containing chip after chemical mechanical planarization, and the chip cleaning agent comprises a tartaric complexing agent and a pH adjusting component, wherein: The pH adjusting component is used for adjusting the chip cleaning agent to near-neutral working pH, wherein the near-neutral working pH is a pH range which enables the tartaric acid complexing agent to take deprotonated tartrate ions as main forms and realize copper oxide complexing dissolution and inhibit spontaneous dissolution of base copper under the condition of independent strong acid or strong alkali; The tartrate ions are configured to complex with copper ions dissolved or migrated to a liquid phase during the cleaning process to form soluble copper Tartaric acid complex to inhibit hydrolytic deposition of copper ion on the copper-containing chip surface and reduce secondary generation of copper oxide, complex dissolution reaction with copper oxide residue on the copper-containing chip surface to convert the copper oxide residue into soluble complex and take away from liquid phase, and the tartaric acid ion can be adsorbed on the copper-containing chip surface to form adsorption layer to inhibit excessive dissolution of base copper and reduce copper in cleaning processRedeposition of tartaric acid complex on the surface of the copper-containing chip. Further, the tartaric acid-based complexing agent comprises tartaric acid, a racemate of tartaric acid, an enantiomer of tartaric acid, a tartrate salt, or a combination thereof, and the tartrate salt is selected from an ammonium salt, an alkali metal salt, an organic amine salt, or a combination thereof, such that the tartaric acid-based complexing agent provides a multidentate coordinated tartrate ion at the near neutral working pH and forms a complex capable of stabilizing copper ions. Further, the pH adjusting component is an alkaline adjusting component selected from ammonium hydroxide, ammonia, alkali metal hydroxide, alkali metal carbonate, buffer amine, or a combination thereof, which is used to adjust and maintain the pH of the chip cleaner at the near neutral working pH to keep the tartrate ions in a deprotonated state and to continue to provide complexing ability for copper ions during the cleaning process. Further, the chip cleaner is configured to remove residues formed during chemical mechanical planarization and remaining on the surface of the copper-containing chip, the residues including at least one of cuprous oxide and cupric oxide, and a surface complex or adsorption film co-adsorbed with at least one of the cuprous oxide and cupric oxide; The surface complex or the adsorption film comprises copper formed by a nitrogen-containing heterocyclic corrosion inhibitor Inhibitor complexes, copper formed from amino acid complexing agentsAmino acid complexes, and combinations thereof, such that the chip cleaning agent synerg