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CN-116575031-B - Titanium-tungsten corrosive liquid for integrated circuit and preparation method thereof

CN116575031BCN 116575031 BCN116575031 BCN 116575031BCN-116575031-B

Abstract

The invention provides a titanium-tungsten corrosive liquid for an integrated circuit and a preparation method thereof, which belong to the technical field of integrated circuits and are prepared from the following raw materials, by weight, 5-10 parts of nitric acid, 3-7 parts of sulfuric acid, 15-20 parts of phosphoric acid, 3-5 parts of polydopamine-chitosan complex stabilizer, 1-2 parts of surfactant and 40-50 parts of water. The titanium tungsten etching liquid for the integrated circuit can effectively etch the titanium tungsten alloy, effectively decompose the metal layer on the surface of the titanium tungsten, improve etching efficiency, and has uniform and thorough etching on the metal layer, stable performance and long service life, and residual liquid is easy to wash and has no residue after etching.

Inventors

  • GE YEMING
  • HE KE

Assignees

  • 江阴润玛电子材料股份有限公司

Dates

Publication Date
20260508
Application Date
20230228

Claims (10)

  1. 1. The titanium-tungsten corrosive liquid for the integrated circuit is characterized by comprising the following raw materials of nitric acid, sulfuric acid, phosphoric acid, polydopamine-chitosan complex stabilizer, surfactant and water; The polydopamine-chitosan complex stabilizer is prepared by dissolving chitosan in acid liquor, forming polydopamine-chitosan copolymer with dopamine hydrochloride under the action of a catalyst, and then under the action of hydrochloric acid.
  2. 2. The titanium-tungsten etching solution for integrated circuits according to claim 1, wherein the etching solution is prepared from, by weight, 5-10 parts of nitric acid, 3-7 parts of sulfuric acid, 15-20 parts of phosphoric acid, 3-5 parts of polydopamine-chitosan complex stabilizer, 1-2 parts of surfactant and 40-50 parts of water.
  3. 3. The titanium tungsten etching solution for integrated circuits according to claim 1, wherein the sulfuric acid is concentrated sulfuric acid having a concentration of more than 98%.
  4. 4. The titanium tungsten etching solution for an integrated circuit according to claim 1, wherein the surfactant is at least one selected from the group consisting of sodium dodecylbenzenesulfonate, sodium dodecylsulfonate, sodium dodecylsulfate, sodium tetradecylbenzenesulfonate, sodium hexadecylbenzenesulfonate, sodium hexadecylsulfonate, sodium hexadecylsulfate, sodium octadecylsulfonate, sodium octadecylbenzenesulfonate, and sodium octadecylsulfate.
  5. 5. The titanium-tungsten etching solution for integrated circuits according to claim 1, wherein the preparation method of the polydopamine-chitosan complex stabilizer is as follows: S1, dissolving chitosan in an acetic acid solution to obtain a chitosan solution; S2, adding dopamine hydrochloride and a catalyst into the chitosan solution prepared in the step S1, and heating and stirring for reaction to prepare a polydopamine-chitosan copolymer; S3, adding the polydopamine-chitosan copolymer prepared in the step S2 into hydrochloric acid, and stirring for reaction to prepare the polydopamine-chitosan complex stabilizer.
  6. 6. The titanium-tungsten etching solution for integrated circuits according to claim 5, wherein the concentration of the acetic acid solution in the step S1 is 3-5wt%, and the concentration of chitosan in the chitosan solution is 5-12wt%.
  7. 7. The titanium-tungsten etching solution for the integrated circuit according to claim 5, wherein the mass ratio of the chitosan solution to the dopamine hydrochloride to the catalyst in the step S2 is 100:15-20:2-3, the catalyst is Tris-HCl solution with the pH value of 5-6, the temperature of the heating and stirring reaction is 50-60 ℃, and the time is 1-2h.
  8. 8. The titanium-tungsten etching solution for integrated circuits according to claim 5, wherein the hydrochloric acid concentration in the step S3 is 2-4mol/L, and the stirring reaction time is 30-50min.
  9. 9. The titanium-tungsten etching solution for integrated circuits according to claim 5, wherein the preparation method of the polydopamine-chitosan complex stabilizer is specifically as follows: S1, dissolving chitosan in 3-5wt% of acetic acid solution to obtain 5-12wt% of chitosan solution; S2, adding 15-20 parts by weight of dopamine hydrochloride and 2-3 parts by weight of catalyst into 100 parts by weight of the chitosan solution prepared in the step S1, heating to 50-60 ℃, and stirring and reacting for 1-2 hours to prepare a polydopamine-chitosan copolymer; the catalyst is Tris-HCl solution with the pH value of 5-6; S3, adding the polydopamine-chitosan copolymer prepared in the step S2 into 2-4mol/L hydrochloric acid, and stirring and reacting for 30-50min to prepare the polydopamine-chitosan complex stabilizer.
  10. 10. A method for preparing the titanium-tungsten etching solution for the integrated circuit according to any one of claims 1 to 9, which is characterized by comprising the following steps of stirring and mixing nitric acid, sulfuric acid, phosphoric acid, a surfactant and water uniformly, adding a polydopamine complexing stabilizer, and stirring and mixing to prepare the titanium-tungsten etching solution for the integrated circuit.

Description

Titanium-tungsten corrosive liquid for integrated circuit and preparation method thereof Technical Field The invention relates to the technical field of integrated circuits, in particular to a titanium tungsten corrosive liquid for an integrated circuit and a preparation method thereof. Background With further scaling of chip feature sizes, the pitch of the on-chip input/output terminals has been advanced towards sub-100 micron dimensions (even up to 40 microns), which presents a significant challenge for the fabrication of bump structures on flip-chip packages, because photolithography and electroplating growth processes are industry standard process options for obtaining accurate bump size structures during the fabrication process of bump structures, and electroplated copper bump structures processes require a metal seed layer for electrical conduction. Because the surface electrode of the chip is usually made of aluminum (or aluminum-copper or aluminum-silicon), in order to avoid the mutual diffusion of aluminum and copper, a metal layer which can prevent the mutual diffusion of metal and ensure good connection between metals needs to be deposited on the surface of the aluminum electrode, and the metal layer is called a barrier layer in the industry, and the material is usually titanium-tungsten alloy and is usually formed by adopting a physical vapor deposition method. Wet etching methods are typically used to remove ineffective metallic titanium or titanium tungsten. Hydrogen peroxide is extremely susceptible to decomposition in the presence of copper ions, and therefore copper ion complexing agents and hydrogen peroxide stabilizers are required to be added. Because the tiny gaps on the surface of the titanium layer cause the phenomenon of uneven corrosion, a surfactant is added into the system, so that the surface tension of the corrosive liquid is reduced, the corrosive liquid can permeate into the tiny gaps, and the corrosion effect is improved. The titanium tungsten etchant composition is useful for selectively etching titanium tungsten alloys in the presence of at least one metal from the group consisting of copper, tin alloys, and aluminum. In addition, the existing corrosive liquid has the defect of unclean flushing, and the residual corrosive liquid can further corrode the chip, so that the existing corrosive liquid is further improved, and the improvement of the easy flushing property is also a technical problem which needs to be considered by a person skilled in the art. Disclosure of Invention The invention aims to provide a titanium-tungsten corrosive liquid for an integrated circuit and a preparation method thereof, which can effectively etch titanium-tungsten alloy, effectively decompose a metal layer on the surface of titanium-tungsten, improve etching efficiency, and have uniform and thorough corrosion on the metal layer, stable performance, long service life and no residue, and residual liquid is easy to wash after corrosion. The technical scheme of the invention is realized as follows: The invention provides a titanium-tungsten corrosive liquid for an integrated circuit, which comprises nitric acid, sulfuric acid, phosphoric acid, polydopamine-chitosan complex stabilizer, surfactant and water. The invention is further improved by the following raw materials, by weight, 5-10 parts of nitric acid, 3-7 parts of sulfuric acid, 15-20 parts of phosphoric acid, 3-5 parts of polydopamine-chitosan complex stabilizer, 1-2 parts of surfactant and 40-50 parts of water. As a further improvement of the invention, the sulfuric acid is concentrated sulfuric acid with a concentration of more than 98%. As a further improvement of the present invention, the surfactant is at least one selected from the group consisting of sodium dodecylbenzenesulfonate, sodium dodecylsulfonate, sodium dodecylsulfate, sodium tetradecylsulfonate, sodium tetradecylbenzenesulfonate, sodium hexadecylbenzenesulfonate, sodium hexadecylsulfate, sodium cetylsulfate, sodium octadecylsulfonate, sodium octadecylbenzenesulfonate, and sodium octadecylsulfate. As a further improvement of the invention, the preparation method of the polydopamine-chitosan complex stabilizer comprises the following steps: S1, dissolving chitosan in an acetic acid solution to obtain a chitosan solution; S2, adding dopamine hydrochloride and a catalyst into the chitosan solution prepared in the step S1, and heating and stirring for reaction to prepare a polydopamine-chitosan copolymer; S3, adding the polydopamine-chitosan copolymer prepared in the step S2 into hydrochloric acid, and stirring for reaction to prepare the polydopamine-chitosan complex stabilizer. As a further improvement of the invention, the concentration of the acetic acid solution in the step S1 is 3-5wt%, and the concentration of chitosan in the chitosan solution is 5-12wt%. As a further improvement of the invention, the mass ratio of the chitosan solution to the dopamine hydrochloride to