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CN-121733428-B - Reverse-dissolving open-pore polishing pad and preparation method and application thereof

CN121733428BCN 121733428 BCN121733428 BCN 121733428BCN-121733428-B

Abstract

The invention provides a reverse-soluble perforated polishing pad, a preparation method and application thereof, wherein the preparation method comprises the steps of immersing non-woven fabric base cloth in impregnating solution containing polyurethane resin to obtain the base cloth containing polyurethane resin, immersing the base cloth containing polyurethane resin in first solution for solidification treatment, cleaning the solidified base cloth by adopting second solution, and sequentially pre-drying, gradient drying and polishing the cleaned base cloth to obtain the polishing pad, wherein the first solution and the second solution are aqueous solutions containing DMF, the concentration of DMF in liquid extruded by the cleaned base cloth is 3-15 wt%, the pre-drying temperature is 80-100 ℃, and the gradient drying temperature is 130-180 ℃. The polishing pad prepared by the method has a loose and porous structure, has higher air permeability and conservation amount, has good polishing rate in the polishing process, and obviously improves the surface quality of the polished silicon wafer.

Inventors

  • GUO RUIXUAN
  • WANG HAIBO

Assignees

  • 上海映智研磨材料有限公司
  • 衢州博来纳润电子材料有限公司

Dates

Publication Date
20260512
Application Date
20260227

Claims (9)

  1. 1. A preparation method of a reverse-soluble perforated polishing pad is characterized by comprising the steps of immersing a non-woven fabric base fabric in an impregnating solution containing polyurethane resin to obtain the base fabric containing polyurethane resin, immersing the base fabric containing polyurethane resin in a first solution for solidification treatment, cleaning the solidified base fabric by adopting a second solution, sequentially predrying, gradient drying and polishing the cleaned base fabric to obtain the polishing pad, wherein the first solution and the second solution are aqueous solutions containing DMF, the concentration of DMF in the extruded liquid of the cleaned base fabric is 3-15 wt%, the predrying temperature is 80-100 ℃, the gradient drying temperature is 130-180 ℃, the first solution is an aqueous solution containing 10-30 wt% of DMF, the solidification treatment time is 10-40 min, and the second solution is an aqueous solution containing 3-15 wt% of DMF.
  2. 2. The preparation method of claim 1, wherein the solid content of the polyurethane resin in the impregnating solution is 10-30wt%; and/or the solvent of the impregnating solution is DMF; the polyurethane resin is thermoplastic polyurethane resin; and/or the molecular weight of the polyurethane resin is 10000-70000 Da; And/or the modulus of the polyurethane resin is 8-30 mpa; The polyurethane resin comprises a hard segment and a soft segment, wherein the hard segment is formed by reacting diisocyanate and a chain extender, the soft segment is formed by a polyol, the diisocyanate is any one or more selected from diphenylmethane diisocyanate, toluene diisocyanate, terephthalyl diisocyanate and naphthalene-1, 5-diisocyanate, the chain extender is any one or more selected from 1, 4-butanediol, ethylene glycol, hydroquinone-bis (2-hydroxyethyl) ether and hydroquinone dihydroxyethyl ether, and the polyol is any one or more selected from polytetramethylene glycol, polypropylene oxide, polyethylene oxide, polyadipic polyol, polycaprolactone and polycarbonate polyol.
  3. 3. The method according to claim 1, wherein the nonwoven fabric is a polyester fiber nonwoven fabric produced by a needle punching or a hydroentangling process; and/or the fiber fineness of the non-woven fabric is 2-10 dtex; And/or the fiber length of the non-woven fabric is 30-80 mm; And/or the thickness of the non-woven fabric is 1.8-2.2 mm; And/or the gram weight of the non-woven fabric is 250-330 g/m 2 .
  4. 4. The method of claim 1, further comprising squeezing the base fabric after soaking to remove excess impregnating solution; and/or the mass ratio of polyurethane resin solid to non-woven fabric base cloth in the impregnating solution is 1-3:1.
  5. 5. The preparation method of claim 1, wherein the pre-drying time is 10-30 min; And/or the content of water in the base fabric after pre-drying is 0-10wt%.
  6. 6. The preparation method of claim 1, wherein the gradient drying time is 20-60 min; and/or the DMF content in the base cloth after gradient drying is 0wt%.
  7. 7. A counter-soluble open-cell polishing pad obtained by the method of any one of claims 1 to 6.
  8. 8. The polishing pad according to claim 7, wherein a mass ratio of the nonwoven fabric to the polyurethane resin in the polishing pad is 1-2:3-4; and/or the air permeability of the polishing pad is 200-700L/M 2 /S; and/or the amount of conservation of the polishing pad is 100-500 mg/cm 3 .
  9. 9. Use of the counter-soluble open-cell polishing pad obtained by the production method according to any one of claims 1 to 6 and/or the counter-soluble open-cell polishing pad according to any one of claims 7 to 8 in polishing a silicon substrate.

Description

Reverse-dissolving open-pore polishing pad and preparation method and application thereof Technical Field The invention relates to the technical field of polishing pad preparation, in particular to a reverse-dissolving open-pore polishing pad, and a preparation method and application thereof. Background Polishing pads, which are one of the core consumables in Chemical Mechanical Planarization (CMP) processes, have properties directly related to global planarization of the wafer surface, defect control levels, and process stability. Polishing pads are typically prepared from porous polymeric materials (e.g., polyurethane) by a specific process and have the core function of storing and uniformly delivering the polishing fluid, providing moderate mechanical friction, timely removal of reaction byproducts and swarf, while maintaining a stable polishing interface environment. Thus, the microstructure design of the polishing pad, and in particular its pore characteristics (e.g., porosity, pore size distribution, pore connectivity), has a decisive influence on polishing performance. Among the performance parameters of the polishing pad, air permeability and the amount of conservation are two key and interrelated indicators. The air permeability mainly reflects connectivity of pores in the polishing pad and gas passing capacity, and the high air permeability is beneficial to rapid discharge of heat, gas and fine debris generated in the polishing process, so that defects such as scratch and residue on the surface of a wafer are reduced, and process stability and wafer surface quality are improved. The self-conservation amount refers to the capability of the polishing pad to store and maintain the polishing liquid, and the high self-conservation amount can ensure that the surface of the polishing pad continuously and stably supplies the fresh polishing liquid to the polishing interface in the high-speed polishing process, and the uniformity and the high efficiency of the chemical reaction are maintained, so that the method is important for obtaining uniform material removal rate, reducing corrosion and realizing excellent planarization effect. Currently, polishing pads (e.g., consolidated porous polyurethane pads) that are widely used in the industry are introduced into the pores mainly by means of foaming processes, filler porosification, or machining. However, under the prior art conditions, the air permeability and the conservation amount of the polishing pad often show a significant negative correlation or an inherent contradiction that is difficult to optimize simultaneously, which becomes a technical bottleneck that restricts the performance of the high-end CMP process (particularly for polishing advanced process node wafers) from further improving. Therefore, how to break through the limitations of the existing polishing pad materials and structures, develop an innovative preparation method to enable the polishing pad materials to be cooperatively optimized and simultaneously obtain a polishing pad with high air permeability and high conservation, so that in the polishing process, not only can sufficient and stable polishing liquid supply be ensured to realize uniform material removal, but also good heat dissipation and chip removal capability can be ensured to obtain a defect-free high-quality wafer surface, and the key technical problem to be solved by the person in the field is urgent. Disclosure of Invention In view of the above-mentioned drawbacks of the prior art, an object of the present invention is to provide a reversely-soluble open-pore polishing pad, and a preparation method and use thereof, for solving the problem that the polishing pad in the prior art cannot achieve both high air permeability and high conservation. To achieve the above and other related objects, the present invention provides a counter-dissolving open-cell polishing pad, and a method for preparing and using the same. The invention provides a preparation method of a reverse-soluble open-pore polishing pad, which comprises the steps of immersing non-woven fabric base cloth in impregnating solution containing polyurethane resin to obtain the base cloth containing polyurethane resin, immersing the base cloth containing polyurethane resin in first solution for solidification treatment, cleaning the solidified base cloth by adopting second solution, and sequentially pre-drying, gradient drying and polishing the cleaned base cloth to obtain the polishing pad, wherein the first solution and the second solution are aqueous solutions containing DMF, the concentration of DMF in liquid extruded by the cleaned base cloth is 3-15 wt%, the pre-drying temperature is 80-100 ℃, and the gradient drying temperature is 130-180 ℃. Preferably, the solid content of the polyurethane resin in the impregnating solution is 10-30wt%, and for example, 10wt%, 15wt%, 20wt%, 25wt% and 30wt%. Preferably, the solvent of the impregnating solution is DMF. Further p