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CN-122007991-A - Coarse-fine cooperative grinding surface repairing method of DFG 8560 biaxial system for 12-inch wafer

CN122007991ACN 122007991 ACN122007991 ACN 122007991ACN-122007991-A

Abstract

The application belongs to the technical field of semiconductor manufacturing equipment and processes, and particularly relates to a rough-fine collaborative grinding surface repairing method of a DFG 8560 double-shaft system for a 12-inch wafer. The method aims to solve the problems of low efficiency, deep subsurface damage and errors caused by repeated clamping of the traditional single-shaft grinding. The method comprises the steps of carrying out rough grinding on a first main shaft of a DFG 8560 double-shaft system by adopting a resin-bonded diamond grinding wheel, efficiently removing materials and controlling the depth of a damaged layer, carrying out fine grinding on a second main shaft by adopting a ceramic-bonded diamond grinding wheel, precisely stripping the damaged layer, and finally eliminating elastic deformation through polishing treatment to obtain a nanoscale flat surface. The whole process is completed by once clamping, and parameters are independently regulated and controlled by double shafts, so that high efficiency, low damage and high uniformity are realized. The method obviously improves the processing efficiency, reduces the depth of surface damage and the comprehensive cost, and has strong process adaptability and compatibility.

Inventors

  • Wan Mengjia
  • Han Wujing

Assignees

  • 安徽富乐德长江半导体材料股份有限公司

Dates

Publication Date
20260512
Application Date
20260228

Claims (8)

  1. 1. A rough-fine cooperative grinding surface repairing method of a DFG 8560 double-shaft system for a 12-inch wafer is characterized by comprising the following steps of 1, performing rough grinding treatment, mounting a resin-bonded diamond grinding wheel on a1 st main shaft of the DFG 8560 double-shaft grinding system, performing efficient material removal on the surface of the clamped and positioned wafer, controlling the single removal amount to be enough to cover the range of heavy scratch and typical depth of complex film residue, wherein the rotating speed of the 1 st main shaft is 1500-2000rpm, the rotating speed of a table is 1800-2200rpm, and controlling the single removal amount of rough grinding to be 8-12 mu m; step 2, performing fine grinding treatment, namely mounting a ceramic-bonded diamond grinding wheel on a2 nd spindle of a DFG 8560 double-spindle grinding system, performing micron-level precise trimming on the surface of the wafer after coarse grinding, controlling the single removal amount of fine grinding to be 3-5 mu m, setting the spindle rotating speed of the 2 nd spindle to be 2000-2500 rpm, setting the rotating speed of a table to be 2200-2400 rpm rpm, and stripping microcracks and plastic deformation areas generated in the coarse grinding stage layer by increasing the effective grinding path density and stable pressure distribution until a complete and nondestructive crystal material body is exposed; And 3, performing polishing treatment, namely maintaining the rotating speeds of the 2 nd spindle and the table plate at the end of the fine grinding circulation, stopping feeding movement, rubbing for 3 to 5 minutes in a zero feeding state, controlling the interfacial temperature rising rate in the polishing process to be less than or equal to 0.5 ℃ per minute, and finally enabling the surface roughness Ra to be less than or equal to 0.8nm.
  2. 2. The method for repairing the rough-fine co-grinding surface of the DFG 8560 biaxial system for a 12-inch wafer according to claim 1, wherein the bonding agent of the resin bonded diamond grinding wheel adopted in the step 1 is composed of a phenolic resin matrix, has moderate elastic modulus and thermal stability, can maintain the self-sharpening property of abrasive particles under a medium load, and avoids wafer fragments caused by cutting force increase due to excessive passivation of the abrasive particles.
  3. 3. The method for repairing a rough-fine co-grinding surface of a DFG 8560 dual-axis system for a 12-inch wafer according to claim 1, wherein the single removal amount is controlled to be 8 to 12 μm in step 1, the range covers heavy scratch defects with a depth of 3 μm or more and a length of 50 μm or more, and complex film residues with a film thickness of 1 μm or more and a coverage area of 20% or more.
  4. 4. The method for repairing the rough-fine co-grinding surface of the DFG 8560 biaxial system for the 12-inch wafer according to claim 1, wherein the bonding agent of the ceramic bonded diamond grinding wheel adopted in the step 2 is composed of sintered alumina-silica composite ceramic, has compact structure and high hardness, can maintain the geometric stability of superfine abrasive particles in long-time micro-cutting, and ensures the consistency of surface roughness.
  5. 5. The method for repairing a rough-finish co-grinding surface of a DFG 8560 biaxial system for a12 inch wafer according to claim 1, wherein the single removal rate is controlled to be 3 to 5 μm in step 2, and the value is precisely matched with the depth of the subsurface damage layer introduced in the rough grinding stage, so as to ensure complete removal of the damaged area without causing additional material waste, while reserving the minimum necessary removal margin for the subsequent chemical mechanical polishing.
  6. 6. The method for repairing the rough-fine co-grinding surface of the DFG 8560 biaxial system for a 12-inch wafer according to claim 1, wherein the polishing treatment time in the step 3 is 3 to 5 minutes, the time period enables the interface between the wafer and the grinding wheel to reach a thermal-force balance state, accumulated elastic strain energy is effectively released, surface waviness and local protrusions are remarkably reduced, and the final surface roughness Ra value is stably controlled below 0.8 nm.
  7. 7. The method for repairing the rough-fine co-grinding surface of the DFG 8560 biaxial system for the 12-inch wafer according to claim 1, wherein the rough grinding and fine grinding processes are continuously completed in the DFG 8560 biaxial system under one clamping without unloading or realignment in the middle, so that the rough grinding reference surface and the fine grinding processing surface are ensured to be strictly coplanar, and the uniformity of the whole thickness is improved.
  8. 8. The method for repairing the rough-fine collaborative grinding surface of the DFG 8560 double-shaft system for the 12-inch wafer according to claim 1, wherein the DFG 8560 double-shaft system respectively and independently regulates and controls the rotation speed of a main shaft, the rotation speed of a table disc and the feeding rate in the rough grinding stage and the fine grinding stage, realizes dynamic decoupling and accurate matching of process parameters, and avoids performance compromise between high removal and low damage targets of a single shaft system.

Description

Coarse-fine cooperative grinding surface repairing method of DFG 8560 biaxial system for 12-inch wafer Technical Field The application belongs to the technical field of semiconductor manufacturing equipment and processes, and particularly relates to a rough-fine collaborative grinding surface repairing method of a DFG 8560 double-shaft system for a 12-inch wafer. Background In the 12 inch recycling wafer manufacturing process, surface repair is a key link for determining the wafer recycling value and the device yield. The current main flow process faces two major contradictions, namely, firstly, a high-mesh grinding wheel (more than 6000 meshes) can realize extremely low surface damage and high consistency, but has low material removal rate, and is difficult to effectively treat serious defects such as deep scratches or complex film residues, and secondly, a single-shaft accurate grinding mode has high precision, but depends on the whole process operation of the high-mesh grinding wheel, so that the processing period is long, the productivity is low, the grinding wheel abrasion is high, the adaptability to wafers with heavy initial damage is poor, and the large-scale high-efficiency production requirement is difficult to meet. Therefore, a synergistic polishing strategy that combines high efficiency with high surface quality is needed. Through searching, a polishing method of a wafer with the publication number of CN103394994B is disclosed, and the publication date is 2017, 12, 15. The patent adopts a single polishing disc staged polishing strategy, and controls the endpoint through high-medium-low pressure combination and on-line monitoring, so as to reduce residues and corrosion. However, the scheme is still limited to single shafting operation, a rough grinding pretreatment link is not introduced, high removal amount scenes such as deep scratch or thick film residues cannot be effectively treated, the whole process of the scheme depends on Chemical Mechanical Polishing (CMP), the capability of repairing serious surface defects is limited, the stress distribution and the material removal uniformity of a 12-inch large-size wafer in a biaxial system are not optimized, and high-efficiency rough-fine coordination is difficult to realize. Through searching, a method for repairing a fog surface damage layer of a 12-inch wafer with the publication number of CN120565401A is disclosed, and the publication date is 2025, 8, and 29 (substantial inspection stage). The patent proposes the use of a multistage energy regulated surface repair device to reduce roughness from 50-60nm to below 5nm by precisely controlling the energy density of the stream to remove the defogging-surface damage layer. However, the method relies on non-contact energy injection (such as plasma or particle beam), belongs to a physical/chemical composite repair means and is not based on a mechanical grinding path, and does not relate to structural adaptation of a DFG 8560 dual-shaft grinding platform, and does not construct cooperative process logic of coarse grinding rapid damage removal and fine grinding high-quality ending, so that fundamental contradiction between high removal rate and low surface damage cannot be solved, and equipment universality and product line integration are doubtful. The above problems indicate that the prior art is limited to either single axis low efficiency lapping or non-lapping type repair techniques, lacking a rough-finish co-lapping mechanism for a 12 inch wafer, adapted to a DFG 8560 dual axis system. Therefore, the invention provides a rough-fine collaborative grinding surface repairing method of a DFG 8560 double-shaft system for a 12-inch wafer, which realizes high-efficiency and high-quality repairing of complex defects such as deep scratches, film residues and the like by double-shaft division (high removal of single-shaft rough grinding and low damage of single-shaft fine grinding), dynamic matching of technological parameters and thermal-force coupling control, obviously improves the output efficiency and the surface quality of a regenerated wafer, and meets the severe requirements of a first-pass process on the regenerated wafer. Disclosure of Invention The invention aims to provide a wafer-oriented rough-fine collaborative grinding surface repairing method of a DFG 8560 biaxial system, which can effectively solve the problems in the background technology. In order to achieve the above purpose, the technical scheme adopted by the invention is as follows: 1. a rough-fine cooperative grinding surface repairing method of a DFG 8560 double-shaft system for a 12-inch wafer is characterized by comprising the following steps of 1, performing rough grinding treatment, mounting a resin-bonded diamond grinding wheel on a1 st main shaft of the DFG 8560 double-shaft grinding system, performing efficient material removal on the surface of the clamped and positioned wafer, controlling the single removal amount to be e