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CN-121973103-A - Method for synchronously detecting cutting rate of trimmer and roughness of polishing pad

CN121973103ACN 121973103 ACN121973103 ACN 121973103ACN-121973103-A

Abstract

The invention belongs to the field of wafer manufacturing, and relates to a method for synchronously detecting the cutting rate of a trimmer and the roughness of a polishing pad, which comprises the following steps of (1) selecting the polishing pad with a groove, and measuring the initial groove depth of the polishing pad by adopting a depth gauge; the method comprises the steps of (1) polishing a polishing pad by using a trimmer, stopping operation at intervals in the polishing process, measuring the groove depth of the polishing pad by using a depth gauge again, and measuring the surface roughness of the polishing pad by using a roughness meter, and (3) calculating the cutting rate of the trimmer according to the groove depth variation of the polishing pad and the corresponding polishing time to finish synchronous detection of the cutting rate of the trimmer and the roughness of the polishing pad. The method provided by the invention realizes synchronous detection of the cutting rate of the trimmer and the roughness of the polishing pad, and provides unified factory inspection standard and abnormal use analysis basis for the trimmer.

Inventors

  • WANG ZI
  • ZHENG RUILIN

Assignees

  • 沐科恒益(江苏)电子制造有限责任公司

Dates

Publication Date
20260505
Application Date
20260316

Claims (10)

  1. 1. A method for simultaneously detecting a conditioner cut rate and a polishing pad roughness, the method comprising the steps of: (1) Selecting a polishing pad with a groove, and measuring the initial groove depth of the polishing pad by adopting a depth gauge; (2) Polishing the polishing pad by using a trimmer, stopping operation at intervals in the polishing process, measuring the groove depth of the polishing pad by using a depth gauge again, and measuring the surface roughness of the polishing pad by using a roughness meter; (3) And calculating the cutting rate of the trimmer according to the groove depth variation of the polishing pad and the corresponding polishing time, and finishing synchronous detection of the cutting rate of the trimmer and the roughness of the polishing pad.
  2. 2. The method for synchronously detecting a cutting rate of a conditioner and a roughness of a polishing pad according to claim 1, wherein the groove type of the polishing pad in step (1) comprises a cross-shaped groove and/or a concentric groove, preferably a cross-shaped groove.
  3. 3. The method for synchronously detecting the cutting rate of a trimmer and the roughness of a polishing pad according to claim 1, wherein the initial trench depth in the step (1) has 2 to 20 measurement points; and/or, the measurement points of the initial groove depth in the step (1) are uniformly distributed on the surface of the polishing pad.
  4. 4. A method for synchronously detecting a cutting rate of a dresser and a roughness of a polishing pad according to any one of claims 1 to 3, wherein the polishing liquid used in the polishing treatment in the step (2) comprises deionized water; and/or, the liquid supply rate of the polishing treatment in the step (2) is 50-150 mL/min.
  5. 5. The method for synchronously detecting the cutting rate of the trimmer and the roughness of the polishing pad according to any one of claims 1 to 3, wherein in the polishing process in the step (2), the applying pressure of the trimmer to the polishing pad is 2 to 15lbs; and/or, in the polishing process in the step (2), the trimmer is in a rotating state and swings reciprocally along a preset track; The rotating speed of the trimmer is 50-100 rpm, and the reciprocating swing stroke range is 60-80 mm.
  6. 6. The method for synchronously detecting a dressing cut rate and a polishing pad roughness of claim 5, wherein during the polishing of step (2), the polishing pad is rotated in the same or opposite direction as the dressing; wherein the rotation speed of the polishing pad is 80-150 rpm.
  7. 7. The method for synchronously detecting the cutting rate of the trimmer and the roughness of the polishing pad according to any one of claims 1 to 3, wherein in the polishing process in the step (2), the operation is stopped 1 time every 5 to 15min, and the number of times of the operation stopping at intervals is not less than 3.
  8. 8. The method for synchronously detecting a cutting rate of a conditioner and a roughness of a polishing pad according to any one of claims 1 to 3, wherein the cutting rate of the conditioner in the step (3) is a groove depth variation of the polishing pad divided by a corresponding polishing time; The change amount of the groove depth of the polishing pad is the difference between the initial groove depth of the polishing pad and the groove depth after polishing.
  9. 9. The method for synchronously detecting the cutting rate of the trimmer and the roughness of the polishing pad according to any one of claims 1 to 3, wherein the number of the trimmers in the step (2) is 2, and the polishing pad is polished by synchronously controlling the 2 trimmers.
  10. 10. The method for synchronously detecting the cutting rate of the trimmer and the roughness of the polishing pad according to any one of claims 1 to 3, wherein in the polishing process in the step (2), the running-in process is synchronously performed on the trimmer, and the grains of the surface of the trimmer, which are not sintered firmly, are cut down by polishing.

Description

Method for synchronously detecting cutting rate of trimmer and roughness of polishing pad Technical Field The invention belongs to the field of wafer manufacturing, and relates to a method for synchronously detecting the cutting rate of a trimmer and the roughness of a polishing pad. Background Chemical Mechanical Polishing (CMP) is a critical process in semiconductor manufacturing to achieve global planarization of wafers, with polishing accuracy directly determining the degree of integration and reliability of wafer devices. The polishing pad conditioner (Diamond Disk) is used as an important consumable material for the CMP process, plays a key role in removing the glazing layer of the polishing pad, recovering the surface roughness and the groove structure and guaranteeing the stable polishing rate, and has the performance advantages and disadvantages which are highly related to the yield and the efficiency of wafer production. Along with the evolution of the semiconductor process to nano-scale and super-nano-scale and the application of the multi-element metal interconnection materials such as copper, cobalt, ruthenium and the like, strict requirements are put on the nano-scale morphology control, dynamic cutting stability and cross-material trimming compatibility of the trimmer in the industry. However, in the existing preparation and application links of the trimmer, a plurality of technical short plates still exist, and the performance defect of the short plates becomes an important factor for restricting the improvement of the precision of the CMP process. In the aspect of diamond preparation and arrangement, the existing technology has insufficient sorting precision of diamond particles, natural differences exist in particle size and shape, and the process deviation of coating and sintering technology causes the difference in height of diamond on a surface of a trimmer, even tens of microns, and only a few high particles contact a polishing pad in the initial period of trimming, so that uneven polishing pressure distribution is caused, the wafer removal rate is quickly attenuated, and planarization consistency is seriously affected. In addition, on the combination level of the substrate and the interface, the main stream metal substrate (such as stainless steel) is easy to corrode in an acidic/alkaline polishing solution system of CMP, so that the bonding force between diamond and the substrate is attenuated, the interface layer formed by electroplating or brazing is easy to cause electrochemical corrosion, the diamond threshing is accelerated, the service life of the trimmer is greatly shortened, meanwhile, the flatness and the dimensional tolerance control difficulty of the substrate processing are high, the performance fluctuation among batches is obvious, the abrasion rate of a polishing pad is inconsistent, and the stability of the wafer removal rate is further influenced. In the actual dressing process, the fallen diamond particles and metal scraps are easy to remain on the surface of the polishing pad, so that the diamond particles and metal scraps become a main defect source of wafer micro scratches, the tolerance of advanced processes with the wavelength of 5nm and below to defects is almost zero, and the pollution directly causes the reduction of wafer yield. If the abrasion scraps are difficult to discharge in time, micropores and grooves of the polishing pad are easy to block, so that the polishing liquid is unevenly distributed, and the polishing efficiency and the quality stability are further reduced. More importantly, the existing semiconductor industry is not perfect aiming at the detection system of the performance of the trimmer, lacks a standardized detection method capable of accurately quantifying the cutting rate of the trimmer to the polishing pad, does not have unified factory inspection indexes and abnormal use analysis basis, is mainly used for off-line sampling inspection, can only judge partial appearance indexes, cannot pre-judge the cutting uniformity of the trimmer in actual use, and meanwhile, has no integrated detection means in the industry to realize synchronous detection of the cutting rate and the surface roughness of the polishing pad. Therefore, the performance defect of the above-mentioned trimmer and the technical blank of the inspection system together lead to the fact that the trimmer cannot fully function in the CMP process, and the yield and the cost management of wafer production face serious challenges, which need to be solved by a targeted technical means. Disclosure of Invention Aiming at the defects existing in the prior art, the invention aims to provide a method for synchronously detecting the cutting rate of a trimmer and the roughness of a polishing pad, so as to realize synchronous detection of the cutting rate of the trimmer and the roughness of the polishing pad and provide unified factory inspection standard and abnormal use analysis basis