Process for preventing diamond scratch in process of CMP

Abstract

The invention provides a method for preventing diamond scratching during the CMP process. The method is as follows: firstly, alkaline solution with adequate concentration is splashed after the CMP polishing process so as to neutralize acid polishing slurry which is left on a polishing pad after the polishing process; secondly, finishing of the polishing pad is performed by utilization of a diamond finishing device. Therefore, erosion of the acid polishing slurry on the diamond finishing device is effectively avoided and the possibility of falling off of diamond particles of the diamond finishing device is further reduced, so that wafers for performing CMP technique subsequently can avoid generation of diamond scratching.

Description

technical field [0001] The invention relates to a method for preventing diamond scratches from being generated during CMP, in particular to a method for preventing diamond scratches from being generated during CMP by utilizing an alkaline solution. Background technique [0002] Polishing involves contacting the surface of an object with a polishing pad, and performing relative motion to generate friction, thereby depleting the surface components of the object. Since the pressure is concentrated on the protruding part of the surface, the material loss rate there is relatively fast, so after a period of time, the surface of the object can have the effect of planarization. After the polishing pad is used for a period of time, the characteristics will deteriorate, so a polishing finisher is often needed to remove the polishing residues in the fine pores on the polishing pad, so as to make the polishing meet the requirements of repeatability and stability. . [0003] However, i...

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Problems solved by technology

[0003] However, in the CMP process of tungsten, the polishing pad and the acidic polishing slurry composed of potassium ferricyanide, ferric nitrate, potassium iodate and hydrogen peroxide are mainly used to simultaneously perform chemical reaction and mechanical polishing. and other double processing actions to planarize the surface of the wafer, but the corrosive polishing slurry will corrode the metal base of the polishing finisher that subsequently cleans the surface of the polishing pad, resulting in the appearance of the polishing finisher being similar to that of diamonds. The loss of abrasive grains, moreover, the diamonds dropped on the polishing pad due to corrosion will cause scratches on the surface of the subsequent polished wafer

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