METHOD OF END-POINT DETECTION UTILIZING CHEMICAL REACTION

    公开(公告)号:JP2000031102A

    公开(公告)日:2000-01-28

    申请号:JP11778999

    申请日:1999-04-26

    Applicant: IBM

    Abstract: PROBLEM TO BE SOLVED: To detect end point for a target film lying on a stopper film by monitoring a reaction product during removal of the target film with a process that generates the chemical-reaction product from either the stopper film or the target film. SOLUTION: A target film is removed by a process that generates a chemical- reaction product selectively from a stopper film or from the target film. Namely, in chemical-mechanical polishing of a substrate 100 on which a target film 104 of an oxide (SiO2) lies on a stopper film 102 of a nitride (Si3N4) with slurry (mixture of micro-silica, water, and KOH), ammonium (NH3) is generated by a chemical reaction when the removal reaches the boundary 106. The level change of the ammonium in the slurry indicates that the removal reaches the underlying nitride film, and consequently, by monitoring the level of ammonium in the slurry, end point of the oxide film removal can be judged. When the end point is reached, the polishing is stopped.

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