| 摘要 |
The present invention provides an electrochemical polishing method capable of increasing a polishing speed while preventing excessive polishing, such as dishing or erosion. In the electrochemical polishing method, when a voltage applied to a conductive film formed on the surface of a substrate is increased at a contact surface pressure of 0 between the surface of the substrate and a polishing pad, a voltage at a first change point C that allows a current density to start to decrease after an increase is referred to as a minimum voltage. In addition, when the voltage is increased at a contact surface pressure having a finite value, a voltage at a second change point B that allows the current density to be maintained constant after the decrease is referred to as a maximum voltage. In this case, the surface of the conductive film is polished while maintaining the voltage to be not lower than the minimum voltage and not higher than the maximum voltage. Further, the present invention provides an electrochemical polishing method capable of rapidly removing a conductive film in regions other than a contact plug or wiring line forming region while preventing excessive polishing, such as dishing or erosion. In the electrochemical polishing method, in a step of increasing a voltage, when the voltage is increased at a contact surface pressure of 0, a voltage at a first change point C that allows a current density to start to decrease after an increase is referred to as a threshold voltage, and the voltage is increased such that a voltage in a region in which a barrier film is exposed is higher than the threshold voltage.
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