End point detection method applying resonance phenomenon, end point detection apparatus, chemical mechanical polishing apparatus on which the detection apparatus is loaded, and semiconductor device fabricated by the chemical mechanical polishing apparatus

Abstract

To provide an end point detection method applying a resonance phenomenon, an end point detection apparatus, and a chemical mechanical polishing apparatus on which the detection apparatus is loaded for monitoring variation in the thickness of an electrically conductive film in real time, reliably detecting a polishing end point of the electrically conductive film at high accuracy, without generating noise, low power consumption, and capable of reducing the cost.

In order to achieve above described objects, the present invention provides an end point detection method applying a resonance phenomenon in which a polishing end point is detected when the electrically conductive film is polished and removed to an appropriate thickness, wherein a sensor 37 composed of an oscillation circuit of the Colpitts type or the like having a planar inductor and a concentrated constant capacitor is used, and the variation in the thickness of the electrically conductive film is monitored in real time from the variation in the oscillation frequency of the sensor 37 caused along with the variation in the thickness of the electrically conductive film opposed to the planar inductor.

Description

FIELD OF THE INVENTION[0001]The present invention relates to an end point detection method applying a resonance phenomenon, an end point detection apparatus, a chemical mechanical polishing apparatus on which the detection apparatus is loaded, and a semiconductor device fabricated by the chemical mechanical polishing apparatus, and particularly relates to an end point detection method applying the resonance phenomenon capable of reliably detecting a polishing end point of an electrically conductive film at high accuracy in chemical mechanical polishing processing (CMP), an end point detection apparatus, a chemical mechanical polishing apparatus on which the detection apparatus is loaded, and a semiconductor device fabricated by the chemical mechanical polishing apparatus.BACKGROUND OF THE INVENTION[0002]As a conventional art related to an end point detection method applying the resonance phenomenon, an end point detection apparatus, and a chemical mechanical polishing apparatus on w...

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Benefits of technology

[0056]In the invention according to claim 10, the variation in the oscillation frequency of the sensor caused along with the variation in the thickness of the electrically conductive film is not monotonous increase or decrease but has a peak, and the polishing is stopped by using either a point at which the peak is detected or a point at which a predetermined amount of polishing is performed after the peak is detected as a polishing end point depending on the film type of the electrically conductive film; therefore, there is an advantage that appropriate polishing end points can be appropriately obtained respectively for the electrically conductive films having different film types since the peaks of the oscillation frequencies from the sensor appears as a rapid form or a gentle form depending on the film type of the electrically conductive film.

[0057]In the invention according to claim 11, the variation in the oscillation frequency of the sensor caused along with the variation in the thickness of the electrically conductive film is not monotonous increase or decrease but has a peak, and the film thickness at which the peak appears is constant; therefore, a threshold value is set based on the peak, and the point at which the oscillation frequency reaches the threshold value before or after the peak is set as a polishing end point; thus, there is an advantage that excessive polishing or insufficiency in the polishing amount can be prevented.

[0058]In the invention according to claim 12, the electrically conductive film is formed on a surface of a wafer, and the planar inductor is in the vicinity of either the electrically conductive film of the wafer surface portion or the back surface of the wafer; therefore, in both the case in which the planar inductor is opposed to the electrically conductive film without the intermediation of the wafer and the case in which the planar inductor is opposed to the electrically conductive film via the wafer, the variation in the thickness of the electrically conductive film can be monitored in real time, and the polishing end point at which the electrically conductive film is polished and removed to an appropriate thickness can be detected. Therefore, there is an advantage that the sensor can be embedded in either the upper surface portion of the platen constituting the chemical mechanical polishing apparatus or in the polishing head.

[0059]The invention according to claim 13 is an end point detection apparatus which executes the end point detection method applying the resonance phenomenon according t...

Problems solved by technology

Secondly, the planar inductor gen...

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