Eddy current sensor
First Claim
1. An eddy current sensor comprising:
- a sensor coil disposed near a conductive film formed on a substrate;
a signal source configured to supply an AC signal to said sensor coil to produce an eddy current in the conductive film;
a detection circuit operable to detect the eddy current produced in the conductive film, said detection circuit being connected to said sensor coil; and
a housing made of a material having a high magnetic permeability, said housing accommodating said sensor coil therein.
1 Assignment
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Accused Products
Abstract
An eddy current sensor (10) has a sensor coil (100) disposed near a conductive film (6) formed on a semiconductor wafer (W) and a signal source (124) configured to supply an AC signal to the sensor coil (100) to produce an eddy current in the conductive film (6). The eddy current sensor (10) includes a detection circuit operable to detect the eddy current produced in the conductive film (6). The detection circuit is connected to the sensor coil (100). The eddy current sensor (10) also includes a housing (200) made of a material having a high magnetic permeability. The housing (200) accommodates the sensor coil (100) therein. The housing (200) is configured so that the sensor coil (100) forms a path of a magnetic flux (MF) so as to effectively produce an eddy current in the conductive film (6).
70 Citations
29 Claims
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1. An eddy current sensor comprising:
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a sensor coil disposed near a conductive film formed on a substrate;
a signal source configured to supply an AC signal to said sensor coil to produce an eddy current in the conductive film;
a detection circuit operable to detect the eddy current produced in the conductive film, said detection circuit being connected to said sensor coil; and
a housing made of a material having a high magnetic permeability, said housing accommodating said sensor coil therein. - View Dependent Claims (2, 3, 4, 5, 27, 28, 29)
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6. An eddy current sensor comprising:
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a sensor coil disposed near a conductive film formed on a substrate;
a signal source configured to supply an AC signal to said sensor coil to produce an eddy current in the conductive film;
a detection circuit operable to detect the eddy current produced in the conductive film, said detection circuit being connected to said sensor coil; and
an insulating member accommodating said sensor coil therein, said insulating member being embedded in a conductive material.
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7. An eddy current sensor comprising:
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a sensor coil disposed near a conductive film formed on a substrate;
a signal source configured to supply an AC signal to said sensor coil to produce an eddy current in the conductive film;
a detection circuit operable to detect the eddy current produced in the conductive film based on an impedance as viewed from said sensor coil; and
a controller configured to specify a point including a resistance component and a reactance component of the impedance in rectangular coordinates and to detect film thickness of the conductive film from an angle formed by a line connected between the point and the a predetermined central point in the rectangular coordinates. - View Dependent Claims (8, 9)
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10. An eddy current sensor comprising:
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a sensor coil disposed near a first conductive film formed on a substrate;
a signal source configured to supply an AC signal to said sensor coil to produce an eddy current in the first conductive film;
a detection circuit operable to detect the eddy current produced in the first conductive film based on an impedance as viewed from said sensor coil; and
a controller configured to specify first impedance coordinates of a resistance component and a reactance component of the impedance in rectangular coordinates and to perform phase rotation, parallel displacement, and expansion on the first impedance coordinates. - View Dependent Claims (11, 12, 14)
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13. An eddy current sensor comprising:
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a sensor coil disposed near a conductive film formed on a substrate;
a signal source configured to supply an AC signal to said sensor coil to produce an eddy current in the conductive film;
a detection circuit operable to detect the eddy current produced in the conductive film based on an impedance as viewed from said sensor coil;
a storage device operable to store a correction coefficient according to a deposition condition of the conductive film; and
a controller configured to specify a point including a resistance component and a reactance component of the impedance in rectangular coordinates and to correct the point by the correction coefficient stored in said storage device.
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15. An eddy current sensor comprising:
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a sensor coil disposed near a conductive film formed on a substrate;
a signal source configured to supply an AC signal to said sensor coil to produce an eddy current in the conductive film;
a detection circuit operable to detect the eddy current produced in the conductive film based on an impedance as viewed from said sensor coil; and
a controller configured to specify an impedance coordinates of a resistance component and a reactance component of the impedance in rectangular coordinates and to move the impedance coordinates on a semicircular locus in the rectangular coordinates according to progress of a process. - View Dependent Claims (16, 17, 18, 19, 20, 21, 22)
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23. An eddy current sensor comprising:
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a sensor coil disposed near a substrate having a plurality of zones;
a signal source configured to supply an AC signal to said sensor coil to produce an eddy current in the substrate;
a detection circuit operable to obtain signal data on the eddy current produced in the plurality of zones of the substrate; and
a controller configured to detect an endpoint of a process based on the signal data. - View Dependent Claims (24, 25, 26)
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Specification