Ebara Corporation

Shinpei Tokunaga

Taro Takahashi

Hiroaki Shibue

Atsushi Abe

Hiroto Yamada

Yuta Suzuki

Katsuhide Watanabe

Nobuyuki Takada

Akihiko Ogawa

Yuji Yagi

Shigeyuki Furuya

An eddy current sensor has an exciting coil and a detection coil. A holding circuit holds reference data indicating a characteristic of an output signal output from the detection coil at a reference state and outputs the reference data at a state other than the reference state. A pseudo signal generating circuit generates and outputs a balance coil pseudo signal corresponding to the output signal output from the detection coil at the reference state from the reference data output from the holding circuit. A bridge circuit, at the state other than the reference state, receives the output signal output from the detection coil and the balance coil pseudo signal and outputs a bridge output signal corresponding to a difference between the output signal and the balance coil pseudo signal as a bridge output signal.

Output signal processing apparatus for eddy current sensor

An eddy current sensor assembly includes an eddy current sensor and an output signal processing circuit that processes an output signal from the eddy current sensor. The output signal processing circuit includes a mixer circuit that accepts the output signal and a signal of the predetermined frequency as input, multiplies the two signals received as input, and outputs an output signal obtained by the multiplication, and a low-pass filter that accepts the output signal output by the mixer circuit as input, cuts a high-frequency signal included in the output signal received as input, and outputs at least a direct-current (DC) signal.

Output signal processing circuit for eddy current sensor and output signal processing method for eddy current sensor

An eddy current detection device configured to form a stronger magnetic field in a polishing target and a polishing apparatus employing the same eddy current detection device are provided. An eddy current detection device that can be disposed near a semiconductor wafer on which a conductive film is formed includes a plurality of eddy current sensors. The plurality of eddy current sensors are disposed near to one another. Each of the plurality of eddy current sensors includes a pot core, an exciting coil disposed in the pot core and configured to form an eddy current in the conductive film, and a detection coil disposed in the pot core and configured to detect the eddy current formed in the conductive film.

Eddy current detection device and polishing apparatus

A first and a second substrate polishing apparatus and are provided with a film thickness sensor for measuring a film thickness of layer to be polished and polish the layer by pressing the substrate against a polishing pad. The first substrate polishing apparatus outputs difference between output value of the film thickness sensor when an underlayer is exposed and output value of the film thickness sensor when the substrate is not present, as a first offset value. The second substrate polishing apparatus has a storage unit that stores information of the first offset value, an output correction unit that corrects the output value from the film thickness sensor based on the first offset value, and an end point detection unit that outputs control signal indicating end point of substrate polishing when measured value of the film thickness of the layer calculated based on the corrected output value reaches target value.

Substrate polishing system, substrate polishing method and substrate polishing apparatus

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Tokyo, Japan

Shinpei Tokunaga