公开(公告)号：US20210199415A1

公开(公告)日：2021-07-01

申请号：US17122301

申请日：2020-12-15

Applicant: EBARA CORPORATION

Inventor： Hiroto YAMADA ,  Taro TAKAHASHI ,  Hiroaki SHIBUE ,  Atsushi ABE ,  Shinpei TOKUNAGA

IPC: G01B7/06 ,  H01L21/67

Abstract: 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.

公开(公告)号：US20240210353A1

公开(公告)日：2024-06-27

申请号：US18545448

申请日：2023-12-19

Applicant: EBARA CORPORATION

Inventor： Taro TAKAHASHI ,  Shinpei TOKUNAGA

IPC: G01N27/90 ,  G01N27/02 ,  H01L21/66

CPC classification number: G01N27/9006 ,  G01N27/023 ,  G01N27/9046 ,  H01L22/12

Abstract: The eddy current sensor includes a first detector that detects an eddy current generated in a semiconductor wafer WH and a second detector that detects the eddy current. The first detector includes a first exciting coil configured to generate the eddy current and a first detecting coil configured to detect the eddy current. The first exciting coil and the first detecting coil are air-core coils. The second detector includes second exciting coil configured to generate the eddy current and second detecting coil configured to detect the eddy current. The second exciting coil and the second detecting coil are coils with a magnetic core.

公开(公告)号：US20240077297A1

公开(公告)日：2024-03-07

申请号：US18504301

申请日：2023-11-08

Applicant: EBARA CORPORATION

Inventor： Hiroto YAMADA ,  Taro TAKAHASHI ,  Hiroaki SHIBUE ,  Atsushi ABE ,  Shinpei TOKUNAGA

IPC: G01B7/06 ,  H01L21/67

CPC classification number: G01B7/105 ,  H01L21/67253

Abstract: 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.

公开(公告)号：US20220063056A1

公开(公告)日：2022-03-03

申请号：US17410099

申请日：2021-08-24

Applicant: EBARA CORPORATION

Inventor： Atsushi ABE ,  Taro TAKAHASHI ,  Hiroaki SHIBUE ,  Shinpei TOKUNAGA ,  Katsuhide WATANABE

IPC: B24B49/10 ,  G01B7/06

Abstract: 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.