Wafer measurement apparatus and operating method thereof
AssigneeSamsung Electronics Co., Ltd.
InventorsJaehyung Ahn, Inseok Park, Joonseo Song, Souk Kim, Younghoon Sohn
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Abstract
A wafer measurement apparatus includes an electronic-optical system configured to irradiate a wafer with an electron beam and acquire a raw signal by detecting electrons emitted by the wafer, and an image processing device configured to convert the raw signal acquired by the electronic-optical system into image data. The electronic-optical system includes a detector configured to acquire the raw signal. The detector calibrates a gain offset using a difference in electron emission yields of different materials.
Claims20
A wafer measurement apparatus, comprising:
- an electronic-optical system configured to irradiate a wafer with an electron beam and acquire a raw signal by detecting electrons emitted by the wafer;
- and
- an image processing device configured to convert the raw signal acquired by the electronic-optical system into image data,
- wherein the electronic-optical system comprises a detector configured to acquire the raw signal, and
- the detector calibrates a gain offset using a difference in electron emission yields of different materials.
An operating method of a wafer measurement apparatus, the method comprising:
- loading a wafer onto a stage;
- moving an electron beam to a test sample comprising a plurality of materials;
- controlling a gain offset of a detector using a gray level of a test detection signal emitted by the test sample;
- moving the electron beam to an image acquisition position after controlling the gain offset of the detector;
- and
- acquiring an image using a detection signal emitted at the image acquisition position, wherein the gain offset is controlled based on a difference in electron emission yields of the plurality of materials.
An operating method of a wafer measurement apparatus, the method comprising:
- acquiring a sample signal emitted by a test sample;
- determining whether detection calibration of a detector is to be performed using the sample signal;
- adjusting a gain offset of the detector when the detection calibration is to be performed;
- post-calibrating a gray level of a raw signal acquired at a predetermined position of a wafer when the detection calibration is not to be performed;
- and
- converting the raw signal into an 8-bit image using the calibrated gray level, wherein the gain offset is adjusted based on a difference in electron emission yields of different materials.
Dependencies are inferred from the claim text.