Spectroscopic Beam Profile Metrology
First Claim
1. A metrology system comprising:
- a multiple wavelength illumination source configured to provide a beam of illumination light having multiple wavelengths and a two-dimensional beam intensity cross-section;
a beam shaping element configured to reshape the beam of illumination light such that the reshaped beam of illumination light has a beam intensity cross-section that is approximately one dimensional;
a high numerical aperture (NA) objective configured to receive the reshaped beam of illumination light, illuminate a measurement site on a surface of a specimen with the reshaped beam of illumination light, and collect light from the measurement site in response to the illumination of the measurement site over a range of angles of incidence;
a first wavelength dispersive element configured to receive the collected light, transmit the collected light according to angle of incidence, and disperse the received collected light according to wavelength; and
a first two dimensional detector configured to detect the collected light transmitted by the first wavelength dispersive element according to angle of incidence along a first dimension of the first two dimensional detector and detect the collected light dispersed by the wavelength dispersive element according to wavelength along a second dimension of the first two dimensional detector.
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Accused Products
Abstract
A spectroscopic beam profile metrology system simultaneously detects measurement signals over a large wavelength range and a large range of angles of incidence (AOI). In one aspect, a multiple wavelength illumination beam is reshaped to a narrow line shaped beam of light before projection onto a specimen by a high numerical aperture objective. After interaction with the specimen, the collected light is passes through a wavelength dispersive element that projects the range of AOIs along one direction and wavelength components along another direction of a two-dimensional detector. Thus, the measurement signals detected at each pixel of the detector each represent a scatterometry signal for a particular AOI and a particular wavelength. In another aspect, a hyperspectral detector is employed to simultaneously detect measurement signals over a large wavelength range, range of AOIs, and range of azimuth angles.
40 Citations
20 Claims
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1. A metrology system comprising:
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a multiple wavelength illumination source configured to provide a beam of illumination light having multiple wavelengths and a two-dimensional beam intensity cross-section; a beam shaping element configured to reshape the beam of illumination light such that the reshaped beam of illumination light has a beam intensity cross-section that is approximately one dimensional; a high numerical aperture (NA) objective configured to receive the reshaped beam of illumination light, illuminate a measurement site on a surface of a specimen with the reshaped beam of illumination light, and collect light from the measurement site in response to the illumination of the measurement site over a range of angles of incidence; a first wavelength dispersive element configured to receive the collected light, transmit the collected light according to angle of incidence, and disperse the received collected light according to wavelength; and a first two dimensional detector configured to detect the collected light transmitted by the first wavelength dispersive element according to angle of incidence along a first dimension of the first two dimensional detector and detect the collected light dispersed by the wavelength dispersive element according to wavelength along a second dimension of the first two dimensional detector. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. A metrology system comprising:
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a multiple wavelength illumination source configured to provide a beam of illumination light having multiple wavelengths and a beam intensity cross-section that is two dimensional; a high numerical aperture (NA) objective configured to receive the beam of illumination light, illuminate a measurement site on a surface of a specimen with the beam of illumination light, and collect light from the measurement site in response to the illumination of the measurement site over a range of angles of incidence; and a hyperspectral detector configured to detect the collected light according to angle of incidence along a first dimension of the hyperspectral detector, detect the collected light according to azimuth angle along a second dimension of the hyperspectral detector, and detect the collected light according to wavelength along a third dimension of the hyperspectral detector.
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17. A method comprising:
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providing a beam of illumination light having multiple wavelengths and a beam intensity cross-section that is two dimensional; reshaping the beam of illumination light such that the reshaped beam of illumination light has a beam intensity cross-section that is approximately one dimensional; illuminating a measurement site on a surface of a specimen with the reshaped beam of illumination light; collecting light from the measurement site in response to the illumination of the measurement site over a range of angles of incidence; transmitting the collected light according to angle of incidence; dispersing the received collected light according to wavelength; detecting the transmitted collected light along a first dimension of a first two dimensional detector; and detecting the dispersed collected light along a second dimension of the first two dimensional detector. - View Dependent Claims (18, 19, 20)
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Specification