Semiconductor measurement apparatus
A semiconductor measurement apparatus includes an illuminator configured to output light having a first wavelength band and light having a second wavelength band, different from the first wavelength band, a stage on which a test object is positioned, a camera configured to receive light reflected or scattered from the test object or transmitted through the test object, and a controller configured to control the illuminator and the camera, and to measure, based on information indicated by the light received by the camera, a plurality of structures included in the test object. The controller is configured to set an exposure time of the camera to a first exposure time while the illuminator outputs the light having the first wavelength band, and to set the exposure time of the camera to a second exposure time, different from the first exposure time, while the illuminator outputs the light having the second wavelength band.
1 . A semiconductor measurement apparatus comprising:
an illuminator configured to emit output light;
a stage configured to position a semiconductor test object such that the output light from the illuminator is incident thereon;
a camera configured to receive light that is reflected or scattered from the semiconductor test object or is transmitted through the semiconductor test object; and
a controller configured to measure an intensity of a signal output by the camera, in response to setting an exposure time of the camera to a reference exposure time and setting a wavelength band of the output light from the illuminator to each of a plurality of wavelength bands,
wherein the controller is configured to compare intensity of respective signals output by the camera in each of the plurality of wavelength bands with a predetermined target intensity and determine respective exposure times of the camera responsive thereto, wherein the respective exposure times for at least some of the plurality of wavelength bands are different from each other such that the plurality of wavelength bands produced by the illuminator each have substantially a same intensity to the camera.
2 . The semiconductor measurement apparatus of claim 1 , wherein the semiconductor test object is a bare wafer.
3 . The semiconductor measurement apparatus of claim 2 , wherein the controller is configured to measure a critical dimension of a structure included in a semiconductor object different from the bare wafer, and formed by a semiconductor process.
4 . The semiconductor measurement apparatus of claim 2 , wherein the controller is configured to measure overlays of a plurality of structures included in a semiconductor object different from the bare wafer, and
wherein the overlays correspond to an alignment state of the plurality of structures formed on each of layers included in the semiconductor object and stacked on each other.
5 . The semiconductor measurement apparatus of claim 1 , wherein the plurality of wavelength bands include a first wavelength band and a second wavelength band different from the first wavelength band, and
wherein the controller is configured to set the exposure time of the camera for the first wavelength band to a first exposure time among the respective exposure times, and to set the exposure time of the camera for the second wavelength band to a second exposure time among the respective exposure times, wherein the second exposure time is different from the first exposure time.
6 . The semiconductor measurement apparatus of claim 1 , wherein the plurality of wavelength bands include two or more first wavelength bands grouped into a first group and two or more second wavelength bands grouped into a second group, and
wherein the controller is configured to determine the respective exposure times of the camera as including a first exposure time for the two or more first wavelength bands, and a second exposure time for the two or more second wavelength bands.
7 . The semiconductor measurement apparatus of claim 6 , wherein the first exposure time is determined based on a first intensity of a first signal output from the camera in response to receiving the output light comprising one of the two or more first wavelength bands and the predetermined target intensity, and
wherein the second exposure time is determined based on a second intensity of a second signal output from the camera in response to receiving the output light comprising one of the two or more second wavelength bands and the predetermined target intensity.
8 . The semiconductor measurement apparatus of claim 6 , wherein the first exposure time is an average of exposure times determined based on the intensity of the respective signals output from the camera in response to receiving the output light comprising each of the two or more first wavelength bands and the predetermined target intensity.
9 . The semiconductor measurement apparatus of claim 1 , wherein the illuminator includes a light source and a monochromator configured to adjust a wavelength band of primary light output by the light source to one of the plurality of wavelength bands, and to emit the output light comprising the one of the plurality of wavelength bands.
10 . The semiconductor measurement apparatus of claim 9 , wherein the monochromator includes a grating structure configured to reflect the primary light output by the light source, and a slit structure configured to allow the light reflected from the grating structure to pass through, and
wherein the controller is configured to adjust the wavelength band of the primary light by changing a posture of the grating structure.
11 . The semiconductor measurement apparatus of claim 1 ,
wherein, when the camera receives the output light that is emitted from the illuminator and is reflected or scattered from the semiconductor test object or is transmitted through the the semiconductor test object, the controller is configured to determine, based on an intensity of a first signal generated by the camera in response to the output light, a plurality of individual exposure times respectively matched to the plurality of wavelength bands,
wherein the controller is configured to acquire a second signal from the camera while setting an exposure time of the camera to a respective one of the plurality of individual exposure times and controlling the illuminator to emit the output light having a wavelength band among the plurality of wavelength bands, which is matched to the respective one of the plurality of individual exposure times that is set in the camera, and
wherein the controller is configured to measure, based on the second signal that was acquired from the camera, a plurality of structures that reflect, scatter or transmit the output light.
12 . The semiconductor measurement apparatus of claim 11 , wherein the controller is configured to generate, using the second signal, at least one of an intensity difference or a phase difference between polarization components included in light incident on the camera, a reflectance based on the light incident on the camera, an intensity of the light incident on the camera, or elements of a Mueller matrix corresponding to the light incident on the camera.
13 . The semiconductor measurement apparatus of claim 9 , wherein
the illuminator is configured to provide the output light comprising first light having a first wavelength band and second light having a second wavelength band that is different from the first wavelength band;
wherein the controller is configured to control the illuminator and the camera, and
wherein the controller is configured to set an exposure time of the camera to a first exposure time while the illuminator outputs the first light having the first wavelength band, and to set the exposure time of the camera to a second exposure time, different from the first exposure time, while the illuminator outputs the second light having the second wavelength band.
14 . The semiconductor measurement apparatus of claim 13 , wherein the controller is configured to measure the intensity of the signal output by the camera, while the illuminator is configured to emit the output light to a first area of the semiconductor test object, and
wherein the controller is configured to measure a critical dimension of a structure included in a second area of the semiconductor test object, and formed by a semiconductor process, and wherein the second area is different from the first area.
15 . The semiconductor measurement apparatus of claim 13 , wherein the illuminator further includes:
at least one light source configured to output primary light having a plurality of wavelength bands including the first wavelength band and the second wavelength band; and
a monochromator configured to decompose primary light output from the at least one light source into the plurality of wavelength bands, and to select and output light having one wavelength band among the plurality of wavelength bands as the output light.
16 . The semiconductor measurement apparatus of claim 15 , wherein
the monochromator includes a grating structure configured to decompose the primary light output from the at least one light source into the plurality of wavelength bands,
wherein the controller is configured to select a wavelength band among the plurality of wavelength bands by adjusting at least one of a posture of the grating structure or an angle at which the at least one light source outputs the primary light, and
wherein the controller is configured to change the exposure time of the camera depending on at least one of the posture of the grating structure or the angle at which the at least one light source outputs the primary light.
17 . The semiconductor measurement apparatus of claim 15 , wherein the monochromator includes at least one of a prism configured to decompose the primary light output by the at least one light source into the plurality of wavelength bands, or an optical filter.
18 . The semiconductor measurement apparatus of claim 1 , wherein the semiconductor test object includes a plurality of first structures, and
wherein the controller is configured to measure a critical dimension of a second structure included in a semiconductor object different from the semiconductor test object, and formed by a semiconductor process.
19 . The semiconductor measurement apparatus of claim 1 , wherein the semiconductor test object includes a plurality of first structures,
wherein the controller is configured to measure overlays of a plurality of second structures included in a semiconductor object different from the semiconductor test object, and
wherein the overlays correspond to an alignment state of the plurality of second structures formed on each of layers included in the semiconductor object and stacked on each other.
20 . The semiconductor measurement apparatus of claim 1 , wherein the controller is configured to measure the intensity of the signal output by the camera, while the illuminator is configured to emit the output light to a first area of the semiconductor test object,
wherein the controller is configured to measure overlays of a plurality of structures included in a second area of the semiconductor test object, and the second area is different from the first area, and wherein the overlays correspond to an alignment state of the plurality of structures formed on each of layers included in the semiconductor test object and stacked on each other.