CN-119438221-B - Semiconductor detection equipment

CN119438221BCN 119438221 BCN119438221 BCN 119438221BCN-119438221-B

Abstract

The invention relates to the technical field of optical detection, in particular to semiconductor detection equipment, which comprises a re-detection light source for emitting re-detection light, a bright field light source for emitting bright field light and a dark field light source for emitting dark field light, wherein the re-detection light, the bright field light and the dark field light are respectively guided to irradiate the surface of a wafer, the re-detection light is reflected by the wafer to form re-detection signal light, the bright field light is reflected by the wafer to form bright field signal light, the dark field light is scattered by the wafer to form dark field signal light, and an optical separation element is used for collecting the bright field signal light, the dark field signal light and the re-detection signal light and carrying out spatial separation so that the dark field signal light, the bright field signal light and the re-detection signal light are emitted to different transmission paths to be imaged respectively, wherein dark field illumination spots formed on the surface of the wafer by the dark field light, bright field illumination spots formed on the surface of the wafer by the bright field light and the re-detection illumination spots formed on the surface of the wafer are not overlapped with each other. The invention is at least beneficial to improving the detection speed and the detection precision of wafer defect detection.

Inventors

CHEN LU
LIU JIANPENG
LIANG WENJUN
WANG FUWANG
QIU ZHIYUAN

Assignees

上海中科飞测半导体科技有限公司

Dates

Publication Date: 20260508
Application Date: 20241212

Claims (17)

1. A semiconductor inspection apparatus, comprising: A re-inspection light source for emitting re-inspection light, a bright field light source for emitting bright field light, and a dark field light source for emitting dark field light, wherein the re-inspection light, the bright field light, and the dark field light are respectively guided to irradiate the surface of the wafer, the re-inspection light is reflected by the wafer to form re-inspection signal light, the bright field light is reflected by the wafer to form bright field signal light, and the dark field light is scattered by the wafer to form dark field signal light; An optical separation element for collecting the bright field signal light, the dark field signal light and the retest signal light and spatially separating the same, so that the dark field signal light, the bright field signal light and the retest signal light are emitted to different transmission paths to be imaged respectively; The bright field signal light, the dark field signal light and the retest signal light reach the optical separation element along a common light path, the optical separation element is provided with a through hole, a first reflecting surface and a second reflecting surface, the bright field signal light incident on the optical separation element is reflected by the first reflecting surface and then emitted to a first transmission path, the dark field signal light incident on the optical separation element is reflected by the second reflecting surface and then emitted to a second transmission path, and the retest signal light incident on the optical separation element is emitted to a third transmission path through the through hole; Wherein, the dark field illumination light spot formed by the dark field light on the surface of the wafer, the bright field illumination light spot formed by the bright field light on the surface of the wafer and the recheck illumination light spot formed by the recheck light on the surface of the wafer are not overlapped.
2. The semiconductor inspection apparatus according to claim 1, wherein a distance between two of the dark field illumination spot, the bright field illumination spot, and the review illumination spot having a largest pitch is greater than a first preset value in a range of 0.1mm to 0.5mm and less than a second preset value in a range of 1mm to 3 mm.
3. The semiconductor inspection apparatus according to claim 1 or 2, wherein the review illumination spot is located between the dark field illumination spot and the bright field illumination spot, and a distance from the dark field illumination spot to the review illumination spot is the same as or different from a distance from the bright field illumination spot to the review illumination spot.
4. The semiconductor inspection apparatus according to claim 1, characterized in that the semiconductor inspection apparatus further comprises: The bright field detector is arranged on the first transmission path and is used for imaging bright field signal light emitted by the optical separation element; The dark field detector is arranged on the second transmission path and is used for imaging dark field signal light emitted by the optical separation element; and the re-detection detector is arranged on the third transmission path and is used for imaging the re-detection signal light emitted by the optical separation element.
5. The semiconductor inspection apparatus according to claim 4, wherein the optical separation element is a trapezoid prism, the through hole penetrates through a top surface and a bottom surface of the trapezoid prism, the first reflection surface and the second reflection surface are respectively provided on two oblique side surfaces of the trapezoid prism, a transmission direction of the dark field signal light, a transmission direction of the bright field signal light and a transmission direction of the review signal light emitted by the trapezoid prism are all distributed in the same horizontal plane, and the bright field detector, the dark field detector and the review detector are provided on the same horizontal mesa to reduce an influence of horizontal mesa vibration on imaging.
6. The semiconductor inspection apparatus of claim 4, wherein the bright field light source and the dark field light source comprise continuous light sources, the review light source comprises a strobe light source, the bright field detector and the dark field detector comprise line scan cameras, and the review detector comprises a color area array camera.
7. The semiconductor inspection apparatus according to claim 4, further comprising an objective lens and a spectroscopic element disposed in order in a direction away from the wafer, the light-re-inspection light and the light-bright-field light each being incident on the wafer surface through the spectroscopic element and the objective lens in order, the light-bright-field signal light, the dark-field signal light and the light-re-inspection signal light each being incident on the optical separation element through the objective lens and the spectroscopic element in order, the light-bright-field signal light, the dark-field signal light and the light-re-inspection signal light being transmitted in a common optical path between the objective lens and the optical separation element and kept spatially separated from each other.
8. The semiconductor inspection apparatus according to claim 7, further comprising an imaging lens group disposed between the spectroscopic element and the optical separation element, wherein the bright field signal light, the dark field signal light, and the review signal light emitted from the spectroscopic element are incident to the optical separation element through the imaging lens group.
9. The semiconductor inspection apparatus according to claim 8, wherein the spectroscopic element includes a spectroscope, an angle between a spectroscopic surface of the spectroscope facing the objective lens and a horizontal direction is 45 °, and the imaging lens group, the bright field detector, the dark field detector, and the review detector are disposed on the same horizontal mesa.
10. The semiconductor inspection apparatus of claim 8, wherein the bright field detector has a target surface size that is the same as a target surface size of the dark field detector, and the imaging field of view of the imaging lens group satisfies the following equation: ; Wherein D is the diameter of the imaging view field, l is the target surface length, w is the target surface width, and D is the interval distance between the bright field illumination light spot and the dark field illumination light spot.
11. The semiconductor inspection apparatus according to claim 7, wherein the transmittance of the spectroscopic element is in a range of 0 to 50%, and the reflectance of the spectroscopic element is in a range of 50 to 100%.
12. The semiconductor inspection apparatus according to claim 7, further comprising a review illumination modulation lens group and an illumination lens group provided between the review light source and the light splitting element, wherein review light emitted from the review light source is incident to the light splitting element through the review illumination modulation lens group and the illumination lens group in order.
13. The semiconductor inspection apparatus according to claim 12, wherein the illumination lens group is further disposed between the bright field light source and the light splitting element, the semiconductor inspection apparatus further comprising a bright field illumination modulation lens group, and bright field light emitted from the bright field light source is incident to the light splitting element through the bright field illumination modulation lens group and the illumination lens group in order.
14. The semiconductor inspection apparatus according to claim 7, wherein the objective lens includes a plurality of sub objective lenses each having a different magnification, one of the plurality of sub objective lenses being located in a beam transmission optical path between the spectroscopic element and the wafer, the sub objective lens located in the beam transmission optical path being switchable.
15. The apparatus according to claim 7, further comprising an autofocus module including an autofocus light source and a dichroic mirror disposed between the spectroscopic element and the objective lens, the autofocus light source for emitting focused light directed through the dichroic mirror to irradiate the wafer surface, the focused light having a wavelength different from the wavelength of the re-inspection light, the wavelength of the bright field light, the wavelength of the dark field signal light, the wavelength of the bright field signal light, and the wavelength of the re-inspection signal light.
16. The semiconductor inspection apparatus of claim 1 further comprising a dark field illumination modulation lens set mated with the dark field light source, wherein dark field light from the dark field light source is incident on the wafer surface through the dark field illumination modulation lens set.
17. The semiconductor inspection apparatus of claim 1 further comprising a carrier having a carrier surface for carrying the wafer.

Description

Semiconductor detection equipment Technical Field The invention belongs to the technical field of optical detection, and particularly relates to semiconductor detection equipment. Background In the process of manufacturing semiconductor chips, unavoidable contamination and defects caused by manufacturing errors are important causes of failure of semiconductor chips, and therefore, wafer defect inspection of wafers used for manufacturing semiconductor chips during the manufacture of semiconductor chips can improve yield and thus obtain higher profits. Among the existing wafer defect detection devices, the defect detection method based on optical imaging has the advantages of rapid detection and no contact, and is the most commonly used means for detecting wafer defects. For wafer defect detection based on optical imaging, the detection speed and the detection precision are important indexes related to detection, wherein the detection precision refers to the minimum size of the detected defects, and it is understood that increasing the magnification can obtain smaller optical resolution, improve the detection precision, and simultaneously reduce the detection speed. In order to realize rapid and high-precision defect detection, wafer defect detection generally comprises two steps of primary detection and secondary detection, wherein the primary detection is used for scanning and detecting a designated area by adopting low magnification so as to preliminarily obtain the defect position in the area and the preliminary form information of the defect, in the secondary detection, the defect position is moved to a secondary detection probe, and the secondary detection imaging is carried out by adopting high magnification so as to obtain a defect image with higher precision, so that more detailed information of the defect is analyzed. But currently, the detection accuracy and the detection speed of wafer defect detection based on optical imaging are required to be improved. Disclosure of Invention In view of the above, the present invention is directed to a semiconductor inspection apparatus, which is at least beneficial to improving the inspection speed and the inspection accuracy of wafer defect inspection. In order to achieve the above purpose, the technical scheme of the invention is realized as follows: the invention provides a semiconductor detection device which comprises a re-detection light source for emitting re-detection light, a bright field light source for emitting bright field light and a dark field light source for emitting dark field light, wherein the re-detection light, the bright field light and the dark field light are respectively guided and irradiated on the surface of a wafer, the re-detection light is reflected by the wafer to form re-detection signal light, the bright field light is reflected by the wafer to form bright field signal light, the dark field light is scattered by the wafer to form dark field signal light, an optical separation element is used for collecting the bright field signal light, the dark field signal light and the re-detection signal light and performing spatial separation so that the dark field signal light, the bright field signal light and the re-detection signal light are emitted to different transmission paths to respectively image, and dark field illumination spots formed on the surface of the wafer by the dark field light, bright field illumination spots formed on the surface of the wafer by the re-detection light are not overlapped with each other. Further, the distance between the dark field illumination light spot, the bright field illumination light spot and the recheck illumination light spot with the largest distance is larger than a first preset value and smaller than a second preset value, the first preset value is in the range of 0.1mm to 0.5mm, and the second preset value is in the range of 1mm to 3 mm. Further, the recheck lighting spot is located between the dark field lighting spot and the bright field lighting spot, and the distance from the dark field lighting spot to the recheck lighting spot is the same as or different from the distance from the bright field lighting spot to the recheck lighting spot. Further, the bright field signal light, the dark field signal light and the retest signal light reach the optical separation element along the common light path, the optical separation element is provided with a through hole, a first reflecting surface and a second reflecting surface, the bright field signal light incident on the optical separation element is reflected by the first reflecting surface and then emitted to the first transmission path, the dark field signal light incident on the optical separation element is reflected by the second reflecting surface and then emitted to the second transmission path, and the retest signal light incident on the optical separation element is emitted to the third transmission path through the through hole.