Semiconductor detection equipment

Abstract

The invention relates to the technical field of optical detection, in particular to semiconductor detection equipment, which comprises a reinspection light source for emitting reinspection light, a bright field light source for emitting bright field light and a dark field light source for emitting dark field light, the reinspection light, the bright field light and the dark field light are respectively guided to irradiate the surface of a wafer, the reinspection light is reflected by the wafer to form reinspection signal light, and the reinspection signal light is transmitted to the light source. The bright-field light is reflected by the wafer to form bright-field signal light, and the dark-field light source is scattered by the wafer to form dark-field signal light; the optical separation element is used for collecting the bright-field signal light, the dark-field signal light and the reinspection signal light and performing spatial separation, so that the dark-field signal light, the bright-field signal light and the reinspection signal light are emitted to different transmission paths for respective imaging; wherein a dark field illumination light spot formed by the dark field light on the surface of the wafer, a bright field illumination light spot formed by the bright field light on the surface of the wafer and a reinspection illumination light spot formed by the reinspection light on the surface of the wafer do not coincide with one another. The wafer defect detection device is at least beneficial to improving the detection speed and the detection precision of wafer defect detection.

Description

Technical Field

[0001] The invention belongs to the technical field of optical detection, and in particular relates to a semiconductor detection device. Background Art

[0002] In the process of semiconductor chip processing, the inevitable contamination and defects caused by manufacturing errors are the main reasons for the failure of semiconductor chips. Therefore, during the manufacturing of semiconductor chips, wafer defect detection on the wafers used to prepare semiconductor chips can improve the yield rate and thus obtain higher profits. Among the existing wafer defect detection equipment, the defect detection method based on optical imaging has the advantages of fast detection and non-contact, and is the most commonly used means of wafer defect detection.

[0003] For wafer defect detection based on optical imaging, detection speed and detection accuracy are important indicators involved in the detection. Among them, detection accuracy refers to the minimum size of defects that can be detected. It is understandable that increasing the magnification can obtain a smaller optical resolution and improve detection accuracy, but it also reduces the detection speed. In order to achieve fast and high-precision defect detection, wafer defect detection usually includes two steps: initial inspection and re-inspection. Among them, the initial inspection is used to scan and detect the specified area with a low magnification to preliminarily obtain the defect location and preliminary morphological information of the defect in the area. During the re-inspection, the defect location is moved to the re-inspection probe, and re-inspection imaging is performed with a high magnification to obtain a higher-precision defect image and analyze more detailed information about the defect.

[0004] However, the detection accuracy and detection speed of wafer defect detection based on optical imaging need to be improved. Summary of the invention

[0005] In view of this, the present invention aims to provide a semiconductor inspection device, which is at least beneficial to improving the inspection speed and inspection accuracy of wafer defect inspection.

[0006] To achieve the above object, the technical solution created by the present invention is implemented as follows:

[0007] The invention provides a semiconductor detection device, comprising: a re-test light source for emitting re-test 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-test light, the bright field light, and the dark field light are respectively guided to irradiate the surface of a chip, the re-test light is reflected by the chip to form a re-test signal light, the bright field light is reflected by the chip to form a bright field signal light, and the dark field light source is scattered by the chip to form a dark field signal light; an optical separation element is used to collect the bright field signal light, the dark field signal light, and the re-test signal light and perform spatial separation, so that the dark field signal light, the bright field signal light, and the re-test signal light are emitted to different transmission paths to form images respectively; wherein the dark field illumination spot formed by the dark field light on the chip surface, the bright field illumination spot formed by the bright field light on the chip surface, and the re-test illumination spot formed by the re-test light on the chip surface do not overlap with each other.

[0008] Furthermore, the distance between the dark field illumination spot, the bright field illumination spot and the re-inspection illumination spot with the largest spacing is greater than a first preset value and less than a second preset value, the first preset value is in the range of 0.1 mm to 0.5 mm, and the second preset value is in the range of 1 mm to 3 mm.

[0009] Furthermore, the re-inspection illumination spot is located between the dark field illumination spot and the bright field illumination spot, and the distance from the dark field illumination spot to the re-inspection illumination spot is the same as or different from the distance from the bright field illumination spot to the re-inspection illumination spot.

[0010] Furthermore, the bright field signal light, the dark field signal light and the re-check signal light reach the optical separation element along a common optical path, and the optical separation element has a through hole, a first reflection surface and a second reflection surface; the bright field signal light incident to the optical separation element is reflected by the first reflection surface and then emitted to the first transmission path, the dark field signal light incident to the optical separation element is reflected by the second reflection surface and then emitted to the second transmission path, and the re-check signal light incident to the optical separation element passes through the through hole and is emitted to the third transmission path.

[0011] Furthermore, the semiconductor detection equipment also includes: a bright field detector, which is arranged on the first transmission path and is used to image the bright field signal light emitted by the optical separation element; a dark field detector, which is arranged on the second transmission path and is used to image the dark field signal light emitted by the optical separation element; and a re-inspection detector, which is arranged on the third transmission path and is used to image the re-inspection signal light emitted by the optical separation element.

[0012] Furthermore, the optical separation element is a trapezoidal prism, and the through hole passes through the top and bottom surfaces of the trapezoidal prism. The first reflection surface and the second reflection surface are respectively arranged on the two inclined side surfaces of the trapezoidal prism. The transmission direction of the dark field signal light, the transmission direction of the bright field signal light and the transmission direction of the re-inspection signal light emitted by the trapezoidal prism are all distributed in the same horizontal plane. The bright field detector, the dark field detector and the re-inspection detector are arranged on the same horizontal platform surface to reduce the influence of the vibration of the horizontal platform surface on the imaging.

[0013] Further, the bright field light source and the dark field light source include continuous light sources; the re-inspection light source includes a stroboscopic light source; the bright field detector and the dark field detector include line scan cameras; and the re-inspection detector includes a color array camera.

[0014] Furthermore, the semiconductor detection equipment also includes: an objective lens and a spectroscopic element arranged in sequence along a direction away from the chip, the re-inspection light and the bright field light are incident on the chip surface through the spectroscopic element and the objective lens in sequence, the bright field signal light, the dark field signal light and the re-inspection signal light are incident on the optical separation element through the objective lens and the spectroscopic element in sequence, the bright field signal light, the dark field signal light and the re-inspection signal light are transmitted in a common optical path between the objective lens and the optical separation element and maintain spatial isolation from each other.

[0015] Furthermore, the semiconductor detection equipment also includes an imaging mirror group, which is arranged between the spectroscopic element and the optical separation element. The bright field signal light, dark field signal light and re-inspection signal light emitted from the spectroscopic element all pass through the imaging mirror group and are incident on the optical separation element.

[0016] Furthermore, the spectroscopic element includes a spectroscope, the angle between the spectroscopic surface of the spectroscope facing the objective lens and the horizontal direction is 45°, and the imaging lens group, the bright field detector, the dark field detector and the re-inspection detector are arranged on the same horizontal platform.

[0017] Furthermore, the target size of the bright field detector is the same as that of the dark field detector, and the imaging field of the imaging lens group satisfies the following formula:

[0018]

[0019] Wherein, D is the diameter of the imaging field of view, l is the length of the target surface, w is the width of the target surface, and d is the distance between the bright field illumination spot and the dark field illumination spot.

[0020] Furthermore, the transmittance of the light-splitting element is in the range of 0 to 50%, and the reflectance of the light-splitting element is in the range of 50 to 100%.

[0021] Furthermore, the semiconductor inspection device also includes a re-inspection illumination modulation mirror group and an illumination mirror group arranged between the re-inspection light source and the spectroscopic element, and the re-inspection light emitted by the re-inspection light source passes through the re-inspection illumination modulation mirror group and the illumination mirror group in sequence and is incident on the spectroscopic element.

[0022] Furthermore, the illumination mirror group is also arranged between the bright field light source and the spectroscopic element, and the semiconductor detection equipment also includes a bright field illumination modulation mirror group, and the bright field light emitted by the bright field light source passes through the bright field illumination modulation mirror group and the illumination mirror group in sequence and is incident on the spectroscopic element.

[0023] Furthermore, the objective lens includes a plurality of sub-objective lenses, each of which has a different magnification, and one of the plurality of sub-objective lenses is located in the light beam transmission path between the beam splitting element and the chip, and the sub-objective lens located in the light beam transmission path is switchable.

[0024] Furthermore, the semiconductor detection equipment also includes an automatic focusing module, which includes: an automatic focusing light source and a dichroic mirror, the dichroic mirror is arranged between the spectroscopic element and the objective lens, the automatic focusing light source is used to emit focused light, the focused light is guided by the dichroic mirror to irradiate the chip surface, and the wavelength of the focused light is 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.

[0025] Furthermore, the semiconductor detection equipment also includes a dark field illumination modulation mirror group cooperating with the dark field light source, and the dark field light emitted by the dark field light source is incident on the wafer surface through the dark field illumination modulation mirror group.

[0026] Furthermore, the semiconductor testing equipment also includes a carrier platform having a carrier surface for carrying a wafer.

[0027] Compared with the prior art, the invention can achieve the following beneficial effects:

[0028] In the embodiment of the present invention, the bright field light source, the dark field light source and the re-inspection light source are independent of each other, thus avoiding the problem of limited wavelength selection during the detection process; the bright field signal light, the re-inspection signal light and the dark field signal light are independent of each other and do not overlap with each other, thus avoiding splitting the signal light to obtain the bright field signal light and the re-inspection signal light, which is beneficial to ensuring that the bright field signal light and the re-inspection signal light with higher intensity are obtained, thereby facilitating improving the detection accuracy; and the distance between the two of the dark field illumination spot, the bright field illumination spot and the re-inspection illumination spot with the largest distance between them will not be too far, thus, in the process of switching between bright field detection, dark field detection and re-inspection, the difficulty of locating the same detection position is avoided, thereby facilitating rapid switching between different detection methods and improving the detection speed. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The drawings constituting part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments and descriptions of the present invention are used to explain the present invention and do not constitute an improper limitation on the present invention. In the drawings:

[0030] Figure 1A schematic diagram of the structure of a semiconductor testing device according to an embodiment of the present invention;

[0031] Figure 2 A schematic diagram of the structure of the optical separation element according to an embodiment of the present invention;

[0032] Figure 3 Another structural schematic diagram of the semiconductor detection device according to the embodiment of the present invention;

[0033] Figure 4 A schematic diagram of the imaging field layout of an imaging lens assembly of a semiconductor inspection device according to an embodiment of the present invention;

[0034] Figure 5 It is a schematic diagram of a single-frame image corresponding to a stroboscopic light source and a single-frame image corresponding to a constant light source.

[0035] Explanation of the reference numerals: 120, re-inspection light source; 100, bright field light source; 110, dark field light source; 191, chip; 180, optical separation element; 183, through hole; 181, first reflection surface; 182, second reflection surface; 200, bright field detector; 210, dark field detector; 220, re-inspection detector; 160, objective lens; 150, spectrometer; 170, imaging lens group; 121, re-inspection illumination modulator lens group; 130, illumination lens group; 101, bright field illumination modulator lens group; 122, first reflection mirror group; 140, second reflection mirror group; 161, sub-objective lens; 230, autofocus light source; 231, dichroic mirror; 111, dark field illumination modulator lens group; 190, carrier platform. DETAILED DESCRIPTION

[0036] After analysis, it was found that for chip defect detection, the detection time mainly depends on the initial inspection scanning detection time, the number of defects in the re-inspection, and the positioning speed of the defect position. Within a fixed detection time, how to improve the initial inspection defect identification ability has become the key to improving the accuracy of chip defect detection. Considering that there are many types of defects that may exist on the chip, bright field imaging and dark field imaging have different resolution capabilities for different types of defects. It is proposed to use bright field imaging and dark field imaging detection methods in the initial inspection. In this way, how to reasonably set the optical path of bright field imaging, dark field imaging, and re-inspection imaging has become the key to chip defect detection technology based on optical imaging.

[0037] Existing implementation schemes can be divided into three categories: the first scheme sets up two or three completely independent optical systems to perform bright field imaging, dark field imaging and re-inspection imaging respectively. In this way, different optical systems need to be switched to switch between bright field detection, dark field detection and re-inspection, which increases the difficulty of locating the defect position, and thus greatly increases the detection time; the second scheme adopts a common optical path design. The field of view corresponding to the bright field and the dark field is the same. Bright field imaging and dark field imaging use light sources of different wavelengths for illumination. Different wavelengths of light are separated at the signal collection end to achieve simultaneous imaging of bright field and dark field, and then re-inspection is achieved by splitting the signal light. Considering the sensitivity of different defect materials to the wavelength of detection light, The degree of detection is different, and the detection wavelength selection of bright field and dark field in this scheme is limited; the third type of scheme also adopts a common optical path design, and the bright field and dark field correspond to different areas of the field of view respectively, to achieve regional detection of bright field and dark field, the re-inspection and the bright field share the same light source, and the bright field collected signal light is split to achieve re-inspection imaging (such as the optical scheme disclosed in patent US20090059215A1). This scheme realizes simultaneous detection of bright field and dark field under the same optical path system, and can well realize fast and high-precision judgment of defect positions, but the re-inspection splitting reduces the intensity of the bright field signal and the re-inspection signal. At the same time, the rapid movement of the chip during the re-inspection is likely to cause the re-inspection imaging to produce a smear phenomenon, which in turn affects the detection accuracy.

[0038] In order to make the purpose, technical solution and advantages of the invention more clear, the invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described here are only used to explain the invention and do not constitute a limitation of the invention.

[0039] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0040] In the description of the invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the invention, unless otherwise specified, the meaning of "multiple" is two or more.

[0041] In the description of the invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the invention can be understood according to specific circumstances.

[0042] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments.

[0043] refer to Figures 1 to 3 The present invention provides a semiconductor inspection device, including: a re-inspection light source 120 that emits re-inspection light, a bright field light source 100 that emits bright field light, and a dark field light source 110 that emits dark field light, the re-inspection light, the bright field light, and the dark field light are respectively guided to irradiate the surface of a chip 191, the re-inspection light is reflected by the chip 191 to form a re-inspection signal light, the bright field light is reflected by the chip 191 to form a bright field signal light, and the dark field light is scattered by the chip 191 to form a dark field signal light; an optical separation element 180, which is used to collect the bright field signal light, the dark field signal light, and the re-inspection signal light and perform spatial separation, so that the dark field signal light, the bright field signal light, and the re-inspection signal light are emitted to different transmission paths to form images respectively; wherein the dark field illumination spot formed by the dark field light on the surface of the chip 191, the bright field illumination spot formed by the bright field light on the surface of the chip 191, and the re-inspection illumination spot formed by the re-inspection light on the surface of the chip 191 do not overlap with each other.

[0044] Among them, the bright field light source 100, the dark field light source 110 and the re-inspection light source 120 are independent of each other, which solves the problem of limited wavelength selection in the detection process; the bright field signal light, the re-inspection signal light and the dark field signal light are independent of each other and do not overlap with each other, avoiding the splitting of the signal light to obtain the bright field signal light and the re-inspection signal light, which is beneficial to ensure that the bright field signal light and the re-inspection signal light with stronger intensity are obtained, and thus is beneficial to improving the detection accuracy.

[0045] The semiconductor inspection device provided by the embodiment of the present invention is used to perform defect inspection on a wafer 191 . In some examples, the wafer 191 may be a wafer with or without patterns.

[0046] In a specific embodiment, the distance between the two with the largest spacing among the dark field illumination spot, the bright field illumination spot, and the re-inspection illumination spot is greater than a first preset value and less than a second preset value. The first preset value may be in the range of 0.1 mm to 0.5 mm, and the second preset value may be in the range of 1 mm to 3 mm. In other words, the distance between the two with the largest spacing among the dark field illumination spot, the bright field illumination spot, and the re-inspection illumination spot will not be too far, nor too close. The advantage of such a setting is that if the distance is not too far, the difficulty of locating the same detection position is avoided during the switching process of bright field detection, dark field detection, and re-inspection, which is conducive to realizing rapid switching between different detection methods and improving detection efficiency; if the distance is not too close, it is conducive to ensuring that bright field detection, dark field detection, and re-inspection will not interfere with each other, which is conducive to improving detection accuracy.

[0047] In the semiconductor detection equipment provided by the embodiment of the present invention, it is ensured that the bright field illumination spot, the dark field illumination spot and the re-inspection illumination spot do not overlap with each other and the distance between them is not too far, which is beneficial to improving the detection efficiency and detection accuracy. On this basis, in order to realize the detection of bright field signal light, re-inspection signal light and dark field signal light with a short distance, the optical separation element 180 is used to spatially separate the bright field signal light, the dark field signal light and the re-inspection signal light, so that the corresponding signal light is received by the corresponding detector, thereby solving the problem of high difficulty in setting the detector due to the short distance between the bright field signal light, the re-inspection signal light and the dark field signal light.

[0048] In a specific embodiment, the re-inspection illumination spot is located between the dark field illumination spot and the bright field illumination spot, and the distance from the dark field illumination spot to the re-inspection illumination spot is the same as or different from the distance from the bright field illumination spot to the re-inspection illumination spot.

[0049] In a specific embodiment, referring to Figure 1 and Figure 2, the bright field signal light, the dark field signal light and the recheck signal light arrive at the optical separation element 180 along a common optical path, and the optical separation element 180 has a through hole 183, a first reflection surface 181 and a second reflection surface 182; the bright field signal light incident to the optical separation element 180 is reflected by the first reflection surface 181 and then emitted to the first transmission path, the dark field signal light incident to the optical separation element 180 is reflected by the second reflection surface 182 and then emitted to the second transmission path, and the recheck signal light incident to the optical separation element 180 passes through the through hole 183 and then emitted to the third transmission path. It should be noted that the extension direction of the first transmission path, the extension direction of the second transmission path and the extension direction of the third transmission path are all different. In some examples, the first transmission path and the second transmission path can extend in two opposite directions, and the extension direction of the third transmission path can be perpendicular to the extension direction of the first transmission path or the second transmission path.

[0050] In a specific embodiment, the semiconductor detection device further includes: a bright field detector 200, which is arranged in the first transmission path and is used to image the bright field signal light emitted by the optical separation element 180; a dark field detector 210, which is arranged in the second transmission path and is used to image the dark field signal light emitted by the optical separation element 180; and a re-inspection detector 220, which is arranged in the third transmission path and is used to image the re-inspection signal light emitted by the optical separation element 180. The bright field detector 200 is conjugate with the bright field illumination spot, the dark field detector 210 is conjugate with the dark field illumination spot, and the re-inspection detector 220 is conjugate with the re-inspection illumination spot.

[0051] In a specific embodiment, referring to Figure 2 The optical separation element 180 is a trapezoidal prism, and the through hole 183 passes through the top and bottom surfaces of the trapezoidal prism. The first reflection surface 181 and the second reflection surface 182 are respectively arranged on the two oblique side surfaces of the trapezoidal prism. The transmission direction of the dark field signal light, the transmission direction of the bright field signal light and the transmission direction of the re-inspection signal light emitted by the trapezoidal prism are all distributed in the same horizontal plane. In this way, the bright field detector 200, the dark field detector 210 and the re-inspection detector 220 can be arranged on the same horizontal platform surface to reduce the influence of the vibration of the horizontal platform surface on the imaging.

[0052] In a specific embodiment, the bright field light source 100 and the dark field light source 110 include continuous light sources for forming an efficient linear illumination spot (long strip light spot) on the surface of the chip; in some examples, a linear fiber-coupled bright field light source / dark field light source can be used as an illumination input end.

[0053] In some embodiments of the present invention, the bright field detector 200 and the dark field detector 210 include line scan cameras; in some examples, the bright field detector 200 and the dark field detector 210 are both integral delay line scan cameras, which are capable of maintaining high-resolution image capture capabilities even when the chip 191 moves at high speed, and are suitable for application scenarios in which the chip 191 moves continuously and rapidly for high-precision detection.

[0054] In some embodiments of the present invention, the re-inspection light source 120 includes a stroboscopic light source. Using the stroboscopic light source as the re-inspection light source 120 is conducive to alleviating the imaging smear phenomenon generated when re-inspecting the high-speed moving wafer 191. The specific description of using the stroboscopic light source for lighting to alleviate the smear problem of high-speed photography is as follows: In order to increase the speed during the re-inspection and re-shooting, the photography is usually performed during the movement, and the re-inspection camera is an area array camera. If the light source is a constant light source, due to the limited frequency of the area array camera, within the exposure time of a single frame of photography, the displacement caused by the movement is likely to produce a large smear, such as Figure 5 As shown in (a) in the figure; when a stroboscopic light source is used for re-inspection, the frequency of the light source will be higher than that of the array camera, that is, the stroboscopic time of the light source is very short, so the smear is small, as shown in Figure 5 As shown in (b) in the figure, the problem of ghosting can be alleviated. In some examples, the re-inspection light source 120 can be a stroboscopic high-brightness LED (light-emitting diode) light source; in some examples, the re-inspection illumination spot is circular; in other examples, the re-inspection illumination spot can also be shaped into a square or rectangle.

[0055] In some embodiments of the present invention, the re-inspection detector 220 includes a color area array camera, so that high-precision images can be collected with higher resolution and faster sensitivity, and more details and more accurate colors can be captured, which helps technicians identify defect features by observing color images.

[0056] In some embodiments of the present invention, the bright field illumination spot and the dark field illumination spot may both be long linear spots, and the re-inspection illumination spot may be a circular spot. Figure 4 The outermost circle represents the maximum field of view of the optical system. The maximum field of view refers to the field of view of the detector receiving bright field signal light, the field of view of the detector receiving dark field signal light, and the field of view of the detector receiving re-inspection signal light, which are combined according to their relative positions. The field of view of the detector receiving bright field signal light and the field of view of the detector receiving dark field signal light can be symmetrically distributed about the center of the maximum field of view, and the center of the field of view of the detector receiving re-inspection signal light can coincide with the center of the maximum field of view.

[0057] Figure 4The imaging field layout diagram shown is also equivalent to the illumination field schematic diagram. The bright field illumination spot and the dark field illumination spot can be symmetrically distributed about the center of the field of view, and the center of the re-inspection illumination spot can coincide with the center of the maximum field of view.

[0058] It should be noted that in order to ensure that the bright field detection and the dark field detection do not interfere with each other, it is necessary to ensure that the bright field illumination spot and the dark field illumination spot do not interfere with each other. Therefore, a spacing area needs to be maintained between the bright field illumination spot and the dark field illumination spot. The spacing area is used as an isolation area. The smaller the width d of the spacing area, the better. The theoretical value is 0. However, due to the influence of the aberration of the illumination light and the stray light, the bright field illumination spot and the dark field illumination spot will have a circle of halo or diffuse class. If the width d of the spacing area is 0, it is necessary to pay a great cost to make the surface of each related optical element clean enough without defects, and the illumination light path has no aberration. Therefore, for the consideration of engineering difficulty and cost, and also in order to introduce the re-inspection illumination spot, the width d of the spacing area needs to be reasonably set to ensure that the bright field detection and the dark field detection do not interfere with each other, and the re-inspection illumination spot can be added, and the bright field illumination area and the dark field illumination area will not be separated too far, resulting in a large imaging field of view. The preferred width d of the spacing area in the embodiment of the present invention is 0.2mm~2mm.

[0059] In a specific embodiment, referring to Figure 1 The semiconductor detection equipment also includes: an objective lens 160 and a spectroscopic element 150 arranged in sequence along a direction away from the chip 191, the re-inspection light and the bright field light are incident on the surface of the chip 191 through the spectroscopic element 150 and the objective lens 160 in sequence, the bright field signal light, the dark field signal light and the re-inspection signal light are incident on the optical separation element 180 through the objective lens 160 and the spectroscopic element 150 in sequence, and the bright field signal light, the dark field signal light and the re-inspection signal light are transmitted in a common optical path between the objective lens 160 and the optical separation element 180 and remain spatially isolated from each other.

[0060] In a specific embodiment, the semiconductor detection device also includes an imaging lens group 170, which is arranged between the spectroscopic element 150 and the optical separation element 180. The bright field signal light, dark field signal light and re-inspection signal light emitted from the spectroscopic element 150 are all incident on the optical separation element 180 through the imaging lens group 170. The imaging lens group 170 here can achieve a high-resolution imaging effect through different lens combinations, thereby forming an enlarged image on the corresponding detector.

[0061] In a specific embodiment, the spectroscopic element 150 includes a spectroscope, and the angle between the spectroscopic surface of the spectroscope facing the objective lens 160 and the horizontal direction is 45°. The imaging lens group 170, the bright field detector 200, the dark field detector 210 and the re-inspection detector 220 are arranged on the same horizontal platform to reduce the impact of platform vibration on imaging. The principle of reducing the impact of vibration by setting them on the same horizontal surface is as follows: usually, there will be a support and shock-absorbing structure under the table top used to set the imaging lens group 170, the bright field detector 200, the dark field detector 210 and the re-inspection detector 220. If the various components are set on the table top and arranged horizontally on the table top, then the center of gravity of each component is lower than the table top and can be better fixed to the table top; if the various components are arranged in the vertical direction, the overall center of gravity will be higher, and the components located on the upper layer cannot be directly fixed to the marble table top, and a supporting structure is required. In this way, the components on the upper layer are more susceptible to vibration. In summary, the embodiment of the present invention sets the imaging lens group 170, the bright field detector 200, the dark field detector 210 and the re-inspection detector 220 on the same horizontal surface, which is beneficial to reducing the impact of platform vibration on imaging.

[0062] In a specific embodiment, the target surface size of the bright field detector 200 is the same as the target surface size of the dark field detector 210, and the imaging field of view of the imaging lens assembly 170 satisfies the following formula:

[0063]

[0064] Among them, reference Figure 4 , D is the diameter of the imaging field of view, l is the target surface length, that is, the target surface length of the dark field detector 210, or the target surface length of the bright field detector 200, w is the target surface width, that is, the target surface width of the bright field detector 200, or the target surface width of the dark field detector 210, and d is the interval distance between the bright field illumination spot and the dark field illumination spot.

[0065] In a specific embodiment, the transmittance of the spectroscopic element 150 is in the range of 0 to 50%, and the reflectance of the spectroscopic element 150 is in the range of 50% to 100%. It can be understood that the retest light emitted by the retest light source 120 and the bright field light emitted by the bright field light source 100 can reach the objective lens 160 through the spectroscopic element 150, and the bright field signal light, dark field signal light and retest signal light emitted from the objective lens 160 can enter the subsequent transmission light path through the reflection of the spectroscopic element 150. Since the signal of the bright field detection is sufficient (that is, the light intensity of the bright field light is large), and the signal of the dark field detection is weak (the light intensity of the dark field light and the light intensity of the dark field signal light are both weak), the reflectance of the spectroscopic element 150 is large and the transmittance is small, so as to balance the light effect of the bright field detection and the light effect of the dark field detection.

[0066] In a specific embodiment, the semiconductor inspection device further includes a re-inspection illumination modulator mirror group 121 and an illumination mirror group 130 disposed between the re-inspection light source 120 and the light splitter 150. The re-inspection light emitted by the re-inspection light source 120 sequentially passes through the re-inspection illumination modulator mirror group 121 and the illumination mirror group 130 and is incident on the light splitter 150. It can be understood that the re-inspection illumination modulator mirror group 121 may include some optical elements such as relay lenses, filters, polarizers, and apertures to shape and modulate the re-inspection light.

[0067] In a specific embodiment, the illumination mirror group 130 is further arranged between the bright field light source 100 and the beam splitter 150, and the semiconductor detection device further comprises a bright field illumination modulator group 101, and the bright field light emitted by the bright field light source 100 sequentially passes through the bright field illumination modulator group 101 and the illumination mirror group 130 and is incident on the beam splitter 150. It can be understood that the bright field illumination modulator group 101 may include some optical elements such as relay lenses, filters, polarizers, and apertures, which are used to shape and modulate the bright field light.

[0068] That is to say, in some embodiments of the present invention, the re-inspection detection and the bright field detection share the illumination lens group 130, the spectroscopic element 150, the objective lens 160 and the imaging lens group 170. This is not only beneficial to reduce the cost of semiconductor detection equipment, but also beneficial to ensure that the bright field illumination spot and the re-inspection illumination spot are not too far apart.

[0069] In some embodiments of the present invention, the semiconductor inspection device further includes a first reflector group 122, and the re-inspection light emitted from the re-inspection illumination modulation mirror group 121 realizes an optical path deflection through the first reflector group 122, and then enters the illumination mirror group 130. By setting the first reflector group 122, the problem of position conflict between the bright field light source 100 and the re-inspection light source 120 caused by the bright field light and the re-inspection light sharing the illumination mirror group 130 can be solved. Of course, in some cases, the first reflector group 122 can be eliminated, and the re-inspection light can be directly transmitted to the illumination mirror group 130 using a light beam transmission device such as an optical fiber.

[0070] In some embodiments of the present invention, the semiconductor detection device further includes a second reflector group 140, which can be used to realize the optical path turning of the complex inspection light and the bright field light. Figure 1 and Figure 3The second reflector group 140 is arranged on the transmission optical path of the re-test light emitted from the illumination mirror group 130 and the bright field light emitted from the illumination mirror group 130. The re-test light and the bright field light are reflected by the second reflector group 140 and then the optical path is turned, and then the light is incident on the spectroscopic element 150. By setting the second reflector group 140 to achieve the optical path turning, the positions of various components in the semiconductor detection equipment can be reasonably arranged, which is conducive to reducing the overall volume of the semiconductor detection equipment. Of course, in some cases, the second reflector group 140 can also be eliminated, so that the re-test light and the bright field light are directly incident on the spectroscopic element 150.

[0071] For further reference, Figure 1 The objective lens 160 includes a plurality of sub-objective lenses 161, each of which has a different magnification. One of the plurality of sub-objective lenses 161 is located in the light beam transmission path between the beam splitting element 150 and the chip 191, and the sub-objective lens 161 located in the light beam transmission path is switchable. When performing bright field detection and dark field detection, the sub-objective lens 161 with a lower magnification can be switched to the light beam transmission path. When performing re-inspection, the sub-objective lens 161 with a higher magnification can be switched to the light beam transmission path for re-inspection imaging. The selected objective lens magnification needs to be flexibly configured according to actual needs, and is not specifically limited here.

[0072] In some embodiments of the present invention, the optical axis of the re-test light and the optical axis of the re-test signal light may both coincide with the system optical axis.

[0073] In a specific embodiment, referring to Figure 3 The semiconductor detection equipment also includes an automatic focusing module, which includes: an automatic focusing light source 230 and a dichroic mirror 231. The dichroic mirror 231 is arranged between the spectroscopic element 150 and the objective lens 160. The automatic focusing light source 230 is used to emit focusing light, and the focusing light is guided by the dichroic mirror 231 to irradiate the surface of the chip 191. The focusing light is reflected on the surface of the chip 191 to form focusing detection light. The focusing detection light reaches the automatic focusing module along the original optical path. The automatic focusing module can also include an imaging detector. The imaging detector collects spectral information or shape information of the focusing detection light. Based on this information, the position of the chip 191 relative to the front focal plane of the objective lens can be determined. In addition, the wavelength of the focused light is 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. In this way, the dichroic mirror 231 can be used to reflect the focused light and transmit the re-inspection light, the bright field light, the dark field signal light, the bright field signal light, and the re-inspection signal light, which can not only ensure that the focused light is incident on the surface of the chip 191 through the objective lens 160, but also avoid the automatic focusing module from affecting the re-inspection, bright field detection, and dark field detection. It can be understood that the position of the chip 191 is measured in real time by the automatic focusing module, and the chip 191 is adjusted to the front focal plane of the objective lens to be in a focused state, so that the chip can be initially inspected and re-inspected.

[0074] In some embodiments of the present invention, the automatic focusing module can use a detection light beam in the red band as the focusing light. In some examples, a detection light beam with a wavelength in the range of 650nm to 700nm is preferably used as the focusing light. The spectrum of the detection light (re-inspection light, bright field light, dark field signal light, bright field signal light and re-inspection signal light) is preferably in the band of 400nm to 650nm. The dichroic mirror 231 can reflect light beams in the band above 650nm and transmit light with a wavelength below 650nm, so that the focusing light and the detection light of the automatic focusing module do not interfere with each other.

[0075] Furthermore, the semiconductor inspection device also includes a dark field illumination modulation mirror group 111 cooperating with the dark field light source 110 , and the dark field light emitted by the dark field light source 110 is incident on the surface of the chip 191 through the dark field illumination modulation mirror group 111 .

[0076] It should be noted that the dark field illumination modulation mirror group 111, the bright field illumination modulation mirror group 101, the re-inspection illumination modulation mirror group 121, the imaging mirror group 170 and the illumination mirror group 130 involved in the embodiments of the present invention are all used to realize optical modulation of the light beam, and the optical modulation includes but is not limited to collimation, filtering and focusing.

[0077] In a specific embodiment, the semiconductor testing device further includes a carrier 190, and the carrier 190 has a carrier surface for carrying a wafer 191. In some examples, the carrier 190 is an electric translation stage, which can carry the wafer 191 horizontally and move it in the XYZ directions.

[0078] Below Figure 1 The semiconductor testing device shown is taken as an example to further illustrate the working principle of the semiconductor testing device provided by the present invention.

[0079] refer to Figure 1 When re-inspection is performed, the re-inspection light emitted by the re-inspection light source 120 enters the illumination lens group 130 through the re-inspection illumination modulation lens group 121 and the first reflection lens group 122, and then evenly illuminates the pupil surface of the objective lens 160 after passing through the second reflection lens group 140 and the beam splitter element 150. A re-inspection illumination light spot with uniform brightness is formed on the surface of the chip 191 through the objective lens 160. A partial area on the chip 191 is illuminated by the re-inspection light and then emits a re-inspection signal light. The re-inspection signal light passes through the objective lens 160 and is reflected by the beam splitter element 150 and then enters the imaging lens group 170. The re-inspection signal light emitted by the imaging lens group 170 is incident on the optical separation element 180, and enters the imaging tube lens of the re-inspection detector 220 through the through hole 183 of the optical separation element 180 to realize re-inspection imaging.

[0080] Continue to refer Figure 1When performing bright field detection, the bright field light source 100 emits bright field light, which enters the illumination mirror group 130 through the bright field illumination modulation mirror group 101. The beam path of the bright field light entering the illumination mirror group 130 has an offset distance relative to the beam path of the re-test light entering the illumination mirror group 130. The bright field light emitted from the illumination mirror group 130 is turned by the second reflection mirror group 140, and then passes through the beam splitter 150 and the objective lens 160 to form a bright field illumination with uniform brightness on the surface of the chip 191. Light spot: Because the bright field light transmitted along the common optical path is offset relative to the re-inspection light, the bright field illumination light spot is also offset relative to the center of the objective lens 160. After part of the surface of the chip 191 is illuminated by the bright field light, bright field signal light is reflected. The bright field signal light passes through the objective lens 160 and enters the imaging lens group 170 after being reflected by the spectrometer 150, and is then collected by the optical separation element 180. After being reflected by the optical separation element 180, it is received by the bright field detector 200 and bright field imaging is performed.

[0081] Continue to refer Figure 1 The dark field light source 110 is an external light source. When performing dark field detection, the dark field light emitted by the dark field light source 110 is incident on the surface of the chip 191 through the dark field illumination modulation lens group 111, and a dark field illumination spot is formed on the chip 191, which deviates from the imaging field center of the objective lens 160 and is symmetrically distributed with the bright field illumination spot about the imaging field center of the objective lens 160. After part of the surface of the chip 191 is illuminated by the dark field light, dark field signal light is scattered. The dark field signal light passes through the objective lens 160 and enters the imaging lens group 170 after being reflected by the beam splitting element 150, and is then collected by the optical separation element 180. After being reflected by the optical separation element 180, it is received by the dark field detector 210 and dark field imaging is performed.

[0082] It should be noted that the inspection process of the chip in the present invention can be divided into initial inspection and re-inspection, wherein the initial inspection includes bright field inspection and dark field inspection, and the inspection is performed simultaneously without interfering with the imaging. The objective lens with a lower magnification can be switched to the optical path to cooperate with the bright field inspection and the dark field inspection. When the re-inspection is performed after the bright field inspection and the dark field inspection are completed, the objective lens with a higher magnification can be switched to the optical path to cooperate with the re-inspection. Of course, in some cases, the initial inspection and re-inspection can also be performed at the same time, such as selecting an objective lens with a suitable magnification to switch to the optical path, and performing bright field inspection, dark field inspection and re-inspection at the same time. Since the illumination and imaging are separated from each other, the three can be made to not interfere with each other, which can greatly improve the inspection efficiency.

[0083] In summary, based on the bright field detection, dark field detection and re-inspection performed by the semiconductor detection equipment provided in the embodiment of the present invention, each field of view is separated, and the re-inspection optical path is integrated, which is conducive to improving the detection speed; the re-inspection optical path adopts a separate re-inspection light source 120, and a stroboscopic light source is used to solve the imaging smear problem caused by the rapid movement of the chip 191 during the re-inspection; the bright field signal light, dark field signal light and re-inspection signal light are separated by an isosceles trapezoidal prism with a central opening (optical separation element 180), and then received by the corresponding detector, which solves the problem of the signal light becoming weaker after splitting due to the use of a splitter prism and the like.

[0084] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the disclosure of the present invention can be performed in parallel, sequentially or in different orders, as long as the desired results of the technical solution disclosed in the present invention can be achieved, and this document does not limit this.

[0085] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A semiconductor testing device, characterized in that: include: A retest light source emitting retest light, a bright field light source emitting bright field light, and a dark field light source emitting dark field light, wherein the retest light, the bright field light, and the dark field light are respectively guided to illuminate the surface of the wafer, the retest light is reflected by the wafer to form retest 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, used for collecting the bright field signal light, the dark field signal light and the recheck signal light and performing spatial separation, so that the dark field signal light, the bright field signal light and the recheck signal light are emitted to different transmission paths for respective imaging; The dark field illumination spot formed by the dark field light on the wafer surface, the bright field illumination spot formed by the bright field light on the wafer surface, and the re-inspection illumination spot formed by the re-inspection light on the wafer surface do not overlap with each other.

2. The semiconductor testing device according to claim 1, characterized in that: The distance between the two with the largest spacing among the dark field illumination spot, the bright field illumination spot and the re-inspection illumination spot is greater than a first preset value and less than a second preset value, the first preset value is in the range of 0.1 mm to 0.5 mm, and the second preset value is in the range of 1 mm to 3 mm.

3. The semiconductor testing device according to claim 1 or 2, characterized in that: The re-inspection illumination spot is located between the dark field illumination spot and the bright field illumination spot, and the distance from the dark field illumination spot to the re-inspection illumination spot is the same as or different from the distance from the bright field illumination spot to the re-inspection illumination spot.

4. The semiconductor testing device according to claim 1, characterized in that: The bright field signal light, the dark field signal light and the re-test signal light arrive at the optical separation element along a common optical path, and the optical separation element has a through hole, a first reflection surface and a second reflection surface; The bright field signal light incident to the optical separation element is reflected by the first reflection surface and then emitted to the first transmission path, the dark field signal light incident to the optical separation element is reflected by the second reflection surface and then emitted to the second transmission path, and the re-inspection signal light incident to the optical separation element is emitted to the third transmission path through the through hole.

5. The semiconductor testing device according to claim 4, characterized in that: The semiconductor testing equipment further comprises: a bright field detector, the bright field detector being arranged in the first transmission path and being used for imaging the bright field signal light emitted by the optical separation element; a dark field detector, which is arranged on the second transmission path and is used to image the dark field signal light emitted by the optical separation element; A re-check detector is provided in the third transmission path and is used for imaging the re-check signal light emitted by the optical separation element.

6. The semiconductor testing device according to claim 5, characterized in that: The optical separation element is a trapezoidal prism, the through hole passes through the top surface and the bottom surface of the trapezoidal prism, the first reflecting surface and the second reflecting surface are respectively arranged on the two inclined side surfaces of the trapezoidal prism, the transmission direction of the dark field signal light emitted by the trapezoidal prism, the transmission direction of the bright field signal light and the transmission direction of the re-inspection signal light are all distributed in the same horizontal plane, and the bright field detector, the dark field detector and the re-inspection detector are arranged on the same horizontal platform surface to reduce the influence of the vibration of the horizontal platform surface on imaging.

7. The semiconductor testing device according to claim 5, characterized in that: The bright field light source and the dark field light source include continuous light sources; the re-inspection light source includes a stroboscopic light source; the bright field detector and the dark field detector include line scan cameras; and the re-inspection detector includes a color array camera.

8. The semiconductor testing device according to claim 5, characterized in that: The semiconductor detection equipment also includes: an objective lens and a spectroscopic element arranged in sequence along a direction away from the chip, the re-inspection light and the bright field light are incident on the chip surface through the spectroscopic element and the objective lens in sequence, the bright field signal light, the dark field signal light and the re-inspection signal light are incident on the optical separation element through the objective lens and the spectroscopic element in sequence, and the bright field signal light, the dark field signal light and the re-inspection signal light are transmitted in a common optical path between the objective lens and the optical separation element and remain spatially isolated from each other.

9. The semiconductor testing device according to claim 8, characterized in that: The semiconductor detection equipment also includes an imaging mirror group, which is arranged between the spectroscopic element and the optical separation element. The bright field signal light, the dark field signal light and the re-inspection signal light emitted from the spectroscopic element all pass through the imaging mirror group and are incident on the optical separation element.

10. The semiconductor testing device according to claim 9, characterized in that: The beam splitter element comprises a beam splitter, the angle between the beam splitter surface facing the objective lens and the horizontal direction is 45°, and the imaging lens group, the bright field detector, the dark field detector and the re-inspection detector are arranged on the same horizontal platform.

11. The semiconductor testing device according to claim 9, characterized in that: The target surface size of the bright field detector is the same as that of the dark field detector, and the imaging field of view of the imaging lens assembly satisfies the following formula: Wherein, D is the diameter of the imaging field of view, l is the length of the target surface, w is the width of the target surface, and d is the distance between the bright field illumination spot and the dark field illumination spot.

12. The semiconductor testing device according to claim 8, characterized in that: The transmittance of the light splitting element is in the range of 0 to 50%, and the reflectance of the light splitting element is in the range of 50 to 100%.

13. The semiconductor testing device according to claim 8, characterized in that: The semiconductor inspection device also includes a re-inspection illumination modulation mirror group and an illumination mirror group arranged between the re-inspection light source and the spectroscopic element. The re-inspection light emitted by the re-inspection light source passes through the re-inspection illumination modulation mirror group and the illumination mirror group in sequence and is incident on the spectroscopic element.

14. The semiconductor testing device according to claim 13, characterized in that: The illumination mirror group is also arranged between the bright field light source and the spectroscopic element. The semiconductor detection equipment also includes a bright field illumination modulation mirror group. The bright field light emitted by the bright field light source passes through the bright field illumination modulation mirror group and the illumination mirror group in sequence and is incident on the spectroscopic element.

15. The semiconductor testing device according to claim 8, characterized in that The objective lens includes a plurality of sub-objective lenses, each of which has a different magnification. One of the plurality of sub-objective lenses is located in a light beam transmission path between the beam splitting element and the chip, and the sub-objective lens located in the light beam transmission path is switchable.

16. The semiconductor testing device according to claim 8, characterized in that The semiconductor detection equipment also includes an automatic focusing module, which includes: an automatic focusing light source and a dichroic mirror, wherein the dichroic mirror is arranged between the spectroscopic element and the objective lens, and the automatic focusing light source is used to emit focused light, and the focused light is guided by the dichroic mirror to irradiate the surface of the chip, and the wavelength of the focused light is 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.

17. The semiconductor testing device according to claim 1, characterized in that: The semiconductor detection equipment further includes a dark field illumination modulation mirror group cooperating with the dark field light source, and the dark field light emitted by the dark field light source is incident on the wafer surface through the dark field illumination modulation mirror group.

18. The semiconductor testing device according to claim 1, characterized in that: The semiconductor testing device further comprises a carrying platform, wherein the carrying platform has a carrying surface for carrying a wafer.

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