Wafer detection device

Abstract

The invention provides a wafer detection device. The wafer detection device comprises a light source, wherein the light source emits initial light to a wafer to enable the wafer to emit scattered light beams; the first reflecting mirror is positioned on one side, facing the light source, of the wafer and reflects at least part of the scattered light beam into a first reflecting light beam; the first lens group is located on the side, away from the wafer, of the first reflector and adjusts the first reflection light beam into a first adjustment light beam, and the divergence angle of the first adjustment light beam is smaller than that of the first reflection light beam; and the first detector is arranged on one side, far away from the wafer, of the first lens group and receives the first adjusting light beam. Therefore, the obtained surface image of the wafer is clearer, the distinguished minimum particle size can be smaller, the detection sensitivity of the wafer detection device is higher, and small-size defects can be better detected.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular to a wafer detection device. Background Art

[0002] High-purity single-crystal silicon wafers are the basis for the production of electronic devices in the semiconductor industry. Defects will be introduced on the wafer surface at each stage of chip manufacturing. Therefore, in multiple steps of chip production, wafer inspection devices are required to detect the types and number of defects introduced by the current production steps. The chip production process mainly includes substrate epitaxy, front-end and back-end. Among them, the front-end process is an important guarantee for chip yield, and the technical threshold of the equipment is high and the verification cycle is long. There are three main types of defects that need to be monitored in the front-end process. The first type of defect is due to the random appearance of voids during crystal growth, resulting in pits on the wafer surface (crystal originated pits, hereinafter referred to as COP), and the size of COP is between 100nm and 200nm. The second type of defect is particles attached to the wafer surface and introduced by the external environment, including organic or metal particles introduced by processes such as engineer operation and equipment operation. The third type of defect is defects introduced during wafer polishing, such as residues, stains, pits, scratches, surface particles, etc. The above three types of wafer surface defects will greatly damage the performance of microelectronic devices processed with silicon wafers as substrates. Therefore, in order to better detect wafer surface defects, a highly sensitive wafer detection device is required.

[0003] The wafer inspection device includes a light source and a detector. The light emitted by the light source irradiates the wafer, and the wafer scatters the light to a certain extent. The detector obtains information about the wafer surface by capturing the scattered light, that is, it detects defects on the wafer surface. However, the existing wafer inspection device has poor detection capabilities for small-sized defects. Summary of the invention

[0004] In order to at least partially solve the problems existing in the prior art, according to one aspect of the present invention, a wafer detection device is provided. The wafer detection device includes: a light source, the light source emits initial light to the wafer so that the wafer emits a scattered light beam; a first reflector, the first reflector is located on the side of the wafer facing the light source and reflects at least part of the scattered light beam into a first reflected light beam; a first lens group, the first lens group is located on the side of the first reflector away from the wafer and adjusts the first reflected light beam into a first adjustment light beam, the divergence angle of the first adjustment light beam is smaller than the divergence angle of the first reflection light beam; and a first detector, the first detector is arranged on the side of the first lens group away from the wafer and receives the first adjustment light beam.

[0005] The wafer detection device provided by the present application forms an object-image mapping from the wafer to the first detector through the first lens group, and the divergence angle of the first adjustment light beam is smaller than the divergence angle of the first reflection light beam, so that the imaging resolution of the first detector is higher. In this way, the surface image of the obtained wafer is clearer, the minimum particle size that can be resolved can be smaller, the detection sensitivity of the wafer detection device is higher, and small-sized defects can be better detected.

[0006] Exemplarily, a first aperture is disposed between the first lens group and the first reflector.

[0007] Exemplarily, there is a first distance D1 between the first aperture and the first lens group, and D1 is 2.5 mm to 3.5 mm.

[0008] Exemplarily, there is a second distance D2 between the first aperture and the first reflector, and D2 is 240 mm to 248 mm.

[0009] Exemplarily, the first lens group includes a first lens and a second lens, the first lens is closer to the first reflector than the second lens, the first lens adjusts the first reflected light beam into a first parallel light beam, and the second lens adjusts the first parallel light beam into a first adjusted light beam.

[0010] Exemplarily, a side of the first lens facing the first reflector is a planar structure, and a side of the first lens facing away from the first reflector is a convex structure.

[0011] Exemplarily, a side of the second lens facing the first reflector is a convex structure and a side of the second lens facing away from the first reflector is a planar structure.

[0012] Exemplarily, the center thickness of the first lens is 11 mm to 13 mm.

[0013] Exemplarily, the center thickness of the second lens is 7.0 mm to 7.4 mm.

[0014] Exemplarily, there is a third distance D3 between the first lens and the second lens, and D3 is 13 mm to 17 mm.

[0015] Exemplarily, there is a fourth distance D4 between the second lens and the first detector, and D4 is 4.5 mm to 4.7 mm.

[0016] Exemplarily, the first reflector includes an ellipsoid reflector, and a projection of the ellipsoid reflector in the plane where the wafer is located surrounds the wafer.

[0017] Exemplarily, the ellipsoidal reflector is formed with a first focus and a second focus, at least a portion of the structure of the wafer coincides with the first focus, and the first lens group is located between the second focus and the first detector.

[0018] Exemplarily, the wafer inspection device also includes a second lens group, a second reflector and a second detector. The second lens group is located on the side of the wafer facing the light source and adjusts part of the scattered light beam into a second adjusted light beam. The divergence angle of the second adjusted light beam is smaller than the divergence angle of the part of the scattered light beam incident on the second lens group. The second reflector is located on the side of the second lens group away from the wafer and reflects the second adjusted light beam into a second reflected light beam. The second detector is arranged on the side of the second reflector facing the wafer and receives the second reflected light beam.

[0019] Exemplarily, the second lens group includes a third lens, a fourth lens, and a fifth lens located between the third lens and the fourth lens, the third lens is closer to the wafer than the fourth lens, the third lens adjusts the scattered light beam into a second parallel light beam, the fourth lens adjusts the second parallel light beam into a divergent light beam, and the fifth lens adjusts the divergent light beam into a second adjusted light beam.

[0020] Exemplarily, a side of the third lens facing the wafer is a planar structure, and a side of the third lens facing the second reflector is a convex structure.

[0021] Exemplarily, a side of the fifth lens facing the wafer is a planar structure, and a side of the fifth lens facing the second reflector is a concave structure.

[0022] Exemplarily, the side of the fourth lens facing the wafer and the side facing the second reflector are both convex structures.

[0023] Exemplarily, the third lens is a single convex lens and the side facing the second reflector is a spherical structure with a curvature radius of 15.9 mm to 16.2 mm.

[0024] Exemplarily, the fifth lens is a single concave lens and the side facing the second reflector is a concave spherical structure with a curvature radius of 67 mm to 71 mm.

[0025] Exemplarily, the fourth lens is a double convex lens, and the side of the fourth lens facing the wafer and the side facing the second reflector are both spherical structures with the same curvature radius, which is 67 mm to 71 mm.

[0026] Exemplarily, the thickness of the third lens is 4.8 mm to 5.2 mm.

[0027] Exemplarily, the thickness of the fifth lens is 2.4 mm to 2.6 mm.

[0028] Exemplarily, the thickness of the fourth lens is 4.77 mm to 4.97 mm.

[0029] Exemplarily, there is a fifth distance D5 between the third lens and the wafer, and D5 is 24 mm to 26 mm.

[0030] Exemplarily, there is a sixth distance D6 between the fourth lens and the second reflector, and D6 is 80 mm to 82 mm.

[0031] Exemplarily, there is a seventh distance D7 between the second reflector and the second detector, and D7 is 139 mm to 140 mm.

[0032] Exemplarily, there is an eighth distance D8 between the third lens and the fifth lens, and D8 is 7 mm to 9 mm.

[0033] Exemplarily, there is a ninth distance D9 between the fifth lens and the fourth lens, and D9 is 3.5 mm to 4.5 mm.

[0034] Exemplarily, a second aperture is arranged between the second reflector and the second detector.

[0035] Exemplarily, the angle between the scattered light beam adjusted by the second lens group and the normal line of the wafer is 0-10°.

[0036] Exemplarily, the angle between the scattered light beam reflected by the first reflector and the normal line of the wafer is 15° to 83°.

[0037] A series of simplified concepts are introduced in the summary of the invention, which will be further described in detail in the detailed description. The summary of the invention is not intended to limit the key features and essential technical features of the claimed technical solution, nor is it intended to determine the scope of protection of the claimed technical solution.

[0038] The advantages and features of the present invention are described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The following drawings of the present invention are used as part of the present invention for understanding the present invention. The embodiments of the present invention and their description are shown in the drawings to explain the principle of the present invention. In the drawings,

[0040] Figure 1 is a cross-sectional view of a wafer inspection device according to an exemplary embodiment of the present invention;

[0041] Figure 2 is a schematic structural diagram of a first lens group, a first reflector, and a first detector according to an exemplary embodiment of the present invention;

[0042] Figure 3 is a schematic structural diagram of a second lens group, a second reflector and a second detector according to an exemplary embodiment of the present invention, wherein: Figure 1 , Figure 2 and Figure 3 The optical paths are schematically shown in FIG.

[0043] The above drawings include the following reference numerals:

[0044] 10. Wafer detection device; 110. Light source; 1110. First reflector; 1120. First lens group; 1121. First lens; 1122. Second lens; 1130. First detector; 1140. First aperture; 1150. First polarizer; 1160. First filter; 1210. Second reflector; 1220. Second lens group; 1221. Third lens; 1222. Fourth lens; 1223. Fifth lens; 1230. Second detector; 1240. Second aperture; 1250. Second filter; 20. Wafer. DETAILED DESCRIPTION

[0045] In the following description, a large amount of details are provided so that the present invention can be thoroughly understood. However, it will be appreciated by those skilled in the art that the following description only exemplarily illustrates a preferred embodiment of the present invention, and the present invention can be implemented without one or more such details. In addition, in order to avoid confusion with the present invention, some technical features well known in the art are not described in detail.

[0046] In order to fully understand the embodiments of the present invention, detailed structures will be presented in the following description. Obviously, the implementation of the embodiments of the present invention is not limited to the specific details familiar to those skilled in the art. The preferred embodiments of the present invention are described in detail below, but in addition to these detailed descriptions, the present invention may also have other embodiments.

[0047] An embodiment of the present invention provides a wafer inspection device. The wafer inspection device can be used to detect surface defects of a wafer. Figure 1 and Figure 2, the wafer detection device 10 may include a light source 110, a first reflector 1110, a first lens group 1120 and a first detector 1130. The light source 110 may emit initial light to the wafer 20 so that the wafer 20 emits a scattered light beam. The light source 110 may emit initial light perpendicular to and / or inclined to the wafer 20. The light emitted by the light source 110 may be reflected by the reflector and directed to the wafer 20. The light source 110 may use a 355nm laser. The first reflector 1110 may be located on a side of the wafer 20 facing the light source 110 and reflect at least part of the scattered light beam into a first reflected light beam. The first lens group 1120 may be located on a side of the first reflector 1110 away from the wafer 20 and adjust the first reflected light beam into a first adjusted light beam, wherein the divergence angle of the first adjusted light beam is less than the divergence angle of the first reflected light beam. The first detector 1130 is disposed on a side of the first lens group 1120 away from the wafer 20 and receives the first adjusted light beam. The initial light is directed to the wafer 20, and reflection and scattering will occur on the wafer 20, wherein at least part of the scattered light beam generated by scattering is directed to the first reflector 1110, and the direction of the light beam is changed to become the first reflected light beam under the action of the first reflector 1110, and the first reflected light beam passes through the first lens group 1120, and the first lens group 1120 converges the first reflected light beam to a certain extent to become the first adjusted light beam, and the first adjusted light beam is directed to the first detector 1130, that is, the object image mapping from the wafer 20 to the first detector 1130 is formed, and the surface defects of the wafer 20 can be detected. The first reflected light beam is adjusted to the first adjusted light beam through the first lens group 1120, and the divergence angle becomes smaller, that is, the divergence angle of the first adjusted light beam received by the first detector 1130 is smaller. In this way, by reducing the divergence angle, the numerical aperture is correspondingly reduced. Under the condition that the wavelength remains unchanged, the distance between the two object points that can be distinguished is smaller, smaller particles can be distinguished, and the resolution of the imaging is higher. By reasonably setting the first lens group 1120, the minimum size of the distinguishable particles can reach 30nm.

[0048] The wafer inspection device 10 provided by the present application forms an object-image mapping from the wafer 20 to the first detector 1130 through the first lens group 1120, and the divergence angle of the first adjustment light beam is smaller than the divergence angle of the first reflection light beam, so that the imaging resolution of the first detector 1130 is higher. In this way, the surface image of the wafer 20 obtained is clearer, the minimum particle size that can be resolved can be smaller, the detection sensitivity of the wafer inspection device 10 is higher, and small-sized defects can be better detected.

[0049] For example, in conjunction with reference Figure 1 and Figure 2A first aperture 1140 may be provided between the first lens group 1120 and the first reflector 1110. That is, the first aperture 1140 is on the optical path of the first reflected light beam. The first reflected light beam passes through the first aperture 1140 before entering the first lens group 1120. The setting of the first aperture 1140 can filter out the interfering light waves in the first reflected light beam and has the effect of eliminating noise, that is, improving the ratio of the optical signal power to the noise power of the imaging of the first detector 1130, further enabling the first detector 1130 to distinguish smaller particles and improve the imaging resolution.

[0050] For example, refer to Figure 2 , there may be a first distance D1 between the first aperture 1140 and the first lens group 1120, and D1 may be 2.5 mm to 3.5 mm. For example, D1 may be 2.5 mm, 3 mm, or 3.5 mm, etc. With this arrangement, the distance between the first aperture 1140 and the first lens 1121 is more moderate, the imaging resolution is higher, and the detection is more sensitive. In the embodiment where the first lens group 1120 includes the first lens 1121 and the second lens 1122, the first distance may also be understood as the distance between the first aperture 1140 and the first lens 1121.

[0051] For example, refer to Figure 2 , there may be a second distance D2 between the first aperture 1140 and the first reflector 1110, and D2 may be 240 mm to 248 mm. For example, D2 may be 240 mm, 244 mm, or 248 mm. Among them, the distance between the first aperture 1140 and the first reflector 1110 may be understood as the distance in the XX direction between one end of the first aperture 1140 close to the first reflector 1110 and one end of the first reflector 1110 close to the first aperture 1140. This arrangement can reduce the aberration of the imaging, provide better imaging effects, and make the detection results more accurate.

[0052] For example, refer to Figure 2 , the first lens group 1120 may include a first lens 1121 and a second lens 1122. The first lens 1121 may be closer to the first reflector 1110 than the second lens 1122. The first lens 1121 may adjust the first reflected light beam to be a first parallel light beam, and the second lens 1122 may adjust the first parallel light beam to be a first adjusted light beam. In other words, the first reflected light beam passes through the first lens 1121 and the second lens 1122 in sequence. The first lens 1121 collimates the first reflected light beam to become a first parallel light beam, and the second lens 1122 converges the first parallel light beam to become a first adjusted light beam and project to the first detector 1130. In this way, under the premise of ensuring good detection sensitivity, the structure of the first lens group 1120 is simpler and the light loss is less.

[0053] For example, refer to Figure 2 , the side of the first lens 1121 facing the first reflector 1110 may be a planar structure and the side away from the first reflector 1110 may be a convex structure. Exemplarily, the side of the second lens 1122 facing the first reflector 1110 may be a convex structure and the side away from the first reflector 1110 may be a planar structure. That is, at least one of the first lens 1121 and the second lens 1122 is a single convex lens. The first lens 1121 and the second lens 1122 arranged in this way have a simpler structure and can better control the imaging effect.

[0054] Exemplarily, the side of the first lens 1121 facing the first reflector 1110 may be an eighth-order even-order aspheric structure, specifically, the radius of curvature may be 12.31 mm, the fourth-order aspheric coefficient may be 9.41, the sixth-order aspheric coefficient may be 1.65, and the eighth-order aspheric coefficient may be 2.77.

[0055] Exemplarily, the side of the second lens 1122 facing the first reflector 1110 may be a sixth-order even-order aspheric surface. Specifically, the radius of curvature may be 23.81 mm, the fourth-order aspheric coefficient may be 8.347, and the sixth-order aspheric coefficient may be 2.649.

[0056] Exemplarily, the center thickness of the first lens 1121 may be 11 mm to 13 mm. For example, the center thickness of the first lens 1121 may be 11 mm, 12 mm or 13 mm. The center thickness of the first lens 1121 may be understood as the thickness of the thickest part of the first lens 1121. In the embodiment where one side of the first lens 1121 is a convex structure and the other side is a plane structure, the center thickness is the vertical distance from the convex vertex to the plane side. Exemplarily, the center thickness of the second lens 1122 may be 7.0 mm to 7.4 mm. For example, the center thickness of the second lens 1122 may be 7.0 mm, 7.2 mm or 7.4 mm. The center thickness of the second lens 1122 may be understood as the thickness of the thickest part of the second lens 1122. In the embodiment where one side of the second lens 1122 is a convex structure and the other side is a plane structure, the center thickness is the vertical distance from the convex vertex to the plane side. The first lens 1121 and / or the second lens 1122 set in this way have smaller aberrations, which can better ensure the imaging effect and detection sensitivity.

[0057] For example, refer to Figure 2, there may be a third distance D3 between the first lens 1121 and the second lens 1122, and D3 may be 13 mm to 17 mm. For example, D3 may be 13 mm, 15 mm, or 17 mm, etc. In this way, the first lens group 1120 can be better imaged on the first detector 1130 to ensure detection sensitivity. Exemplarily, there is a fourth distance D4 between the second lens 1122 and the first detector 1130, and D4 is 4.5 mm to 4.7 mm. For example, D4 ​​may be 4.50 mm, 4.59 mm, or 4.7 mm, etc. The fourth distance can also be understood as the distance between the first lens group 1120 and the first detector 1130. With this arrangement, the imaging resolution is higher and the detection sensitivity is better.

[0058] For example, in conjunction with reference Figure 1 and Figure 2 , the first reflector 1110 may include an ellipsoidal reflector, and the projection of the ellipsoidal reflector in the plane where the wafer 20 is located surrounds the wafer 20. Specifically, the inner side of the ellipsoidal reflector is ellipsoidal and reflects part of the scattered light beam. Taking the illustrated embodiment as an example, the ellipsoidal reflector is located on the side of the wafer 20 facing the light source 110 in the XX direction, and the ellipsoidal reflector is located on the outside of the wafer 20 in the YY direction and surrounds the wafer 20. The setting of the ellipsoidal reflector can better control the path of light reflection and convergence, thereby optimizing the imaging effect. The scattered light beams scattered in different directions on the wafer 20 can all be projected to the ellipsoidal reflector, so that the ellipsoidal reflector can reflect more scattered light and make the first reflected light beam projected toward the first lens group 1120.

[0059] For example, in conjunction with reference Figure 1 and Figure 2 , the ellipsoidal reflector may be formed with a first focus and a second focus, at least a portion of the structure of the wafer 20 may coincide with the first focus, and the first lens group 1120 may be located between the second focus and the first detector 1130. This arrangement can better ensure the adjustment effect of the first lens group 1120 on the first reflected light beam, thereby ensuring the imaging effect. The first focus coincides with at least a portion of the structure of the wafer 20, and the information of the surface defects of the wafer 20 can be better obtained. Exemplarily, the center of the wafer 20 may coincide with the first focus. In an embodiment in which the first aperture 1140 is provided, the first aperture 1140 may also be located between the second focus and the first detector 1130. Further, the distance between the first lens group 1120 and the second focus may be smaller than the distance between the first reflector 1110 and the second focus, so that as many first reflected light beams as possible can pass through the first lens group 1120. In some embodiments, the first aperture may be correspondingly arranged at the second focus.

[0060] For example, refer to Figure 2, the first reflector 1110 may have a length L1 in the XX direction, and L1 may be 96 mm to 100 mm. For example, L1 may be 96 mm, 98.8 mm, or 100 mm, etc. Exemplarily, the wafer 20 and the first reflector 1110 may have a distance L2 in the XX direction, and L2 may be 10 mm to 11 mm. For example, L2 is 10 mm, 10.5 mm, or 11 mm, etc. In an embodiment in which the first reflector 1110 includes an ellipsoidal reflector, the radius of curvature of the ellipsoidal reflector may be 20 mm to 23 mm. For example, the radius of curvature of the ellipsoidal reflector is 20 mm, 21.229 mm, or 23 mm, etc. By setting the structure and position of the first reflector 1110, the scattered light beam can be better reflected, and the first reflected light beam can be directed to the first lens group 1120.

[0061] For example, in conjunction with reference Figure 1 and Figure 2 A first polarizer 1150 may be further disposed between the first aperture 1140 and the first detector 1130. A first filter 1160 may be further disposed between the first aperture 1140 and the first detector 1130, and the first filter 1160 may be disposed on a side of the first polarizer 1150 facing the first detector 1130. Schematically, a first attenuation plate may be further disposed between the first aperture 1140 and the first detector 1130.

[0062] According to the difference in the angle between the scattered light beam and the normal line of the wafer 20, it can be divided into a wide channel scattered light beam and a narrow channel scattered light beam. The angle between the wide channel scattered light beam and the normal line of the wafer 20 is greater than the angle between the narrow channel scattered light beam and the normal line of the wafer 20. The scattered light beam reflected by the first reflector 1110 can be understood as a wide channel scattered light beam. The wafer 20 detection device provided in the present application also includes a structural member for adjusting the narrow channel scattered light beam. For example, in combination with reference Figure 1 and Figure 3The wafer inspection device 10 may further include a second lens group 1120, a second reflector 1210, and a second detector 1230. The second lens group 1120 may be located on the side of the wafer 20 facing the light source 110 and adjust the part of the scattered light beam into a second adjustment light beam, and the divergence angle of the second adjustment light beam is smaller than the divergence angle of the part of the scattered light beam incident on the second lens group 1120. The second reflector 1210 may be located on the side of the second lens group 1120 away from the wafer 20 and reflect the second adjustment light beam into a second reflected light beam, and the second detector 1230 may be arranged on the side of the second reflector 1210 facing the wafer 20 and receive the second reflected light beam. The divergence angle of the second adjustment light beam is small, so that the imaging resolution of the second detector 1230 is higher. In this way, the surface image of the wafer 20 obtained is clearer, the minimum particle size that can be resolved can be smaller, the detection sensitivity of the wafer inspection device 10 is higher, and small-sized defects can be better detected. The initial light is irradiated onto the wafer 20, and the wafer 20 emits scattered light. The wide channel scattered light beam is received by the first detector 1130 through the first reflector 1110 and the first lens group 1120, and the narrow channel scattered light beam is received by the second detector 1230 through the second lens group 1120 and the second reflector 1210. With this arrangement, different adjustments can be made to different parts of the scattered light beam, and the adjustment is more targeted and has a better adjustment effect. The scattered light scattered by the wafer 20 is received by the first detector 1130 and the second detector 1230 respectively after adjustment, further ensuring the imaging effect and improving the detection capability of surface defects of the wafer 20. Exemplarily, the second reflector 1210 can be a plane reflector.

[0063] For example, in conjunction with reference Figure 1 and Figure 3 , the second lens group 1120 may include a third lens 1221, a fourth lens 1222, and a fifth lens 1223 located between the third lens 1221 and the fourth lens 1222. The third lens 1221 may be closer to the wafer 20 than the fourth lens 1222. The third lens 1221 may adjust the scattered light beam to be a second parallel light beam, the fourth lens 1222 may adjust the second parallel light beam to be a divergent light beam, and the fifth lens 1223 may adjust the divergent light beam to be a second adjustment light beam. Part of the scattered light beam passes through the third lens 1221, the fifth lens 1223, and the fourth lens 1222 in sequence, and is finally adjusted to be a second adjustment light beam and directed to the second reflector 1210. Among them, the third lens 1221 may collimate the scattered light beam to become a second parallel light beam, the fifth lens 1223 may diverge the second parallel light beam to become a divergent light beam, and the fourth lens 1222 may converge the divergent light beam to become a second adjustment light beam. In this way, under the premise of ensuring a better imaging effect, the structure of the second lens group 1120 is simpler and the light loss is less.

[0064] For example, refer to Figure 3 , the side of the third lens 1221 facing the wafer 20 can be a planar structure, and the side of the third lens 1221 facing the second reflector 1210 can be a convex structure. Exemplarily, the side of the fifth lens 1223 facing the wafer 20 is a planar structure, and the side of the fifth lens 1223 facing the second reflector 1210 is a concave structure. Exemplarily, the side of the fourth lens 1222 facing the wafer 20 and the side facing the second reflector 1210 are both convex structures. That is to say, the third lens 1221 can be a single convex mirror, the fifth lens 1223 can be a single concave mirror, and the fourth lens 1222 can be a double convex mirror. In this way, the structural setting is simpler, and the scattered light beam can be adjusted to the second adjustment light beam more efficiently.

[0065] For example, refer to Figure 3 , the third lens 1221 is a single convex lens and the side facing the second reflector 1210 is a spherical structure, and the radius of curvature can be 15.9mm~16.2mm. For example, the radius of curvature of the spherical structure of the third lens 1221 can be 15.9mm, 16.05mm or 16.2mm, etc. The third lens 1221 set in this way has a more moderate adjustment effect on the light beam, ensuring the imaging effect and better detection sensitivity. Exemplarily, the fifth lens 1223 can be a single concave lens and the side facing the second reflector 1210 is a concave spherical structure, and the radius of curvature is 67mm~71mm. For example, the radius of curvature of the concave spherical structure of the fifth lens 1223 is 67mm, 68.769mm, 71mm, etc. In this way, the divergence effect of the fifth lens 1223 on the second parallel light beam is more moderate to ensure the imaging effect and detection sensitivity. Exemplarily, the fourth lens 1222 may be a biconvex lens, and the side of the fourth lens 1222 facing the wafer 20 and the side facing the second reflector 1210 may both be spherical structures with the same radius of curvature, and the radius of curvature may be 67 mm to 71 mm. For example, the radius of curvature of the spherical structure of the fourth lens 1222 may be 67 mm, 68.545 mm, or 71 mm. The fourth lens 1222 configured in this way has a better convergence effect on the divergent light beam, ensuring the imaging effect.

[0066] For example, refer to Figure 3, the thickness of the third lens 1221 can be 4.8mm to 5.2mm. For example, the thickness of the third lens 1221 can be 4.8mm, 5mm or 5.2mm, etc. The third lens 1221 set in this way has a better adjustment effect on the scattered light beam to ensure the imaging effect and detection sensitivity. Among them, in the embodiment where the third lens 1221 is a single convex lens, the thickness of the third lens 1221 can be understood as the thickness of the thickest part of the third lens 1221. Exemplarily, the thickness of the fifth lens 1223 can be 2.4mm to 2.6mm. For example, the thickness of the fifth lens 1223 can be 2.4mm, 2.5mm or 2.6mm, etc. The fifth lens 1223 set in this way has a more moderate divergence effect on the second parallel light beam, and has better imaging effect and detection capability. In the embodiment where the fifth lens 1223 is a single concave lens, the thickness of the fifth lens 1223 can be understood as the thickness of the thinnest part of the fifth lens 1223. Exemplarily, the thickness of the fourth lens 1222 is 4.77 mm to 4.97 mm. For example, the thickness of the fourth lens 1222 may be 4.77 mm, 4.87 mm, or 4.97 mm, etc. In this way, the convergence effect of the fourth lens 1222 on the divergent light beam is more moderate, ensuring the imaging effect and detection sensitivity. In the embodiment where the fourth lens 1222 is a biconvex lens, the thickness of the fourth lens 1222 may be understood as the thickness of the thickest part of the fourth lens 1222.

[0067] For example, refer to Figure 3 , there may be a fifth distance D5 between the third lens 1221 and the wafer 20, and D5 may be 24mm to 26mm. For example, D5 may be 24mm, 25mm or 26mm, etc. The fifth distance may also be understood as the distance between the second lens group 1120 and the wafer 20. The focus of the third lens 1221 may overlap with a partial structure of the wafer 20. With this arrangement, the distance between the third lens 1221 and the wafer 20 is more moderate, the imaging is clearer, and the detection capability is better. Exemplarily, there is a sixth distance D6 between the fourth lens 1222 and the second reflector 1210, and D6 is 80mm to 82mm. For example, D6 may be 80mm, 81.03mm or 26mm, etc. The sixth distance may also be understood as the distance between the second lens group 1120 and the second reflector 1210. With this arrangement, the distance between the fourth lens 1222 and the second reflector 1210 is more moderate, and the imaging is clearer. Exemplarily, there may be a seventh distance D7 between the second reflector 1210 and the second detector 1230, and D7 may be 139 mm to 140 mm. For example, D7 may be 139 mm, 139.5 mm, or 140 mm, etc. In this way, the distance between the second reflector 1210 and the second detector 1230 is more moderate, and the second detector 1230 can better receive the second adjustment beam to ensure imaging effect and detection capability.

[0068] For example, refer to Figure 3 , there may be an eighth distance D8 between the third lens 1221 and the fifth lens 1223, and D8 is 7mm to 9mm. For example, the eighth distance may be 7mm, 8mm or 9mm, etc. In the embodiment where the third lens 1221 is a single convex lens and the fifth lens 1223 is a single concave lens, the eighth distance may be understood as the distance between the convex vertex of the third lens 1221 and the plane of the fifth lens 1223. With this arrangement, the divergence effect of the fifth lens 1223 on the second parallel light beam is more moderate, and the imaging effect is better. Exemplarily, there may be a ninth distance D9 between the fifth lens 1223 and the fourth lens 1222, and D9 may be 3.5mm to 4.5mm. For example, the ninth distance may be 3.5mm, 4mm or 4.5mm, etc. In the embodiment where the fifth lens 1223 is a single concave lens and the fourth lens 1222 is a double convex lens, the ninth distance may be understood as the distance between the concave vertex and the convex vertex. In this way, the fourth lens 1222 has a more moderate converging effect on the divergent light beam, thereby ensuring the imaging effect and detection sensitivity.

[0069] For example, refer to Figure 3 A second aperture 1240 may be provided between the second reflector 1210 and the second detector 1230. That is, the second aperture 1240 is provided on the optical path of the second reflected light beam. The second reflected light beam passes through the second aperture 1240 before being emitted to the second detector 1230. The provision of the second aperture 1240 can filter out the interfering light waves in the second reflected light beam, and has the effect of eliminating noise, that is, improving the ratio of the optical signal power to the noise power of the imaging of the second detector 1230, and further enabling the second detector 1230 to distinguish smaller particles, thereby improving the imaging resolution and the detection sensitivity.

[0070] For example, in conjunction with reference Figure 1 and Figure 3 , the angle between the scattered light beam adjusted by the second lens group 1120 and the normal of the wafer 20 is 0-10°. Compared with the partial scattered light beam reflected by the first reflector 1110, the angle between the partial scattered light beam and the normal of the wafer 20 is smaller, and the partial scattered light beam can be called a narrow channel scattered light beam. Correspondingly, the partial scattered light beam reflected by the first reflector 1110 can be called a wide channel scattered light beam. In this way, the second lens group 1120 adjusts the narrow channel scattered light beam so that the partial structure of the wafer 20 and the second detector 1230 establish object-image mapping.

[0071] For example, in conjunction with reference Figure 1 and Figure 3A second filter 1250 may be further disposed between the second reflector 1210 and the second detector 1230. For example, a second polarizer may be further disposed between the second reflector 1210 and the second detector 1230. For example, a second attenuation plate may be further disposed between the second reflector 1210 and the second detector 1230.

[0072] For example, in conjunction with reference Figure 1 and Figure 2 , the angle between the scattered light beam corresponding to the reflection of the first reflector 1110 and the normal of the wafer 20 is 15° to 83°. In this way, the first reflector 1110 group adjusts the wide channel scattered light beam so that the partial structure of the wafer 20 establishes object-image mapping with the first detector 1130. The wafer detection device 10 includes a 355nm laser, and for the collection angle of 83° of the wide channel scattered light beam, the object space numerical aperture NA on the side of the wafer 20 can be 0.9928. The distance between the wafer 20 and the first reflector 1110 is 10.5mm. Therefore, the object space F number is 1.195, and the image space numerical aperture NA on the end of the first detector 1130 is 0.2.

[0073] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by directional words such as "front", "back", "up", "down", "left", "right", "lateral", "vertical", "vertical", "horizontal", "top", "bottom", etc. is usually based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the scope of protection of the present invention; the directional words "inside" and "outside" refer to the inside and outside relative to the contour of each component itself.

[0074] For ease of description, regional relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the regional positional relationship between one or more components or features shown in the figure and other components or features. It should be understood that regional relative terms include not only the orientation of the components as described in the figure, but also different orientations in use or operation. For example, if the components in the accompanying drawings are inverted as a whole, the components "above other components or features" or "above other components or features" will include the situation where the components are "below other components or structures" or "below other components or structures". Therefore, the exemplary term "above" may include both "above" and "below". In addition, these components or features may also be positioned at other different angles (e.g., rotated 90 degrees or other angles), and this article is intended to include all of these situations.

[0075] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, parts, components and / or combinations thereof.

[0076] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein.

[0077] The present invention has been described by the above embodiments, but it should be understood that the above embodiments are only for the purpose of example and description, and are not intended to limit the present invention to the scope of the described embodiments. In addition, it can be understood by those skilled in the art that the present invention is not limited to the above embodiments, and more variations and modifications can be made according to the teachings of the present invention, and these variations and modifications all fall within the scope of the protection claimed by the present invention. The protection scope of the present invention is defined by the attached claims and their equivalents.

Claims

1. A wafer inspection device, characterized in that: include: A light source (110), the light source (110) emitting initial light to the wafer (20) so that the wafer (20) emits a scattered light beam; a first reflector (1110), the first reflector (1110) being located on a side of the wafer (20) facing the light source (110) and reflecting at least a portion of the scattered light beam into a first reflected light beam; a first lens group (1120), the first lens group (1120) being located on a side of the first reflector (1110) away from the wafer (20) and adjusting the first reflected light beam to a first adjusted light beam, wherein a divergence angle of the first adjusted light beam is smaller than a divergence angle of the first reflected light beam; and A first detector (1130), wherein the first detector (1130) is disposed on a side of the first lens group (1120) away from the wafer (20) and receives the first adjustment light beam.

2. The wafer inspection device according to claim 1, characterized in that: A first aperture (1140) is arranged between the first lens group (1120) and the first reflector (1110).

3. The wafer inspection device according to claim 2, characterized in that: There is a first distance D1 between the first aperture (1140) and the first lens group (1120), and D1 is 2.5 mm to 3.5 mm.

4. The wafer inspection device according to claim 2, characterized in that: There is a second distance D2 between the first aperture (1140) and the first reflector (1110), and D2 is 240 mm to 248 mm.

5. The wafer inspection device according to claim 1, characterized in that: The first lens group (1120) includes a first lens (1121) and a second lens (1122), wherein the first lens (1121) is closer to the first reflector (1110) than the second lens (1122), the first lens (1121) adjusts the first reflected light beam into a first parallel light beam, and the second lens (1122) adjusts the first parallel light beam into the first adjusted light beam.

6. The wafer inspection device according to claim 5, characterized in that: The side of the first lens (1121) facing the first reflector (1110) is a planar structure, and the side facing away from the first reflector (1110) is a convex structure; and / or The side of the second lens (1122) facing the first reflector (1110) is a convex structure, and the side away from the first reflector (1110) is a planar structure.

7. The wafer inspection device according to claim 5, characterized in that: The central thickness of the first lens (1121) is 11 mm to 13 mm; and / or The central thickness of the second lens (1122) is 7.0 mm to 7.4 mm.

8. The wafer inspection device according to claim 5, characterized in that: There is a third distance D3 between the first lens (1121) and the second lens (1122), and D3 is 13 mm to 17 mm; and / or There is a fourth distance D4 between the second lens (1122) and the first detector (1130), and D4 is 4.5 mm to 4.7 mm.

9. The wafer inspection device according to claim 1, characterized in that: The first reflector (1110) comprises an ellipsoid reflector, the projection of the ellipsoid reflector in the plane where the wafer (20) is located surrounds the wafer (20).

10. The wafer inspection device according to claim 9, characterized in that: The ellipsoidal reflector forms a first focus and a second focus, at least a portion of the structure of the wafer (20) coincides with the first focus, and the first lens group (1120) is located between the second focus and the first detector (1130).

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