Wafer detection system

Abstract

A wafer inspection system includes a wafer inspection tool. An illumination source is in the wafer inspection tool and is used to generate a radiation beam. The first optical element and the second optical element are in the wafer inspection tool and are optically coupled with the illumination source. The first beam inspection tool is between the first optical element and the second optical element, where the first beam inspection tool includes a first aperture, and the first optical element and the second optical element are optically coupled via the first aperture of the first beam inspection tool.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a wafer inspection system. BACKGROUND

[0002] Fabricating semiconductor devices such as logic and memory devices typically includes processing a substrate such as a semiconductor wafer using a large number of semiconductor

[0003] Inspection processes are used at various steps in the semiconductor manufacturing process to detect defects on wafers or reticles to promote higher yield in the manufacturing process and thus higher profits. However, as the dimensions of semiconductor devices decrease, detection becomes increasingly important to successfully manufacture acceptable semiconductor devices as smaller defects can cause device failure. For example, as the dimensions of semiconductor devices decrease, it becomes necessary to detect smaller defects because even relatively small defects can cause unwanted aberrations in the semiconductor devices. In addition, as design rules shrink, the semiconductor manufacturing process can be closer to the limits of the process capability and smaller defects can have an impact on the electrical parameters of the devices. SUMMARY

[0004] In some embodiments of the present disclosure, a wafer inspection system includes a wafer inspection tool. An illumination source is in the wafer inspection tool and is configured to generate a beam of radiation. A first optical element and a second optical element are in the wafer inspection tool and optically coupled with the illumination source. A first beam inspection tool is between the first optical element and the second optical element, wherein the first beam inspection tool includes a first aperture, and the first optical element and the second optical element are optically coupled via the first aperture of the first beam inspection tool.

[0005] In some embodiments of the present disclosure, a wafer inspection system includes a wafer inspection tool. An illumination source is in the wafer inspection tool and is configured to generate a beam of radiation. A first optical element and a second optical element are in the wafer inspection tool and optically coupled with the illumination source. A first beam inspection tool is between the first optical element and the second optical element, wherein the first beam inspection tool includes a first aperture, and the first optical element and the second optical element are optically coupled via the first aperture of the first beam inspection tool.

[0006] In some embodiments of the present disclosure, a wafer inspection system includes a wafer inspection tool. An illumination source is in the wafer inspection tool and is configured to generate a radiation beam. A first optical element and a second optical element are in the wafer inspection tool and optically coupled with the illumination source. A first beam inspection tool is between the first optical element and the second optical element, wherein the first beam inspection tool includes a first aperture, and the first optical element and the second optical element are optically coupled via the first aperture of the first beam inspection tool, wherein the first beam inspection tool includes an upwardly facing planar surface, and the first aperture is at the planar surface of the first beam inspection tool. BRIEF DESCRIPTION OF DRAWINGS

[0007] Aspects of the present disclosure are illustrated by way of example, and not by way of limitation, in the accompanying drawings, based on the accompanying drawings: Figure One Best understood when read in light of the following detailed description. It should be noted that the various features are not drawn to scale. In fact, the dimensions of the various features can be arbitrarily increased or decreased for the sake of discussion clarity.

[0008] Figure 1 is a schematic diagram of a wafer inspection optical system according to some embodiments of the present disclosure;

[0009] Figure 2 is a schematic diagram of a wafer inspection system according to some embodiments of the present disclosure;

[0010] Figures 3A-3D is a schematic diagram of an auxiliary tool according to some embodiments of the present disclosure;

[0011] Figures 4A-4B illustrates a relationship between an auxiliary tool and a fixation plate according to some embodiments of the present disclosure;

[0012] Figures 5A-5B illustrates different cases of determining a propagation path of a radiation beam according to some embodiments of the present disclosure;

[0013] Figures 6A-6D is a schematic diagram of an auxiliary tool according to some embodiments of the present disclosure;

[0014] Figures 7A-7B illustrates a relationship between an auxiliary tool and a fixation plate according to some embodiments of the present disclosure;

[0015] Figures 8A-8B illustrates different cases of determining a propagation path of a radiation beam according to some embodiments of the present disclosure;

[0016] Figure 9 is a method of replacing an illumination source of a wafer inspection system according to some embodiments;

[0017] Figure 10A and Figure 10BFig. 1 illustrates the relationship between an assist tool and a reticle according to some embodiments of the present disclosure;

[0018] Figure 11 Fig. 1 is a block diagram of a wafer inspection system according to some embodiments of the present disclosure.

[0019]

Symbol Explanation

[0020] 10: wafer inspection optical system

[0021] 20: wafer inspection system

[0022] 30-40: assist tool / beam inspection tool

[0023] 100: illumination source

[0024] 102: polarizing cube

[0025] 104: half-wave plate

[0026] 106: quarter-wave plate

[0027] 108: first lens

[0028] 110: spatial filter

[0029] 112: second lens

[0030] 114: first cylindrical lens

[0031] 116: second cylindrical lens

[0032] 118: third cylindrical lens

[0033] 120: Fresnel lens

[0034] 122: P-polarizer

[0035] 124: S-polarizer

[0036] 126: parabolic collector

[0037] 128: collector attenuator

[0038] 130: photomultiplier tube (PMT)

[0039] 140: reflected detector

[0040] 142: reflected attenuator

[0041] 150: under-wafer detector

[0042] 152: under-wafer parabolic mirror

[0043] 200: wafer inspection tool

[0044] 202: input device

[0045] 204: output device

[0046] 210: wafer load port

[0047] 220, 222: fixed plate

[0048] 230, 232: image capturing device

[0049] 240: computer system

[0050] 300: fixed portion

[0051] 310: main portion

[0052] 310A: first section of 310

[0053] 310B: second section of 310

[0054] 400: fixed portion

[0055] 410: main portion

[0056] 410A: first section of 410

[0057] 410B: second section of 410

[0058] 1000: method

[0059] C1: center of H1

[0060] C2: center of LS1

[0061] C3: center of H2

[0062] C4: center of LS2

[0063] D1: diameter

[0064] DS11, DS12: distance

[0065] FH1, FH2: fixed hole

[0066] H1, H2: hole

[0067] L1: first line

[0068] L2: second line

[0069] L3: first line

[0070] L4: second line

[0071] LH11, LH12, LH13, LH14, LH15: length

[0072] LH21, LH22, LH23, LH24, LH25, LH26, LH27: length

[0073] LS1, LS2: light spot

[0074] M1: turning mirror

[0075] M2: scanning mirror

[0076] M3: telecentric scanning mirror

[0077] M4: entrance mirror

[0078] R1, R2, R3, R4: radiation beam

[0079] RM1, RM2: reflecting mirror

[0080] S11, S12, S13, S14: shortest distance

[0081] S21, S22, S23, S24: shortest distance

[0082] S101, S102, S103, S104, S105, S106: operation

[0083] TH11, TH12, TH13: thickness

[0084] TH21, TH22, TH23: thickness DETAILED DESCRIPTION

[0085] The following disclosure provides many different embodiments, or examples, for implementing different characteristics of the provided subject matter. Specific examples of components and configurations are described below to simplify the present disclosure. These are, of course, merely examples and are not intended to be limiting. For example, in the following description, the formation of a first feature on, on top of, or over a second feature can include embodiments in which the first feature is formed directly on the second feature, and can also include embodiments in which additional features can be formed between the first and second features such that the first and second features can not be directly in contact. In addition, the present disclosure can make repeated reference to a reference number and / or letter in various examples. This repetition is for the purpose of simplicity and clarity and does not itself imply a relationship between the various embodiments and / or configurations discussed.

[0086] Further, to facilitate description, spatially relative terms, such as "beneath", "below", "lower", "above", "upper", and the like, can be used herein for the purpose of describing elemental relationship between one element or feature and another element or feature as illustrated in the figures. Spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientations depicted in the figures. The device can be otherwise oriented (rotated 90 degrees, or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. As used herein, "about", "approximately", "near", or "substantially" can generally mean within 20 percent, or within 10 percent, or within 5 percent of a given value or range. Numerical values given herein are approximate, meaning that the term "about", "approximately", "near", or "substantially" can be inferred if not expressly stated. However, those of ordinary skill in the art will recognize that the values or ranges referred to throughout the specification are merely examples, and can decrease or change as integrated circuits scale in size.

[0087] Figure 1 FIG. 1 is a schematic diagram of a wafer inspection optical system according to some embodiments of the present disclosure. A wafer inspection optical system 10 is shown. In some embodiments, the wafer inspection optical system 10 is used to detect and classify defects on a semiconductor wafer, enabling manufacturers to identify and correct potential problems early in the production process. In some embodiments, the wafer inspection optical system 10 can be capable of capturing high-resolution images of the wafer surface to detect defects on the wafer surface. In some embodiments, the wafer inspection optical system 10 can also be capable of automatically classifying the type of defect based on the size, shape, and location of the defect. The wafer inspection optical system 10 is used to generate early defect detection, which leads to higher yields and improved overall quality control. In addition, the wafer inspection optical system 10 provides real-time monitoring of wafer quality, which minimizes the risk of yield loss caused by process variations. Last but not least, early capture of defects can also reduce production costs and improve profitability. In some embodiments, the wafer inspection optical system 10 can be used in memory device fabrication, logic device fabrication, and advanced packaging within the semiconductor industry. It should be understood, Figure 1 The optical elements shown in FIG. 1 are for explanation only, and the present disclosure is not limited thereto. Some optical elements can be omitted, and the wafer inspection optical system 10 can also include other optical elements not present in FIG. 1. Figure 1

[0088] ​Wafer inspection optical system 10 includes an illumination source 100. In some embodiments, illumination source 100 can produce a radiation beam Rl toward a turning mirror Ml. In the present embodiment, illumination source 100 can be a 30 MW argon (Ar) laser source, but the present disclosure is not limited thereto. In other embodiments, illumination source 100 can also include, for example, a laser, a diode laser, a helium-neon laser, a solid-state laser, a diode pumped solid state (DPSS) laser, a xenon arc lamp, a gas discharge lamp, and an LED array, an incandescent lamp, or other suitable laser source.

[0089] Along the propagation path of radiation beam Rl between illumination source 100 and turning mirror Ml, radiation beam Rl can pass through several optical elements, such as a polarizing cube 102, a half-wave plate 104, a quarter-wave plate 106, a first lens 108, a spatial filter 110, and a second lens 112.

[0090] In some embodiments, polarizing cube 102 can be a polarizing beam splitter cube, a Wollaston prism, or some other suitable polarizing beam splitter. For example, polarizing cube 102 can be constructed from two cemented right-angle prisms. In some embodiments, polarizing cube 102 is used to allow passage of portions of radiation having the appropriate polarization.

[0091] Radiation passing through polarizing cube 102 propagates to half-wave plate 104. In some embodiments, half-wave plate 104 allows dynamic rotation of polarization between P-polarization (parallel to the plane of incidence), S-polarization (perpendicular to the plane of incidence), and 45° polarization (between P and S).

[0092] Radiation passing through half-wave plate 104 propagates to quarter-wave plate 106. Quarter-wave plate 106 produces a quarter- wavelength phase delay compared to half-wave plate 104. If quarter-wave plate 106 is oriented at 45° with respect to a linearly polarized beam, the output beam will be circularly polarized light, and vice versa. In some embodiments, half-wave plate 104 and quarter-wave plate 106 can be collectively referred to as beam shaping optical elements. Beam shaping optical elements (e.g., half-wave plate 104 and quarter-wave plate 106) can be used to reshape an incident beam to a circular cross-section.

[0093] Radiation passing through quarter-wave plate 106 propagates to first lens 108. In some embodiments, first lens 108 can be a focusing lens used to direct radiation onto spatial filter 110. In some embodiments, first lens 108 can be a spherical lens.

[0094] The radiation that passes through the first lens 108 propagates to a spatial filter 110. In some embodiments, the spatial filter 110 is used to remove unwanted orders of energy peaks and pass only the central maximum of the diffraction pattern of the radiation. In addition, when the radiation passes through the optical path, dust in the air or on the optical components can destroy the beam and create scattered light. This scattered light can leave unwanted annular patterns in the beam profile. The spatial filter 110 can also remove this extra spatial noise from the system.

[0095] The radiation that passes through the spatial filter 110 propagates to a second lens 112. In some embodiments, the second lens 112 can be a focusing lens that is used to direct the radiation onto a turning mirror Ml. In some embodiments, the second lens 112 can be a spherical lens.

[0096] The turning mirror Ml can reflect the radiation beam Rl and redirect the radiation beam Rl toward a scanning mirror M2. In some embodiments, the radiation beam Rl reflected by the turning mirror Ml is referred to as the radiation beam R2. In some embodiments, the scanning mirror M2 can also be referred to as a scanner. The mirror in the scanner (e.g., the scanning mirror M2) can oscillate its angle with respect to the radiation beam passing through the scanner.

[0097] The scanning mirror M2 can reflect the radiation beam R2 and redirect the radiation beam R2 to a telecentric scanning mirror M3. In some embodiments, the radiation beam R2 reflected by the telecentric scanning mirror M3 is referred to as the radiation beam R3.

[0098] The telecentric scanning mirror M3 can reflect the radiation beam R3 and redirect the radiation beam R3 to an entrance mirror M4. In some embodiments, the radiation beam R3 reflected by the telecentric scanning mirror M3 is referred to as the radiation beam R4. Along the propagation path of the radiation beam R4 between the telecentric scanning mirror M3 and the entrance mirror M4, the radiation beam R4 can pass through a first cylindrical lens 114, a second cylindrical lens 116, and a third cylindrical lens 118. In some embodiments, a cylindrical lens is a lens that focuses light into a line (rather than a point as with a spherical lens). One or more curved surfaces of a cylindrical lens are part of a cylinder that focuses an image passing through it into a line that is parallel to the intersection of the lens surface and the plane tangent to the axis of the cylinder.

[0099] The entrance mirror M4 can reflect the radiation beam R4 and redirect the radiation beam R4 onto the surface of the wafer W. When the radiation beam R4 illuminates a defect on the surface of the wafer W, radiation light scatters away from the point of incidence. In some embodiments, the scattered light can pass through a Fresnel lens 120, a P-polarizer 122, an S-polarizer 124, a parabolic collector 126, a collector attenuator 128, and a photomultiplier tube (PMT) 130.

[0100] In some embodiments, the Fresnel lens 120 is used to focus the scattered light from the wafer W. The P-polarizer 122 and the S-polarizer 124 are used to produce the desired polarization state of the scattered light. The parabolic collector 126 is used to direct the scattered light to the photomultiplier tube (PMT) 130. The collector attenuator 128 is used to control the radiant power into the photomultiplier tube (PMT) 130. In some embodiments, the photomultiplier tube 130 is used to amplify the light signal and produce a corresponding electrical output. The output of the photomultiplier tube 130 is digitized by an analog-to-digital converter (not shown). Then, the particle locations (e.g., defect locations) on the wafer W can be determined based on the collected radiation.

[0101] On the other hand, in addition to the scattered light from the wafer surface, the radiation beam R4 can also be reflected by the wafer W. The reflected light can be directed to the mirror RM1, which directs the light to the mirror RM2, which directs the light to the reflection detector 140 via the reflection attenuator 142. In some embodiments, the reflection attenuator 142 is used to control the radiant power into the reflection detector 140. In some embodiments, the reflection detector is used to amplify the light signal and produce a corresponding electrical output. The output of the reflection detector 140 is digitized by an analog-to-digital converter (not shown). Then, the reflected light from the wafer W can be determined based on the collected radiation.

[0102] On the other hand, the wafer inspection optical system 10 further includes a sub-wafer detector 150. When the wafer W is not present, the radiation beam R4 can be directed to the sub-wafer detector 150 via the sub-wafer parabolic mirror 152. In some embodiments, the sub-wafer detector 150 can be used to detect the radiant intensity of the radiation beam R4.

[0103] Figure 2 is a schematic diagram of a wafer inspection system according to some embodiments of the present disclosure. The wafer inspection system 20 is shown. In some embodiments, the wafer inspection system 20 includes a wafer inspection tool 200. In some embodiments, as shown in Figure 1 the wafer inspection optical system 10 is integrated in Figure 2 the wafer inspection tool 200. The wafer inspection tool 200 includes a wafer load port 210. For example, when a wafer (such as the wafer W shown in Figure 1 is placed in the wafer load port 210, the wafer W will be transferred to the inspection position of the wafer inspection optical system 10 as shown in Figure 1

[0104] In some embodiments, the wafer inspection tool 200 also includes an input device 202 and an output device 204. The input device 202 is used to input data to the computer system (e.g.,​Figure 11 The computer system 240 generates wafer detection instructions. The computer system can transmit the instructions to a wafer detection optical system 10 (see Figure 1 ) integrated in the wafer detection tool 200. The detection results of the wafer detection optical system 10 are sent back to the computer system, and the detection results can be displayed on the output device 204. In some embodiments, the input device 202 can include a keyboard, a mouse, or other suitable input device. In some embodiments, the output device 204 can include a monitor, or other suitable output device.

[0105] During the operation of the wafer detection system 20, it is observed that the average lifetime of the illumination source (e.g., the illumination source 100 in Figure 1 ) is about 10 months to 12 months, and the used illumination source will be replaced with a new illumination source. For example, the illumination source (e.g., the illumination source 100 in Figure 1 ) is removed from the wafer detection tool 200 of the wafer detection system 20, and a new illumination source is installed into the wafer detection tool 200 of the wafer detection system 20. However, once the new illumination source is installed, the radiation beams can not propagate along the predetermined propagation paths. That is, the propagation paths of the radiation beams (e.g., the radiation beams R1, R2, R3, and / or R4 in Figure 1 ) can deviate from the predetermined propagation paths, and such deviated propagation paths can adversely affect the detection accuracy.

[0106] Figures 3A-3D are various views of an auxiliary tool according to some embodiments of the present disclosure. More specifically, Figure 3A is a schematic view of the auxiliary tool 30, Figure 3B is a top view of the auxiliary tool 30, Figure 3C is a side view of the auxiliary tool 30, and Figure 3D is a cross-sectional view of the auxiliary tool 30. In some embodiments, the auxiliary tool 30 is used to inspect the propagation paths of the radiation beams, and thus the auxiliary tool 30 can also be referred to as a beam inspection tool.

[0107] The auxiliary tool 30 includes a fixed portion 300 and a main body portion 310 connected to each other. More specifically, the main body portion 310 further includes a first segment 310A and a second segment 310B connected to each other. In some embodiments, the fixed portion 300 is in contact with the second segment 310B of the main body portion 310. That is, the second segment 310B of the main body portion 310 is between the fixed portion 300 and the first segment 310A of the main body portion 310.

[0108] In some embodiments, both the fixing portion 300 and the second segment 310B of the main body portion 310 are cylindrical, while the first segment 310A of the main body portion 310 is semi-cylindrical. That is, both the fixing portion 300 and the second segment 310B of the main body portion 310 are circular cross-sectional profiles, while the first segment 310A of the main body portion 310 is substantially semi-circular cross-sectional profile. In some embodiments, the first segment 310A of the main body portion 310 includes a curved surface connected to a flat surface. In some embodiments, the diameter of the circular cross-sectional profile of the fixing portion 300 is smaller than the diameter of the circular cross-sectional profile of the second segment 310B of the main body portion 310.

[0109] In some embodiments, the body portion 310 may include a hole H1 passing through a first segment 310A of the body portion 310. Specifically, the hole H1 may extend from a flat surface of the first segment 310A of the body portion 310 to a curved surface of the first segment 310A of the body portion 310. In other words, a first end of the hole H1 may be located at the flat surface of the first segment 310A of the body portion 310, and a second end of the hole H1 may be located at the curved surface of the first segment 310A of the body portion 310. In some embodiments, the hole H1 may include a circular outline.

[0110] like Figure 3C As shown, along the longitudinal direction of the auxiliary tool 30, the auxiliary tool 30 includes a length LH11, the fixing portion 300 of the auxiliary tool 30 includes a length LH12, and the main body portion of the auxiliary tool 30 includes a length LH13, wherein the length LH11 is the sum of the lengths LH12 and LH13. In some embodiments, the length LH11 is about 47.5 mm to about 48.5 mm, such as 48 mm. The length LH12 is about 9.0 mm to about 10.0 mm, such as 9.5 mm. The length LH13 is about 38.0 mm to about 39.0 mm, such as 38.5 mm.

[0111] like Figure 3DAs shown, the first section 310A of the body portion 310 of the auxiliary tool 30 includes a length LH14, and the second section 310B of the body portion 310 of the auxiliary tool 30 includes a length LH15, where the length LH13 is the sum of the length LH14 and the length LH15. In some embodiments, the length LH14 is about 28.0 mm to about 29.0 mm, such as 28.5 mm. In some embodiments, the length LH15 is about 9.5 mm to about 10.5 mm, such as 10 mm. The hole H1 includes a diameter D1. In some embodiments, the diameter D1 is about 11.5 mm to about 12.5 mm, such as 12 mm. There is a distance DS11 between the center of the hole H1 and the outer sidewall of the first section 310A of the body portion 310 of the auxiliary tool 30. In some embodiments, the distance DS11 is about 18.5 mm to about 19.5 mm, such as 19 mm. The fixing portion 300 of the auxiliary tool 30 includes a thickness TH11 (or diameter). In some embodiments, the thickness TH11 is about 4.2 mm to about 5.2 mm, such as 4.7 mm. The first section 310A of the body portion 310 of the auxiliary tool 30 includes a thickness TH12, and the second section 310B of the body portion 310 of the auxiliary tool 30 includes a thickness TH13 (or diameter). In some embodiments, the thickness TH12 is about 7.6 mm to about 8.6 mm, such as 8.1 mm. In some embodiments, the thickness TH13 is about 15.3 mm to about 16.3 mm, such as 15.8 mm.

[0112] Figures 4A-4B The relationship between the auxiliary tool and the fixing plate according to some embodiments of the present disclosure is illustrated. The wafer inspection system 20 can include a fixing plate 220 and a fixing plate 222, where the fixing plate 220 and the fixing plate 222 include a fixing hole FH1 and a fixing hole FH2, respectively. Here, the auxiliary tool 30 and the fixing plate 220 will be used to determine the propagation path of the radiation beam R2 (see Figure 1 ). The fixing plate 222 will be used to determine the propagation path of another radiation beam R4 (see Figure 1 ), which will be discussed in more detail later.

[0113] In determining the propagation path of the radiation beam R2 (see Figure 1 ), the auxiliary tool 30 is fixed on the fixing plate 220. Specifically, the fixing portion 300 of the auxiliary tool 30 is inserted into the fixing hole FH1 of the fixing plate 220. In some embodiments, the auxiliary tool 30 and the fixing plate 220 can be designed such that the dimensions of the fixing portion 300 of the auxiliary tool 30 can match the dimensions of the fixing hole FH1 of the fixing plate 220. Therefore, the auxiliary tool 30 can be stably fixed on the fixing plate 220.

[0114] The position and dimension of the auxiliary tool 30 and the fixing plate 220 can be designed such that the auxiliary tool 30 is between the optical path between the turning mirror Ml and the scanning mirror M2 of the wafer inspection optical system 10. Specifically, the turning mirror Ml can direct the radiation beam R2 toward the scanning mirror M2, and the radiation beam R2 can pass through the hole Hl of the auxiliary tool 30. In some embodiments, the shape of the hole Hl of the auxiliary tool 30 can be designed to have substantially the same cross-sectional profile as the radiation beam R2. For example, it is observed that the radiation beam R2 includes a circular profile, and thus the hole Hl of the auxiliary tool 30 can be designed to have a circular profile.

[0115] The first end of the hole Hl at the flat surface of the auxiliary tool 30 can face upward toward the turning mirror Ml, and the second end of the hole Hl at the flat surface of the auxiliary tool 30 can face downward toward the scanning mirror M2. Once the radiation beam R2 propagates toward the auxiliary tool 30, a portion of the radiation beam R2 can pass through the hole Hl of the auxiliary tool 30, and another portion of the radiation beam R2 can be incident on the flat surface of the auxiliary tool 30 and generate a light spot LSI on the flat surface of the auxiliary tool 30. Based on the relationship between the light spot LSI and the hole Hl of the auxiliary tool 30, the propagation path of the radiation beam R2 can be determined, which will be discussed in more detail later.

[0116] Figures 5A-5B Different cases of determining the propagation path of the radiation beam are illustrated according to some embodiments of the present disclosure. In more detail, Figure 5A for a case that the propagation path of the radiation beam R2 is along the predetermined propagation path, Figure 5B for a case that the propagation path of the radiation beam R2 deviates from the predetermined propagation path.

[0117] A first example of determining the propagation path of the radiation beam R2 includes comparing the position of the center Cl of the hole Hl with the position of the center C2 of the light spot LSI. If the center Cl of the hole Hl overlaps with the center C2 of the light spot LSI, the propagation path of the radiation beam R2 is determined to be along the predetermined propagation path. For example, in Figure 5A , the center Cl of the hole Hl overlaps with the center C2 of the light spot LSI. However, if the center Cl of the hole Hl does not overlap with the center C2 of the light spot LSI, the propagation path of the radiation beam R2 is determined to deviate from the predetermined propagation path. For example, in Figure 5B , the center Cl of the hole Hl does not overlap with the center C2 of the light spot LSI.

[0118] A second instance of determining the propagation path of the radiation beam R2 includes comparing the distances between the boundary of the hole H1 and the boundary of the light spot LS1. For example, in a first line L1 along the length direction of the auxiliary tool 30 and passing through the center C1 of the hole H1, the first end of the boundary of the hole H1 and the boundary of the light spot LS1 include a shortest distance S11, and the second end of the boundary of the hole H1 and the boundary of the light spot LS1 include a shortest distance S12, where the first end is opposite to the second end. On the other hand, in a second line L2 perpendicular to the length direction of the auxiliary tool 30 and passing through the center C1 of the hole H1, the first end of the boundary of the hole H1 and the boundary of the light spot LS1 include a shortest distance S13, and the second end of the boundary of the hole H1 and the boundary of the light spot LS1 include a shortest distance S14.

[0119] If the distance S11 is substantially the same as the distance S12, and the distance S13 is substantially the same as the distance S14, the propagation path of the radiation beam R2 is determined to be along the predetermined propagation path. For example, in the case of Figure 5A , the distance S11 is substantially the same as the distance S12, and the distance S13 is substantially the same as the distance S14. However, if the distance S11 is different from the distance S12 and / or the distance S13 is different from the distance S14, the propagation path of the radiation beam R2 is determined to be deviated from the predetermined propagation path. For example, in the case of Figure 5B , the distance S11 is different from the distance S12, and the distance S13 is different from the distance S14.

[0120] Figures 6A-6D are various views of an auxiliary tool according to some embodiments of the present disclosure. In more detail, Figure 6A is a schematic view of an auxiliary tool 40, Figure 6B is a top view of the auxiliary tool 40, Figure 6C is a side view of the auxiliary tool 40, Figure 6D is a cross-sectional view of the auxiliary tool 40. In some embodiments, the auxiliary tool 40 is used to inspect the propagation path of a radiation beam, and thus the auxiliary tool 40 can also be referred to as a beam inspection tool.

[0121] The auxiliary tool 40 includes a fixed portion 400 and a main portion 410 connected to each other. In more detail, the main portion 410 further includes a first segment 410A and a second segment 410B connected to each other. In some embodiments, the fixed portion 400 is in contact with the second segment 410B of the main portion 410. That is, the second segment 410B of the main portion 410 is between the fixed portion 400 and the first segment 410A of the main portion 410.

[0122] In some embodiments, both the fixing portion 400 and the second segment 410B of the main body portion 410 are cylindrical, while the first segment 410A of the main body portion 410 is semi-cylindrical. That is, both the fixing portion 400 and the second segment 410B of the main body portion 410 are circular cross-sectional profiles, while the first segment 410A of the main body portion 410 is substantially semi-circular cross-sectional profile. In some embodiments, the first segment 410A of the main body portion 410 includes a curved surface connected to a flat surface. In some embodiments, the diameter of the circular cross-sectional profile of the fixing portion 400 is smaller than the diameter of the circular cross-sectional profile of the second segment 410B of the main body portion 410.

[0123] In some embodiments, the body portion 410 may include a hole H2 passing through a first segment 410A of the body portion 410. Specifically, the hole H2 may extend from a curved surface of the first segment 410A of the body portion 410 to a curved surface of the first segment 410A of the body portion 410. In other words, a first end of the hole H2 may be located on a flat surface of the first segment 410A of the body portion 410, and a second end of the hole H2 may be located on a curved surface of the first segment 410A of the body portion 410. In some embodiments, the hole H2 may include a strip profile with rounded opposite ends. Specifically, the shape of the hole H2 may include two lining portions connecting two curved portions.

[0124] like Figure 6C As shown, along the longitudinal direction of the auxiliary tool 40, the auxiliary tool 40 includes a length LH21, a fixing portion 400 of the auxiliary tool 40 includes a length LH22, and a body portion of the auxiliary tool 40 includes a length LH23, wherein the length LH21 is the sum of the lengths LH22 and LH23. In some embodiments, the length LH21 is about 59.8 mm to about 60.8 mm, such as 60.3 mm. The length LH22 is about 9.0 mm to about 10.0 mm, such as 9.5 mm. The length LH23 is about 50.3 mm to about 51.3 mm, such as 50.8 mm. The hole H2 may include a linear sidewall, the linear sidewall including a length LH27. In some embodiments, the length LH27 is about 9.45 mm to about 10.45 mm, such as 9.95 mm.

[0125] like Figure 3DAs shown, the first section 410A of the body portion 410 of the auxiliary tool 40 includes a length LH24, and the second section 410B of the body portion 410 of the auxiliary tool 40 includes a length LH25, where the length LH23 is the sum of the length LH24 and the length LH25. In some embodiments, the length LH24 is about 37.6.0 mm to about 38.6 mm, such as 38.1 mm. In some embodiments, the length LH25 is about 12.2 mm to about 13.2 mm, such as 12.7 mm. The hole H2 includes a length LH26. In some embodiments, the length LH26 is about 14.45 mm to about 15.45 mm, such as 14.95 mm.

[0126] The edge of the hole H2 and the outer sidewall of the first section 410A of the body portion 410 of the auxiliary tool 40 have a distance DS12. In some embodiments, the distance DS12 is about 11.0 mm to about 12.0 mm, such as 11.5 mm. The fixing portion 400 of the auxiliary tool 40 includes a thickness TH21 (or diameter). In some embodiments, the thickness TH21 is about 4.2 mm to about 5.2 mm, such as 4.7 mm. The first section 410A of the body portion 410 of the auxiliary tool 40 includes a thickness TH22, and the second section 410B of the body portion 410 of the auxiliary tool 40 includes a thickness TH23 (or diameter). In some embodiments, the thickness TH22 is about 7.6 mm to about 8.6 mm, such as 8.1 mm. In some embodiments, the thickness TH23 is about 15.3 mm to about 16.3 mm, such as 15.8 mm.

[0127] Figures 7A-7B The relationship between the auxiliary tool and the fixing plate according to some embodiments of the present disclosure is illustrated. Here, the auxiliary tool 40 and the fixing plate 222 will be used to determine the propagation path of the radiation beam R4 (see Figure 1 ).

[0128] In determining the propagation path of the radiation beam R4 (see Figure 1 ), the auxiliary tool 40 is fixed on the fixing plate 222. Specifically, the fixing portion 400 of the auxiliary tool 40 is inserted into the fixing hole FH2 of the fixing plate 222. In some embodiments, the auxiliary tool 40 and the fixing plate 222 can be designed such that the dimension of the fixing portion 400 of the auxiliary tool 40 can match the dimension of the fixing hole FH2 of the fixing plate 222. Therefore, the auxiliary tool 40 can be stably fixed on the fixing plate 222. In some embodiments, the fixing hole FH2 of the fixing plate 222 is lower than the fixing hole FH1 of the fixing plate 220, so the auxiliary tool 40 is positioned at a level lower than the auxiliary tool 30 (see Figure 4A ).

[0129] The position and dimension of the auxiliary tool 40 and the fixing plate 222 can be designed such that the auxiliary tool 40 is between the optical path between the telecentric scan mirror M3 and the entrance mirror M4 of the wafer inspection optical system 10. Specifically, the telecentric scan mirror M3 can direct the radiation beam R4 toward the entrance mirror M4, and the radiation beam R4 can pass through the hole H2 of the auxiliary tool 40. In some embodiments, the shape of the hole H2 of the auxiliary tool 40 can be designed to have a similar or substantially identical cross-sectional profile as the radiation beam R4. In some embodiments, the hole H2 and the radiation beam R4 can include a bar-shaped profile with rounded opposite ends. In other embodiments, the radiation beam R4 can include an elliptical profile.

[0130] The first end of the hole H2 at the flat surface of the auxiliary tool 40 can face upward toward the telecentric scan mirror M3, and the second end of the hole H2 at the curved surface of the auxiliary tool 40 can face downward toward the entrance mirror M4. Once the radiation beam R4 propagates toward the auxiliary tool 40, a portion of the radiation beam R4 can pass through the hole H2 of the auxiliary tool 40, while another portion of the radiation beam R4 can be incident on the flat surface of the auxiliary tool 40 and generate a light spot LS2 on the flat surface of the auxiliary tool 40. Based on the relationship between the light spot LS2 and the hole H2 of the auxiliary tool 40, the propagation path of the radiation beam R4 can be determined, which will be discussed in more detail later.

[0131] Figures 8A-8B Different cases of determining the propagation path of the radiation beam are illustrated according to some embodiments of the present disclosure. In more detail, Figure 8A for the case that the propagation path of the radiation beam R4 is along the predetermined propagation path, Figure 8B for the case that the propagation path of the radiation beam R4 deviates from the predetermined propagation path.

[0132] The first example of determining the propagation path of the radiation beam R4 includes comparing the position of the center C3 of the hole H2 with the position of the center C4 of the light spot LS2. If the center C3 of the hole H2 overlaps with the center C4 of the light spot LS2, the propagation path of the radiation beam R4 is determined to be along the predetermined propagation path. For example, in Figure 8A , the center C3 of the hole H2 overlaps with the center C4 of the light spot LS2. However, if the center C3 of the hole H2 does not overlap with the center C4 of the light spot LS2, the propagation path of the radiation beam R4 is determined to deviate from the predetermined propagation path. For example, in Figure 8B , the center C3 of the hole H2 does not overlap with the center C4 of the light spot LS2.

[0133] A second example of determining the propagation path of the radiation beam R4 involves comparing the distances between the boundary of the aperture H2 and the boundary of the spot LS2. For example, along a first line L3 that runs along the length of the auxiliary tool 40 and through the center C3 of the aperture H2, the first end of the boundary of the aperture H2 and the boundary of the spot LS2 share a shortest distance S21, and the second end of the boundary of the aperture H2 and the boundary of the spot LS2 share a shortest distance S22, where the first end and the second end are opposite each other. Conversely, along a second line L4 that runs perpendicular to the length of the auxiliary tool 40 and through the center C3 of the aperture H2, the first end of the boundary of the aperture H2 and the boundary of the spot LS2 share a shortest distance S23, and the second end of the boundary of the aperture H2 and the boundary of the spot LS2 share a shortest distance S24.

[0134] If distances S21 and S22 are substantially the same, and distances S23 and S24 are substantially the same, then the propagation path of the radiation beam R4 is determined to be along a predetermined propagation path. For example, in Figure 8A In this context, distances S21 and S22 are substantially the same, and distances S23 and S24 are substantially the same. However, if distance S21 differs from distance S22 and / or distance S23 differs from distance S24, the propagation path of the radiation beam R4 is determined to have deviated from the predetermined propagation path. For example, in... Figure 8B In the distance S21, the distance S22 is different from the distance S23, and the distance S23 is different from the distance S24.

[0135] Figure 9 This is a method for replacing the illumination source of a wafer inspection system according to some embodiments. A method 1000 is provided, as described above, combining... Figures 8B-9 Discussion Figure 9 Method 1000. Although method 1000 is described as a series of actions, it should be understood that these actions are not limiting, that is, the order of the actions may be changed in other embodiments. In other embodiments, some of the actions shown and / or described may be omitted in whole or in part.

[0136] Method 1000 begins with operation S101, which involves performing inspection processing on the wafer using a wafer inspection system. More specifically, the wafer W can be loaded into the wafer loading port 210 of the wafer inspection tool 200 of the wafer inspection system 20 and placed on a wafer stage (not shown). Then, as... Figure 1 As shown, a wafer inspection optical system 10 is used to perform an inspection process on wafer W. For example, as... Figure 1As shown, illumination source 100 generates a radiation beam that is directed to the surface of wafer W. The radiation beam illuminates defects on the surface of wafer W, and the radiated light is scattered from the point of incidence. The scattered light is then collected by a light multiplier tube 130, which amplifies the optical signal and generates a corresponding electrical output. The output of light multiplier tube 130 is digitized by an analog-to-digital converter (not shown). The location of particles (e.g., defect locations) on wafer W can then be determined based on the collected radiation.

[0137] By replacing the existing lighting source with a new lighting source, method 1000 proceeds to operation S102. As described above, the lighting source (e.g., Figure 1 The average lifespan of the illumination source 100 is approximately 10 to 12 months. That is, after several inspection processes, the performance of the illumination source may become unsatisfactory. For example, the intensity of the radiation beam may be insufficient, potentially affecting inspection quality. Therefore, the existing illumination source will be replaced with a new one. For example, the existing illumination source 100 can be removed from the wafer inspection tool 200 (see [link to relevant documentation]). Figure 2 Next, the new lighting source 100 is installed in the wafer inspection tool 200.

[0138] By determining whether the first propagation path of the radiation beam is along the first predetermined propagation path, method 1000 proceeds to operation S103. In some embodiments, once the new illumination source 100 is installed in the wafer inspection tool 200, the new illumination source 100 may not be in the correct position, and therefore the radiation beam generated from the new illumination source 100 may not be aimed at the correct orientation.

[0139] In some embodiments, determining whether the first propagation path of the radiation beam is along a first predetermined propagation path includes using an auxiliary tool 30 (see...). Figures 3A-3D The propagation path of the radiation beam R2 is determined by this. For example, the auxiliary tool 30 is fixed to the fixing plate 220 in the wafer inspection tool 200 (see...). Figure 4A and Figure 4B Next, the new lighting source 100 is operated to generate a radiation beam, and the auxiliary tool 30 is used to determine the propagation path of the radiation beam R2. (See above for reference.) Figure 5A and Figure 5B The details of determining the propagation path of the radiation beam R2 were discussed, and for the sake of brevity, they will not be repeated here.

[0140] If the propagation path of the radiation beam R2 is not along the predetermined propagation path, the method proceeds to operation S104 by adjusting at least one component in the wafer inspection system. For example, the position of the new illumination source 100 can be modified to change the propagation path of the radiation beam generated from the new illumination source 100. Such modification can adjust the propagation path of the radiation beam R2. Then, the method returns to operation S103. In some embodiments, during the modification of the position of the new illumination source 100, the auxiliary tool 30 can be placed on the fixing plate 220 to observe how the propagation path of the radiation beam R2 changes. This will facilitate obtaining the correct propagation path of the radiation beam R2.

[0141] If the propagation path of the radiation beam R2 is along the predetermined propagation path, the method proceeds to operation S105 by determining whether the second propagation path of the radiation beam is along a second predetermined propagation path. In some embodiments, determining whether the second propagation path of the radiation beam is along the second predetermined propagation path comprises using the auxiliary tool 40 (see Figures 6A-6D ) to determine the propagation path of the radiation beam R4. For example, the auxiliary tool 40 is fixed on a fixing plate 222 (see Figure 7A and Figure 7B ) in the wafer inspection tool 200. Then, the new illumination source 100 is operated to generate a radiation beam, and the auxiliary tool 40 is used to determine the propagation path of the radiation beam R4. Details of determining the propagation path of the radiation beam R4 have been discussed above with reference to Figure 8A and Figure 8B and will not be repeated here for brevity.

[0142] If the propagation path of the radiation beam R4 is not along the predetermined propagation path, the method proceeds to operation S106 by adjusting at least one component in the wafer inspection system. For example, the position of the scanning mirror M2 can be modified to change the propagation path of the radiation beam R3 (see Figure 1 ). Such modification can also adjust the propagation path of the radiation beam R4. Then, the method 1000 can return to operation S105. In some embodiments, during the modification of the position of the scanning mirror M2, the auxiliary tool 40 can be placed on the fixing plate 222 to observe how the propagation path of the radiation beam R4 changes. This will facilitate obtaining the correct propagation path of the radiation beam R4.

[0143] If the propagation path of the radiation beam R4 is along the predetermined propagation path, the method returns to operation S101. In more detail, the wafer W is subjected to the inspection process using the new illumination source 100. It should be understood that the auxiliary tool 30 and the auxiliary tool 40 can be removed from the wafer inspection tool 200 before operation S101 is performed again.

[0144] It is understood that the auxiliary tool 30 is fixed on the fixing plate 220 during operations S103 and S104, while the auxiliary tool 40 used during operations S105 and S106 can not be fixed on the fixing plate 222. If the auxiliary tool 40 is fixed on the fixing plate 222 during operations S103 and S104, the auxiliary tool 40 can block the propagation path of the radiation beam. Therefore, the auxiliary tool 40 (if present) will be removed from the fixing plate 222 before operations S103 and S104 are performed. Similarly, during operations S105 and S106, the auxiliary tool 40 is fixed on the fixing plate 222, while the auxiliary tool 30 used in operations S103 and S104 can not be fixed on the fixing plate 220. If the auxiliary tool 30 is fixed on the fixing plate 220 during operations S105 and S106, the auxiliary tool 30 can block the propagation path of the radiation beam. Therefore, the auxiliary tool 30 (if present) will be removed from the fixing plate 220 before operations S105 and S106 are performed.

[0145] In other embodiments, if the auxiliary tool 30 does not affect the propagation path of the radiation beam during operations S105 and S106, and the auxiliary tool 40 does not affect the propagation path of the radiation beam during operations S103 and S104, both auxiliary tools 30 and 40 can be fixed on the fixing plates 220 and 222, respectively, during operations S103, S104, S105, and S106.

[0146] In some embodiments, the auxiliary tools 30 and 40 can be detached from the fixing plates 220 and 222, respectively. Therefore, during the performance of the detection process (e.g., operation S101), the auxiliary tools 30 and 40 can be removed from the fixing plates 220 and 222, respectively. However, in other embodiments, during the performance of the detection process (e.g., operation S101), the auxiliary tools 30 and 40 can be fixed on the fixing plates 220 and 222, respectively. This is because if the propagation path is correct, the radiation beam can still pass through the hole H1 of the auxiliary tool 30 and the hole H2 of the auxiliary tool 40.

[0147] Figure 10A and Figure 10B FIG. 1 illustrates the relationship between the auxiliary tools and the fixing plates according to some embodiments of the present disclosure. Figure 10A and Figure 10B respectively. Figure 4A and Figure 7A Similarities have been discussed in Figure 4A and Figure 7A Some elements in Figure 10A and Figure 10B will not be repeated for brevity.

[0148] In Figure 10AThe image capture device 230 is shown in the wafer inspection tool 200 of the wafer inspection system 20. In some embodiments, the image capture device 230 is a camera, an image sensor, or other suitable image capture device. In some embodiments, the image capture device 230 is used to capture an image of the flat surface of the auxiliary tool 30. Specifically, as shown... Figure 9 As shown, during operation S103, the image capturing device 230 is capable of capturing an image including the aperture H1 of the auxiliary tool 30 and the light spot LS1 on the flat surface of the auxiliary tool 30. In some embodiments, the captured image can be sent to a computer system (e.g., Figure 11 The computer system 240 can automatically calculate the position (or shape) of the hole H1 and the light spot LS1, and can determine whether the propagation path of the radiation beam R2 is along the predetermined propagation path.

[0149] Similarly, in Figure 10B The image capture device 232 is shown in the wafer inspection tool 200 of the wafer inspection system 20. In some embodiments, the image capture device 232 is a camera, an image sensor, or other suitable image capture device. In some embodiments, the image capture device 232 is used to capture an image of the flat surface of the auxiliary tool 40. Specifically, as shown in the image capture device 232, the image capture device 232 is used to capture an image of the flat surface of the auxiliary tool 40. Figure 9 As shown, during operation S105, the image capturing device 232 is capable of capturing images including the aperture H2 of the auxiliary tool 40 and the light spot LS2 on the flat surface of the auxiliary tool 40. In some embodiments, the captured images can be sent to a computer system (not shown), and the computer system can automatically calculate the position (or shape) of the aperture H2 and the light spot LS2, and determine whether the propagation path of the radiation beam R4 is along a predetermined propagation path.

[0150] Figure 11 This is a block diagram of a wafer inspection system according to some embodiments of the present disclosure. The wafer inspection system 20 includes a wafer inspection tool 200. The wafer inspection system 20 also includes a wafer inspection optical system 10, an input device 202, an output device 204, image capturing devices 230 and 232, and a computer system 240. In some embodiments, the computer system 240 can electrically communicate with the wafer inspection optical system 10, the input device 202, the output device 204, and the image capturing devices 230 and 232.

[0151] In some embodiments, computer system 240 may be a controller and a computer-readable storage medium encoding (i.e., storing) computer program code (i.e., a set of executable instructions). The controller is electrically coupled to the computer-readable storage medium. The controller is configured to execute the computer program code encoded in the computer-readable storage medium to enable computer system 240 to perform the above-described... Figure 9 The operation of the discussion.

[0152] In some embodiments, the controller is a central processing unit (CPU), a multi-processor, a distributed processing system, an application specific integrated circuit (ASIC), and / or suitable processing unit. In some embodiments, the computer readable storage medium includes a semiconductor or solid state memory, magnetic tape, a removable computer diskette, a random access memory (RAM), a read-only memory (ROM), a rigid disk, and / or an optical disk. In some embodiments using an optical disk, the computer readable storage medium includes a compact disk-read only memory (CD-ROM), a compact disk-read / write (CD-R / W), and / or a digital video disc (DVD).

[0153] According to the above embodiments, it can be seen that the present disclosure has advantages in manufacturing integrated circuits. However, it should be understood that other embodiments can provide additional advantages, not all advantages necessarily need to be disclosed herein, and no particular advantage needs to be used for all embodiments. Embodiments of the present disclosure provide a wafer detection system and method thereof, by using at least one beam inspection tool to determine whether a radiation beam propagates along a predetermined propagation path, and when the radiation beam deviates from the predetermined propagation path, the propagation path thereof can be adjusted. By using such a configuration, the detection performance can be improved.

[0154] In some embodiments of the present disclosure, a method includes performing a first wafer detection process using an illumination source in a wafer detection tool; replacing the illumination source with a new illumination source; generating a radiation beam from the new illumination source; placing an auxiliary tool along a propagation path of the radiation beam, wherein the auxiliary tool has an aperture, and wherein the radiation beam generates a spot around the aperture of the auxiliary tool; determining whether the propagation path of the radiation beam is along a predetermined propagation path based on a position of the aperture and a position of the spot; and in response to determining that the propagation path of the radiation beam is along the predetermined propagation path, performing a second wafer detection process using the new illumination source.

[0155] In some embodiments, the auxiliary tool includes a fixed portion and a body portion connected to the fixed portion and having a flat surface, wherein the spot is generated on the flat surface of the body portion.

[0156] In some embodiments, positioning the auxiliary tool along the propagation path of the radiation beam includes securing the auxiliary tool on a securing plate in the wafer inspection tool by inserting a securing portion of the auxiliary tool into a securing hole of the securing plate.

[0157] In some embodiments, the flat surface faces upward during determining whether the propagation path of the radiation beam is along the predetermined propagation path.

[0158] In some embodiments, the method further includes adjusting a position of the illumination source in response to determining that the propagation path of the radiation beam deviates from the predetermined propagation path.

[0159] In some embodiments, determining whether the propagation path of the radiation beam is along the predetermined propagation path includes comparing a first shortest distance between a first end of the hole along a line through a center of the hole to a boundary of the spot and a second shortest distance between a second end of the hole along the line through the center of the hole to the boundary of the spot, and wherein the propagation path of the radiation beam is determined to be along the predetermined propagation path when the first shortest distance is substantially the same as the second shortest distance.

[0160] In some embodiments, determining whether the propagation path of the radiation beam is along the predetermined propagation path includes comparing a position of a center of the hole of the auxiliary tool to a position of a center of the spot, and wherein the propagation path of the radiation beam is determined to be along the predetermined propagation path when the center of the hole of the auxiliary tool overlaps the center of the spot.

[0161] In some embodiments, the method further includes removing the auxiliary tool from the wafer inspection tool prior to performing the second wafer inspection process.

[0162] In some embodiments of the present disclosure, a method includes generating a radiation beam from an illumination source in a wafer inspection tool; positioning a first auxiliary tool along a first propagation path of the radiation beam, wherein the first auxiliary tool has a first hole, and wherein the radiation beam generates a first spot around the first hole of the first auxiliary tool; determining whether the first propagation path of the radiation beam is along a first predetermined propagation path based on a position of the first hole and a position of the first spot; positioning a second auxiliary tool along a second propagation path of the radiation beam in response to determining that the first propagation path of the radiation beam is along the first predetermined propagation path, wherein the second auxiliary tool has a second hole, and wherein the radiation beam generates a second spot around the second hole of the second auxiliary tool; determining whether the second propagation path of the radiation beam is along a second predetermined propagation path based on a position of the second hole and a position of the second spot; and performing a wafer inspection process using the illumination source in response to determining that the second propagation path of the radiation beam is along the second predetermined propagation path.

[0163] In some embodiments, the first hole and the second hole have different shapes.

[0164] In some embodiments, the first aperture has a circular shape, and the second aperture has a strip shape with rounded opposite ends.

[0165] In some embodiments, the second auxiliary tool is at a lower level than the first auxiliary tool.

[0166] In some embodiments, the method further comprises removing the first auxiliary tool before placing the second auxiliary tool along the second propagation path of the radiation beam.

[0167] In some embodiments, the method further comprises adjusting the position of the illumination source in response to determining that the first propagation path of the radiation beam deviates from the first predetermined propagation path.

[0168] In some embodiments, the first auxiliary tool and the second auxiliary tool each comprise a fixed portion and a body portion connected to the fixed portion, the body portion comprising a first segment and a second segment, the second segment of the body portion being connected to the fixed portion, wherein the fixed portion and the second segment of the body portion comprise a cylindrical shape, and the first segment of the body portion comprises a semi-cylindrical shape.

[0169] In some embodiments of the disclosure, a wafer inspection system comprises a wafer inspection tool. An illumination source is in the wafer inspection tool and configured to generate a radiation beam. A first optical element and a second optical element are in the wafer inspection tool and optically coupled to the illumination source, wherein the first optical element directs the radiation beam toward the second optical element. A first beam inspection tool is between the first optical element and the second optical element, wherein the first beam inspection tool comprises a first aperture, and the radiation beam propagates through the first aperture of the first beam inspection tool.

[0170] In some embodiments, the wafer inspection system further comprises a first fixed plate in the wafer inspection tool, wherein the first beam inspection tool is fixed on the first fixed plate and detachable from the first fixed plate.

[0171] In some embodiments, the first beam inspection tool comprises an upward-facing flat surface, and the first aperture is at the flat surface of the first beam inspection tool.

[0172] In some embodiments, the wafer inspection system further comprises a third optical element and a fourth optical element in the wafer inspection tool and optically coupled to the illumination source, wherein the second optical element directs the radiation beam toward the third optical element, and the third optical element directs the radiation beam toward the fourth optical element. A second beam inspection tool is between the third optical element and the fourth optical element, wherein the second beam inspection tool comprises a second aperture, and the radiation beam propagates through the second aperture of the second beam inspection tool.

[0173] In some embodiments, the first aperture of the first beam inspection tool and the second aperture of the second beam inspection tool have different shapes.

[0174] In some embodiments, the first hole has a circular shape, and the second hole has a strip shape with rounded opposite ends.

[0175] In some embodiments of the disclosure, a wafer inspection system includes a wafer inspection tool. An illumination source is in the wafer inspection tool and is configured to generate a radiation beam. A first optical element and a second optical element are in the wafer inspection tool and optically coupled with the illumination source, wherein the first optical element directs the radiation beam toward the second optical element. A first fixed plate is in the wafer inspection tool. A first beam inspection tool is fixed on the first fixed plate, wherein the radiation beam propagates through the first beam inspection tool.

[0176] In some embodiments, the first beam inspection tool includes a fixed portion inserted in a fixed hole of the first fixed plate, and a main portion coupled to the fixed portion and having a hole, wherein the radiation beam propagates through the hole of the first beam inspection tool.

[0177] In some embodiments, the main portion has an upwardly facing flat surface.

[0178] In some embodiments, the radiation beam generates a spot on the flat surface of the main portion.

[0179] In some embodiments, the first beam inspection tool is detachable from the first fixed plate.

[0180] In some embodiments, the wafer inspection system further includes a third optical element and a fourth optical element in the wafer inspection tool and optically coupled with the illumination source, wherein the second optical element directs the radiation beam toward the third optical element, and the third optical element directs the radiation beam toward the fourth optical element. A second fixed plate is in the wafer inspection tool. A second beam inspection tool is fixed on the second fixed plate, wherein the radiation beam propagates through the first beam inspection tool, and wherein the first beam inspection tool has a first hole, the second beam inspection tool has a second hole, and the first hole and the second hole have different shapes.

[0181] In some embodiments of the disclosure, a wafer inspection system includes a wafer inspection tool. An illumination source is in the wafer inspection tool and is configured to generate a radiation beam. A first optical element and a second optical element are in the wafer inspection tool and optically coupled with the illumination source. A first beam inspection tool is between the first optical element and the second optical element, wherein the first beam inspection tool includes a first hole, and the first optical element and the second optical element are optically coupled through the first hole of the first beam inspection tool.

[0182] In some embodiments, further including a first fixed plate in the wafer inspection tool, wherein the first beam inspection tool is fixed on the first fixed plate and is detachable from the first fixed plate.

[0183] In some embodiments, the first beam inspection tool includes an upwardly facing planar surface, and the first aperture is at the planar surface of the first beam inspection tool.

[0184] In some embodiments, further comprising a third optical element and a fourth optical element in the wafer inspection tool and optically coupled with the illumination source. The second beam inspection tool is between the third optical element and the fourth optical element, wherein the second beam inspection tool includes a second aperture, and the third optical element and the fourth optical element are optically coupled via the second aperture of the second beam inspection tool.

[0185] In some embodiments, the first aperture of the first beam inspection tool and the second aperture of the second beam inspection tool have different shapes.

[0186] In some embodiments, the first aperture has a circular shape, and the second aperture has a strip shape with rounded opposite ends.

[0187] In some embodiments of the present disclosure, a wafer inspection system includes a wafer inspection tool. An illumination source is in the wafer inspection tool and is configured to generate a beam of radiation. A first optical element and a second optical element are in the wafer inspection tool and are optically coupled with the illumination source. A first fixed plate is in the wafer inspection tool. A first beam inspection tool is fixed on the first fixed plate, wherein the first optical element and the second optical element are optically coupled via the first beam inspection tool.

[0188] In some embodiments, the first beam inspection tool includes a fixed portion inserted into a fixed aperture of the first fixed plate, and a body portion coupled to the fixed portion and having an aperture, wherein the first optical element and the second optical element are optically coupled via the aperture of the first beam inspection tool.

[0189] In some embodiments, the body portion has an upwardly facing planar surface.

[0190] In some embodiments of the present disclosure, a wafer inspection system includes a wafer inspection tool. An illumination source is in the wafer inspection tool and is configured to generate a beam of radiation. A first optical element and a second optical element are in the wafer inspection tool and are optically coupled with the illumination source. A first beam inspection tool is between the first optical element and the second optical element, wherein the first beam inspection tool includes a first aperture, and the first optical element and the second optical element are optically coupled via the first aperture of the first beam inspection tool, wherein the first beam inspection tool includes an upwardly facing planar surface, and the first aperture is at the planar surface of the first beam inspection tool.

[0191] The foregoing outlines features of several embodiments so that a thorough comprehension of the disclosure can be attained. Those skilled in the art should appreciate that they can readily use the disclosure as a basis for designing or modifying other processes and structures for carrying out the same purposes and / or achieving the same advantages of the embodiments introduced herein. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the disclosure, and that they can make various changes, substitutions, and alterations herein without departing from the spirit and scope of the disclosure.

Claims

1. A wafer inspection system, characterized by, A wafer inspection tool; An illumination source in the wafer inspection tool and configured to generate a radiation beam; A first optical element and a second optical element in the wafer inspection tool and optically coupled with the illumination source; and A first beam inspection tool between the first optical element and the second optical element, wherein the first beam inspection tool comprises a first aperture, and the first optical element and the second optical element are optically coupled via the first aperture of the first beam inspection tool.

2. The wafer inspection system of claim 1, further comprising a first fixing plate in the wafer inspection tool, wherein the first beam inspection tool is fixed on the first fixing plate and detachable from the first fixing plate. wherein the first beam inspection tool comprises an upward-facing flat surface, and the first aperture is at the flat surface of the first beam inspection tool.

3. The wafer inspection system of claim 1, wherein, further comprising:

4. The wafer inspection system of claim 1, wherein, a third optical element and a fourth optical element in the wafer inspection tool and optically coupled with the illumination source; and a second beam inspection tool between the third optical element and the fourth optical element, wherein the second beam inspection tool comprises a second aperture, and the third optical element and the fourth optical element are optically coupled via the second aperture of the second beam inspection tool. wherein the first aperture of the first beam inspection tool and the second aperture of the second beam inspection tool have different shapes.

5. The wafer inspection system of claim 4, wherein, wherein the first aperture has a circular shape, and the second aperture has a strip shape with rounded opposite ends.

6. The wafer inspection system of claim 5, wherein, A wafer inspection tool; 7. A wafer inspection system, characterized by, An illumination source in the wafer inspection tool and configured to generate a radiation beam; A first optical element and a second optical element in the wafer inspection tool and optically coupled with the illumination source; a first fixing plate in the wafer inspection tool; and a first beam inspection tool fixed on the first fixing plate, wherein the first optical element and the second optical element are optically coupled via the first beam inspection tool. wherein the first beam inspection tool comprises: a fixing portion inserted into a fixing aperture of the first fixing plate; and 8. The wafer inspection system of claim 7, wherein, a main body portion coupled to the fixing portion and having an aperture, wherein the first optical element and the second optical element are optically coupled via the aperture of the first beam inspection tool. wherein the main body portion has an upward-facing flat surface. A wafer inspection tool; 9. The wafer inspection system of claim 8, wherein, An illumination source in the wafer inspection tool and configured to generate a radiation beam; 10. A wafer inspection system, characterized by, A first optical element and a second optical element in the wafer inspection tool and optically coupled with the illumination source; and A first beam inspection tool between the first optical element and the second optical element, wherein the first beam inspection tool comprises a first aperture, and the first optical element and the second optical element are optically coupled via the first aperture of the first beam inspection tool, wherein the first beam inspection tool comprises an upward-facing flat surface, and the first aperture is at the flat surface of the first beam inspection tool. ​ ​ ​

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