Optical detection device

Abstract

The utility model discloses an optical detection device. The optical detection device provided by the utility model comprises an infrared band expansion camera, an infrared band expansion microscope tube, an infrared band expansion objective lens, a chuck, a coaxial illumination light source, a rotating wheel and a wafer to be detected, the infrared band expansion camera is connected with the infrared band expansion microscope tube, the rotating wheel is arranged below the infrared band expansion microscope tube, the infrared band expansion objective lens is arranged below the rotating wheel, the coaxial illumination light source is arranged on one side of the infrared band expansion microscope tube, and the chuck is arranged below the infrared band expansion objective lens. A to-be-detected wafer is arranged on the chuck, along with movement of the chuck, the infrared band extension camera triggers photographing according to a set frequency, the coaxial illumination light source triggers stroboflash according to the set frequency, information of the front face and the back face of the to-be-detected wafer is obtained at the same time, the device is simple in structure, and the detection accuracy is improved under the condition that the warping degree of the wafer is not increased. And a visible light band and an infrared band can be compatible simultaneously.

Description

Technical Field

[0001] This utility model relates to the field of semiconductor technology, and in particular to an optical detection device. Background Technology

[0002] In wafer fabrication, visual inspection is required to ensure that the final wafer defects are within the factory allowable range. However, some products require simultaneous inspection of both sides or non-surface defects. Conventional bright-field inspection methods cannot perform two-sided inspection and surface penetration inspection, while conventional infrared inspection methods are difficult to implement in wafer fabrication equipment structures. Therefore, a simple structure compatible with both visible light and infrared optical inspection methods is needed.

[0003] Conventional infrared and visible light compatible inspection devices typically consist of a front-facing visible light microscopic imaging optical inspection device, a rear-facing infrared inspection device, a hollowed-out chuck design, an infrared light source added to the back, and a front-facing infrared inspection device. Existing solutions have complex structures, requiring modifications to the chuck and the addition of a rear-facing wafer inspection device. This modification increases costs and design complexity. Furthermore, the hollowed-out design weakens the wafer's adhesion, increasing wafer warpage and causing the original depth of field to fail to cover the warpage, resulting in defocusing.

[0004] The above content is only used to help understand the technical solution of this utility model and does not represent an admission that the above content is prior art. Utility Model Content

[0005] The main objective of this invention is to provide an optical detection device that addresses the technical problems of existing conventional infrared and visible light detection devices, such as complex structure, high cost, and susceptibility to defocusing.

[0006] To achieve the above objectives, this utility model provides an optical detection device, the optical detection device comprising:

[0007] Infrared band extended camera (100), infrared band extended microscope tube (200), infrared band extended objective lens (300), clamp (400), coaxial illumination source (500), rotating wheel (600), wafer to be inspected (800);

[0008] The infrared band extension camera (100) is connected to the infrared band extension microscope tube (200). The rotating wheel (600) is located below the infrared band extension microscope tube (200). The infrared band extension objective lens (300) is located below the rotating wheel (600). The coaxial illumination source (500) is located on one side of the infrared band extension microscope tube (200). The clamping plate (400) is located below the infrared band extension objective lens (300). The wafer to be inspected (800) is located on the clamping plate (400).

[0009] The coaxial illumination source (500) generates visible light, which is reflected by the beam splitter inside the infrared band extended microscope tube (200), passes through the infrared band extended objective lens (300), and reaches the wafer to be inspected (800). The visible light undergoes specular reflection on the wafer to be inspected (800), passes through the infrared band extended objective lens (300) and the infrared band extended microscope tube (200), and returns to the infrared band extended camera (100) for imaging.

[0010] The coaxial illumination source (500) generates infrared light. The infrared light is reflected by the beam splitter inside the infrared band extended microscope tube (200), passes through the infrared band extended objective lens (300), and reaches the wafer to be tested (800). Part of the light is specularly reflected on the wafer to be tested (800), passes through the infrared band extended objective lens (300) and the infrared band extended microscope tube (200), and returns to the infrared band extended camera (100). Part of the light passes through the wafer to be tested (800), is reflected on the clamping plate (400), passes through the wafer to be tested (800) again, passes through the infrared band extended objective lens (300) and the infrared band extended microscope tube (200), and returns to the infrared band extended camera (100) for imaging.

[0011] As the clamp (400) moves, the infrared band extension camera (100) is triggered to take pictures at a set frequency, and the coaxial illumination source (500) is triggered to strobe at the set frequency, so as to simultaneously acquire information on both sides of the wafer (800) to be tested.

[0012] Preferably, the optical detection device further includes a ring light source (700);

[0013] The ring light source (700) is a ring light used to provide dark field illumination to detect bump and pit defects in the wafer (800) to be inspected.

[0014] Preferably, the rotary wheel (600) is used to switch between different magnification objectives.

[0015] Preferably, the chuck (400) is a microporous adsorption type chuck with a silver surface.

[0016] Preferably, the spectral response range of the infrared band extended camera (100) includes the visible spectrum and the infrared spectrum.

[0017] Preferably, the transmission bands of the infrared extended microscope tube (200) and the infrared extended objective lens (300) both include the visible light band and the infrared band.

[0018] Preferably, the magnification of the infrared band extension objective (300) is adjusted by the rotary wheel (600) according to the product testing accuracy requirements. The magnification of the infrared band extension objective (300) includes 2x, 5x or 10x.

[0019] In this invention, the optical detection device includes: an infrared extended camera (100), an infrared extended microscope tube (200), an infrared extended objective lens (300), a clamping plate (400), a coaxial illumination source (500), a rotating wheel (600), and a wafer to be inspected (800); the infrared extended camera (100) is connected to the infrared extended microscope tube (200), the rotating wheel (600) is disposed below the infrared extended microscope tube (200), the infrared extended objective lens (300) is disposed below the rotating wheel (600), and the coaxial illumination source (500) is disposed below the rotating wheel (600). A light source (500) is positioned on one side of the infrared extended microscope tube (200), a clamping plate (400) is positioned below the infrared extended objective lens (300), and the wafer to be inspected (800) is positioned above the clamping plate (400). The coaxial illumination light source (500) generates visible light, which is reflected by a beam splitter inside the infrared extended microscope tube (200), passes through the infrared extended objective lens (300), and reaches the wafer to be inspected (800). Specular reflection occurs on the wafer to be inspected (800), and the light passes through the infrared extended objective lens (300) and the... The infrared extended microscope tube (200) returns to the infrared extended camera (100) for imaging; the coaxial illumination source (500) generates infrared light, which is reflected by the beam splitter inside the infrared extended microscope tube (200), passes through the infrared extended objective lens (300), and reaches the wafer to be inspected (800). Part of the light undergoes specular reflection on the wafer to be inspected (800), passing through the infrared extended objective lens (300) and the infrared extended microscope tube (200) back to the infrared extended camera (100). (00) Part of the light passes through the wafer to be inspected (800), is reflected on the chuck (400), and passes through the wafer to be inspected (800) again, passing through the infrared band extension objective lens (300) and the infrared band extension microscope tube (200) back to the infrared band extension camera (100) for imaging; as the chuck (400) moves, the infrared band extension camera (100) is triggered to take pictures at a set frequency, and the coaxial illumination source (500) is triggered to strobe at the set frequency, so as to simultaneously acquire information on both sides of the wafer to be inspected (800). The optical inspection device has a simple structure, can be compatible with both visible light and infrared bands without increasing the degree of wafer warping, has low cost, and can simultaneously inspect both sides of the wafer without easily losing focus. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the structure of an optical detection device in one embodiment of the present invention.

[0022] Explanation of icon numbers:

[0023] label name label name 100 Infrared band extended camera 200 Infrared band extended microscope tube 300 Infrared band extended objective 400 Clamp 500 coaxial lighting source 600 Rotary wheel 700 Ring light source 800 Wafer under inspection

[0024] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0025] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0026] It should be noted that if the embodiments of this utility model involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0027] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of indicated technical features. Therefore, features defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0028] Reference Figure 1 , Figure 1 This is a schematic diagram of an embodiment of an optical detection device according to the present invention.

[0029] like Figure 1 As shown, the optical detection device includes:

[0030] Infrared band extended camera (100), infrared band extended microscope tube (200), infrared band extended objective lens (300), clamp (400), coaxial illumination source (500), rotating wheel (600), wafer to be inspected (800);

[0031] The infrared band extension camera (100) is connected to the infrared band extension microscope tube (200). The rotating wheel (600) is located below the infrared band extension microscope tube (200). The infrared band extension objective lens (300) is located below the rotating wheel (600). The coaxial illumination source (500) is located on one side of the infrared band extension microscope tube (200). The clamping plate (400) is located below the infrared band extension objective lens (300). The wafer to be inspected (800) is located on the clamping plate (400).

[0032] The coaxial illumination source (500) generates visible light, which is reflected by the beam splitter inside the infrared band extended microscope tube (200), passes through the infrared band extended objective lens (300), and reaches the wafer to be inspected (800). The visible light undergoes specular reflection on the wafer to be inspected (800), passes through the infrared band extended objective lens (300) and the infrared band extended microscope tube (200), and returns to the infrared band extended camera (100) for imaging.

[0033] The coaxial illumination source (500) generates infrared light. The infrared light is reflected by the beam splitter inside the infrared band extended microscope tube (200), passes through the infrared band extended objective lens (300), and reaches the wafer to be tested (800). Part of the light is specularly reflected on the wafer to be tested (800), passes through the infrared band extended objective lens (300) and the infrared band extended microscope tube (200), and returns to the infrared band extended camera (100). Part of the light passes through the wafer to be tested (800), is reflected on the clamping plate (400), passes through the wafer to be tested (800) again, passes through the infrared band extended objective lens (300) and the infrared band extended microscope tube (200), and returns to the infrared band extended camera (100) for imaging.

[0034] As the clamp (400) moves, the infrared band extension camera (100) is triggered to take pictures at a set frequency, and the coaxial illumination source (500) is triggered to strobe at the set frequency, so as to simultaneously acquire information on both sides of the wafer (800) to be tested.

[0035] It should be understood that the optical inspection device in this embodiment has a simple structure, is compatible with both visible and infrared light bands, and can simultaneously inspect both sides of a wafer. The coaxial illumination source (500) generates both visible and infrared light. The visible light generated by the coaxial illumination source (500) is reflected by the beam splitter (BS mirror) inside the infrared band extended microscope tube (200), passes through the infrared band extended objective lens (300), and reaches the wafer (800) to be inspected. Specular reflection occurs on the wafer (800), and the light passes through the infrared band extended objective lens (300) and the infrared band extended microscope tube (200) back to the infrared band extended camera (100), where it is imaged. The surface appearance of the wafer is imaged into the infrared band extended camera (100).

[0036] The coaxial illumination source (500) generates infrared light. This infrared light is reflected by a beam splitter within the infrared extended microscope tube (200), passes through the infrared extended objective lens (300), and reaches the wafer (800) to be inspected. Part of the light undergoes specular reflection on the wafer (800), passing through the infrared extended objective lens (300) and the infrared extended microscope tube (200) back to the infrared extended camera (100). Another portion of the light passes through the wafer (800), is reflected by the clamping plate (400), and then passes through the wafer (800) again, passing through the infrared extended objective lens (300) and the infrared extended microscope tube (200) back to the infrared extended camera (100) for imaging. The surface appearance of the wafer is then imaged into the infrared extended camera (100).

[0037] The infrared band extended camera (100) can simultaneously receive the appearance information of the front and back sides of the wafer. As the clamp (400) moves, the infrared band extended camera (100) is triggered to take pictures at a set frequency, and the coaxial illumination source (500) is triggered to strobe at the same frequency. In this way, information of both the front and back sides of the wafer can be acquired simultaneously during the flying shooting process, thereby realizing the detection of both the front and back sides of the wafer.

[0038] Furthermore, in this embodiment, the optical inspection device further includes a ring light source (700); the ring light source (700) is a ring light used to provide dark field illumination to detect bump and pit defects in the wafer (800) to be inspected.

[0039] It should be noted that the ring light source (700) is a ring light that can provide dark field illumination, detect bump and pit defects, and filter point defects (particles) on the wafer.

[0040] Furthermore, in this embodiment, the rotary wheel (600) is used to switch between different magnification objectives.

[0041] Furthermore, in this embodiment, the clamp (400) is a microporous adsorption type clamp with a silver surface.

[0042] It should be understood that the chuck (400) is a microporous adsorption type chuck with a silver surface instead of black. The chuck surface has a high reflectivity, which can better reflect light.

[0043] Furthermore, the spectral response range of the infrared band extended camera (100) includes the visible spectrum and the infrared spectrum.

[0044] Furthermore, the transmission bands of the infrared band extended microscope tube (200) and the infrared band extended objective lens (300) both include the visible light band and the infrared band.

[0045] Furthermore, in this embodiment, the magnification of the infrared band extension objective (300) is adjusted by the rotary wheel (600) according to the product detection accuracy requirements. The magnification of the infrared band extension objective (300) includes 2x, 5x or 10x.

[0046] In a specific implementation, the transmission band of the infrared band extended microscope tube (200) and the infrared band extended objective lens (300) includes the visible light band of 400nm-700nm and extends to the infrared band, so that it can receive light in both visible and infrared bands. The magnification of the infrared band extended objective lens (300) can be adjusted to 2x, 5x, 10x, etc., according to the product detection accuracy requirements, and can be switched in real time through the rotary wheel (600).

[0047] The coaxial illumination source (500) is a coaxial illumination module that can be switched to visible light or infrared light to meet the testing needs of different types of products.

[0048] In this embodiment, the optical inspection device can simultaneously meet the detection requirements of the visible light band and the infrared band; the overall structure is simple, requiring no changes to the chuck or the addition of multiple optical heads, only one set of optical heads is needed; it can simultaneously perform infrared inspection of the back and front sides of the wafer; it can be compatible with different magnifications and can switch magnifications in real time.

[0049] The above description is only a preferred embodiment of the present utility model and does not limit the patent scope of the present utility model. All equivalent structural transformations made under the inventive concept of the present utility model using the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present utility model.

Claims

1. An optical detection device, characterized in that, The optical inspection device includes: an infrared band extended camera (100), an infrared band extended microscope tube (200), an infrared band extended objective lens (300), a clamping plate (400), a coaxial illumination source (500), a rotating wheel (600), and a wafer to be inspected (800). The infrared band extension camera (100) is connected to the infrared band extension microscope tube (200). The rotating wheel (600) is located below the infrared band extension microscope tube (200). The infrared band extension objective lens (300) is located below the rotating wheel (600). The coaxial illumination source (500) is located on one side of the infrared band extension microscope tube (200). The clamping plate (400) is located below the infrared band extension objective lens (300). The wafer to be inspected (800) is located on the clamping plate (400). The coaxial illumination source (500) generates visible light, which is reflected by the beam splitter inside the infrared band extended microscope tube (200), passes through the infrared band extended objective lens (300), and reaches the wafer to be inspected (800). The visible light undergoes specular reflection on the wafer to be inspected (800), passes through the infrared band extended objective lens (300) and the infrared band extended microscope tube (200), and returns to the infrared band extended camera (100) for imaging. The coaxial illumination source (500) generates infrared light. The infrared light is reflected by the beam splitter inside the infrared band extended microscope tube (200), passes through the infrared band extended objective lens (300), and reaches the wafer to be tested (800). Part of the light is specularly reflected on the wafer to be tested (800), passes through the infrared band extended objective lens (300) and the infrared band extended microscope tube (200), and returns to the infrared band extended camera (100). Part of the light passes through the wafer to be tested (800), is reflected on the clamping plate (400), passes through the wafer to be tested (800) again, passes through the infrared band extended objective lens (300) and the infrared band extended microscope tube (200), and returns to the infrared band extended camera (100) for imaging. As the clamp (400) moves, the infrared band extension camera (100) is triggered to take pictures at a set frequency, and the coaxial illumination source (500) is triggered to strobe at the set frequency, so as to simultaneously acquire information on both sides of the wafer (800) to be tested.

2. The optical detection device as described in claim 1, characterized in that, The optical detection device also includes a ring light source (700); The ring light source (700) is a ring light used to provide dark field illumination to detect bump and pit defects in the wafer (800) to be inspected.

3. The optical detection device as described in claim 1, characterized in that, The rotary dial (600) is used to switch between different magnification objectives.

4. The optical detection device as described in claim 1, characterized in that, The clamp (400) is a microporous adsorption type clamp with a silver surface.

5. The optical detection device as described in claim 1, characterized in that, The spectral response range of the infrared band extended camera (100) includes the visible spectrum and the infrared spectrum.

6. The optical detection device as described in claim 1, characterized in that, The transmission bands of the infrared extended microscope tube (200) and the infrared extended objective lens (300) both include the visible light band and the infrared band.

7. The optical detection device as described in any one of claims 1-6, characterized in that, The magnification of the infrared band extension objective (300) can be adjusted by the rotary wheel (600) according to the product testing accuracy requirements. The magnification of the infrared band extension objective (300) includes 2x, 5x or 10x.

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