Bonding alignment system, bonding equipment and bonding method

Abstract

The invention provides a bonding alignment system, bonding equipment and a bonding method. The bonding alignment system comprises a first target which is provided with a first target spot to calibrate a first position of a wafer; the transparent second target is located between the first target and the image acquisition device, and a second target spot is arranged on the transparent second target so as to calibrate a second position of the to-be-bonded piece; the image acquisition device is used for acquiring a first image with the first target spot and a second image with the second target spot through an optical compensation assembly so as to indicate an alignment deviation value between the first position and the second position; and the optical compensation assembly is located between the second target and the image acquisition device and comprises a plurality of optical path areas.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor manufacturing, and in particular to a bonding alignment system, a bonding device, and a bonding method. Background Art

[0002] In the field of semiconductor manufacturing technology, the three-dimensional integration of semiconductor devices can be achieved by using bonding technology. That is, by bonding two or more semiconductor structures with the same or different functions, the performance of the chip can be improved. Here, the bonding process can be divided according to the bonding object, including wafer to wafer (W2W) bonding, chip to wafer bonding (D2W) and chip to chip bonding (Die to Die, D2D).

[0003] For the alignment step of the chip-to-wafer bonding process, the optical microscope system needs to image the targets of the chip and the wafer to calculate the alignment deviation between the two. In the prior art, alignment is performed by designing a glass target on the chip carrier head. The glass target is located on the side of the same plane of the chip. After the positions of the glass target and the chip target are calibrated, the glass target can be calibrated with the target facing the wafer. However, since the two targets have a certain vertical distance, the depth of field of the microscope objective lens cannot be covered, and the distance will vary depending on the thickness of the chip. When adapting different chips for bonding, a displacement microscope is required to image the glass target and the wafer target. Therefore, the repeatability and precision errors caused by the mechanical displacement will affect the bonding and accuracy of the chip and wafer.

[0004] In order to overcome the above-mentioned defects in the prior art, the present invention provides a bonding alignment technology, which utilizes a simplified device structure to quickly calibrate the alignment deviation, thereby improving the efficiency of bonding alignment. Summary of the invention

[0005] A brief summary of one or more aspects is given below to provide a basic understanding of these aspects. This summary is not an exhaustive overview of all conceived aspects, and is neither intended to identify the key or decisive elements of all aspects nor to define the scope of any or all aspects. Its only purpose is to give some concepts of one or more aspects in a simplified form as a prelude to a more detailed description that will be given later.

[0006] In order to overcome the above-mentioned defects in the prior art, the present invention provides a bonding alignment system, a bonding device, and a bonding method, which utilize a simplified device structure to quickly calibrate the alignment deviation, thereby improving the efficiency of bonding alignment.

[0007] Specifically, the bonding alignment system provided according to the first aspect of the present invention includes: a first target, on which a first target point is provided to calibrate a first position of a wafer; a transparent second target, located between the first target and an image acquisition device, on which a second target point is provided to calibrate a second position of a component to be bonded; the image acquisition device is used to acquire a first image with the first target point and a second image with the second target point via an optical compensation component to indicate an alignment deviation amount between the first position and the second position; and the optical compensation component is located between the second target and the image acquisition device and includes a plurality of optical path areas, wherein the optical compensation component moves its first optical path area between the image acquisition device and the first target so that the image acquisition device can focus on the first target via the first optical path area, and the optical compensation component also moves its second optical path area between the image acquisition device and the second target so that the image acquisition device can focus on the second target via the second optical path area.

[0008] Furthermore, in some embodiments of the present invention, the plurality of optical path areas are arranged on a turntable, and the optical compensation component switches the first optical path area and the second optical path area by rotating the turntable.

[0009] Furthermore, in some embodiments of the present invention, the bonding alignment system also includes: a microscope objective lens, wherein the second optical path area is an empty area, the image acquisition device focuses on the second target via the microscope objective lens, and an optical path plate is provided in the first optical path area to compensate for the optical path difference between the first target and the second target, so that the image acquisition device can focus on the first target via the microscope objective lens, the optical path plate and the second target.

[0010] Furthermore, in some embodiments of the present invention, the optical path plate is made of flat glass, and the relationship between its refractive index and thickness and the optical path difference is expressed as: l=dd / n, wherein l is the optical path difference, n is the refractive index of the optical path plate, and d is the thickness of the optical path plate.

[0011] Furthermore, in some embodiments of the present invention, the bonding alignment system is adapted to a variety of parts to be bonded with different thicknesses, and the turntable is provided with a plurality of first optical path areas with corresponding first optical paths.

[0012] Furthermore, in some embodiments of the present invention, the second target point and the first surface of the part to be bonded close to the image acquisition device both maintain a second optical path that adapts to the second optical path area with the image acquisition device, and the first target point adapts to the position of the part to be bonded away from the second surface of the image acquisition device while maintaining a corresponding first optical path with the image acquisition device, and the optical compensation component is configured to: according to the first optical path, move the corresponding first optical path area to between the image acquisition device and the first target, so that the image acquisition device can focus on the first target via the first optical path area.

[0013] Furthermore, in some embodiments of the present invention, the thickness of the part to be bonded is between 40 microns and 600 microns, and the corresponding optical path plates in the first optical path zone are divided into multiple groups according to the refractive index, wherein each group of the optical path plates has a different refractive index, and each group of the optical path plates has the same refractive index and different thicknesses.

[0014] Furthermore, in some embodiments of the present invention, a plurality of first target points are provided on the first target, a plurality of corresponding second target points are provided on the second target, and the image acquisition device acquires a first image with a plurality of first target points and a second image with a plurality of corresponding second target points via the optical compensation component to improve the detection accuracy of the alignment deviation of the first position and the second position.

[0015] In addition, the bonding equipment provided according to the second aspect of the present invention includes: a bonding alignment system as described in any one of the first aspect of the present invention, used to detect the alignment deviation between the first position of the wafer to be bonded and the second position of the part to be bonded; a first bonding head, on which a first target of the bonding alignment system is provided, for adsorbing the wafer; and a second bonding head, on which a second target of the bonding alignment system is provided, for adsorbing the part to be bonded, and cooperating with the first bonding head to compensate for the alignment deviation, so as to bond the first position of the wafer to the second position of the part to be bonded.

[0016] In addition, the bonding method provided according to the third aspect of the present invention includes the following steps: adsorbing the wafer to be bonded via the first bonding head of the bonding device as described in the second aspect of the present invention, and adsorbing the part to be bonded via its second bonding head; moving the first optical path area of ​​the optical compensation component of the bonding alignment system of the bonding device to between the image acquisition device and the first target of the first bonding head, so as to control the image acquisition device to focus on the first target via the first optical path area, and to acquire a first image with its first target point; moving the second optical path area of ​​the optical compensation component between the image acquisition device and the second target of the second bonding head, so as to control the image acquisition device to focus on the second target via the second optical path area, and to acquire a second image with its second target point; determining the alignment deviation between the first position and the second position according to the position difference between the first target point and the second target point in the corresponding images; and compensating the alignment deviation via the first bonding head and / or the second bonding head, and bonding the first position of the wafer to the second position of the part to be bonded. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The above features and advantages of the present invention can be better understood after reading the detailed description of the embodiments of the present disclosure in conjunction with the following drawings. In the drawings, the components are not necessarily drawn to scale, and components with similar related properties or features may have the same or similar reference numerals.

[0018] Figure 1 A schematic structural diagram of a bonding alignment system provided according to some embodiments of the present invention is shown.

[0019] Figure 2 A schematic diagram of the optical path principle of optical path sheet imaging according to some embodiments of the present invention is shown.

[0020] Figure 3 A light path principle diagram of optical path sheets with different thicknesses provided according to some embodiments of the present invention is shown.

[0021] Figure 4 A schematic flow chart of a bonding method provided according to some embodiments of the present invention is shown.

[0022] Reference numerals:

[0023] 10 First Target

[0024] 20 Second Target

[0025] 201 Parts to be bonded

[0026] 30 Microscope objective

[0027] 40 optical path film

[0028] 50 Turntable DETAILED DESCRIPTION

[0029] The following specific embodiments illustrate the implementation of the present invention, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. Although the description of the present invention will be introduced in conjunction with the preferred embodiment, this does not mean that the features of this invention are limited to this implementation. On the contrary, the purpose of introducing the invention in conjunction with the implementation is to cover other options or modifications that may be extended based on the claims of the present invention. In order to provide a deep understanding of the present invention, the following description will include many specific details. The present invention can also be implemented without using these details. In addition, in order to avoid confusion or blurring the focus of the present invention, some specific details will be omitted in the description.

[0030] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0031] In addition, the terms "upper", "lower", "left", "right", "top", "bottom", "horizontal" and "vertical" used in the following description should be understood as the directions shown in the paragraph and the related drawings. Such relative terms are only used for the convenience of description and do not mean that the device described therein must be manufactured or operated in a specific direction, and therefore should not be understood as limiting the present invention.

[0032] It is understood that although the terms "first", "second", "third", etc. may be used herein to describe various components, regions, layers and / or parts, these components, regions, layers and / or parts should not be limited by these terms, and these terms are only used to distinguish different components, regions, layers and / or parts. Therefore, the first component, region, layer and / or part discussed below may be referred to as a second component, region, layer and / or part without departing from some embodiments of the present invention.

[0033] As mentioned above, in the field of semiconductor manufacturing technology, the three-dimensional integration of semiconductor devices can be achieved by using bonding technology. That is, by bonding two or more semiconductor structures with the same or different functions, the performance of the chip can be improved. Here, the bonding process can be divided according to the bonding object, including wafer to wafer (W2W) bonding, chip to wafer bonding (D2W) and chip to chip bonding (D2W).

[0034] For the alignment step of the chip-to-wafer bonding process, the optical microscope system needs to image the targets of the chip and the wafer to calculate the alignment deviation between the two. In the prior art, alignment is performed by designing a glass target on the chip carrier head. The glass target is located on the side of the same plane of the chip. After the positions of the glass target and the chip target are calibrated, the glass target can be calibrated with the target facing the wafer. However, since the two targets have a certain vertical distance, the depth of field of the microscope objective lens cannot be covered, and the distance will vary depending on the thickness of the chip. When adapting different chips for bonding, a displacement microscope is required to image the glass target and the wafer target. Therefore, the repeatability and precision errors caused by the mechanical displacement will affect the bonding and accuracy of the chip and wafer.

[0035] In order to overcome the above-mentioned defects in the prior art, the present invention provides a bonding alignment system, a bonding device, and a bonding method, which utilize a simplified device structure to quickly calibrate the alignment deviation, thereby improving the efficiency of bonding alignment.

[0036] In some non-limiting embodiments, the bonding alignment system provided in the first aspect of the present invention can be configured on the bonding device provided in the second aspect of the present invention, and the bonding method provided in the third aspect of the present invention can be implemented based on the bonding device provided in the second aspect of the present invention.

[0037] Specifically, the bonding device provided according to the second aspect of the present invention includes a bonding alignment system, a first bonding head and a second bonding head.

[0038] The bonding alignment system is used to detect the alignment deviation between the first position of the wafer to be bonded and the second position of the part to be bonded. The first bonding head is provided with a first target of the bonding alignment system for adsorbing the wafer. The second bonding head is provided with a second target of the bonding alignment system for adsorbing the part to be bonded and cooperating with the first bonding head to compensate for the alignment deviation so as to bond the first position of the wafer to the second position of the part to be bonded.

[0039] Please refer to Figure 1 , Figure 1 A schematic structural diagram of a bonding alignment system provided according to some embodiments of the present invention is shown.

[0040] like Figure 1 As shown, the bonding alignment system includes a first target 10, a transparent second target 20 (eg, glass material), an image acquisition device and an optical compensation component.

[0041] The first target 10 is provided with a first target point to calibrate the first position of the wafer. The transparent second target 20 is located between the first target 10 and the image acquisition device, and is provided with a second target point to calibrate the second position of the to-be-bonded component 201. The image acquisition device is used to acquire a first image with the first target point and a second image with the second target point via an optical compensation component to indicate the alignment deviation between the first position and the second position. The optical compensation component is located between the second target 20 and the image acquisition device, and includes a plurality of optical path regions. The optical compensation component moves its first optical path region between the image acquisition device and the first target 10 so that the image acquisition device can focus on the first target 10 via the first optical path region, and the optical compensation component also moves its second optical path region between the image acquisition device and the second target 20 so that the image acquisition device can focus on the second target 20 via the second optical path region.

[0042] In some embodiments, a plurality of optical path zones are disposed on a turntable 50 , and the optical compensation component switches between the first optical path zone and the second optical path zone by rotating the turntable 50 .

[0043] In some embodiments, the bonding alignment system further includes a microscope objective lens 30. The second optical path region is an empty region, and the image acquisition device focuses on the second target point via the microscope objective lens 30. An optical path sheet 40 is provided in the first optical path region to compensate for the optical path difference between the first target 10 and the second target 20, so that the image acquisition device focuses on the first target point via the microscope objective lens 30, the optical path sheet 40 and the second target 20.

[0044] Please refer to Figure 2-3 , Figure 2 A schematic diagram of the optical path principle of optical path sheet imaging according to some embodiments of the present invention is shown. Figure 3 A light path principle diagram of optical path sheets with different thicknesses provided according to some embodiments of the present invention is shown.

[0045] like Figure 2 As shown, the optical path sheet 40 is made of flat glass to avoid the introduction of optical errors such as spherical aberration, chromatic aberration, and coma by the curvature lens. The relationship between the refractive index and thickness of the flat glass and the optical path difference is expressed as:

[0046] l=dd / n,

[0047] Wherein, l is the optical path difference, n is the refractive index of the optical path plate 40 , and d is the thickness of the optical path plate 40 .

[0048] like Figure 3As shown, the bonding alignment system is adapted to a variety of to-be-bonded parts 201 with different thicknesses, and a plurality of first optical path areas with corresponding first optical paths are provided on the turntable 50 .

[0049] The second target point and the component to be bonded 201 are close to the first surface of the image acquisition device, and both maintain a second optical path that adapts to the second optical path area with the image acquisition device. The first target point adapts to the position of the component to be bonded 201 away from the second surface of the image acquisition device, and maintains a corresponding first optical path with the image acquisition device. The optical compensation component is configured to: according to the first optical path, move the corresponding first optical path area to between the image acquisition device and the first target 10, so that the image acquisition device can focus on the first target 10 via the first optical path area.

[0050] In some embodiments, the thickness of the bonded component 201 is between 40 microns and 600 microns, and the optical path sheets 40 corresponding to the first optical path zone are divided into multiple groups according to the refractive index. Each group of optical path sheets 40 has a different refractive index, and each group of optical path sheets 40 has the same refractive index and different thicknesses to accommodate a large thickness range. Specifically, this grouping method can prevent an overly thick optical path sheet 40 from absorbing too much light energy and affecting the imaging quality, and can balance the weight difference of each position of the turntable 50 to avoid alignment errors caused by the tilt of the turntable 50.

[0051] In some embodiments, the thickness change of the bonded component 201 will correspondingly cause the optical path difference of the focus drift of the microscope objective lens 30. For example, for the bonded component 201 with a first thickness t1 (for example: 40um), an optical path sheet 40 with a first refractive index of n1 (for example: 1.52) and a first thickness of d1 (for example: 117um) can be used. For a chip with a second thickness t2 (for example: 600um), an optical path sheet 40 with a second refractive index of n2 (for example: 1.51) and a second thickness of d2 (for example: 1776um) can be used.

[0052] In some embodiments, a plurality of first target points are disposed on the first target 10, and a plurality of corresponding second target points are disposed on the second target 20. The image acquisition device acquires a first image with the plurality of first target points and a second image with the plurality of corresponding second target points via an optical compensation component to improve the detection accuracy of the alignment deviation between the first position and the second position.

[0053] The working principle of the above-mentioned bonding alignment system and bonding equipment will be described below in conjunction with some embodiments of the bonding method. Those skilled in the art will understand that these embodiments of the bonding method are only some non-restrictive implementation methods provided by the present invention, which are intended to clearly demonstrate the main concept of the present invention and provide some specific solutions that are convenient for the public to implement, but are not used to limit all functions or all working modes of the bonding alignment system and bonding equipment. Similarly, the bonding alignment system and bonding equipment system are also only some non-restrictive implementation methods provided by the present invention, and do not constitute a limitation on the execution subject or execution order of each step in these bonding methods.

[0054] Please refer to Figure 4 , Figure 4 A schematic flow chart of a bonding method provided according to some embodiments of the present invention is shown.

[0055] like Figure 4 As shown, the bonding method firstly absorbs the wafer to be bonded via the first bonding head of the bonding device, and absorbs the object to be bonded 201 via the second bonding head thereof.

[0056] Move the first optical path area of ​​the optical compensation component of the bonding alignment system of the bonding device to between the image acquisition device and the first target 10 of the first bonding head, so as to control the image acquisition device to focus on the first target 10 via the first optical path area and acquire a first image with its first target point;

[0057] Move the second optical path area of ​​the optical compensation component to between the image acquisition device and the second target 20 of the second bonding head, so as to control the image acquisition device to focus on the second target 20 via the second optical path area and acquire a second image with its second target point;

[0058] Determining an alignment deviation between the first position and the second position according to a position difference between the first target point and the second target point in the corresponding image; and

[0059] The alignment deviation is compensated by the first bonding head and / or the second bonding head, and the first position of the wafer is bonded to the second position of the object to be bonded 201 .

[0060] In summary, the bonding alignment system, bonding equipment, and bonding method provided by the present invention can utilize a simplified device structure to quickly calibrate the alignment deviation, thereby improving the efficiency of bonding alignment.

[0061] Although the above methods are illustrated and described as a series of actions for simplicity of explanation, it should be understood and appreciated that these methods are not limited by the order of the actions, because according to one or more embodiments, some actions may occur in a different order and / or concurrently with other actions from those illustrated and described herein or not illustrated and described herein but understandable to those skilled in the art.

[0062] The previous description of the disclosure is provided to enable any person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be apparent to those skilled in the art, and the general principles defined herein may be applied to other variations without departing from the spirit or scope of the disclosure. Thus, the disclosure is not intended to be limited to the examples and designs described herein, but should be granted the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A bonding alignment system, characterized in that: include: A first target having a first target point thereon for calibrating a first position of a wafer; A transparent second target, located between the first target and the image acquisition device, and having a second target point thereon for marking a second position of the component to be bonded; The image acquisition device is used to acquire a first image with the first target point and a second image with the second target point via an optical compensation component to indicate an amount of alignment deviation between the first position and the second position; as well as The optical compensation component is located between the second target and the image acquisition device, and includes a plurality of optical path areas, wherein the optical compensation component moves its first optical path area between the image acquisition device and the first target so that the image acquisition device can focus on the first target via the first optical path area, and the optical compensation component also moves its second optical path area between the image acquisition device and the second target so that the image acquisition device can focus on the second target via the second optical path area.

2. The bonding alignment system according to claim 1, wherein: The plurality of optical path areas are arranged on a rotating disk, and the optical compensation component switches the first optical path area and the second optical path area by rotating the rotating disk.

3. The bonding alignment system according to claim 2, wherein: Also includes: A microscope objective lens, wherein the second optical path area is an empty area, the image acquisition device focuses on the second target through the microscope objective lens, and an optical path sheet for compensating the optical path difference between the first target and the second target is provided in the first optical path area, so that the image acquisition device focuses on the first target through the microscope objective lens, the optical path sheet and the second target.

4. The bonding alignment system according to claim 3, wherein: The optical path sheet is made of flat glass, and the relationship between its refractive index and thickness and the optical path difference is expressed as: l=dd / n, Wherein, l is the optical path difference, n is the refractive index of the optical path plate, and d is the thickness of the optical path plate.

5. The bonding alignment system according to claim 4, wherein: The bonding alignment system is adapted to a variety of parts to be bonded with different thicknesses, and the turntable is provided with a plurality of first optical path areas with corresponding first optical paths.

6. The bonding alignment system according to claim 5, characterized in that The second target point and the part to be bonded are close to the first surface of the image acquisition device, and both maintain a second optical path adapted to the second optical path area with the image acquisition device. The first target point adapts to the position of the part to be bonded away from the second surface of the image acquisition device, and maintains a corresponding first optical path with the image acquisition device. The optical compensation component is configured as follows: According to the first optical path, the corresponding first optical path area is moved between the image acquisition device and the first target, so that the image acquisition device focuses on the first target via the first optical path area.

7. The bonding alignment system according to claim 5, wherein: The thickness of the component to be bonded is between 40 microns and 600 microns, and the corresponding optical path plates in the first optical path zone are divided into multiple groups according to the refractive index, wherein each group of optical path plates has a different refractive index, and each group of optical path plates has the same refractive index and different thicknesses.

8. The bonding alignment system according to claim 1, wherein: The first target is provided with a plurality of first target points, and the second target is provided with a plurality of corresponding second target points. The image acquisition device acquires a first image with a plurality of first target points and a second image with a plurality of corresponding second target points via the optical compensation component to improve the detection accuracy of the alignment deviation of the first position and the second position.

9. A bonding device, characterized in that: include: The bonding alignment system according to any one of claims 1 to 8, used for detecting an alignment deviation between a first position of a wafer to be bonded and a second position of a component to be bonded; A first bonding head, on which a first target of the bonding alignment system is disposed, for adsorbing a wafer; as well as The second bonding head is provided with a second target of the bonding alignment system for adsorbing the part to be bonded and cooperating with the first bonding head to compensate for the alignment deviation so as to bond the first position of the wafer to the second position of the part to be bonded.

10. A bonding method, characterized in that: The following steps are involved: Adsorbing the wafer to be bonded via the first bonding head of the bonding device as claimed in claim 9, and adsorbing the component to be bonded via the second bonding head thereof; Moving a first optical path region of an optical compensation component of a bonding alignment system of the bonding device to between an image acquisition device and a first target of the first bonding head, so as to control the image acquisition device to focus on the first target via the first optical path region and to acquire a first image with a first target point thereof; Moving the second optical path area of ​​the optical compensation component to between the image acquisition device and the second target of the second bonding head, so as to control the image acquisition device to focus on the second target through the second optical path area and acquire a second image with its second target point; Determining an alignment deviation between the first position and the second position according to a position difference between the first target point and the second target point in the corresponding image; as well as The alignment deviation is compensated via the first bonding head and / or the second bonding head, and a first position of the wafer is bonded to a second position of the object to be bonded.

Images