Patent Application
20220208720
The present application claims the benefit of Korean Patent Application No. 10-2020-0186902 filed in the Korean Intellectual Property Office on Dec. 30, 2020, the entire contents of which are incorporated herein by reference.
The present invention relates to a substrate bonding apparatus and method, and more specifically, to a substrate bonding apparatus and method that is capable of having a simplified configuration and reducing errors generated by misalignments of substrates, while the substrates are being bonded to each other.
With the development of technologies and industries, recently, high-integration for a semiconductor device or substrate (hereinafter referred to as “substrate”) has been increasingly needed. In the case where high-integrated substrates are disposed on a plane surface, connected to each other through wires, and are thus provided as a product, some problems, such as wire length increasing, wire resistance rising, and wiring delay, may occur.
Accordingly, a three-dimensional integration technology that laminates substrates three-dimensionally has been suggested. According to the three-dimensional integration technology, two substrates are bonded to each other, for example, using a bonding apparatus.
In a process of bonding the substrates, further, it is very important to align the upper substrate and the lower substrate with each other. That is, after the upper substrate and the lower substrate are aligned with each other at high precision, they are bonded to each other.
As shown in
According to the conventional substrate bonding method, as shown in
Next, as shown in
That is, if the lower substrate 8 remains in the space between the upper cameras 2 and the lower cameras 4, the alignment key of the upper substrate 6 cannot be recognized by the lower cameras 4, and accordingly, the lower substrate 8 performs the avoidance operation so that it escapes from the space between the upper cameras 2 and the lower cameras 4.
Next, as shown in
However, the conventional substrate bonding method needs the avoidance operation through which the substrate whose alignment key have been recognized escapes from the space between the cameras and the returning operation through which the substrate is returned to the space between the cameras. In the processes of performing the avoidance operation and the returning operation, accordingly, errors may occur so that the substrate is not returned accurately to the coordinate values originally stored. As substrate bonding requires high precision, therefore, such coordinate errors have bad influences on the substrate bonding to undesirably increase a defect rate.
To compensate for the errors generated during the returning operation of the substrate, further, conventional technologies using compensation through a laser interferometer or separate optical meter have been developed, but in the process of bonding the substrates, such compensation methods are added, thereby increasing the time required for substrate bonding to lower efficiency in the substrate bonding.
Besides, the conventional substrate bonding apparatus has the cameras disposed on both the upper portion and the lower portions in an interior of the chamber, so that the apparatus becomes complicated in configuration, exhibits low space utilization in the chamber, and provides hard maintenance.
Accordingly, the present invention has been made in view of the above-mentioned problems occurring in the related art, and it is an object of the present invention to provide a substrate bonding apparatus that is capable of having a simplified configuration and enhancing space utilization in a chamber thereof.
It is another object of the present invention to provide a substrate bonding method that is capable of reducing defects generated by misalignments of substrates, while the substrates are being bonded to each other.
To accomplish the above-mentioned objects, according to one aspect of the present invention, there is provided a substrate bonding apparatus including: a chamber; a first chuck configured inside the chamber to adhere a first substrate; a second chuck configured facingly inside the chamber toward the first chuck to adhere a second substrate; and a camera located above or under the first chuck and the second chuck to recognize first alignment key configured on the first substrate and second alignment key configured on the second substrate.
According to the present invention, the substrate bonding apparatus may further include a first stage disposed inside the chamber and a second stage disposed inside the chamber and movable relatively to the first stage in vertical and horizontal directions, and in this case, the first chuck and the second chuck are mounted on the first stage and the second stage, respectively.
According to the present invention, the camera directly recognizes either the first alignment key or the second alignment key and recognizes the other alignment key by penetrating the first substrate or the second substrate.
According to the present invention, the camera is an infrared camera.
According to the present invention, further, either the first chuck or the second chuck has first through hole and second through hole formed thereon to allow the first alignment key and the second alignment key to be photographed through the camera.
According to the present invention, the substrate bonding apparatus may further include pieces of compensation glass disposed in either the first through hole or the second through hole to adjust focal distances between the first substrate and the second substrate.
According to the present invention, the first through hole is formed at corresponding position to the first alignment key or the second alignment key, and the second through hole is formed so as not to overlap the first substrate or the second substrate.
According to the present invention, the camera directly recognizes either the first alignment key or the second alignment key through the second through hole and recognizes the other alignment key by penetrating first substrate or the second substrate through the first through hole.
According to the present invention, the substrate bonding apparatus may further include a plurality of measuring devices configured on either the first chuck or the second chuck to measure a distance between the first chuck and the second chuck and a plurality of horizontal level adjusting devices configured on the other chuck to keep the distance between the first chuck and the second chuck to a predetermined deviation or under.
To accomplish the above-mentioned objects, according to another aspect of the present invention, there is provided a substrate bonding method including the steps of: directly recognizing either first alignment key of a first substrate adhered to a first chuck or second alignment key of a second substrate adhered to a second chuck; recognizing the other alignment key by penetrating the first substrate or the second substrate; relatively moving the first chuck and the second chuck to each other to align the first alignment key of the first substrate and the second alignment key of the second substrate with each other; and bonding the first substrate and the second substrate to each other.
According to the present invention, between the step of directly recognizing either the first alignment key of the first substrate or the second alignment key of the second substrate and the step of recognizing the other alignment key by penetrating the first substrate or the second substrate, the first chuck or the second chuck sucking the first substrate or the second substrate with the first or second alignment key already recognized at the step of directly recognizing the first or second alignment key does not move.
According to the present invention, the steps of recognizing the first and second alignment key are carried out by recognizing the first and second alignment key by means of through hole formed on either the first chuck or the second chuck.
According to the present invention, the through hole may include first through hole formed at corresponding position to the first alignment key or the second alignment key and second through hole not overlapping the first substrate or the second substrate, the step of directly recognizing either the first alignment key of the first substrate or the second alignment key of the second substrate being carried out by recognizing the alignment key through the second through hole and the step of recognizing the other alignment key by penetrating the first substrate or the second substrate being carried out by recognizing the alignment key through the first through hole.
According to the present invention, the substrate bonding method may further include, between the step of directly recognizing either the first alignment key of the first substrate or the second alignment key of the second substrate and the step of recognizing the other alignment key by penetrating the first substrate or the second substrate, the step of relatively moving the first chuck and the second chuck to each other in a horizontal direction by a distance between the first through hole and the second through hole.
The above and other objects, features and advantages of the present invention will be apparent from the following detailed description of the embodiments of the invention in conjunction with the accompanying drawings, in which:
Hereinafter, an explanation of a configuration of a substrate bonding apparatus 1000 according to the present invention will be given in detail with reference to the attached drawings.
Referring to
The chamber 100 provides a space portion 102 for accommodating the first substrate 40 and the second substrate 20 therein. For example, the chamber 100 includes a chamber body 120 and a chamber lid 110 for sealing an open top of the chamber body 120. The chamber 100 is exemplarily configured like this, but of course, the chamber 100 may be appropriately varied in configuration.
The first chuck 200 and the second chuck 300 are disposed inside the chamber 100 to fixedly adhere the first substrate 40 and the second substrate 20 thereonto. The first chuck 200 and the second chuck 3 may be vacuum chucks, electrostatic chucks, mechanical clamping chucks, and the like, and according to the present invention, vacuum chucks are used as the first chuck 200 and the second chuck 300.
The first chuck 200 is disposed in a lower space of an interior of the chamber 100 to fixedly adhere the first substrate 40 entering the interior of the chamber 100 through a robot arm (not shown) thereonto.
Referring to
Referring back to
Moreover, the second chuck 300 is disposed in an upper space of the interior of the chamber 100. The second chuck 300 is disposed to face the first chuck 200. That is, the second chuck 300 is disposed to face the first chuck 200 and movable relatively to the first chuck 200 in the vertical and horizontal directions. For example, both the first chuck 200 and the second chuck 300 are movable in the vertical and horizontal directions.
In a state where top and underside of the second substrate 20 become reverse to allow a first surface on which the second alignment key 22 is disposed to become the underside thereof, the second substrate 20 enters the interior of the chamber 100. The second chuck 300 fixedly sucks a second surface of the second substrate 20, on which the second alignment key 22 is not disposed, thereonto.
Further, a first stage 220 is disposed inside the chamber 100, and a second stage 400 is disposed inside the chamber 100 and movable relatively to the first stage 220 in vertical and horizontal directions.
For example, the first stage 220 is disposed on a base 122 of the chamber 100, and the first chuck 200 is disposed on the first stage 220.
Further, the second stage 400 is disposed above the first stage 220 and movable relatively to the first stage 220 in the vertical and horizontal directions. The second chuck 300 is connected to the second stage 400.
For example, the second stage 400 includes a driver 424 disposed movably on the base 122 of the chamber 100 and an extension driver 414 extended upward from the driver 424 and connected to the second chuck 300.
The driver 424 is horizontally movable on the base 122 of the chamber 100. Further, the extension driver 414 is disposed movably with respect to the driver 424 to perform precise motions.
That is, the driver 424 moves with relatively low precision, and contrarily, the extension driver 414 moves with relatively high precision to perform alignment for substrate bonding. The first stage 220 and the second stage 400 as mentioned above are exemplarily suggested, but of course, they may be varied appropriately in configuration.
Moreover, the camera 510 is disposed inside the chamber 100 to recognize the first alignment key 42 of the first substrate 40 and the second alignment key 22 of the second substrate 20. The camera 510 is located either above or under the first chuck 200 and the second chuck 300.
According to the present invention, that is, the camera 510 is not located both above and under the first chuck 200 and the second chuck 300, but they are located either above or under the first chuck 200 and the second chuck 300. Referring back to
According to the present invention, the camera 510 is disposed only either above or under the first chuck 200 and the second chuck 300, and accordingly, a configuration in an interior of the chamber 100 can be simplified, thereby enhancing space utilization of the chamber 100 and reducing a volume of the chamber 100.
Besides, the camera 510 directly recognizes either the first alignment key 42 or the second alignment key 22 and recognize the other alignment key by penetrating the first substrate 40 or the second substrate 20.
In specific, the camera 510 is disposed above the first chuck 200 and the second chuck 300, and accordingly, the camera 510 directly recognizes the first alignment key 42 of the first substrate 40 because the first alignment key 42 face them. However, the second substrate 20 has the second alignment key 22 disposed on the underside thereof, and accordingly, the camera 510 cannot directly recognize the second alignment key 22 of the second substrate 20. That is, the camera 510 recognizes the second alignment key 22 by penetrating the second substrate 20.
In the case where the first substrate 40 and the second substrate 20 are made of silicon, if an infrared (IR) camera is used as the camera 510, light emitted from the camera 510 penetrates the second substrate 20 to recognize the second alignment key 22.
The light with a wavelength longer than 0.75 μm emitted from the IR camera can be transmitted through the silicon substrate. For example, the IR camera can emit the light with a wavelength range from 1 to 2 μm, and accordingly, the light can be transmitted through the silicon substrate.
Referring to
Further, the first through hole 310 and the second through hole 320 may be formed on either the first chuck 200 or the second chuck 300. According to the present invention, if the camera 510 is disposed above the first chuck 200 and the second chuck 300, the first through hole 310 and the second through hole 320 is formed on the second chuck 300.
However, if the camera 510 is disposed under the first chuck 200 and the second chuck 300, the first through hole 310 and the second through hole 320 may be formed on the first chuck 200.
In specific, the first through hole 310 is formed at corresponding position to the first alignment key 42 or the second alignment key 22, and the second through hole 320 is not overlapped the first substrate 40 or the second substrate 20. Further, the camera 510 directly recognizes either the first alignment key 42 or the second alignment key 22 through the second through hole 320 and recognizes the other alignment key by penetrating the first substrate 40 or the second substrate 20 through the first through hole 310.
For example, if the second substrate 20 is fixedly adhered to the second chuck 300, the first through hole 310 is formed on the second chuck 300 at the corresponding position to the second alignment key 22 of the second substrate 20.
Further, if the second substrate 20 is fixedly adhered to the second chuck 300, the second through hole 320 is formed on the second chuck 300 in such a manner as to be not overlapped the second substrate 20.
Accordingly, the camera 510 directly recognizes the first alignment key 42 of the first substrate 40 sucked onto the first chuck 200 through the second through hole 320. Further, the camera 510 transmit the light emitted therefrom through the second substrate 20 through the first through hole 310 to recognize the second alignment key 22.
If the first substrate 40 and the second substrate 20 are bonded to each other, moreover, a high degree of precision is needed, and accordingly, high magnification camera is used as the camera 510. In this case, the camera 510 has relatively short focal distances. As the first substrate 40 and the second substrate 20 are spaced apart from each other in a vertical direction, however, it is hard for the camera 510 to recognize both the first alignment key 42 of the first substrate 40 and the second alignment key 22 of the second substrate 20. That is, if the focal distances of the camera 510 is set up to the second substrate 20, it is hard for the camera 510 to recognize the first alignment key 42 of the first substrate 40.
To solve such problems, accordingly, pieces of compensation glass 550 are disposed in either the first through hole 310 or the second through hole 320.
According to the present invention, the pieces of compensation glass 550 are disposed in the second through hole 320 to adjust the focal distances between the first substrate 40 and the second substrate 20. Further, if the pieces of compensation glass 550 are disposed in the first through hole 310, they adjust the focal distances between the first substrate 40 and the second substrate 20, and simultaneously, they adjust the refractive index of the substrate if the camera recognize the alignment key by penetrating the substrate.
Through the pieces of compensation glass 550, according to the present invention, both the first alignment key 42 of the first substrate 40 and the second alignment key 22 of the second substrate 20, which are spaced apart from each other, can be recognized by means of the single camera 510.
The pieces of compensation glass 550 are exchangeably disposed on the corresponding chuck to ensure precise focal distances according to external specification changes, such as magnification changes of the camera 510, changes in shape of the alignment key 22 and 42, changes in thickness of the substrates 20 and 40, and the like, and further, they can be adjustably disposed in position on the chuck.
Even though not shown in the drawings, further, a plurality of measuring devices may be disposed on either the first chuck 200 or the second chuck 300 to measure a distance between the first chuck 200 and the second chuck 300, and a plurality of horizontal level adjusting devices may be disposed on the other chuck to adjust the distance between the first chuck 200 and the second chuck 300 to a predetermined deviation or under.
For example, laser sensors may be used as the measuring devices and formed on either the first chuck 200 or the second chuck 300. If the distance measured by the measuring devices is greater than the predetermined deviation, the distance between the first chuck 200 and the second chuck 300 is constantly maintained by means of the horizontal level adjusting devices. For example, piezoelectric elements may be used as the horizontal level adjusting devices. In this case, the distance between the first chuck 200 and the second chuck 300 can be adjusted precisely to have a deviation within a few nm.
Referring to
Referring first to
Next, either the first alignment key 44 of the first substrate 40 adhered to the first chuck 200 or the second alignment key 22 of the second substrate 20 adhered to the second chuck 300 are directly recognized. Further, the steps of recognizing the alignment key 22 and 42 are carried out by recognizing the alignment key 22 and 42 through first and second through hole 310 and 320 formed on either the first chuck 200 or the second chuck 300.
Hereinafter, an explanation will be given under the assumption that the camera 510 is disposed above the first chuck 200 and the second chuck 300 and the first and second through hole 310 and 320 is formed on the second chuck 300.
For example, as shown in
Next, as shown in
For example, the step of relatively moving the first chuck 200 and the second chuck 300 to each other in a horizontal direction by a distance between the first through hole 310 and the second through hole 320 is carried out between the step of directly recognizing either the first alignment key 44 of the first substrate 40 or the second alignment key 22 of the second substrate 20 and the step of recognizing the other alignment key by penetrating the first substrate 40 or the second substrate 20.
That is, as shown in
In this case, the horizontally moving distance of the second chuck 300 corresponds to the distance between the first through hole 310 and the second through hole 320. After the second chuck 300 moves, accordingly, the first through hole 310 is located under the camera 510 in vertical directions with respect to the camera 510.
Even though not shown, after the second chuck 300 moves horizontally, a step of moving down the second chuck 300 toward the first chuck 200 in a vertical direction is further carried out.
In a state where the first chuck 200 and the second chuck 300 are arranged closest to each other to the maximum, if the alignment is carried out, the moving distances of the substrates in a vertical direction can become short at the step of bonding the substrates as will be discussed later, thereby minimizing substrate misalignment occurring when the substrates move vertically.
Further, as shown in
In this case, between the step S410 of directly recognizing either the first alignment key 44 of the first substrate 40 or the second alignment key 22 of the second substrate 20 and the step S430 of recognizing the other alignment key by penetrating the first substrate 40 or the second substrate 20, the first chuck 200 sucking the first substrate 40 with the first alignment key 42 recognized at the step S410 does not move.
For example, in the case where the second chuck 300 horizontally moves by the distance between the first through hole 310 and the second through hole 320, the first chuck 200 does not move.
According to the present invention, so as to recognize the second alignment key 22 of the second substrate 20 after the first alignment key 42 of the first substrate 40 has been recognized, accordingly, there is no need to move the first substrate 40, so that errors or misalignment occurring when the first substrate 40 is returned to the second substrate 20 can be minimized.
If the first alignment key 42 and the second alignment key 22 are recognized by the camera 510, further, their coordinates can be calculated through a controller (not shown) of the substrate bonding apparatus 1000. After the coordinates of the first alignment key 42 and the second alignment key 22 are calculated, the first chuck 200 and the second chuck 300 move relatively to each other to align the first alignment key 42 of the first substrate 40 and the second alignment key 22 of the second substrate 20 with each other, and next, the second chuck 300 moves down to allow the first substrate 40 and the second substrate 20 to be bonded to each other.
As described above, the substrate bonding apparatus according to the present invention is configured to allow the camera to be disposed either above or under the first chuck and the second chuck, so that the substrate bonding apparatus can be more simplified in configuration than the conventional technologies and enhance the space utilization in the chamber.
In addition, the substrate bonding method according to the present invention is carried out to have no avoidance and returning operations of the substrate, so that the coordinate errors can be prevented from occurring due to the returning operation of the substrate to thus reduce the defects caused by the misalignment of the substrates.
While the present invention has been described with reference to the particular illustrative embodiments, it is not to be restricted by the embodiments but only by the appended claims. It is to be appreciated that those skilled in the art can change or modify the embodiments without departing from the scope and spirit of the present invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2020-0186902 | Dec 2020 | KR | national |
