CN218333691U

CN218333691U - Wafer bonding device

Info

Publication number: CN218333691U
Application number: CN202222763013.7U
Authority: CN
Inventors: 樊树宝; 张昊; 王莎
Original assignee: Beijing U Precision Tech Co Ltd
Current assignee: Beijing U Precision Tech Co Ltd
Priority date: 2022-10-20
Filing date: 2022-10-20
Publication date: 2023-01-17
Anticipated expiration: 2032-10-20

Abstract

The utility model relates to a chip manufacturing technical field especially relates to a wafer bonding device. The utility model aims at providing a can make and go up wafer from inside to outside even deformation, reduce the hollow production of bonding, reduce the wafer bonding device to the influence of alignment precision, specifically include chuck, press device, it is provided with opening, cavity, first air flue to go up the chuck, first air flue one end intercommunication the cavity, first air flue other end intercommunication air supply, the cavity be for set up in the recess of last chuck lower surface, press device is connected with drive arrangement, drive arrangement is suitable for the drive press device moves down and passes the opening and contact go up the wafer, make go up wafer at least part contact time wafer, be provided with seal assembly on the open-ended lateral wall.

Description

Wafer bonding device

Technical Field

The utility model relates to a chip manufacturing technical field especially relates to a wafer bonding device.

Background

At present, a common hybrid bonding technology is developed for the current backside-illuminated CIS chip and 3D memory chip processes, and is an optimal solution for solving the bottleneck problem of interconnection leads. The pre-bonding process is the most critical link of the hybrid bonding technology and determines the quality of the bonding effect.

The prior art pre-bonding process is roughly divided into three steps. Firstly, after an upper wafer and a lower wafer are aligned, the center of an upper wafer chuck is released in vacuum, the peripheral area is kept in vacuum, and the circle center part of the upper wafer is deformed under a certain technical scheme; secondly, the circle center of the upper wafer protrudes to a preset value, namely after the upper wafer is contacted with the lower wafer, the vacuum of the peripheral area of the upper wafer is slowly released until the upper wafer is separated from the chuck and is completely overlapped with the lower wafer through self extension; and finally, the lower chuck rises, so that the wafer pair is further closely attached and the residual gas between the wafers is removed, and air gaps are prevented from appearing on the attaching surface, thereby influencing the pre-bonding effect.

In the whole pre-bonding process, a series of factors such as the wafer gap before pre-bonding, the deformation force of the upper wafer, the vacuum release time of the upper wafer and the like play a crucial role in the pre-bonding process. Among these factors, control of the upper wafer deformation force and deformation mode is particularly important.

In the prior art, a hard top pin is installed at the center of an upper wafer chuck, the top pin moves downwards and extrudes the circle center of the upper wafer to form a wafer center bulge until the center of the upper wafer and a lower wafer are in contact extrusion, and then the wafer is completely attached to the lower wafer gradually by means of the ductility of the wafer. However, the wafer itself has factors causing irregular stress inside the wafer, such as uneven thickness and local warpage, which easily causes irregular and uneven deformation of the upper wafer in the circumferential direction. Such irregular, uneven deformation inevitably seriously affects the alignment accuracy and causes the generation of a bonding void. In addition, the pure rigid contact and extrusion of the top pin to the wafer easily causes damage to the back surface of the wafer, and deteriorates the surface quality of the wafer.

SUMMERY OF THE UTILITY MODEL

The to-be-solved technical problem of the utility model is to provide a wafer bonding device makes the last wafer from inside to outside even deformation, reduces the hollow production of bonding, reduces the influence to the alignment accuracy, improves the bonding quality in advance.

In order to solve the technical problem, the present application provides the following technical solutions:

the utility model discloses wafer bonding device, including last chuck, press device, it is used for adsorbing the wafer to go up the chuck lower surface, it is provided with opening, cavity, first air flue to go up the chuck, first air flue one end intercommunication the cavity, first air flue other end intercommunication air supply, the cavity be for set up in go up the recess of chuck lower surface, press device is connected with drive arrangement, drive arrangement is suitable for the drive press device moves down and passes opening and contact go up the wafer makes go up wafer partial contact wafer down at least, be provided with seal assembly on the open-ended lateral wall.

The utility model discloses wafer bonding device, wherein seal assembly is the gasbag, the second air flue has been seted up on going up the chuck, the second air flue with the gasbag inner chamber is linked together.

The utility model discloses wafer bonding device, wherein the press device lower extreme is provided with the seal cover, the seal cover with the lateral wall of gasbag suits.

The utility model discloses wafer bonding device, wherein the seal cover is made by elastic material.

The utility model discloses wafer bonding device, wherein tip longitudinal section profile has certain camber under the press device.

The utility model discloses wafer bonding device, wherein the opening is located go up the center of chuck.

The utility model discloses wafer bonding device, wherein the cavity is located go up the center of chuck, the cavity is located the below of gasbag, the cavity with the gasbag center aligns.

The utility model discloses wafer bonding device wherein still includes displacement sensor, displacement sensor set up in on the chuck, displacement sensor is located open-ended periphery.

The utility model discloses wafer bonding device wherein still includes force sensor, force sensor set up in the press device top.

Compared with the prior art, the utility model discloses wafer bonding device has following beneficial effect at least:

the utility model discloses wafer bonding device, owing to including last chuck, press device, go up the chuck and be provided with opening, cavity, first air flue, press device can control the protruding deformation at last wafer center part accurately and steadily, and compressed air can get into the cavity through first air flue, acts on last wafer. On one hand, the compressed air has the self-adaptive characteristic, can well adapt to the irregular stress in the upper wafer after the deformation of the center of the upper wafer is finished, and is insensitive to a bonding action point, so that the deformation amount and the deformation rate of the protrusion at the center of the upper wafer can be accurately and stably controlled by controlling the compressed air to form fine adjustment control on the deformation of the upper wafer, and the deformation process of the upper wafer is jointly regulated and controlled by the pressing device and the compressed air; on the other hand, in the bonding process after the upper wafer and the lower wafer are contacted, compressed air can be matched with the desorption effect of the vacuum air passage, so that the upper surface of the wafer subjected to the acting force of the compressed air extends from inside to outside, the surface of the upper wafer is simultaneously subjected to pressure change from the compressed air and adsorption force change from the vacuum air passage, and the upper wafer is ensured to be uniformly deformed from inside to outside by accurately matching compressed air injection process control and vacuum air passage control until the upper wafer and the lower wafer are completely bonded, the generation of bonding cavities is reduced, the influence of alignment accuracy errors is reduced, and the bonding quality is improved.

The wafer bonding apparatus of the present invention will be further described with reference to the accompanying drawings.

Drawings

Fig. 1 is a schematic structural diagram of a wafer bonding apparatus according to the present invention;

fig. 2 is a schematic structural view of a knock pin in the wafer bonding apparatus of the present invention;

fig. 3 is a schematic structural view of an upper chuck in the wafer bonding apparatus of the present invention.

Detailed Description

As shown in fig. 1, fig. 2, fig. 3, the utility model discloses wafer bonding device, including last chuck 1, press device 2, it is provided with vacuum air flue (not shown in the figure) to go up chuck 1, make and go up chuck 1 lower surface and pass through vacuum adsorption and go up wafer 6, it is provided with opening 11 to go up chuck 1, cavity 12, first air flue 13 one end intercommunication cavity 12, first air flue 13 other end intercommunication positive pressure air supply (not shown in the figure), the positive pressure air supply can be compressed air, cavity 12 is the recess that sets up in last chuck 1 lower surface, compressed air gets into cavity 12 through first air flue 13, compressed air can cooperate press device 2 to control brilliant circular rate of change and deformation volume together, compressed air can also cooperate and go up chuck vacuum air flue, it separates with adsorbed last wafer 6 to enable to go up chuck 1, the bonding of wafer 6 and lower wafer 4 is gone up in the completion.

The pressing device 2 is disposed above the upper chuck 1, the pressing device 2 is located corresponding to the opening 11, the pressing device 2 is connected to a driving device (not shown in the figure), the driving device is adapted to drive the pressing device 2 to move downward to pass through the opening 11 and contact the upper wafer 6, so that at least a portion of the upper wafer 6 contacts the lower wafer 4, and the driving device is further adapted to drive the pressing device 2 to move upward to leave the opening 11. The side wall of the opening 11 is provided with a sealing component, and when the pressing device 2 is inserted into the opening 11, the pressing device 2 and the opening 11 can be mutually sealed. The pressing means 2 may be a rod or a pin.

The utility model discloses wafer bonding device during operation, lower wafer 4 rises, stops after the interval of last wafer 6 and lower wafer 4 reaches bonding demand distance, goes up wafer 6, lower wafer 4 and aligns and confirms the back, opens bonding process: under the drive of the driving device, the pressing device 2 passes through the opening 11 to move downwards, the moving displacement value and the force feedback value of the pressing device 2 are recorded after the lower end of the pressing device 2 contacts the back surface of the upper wafer 6, the pressing device 2 continues to move downwards until the upper wafer 6 contacts the lower wafer 4, the upper chuck 1 keeps adsorbing the upper wafer 6 through the vacuum air channel in the process, the pressing device 2 and the opening 11 are sealed mutually, and the first air channel 13 keeps closed. After the upper wafer 6 contacts the lower wafer 4, the first air channel 13 is opened, and compressed air starts to be injected into the cavity 12 through the first air channel 13. The compressed air acts on the upper surface of the upper wafer 6, and the deformation amount of the upper wafer 6 can be finely controlled. In the laminating process after the upper wafer 6 is contacted with the lower wafer 4, the injection process control of compressed air needs to be accurately matched with the control of the vacuum air passages, the change condition of the compressed air pressure is monitored until all the vacuum air passages of the upper chuck 1 are closed, the upper wafer 6 is completely separated from the upper chuck 1, the upper wafer 6 is completely laminated with the lower wafer 4, at the moment, the first air passage 13 is closed, the pressing device 2 is withdrawn, then the lower chuck 5 lifts the wafer pair to ascend until the wafer pair is contacted with the upper chuck 1, the upper chuck 1 and the lower chuck 5 clamp the wafer pair so as to eliminate residual gas at a bonding interface, bubbles at the bonding surface are prevented, and the bonding technological process is finished.

The utility model discloses wafer bonding device, because including last chuck 1, press device 2, go up chuck 1 and be provided with opening 11, cavity 12, first air duct 13, press device 2 can control the protruding deformation at wafer center part accurately steadily, and compressed air can get into cavity 12 through first air duct 13, acts on the wafer. On one hand, the compressed air has a self-adaptive characteristic, can well adapt to the irregular stress in the upper wafer 6 after the center of the upper wafer 6 is deformed, and is insensitive to a bonding action point, so that the deformation amount and the deformation rate of the center bulge of the upper wafer 6 can be accurately and stably controlled by controlling the compressed air to form fine adjustment control on the deformation of the upper wafer 6, and the deformation process of the upper wafer 6 is jointly controlled by the pressing device 2 and the compressed air; on the other hand, in the bonding process after the upper wafer 6 and the lower wafer 4 are contacted, compressed air can cooperate with the desorption action of the vacuum air passage, so that the upper surface of the wafer which is acted by the compressed air extends from inside to outside, the surface of the upper wafer 6 is simultaneously subjected to pressure change from the compressed air and adsorption force change from the vacuum air passage, and the upper wafer 6 is ensured to be uniformly deformed from inside to outside by accurately matching compressed air injection process control and vacuum air passage control until the upper wafer 6 and the lower wafer 4 are completely bonded, thereby reducing the generation of bonding cavities, reducing the influence of alignment accuracy errors and improving the bonding quality.

Optionally, the sealing component is an air bag 14, a second air passage 141 is formed in the upper chuck 1, the second air passage 141 is communicated with an inner cavity of the air bag 14, and the center of the air bag 14 is aligned with the center of the cavity 12. The air bag 14 is inflated through the second air passage 141, and after the inflation is completed, the air bag 14 is expanded and pressed against the pressing device 2, so that the opening 11 is sealed.

Optionally, a sealing sleeve 21 is disposed at the lower end of the pressing device 2, the sealing sleeve 21 is adapted to a side wall of the airbag 14, the sealing sleeve 21 is made of rubber or other elastic materials, the sealing sleeve 21 is used for being pressed against the airbag 14, the sealing sleeve 21 and the pressing device 2 can be formed by bonding through a sealant or other adhesive materials, and the sealing sleeve 21 can also be integrally formed with the pressing device 2. Under the action of the sealing sleeve 21, the pressing device 2 and the air bag 14 are pressed mutually and tightly, and the sealing effect is further improved.

Optionally, the profile of the longitudinal section of the lower end of the pressing device 2 has a certain curvature, for example, the lower end of the pressing device 2 may be a hemisphere, so that when the lower end of the pressing device 2 contacts with a wafer, it is possible to avoid pressing the upper wafer with a sharp edge, eliminate the possibility of damage to the upper wafer due to too large pressing force caused by small local contact area, and reduce the pressing damage to the back of the upper wafer.

Optionally, the opening 11 is located in the center of the upper chuck 1.

Optionally, the cavity 12 is located in the center of the upper chuck 1, below the bladder 14. Because the cavity 12 is located at the center of the upper chuck 1, one end of the first air duct 13 is communicated with the cavity 12, and the compressed air acts on the upper wafer 6 at the cavity 12 at the center of the upper chuck 1, so that the compressed air is input from the right center of the upper wafer 6, and the uniform deformation of the upper wafer 6 from inside to outside is further ensured.

Optionally, the utility model discloses wafer bonding device still includes displacement sensor, and displacement sensor is hollow structure, and displacement sensor sets up in chuck 1 upper shed 11's periphery, passes from displacement sensor when pressing device 2 inserts in the opening 11, and displacement sensor is used for obtaining the removal displacement value of pressing device 2 when pressing device 2 contacts the wafer back, confirms pressing device 2's removal stroke, and then detects the central deformation volume of last wafer.

Optionally, the utility model discloses wafer bonding device still includes force sensor, and force sensor sets up in 2 tops of press device, with 2 rigid contact of press device, force sensor is used for obtaining the pressure value that acts on the wafer when the wafer back is gone up in the 2 contacts of press device, and the pressure value is the important index of wafer center deformation rate or deflection in the control.

The above-mentioned embodiments are only for describing the preferred embodiments of the present invention, and are not intended to limit the scope of the present invention, and various modifications and improvements made by those skilled in the art without departing from the design spirit of the present invention should fall into the protection scope defined by the claims of the present invention.

Claims

1. The utility model provides a wafer bonding device, its characterized in that, includes chuck (1), press device (2), it is used for adsorbing wafer (6) to go up chuck (1) lower surface, it is provided with opening (11), cavity (12), first gas duct (13) to go up chuck (1), first gas duct (13) one end intercommunication cavity (12), first gas duct (13) other end intercommunication air supply, cavity (12) be for set up in the recess of going up chuck (1) lower surface, press device (2) are connected with drive arrangement, drive arrangement is suitable for the drive press device (2) move down and pass opening (11) and contact go up wafer (6), make go up wafer (6) wafer (4) under at least partial contact, be provided with seal assembly on the lateral wall of opening (11).

2. The wafer bonding apparatus according to claim 1, wherein the sealing component is an air bag (14), a second air passage (141) is formed on the upper chuck (1), and the second air passage (141) is communicated with an inner cavity of the air bag (14).

3. Wafer bonding device according to claim 2, characterized in that a sealing sleeve (21) is arranged at the lower end of the pressing device (2), and the sealing sleeve (21) is adapted to the side wall of the air bag (14).

4. Wafer bonding device according to claim 3, characterized in that the sealing sleeve (21) is made of an elastic material.

5. Wafer bonding device according to any of claims 1 to 4, characterized in that the longitudinal cross-sectional profile of the lower end of the pressing device (2) has a curvature.

6. Wafer bonding apparatus according to claim 1, characterized in that the opening (11) is located in the center of the upper chuck (1).

7. Wafer bonding apparatus according to claim 2, characterized in that the cavity (12) is located at the center of the upper chuck (1), the cavity (12) is located below the gas bag (14), and the cavity (12) is aligned with the gas bag (14) center.

8. The wafer bonding apparatus according to claim 1, further comprising a displacement sensor disposed on the upper chuck (1), the displacement sensor being located at a periphery of the opening (11).

9. Wafer bonding apparatus according to claim 1, characterized in that it further comprises a force sensor arranged on top of the pressing device (2).