Wafer multi-chip degas system and control method thereof

Abstract

The present invention proposes a wafer multi-wafer degas system and a control method thereof, which belongs to the field of semiconductor manufacturing technology. The wafer multi-wafer degas system includes: an atmospheric degas device, a vacuum and atmosphere transfer mechanism connected to the atmospheric degas device, and a vacuum degas device connected to the vacuum and atmosphere transfer mechanism. The vacuum degas device is also connected to a process platform. In the present invention, the degas treatment of the wafer is carried out in the atmosphere most of the time, so most of the impurities can be removed in the atmospheric environment, reducing the pollution in the process platform. The atmospheric degas device uses a movable plate that can be raised and lowered to move the wafer inlet and outlet, and transfers the wafer through a movable manipulator in the atmospheric state, avoiding the movement of the wafer storage mechanism, saving the cavity space, and increasing the actual number of stored wafers. The air curtain design of the wafer inlet and outlet can not only remove the dust on the wafer surface, but also prevent external dust from entering the cavity.

Description

Technical Field

[0001] The present invention belongs to the technical field of semiconductor manufacturing, and in particular relates to a multi-wafer degas system and a control method thereof. Background Art

[0002] Wafer refers to the silicon wafer used to make silicon semiconductor circuits, and its original material is silicon. High-purity polycrystalline silicon is dissolved and doped with silicon crystal seeds, and then slowly pulled out to form cylindrical single crystal silicon. After grinding, polishing, and slicing, the silicon crystal rod forms a silicon wafer, that is, a wafer. In the subsequent processing of the wafer, oxidation-photolithography-etching-thin film deposition-interconnection-testing-packaging and other processing processes are required. In these processes, it is usually necessary to remove impurities and pollutants from the surface of the wafer, that is, degas treatment.

[0003] In the past, degas treatment was performed under vacuum conditions, and vacuum degassing would cause the vacuum process platform to be contaminated. When there are contaminants in the vacuum process platform, the contaminants will fall on the surface of the wafer during subsequent processes such as coating, thereby reducing the quality of the process. Summary of the invention

[0004] To solve the above problems, the present invention proposes a multi-wafer degas system and a control method thereof, adds an atmospheric degas device before the vacuum degas device to perform most of the degas processing, and builds a transfer mechanism between the two devices.

[0005] To achieve the above object, the technical solution of the present invention is as follows:

[0006] A multi-wafer degas system comprises: an atmospheric degas device, a vacuum and atmosphere transfer mechanism connected to the atmospheric degas device, a vacuum degas device connected to the vacuum and atmosphere transfer mechanism, wherein the vacuum degas device is also connected to a process platform; the vacuum degas device comprises a cavity and a driving mechanism, a wafer inlet and outlet are arranged on the cavity, a wafer storage mechanism is arranged in the cavity, and the driving mechanism drives the wafer storage mechanism to move up and down; the atmospheric degas device comprises a cavity and a driving mechanism, a wafer storage mechanism is arranged in the cavity, a movable door plate is arranged on the wafer inlet and outlet side of the cavity, a wafer inlet and outlet are arranged on the movable door plate, and the driving mechanism drives the movable door plate to move up and down, and a plurality of air outlets are distributed on the edges of the wafer inlet and outlet, and the air outlets are connected to the air inlet pipe.

[0007] Furthermore, the outlet direction of the gas outlet is perpendicular to the wafer in and out direction.

[0008] Furthermore, both ends of the wafer inlet and outlet in the atmospheric degas device are connected to sliders through connectors, and slide rails are provided on both sides of the cavity. The slider is arranged in the slide rails and moves along the slide rails.

[0009] Furthermore, the film storage mechanism includes a plurality of support blocks arranged in parallel.

[0010] Furthermore, the edge of the support block of the film storage mechanism of the atmospheric degas device has a slope.

[0011] Furthermore, folded edges are provided on both sides of the movable door panel.

[0012] Furthermore, the height of the folded edge protruding from the cavity surface is greater than the thickness of the movable door panel.

[0013] The present invention also provides a control method for a wafer multi-chip degas system, which is implemented based on the wafer multi-chip degas system and includes the following steps:

[0014] Step 1: Transfer multiple wafers from the wafer inlet and outlet to the atmospheric degas equipment chamber. The initial position of the wafer inlet and outlet is aligned with the bottom support block of the wafer storage mechanism. After the robot places a wafer, the electric cylinder controls the moving plate to rise. Then the robot places another wafer, and the electric cylinder controls the moving plate to rise again... until the wafer storage mechanism is full of wafers. The distance the moving plate rises each time is the distance between adjacent support blocks.

[0015] Step 2, heating the wafer on the wafer storage mechanism to remove impurities, evacuating the inside of the chamber to remove the impurities removed by heating, and performing degas treatment;

[0016] Step 3, after the processing in step 2 is completed, the processed wafer is transferred to a vacuum and atmosphere transfer mechanism;

[0017] Step 4, closing the connection between the vacuum degas equipment and the process platform, opening the connection between the vacuum degas equipment and the vacuum and atmosphere transfer mechanism, the vacuum and atmosphere transfer mechanism has been evacuated, and transferring the multiple wafers in the vacuum and atmosphere transfer mechanism to the vacuum degas equipment cavity;

[0018] Step 5: vacuum degas equipment is used to evacuate the wafer for degas treatment, a heating lamp heats the wafer, and the removed impurities are pumped away by a pump;

[0019] Step 6: After the vacuum degas treatment is completed, open the connection between the vacuum degas equipment and the process platform, transport the wafer to the process platform for subsequent processing, and then close the connection between the vacuum degas equipment and the process platform.

[0020] Furthermore, the atmospheric degas processing time is longer than the vacuum degas processing time.

[0021] Furthermore, in step 4, the process of transferring multiple wafers in the vacuum and atmosphere transfer mechanism to the chamber of the vacuum degas equipment includes: the initial positions of the wafer inlet and outlet are aligned with the top support block of the wafer storage mechanism, and after a wafer is transported to the wafer storage mechanism, the electric cylinder controls the wafer storage mechanism to rise, and the distance of each rise is the distance between adjacent wafer support plates. Each rise transports a wafer to the wafer storage mechanism until the wafer storage mechanism is full of wafers.

[0022] The beneficial effects of the present invention are:

[0023] In the present invention, the degas treatment of the wafer is carried out in the atmosphere most of the time, so most of the impurities can be removed in the atmosphere, thereby reducing the pollution in the process platform. The atmospheric degas equipment uses a liftable moving plate to move the wafer inlet and outlet, and transfers the wafer through a liftable manipulator in the atmospheric state, avoiding the movement of the wafer storage mechanism, saving cavity space, and increasing the actual number of stored wafers. The air curtain design of the wafer inlet and outlet can not only remove dust on the wafer surface, but also prevent external dust from entering the cavity. The present invention can perform degas treatment on multiple wafers at the same time, greatly improving the efficiency of the process without increasing the floor space. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A schematic diagram of the connection of components in the wafer multi-wafer degas system provided by the present invention;

[0025] Figure 2 This is a schematic diagram of the structure of the vacuum degas equipment;

[0026] Figure 3 This is a partially cutaway schematic diagram of a vacuum degas device;

[0027] Figure 4 This is a schematic diagram of the connection between the memory chip mechanism and the drive mechanism of the vacuum degas device;

[0028] Figure 5 This is a schematic diagram of the atmospheric degas equipment structure;

[0029] Figure 6 It is a partially cutaway schematic diagram of the atmospheric degas equipment;

[0030] Figure 7 Schematic diagram of the connection between the moving door panel and the driving mechanism of the atmospheric degas equipment.

[0031] Description of reference numerals:

[0032] 1-degas chamber, 2-driving mechanism, 3-pump, 4-inlet and outlet, 5-heating lamp, 6-temperature sensor, 7-film storage mechanism, 8-electric cylinder, 9-guide rod, 10-support rod, 11-slider, 12-sensing sheet, 13-position sensor, 14-support block, 15-movable door panel, 16-connecting piece, 17-second slider, 18-inlet pipe, 19-outlet, 20-track, 21-folding edge, 22-inclined surface, 23-plane, 24-manual valve. DETAILED DESCRIPTION

[0033] The technical solution provided by the present invention will be described in detail below in conjunction with specific embodiments. It should be understood that the following specific implementation methods are only used to illustrate the present invention and are not used to limit the scope of the present invention.

[0034] like Figure 1 As shown, the multi-wafer degas system provided by the present invention includes an atmospheric degas device, a vacuum degas device, and a vacuum and atmospheric transfer mechanism connected between the first two, and the vacuum degas device is connected to the process platform.

[0035] Since the vacuum degas equipment adopts a conventional structure, the main structure is only roughly described in the present invention and is not described in detail. Figure 2-Figure 4 As shown, the vacuum degas equipment includes a degas chamber 1, a driving mechanism 2 and a pump 3. The degas chamber is provided with an inlet and outlet 4 for wafers to enter and exit, and a heating lamp 5, a temperature sensor 6 and a wafer storage mechanism 7 are provided therein. The wafer storage mechanism is a shelf structure for accommodating multiple wafers. The driving mechanism 2 is used to control the rise of the wafer storage mechanism. The driving mechanism 2 includes a series of structures such as an electric cylinder 8, a guide rod 9, a support rod 10, a slider 11, a sensor sheet 12, and a position sensor 13. The electric cylinder 8 controls the wafer storage mechanism to rise. The distance of each rise is the distance between adjacent support blocks 14 for storing wafers in the wafer storage mechanism. Each time it rises, a wafer is transported to the wafer storage mechanism. After multiple rises, the wafer storage mechanism is filled with wafers. The heating lamp heats the wafer, and the pump removes the impurities.

[0036] The atmospheric degas equipment structure provided in the present invention is as follows Figure 5-Figure 7As shown, most of the structures are the same as those of the vacuum degas equipment, except that: a movable door plate 15 is provided on one side of the wafer inlet and outlet of the atmospheric degas equipment cavity, the inlet and outlet 4 is fixed on the movable door plate 15, and a through hole corresponding to the through hole on the inlet and outlet is also provided on the movable door plate for the wafer to enter and exit. The present invention is designed with an air curtain at the air inlet, the inlet and outlet are connected to the air inlet pipe 18, and the edges of the through holes on the inlet and outlet are distributed with air outlets 19, the air outlets 19 are connected to the air inlet pipe 18, and the air outlet direction is perpendicular to the wafer inlet and outlet direction. The gas blown out of multiple air outlets 19 forms an air curtain to purge the incoming wafers, remove the dust on their surfaces, and prevent external dust from entering the cavity. More specifically, the two ends of the inlet and outlet 4 are respectively connected to the second slider 17 through the connecting piece 16, and the two sides of the cavity are provided with tracks 20 corresponding to the slider spacing, and the second slider 17 moves along the track 20. Folding edges 21 higher than the thickness of the moving door plate are also provided on both sides of the moving door plate, which can effectively prevent metal chips generated by the friction between the second slider 17 and the track 20 from entering the cavity. The wafer storage mechanism in the chamber of the atmospheric degas equipment is fixed in position, and the driving mechanism 2 drives the movable door plate to move. The movement method is similar to the aforementioned vacuum degas equipment. The electric cylinder 8 controls the movable door plate to rise. The distance of each rise is the distance between adjacent support blocks for storing wafers in the wafer storage mechanism, so that the inlet and outlet can always correspond to a group of support blocks. The support block in the present invention has also been improved. The edge of the support block in contact with the wafer has a bevel 22. When the manipulator places the wafer on the support block, the wafer slides to the edge plane 23 of the support block under the action of the bevel 22. The bevel plays a positioning and guiding role. The manipulator used in the atmospheric degas equipment can be lifted and moved to place wafers at different heights, and the wafer storage mechanism does not need to move. The cavity does not need to reserve space for the movement of the wafer storage mechanism, so there is no need to expand the volume of the cavity, or the support blocks of the wafer storage mechanism can be increased to accommodate more wafers.

[0037] The vacuum and atmosphere transfer mechanism is a cavity, which is connected to the vacuum degas equipment and the atmospheric degas equipment respectively, and valve control switches are set at the connection on both sides. The cavity can be evacuated and gas can be introduced. When it is necessary to connect the vacuum degas equipment environment, the transfer mechanism cavity is evacuated, and then the end connected to the vacuum degas equipment is opened to transport the wafer. When it is necessary to connect the atmospheric degas equipment environment, the vacuum environment is first broken, and then the end connected to the atmospheric degas equipment is opened to transport the wafer.

[0038] The present invention also provides a control method for a multi-wafer degas system, comprising the following steps:

[0039] Step 1, transfer multiple wafers to the atmospheric degas equipment chamber for degas treatment, and the degas treatment time is 80% of the normal time. The wafer enters the chamber through the inlet and outlet, and the initial position of the inlet and outlet is aligned with the support block at the bottom level of the storage mechanism. After the robot places a wafer, the electric cylinder controls the moving plate to rise, and then the robot places the wafer again. The distance that the moving plate rises each time is the distance between adjacent support blocks, so that the inlet and outlet can always correspond to a group of support blocks. Every time the inlet and outlet rise, the robot puts a wafer until the storage mechanism is full of wafers. The heating lamps installed around the storage mechanism heat the wafers on the storage mechanism to remove impurities. The pump is connected to the manual valve 24 to evacuate the inside of the cavity to remove the impurities removed by heating.

[0040] Step 2: After the processing in step 1 is completed, the processed wafer is placed in a vacuum and atmosphere transfer mechanism for storage.

[0041] Step 3, transfer multiple wafers in the vacuum and atmosphere transfer mechanism to the chamber of the vacuum degas equipment for degas treatment, and the degas treatment time is 20% of the normal time. Specifically, before the vacuum degas equipment works, close the connection between the vacuum degas equipment and the process platform, open the connection between the vacuum degas equipment and the vacuum and atmosphere transfer mechanism (the chamber of the atmosphere transfer mechanism should be evacuated in advance), and transfer multiple wafers in the vacuum and atmosphere transfer mechanism to the chamber of the vacuum degas equipment. The initial position of the inlet and outlet is aligned with the support block of the top level of the storage mechanism, and the storage mechanism is controlled by the electric cylinder to rise. The distance of each rise is the distance between the adjacent wafer support plates. Each time it rises, a wafer is transported to the storage mechanism. After multiple rises, the storage mechanism is full of wafers. Vacuum for degas treatment, the heating lamp heats the wafer, and the pump removes the impurities.

[0042] Step 4: After the degas treatment is completed, open the connection between the vacuum degas equipment and the process platform, transport the wafer to the process platform for subsequent processing, and then close the connection between the vacuum degas equipment and the process platform.

[0043] In this example, the atmospheric degas processing time accounts for 80% of the total degas processing time, and the vacuum degas processing time accounts for 20% of the total degas processing time. This ratio can be further adjusted, but the overall adjustment is based on the atmospheric degas processing time accounting for a higher proportion. It is usually best if the atmospheric degas processing time accounts for more than three quarters.

[0044] It should be noted that the above content only illustrates the technical idea of ​​the present invention and cannot be used to limit the protection scope of the present invention. For ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications all fall within the protection scope of the claims of the present invention.

Claims

1. Wafer multi-wafer degas system, characterized by: include: Atmospheric degas equipment, a vacuum and atmosphere transfer mechanism connected to the atmospheric degas equipment, and a vacuum degas equipment connected to the vacuum and atmosphere transfer mechanism, wherein the vacuum degas equipment is also connected to a process platform; the vacuum degas equipment comprises a cavity and a driving mechanism, a wafer inlet and outlet are arranged on the cavity, a wafer storage mechanism is arranged in the cavity, and the driving mechanism drives the wafer storage mechanism to move up and down; the atmospheric degas equipment comprises a cavity and a driving mechanism, a wafer storage mechanism is arranged in the cavity, a movable door plate is arranged on the wafer inlet and outlet side of the cavity, a wafer inlet and outlet are arranged on the movable door plate, and the driving mechanism drives the movable door plate to move up and down, and at least one air outlet is distributed on the edge of the wafer inlet and outlet, and the air outlet is connected to the air inlet pipe.

2. The multi-wafer degas system according to claim 1, characterized in that: The outlet direction of the air outlet is perpendicular to the wafer in and out direction.

3. The multi-wafer degas system according to claim 1, characterized in that: In the atmospheric degas device, both ends of the wafer inlet and outlet are connected to the sliders through connectors respectively, and slide rails are arranged on both sides outside the cavity, and the sliders are arranged in the slide rails and move along the slide rails.

4. The multi-wafer degas system according to claim 1, characterized in that: The film storage mechanism comprises a plurality of supporting blocks arranged in parallel.

5. The multi-wafer degas system according to claim 4, characterized in that: The edge of the support block of the sheet storage mechanism of the atmospheric degas device has a slope.

6. The multi-wafer degas system according to claim 1, characterized in that: Folding edges are arranged on both sides of the movable door panel.

7. The multi-wafer degas system according to claim 6, characterized in that: The height of the folded edge protruding from the cavity surface is greater than the thickness of the movable door panel.

8. A control method for a multi-wafer degas system, characterized in that: The multi-wafer degas system according to any one of claims 1 to 7 is implemented, wherein the atmospheric degas processing time is greater than the vacuum degas processing time, comprising the following steps: Step 1: Transfer multiple wafers from the wafer inlet and outlet to the atmospheric degas equipment chamber. The initial position of the wafer inlet and outlet is aligned with the bottom support block of the wafer storage mechanism. After the robot places a wafer, the electric cylinder controls the moving plate to rise. Then the robot places another wafer, and the electric cylinder controls the moving plate to rise again. This is repeated until the wafer storage mechanism is full of wafers. The distance the moving plate rises each time is the distance between adjacent support blocks. Step 2, heating the wafer on the wafer storage mechanism to remove impurities, evacuating the inside of the chamber to remove the impurities removed by heating, and performing degas treatment; Step 3, after the processing in step 2 is completed, the processed wafer is transferred to a vacuum and atmosphere transfer mechanism; Step 4, closing the connection between the vacuum degas equipment and the process platform, opening the connection between the vacuum degas equipment and the vacuum and atmosphere transfer mechanism, the vacuum and atmosphere transfer mechanism has been evacuated, and transferring the multiple wafers in the vacuum and atmosphere transfer mechanism to the vacuum degas equipment cavity; Step 5: vacuum degas equipment is used to evacuate the wafer for degas treatment, a heating lamp heats the wafer, and the removed impurities are pumped away by a pump; Step 6: After the vacuum degas treatment is completed, open the connection between the vacuum degas equipment and the process platform, transport the wafer to the process platform for subsequent processing, and then close the connection between the vacuum degas equipment and the process platform.

9. The control method of a multi-wafer degas system according to claim 8, characterized in that: In step 4, the process of transferring multiple wafers in the vacuum and atmosphere transfer mechanism to the vacuum degas equipment chamber includes: the initial positions of the wafer inlet and outlet are aligned with the top support block of the wafer storage mechanism. After a wafer is transported to the wafer storage mechanism, the electric cylinder controls the wafer storage mechanism to rise. The distance of each rise is the distance between adjacent wafer support plates. Each rise transports a wafer to the wafer storage mechanism until the wafer storage mechanism is full of wafers.

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