A degassing chamber for PVD equipment

Abstract

The present invention discloses a degassing chamber for PVD equipment, comprising a PVD chamber, wherein a heater is arranged in the PVD chamber, a first cooling cover is arranged on one side, and a second cooling cover is arranged on the other side; a first ejector pin is arranged on the heater, and a second ejector pin is arranged on the outer side; a first rotating shaft is arranged on the side of the first cooling cover, a first cooling structure is arranged on the first rotating shaft, the first rotating shaft is used to rotate the first cooling structure into the first cooling cover or above the heater, and a first opening structure for the first ejector pin to pass through is arranged on the first cooling structure; a second rotating shaft is arranged on the side of the second cooling cover, a mechanical arm is arranged on the second rotating shaft, the mechanical arm is movably connected with the second cooling structure, and the second rotating shaft rotates the second cooling structure into the second cooling cover or above the heater through the mechanical arm. The present invention utilizes the time that the wafer stays in the degassing chamber to cool the wafer, reduces the subsequent cooling time, and improves the machine production capacity.

Description

Technical Field

[0001] The invention relates to the technical field of semiconductor manufacturing, in particular to a degassing chamber for PVD equipment. Background Art

[0002] Semiconductor PVD equipment has a degassing chamber to heat the wafer and remove surface impurities.

[0003] The existing technical equipment is composed of: a degassing chamber with a carrier heater inside, and the surface of the heater has grooves. The existing process principle is: there is a metal heating plate on the heater, which is equivalent to a resistor. A direct current is passed for heating, and there is also a metal heat-conducting plate above the heating plate. The heater is generally heated to a surface temperature of between 200 and 400°, and the wafer is transferred to the top of the heater. At this time, argon gas is sent into the chamber. The argon molecules will enter the grooves of the heater, and the argon molecules will contact the heater. The heat is conducted to the argon molecules. As a medium, the argon molecules will conduct the heat to the back of the wafer again. The wafer will be heated. When the temperature of the wafer rises, the water vapor, impurities, etc. adsorbed on the surface of the wafer will be removed. The purpose of degassing is achieved.

[0004] The original process flow is: chamber door opens → wafer is transferred to heater ejector by arm → arm retracts and chamber door closes → ejector drops wafer onto heater surface → argon is introduced for about 10 seconds to reach pressure of 7~10Torr → maintain for 60~90 seconds → evacuate for 10 seconds to vacuum → wafer is transferred out of chamber → change to cooling chamber for cooling.

[0005] The problem with the prior art is that after the wafer is heated and adsorbed water vapor and impurities are removed, it needs to be cooled. In the prior art, it needs to be transferred to other chambers for cooling. In addition, the temperature of the wafer waiting to be transferred in the degassing chamber will further rise during the process of waiting for transfer, resulting in a longer subsequent cooling time, thereby greatly reducing production efficiency.

[0006] That is to say, after high-temperature degassing, the wafer needs to be cooled before entering the main process chamber. Generally, the machine will have a special cooling chamber to cool the wafer. However, in the general process, due to the different process times of each chamber, there will be a phenomenon that the wafer will wait after the degassing chamber is finished. Waiting in the degassing chamber will make the wafer temperature rise higher, which means that it will take longer to cool in the cooling chamber, wasting time. Summary of the invention

[0007] In view of the deficiencies in the prior art, the present invention provides a degassing chamber for PVD equipment. The present invention utilizes the time that the wafer stays in the degassing chamber to cool the wafer, thereby reducing subsequent cooling time and improving machine production capacity.

[0008] To achieve the above object, the present invention provides the following technical solutions:

[0009] A degassing chamber for a PVD device comprises a PVD chamber, wherein a heater is arranged in the PVD chamber, a first cooling cover is arranged on one side, and a second cooling cover is arranged on the other side; a first ejector pin is arranged on the heater, and a second ejector pin is arranged on the outer side; a first rotating shaft is arranged on the side of the first cooling cover, a first cooling structure is arranged on the first rotating shaft, the first rotating shaft is used to rotate the first cooling structure into the first cooling cover or above the heater, and a first opening structure for the first ejector pin to pass through is arranged on the first cooling structure; a second rotating shaft is arranged on the side of the second cooling cover, a mechanical arm is arranged on the second rotating shaft, the mechanical arm is movably connected with the second cooling structure, and the second rotating shaft rotates the second cooling structure into the second cooling cover or above the heater through the mechanical arm.

[0010] As a further solution of the present invention, the first cooling structure and the second cooling structure are both disc structures.

[0011] As a further solution of the present invention, the orthographic projection areas of the second cooling structure, the first cooling structure and the heater decrease in sequence.

[0012] As a further solution of the present invention, three first ejector pins are arranged on the heater, and three first opening structures are correspondingly arranged on the first cooling structure.

[0013] As a further solution of the present invention, the first opening structure is an arc-shaped opening structure.

[0014] As a further solution of the present invention, the second ejector pins are distributed in a triangular shape in the PVD cavity.

[0015] As a further solution of the present invention, the first ejector pins are used to lift the wafer and place the wafer on the upper surface of the first cooling structure.

[0016] As a further solution of the present invention, the second ejector pin is used to lift up the second cooling structure and bring the second cooling structure close to the upper surface of the wafer.

[0017] As a further solution of the present invention, a supporting structure is provided on the robotic arm for supporting the second cooling structure.

[0018] As a further solution of the present invention, the first cooling structure and the second cooling structure are used to wrap the wafer during the cooling process.

[0019] The present invention has the following beneficial effects:

[0020] The present invention adds two cooling covers on the side of the cavity to store the cooling structure when the wafer starts to degas. After high-temperature degassing, the cooling structure is used to cover the wafer to isolate the heat source, thereby achieving the effect of cooling the wafer; the heat source above and below the wafer can be isolated. A major feature of the present invention is that it can isolate the local heat source and cool the wafer in a targeted manner, which is different from the existing method of cooling the entire chamber, thereby greatly saving energy and time.

[0021] The present invention improves the process mainly after high-temperature degassing by improving the process. By designing a cooling structure to wrap the wafer, the degassed wafer can be quickly cooled, the waiting time of the wafer in the degassing chamber can be reduced, and the time for subsequent entry into the main process chamber can be saved, thereby greatly improving work efficiency.

[0022] In order to more clearly illustrate the structural features and effects of the present invention, the present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the existing chamber structure mentioned in the present invention.

[0024] Figure 2 It is a structural schematic diagram of a degassing chamber for PVD equipment of the present invention.

[0025] Figure 3 It is a partial top view of a degassing chamber for PVD equipment according to the present invention.

[0026] Figure 4 , Figure 5 It is a partial schematic diagram of the first rotating shaft and the first cooling structure mentioned in the present invention in different directions.

[0027] Figure 6 , Figure 7 A partial schematic diagram of the second rotating shaft and the second cooling structure mentioned in the present invention in different directions. DETAILED DESCRIPTION

[0028] The present invention will be further explained below in conjunction with the accompanying drawings and related knowledge, and described clearly and completely. Obviously, the described application is only a part of the embodiments of the present invention, rather than all the embodiments.

[0029] After the existing semiconductor wafers are degassed at high temperature, they need to be cooled before entering the main process chamber. Generally, the machine will have a special cooling chamber to cool the wafers. However, in the general process, due to the different process times of each chamber, there will be a phenomenon that the wafers wait after the degassing chamber is finished. Waiting in the degassing chamber will make the wafer temperature rise higher, and it will need to be cooled in the cooling chamber for a longer time, which wastes time.

[0030] Reference Figure 1 As shown in the figure, the schematic diagram of the existing chamber structure, the working process is: the chamber 1 door is opened, and the wafer 2 is transferred to the heater ejector by the arm; the arm retracts the chamber door and closes the door; the ejector 3 drops the wafer and is placed on the surface of the heater 4; the cold pump plug valve 5 is closed; argon is introduced through the argon inlet pipe 6 for about 10 seconds to reach a pressure of 7~10Torr → maintained for 60~90 seconds; the cold pump plug valve evacuates for 10 seconds to vacuum; the wafer is transferred to the cooling chamber for cooling. In the existing technology, the wafer needs to be transferred to the cooling chamber for cooling, and there will be a phenomenon that the wafer waits after the degassing chamber is finished. Waiting in the degassing chamber will make the wafer temperature rise higher, and it needs to be cooled in the cooling chamber for a longer time, which wastes time.

[0031] Based on the above problems, the present invention is proposed, and the specific embodiments are as follows:

[0032] See also Figure 2-Figure 7 As shown, a degassing chamber for a PVD device comprises a PVD chamber, wherein a chamber 1 is provided, a heater 4 is arranged in the PVD chamber, a first cooling cover 7 is arranged on one side, and a second cooling cover 12 is arranged on the other side; a first ejector pin 3 is arranged on the heater 4, and a second ejector pin 11 is arranged on the outer side, referring to Figure 2 As shown, the first ejector pin 3 is located on the heater 4, and the second ejector pin 11 is located outside the heater 4, inside the degassing chamber, and is in a contracted state during degassing; a first rotating shaft 8 is provided on the side of the first cooling cover 7, and a first cooling structure 9 is provided on the first rotating shaft 8. The first rotating shaft 8 is used to rotate the first cooling structure 9 into the first cooling cover 7 or above the heater 4, and a first opening structure 10 for the first ejector pin 3 to pass through is provided on the first cooling structure 9; a second rotating shaft 13 is provided on the side of the second cooling cover 12, and a mechanical arm 14 is provided on the second rotating shaft 13. The mechanical arm 14 is movably connected to the second cooling structure 15, and the second rotating shaft 13 rotates the second cooling structure 15 into the second cooling cover 12 or above the heater 4 through the mechanical arm 14. Figure 2 As shown, the purpose of the present invention is to cool the wafer after degassing, and rapid directional cooling can be achieved. The specific implementation process is: after the degassing is completed, the wafer 2 is lifted up by the first ejector pin 3, and at this time, the first cooling structure 9 is rotated between the heater 4 and the wafer 2 by the first rotating shaft 8, referring to Figure 4 , Figure 5As shown, at this time, since the first cooling structure 9 is provided with a first opening structure 10 for the first ejector 3 to pass through, when the first cooling structure 9 is located between the heater 4 and the wafer 2, the first ejector is lowered so that the lower surface of the wafer 2 contacts the upper surface of the first cooling structure 9; then the second cooling structure 15 is driven to move above the wafer 2 by the second rotating shaft 13 and the mechanical arm 14, and then the second ejector 11 lifts the second cooling structure 15, the mechanical arm 14 is withdrawn into the second cooling cover 12, and then the second ejector 11 is lowered to the upper surface of the wafer 2. This process can be controlled by the PCL control system, and the descending height of the second ejector 11 can be accurately controlled. The descending height is controlled to be between 0.5mm and 1.5mm from the upper surface of the wafer 2. In some wafer products, it can be directly slightly contacted, that is, the descending height can be controlled according to different wafers. This design method can be applied to different wafers and has stronger applicability. The advantages of this design method are: it can avoid the influence of the upper heating strip and the lower heater 4 on the cooling of the wafer, thereby achieving the effects of directional isolation and directional cooling, and can greatly save cooling time.

[0033] In the present invention, both the first cooling structure 9 and the second cooling structure 15 are disc structures, wherein the disc structure of the first cooling structure 9 is provided with a circulating refrigerant, preferably cooling water. It should be noted that the cooling water can be designed in a conventional manner, and the disc structure of the second cooling structure 15 can be a cold plate made of metal material, for example, a structure for condensing the second cooling structure 15 is provided in the second cooling cover 12. Figure 2 As shown, the second cooling structure 15 is located in the second cooling cover 12, and condensation is applied to the second cooling structure 15 through the second cooling cover 12. The specific condensation method is not limited, for example, a method similar to the condensation principle of a refrigerator can be adopted. It should be noted in the present invention that in order to achieve better condensation effect and cooling effect on the wafer, an upper and lower opening and closing structure can also be provided between the first cooling cover 7, the second cooling cover 12 and the degassing chamber, that is, during the degassing process, the upper and lower opening and closing structures are in a closed state. When the degassing is completed, the opening and closing structure opens, and the first rotating shaft 8 and the second rotating shaft 13 start working, driving the first cooling structure 9 and the second cooling structure 15 to cool the wafer.

[0034] It should be noted in the present invention that the process of the present invention is different from other processes, mainly reflected in that when other process chambers are cooled down, the temperature is not cooled down to a large extent, for example, the temperature can be cooled down by cooling gas, while the process of the present invention requires that the temperature needs to be raised to 200~400° during degassing, which is a very high temperature. How to achieve rapid cooling at this high temperature is the core point of the present invention. To achieve rapid cooling after high temperature, the design of the present invention saves cooling time and improves cooling efficiency; and more importantly, it can avoid the waiting time of the wafer after degassing that exists in the prior art.

[0035] In the present invention, for ease of understanding, Figure 2 It is marked that the second cooling structure 15 is located in the second cooling cover 12 and above the wafer.

[0036] In the present invention, the orthographic projection areas of the second cooling structure 15, the first cooling structure 9, and the heater 4 are reduced successively, which can facilitate the wafer to descend to the upper surface of the first cooling structure 9, and facilitate the second cooling structure 15 to descend to the upper surface of the wafer and cover the wafer, thereby facilitating rapid cooling of the wafer.

[0037] In the present invention, three first ejector pins are arranged on the heater, and three first opening structures 10 are correspondingly arranged on the first cooling structure 9, which are used to pass the first ejector pins, lift the wafer by the first ejector pins, and then place the wafer on the upper surface of the first cooling structure 9, which can greatly improve the cooling efficiency.

[0038] In the present invention, reference is made to Figure 5 As shown, the first opening structure 10 is an arc-shaped opening structure. By designing the arc-shaped structure, it can facilitate the passage of the first ejector pin during the rotation process, and the structure can isolate the heat source of the heater below as much as possible; in order to better isolate the heat source, it is preferred that a layer of heat insulation film is coated on the lower surface of the first cooling structure 9.

[0039] In the present invention, the second ejector pin 11 is located in the PVD chamber in a triangular distribution, and its main function is to lift the second cooling structure 15 and lower it to the top of the wafer. According to product requirements, the lower surface of the second cooling structure 15 is preferably at a distance of 0.5mm-1.5mm from the upper surface of the wafer, which can cool the wafer and isolate the heat source. That is to say, in the present invention, the first ejector pin is used to lift the wafer and place the wafer on the upper surface of the first cooling structure, and the second ejector pin is used to lift the second cooling structure and place the second cooling structure close to the upper surface of the wafer. During the cooling process, the first cooling structure and the second cooling structure are used to wrap the wafer.

[0040] In the present invention, the first ejector pin 3 is used to lift the wafer 2 and place the wafer 2 on the first cooling structure 9; directly placing the wafer 2 on the surface of the first cooling structure 9 can achieve direct contact between the wafer and the refrigerant, which can greatly improve the cooling speed.

[0041] In the present invention, a support structure 16 is provided on the robot arm 14 for supporting the second cooling structure. The support structure preferably adopts a non-heat-conducting structure. Further, in order to better realize the present invention, the robot arm 14 is a telescopic robot arm 14. For example, in the process of retracting the second cooling structure, the robot arm 14 is first moved to a specified position, and then the robot arm is extended to support the second cooling structure, and then the second ejector pin is retracted, and then the second cooling structure is retracted into the second cooling cover 12, thereby completing a cycle operation.

[0042] New process flow: chamber door opens → wafer is transferred to heater ejector by arm → arm retracts chamber door and closes → ejector falls and wafer falls on heater surface → argon is introduced for about 10 seconds to reach 7~10Torr pressure → hold for 60~90 seconds → first cooling structure and second cooling structure are moved to below and above wafer respectively to wrap wafer and hold for 30 seconds → evacuate for 10 seconds to vacuum → move two cooling structures back to cooling cover → wafer is transferred out of chamber. Thus, after high-temperature degassing, the wafer is covered with cooling structure to isolate heat source, so as to achieve the effect of cooling wafer. Compared with the prior art, the present invention can save more than one minute of cooling time.

[0043] The present invention can realize that most of the degassing chambers used in the industry are high-temperature degassing, so the temperature of the wafer after degassing is very high, so a cooling chamber is needed to cool the wafer to maintain the stability of the subsequent process. If the wafer can be directly cooled in the high-temperature degassing chamber, the next process can be carried out directly without going to the cooling chamber to cool the wafer. The present invention uses the time that the wafer stays in the degassing chamber to cool the wafer, reduce the subsequent cooling time, and improve the machine production capacity.

[0044] The process of the present invention is particularly suitable for cooling the wafer after degassing. It can quickly cool the high-temperature wafer and completely isolate the heat source. It will not cause the temperature of the wafer to rise during the waiting process in the prior art. It can save a cooling chamber and greatly improve the cooling efficiency.

[0045] The present invention can be implemented in semiconductor manufacturing, where the high-temperature degassing chamber commonly used in the industry will increase the temperature of the wafer. A cooling chamber is usually required to cool the wafer to ensure the stability of the subsequent process. If the wafer can be directly cooled in the high-temperature degassing chamber, the step of transferring the wafer to the cooling chamber can be omitted, and the next process can be directly entered. This can not only simplify the process flow and improve production efficiency, but also reduce the risk of damage to the wafer during the transfer process, reduce problems such as particle contamination, and help improve product yield. This design of the cooling hood makes its contact area with the wafer larger, and the wafer can be cooled from multiple directions, and the heat transfer is more uniform and efficient, thereby obtaining a better cooling effect and faster cooling efficiency.

[0046] The technical principle of the present invention is described above in combination with the specific embodiments, which are only preferred implementations of the present invention. The protection scope of the present invention is not limited to the above embodiments, and all technical solutions under the idea of ​​the present invention belong to the protection scope of the present invention. Those skilled in the art can think of other specific implementations of the present invention without creative work, and these methods will fall within the protection scope of the present invention.

Claims

1. A degassing chamber for a PVD device, characterized in that: The invention comprises a PVD chamber, wherein a heater is arranged in the PVD chamber, a first cooling cover is arranged on one side, and a second cooling cover is arranged on the other side; a first ejector pin is arranged on the heater, and a second ejector pin is arranged on the outer side; a first rotating shaft is arranged on the side of the first cooling cover, a first cooling structure is arranged on the first rotating shaft, the first rotating shaft is used to rotate the first cooling structure into the first cooling cover or above the heater, and a first opening structure for the first ejector pin to pass through is arranged on the first cooling structure; a second rotating shaft is arranged on the side of the second cooling cover, a mechanical arm is arranged on the second rotating shaft, the mechanical arm is movably connected with the second cooling structure, the second rotating shaft rotates the second cooling structure into the second cooling cover or above the heater through the mechanical arm, three first ejectors are arranged on the heater, and three first opening structures are correspondingly arranged on the first cooling structure, the first opening structure is an arc-shaped opening structure, the first ejector pin is used to lift the wafer and place the wafer on the upper surface of the first cooling structure, and the second ejector pin is used to lift the second cooling structure and place the second cooling structure close to the upper surface of the wafer.

2. A degassing chamber for a PVD device as claimed in claim 1, characterized in that: The first cooling structure and the second cooling structure are both disc structures.

3. A degassing chamber for a PVD device as claimed in claim 1, characterized in that: The orthographic projection areas of the second cooling structure, the first cooling structure and the heater decrease in sequence.

4. A degassing chamber for a PVD device as claimed in claim 1, characterized in that: The second ejector pins are located in the PVD cavity and distributed in a triangular shape.

5. A degassing chamber for a PVD device as claimed in claim 1, characterized in that: A supporting structure is provided on the mechanical arm for supporting the second cooling structure.

6. A degassing chamber for a PVD device as claimed in claim 1, characterized in that: During the cooling process, the first cooling structure and the second cooling structure are used to wrap the wafer.

Images