Method for removing polymer residues
By using a shunt to form a pulsed airflow in the plasma etching process, the arc discharge and maintenance cost problems caused by polymer residue are solved, and more efficient cleaning and maintenance are achieved.
Patent Information
- Application Number
- CN202510189928.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-20
- Publication Date
- 2025-06-20
AI Technical Summary
In the plasma etching process, polymer remains in the tiny gap between the upper electrode plate and the cooling plate, resulting in arc discharge and equipment damage, increasing maintenance costs and cycles.
By passing the process gas into the diverter, a pulsed air flow is formed using the pressure difference between the first and second pipes, and repeated N times to remove polymer residues between the cooling plate and the upper electrode plate in the chamber.
It effectively reduces polymer residue, shortens maintenance cycle, reduces maintenance costs, and improves the stability and reliability of equipment.
Smart Images
Figure CN120184048A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of semiconductor manufacturing, and in particular relates to a method for removing polymer residues. Background Art
[0002] Plasma etching is one of the key steps in the integrated circuit manufacturing process, and its etching effect directly affects the product quality of the integrated circuit. In a typical plasma etching process, different process gas combinations (such as C x F y , O2, Ar, etc.) in a radio frequency (RF) environment to form plasma. The formed plasma physically bombards and chemically reacts with the wafer surface under the action of the upper and lower electrode electric fields of the etching chamber (reaction chamber of plasma etching equipment) to complete the processing of wafer surface design patterns and key processes.
[0003] In the existing dry etching process, it is usually necessary to carry out in the etching chamber. As the number of wafers processed continues to increase, the internal environment in the etching chamber will change accordingly. The upper electrode plate (CEL body: Si) and the lower electrode of the etching reaction chamber form upper and lower capacitors, and plasma is formed through RF radio frequency drive. The upper electrode plate (CEL body: Si) is distributed with inlet holes on its surface, so that the reaction gas is injected into the reaction chamber through the inlet holes. However, see Figure 2 There is a small gap between the upper electrode plate 300 and the rear cooling plate 200. When the reaction gas is injected, the polymer residue 400 generated by the plasma is easily accumulated in the gap between the upper electrode plate 300 and the rear cooling plate 200. When a certain amount of accumulation is reached, arc discharge will occur. Figure 3 , causing damage to the surface of the upper electrode plate 300. Usually, in actual engineering, it is necessary to shorten the maintenance cycle to achieve equipment maintenance, and equipment engineers usually need to disassemble, clean and maintain the upper electrode plate and the cooling plate. Because the structures of the upper electrode plate and the cooling plate are relatively complex, it usually takes a certain amount of time to disassemble and process them. At the same time, the residual polymer deposition is also difficult to clean during the cleaning process, which requires high time cost, manpower and other maintenance costs.
[0004] Therefore, how to reduce the polymer residue under the tiny gap between the upper electrode plate and the rear cooling plate to reduce the maintenance cycle and reduce the maintenance cost has become an important technical problem that needs to be solved urgently by technicians in this field. Summary of the invention
[0005] In view of the above-mentioned disadvantages of the prior art, the object of the present invention is to provide a method for removing polymer residues, which is used to solve the problem of how to reduce polymer residues in the small gap between the upper electrode plate and the rear cooling plate, so as to reduce the maintenance cycle and lower the maintenance cost.
[0006] To achieve the above object, the present invention provides a method for removing polymer residues, which is used to remove polymer residues between the upper electrode plate and the cooling plate in a chamber, and includes the following steps:
[0007] S1, introducing a process gas into a flow divider, the flow divider including a first pipeline and a second pipeline, the first pipeline and the second pipeline corresponding to a first valve and a second valve respectively, the first pipeline and the second pipeline corresponding to a plurality of gas transmission pipelines respectively, and the gas transmission pipelines being communicated with the upper electrode plate and the cooling plate located in the chamber;
[0008] S2, setting a pressure value, and adjusting the first valve and the second valve so that there is a pressure difference ΔP between the first pipeline and the second pipeline;
[0009] S3, closing the second pipeline and opening the first pipeline so that the process gas flows out for a certain time t; closing the first pipeline and opening the second pipeline so that the process gas flows out for a certain time t;
[0010] S4, repeating the above step S3 for N times.
[0011] Optionally, the range of t is 2 to 4 s.
[0012] Optionally, the range of N is 10 to 100.
[0013] Optionally, in step S1, the pressure range of the process gas introduced into the flow divider is 50 mT to 800 mT.
[0014] Optionally, the range of ΔP is 1 to 5 T.
[0015] Optionally, the pressure values of the first pipeline and the second pipeline are tested by a pressure testing device, and the pressure testing device communicates with the flow divider.
[0016] Optionally, the first valve and the second valve are controlled to be opened and closed by a valve controller, and the valve controller communicates with the flow divider.
[0017] Optionally, the valve controller is used to output a pulsed first signal to the first valve, and the first signal is used to control the opening or closing of the first valve; the valve controller is used to output a pulsed second signal to the second valve, and the second signal is used to control the opening or closing of the second valve.
[0018] Optionally, the process gas includes one or a combination of argon, oxygen, nitrogen, and helium.
[0019] Optionally, the first pipe corresponds to the edge regions of the cooling plate and the upper electrode plate in the chamber, and the second pipe corresponds to the middle regions of the cooling plate and the upper electrode plate in the chamber.
[0020] As described above, the present invention provides a method for removing polymer residues. By introducing a process gas into a diverter, the diverter includes a first pipe and a second pipe. The first pipe and the second pipe are provided with a first valve and a second valve. The first pipe and the second pipe respectively correspond to a plurality of gas delivery pipes. By setting a pressure value, a pressure difference ΔP is formed between the first pipe and the second pipe; the second pipe is closed, and the first pipe is opened, so that the process gas flows out for a certain period of time t; the first pipe is closed, and the second pipe is opened, so that the process gas flows out for a certain period of time t. The above steps are repeated N times to form a pulsed air flow in the first pipe and the second pipe, thereby eliminating the polymer residues between the cooling plate and the upper electrode plate in the chamber. The method for removing polymer residues of the present invention not only reduces the polymer residues in the small gap between the upper electrode plate and the rear cooling plate, but also reduces the maintenance cycle, thereby reducing the maintenance cost. Description of the Drawings
[0021] Figure 1 Shown are the schematic flow diagrams of the steps for removing polymer residues according to the present invention.
[0022] Figure 2 Shown is a schematic structural diagram of polymer residues deposited between a cooling plate and an upper electrode plate in the prior art.
[0023] Figure 3 Shown is a schematic structural diagram of an arc discharge occurring in polymer residues in the prior art.
[0024] Figures 4 - 5 Shown is a schematic structural diagram of the inside of the first pipe and the second pipe when an air flow pulse is formed in an embodiment of the present invention.
[0025] Figure 6 Shown is a schematic structural diagram of the process of blowing away polymer residues by an air flow pulse in an embodiment of the present invention.
[0026] Figure 7 Shown is a schematic structural diagram of the corresponding regions of the first pipe and the second pipe in an embodiment of the present invention.
[0027] Figure 8 (a) to 8(d) show schematic structural diagrams of the circulation of an air flow pulse in the first pipe and the second pipe in an embodiment of the present invention.
[0028] Figures 9 - 10 Schematic diagram showing the pulse signal controlling the first valve and the second valve in the embodiment of the present invention.
[0029] Description of reference numerals
[0030] 100 Shunt
[0031] 110 First pipeline
[0032] 111 First valve
[0033] 112 Edge area
[0034] 120 Second pipeline
[0035] 121 Second valve
[0036] 122 Intermediate area
[0037] 200 Cooling plate
[0038] 210 Cooling plate pipeline
[0039] 300 Upper electrode plate
[0040] 310 Electrode plate pipeline
[0041] 400 Polymer residue Detailed implementation manners
[0042] The following uses specific specific examples to illustrate the implementation manners of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific implementation manners. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.
[0043] When detailing the embodiments of the present invention, for the convenience of description, the cross-sectional views showing the device structure will be enlarged locally not in accordance with the general ratio, and the schematic diagrams are only examples and should not limit the protection scope of the present invention here. In addition, in actual production, three-dimensional spatial dimensions including length, width, and depth should be included.
[0044] For ease of description, spatial relationship terms such as "below", "beneath", "lower than", "under", "above", "on" etc. may be used herein to describe the relationship of one element or feature shown in the drawings with other elements or features. It will be understood that these spatial relationship terms are intended to encompass other directions of the device in use or operation, in addition to the directions depicted in the drawings. Embodiments may include those in which the first and second features are formed in direct contact, and may also include embodiments in which additional features are formed between the first and second features, such that the first and second features may not be in direct contact. Additionally, when a layer is referred to as being "between" two layers, it may be the only layer between the two layers, or there may be one or more intervening layers.
[0045] It should be noted that the illustrations provided in this embodiment only schematically illustrate the basic concept of the present invention. Therefore, only the components related to the present invention are shown in the illustrations, rather than being drawn according to the number, shape, and size of the components in actual implementation. The type, quantity, and ratio of the components in actual implementation can be arbitrarily changed, and the component layout type may also be more complex.
[0046] Embodiment
[0047] This embodiment provides a method for removing polymer residues, which is used to remove polymer residues between the upper electrode plate and the cooling plate in the chamber. Figure 1 Schematically shows the schematic diagrams of each step process. In combination with the attached Figures 2 - 9 An introduction to the method for removing polymer residues is given.
[0048] First, refer to Figure 1 and Figure 4 , perform step S1, introduce process gas into the flow divider 100. The flow divider 100 includes a first pipeline 110 and a second pipeline 120. The first pipeline 110 and the second pipeline 120 respectively correspond to a first valve 111 and a second valve 121. The first pipeline 110 and the second pipeline 120 respectively correspond to a plurality of gas transmission pipelines, and the gas transmission pipelines are connected to the upper electrode plate 300 and the cooling plate 200 located in the chamber.
[0049] Through the setting of the flow divider 100 and the introduction of gas, gas diversion can be achieved; at the same time, the first pipeline 110 and the second pipeline 120 respectively correspond to a plurality of gas transmission pipelines. The gas transmission pipelines include a cooling plate pipeline 210 located on the cooling plate 200 and an electrode plate pipeline 310 located on the upper electrode plate 300. The diameter of the end of the electrode plate pipeline 310 adjacent to the cooling plate 200 is smaller than the diameter of the end of the cooling plate pipeline 210 adjacent to the electrode plate pipeline 310, thereby improving the flow efficiency of the gas flow to achieve the pulsed effect of the subsequent gas flow on the gap between the cooling plate 200 and the upper electrode plate 300.
[0050] For example, refer to Figure 4 , Figure 5 and Figure 7 . The first pipe 110 corresponds to the edge area 112 of the cooling plate 200 and the upper electrode plate 300 in the corresponding chamber, and the second pipe 120 corresponds to the middle area 122 of the cooling plate 200 and the upper electrode plate 300 in the corresponding chamber.
[0051] Specifically, the diverter 100 diverts the process gas to two pipes. In this embodiment, the first pipe 110 corresponds to the edge area 112 of the cooling plate 200 and the upper electrode plate 300 in the plasma etching chamber, and the second pipe 120 corresponds to the middle area 122 of the cooling plate 200 and the upper electrode plate 300 in the plasma etching chamber to enable the pulsed gas flow in the edge area 112 and the middle area 122 to circulate. The powerful pulsed gas flow passes through the gas pipelines in the cooling plate and the upper electrode plate 300, thereby removing the polymer residue 400 between the cooling plate 200 and the upper electrode plate 300 in the plasma etching chamber. Of course, in some other embodiments, the cooling plate 200 and the upper electrode plate 300 in the plasma etching chamber may further include a sub-edge area (not marked). The first pipe 110 may correspond to the edge area and the sub-edge area, and the second pipe 120 corresponds to the corresponding middle area 122, but not limited thereto, and will not be elaborated here.
[0052] For example, preferably, the pressure range of the process gas introduced into the diverter 100 is 50 mT to 800 mT, such as 50 mT, 100 mT, 150 mT, 200 mT, 300 mT, 400 mT, 500 mT, 600 mT, 700 mT, 800 mT. The setting of the pressure range of the introduced process gas can not only ensure the safety performance of the gas pipeline but also ensure the stability of the gas flow.
[0053] For example, the process gas includes one or a combination of argon, oxygen, nitrogen, and helium.
[0054] Specifically, usually under the action of physical pulses, the process gas can physically impact the gas transmission pipeline, effectively removing surface contaminants and improving the cleaning efficiency. Argon, oxygen, nitrogen, and helium have different advantages in the process of removing polymers. To avoid chemical reactions with the gas transmission pipeline, argon is usually used for physical impact, which has a better effect on the surface with higher requirements for the gas transmission pipeline. In some other embodiments, to remove organic polymers in the gas transmission pipeline, oxygen is usually used for physical impact, and at the same time, organic residues can be effectively removed. Gases such as nitrogen and helium also play a good role in the process of removing polymers, which will not be elaborated here. In practical applications, it is necessary to optimize the gas selection according to the pipeline material, pollutant type, and removal target to achieve the best removal effect.
[0055] Next, refer to Figure 1 , Figure 4 , Figure 5 and Figure 8 , and perform step S2 to set the pressure value, and adjust the first valve 111 and the second valve 121 so that there is a pressure difference ΔP between the first pipeline 110 and the second pipeline 120.
[0056] As an example, preferably, the range of ΔP is 1 - 5T. To ensure that the gas pipeline can have a better impact effect on the polymer residue 400 between the cooling plate 200 and the upper electrode plate 300 under the action of pulses, by adjusting the diverter 100, the air pressure of the first pipeline 110 is increased by 1.0 - 1.5T per second, so that the pressure difference between the first pipeline 110 and the second pipeline 120 reaches the set value ΔP, and the range of ΔP is 1 - 5T, such as any value within this range like 1T, 2T, 3T, 4T, 5T, etc. The setting of the above range not only ensures the cleaning effect of the gas pulse but also helps to maintain the airflow stability of the pulse gas and is conducive to ensuring the safety performance of the gas pipeline; of course, the range of ΔP is not limited to this, and the value range of ΔP is set according to the actual pipeline pressure and actual airflow of the equipment.
[0057] It should be noted that in this embodiment, there is no obvious front - back order and difference between the first pipeline 110 and the second pipeline 120.
[0058] As an example, the pressure values of the first pipeline 110 and the second pipeline 120 are tested by a pressure testing device (not labeled), and the pressure testing device communicates with the diverter 100 to achieve the adjustment of the gas pressure.
[0059] Specifically, the pressure testing device can monitor and collect the pressures in the first pipeline 110 and the second pipeline 120 in real time, and through communication with the flow divider 100, it can achieve real-time adjustment of the gas pressure, ensuring that the gas pressure operates stably within the set range, which helps to avoid system instability caused by pressure fluctuations and improve reliability. At the same time, the automated pressure testing and regulation system can improve the working efficiency of testing and regulation. Of course, in some other embodiments, the control of pressure is not limited to this, and details will not be elaborated here.
[0060] Next, refer to Figure 1 、 Figure 4 、 Figure 5 and Figure 8 , perform step S3, close the second pipeline 120, open the first pipeline 110, and allow the process gas to flow out for a certain period of time t; then close the first pipeline 110 and open the second pipeline 120 to allow the process gas to flow out for a certain period of time t.
[0061] Specifically, by controlling the opening and closing of the first pipeline 110 and the second pipeline 120, the process gas is switched back and forth. Under the action of the flow divider 100, the pressure difference between the first pipeline 110 and the second pipeline 120 can reach the range of ΔP described in step S2 within a certain period of time t. Thus, at the moment when the first pipeline 110 is opened, the gas pulse with a larger pressure flows into the gas transmission channels and gaps between the cooling plate 200 and the upper electrode plate 300. In this embodiment, refer to Figure 6 , the polymer residue 400 at the end of the gap between the cooling plate 200 and the upper electrode plate 300 near the gas transmission pipeline can move under the action of the gas pulse and fall onto the carrier substrate in the chamber through the gas transmission pipeline of the upper electrode plate 300, and finally be sent out of the chamber.
[0062] Furthermore, in step S2, the pressure setting of the first pipeline 110 is greater than that of the second pipeline 120. Therefore, in this step, the first pipeline 110 is opened for a certain period of time t first while the second pipeline 120 is closed, and then the second pipeline 120 is opened for a certain period of time t while the first pipeline 110 is closed. Refer to Figure 8 (a) to Figure 8 (d), the first pipeline 110 and the second pipeline 120 are cyclically opened and closed to generate a pulsed air flow. Of course, the opening and closing sequence of the first pipeline 110 and the second pipeline 120 can be operated according to the actual pressure difference between the two pipelines.
[0063] As an example, the range of t is 2 - 4s.
[0064] Specifically, in this embodiment, since the air pressure increases by 1.0 - 1.5 T per second, when the second pipeline 120 is closed and the first pipeline 110 is opened, so that the process gas flows out for a certain period of time t, the range of t is 2 - 4 s, such as any value within this range like 2 s, 2.5 s, 3 s, 3.5 s, 4 s, etc. The air pressure in the second pipeline 120 gradually rises. Within the time of 2 - 4 s, the air pressure in the second pipeline 120 can reach 1 - 5 T, such as any value within this range like 1 T, 2 T, 2.5 T, 3 T, 4 T, 5 T, etc. When the first pipeline 110 starts to be closed and the second pipeline 120 starts to be opened, the gas pulse in the second pipeline 120 can effectively remove the polymer residue 400 in the gap between the cooling plate 200 and the upper electrode plate 300 or the polymer residue 400 in the gas transmission pipeline located on the upper electrode plate 300; of course, in some other embodiments, the pulse time t is not limited to this and can be designed according to the actual length of the gas pipeline and the range of tolerable pressure.
[0065] Next, refer to Figure 1 and Figure 8 , and perform step S4, repeating the above step S3 N times.
[0066] Specifically, the pulsed air flow formed by the air pressure difference between the first pipeline 110 and the second pipeline 120 can generate a strong impact force, effectively removing the polymer residue 400 remaining between the cooling plate 200 and the upper electrode plate 300. By adopting the N - cycle steps, it can ensure that each injection of the pulsed air flow has sufficient energy to remove the residues. At the same time, the pulsed air flow can quickly and evenly remove the polymer residue 400. Due to the high - pressure and high - speed characteristics of the pulsed air flow, it can save cleaning time and energy consumption and improve cleaning efficiency.
[0067] As an example, the range of N is 10 - 100, such as any value within this range like 10, 15, 20, 40, 60, 80, 100, etc.; refer to Figures 9 - 10 , in this embodiment, the pulsed cycle of the air flow is used in the routine tests of the equipment and for the intermittent cleaning of the plasma etching cavity. Usually, the cleaning cycle is defined according to the actual residue situation after different cavities or different types of product wafers, such as cycle segments of 24 h, 72 h, 108 h, etc. Of course, in some other embodiments, the number of repetitions of the pulsed air flow also depends on various factors such as the actual material of the pipeline, the type of the polymer residue 400, and the flow rate of the air flow, so it is not limited to this and will not be elaborated here.
[0068] As an example, the first valve 111 and the second valve 121 are controlled to open and close by a valve controller (not labeled), and the valve controller communicates with the diverter 100.
[0069] Specifically, the valve controller communicates with the diverter 100, and the control mode of the valve controller includes one of manual control, electric control, pneumatic control, hydraulic control, and automatic control.
[0070] Further, in this embodiment, the first valve 111 and the second valve 121 are controlled by an automatic control valve to achieve opening and closing operations, and the valve controller communicates with the diverter 100, which enables the diverter 100 to control the opening and closing of the first valve 111 and the second valve 121, thereby realizing the adjustment and control of the gas flow path by the diverter 100. Of course, in some other embodiments, the valve controller can also adopt control modes such as electric valves, pneumatic valves, and hydraulic valves to cooperate with the diverter 100 to further control the gas flow path.
[0071] Further, as an example, refer to Figures 9 - 10 , the valve controller adopts an automatic control valve, and the valve controller is used to output a pulsed first signal to the first valve 111, and the first signal is used to control the opening or closing of the first valve 111; the valve controller is used to output a pulsed second signal to the second valve 121, and the second signal is used to control the opening or closing of the second valve 121.
[0072] Furthermore, in this embodiment, the duration t of the first signal and the second signal is selected to be 2 - 4 s, such as any value within the range of 2 s, 2.5 s, 3 s, 3.5 s, 4 s, etc. Of course, in some other embodiments, it is not limited to this, and it can be designed according to the actual length of the gas pipeline and the range of tolerable pressure.
[0073] In summary, the present invention provides a method for removing polymer residues. By introducing a process gas into a diverter, the diverter includes a first pipeline and a second pipeline. The first pipeline and the second pipeline correspond to a first valve and a second valve respectively. The first pipeline and the second pipeline respectively correspond to a plurality of gas transmission pipelines. By setting a pressure value, a pressure difference ΔP is created between the first pipeline and the second pipeline. Close the second pipeline and open the first pipeline to allow the process gas to flow out for a certain period of time t. Then close the first pipeline and open the second pipeline to allow the process gas to flow out for a certain period of time t. Repeat the above steps N times to form a pulsed gas flow in the first pipeline and the second pipeline, thereby eliminating polymer residues between the cooling plate and the upper electrode plate in the chamber. The method for removing polymer residues in the present invention not only reduces polymer residues in the small gap between the upper electrode plate and the rear cooling plate, but also reduces the maintenance cycle, thereby reducing the maintenance cost. Therefore, the present invention effectively overcomes various disadvantages in the prior art and has high industrial utilization value.
[0074] The above embodiments are only illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes completed by those with ordinary knowledge in the technical field without departing from the spirit and technical ideas disclosed by the present invention should still be covered by the claims of the present invention.
Claims
1. A method for removing polymer residues, characterized in that The following steps are involved: S1, passing the process gas into a flow divider, wherein the flow divider comprises a first pipeline and a second pipeline, wherein the first pipeline and the second pipeline correspond to a first valve and a second valve, respectively, and the first pipeline and the second pipeline correspond to a plurality of gas pipelines, respectively, and the gas pipelines are connected to an upper electrode plate and a cooling plate in the chamber; S2, setting a pressure value, adjusting the first valve and the second valve so that there is a pressure difference ΔP between the first pipeline and the second pipeline; S3, closing the second pipeline and opening the first pipeline, so that the process gas flows out for a certain time t; Closing the first pipeline and opening the second pipeline so that the process gas flows out for a certain time t; S4, repeat the above step S3 N times.
2. The method for removing polymer residues according to claim 1, characterized in that: The range of t is 2 to 4 s.
3. The method for removing polymer residues according to claim 1, characterized in that: The range of N is 10-100.
4. The method for removing polymer residues according to claim 1, characterized in that: In step S1, the pressure range of the process gas entering the diverter is 50mT to 800mT.
5. The method for removing polymer residues according to claim 1, characterized in that: The range of ΔP is 1 to 5T.
6. The method for removing polymer residues according to claim 1, characterized in that: The pressure values of the first pipeline and the second pipeline are tested by a pressure testing device, and the pressure testing device communicates with the diverter.
7. The method for removing polymer residues according to claim 1, characterized in that: The first valve and the second valve are switched on and off by a valve controller, and the valve controller communicates with the diverter.
8. The method for removing polymer residues according to claim 7, characterized in that: The valve controller is used to output a pulsed first signal to the first valve, and the first signal is used to control the first valve to open or close; the valve controller is used to output a pulsed second signal to the second valve, and the second signal is used to control the second valve to open or close.
9. The method for removing polymer residues according to claim 1, characterized in that: The process gas includes one or a combination of argon, oxygen, nitrogen and helium.
10. The method for removing polymer residues according to claim 1, characterized in that: The first pipe corresponds to the edge area of the cooling plate and the upper electrode plate in the chamber, and the second pipe corresponds to the middle area of the cooling plate and the upper electrode plate in the chamber.