Method for improving particle defects in a de-gluing process and de-gluing apparatus

Abstract

This application discloses a method and apparatus for improving particle defects in a desizing process, comprising: providing a plasma desizing chamber; defining a first inner ring region and a first outer ring region on the surface of a filter plate in the chamber, the first outer ring region corresponding to a first aggregate region formed when polymer is deposited in a conventional desizing process; performing an improved desizing process by reducing a first temperature difference between the first outer ring region and the first inner ring region to weaken the polymer deposition ability on the first outer ring region, causing the boundary of a second aggregate region formed when polymer is deposited to shift outward, and forming a second outer ring region and a second inner ring region corresponding to the second aggregate region; and performing an improved automatic cleaning process by reducing a second temperature difference between the second outer ring region and the second inner ring region to improve the cleaning efficiency of the polymer, thereby avoiding wafer particle defects caused by polymer peeling.

Description

Technical Field

[0001] This application relates to the field of semiconductor processing technology, and in particular to a method and equipment for improving particle defects in resist removal processes. Background Technology

[0002] When using a plasma photoresist stripping chamber for wafer stripping, after a certain number of wafers have undergone the stripping process, the polymer formed from the etched photoresist gradually deposits onto the surface of the filter plate used for ion filtering on an ion filter device located above the wafer stage. Furthermore, due to the structure of the ion filter device, temperature differences, and the cleaning capability of the chamber's automatic cleaning process, the polymer mainly deposits on the edge region (outer ring region) of the filter plate surface. As the polymer thickness accumulates on the edge region, in the middle and later stages of the stripping cycle, the polymer is prone to peeling off under stress and falling onto the wafer surface. These fallen particles also mainly accumulate on the edge region of the wafer surface, leading to defects in subsequent processes and ultimately affecting yield. With the continuous development of semiconductor process technology, the requirements for wafer particle defect control are becoming increasingly stringent, especially in advanced processes, which pose challenges to particle count control on the equipment. Therefore, it is necessary to research a process method that can significantly improve the above-mentioned problems. Summary of the Invention

[0003] The purpose of this application is to overcome the above-mentioned problems in the prior art and to provide a method and equipment for improving particle defects in the degumming process.

[0004] To achieve the above objectives, the technical solution of this application is as follows:

[0005] According to a first aspect of this application, embodiments of this application provide a method for improving particle defects in a degumming process, comprising:

[0006] A plasma debinding chamber is provided, wherein a stage and an ion filtering device are provided in the chamber, the ion filtering device is provided with a filter plate for filtering ions, the filter plate is located directly above the stage, and the stage is used to place wafers.

[0007] A first inner ring region and a first outer ring region located outside the first inner ring region are defined on the surface of the filter plate facing the stage. The first outer ring region corresponds to the first aggregate region formed when the polymer formed by etching photoresist in a conventional photoresist removal process is deposited on the surface of the filter plate.

[0008] By performing an improved resist removal process on the wafer and reducing the first temperature difference between the first outer ring region and the first inner ring region, the deposition ability of the polymer on the first outer ring region is weakened, and the inner boundary of the second aggregation region formed when the polymer is deposited on the first outer ring region is pushed to the outside of the first inner ring region. As a result, a second outer ring region corresponding to the second aggregation region and a second inner ring region located within the second outer ring region are formed on the surface of the filter plate. The boundary of the second inner ring region is located outside the boundary of the first inner ring region, and the first temperature difference is negative.

[0009] By performing an improved automatic cleaning process on the cavity and reducing the second temperature difference between the second outer ring region and the second inner ring region, the cleaning rate of the polymer deposited on the second outer ring region is increased, and the polymer peeling is avoided to prevent wafer particle defects. The second temperature difference is a negative value.

[0010] In some embodiments, reducing the first temperature difference between the first outer ring region and the first inner ring region, and reducing the second temperature difference between the second outer ring region and the second inner ring region, includes at least one of the following methods: reducing the ability of the first outer ring region to conduct heat to the sidewall of the cavity, and increasing the temperature of the first outer ring region.

[0011] In some embodiments, reducing the ability of the first outer ring region to conduct heat to the sidewall of the cavity includes a method for thinning the wall thickness of the flange connection portion of the ion filter device located outside the first outer ring region.

[0012] In some embodiments, the flange connection includes a connected horizontal lug and a vertical neck, the lug being for connecting to the sidewall of the cavity, the neck connecting to the first outer ring region, and the wall thickness of the flange connection being reduced includes at least one method of reducing the wall thickness of the lug and reducing the wall thickness of the neck.

[0013] In some embodiments, the method further includes: adding a ring of ion filter holes on the outside of the first outer ring region that is correspondingly vacated due to the thinning of the neck wall, so as to further reduce the deposition ability of polymer on the edge of the first outer ring region and improve the cleaning rate of polymer deposited on the edge of the second outer ring region.

[0014] In some embodiments, when the wall thickness of the ear loop is reduced, the wall thickness of the ear loop is reduced to 2 mm; when the wall thickness of the neck is reduced, the wall thickness of the neck is reduced to 5 mm.

[0015] In some embodiments, increasing the temperature of the first outer ring region includes a method of auxiliary heating the first outer ring region by providing a first heating device on the side wall of the cavity during the execution of the improved adhesive removal process, and a method of at least one of providing auxiliary heating of the first outer ring region by providing a first heating device on the side wall of the cavity during the execution of the improved automatic cleaning process, and providing auxiliary radiant heating of the first outer ring region by providing a second heating device on the platform.

[0016] In some embodiments, the process further includes: when performing the improved automatic cleaning process, increasing the flow rate of cleaning gas introduced through a first air inlet provided on the top of the cavity above the filter plate to clean the surface of the filter plate, or providing a second air inlet on the side wall of the cavity below the filter plate and introducing cleaning gas through the second air inlet to clean the surface of the filter plate, thereby increasing the cleaning rate and improving the cleaning uniformity.

[0017] In some embodiments, the cleaning gas includes nitrogen, hydrogen, and oxygen.

[0018] In some embodiments, the flow rate of the clean gas introduced through the first air inlet is 3000 sccm to 4000 sccm.

[0019] In some embodiments, the flow rate of the clean gas introduced through the second air inlet is 500 sccm to 1000 sccm.

[0020] According to a second aspect of this application, embodiments of this application also provide a desmearing device, including a cavity, a stage and an ion filter device in the cavity, the ion filter device having a filter plate for filtering ions, the filter plate being located directly above the stage, the stage being used to place a wafer, the desmearing device using the method for improving particle defects in the desmearing process provided in any embodiment of the first aspect above, performing an improved desmearing process on the wafer and an improved automatic cleaning process on the cavity.

[0021] The embodiments of this application may have, or at least have, the following advantages:

[0022] (1) By performing an improved desizing process on the wafer and reducing the first temperature difference between the first outer ring region and the first inner ring region defined on the filter plate surface, the deposition ability of the polymer on the first outer ring region can be weakened, and the inner boundary of the polymer deposition region (second aggregation region) can be pushed outward, thereby reducing the deposition thickness of the polymer throughout the entire improved desizing process cycle and narrowing the deposition area of ​​the polymer. Furthermore, by performing an improved automatic cleaning process on the cavity and reducing the second temperature difference between the second outer ring region and the second inner ring region corresponding to the polymer deposition region, the cleaning rate of the polymer deposited on the second outer ring region can be improved. Therefore, it is possible to effectively prevent the deposited polymer from peeling off and falling onto the wafer surface in the middle and later stages of the improved desizing process cycle, thereby significantly improving wafer particle defects and increasing yield.

[0023] (2) By thinning the wall thickness of the flange connection located outside the first outer ring region on the ion filter device, the heat conduction capacity of the first outer ring region to the side wall of the cavity can be reduced; by setting a first heating device on the side wall of the cavity, or by setting a second heating device on the platform, the first outer ring region can be auxiliaryly heated. Therefore, the temperature of the first outer ring region can be significantly increased, and the first temperature difference and the second temperature difference can be significantly reduced, thereby achieving the dual effect of reducing the polymer deposition thickness when performing the improved degumming process and increasing the cleaning rate of the polymer when performing the improved automatic cleaning process, greatly improving the effect of improving particle defects in the degumming process.

[0024] (3) By reducing the wall thickness of the vertically set neck on the flange connection, a radial width corresponding to the reduced thickness can be left on the outer side of the first outer ring area. Therefore, the space added in this part can be used to add a ring of ion filter holes, which not only further weakens the heat conduction ability of the first outer ring area to the side wall of the cavity, but also expands the range of plasma gas flow, thereby further weakening the deposition ability of polymer on the edge of the first outer ring area and improving the cleaning rate of polymer deposited on the edge of the second outer ring area.

[0025] (4) By setting a second air inlet on the side wall of the cavity below the filter plate, and by introducing cleaning gas through the second air inlet when performing the improved automatic cleaning process on the cavity, the surface of the filter plate can be cleaned, which can significantly increase the cleaning rate of the polymer deposited on the second outer ring area.

[0026] Therefore, the embodiments of this application can reduce the deposition ability of polymers, increase the cleaning rate of deposited polymers, and significantly improve the uniformity of cleaning.

[0027] Other advantages of this application will be described in the following detailed description. Attached Figure Description

[0028] Figure 1 This is a flowchart of a method for improving particle defects in a degumming process, provided as a preferred embodiment of this application.

[0029] Figure 2 This is a schematic diagram of a descaling device provided in a preferred embodiment of this application.

[0030] Figure 3 This application provides a comparative schematic diagram of the partial structure of a filter plate before and after improvement, according to a preferred embodiment; wherein... Figure 3 (a) Before the improvement, Figure 3 (b) is the improved version.

[0031] Figure 4 This application provides a preferred embodiment of a schematic diagram comparing the changes in polymer deposition state on the surface of a filter plate before and after improvement; wherein... Figure 4 (a) To improve the initial state before / after, Figure 4 (b) Figure 4 (c) shows the intermediate and late stages before improvement, respectively. Figure 4 (d) and Figure 4 (e) represents the improved mid-term and late-term states, respectively.

[0032] Figure 5 This is a schematic diagram showing a comparison of cleaning rates before and after improvement, provided as a preferred embodiment of this application.

[0033] Figure 6 This is a schematic diagram showing a comparison of temperature distribution before and after improvement, provided as a preferred embodiment of this application.

[0034] In the figure: 1. Second air inlet; 2. Cavity; 3. Lower cavity; 4. Upper cavity; 5. First air inlet; 6. Ion filter device; 7. Filter plate; 8. Stage; 9. Flange connection; 10. Lug; 11. Neck; 12. Ion filter hole. Detailed Implementation

[0035] In existing resist stripping processes, during the later stages of the stripping cycle, polymers are prone to peeling off under stress and falling onto the wafer surface, causing defects in subsequent processes and ultimately affecting yield. This application provides a method to improve particle defects in the resist stripping process, including:

[0036] A plasma debinding chamber is provided, wherein a stage and an ion filtering device are provided in the chamber, the ion filtering device is provided with a filter plate for filtering ions, the filter plate is located directly above the stage, and the stage is used to place wafers.

[0037] A first inner ring region and a first outer ring region located outside the first inner ring region are defined on the surface of the filter plate facing the stage. The first outer ring region corresponds to the first aggregate region formed when the polymer formed by etching photoresist in a conventional photoresist removal process is deposited on the surface of the filter plate.

[0038] By performing an improved resist removal process on the wafer and reducing the first temperature difference between the first outer ring region and the first inner ring region, the deposition ability of the polymer on the first outer ring region is weakened, and the inner boundary of the second aggregation region formed when the polymer is deposited on the first outer ring region is pushed to the outside of the first inner ring region. As a result, a second outer ring region corresponding to the second aggregation region and a second inner ring region located within the second outer ring region are formed on the surface of the filter plate. The boundary of the second inner ring region is located outside the boundary of the first inner ring region, and the first temperature difference is negative.

[0039] By performing an improved automatic cleaning process on the cavity and reducing the second temperature difference between the second outer ring region and the second inner ring region, the cleaning rate of the polymer deposited on the second outer ring region is increased, and the polymer peeling is avoided to prevent wafer particle defects. The second temperature difference is a negative value.

[0040] This application embodiment, by performing an improved resist removal process on the wafer and reducing the first temperature difference between the first outer ring region and the first inner ring region defined on the filter plate surface, can weaken the polymer deposition ability on the first outer ring region, reduce the polymer deposition thickness throughout the entire resist removal process cycle, and narrow the polymer deposition area. Furthermore, by performing an improved automatic cleaning process on the cavity and reducing the second temperature difference between the second outer ring region and the second inner ring region corresponding to the polymer deposition area, the cleaning rate of the polymer deposited on the second outer ring region can be improved, thereby significantly improving wafer particle defects and increasing yield.

[0041] This application also provides a resist stripping device for performing the above-described method for improving particle defects in the resist stripping process, thereby improving wafer particle defects.

[0042] The specific embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0043] refer to Figure 1 In a first aspect, embodiments of this application provide a method for improving particle defects in a degumming process, which may sequentially include the following steps:

[0044] Step S11: Provide a plasma degumming chamber, which is equipped with a filter plate for filtering ions.

[0045] refer to Figure 2 In some embodiments, a resist stripping device can be used to perform the method for improving particle defects in the resist stripping process provided in the embodiments of this application, so as to improve wafer particle defects. The resist stripping device includes a cavity 2 (i.e., plasma resist stripping cavity 2) for resist stripping using a plasma resist stripping method. The cavity 2 is provided with a stage 8 and an ion filter device 6. The ion filter device 6 is provided with a filter plate 7 for filtering ions in the plasma, and the filter plate 7 is densely distributed with a plurality of ion filter holes (see reference). Figure 3 The filter plate 7 is horizontally positioned directly above the stage 8, dividing the cavity 2 into two relatively independent upper and lower parts: an upper cavity 4 located above the filter plate 7 and a lower cavity 3 located below the filter plate 7. The upper cavity 4 and the lower cavity 3 together constitute the cavity 2. The stage 8 is used to place wafers that need to undergo plasma resist removal. A first air inlet 5 is provided on the top of the cavity 2 (upper cavity 4). The first air inlet 5 is used to introduce process gas used in the resist removal process and cleaning gas used in the automatic cavity cleaning process. The process gas and cleaning gas can be excited in the upper cavity 4 to form plasma. When passing through the filter plate 7 into the lower cavity 3, the plasma can be filtered out by the filter plate 7 to remove charged ions, thereby performing plasma resist removal on the wafers placed on the stage 8. Alternatively, the cavity 2 can be plasma cleaned when the stage 8 is empty (without wafers).

[0046] Step S12: Define a first inner ring region and a first outer ring region outside the first inner ring region on the surface of the filter plate. The first outer ring region corresponds to the first aggregate region formed when the polymer formed by etching the photoresist in the conventional photoresist removal process is deposited on the surface of the filter plate.

[0047] refer to Figure 4 (a), which shows the surface of the filter plate 7 facing the stage 8. Figure 2 The lower surface of the filter plate 7. In some embodiments, the filter plate 7 may be circular (but is not limited thereto). A first inner ring region R1 and a first outer ring region R2 surrounding the first inner ring region R1 may be defined on the surface (lower surface) of the filter plate 7. The first inner ring region R1 and the first outer ring region R2 together occupy the entire lower surface of the filter plate 7. The first outer ring region R2 corresponds to the first aggregate region formed when the polymer formed by etching the photoresist is deposited on the surface of the filter plate 7 in a conventional photoresist stripping process (the initial state of the improved filter plate 7 is shared with the initial state of the filter plate before improvement). Figure 4 (a) Reflection).

[0048] During the middle and late stages of the conventional plasma photoresist stripping process in cavity 2, there is a chance of particulate matter falling off. The fallen particles mainly accumulate on the edge areas of the wafer surface. Observation and investigation suggest that the particles are peeled off and fall from the edge of the filter plate surface of the ion filter. In the conventional plasma photoresist stripping process, after a certain number of wafers have undergone the stripping process, the polymer formed by etching the photoresist will deposit on the filter plate surface, and the deposition thickness at different locations on the filter plate surface is affected by the structure of the ion filter and the cleaning process.

[0049] Figure 4 (a) shows that before the improvement (existing state), there was no polymer deposition on the first inner ring region R1 and the first outer ring region R2 in the initial stage of the conventional desizing process. Figure 4 (b) shows that during the intermediate stage of a conventional desizing process, there is no polymer deposition on the first inner ring region R1, while a certain amount of polymer deposition has been deposited on the first outer ring region R2 (distinguished by a first gray color on the first outer ring region R2). Figure 4 (c) shows that in the later stages of the conventional desizing process, there is still no polymer deposition on the first inner ring region R1, while there is a relatively large amount of polymer deposition on the first outer ring region R2 (distinguished by a second gray color on the first outer ring region R2, the second gray color being darker than the first gray, indicating a thicker polymer deposition).

[0050] In the middle and later stages of a conventional depolymerization process, as the polymer continues to accumulate on the first outer ring region R2 of the filter plate surface, it may peel off and fall onto the wafer surface under stress. The fallen particles mainly accumulate on the edge area of ​​the wafer surface, causing defects in subsequent processes and ultimately affecting the yield.

[0051] Analysis of the formation mechanism of the aforementioned particulate defects led to the following findings:

[0052] (1) The conventional chamber automatic cleaning process is performed after the conventional resist removal process of a certain number of wafers. By testing the cleaning rate of the filter plate surface under the existing cleaning process, it was found that the cleaning rate of the first outer ring region R2 is about 3 times slower than that of the first inner ring region R1. The specific data are shown in Table 1 below. In Table 1, the cleaning rate is expressed in micrometers (the thickness of polymer removed per unit time), and the temperature is expressed in degrees Celsius (°C). Under the conventional chamber automatic cleaning process, the cleaning rate of the first outer ring region R2 is 1.3 micrometers, and the cleaning rate of the first inner ring region R1 is 3.8 micrometers.

[0053] Table 1:

[0054]

[0055] (2) By testing the temperature distribution of the filter plate under the existing structure during the conventional cleaning process, it is shown that the temperature of the first outer ring region R2 is 120°C and the temperature of the first inner ring region R1 is 154°C. The temperature of the first outer ring region R2 is 34°C lower than the temperature of the first inner ring region R1 (see Table 1).

[0056] (3) Attempts were made to improve the uniformity of the conventional cleaning process itself, but test data showed that the cleaning rate ratio of the first inner ring area R1 to the first outer ring area R2 was greater than 3:1.

[0057] The temperatures of the first outer ring region R2 and the first inner ring region R1 during the conventional adhesive removal process are close to the temperatures of the first outer ring region R2 and the first inner ring region R1 during the conventional automatic cavity cleaning process.

[0058] In summary, temperature differences affect the polymer cleaning rate and are the main reason for the uneven polymer deposition thickness between the first inner ring region R1 and the first outer ring region R2. Therefore, conventional descaling processes and conventional automated cleaning processes can be improved through the specific methods provided in steps S13 and S14 of the embodiments of this application below.

[0059] Step S13: Perform an improved degumming process. By reducing the first temperature difference between the first outer ring region and the first inner ring region, the deposition ability of the polymer on the first outer ring region is weakened, and the inner boundary of the second aggregation region formed when the polymer is deposited on the first outer ring region is pushed to the outside of the first inner ring region. A second outer ring region corresponding to the second aggregation region and a second inner ring region located within the second outer ring region are formed on the surface of the filter plate.

[0060] The method for improving particle defects in the degumming process provided in this application improves the existing conventional degumming process to form a new improved degumming process.

[0061] By performing an improved resist removal process on the wafer, and by reducing the temperature difference (first temperature difference) between the first outer ring region R2 and the first inner ring region R1 during the improved resist removal process, the deposition ability of the polymer on the first outer ring region R2 can be weakened. This causes the inner boundary of the deposition area (second aggregation region) formed when the polymer deposits on the first outer ring region R2 to shift outwards towards the first inner ring region R1 (i.e., towards the edge of the filter plate 7). Consequently, a second outer ring region r2 corresponding to the second aggregation region and a second inner ring region r1 located within (surrounded by) the second outer ring region r2 are formed on the surface of the filter plate 7, with the boundary of the second inner ring region r1 located outside the boundary of the first inner ring region R1. In other words, by weakening the polymer deposition ability on the first outer ring region R2, the deposition thickness of the polymer throughout the entire resist removal process cycle is reduced, and the deposition width of the polymer on the surface of the filter plate 7 (the radial width of the second outer ring region r2) is narrowed, thus reducing the deposition area.

[0062] The temperature of the first outer ring region R2 is lower than that of the first inner ring region R1. Therefore, the first temperature difference (the difference between the temperatures of the first outer ring region R2 and the first inner ring region R1) is negative. When the improved degumming process reduces the first temperature difference (i.e., the temperature of the first outer ring region R2 increases), the polymer deposition ability on the first outer ring region R2 is weakened (the higher the temperature, the more difficult it is for the polymer to deposit), the deposition rate on the first outer ring region R2 is slowed down, and the width of the deposition area is narrowed, forming a second outer ring region r2 that recedes outward. Thus, even if the polymer still deposits on the first outer ring region R2, the stress effect is correspondingly reduced because the deposition thickness and deposition range are smaller throughout the entire degumming process cycle, making it less easy for the polymer to peel off and fall off. At the same time, the relatively smaller deposition thickness and deposition range also help improve the automatic cleaning capability of the cavity, providing a clean and well-maintained surface for the filter plate 7 in the next degumming process cycle, greatly reducing (or even eliminating) the cumulative effect of the polymer film layer, thus forming a long-term virtuous cycle.

[0063] Still with Figure 4 (a) Reflects that, after the improvement by the embodiments of this application, no polymer deposition is found on the defined first inner ring region R1 and first outer ring region R2 in the initial stage of the improved degumming process. Figure 4 (d) shows that in the intermediate stage of the improved degumming process, there is no polymer deposition on the second inner ring region r1 and only a small amount of polymer deposition on the second outer ring region r2 (distinguished by a third gray color on the second outer ring region r2). Figure 4(e) shows that in the later stage of the improved degumming process, there is no polymer deposition on the second inner ring region r1, while the amount of polymer deposition on the second outer ring region r2 has increased (distinguished by a fourth gray color on the second outer ring region r2; the second gray, first gray, fourth gray, and third gray colors decrease in color from dark to light to reflect the decreasing thickness of the polymer deposition). It can be seen that the radial width of the second outer ring region r2 is significantly narrower than that of the first outer ring region R2, indicating that in the improved degumming process, the ability of polymer to deposit radially on the surface of the filter plate 7 is significantly reduced compared to the conventional degumming process, and the deposition thickness is also significantly reduced.

[0064] Step S14: Perform an improved automatic cleaning process to improve the cleaning efficiency of the polymer deposited on the second outer ring area by reducing the second temperature difference between the second outer ring area and the second inner ring area, thereby preventing polymer peeling and wafer particle defects.

[0065] The method for improving particle defects in the degumming process provided in this application improves the existing conventional automatic cavity cleaning process to form a new improved automatic cavity cleaning process.

[0066] By performing an improved automated cleaning process (improved cavity automated cleaning process) on cavity 2, and by reducing the temperature difference (second temperature difference) between the second outer ring region r2 and the second inner ring region r1 corresponding to the polymer deposition area (second aggregation region) during the improved automated cleaning process, the cleaning rate of the polymer deposited on the second outer ring region r2 can be improved. Therefore, it is possible to effectively prevent the deposited polymer from peeling off and falling onto the wafer surface in the middle and later stages of the improved desizing process cycle (the improved desizing process cycle can remain unchanged or be appropriately extended compared to the conventional desizing process cycle), thereby significantly improving wafer particle defects and increasing yield.

[0067] The second temperature difference (the difference between the temperature of the second outer ring region r2 and the temperature of the second inner ring region r1) can also be negative. When the improved automatic cleaning process reduces the second temperature difference (i.e., the temperature of the second outer ring region r2 is increased), the cleaning rate of the polymer deposited on the second outer ring region r2 can be significantly improved (the higher the temperature, the greater the cleaning ability of the polymer).

[0068] In some embodiments, reducing the first temperature difference between the first outer ring region R2 and the first inner ring region R1, and reducing the second temperature difference between the second outer ring region r2 and the second inner ring region r1, may include at least one of the methods of weakening the thermal conductivity of the first outer ring region R2 (the second inner ring region r1 is contained within the first outer ring region R2) to the sidewall of the cavity 2 and increasing the temperature of the first outer ring region R2. On the one hand, when the thermal conductivity of the first outer ring region R2 is weakened, the rate of thermal conductivity of the first outer ring region R2 to the sidewall of the cavity 2 is slowed down, and therefore the heat of the first outer ring region R2 is effectively retained (not easily dissipated), thereby reducing the first temperature difference and the second temperature difference. On the other hand, if the temperature of the first outer ring region R2 is increased, the first temperature difference and the second temperature difference are directly reduced. Thus, the ability of polymer to deposit on the first outer ring region R2 is weakened, and the cleaning rate of polymer deposited on the second outer ring region r2 is increased.

[0069] In some embodiments, reducing the ability of the first outer ring region R2 to conduct heat to the sidewall of the cavity 2 may include a method of thinning the wall thickness of the flange connection portion located outside the first outer ring region R2 on the filter plate 7 of the ion filter device 6.

[0070] refer to Figure 2 and Figure 3 In some embodiments, the ion filtering device 6 is generally connected to the side wall of the cavity 2 via a connection structure located around the filter plate 7 (outside the first outer ring region R2). The connection structure is typically a flange-type connection part (connecting flange), such as the flange connection part 9 in the embodiments of this application, and the side wall of the cavity 2 is provided with a corresponding mounting mating part that mates with the flange connection part 9. Figure 3 (b) shows the direction of the center (inner side) and edge (outer side) of filter plate 7 with horizontal double arrows.

[0071] The flange connection 9 may include a horizontally arranged lug 10 and a vertically arranged neck 11. The outer end of the lug 10 is used to connect with a mounting mating part on the side wall of the cavity 2, the inner end of the lug 10 is connected to the upper end of the neck 11, and the lower end of the neck 11 is connected to the outer side of the filter plate 7 (outer side of the first outer ring region R2). Reducing the wall thickness of the flange connection 9 includes at least one method of reducing the wall thickness of the lug 10 and reducing the wall thickness of the neck 11.

[0072] Figure 3 (b) shows an example in which the wall thickness of the lug 10 and the neck 11 were both reduced. Figure 3 (a) shows a partial structure of the existing filter plate before improvement. Figure 3(b) shows a partial structure of the filter plate 7 of the improved embodiment of this application, wherein H1 represents the wall thickness of the existing ear portion, H2 represents the wall thickness of the ear portion 10 of the present application embodiment, L1 represents the wall thickness of the existing neck portion, and L2 represents the wall thickness of the neck portion 11 of the present application embodiment. Figure 3 (a) and Figure 3 (b) As can be seen, after the improvement, the wall thickness H2 of the ear loop 10 and the wall thickness L2 of the neck 11 in this embodiment of the application are significantly thinner than the wall thickness H1 of the existing ear loop and the wall thickness L1 of the existing neck, thereby significantly reducing the ability of the first outer ring region R2 of the filter plate 7 to conduct heat to the side wall of the cavity 2, thereby reducing the first temperature difference and the second temperature difference.

[0073] In one example, the wall thickness H2 of the ear loop 10 in this embodiment is reduced from the existing 4mm or more to 2mm, and the wall thickness L2 of the neck 11 in this embodiment is reduced from the existing 10mm or more to 5mm. The thickness is basically reduced by half, which greatly reduces the ability of the first outer ring region R2 to dissipate heat to the side wall of the cavity 2. In addition, the structural strength and installation stability of the filter plate 7 can be ensured by providing reinforcing ribs around the mounting holes on the ear loop 10 (i.e., the wall thickness of the ear loop 10 around the mounting holes remains the original thickness).

[0074] In some embodiments, due to the thinning of the neck 11 of the flange connection 9, the inner side of the neck 11 is pushed to the outer side of the filter plate 7 by a certain distance, which is the reduced wall thickness of the neck 11. As a result, the first outer ring region R2 expands (empties) a corresponding radial distance to the outer side. Therefore, at least one ring of ion filter holes 12 can be added to the outer side of the first outer ring region R2, which is correspondingly emptied due to the thinning of the wall thickness of the neck 11. This not only further reduces the heat conduction ability of the first outer ring region R2 to the side wall of the cavity 2, but also expands the effective range of the plasma gas flow. This further reduces the deposition ability of polymer on the edge of the first outer ring region R2 and improves the cleaning rate of polymer deposited on the edge of the second outer ring region R2.

[0075] refer to Figure 3 In one example, Figure 3 (a) shows that the first outer ring region R2 before improvement had 5 (rings) of ion filter holes. Figure 3(b) shows that the improved first outer ring region R2 has 6 (rings) of ion filter holes 12, which is one more ring of ion filter holes 12 compared to the original. This improvement significantly reduces the distance between the outermost ring of ion filter holes 12 and the edge of the filter plate 7 compared to the original. Therefore, under the action of the airflow flowing through the ion filter holes 12, the deposition ability of polymer on the edge of the first outer ring region R2 will be significantly reduced, and the cleaning rate of polymer deposited on the edge of the second outer ring region R2 will be improved.

[0076] In some embodiments, increasing the temperature of the first outer ring region R2 includes a method of auxiliary heating the first outer ring region R2 by providing a first heating device (not shown) on the sidewall of the cavity 2 during the execution of an improved desizing process. By providing the first heating device to heat the first outer ring region R2 in reverse, the temperature of the first outer ring region R2 can be directly increased, thereby reducing the first temperature difference and the second temperature difference.

[0077] In some embodiments, increasing the temperature of the first outer ring region R2 includes at least one of the following methods during the execution of the improved automatic cleaning process: assisting the heating of the first outer ring region R2 by providing a first heating device on the side wall of the cavity 2, and assisting the radiative heating of the first outer ring region R2 by providing a second heating device (not shown) on the stage 8. Specifically, by providing reverse heating of the first outer ring region R2 by providing the first heating device, and / or by providing auxiliary radiative heating of the first outer ring region R2 by the second heating device itself on the stage 8, the temperature of the first outer ring region R2 can be directly increased, thereby reducing the first temperature difference and the second temperature difference. It should be noted that when heating by the second heating device on the stage 8, the stage 8 should be in an unloaded state, and the water cooling device on the stage 8 should be turned off, allowing the filter plate 7 to receive more heat radiation and rapidly increase its temperature.

[0078] Therefore, by increasing the temperature of the first outer ring region R2, the first temperature difference and the second temperature difference are significantly reduced. This achieves a dual effect: reducing the polymer deposition thickness when performing the improved degumming process and increasing the cleaning rate of the polymer when performing the improved automatic cleaning process. This greatly enhances the effect of improving particle defects in the degumming process.

[0079] In some embodiments, the first heating device may include a resistance heater, an infrared heater, or a heating lamp, etc.

[0080] In some embodiments, the second heating device may be configured using current and future heating device design standards for degumming equipment.

[0081] In some embodiments, when performing the improved automatic cleaning process, the surface of the filter plate 7 is cleaned by increasing the flow rate of the cleaning gas introduced through the first air inlet 5 provided on the top of the cavity 2 (upper cavity 4) above the filter plate 7 (relative to the flow rate of the cleaning gas in the conventional automatic cleaning process), thereby improving the cleaning ability of polymers deposited on the surface of the filter plate 7, increasing the cleaning rate, and improving the cleaning uniformity (U%).

[0082] In some embodiments, when performing the improved automatic cleaning process, a second air inlet 1 is provided on the side wall of the cavity 2 (lower cavity 3) below the filter plate 7, and cleaning gas is introduced through the second air inlet 1 to clean the surface of the filter plate 7. This can improve the cleaning ability of polymers deposited on the surface of the filter plate 7, increase the cleaning rate, and improve the cleaning uniformity.

[0083] In some embodiments, the cleaning gas may include a mixture of nitrogen and hydrogen, as well as oxygen, etc.

[0084] In some embodiments, when cleaning gas is introduced through the first air inlet 5, the flow rate of the cleaning gas can be 3000 sccm to 4000 sccm, which is not less than twice the flow rate of the cleaning gas in a conventional automatic cleaning process.

[0085] In some embodiments, when cleaning gas is introduced through the second air inlet 1, the flow rate of the cleaning gas can be 500 sccm to 1000 sccm.

[0086] Table 1 lists a set of improvement data obtained after testing the improved filter plate 7, which had reduced thermal conductivity, and after implementing the improved automatic cleaning process of the embodiments of this application. Figure 5 The diagram shows a comparison of cleaning rates before and after the improvement, plotted based on the cleaning rate data in Table 1. Figure 6 A schematic diagram comparing the temperature distribution of the filter plate before and after improvement, based on the temperature data in Table 1, is shown. Figure 5 The left and right sides of the image represent the cleaning rates before and after the improvement, respectively. From left to right, they represent the cleaning rate at the center of the filter plate 7 surface (denoted by C), the cleaning rate at the middle of the filter plate 7 surface (located between the center and the edge, denoted by M), and the cleaning rate at the edge of the filter plate 7 surface (denoted by E). The diagonal line represents the cleaning uniformity U%. Figure 5 Data on the cleaning rate (M) of the middle part of the surface of filter plate 7 has been added. Figure 6 The left and right sides of the table represent the temperature distribution of the filter plate before and after improvement, respectively. From left to right, they represent the center temperature of the filter plate 7 surface (denoted as Center) and the edge temperature of the filter plate 7 surface (denoted as Edge). The diagonal line represents the temperature difference between the center and the edge (denoted as CE temperature difference). (From Table 1 and...) Figure 5 , Figure 6 As can be seen, after the improvement, the temperature of the second outer ring region r2 (corresponding to the edge temperature) increased to 163℃, which is 43℃ ​​higher than the temperature of the first outer ring region R2 (corresponding to the edge temperature) before the improvement (120℃). The temperature of the second inner ring region r1 (corresponding to the center temperature) also increased to 188℃, which is 34℃ higher than the temperature of the first inner ring region R1 (corresponding to the center temperature) before the improvement (154℃). The temperature difference between the center and the edge (the second temperature difference) decreased from 34℃ before the improvement to 25℃ after the improvement, and the temperature difference reduction rate reached 26%. Correspondingly, after the improvement, the cleaning rate of the second outer ring region r2 increased to 5.5 micrometers, which is 4.2 micrometers higher than the cleaning rate of the first outer ring region R2 (1.3 micrometers) before the improvement. The cleaning rate of the second inner ring region r1 also increased to 12.1 micrometers, which is 8.3 micrometers higher than the cleaning rate of the first inner ring region R1 (3.8 micrometers) before the improvement (the cleaning rate in the center also increased from 2.5 micrometers to 9.6 micrometers). Overall, the cleaning rate was improved by about 4 times. The cleaning uniformity U% between the center and the edge increased from 49.02% before the improvement to 37.50% after the improvement, with a cleaning uniformity improvement rate of 24%. The above results indicate that increasing the temperature of the first outer ring region R2 (second outer ring region r2) ultimately improved the cleaning ability of the deposited polymer.

[0087] Through on-machine testing of the improved filter plate 7 with reduced thermal conductivity, the results also showed that the polymer deposition area on the surface of the filter plate 7 was narrowed (the radial width of the second outer ring region r2 was reduced compared to the radial width of the first outer ring region R2), and the polymer deposition thickness was significantly reduced in the middle and later stages of the improved degumming process, resulting in a significant improvement in cleaning ability in the improved automatic cleaning process (reference). Figure 4 (d) and Figure 4 (e) and Figure 4 (b) and Figure 4 (Comparison between (c)). The particulate matter monitoring results were good, and there were no more problems with particulate matter falling off, thus effectively improving the particle defects in the degumming process and making it suitable for widespread application.

[0088] In a second aspect, embodiments of this application also provide a resist stripping apparatus. The resist stripping apparatus uses the method for improving particle defects in the resist stripping process provided in any of the embodiments of the first aspect above to perform an improved resist stripping process on the wafer and an improved automatic cleaning process on the cavity 2.

[0089] refer to Figure 2 and Figure 3The resist removal equipment includes a plasma resist removal chamber 2, which contains a stage 8 and an ion filter device 6. The ion filter device 6 has a filter plate 7 for filtering ions, with multiple (circles) of ion filter holes 12 densely distributed on the filter plate 7. The filter plate 7 is located directly above the stage 8 and divides the chamber 2 into an upper chamber 4 above the filter plate 7 and a lower chamber 3 below the filter plate 7. The stage 8 is used to place the wafer to be resisted.

[0090] In some embodiments, the method for improving particle defects in the degumming process using the degumming equipment may include a method for reducing the ability of the first outer ring region R2 defined on the filter plate 7 to conduct heat to the sidewall of the cavity 2. For example, reducing the ability of the first outer ring region R2 to conduct heat to the sidewall of the cavity 2 may include a method for reducing the wall thickness of the flange connection 9 located outside the first outer ring region R2 of the filter plate 7.

[0091] Furthermore, an improved method may be included, which involves adding at least one ring of ion filter holes 12 on the outer side of the first outer ring region R2 that is correspondingly vacated due to the thinning of the wall thickness of the neck 11 of the flange connection 9.

[0092] In some embodiments, the method for improving particle defects in the degumming process using the degumming equipment may include an improvement method for increasing the temperature of a first outer ring region R2 defined on the filter plate 7 during the execution of the improved degumming process and the improved automatic cleaning process. For example, increasing the temperature of the first outer ring region R2 may include an improvement method for auxiliary heating of the first outer ring region R2 by providing a first heating device on the side wall of the cavity 2 during the execution of the improved degumming process. Alternatively, it may include at least one of the following improvement methods during the execution of the improved automatic cleaning process: auxiliary heating of the first outer ring region R2 by providing a first heating device on the side wall of the cavity 2, and auxiliary radiant heating of the first outer ring region R2 by a second heating device provided on the stage 8.

[0093] In some embodiments, the method for improving particle defects in the degumming process used in the degumming equipment may include an improved method for cleaning the surface of the filter plate 7 (plasma cleaning) by increasing the flow rate of the cleaning gas introduced through the first air inlet 5 when performing an improved automatic cleaning process.

[0094] In some embodiments, the method for improving particle defects in the degumming process using the degumming equipment may include an improved method for cleaning the surface of the filter plate 7 by providing a second air inlet 1 on the side wall of the lower cavity 3 and introducing cleaning gas through the second air inlet 1 when performing an improved automatic cleaning process.

[0095] By optimizing and combining the above-mentioned improvement methods as an integral part of the improved degumming process and improved automatic cleaning process implemented in the embodiments of this application, the degumming equipment implements the improved degumming process and improved automatic cleaning process to realize the method of improving particle defects in the degumming process in the embodiments of this application, so as to effectively improve particle defects in the degumming process.

[0096] In summary, the embodiments of this application, by performing an improved resist removal process on the wafer and reducing the first temperature difference between the first outer ring region R2 and the first inner ring region R1 defined on the surface of the filter plate 7, can weaken the deposition ability of the polymer on the first outer ring region R2, reduce the deposition thickness of the polymer throughout the entire resist removal process cycle, and narrow the deposition area of ​​the polymer. Furthermore, by performing an improved automatic cleaning process on the cavity 2 and reducing the second temperature difference between the second outer ring region r2 and the second inner ring region r1 corresponding to the polymer deposition area, the cleaning rate of the polymer deposited on the second outer ring region r2 can be improved, and the uniformity of cleaning can be significantly improved, thereby significantly improving wafer particle defects and increasing yield.

[0097] The above are merely preferred embodiments of this application. These embodiments are not intended to limit the scope of protection of this application. Therefore, any equivalent changes made based on the description and drawings of this application should also be included within the scope of protection of this application.

Claims

1. A method for improving particle defects in a degumming process, characterized in that, include: A plasma debinding chamber is provided, wherein a stage and an ion filtering device are provided in the chamber, the ion filtering device is provided with a filter plate for filtering ions, the filter plate is located directly above the stage, and the stage is used to place wafers. A first inner ring region and a first outer ring region located outside the first inner ring region are defined on the surface of the filter plate facing the stage. The first outer ring region corresponds to the first aggregate region formed when the polymer formed by etching photoresist in a conventional photoresist removal process is deposited on the surface of the filter plate. By performing an improved resist removal process on the wafer and reducing the first temperature difference between the first outer ring region and the first inner ring region, the deposition ability of the polymer on the first outer ring region is weakened, and the inner boundary of the second aggregation region formed when the polymer is deposited on the first outer ring region is pushed to the outside of the first inner ring region. As a result, a second outer ring region corresponding to the second aggregation region and a second inner ring region located within the second outer ring region are formed on the surface of the filter plate. The boundary of the second inner ring region is located outside the boundary of the first inner ring region, and the first temperature difference is negative. By performing an improved automatic cleaning process on the cavity and reducing the second temperature difference between the second outer ring region and the second inner ring region, the cleaning rate of the polymer deposited on the second outer ring region is increased, and the polymer peeling is avoided to prevent wafer particle defects. The second temperature difference is a negative value.

2. The method for improving particle defects in the degumming process according to claim 1, characterized in that, The reduction of the first temperature difference between the first outer ring region and the first inner ring region, and the reduction of the second temperature difference between the second outer ring region and the second inner ring region, include at least one of the following methods: reducing the ability of the first outer ring region to conduct heat to the sidewall of the cavity, and increasing the temperature of the first outer ring region.

3. The method for improving particle defects in the degumming process according to claim 2, characterized in that, The method of reducing the ability of the first outer ring region to conduct heat to the side wall of the cavity includes a method of thinning the wall thickness of the flange connection portion of the ion filter device located outside the first outer ring region.

4. The method for improving particle defects in the degumming process according to claim 3, characterized in that, The flange connection includes a connected horizontal lug and a vertical neck. The lug is used to connect to the side wall of the cavity, and the neck connects to the first outer ring region. When the wall thickness of the flange connection is reduced, it includes at least one method of reducing the wall thickness of the lug and reducing the wall thickness of the neck.

5. The method for improving particle defects in the degumming process according to claim 4, characterized in that, Also includes: An ion filter hole is added to the outside of the first outer ring area, which is correspondingly vacated due to the thinning of the neck wall, to further reduce the deposition ability of polymer on the edge of the first outer ring area and improve the cleaning rate of polymer deposited on the edge of the second outer ring area.

6. The method for improving particle defects in the degumming process according to claim 4, characterized in that, When thinning the wall thickness of the ear loop, the wall thickness of the ear loop is reduced to 2mm; when thinning the wall thickness of the neck, the wall thickness of the neck is reduced to 5mm.

7. The method for improving particle defects in the degumming process according to claim 2, characterized in that, The method of increasing the temperature of the first outer ring region includes a method of auxiliary heating the first outer ring region by providing a first heating device on the side wall of the cavity during the execution of the improved adhesive removal process, and a method of at least one of the following: auxiliary heating the first outer ring region by providing a first heating device on the side wall of the cavity during the execution of the improved automatic cleaning process, and auxiliary radiant heating of the first outer ring region by providing a second heating device on the platform.

8. The method for improving particle defects in the degumming process according to claim 1, characterized in that, Also includes: When performing the improved automatic cleaning process, the surface of the filter plate is cleaned by increasing the flow rate of the cleaning gas introduced through the first air inlet provided on the top of the cavity above the filter plate, or by providing a second air inlet on the side wall of the cavity below the filter plate and introducing cleaning gas through the second air inlet, thereby increasing the cleaning rate and improving the cleaning uniformity.

9. The method for improving particle defects in the degumming process according to claim 8, characterized in that, The cleaning gas includes nitrogen, hydrogen, and oxygen; and / or, the flow rate of the cleaning gas introduced through the first inlet is 3000 sccm to 4000 sccm, and the flow rate of the cleaning gas introduced through the second inlet is 500 sccm to 1000 sccm.

10. A glue-removing device, characterized in that, The device includes a cavity, in which a stage and an ion filter are provided. The ion filter is provided with a filter plate for filtering ions. The filter plate is located directly above the stage. The stage is used to place a wafer. The resist removal equipment uses the method for improving particle defects in the resist removal process as described in any one of claims 1-9 to perform an improved resist removal process on the wafer and an improved automatic cleaning process on the cavity.

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