Developing method
By combining a pre-wetting nozzle for developing and developing, an auxiliary developing nozzle, and a high- and low-speed cleaning nozzle that sprays deionized water and developer at multiple angles, the problems of uneven developer coverage and blind hole defects are solved, achieving uniform developer coverage and improved cleaning effect.
Patent Information
- Application Number
- CN202411148394.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-20
- Publication Date
- 2026-03-03
AI Technical Summary
In existing developing processes, uneven coverage of the developer on the photoresist surface leads to significant differences in developing reaction time, affecting the uniformity of critical dimensions. Furthermore, the high surface contact angle of the photoresist material results in insufficient wetting, causing blind hole defects and developing residues, which in turn affects the yield of the finished product.
The developing pre-wetting nozzle uses a multi-angle spray deionized water spraying nozzle, supplemented by an auxiliary developing nozzle that sprays a small amount of developing solution. The main developing nozzle performs the developing reaction, and the developing residue is cleaned by a cleaning nozzle using a combination of high and low rotation speeds and inert gas.
The developer solution provides uniform coverage, reducing blind hole defects and developer residue, improving finished product yield, and optimizing the developing process.
Smart Images
Figure CN121596691A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of semiconductor integrated circuit technology, and specifically relates to a developing method. Background Technology
[0002] With the development of integrated circuit technology, the critical dimensions in photolithography are constantly shrinking, which in turn increases the requirements for the developing process. Currently, the developing process faces two main challenges: firstly, the developing solution needs to uniformly cover the photoresist surface in a short time to reduce the impact of the developing reaction time difference on the uniformity of critical dimensions; secondly, with the continuous advancement of photolithography technology, the surface contact angle of photolithographic materials is constantly increasing, making the photoresist surface more difficult to wet.
[0003] To optimize the developing process, current processes involve spraying a measured amount of deionized water onto the silicon wafer surface before developing to improve the adhesion of the developing solution in subsequent processes. However, the pre-wetting nozzles used in current developing processes have a simple structure, and the high-speed water jets sprayed result in uneven wetting of the wafer surface or exert a certain force on the photoresist surface, thus affecting the morphology of the photoresist on the silicon wafer surface. Simultaneously, the high surface contact angle of the photoresist material can lead to insufficient wetting at the wafer center, resulting in discontinuous water films and incomplete developing. This, in turn, creates blind holes in the center of the silicon wafer within the metal trench pattern, causing the pattern to disappear or deform.
[0004] Secondly, insufficient cleaning during the development process can cause various types of development residues, thus affecting the final product yield. Therefore, in the cleaning process, spraying deionized water from the center of the wafer to the edge, combined with the high and low rotation speed of the wafer and the synergistic effect of inert gas, can greatly improve the cleaning efficiency and remove development residues. Summary of the Invention
[0005] The purpose of this invention is to provide a developing method to optimize the developing process, reduce the generation of blind hole defects in metal trench patterns, and reduce the impact of developing residues on the final yield.
[0006] To achieve the above objectives, the present invention provides a developing method comprising the following steps: S1, spraying deionized water onto the wafer surface from multiple angles through a developing pre-wetting nozzle positioned above the wafer, thereby first wetting the wafer surface; S2, spraying developing solution onto the wafer surface through an auxiliary developing nozzle, thereby second wetting the wafer surface; S3, spraying developing solution onto the wafer surface through a main developing nozzle, thereby causing the photoresist on the wafer surface to react with the developing solution; S4, spraying deionized water onto the wafer surface through a cleaning nozzle, thereby cleaning the wafer surface, rinsing away developing residues, and revealing the developed pattern.
[0007] Optionally, in S4, when the cleaning nozzle moves radially from the center of the wafer to the edge of the wafer, the rotational speed of the wafer is changed to further reduce the developer residue.
[0008] Optionally, the cleaning nozzle is positioned 5cm to 7cm above the wafer; when the cleaning nozzle sprays deionized water at the center of the wafer, the wafer rotation speed is 500r / min to 1000r / min, and the spraying time of the deionized water is 15s to 20s; when the cleaning nozzle moves radially from the center of the wafer to the edge of the wafer, the wafer rotation speed varies within the range of 1000r / min to 3000r / min, and the spraying time of the deionized water is 30s to 40s.
[0009] Optionally, the cleaning nozzle sprays deionized water onto the wafer surface and simultaneously injects nitrogen gas onto the wafer surface.
[0010] Optionally, the developing pre-wetting nozzle includes a delivery pipe, an annular guide assembly fixedly connected to the output end of the delivery pipe, and several flow dividers; wherein, the annular guide assembly includes several layers of annular partitions spaced apart along the axial direction of the delivery pipe; the flow dividers are spaced apart circumferentially along the annular partitions, fixing adjacent layers of annular partitions together.
[0011] Optionally, the diameter of the annular partition decreases sequentially in the direction away from the output end, and the annular partition with the smallest diameter is provided with a mesh structure.
[0012] Optionally, the developing pre-wetting nozzle is positioned 7cm to 14cm directly above the center of the wafer, and the spraying time for deionized water is 4s to 6s; during the process of the developing pre-wetting nozzle spraying deionized water, the wafer rotation speed is 10r / min to 20r / min.
[0013] Optionally, the auxiliary developing nozzle is positioned 4cm to 8cm directly above the center of the wafer, and the spraying time of the developing solution is 2s to 4s; during the spraying of the developing solution by the auxiliary developing nozzle, the wafer rotation speed is increased from 10r / min to 20r / min to 1500r / min to 2000r / min, and the wafer surface is wetted a second time.
[0014] Optionally, in S3, the main developing nozzle spraying developing solution includes the following steps: S31, the main developing nozzle sprays developing solution as it moves radially from the edge of the wafer to the center of the wafer; S32, the main developing nozzle sprays developing solution at the center of the wafer.
[0015] Optionally, the main developing nozzle is positioned 4cm to 8cm above the wafer; in step S31, the main developing nozzle moves radially from the edge of the wafer to the center of the wafer in 6s to 10s, and the wafer rotation speed is 200r / min to 400r / min; in step S32, the main developing nozzle sprays developing solution at the center of the wafer, specifically: the wafer rotation speed is increased to 1000r / min to 1500r / min, and the spraying time is 1s to 2s; then the wafer rotation speed is reduced to 100r / min to 200r / min, and the spraying time is 6s to 10s; finally, the spraying of developing solution is stopped, and the wafer rotation speed is maintained at 100r / min to 200r / min for 10s to 15s, allowing the developing solution and photoresist to react fully.
[0016] In summary, compared with the prior art, the developing method provided by the present invention has at least the following beneficial effects:
[0017] (1) Using a pre-wetting nozzle to uniformly disperse deionized water onto the wafer surface can greatly reduce the influence of deionized water on the surface morphology of photoresist, thereby reducing the generation of blind hole defects in the metal trench pattern and reducing the impact of development residue on the final yield.
[0018] (2) After pre-wetting the wafer and before developing the wafer, a small amount of developer is sprayed with an auxiliary developing nozzle to fully wet the wafer. This not only removes the water barrier layer on the surface of the photoresist and reduces its hydrophobicity, but also effectively enhances the uniformity of the developer covering the wafer surface during the subsequent developing process.
[0019] (3) During the cleaning process, the wafer is rotated at high and low speeds alternately to further remove the developing residues, and inert gas is blown in to further enhance the cleaning effect. Attached Figure Description
[0020] Figure 1 This is a schematic flowchart of the developing method of the present invention;
[0021] Figure 2 This is a schematic diagram of the structure of the developer pre-wetting nozzle of the present invention;
[0022] Figure 3 This is a schematic diagram of the internal structure of the developing and pre-wetting nozzle of the present invention;
[0023] Figure 4 This is a schematic diagram showing the high and low rotation speed distribution during the developing method of the present invention.
[0024] Figure 5 This is a schematic diagram comparing the effects of existing developing methods and the developing method of this invention;
[0025] Explanation of reference numerals in the attached figures:
[0026] 100 Developing and pre-wetting nozzle; 101 Delivery pipe; 102 Annular guide assembly; 103 Flow divider; 104 Connecting mesh; 105 Direction; 121 Annular baffle; 122 Mesh structure; 400 Deionized water. Detailed Implementation
[0027] The following will be combined with the appendix in the embodiments of the present invention. Figure 1 ~Attached Figure 5 The technical solutions, structural features, objectives and effects achieved in the embodiments of the present invention will be described in detail.
[0028] It should be noted that the accompanying drawings are in a very simplified form and use non-precise proportions. They are only used to facilitate and clarify the purpose of illustrating the embodiments of the present invention, and are not intended to limit the implementation conditions of the present invention. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportional relationship, or adjustments to the size should still fall within the scope of the technical content disclosed in the present invention, provided that they do not affect the effects and objectives that the present invention can produce.
[0029] It should be noted that, in this invention, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only the elements expressly listed, but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus.
[0030] like Figure 1 As shown, the present invention provides a developing method, specifically comprising the following steps:
[0031] S1. Deionized water is sprayed onto the wafer surface from multiple angles through a specific developing and pre-wetting nozzle positioned above the wafer, so as to evenly disperse the deionized water onto the wafer surface and reduce the influence of the deionized water on the photoresist morphology, thereby wetting the wafer surface for the first time.
[0032] S2. A small amount of developer is sprayed onto the wafer surface through the auxiliary developing nozzle to reduce the water contact angle of the photoresist surface, reduce the hydrophobicity of the wafer surface, and make the wafer surface wetted a second time.
[0033] S3. Spray developing solution onto the wafer surface through the main developing nozzle, so that the photoresist on the wafer surface reacts with the developing solution;
[0034] S4. Deionized water is sprayed onto the wafer surface through the cleaning nozzle to clean the wafer surface, wash away the developing residue on the wafer surface, complete the entire developing process, and reveal the final developed pattern.
[0035] Furthermore, in step S1, the developing pre-wetting nozzle is positioned 7cm to 14cm directly above the center of the wafer, and the spraying time for deionized water is 4s to 6s; and during the spraying of deionized water by the developing pre-wetting nozzle, the wafer rotation speed is 10r / min to 20r / min. In this process, by spraying deionized water at multiple angles using a relatively low wafer rotation speed, the influence of the deionized water on the photoresist morphology is reduced, and the purpose of uniformly dispersing the deionized water onto the wafer surface is achieved.
[0036] Furthermore, such as Figure 2 and Figure 3 As shown, the developing pre-wetting nozzle 100 includes: a delivery pipe 101 connected to a container storing deionized water for delivering deionized water 400; and an annular guide assembly 102 fixedly connected to the output end of the delivery pipe 101. The annular guide assembly 102 includes several layers of annular baffles 121 spaced apart along the axial direction of the delivery pipe 101 to guide the flow direction of the deionized water 400. The diameter of the annular baffles 121 decreases sequentially along the axial direction 105 of the delivery pipe 101, and the axial direction 105 of the delivery pipe 101 is away from the output end. A grid structure 122 is provided within the annular partition 121 with the smallest diameter to reduce the flow rate of deionized water 400, thereby reducing the impact of deionized water 400 on the photoresist on the wafer surface and thus reducing the influence on the photoresist morphology; a plurality of flow dividers 103 are arranged at intervals along the circumference of the annular partition 121, fixing and connecting adjacent annular partitions 121, and at the same time serving to divide the flow of deionized water 400. The deionized water 400 flowing along the annular partition 121 is dispersed by the flow dividers 103 and evenly distributed on the wafer surface.
[0037] Furthermore, in S2, the auxiliary developing nozzle is positioned 4cm to 8cm directly above the center of the wafer, and the spraying time of the developing solution is 2s to 4s; during the process of the auxiliary developing nozzle spraying the developing solution, the wafer rotation speed is increased from 10r / min to 20r / min to 1500r / min to 2000r / min, and the wafer surface is wetted a second time.
[0038] Furthermore, in step S3, the main developing nozzle is positioned 4cm to 8cm above the wafer. To ensure a more thorough reaction between the wafer surface and the developing solution, the main developing nozzle sprays the developing solution onto the wafer surface in two steps: S31, the main developing nozzle sprays the developing solution as it moves radially from the edge of the wafer to the center of the wafer; S32, the main developing nozzle sprays the developing solution at the center of the wafer.
[0039] Specifically, in S31, the main developing nozzle moves radially from the edge of the wafer to the center of the wafer in a time of 6s to 10s, and the wafer rotation speed is 200r / min to 400r / min. In S32, the main developing nozzle sprays developing solution at the center of the wafer, specifically as follows: the wafer rotation speed is increased to 1000r / min to 1500r / min, and the main developing nozzle sprays developing solution for 1s to 2s; then the wafer rotation speed is reduced to 100r / min to 200r / min, and the main developing nozzle sprays developing solution for 6s to 10s; finally, the main developing nozzle stops spraying developing solution, and the wafer rotation speed is maintained at 100r / min to 200r / min for 10s to 15s, allowing the developing solution and photoresist to react fully.
[0040] Furthermore, in S4, the cleaning nozzle is positioned 5cm to 7cm above the wafer; when it sprays deionized water at the center of the wafer, the wafer rotation speed is 500r / min to 1000r / min, and the spraying time of the deionized water is 15s to 20s; when it moves radially from the center of the wafer to the edge of the wafer, the effect of cleaning the wafer surface can be increased by changing the wafer rotation speed, so as to further reduce the development residue; specifically, when the cleaning nozzle moves radially from the center of the wafer to the edge of the wafer, the wafer rotation speed varies within the range of 1000r / min to 3000r / min, and the spraying time of the deionized water is 30s to 40s.
[0041] In a preferred embodiment of the present invention, such as Figure 4 The diagram shows the high and low rotation speed distribution of the developing method of the present invention. As can be seen from the diagram, when the cleaning nozzle sprays deionized water at the center of the wafer, the wafer rotation speed switches between 500 r / min and 1000 r / min every 3 to 5 seconds. When the cleaning nozzle moves radially along the wafer from the center to the edge, the wafer rotation speed first increases from 500 r / min to 1500 r / min, then increases from 1500 r / min to 2500 r / min within 2 to 3 seconds, and continues to rotate for 8 to 12 seconds, finally decreasing from 2500 r / min to 1000 r / min until cleaning is complete. It can be understood that by continuously changing the wafer rotation speed for cleaning, the cleaning effect can be improved, further reducing developing residues and achieving better developing results.
[0042] Furthermore, it should be noted that the cleaning nozzle is a combined device, which not only has a spray nozzle that can spray deionized water, but also an air jet nozzle that can spray inert gas. Therefore, while the cleaning nozzle sprays deionized water onto the wafer surface through the spray nozzle, it can simultaneously spray nitrogen gas onto the wafer surface through the air jet nozzle, thereby achieving the purpose of improving the cleaning effect.
[0043] like Figure 5 The diagram shows a comparison of the effects of using existing development methods and the development method of the present invention. It can be seen that the existing development method results in blind hole defects due to insufficient development and residue defects due to insufficient cleaning. However, the development method of the present invention, with its optimized process, does not produce blind hole defects or residue defects. Therefore, the development method provided by the present invention optimizes the development process, not only reducing the generation of blind hole defects in metal trench patterns, but also reducing the impact of development residues on the final yield.
[0044] In summary, the developing method provided by this invention uses a pre-wetting developing nozzle to uniformly disperse deionized water onto the wafer surface, which can greatly reduce the influence of deionized water on the surface morphology of photoresist, thereby reducing the generation of blind via defects in the metal trench pattern and reducing the impact of developing residues on the final yield. After pre-wetting the wafer and before developing the wafer, a small amount of developing solution is sprayed with an auxiliary developing nozzle to fully wet the wafer. This not only removes the water-repellent layer on the photoresist surface and reduces its hydrophobicity, but also effectively enhances the uniformity of developing solution coverage on the wafer surface during subsequent developing processes. During the cleaning process, the wafer is rotated alternately at high and low speeds to further remove developing residues, and inert gas blowing further enhances the cleaning effect, making it of great practical value.
[0045] Although the present invention has been described in detail through the preferred embodiments above, it should be understood that the above description should not be considered as a limitation of the present invention. Various modifications and substitutions to the present invention will be apparent to those skilled in the art after reading the above description. Therefore, the scope of protection of the present invention should be defined by the appended claims.
Claims
1. A developing method, characterized in that, Includes the following steps: S1. Deionized water is sprayed onto the wafer surface from multiple angles through a developing and pre-wetting nozzle positioned above the wafer, thus wetting the wafer surface for the first time. S2. Spray developing solution onto the wafer surface through the auxiliary developing nozzle to wet the wafer surface a second time; S3. Spray developing solution onto the wafer surface through the main developing nozzle, so that the photoresist on the wafer surface reacts with the developing solution; S4. Deionized water is sprayed onto the wafer surface through the cleaning nozzle to clean the wafer surface, wash away developing residue, and reveal the developing pattern.
2. The developing method as described in claim 1, characterized in that, In step S4, as the cleaning nozzle moves radially from the center of the wafer to the edge of the wafer, the rotational speed of the wafer is changed to further reduce the development residue.
3. The developing method as described in claim 2, characterized in that, The cleaning nozzle is positioned 5cm to 7cm above the wafer; When the cleaning nozzle sprays deionized water at the center of the wafer, the wafer rotation speed is 500 r / min to 1000 r / min, and the spraying time of the deionized water is 15 s to 20 s. When the cleaning nozzle moves radially from the center of the wafer to the edge of the wafer, the wafer rotation speed varies within the range of 1000 r / min to 3000 r / min, and the spraying time of the deionized water is 30 s to 40 s.
4. The developing method as described in claim 3, characterized in that, The cleaning nozzle sprays deionized water onto the wafer surface and simultaneously injects nitrogen gas onto the wafer surface.
5. The developing method as described in claim 1, characterized in that, The developing pre-wetting nozzle includes a delivery pipe, an annular guide assembly fixedly connected to the output end of the delivery pipe, and several flow dividers; The annular guide assembly includes several layers of annular baffles spaced apart along the axial direction of the conveying pipe; the diverter is spaced apart circumferentially along the annular baffles, and fixes adjacent layers of annular baffles together.
6. The developing method as described in claim 5, characterized in that, The diameter of the annular partition decreases sequentially in the direction away from the output end, and the annular partition with the smallest diameter has a mesh structure inside.
7. The developing method as described in claim 1, characterized in that, The developing pre-wetting nozzle is positioned 7cm to 14cm directly above the center of the wafer, and the spraying time for deionized water is 4s to 6s; during the process of the developing pre-wetting nozzle spraying deionized water, the wafer rotation speed is 10r / min to 20r / min.
8. The developing method as described in claim 1, characterized in that, The auxiliary developing nozzle is positioned 4cm to 8cm directly above the center of the wafer, and the spraying time of the developing solution is 2s to 4s. During the spraying of the developing solution by the auxiliary developing nozzle, the wafer rotation speed is increased from 10r / min to 20r / min to 1500r / min to 2000r / min, and the wafer surface is wetted a second time.
9. The developing method as described in claim 1, characterized in that, In step S3, the main developing nozzle sprays developing solution, which includes the following steps: S31. The main developing nozzle sprays developing solution as it moves radially from the edge of the wafer to the center of the wafer. S32, The main developing nozzle sprays developing solution at the center of the wafer.
10. The developing method as described in claim 9, characterized in that, The main developing nozzle is positioned 4cm to 8cm above the wafer; In S31, the main developing nozzle moves from the edge of the wafer to the center of the wafer along the wafer radial direction for 6s to 10s, and the wafer rotation speed is 200r / min to 400r / min; In step S32, the main developing nozzle sprays developing solution at the center of the wafer, specifically as follows: The wafer rotation speed is increased to 1000r / min~1500r / min, and the spraying time is 1s~2s; The wafer rotation speed was then reduced to 100 r / min to 200 r / min, and the spraying time was 6 s to 10 s; Finally, stop spraying the developer and keep the wafer rotating at 100r / min to 200r / min for 10s to 15s to allow the developer and photoresist to react fully.