Gluing method for improving arrow shadow defect

Abstract

The gluing method for improving the arrow shadow defect comprises the steps that S1, a product sheet before a photoetching process is provided, crystal grains of the product sheet are distributed in rows and columns, and grooves are formed in respective corresponding areas of the crystal grains in every other row; s2, gluing is carried out, a glued sheet is obtained, in the spin coating and uniform glue coating of gluing, a glue solution is dripped to the center position of a dynamic product sheet, after the glue solution is dripped, the product sheet is rotated in at least three steps, the rotating speed of the next step is higher than that of the previous step, and the time of the next step is not shorter than that of the previous step; s3, exposing to obtain an exposed sheet; s4, developing to obtain a developing sheet; and S5, forming a finished product from the display sheet through a subsequent process, testing the finished product, observing a display image of a test end, determining the influence on the arrow shadow defect, and determining optimized parameters and an optimized process of batch production of the photoetching process. Therefore, the arrow shadow defect can be effectively improved, and the yield of finished products is improved.

Description

Technical Field

[0001] This disclosure relates to the semiconductor field, and more specifically to a coating method for improving arrow shadow defects. Background Technology

[0002] Semiconductor products are typically tested at the testing end. The brightness difference in the displayed area is observed on the test end's screen and then transferred back to the wafer to determine if there are radial patterns (i.e., arrow shadows) that match the photoresist spin coating. If arrow shadows are present, the photolithography process needs to be improved to reduce or eliminate them. Summary of the Invention

[0003] In view of the problems existing in the background art, one object of this disclosure is to provide a coating method for improving arrow shadow defects, which can effectively improve arrow shadow defects.

[0004] Therefore, a coating method for improving arrow shadow defects includes the following steps: S1, providing a product wafer before the photolithography process, wherein the grains of the product wafer are distributed in rows and columns, and the grains in every other row have grooves formed in their respective corresponding areas; S2, coating to obtain a coated wafer, wherein, in the spin coating process, a coating solution is dropped onto the center position of the dynamic product wafer, and after the coating solution is dropped, the product wafer is rotated in at least three steps, wherein the rotation speed of the subsequent step is higher than that of the previous step and the time of the subsequent step is not less than that of the previous step; S3, exposure to obtain an exposed wafer; S4, development to obtain a developed wafer; S5, the developed wafer is processed by a subsequent process to form a finished product, the finished product is tested and the display image at the test end is observed to determine the impact on arrow shadow defects and to determine the optimized parameters and optimized processes for mass production of the photolithography process.

[0005] The beneficial effects of this disclosure are as follows: In the coating method for improving arrow shadow defects according to this disclosure, for cases where the grains of the product wafer are distributed in rows and columns and every other row of grains forms grooves in their respective corresponding areas, the coating method involves dripping the adhesive solution onto the center position of the dynamic product wafer during spin coating, rotating the product wafer in at least three steps after the adhesive solution is dripped, with the rotation speed of each subsequent step being higher than that of the previous step and the time of each subsequent step being no less than that of the previous step. By testing the finished product and observing the display image at the test end, the impact on arrow shadow defects can be determined, and the optimized parameters and optimized processes for mass production of the photolithography process can be determined. As verified by the testing process, compared with the case where the adhesive solution is dripped onto the center position of the dynamic product wafer during spin coating and the product wafer is rotated in one step after the adhesive solution is dripped, the coating method for improving arrow shadow defects according to this disclosure can effectively improve arrow shadow defects, thereby improving the yield of the finished product. Attached Figure Description

[0006] Figure 1 This is a schematic diagram of the product sheet before adhesive application.

[0007] Figure 2 It is a schematic diagram of the structural relationship between the photomask, the coating film, and the grains.

[0008] Figure 3 This is the display image of the finished product corresponding to Comparative Example 1 at the test end.

[0009] Figure 4 This is the display image of the finished product corresponding to Example 1 on the test end. Detailed Implementation

[0010] It will be understood that the disclosed embodiments are merely examples of this disclosure, which can be implemented in various forms. Therefore, the specific details disclosed herein should not be construed as limiting, but are intended only as the basis for the claims and as an illustrative basis to teach those skilled in the art how to implement this disclosure in various ways.

[0011] [Glue application method to improve arrow shadow defects] Reference Figure 1 and Figure 2 The adhesive application method for improving arrow shadow defects according to this disclosure includes the following steps: S1 provides a product wafer before the photolithography process. The grains of the product wafer are distributed in rows and columns, and the grains in every other row have grooves formed in their respective regions. S2, applying adhesive to obtain an adhesive sheet, wherein, in the process of applying adhesive by spin coating, adhesive solution is dripped onto the center of the dynamic product sheet, and after the adhesive solution is dripped, the product sheet is rotated in at least three steps, wherein the rotation speed of the subsequent step is higher than that of the previous step and the time of the subsequent step is not less than that of the previous step. S3, Exposure, to obtain the exposed film; S4, development, to obtain the film; S5, the film is processed into a finished product through subsequent processes. The finished product is tested and the displayed image at the test end is observed to determine the impact on the arrow shadow defect and to determine the optimized parameters and optimized process for mass production of the photolithography process.

[0012] In the coating method for improving arrow shadow defects according to this disclosure, for a product wafer where the grains are distributed in rows and columns and every other row of grains has a groove in its corresponding region, the method involves dripping the adhesive solution onto the center of a dynamic product wafer during spin coating, rotating the product wafer in at least three steps after the adhesive solution has been dripped, with each subsequent step having a higher rotation speed and a duration not less than the previous step. By testing the finished product and observing the displayed image at the test end, the impact on arrow shadow defects is determined, and optimized parameters and processes for mass production in the photolithography process are identified. As verified by the testing process, compared to the method of dripping the adhesive solution onto the center of a dynamic product wafer during spin coating and then rotating the product wafer in one step after the adhesive solution has been dripped, the coating method for improving arrow shadow defects according to this disclosure effectively improves arrow shadow defects, thereby increasing the product yield.

[0013] In step S1, in one example, the product wafer is an 8-inch diameter wafer with a 150 Å thick SIN film coating on its surface. However, this is not the only possibility; the surface condition and size of the product wafer can vary depending on actual production requirements. Furthermore, various functional layers may be present beneath the SIN film, depending on the product requirements.

[0014] In step S1, in one example, each groove has a depth of 2.5 μm, a length of 60 μm, and a width of 20 μm. However, this is not the only limitation; the dimensions of each groove can be determined based on the specific design requirements of the product wafer. Furthermore, the position of each groove within the die is not limited to the lower left corner shown in the figure; it can be positioned according to the spatial layout of the pattern within the die.

[0015] In one example, step S2, the coating process, includes the following sub-steps: S21, HMDS film formation, where an HMDS film is formed on the surface of the product sheet using a vapor phase method; S22, pre-coating cooling, where the product sheet with the HMDS film on its surface is cooled in a cooling bath to the temperature required for coating; S23, coating, where the product sheet is spin-coated in a coating process tank, wherein the spin-coating process is the same as described above; and S24, pre-baking, where the product sheet after spin-coating is pre-baked in a pre-baking process tank. Specifically, in one example, in sub-step S21, the operation of forming the HMDS film using a vapor phase method is as follows: the product sheet is placed on a stage in a vacuum chamber and the stage is heated to 110°C. Nitrogen is used as the carrier gas at a pressure of 25 kPa. HMDS vapor carried by nitrogen is introduced, the pressure in the vacuum chamber is maintained at 20 Pa, the HMDS vapor carried by nitrogen is introduced for 60 s, and the thickness of the formed HMDS film is 6 Å. Specifically, in one example, the temperature required for uniform coating in sub-step S22 is 23°C. Specifically, in one example, in sub-step S23, the adhesive type is DHK-BF511, and the spin coating process is as follows: 1.5 mL of adhesive solution is dropped onto the center of the product sheet at a dynamic speed of 2500 rpm. After the adhesive solution has been dropped for 2 seconds, the product sheet is rotated in three steps: first, at 500 rpm for 1.5 seconds; second, at 1000 rpm for 1.5 seconds; and third, at 2000 rpm for 2 seconds. The final coating thickness is 4700 Å. Specifically, in one example, in sub-step S24, the pre-baking temperature is 90°C, and the time is 60 seconds.

[0016] In one example, step S3, exposure, includes the following sub-steps: S31, pre-exposure cooling, where the pre-baked coated film is cooled in a cooling bath to the required exposure temperature of 23°C; S32, exposure, using a VOT612-010-BE template with a layout design linewidth of 290±20nm and a Nikon S205C step-scan exposure system, with a step X direction step of 12949μm and a Y direction step of 250389μm, and an exposure dose of 22mJ / cm² for each step-scan exposure. 2 The imaging focal length is 0.1μm and the NA value is 0.68; S33, post-exposure baking, post-exposure baking is carried out in the post-exposure baking process tank, the temperature of post-exposure baking is 110℃ and the time is 120s.

[0017] In one example, the development step S4 includes the following sub-steps: S41, pre-development cooling, where the exposed film baked after exposure is cooled in a cooling tank to the temperature of 23°C required for development; S42, development, where the pre-development cooled exposed film is placed on the turntable of the developing machine, and while rotating, developer is dripped onto the center of the exposed film, followed by rinsing with water while rotating. The rotation is unidirectional, the rotation speed is 2000 rpm, positive photoresist developer is used, the developer type is ZX-238, the development time is 60s, and the rinsing time is 30s; S43, post-baking in a post-baking process tank, the post-baking temperature is 110°C, and the time is 90s.

[0018] [test] Example 1 Example 1 uses the following steps: S1 provides a product wafer before the photolithography process. The wafer's dies are arranged in rows and columns, and every other row of dies has a groove in its corresponding area. The product wafer is an 8-inch diameter wafer with a 150Å thick SIN film layer on its surface. Each groove is 2.5μm deep, 60μm long, and 20μm wide. The groove is located in the lower left corner of the die. S2, Apply adhesive to obtain an adhesive-coated sheet. The adhesive application in step S2 is performed using the following sub-steps: S21, HMDS film formation: An HMDS film is formed on the surface of the product sheet using a vapor phase method. The operation of forming the HMDS film using the vapor phase method is as follows: the product sheet is placed on the stage of the vacuum chamber and the stage is heated to 110°C. Nitrogen is used as the carrier gas and the pressure of the nitrogen is 25 kPa. HMDS vapor carried by nitrogen is introduced. The pressure of the vacuum chamber is maintained at 20 Pa. The time for introducing HMDS vapor carried by nitrogen is 60 s. The thickness of the formed HMDS film is 6 Å. S22, Cooling before spin coating: The product sheet with HMDS film formed on the surface is cooled in a cooling bath to the temperature required for spin coating, wherein the temperature required for spin coating is 23°C. S23, Coating: The product sheet is spin-coated in a spin coating process tank. The adhesive type is DHK-BF511. The spin coating process is as follows: 1.5 mL of adhesive solution is dropped onto the center of the product sheet at a dynamic speed of 2500 rpm. After the adhesive solution is dropped for 2 seconds, the product sheet is rotated in three steps: first, the product sheet is rotated at 500 rpm for 1.5 seconds; second, the product sheet is rotated at 1000 rpm for 1.5 seconds; and third, the product sheet is rotated at 2000 rpm for 2 seconds. The final coating thickness is 4700 Å. S24, Pre-baking: The product sheet after spin coating is pre-baked in the pre-baking process tank, where the pre-baking temperature is 90℃ and the time is 60s. S3, exposure, obtaining the exposure film. The exposure in step S3 is performed using the following sub-steps: S31, pre-exposure cooling: the coated sheet after pre-baking is cooled in a cooling bath to the temperature of 23°C required for exposure. S32, exposure, using VOT612-010-BE template with a layout design linewidth of 290±20nm and a Nikon S205C machine for step-scan exposure. The stepping X direction is 12949μm, the stepping Y direction is 250389μm, and the exposure dose per step-scan exposure is 22mj / cm. 2 The imaging focal length is 0.1 μm and the NA value is 0.68; S33, Post-exposure baking, Post-exposure baking is carried out in the post-exposure baking process tank at a temperature of 110℃ for 120s; S4, development, to obtain the film. The development step S4 comprises the following sub-steps: S41, pre-development cooling: The exposed film baked after exposure is cooled in a cooling bath to the temperature required for development, 23°C. S42, Development: Place the cooled film on the turntable of the developing machine. While rotating, drip developer onto the center of the film. Then, while rotating, rinse with water. The rotation is unidirectional and the rotation speed is 2000 rpm. Positive photoresist developer is used. The developer type is ZX-238. The development time is 60 seconds and the rinsing time is 30 seconds. S43, post-drying in the post-drying process tank, the post-drying temperature is 110℃ and the time is 90s; S5, the film is processed into a finished product through subsequent processes. The finished product is tested and the displayed image at the test end is observed to determine the impact on the arrow shadow defect and to determine the optimized parameters and optimized process for mass production of the photolithography process.

[0019] Comparative Example 1 Except for replacing "rotate the product sheet in three steps, first step 500 rpm for 1.5s, second step 1000 rpm for 1.5s, third step 2000 rpm for 2s" in sub-step S23 of step S2 in Example 1 with "rotate the product sheet in one step, the first step is 2000 rpm for 5s", the rest is the same as in Example 1.

[0020] Figure 3 This is the display image of the finished product corresponding to Comparative Example 1 at the test end. Figure 4 This is a display image of the finished product corresponding to Example 1 at the test end. For the case where the grain area has grooves, Figure 3The corresponding spin coating process involves dripping adhesive solution onto the center of a dynamic product sheet during the spin coating process, followed by a one-step rotation of the product sheet after the adhesive solution has finished dripping. Figure 4 The corresponding spin coating process involves dripping adhesive solution onto the center of a dynamic product sheet during the spin coating process. After the adhesive solution is dripped, the product sheet is rotated in three steps, with the rotation speed of each subsequent step being higher than that of the previous step and the time of each subsequent step being no less than that of the previous step.

[0021] Comparison Figure 3 and Figure 4 , Figure 3 The finished product has obvious arrow shadows, while Figure 4 The arrow-like patterns on the finished product were significantly reduced. The inventors believe that the arrow-like patterns are mainly caused by the centrifugal effect during spin coating. The centrifugal force gradient causes more adhesive solution to be ejected from the edges of the product sheet. Since the grain region has grooves, these grooves interfere with the centrifugal force gradient (causing a shear shift in the adhesive solution at the groove edges), similar to the turbulence caused by fluid instability when a fluid passes over an obstacle in fluid mechanics. This interference is more pronounced at high spin-coating speeds. Example 1 uses a three-step spin-coating process, with each step gradually increasing the spin speed and maintaining the same time duration. The final step reaches the high speed of the one-step spin-coating process in Comparative Example 1 (but the final step's time is shorter than the one-step spin-coating time in Comparative Example 1 because Example 1 uses a three-step spin-coating process). This reduces the shear shift in the adhesive solution at the groove edges, thus significantly reducing the arrow-like patterns in Example 1.

[0022] Several exemplary embodiments have been described in detail above, but this document is not intended to limit itself to the explicitly disclosed combinations. Therefore, unless otherwise stated, the various features disclosed herein can be combined to form several other combinations, which are not shown for simplicity.

Claims

1. A method for applying adhesive to improve arrow shadow defects, characterized in that, Including the following steps: S1 provides a product wafer before the photolithography process. The grains of the product wafer are distributed in rows and columns, and the grains in every other row have grooves formed in their respective areas. S2, applying adhesive to obtain an adhesive sheet, wherein, in the process of applying adhesive by spin coating, adhesive solution is dripped onto the center of the dynamic product sheet, and after the adhesive solution is dripped, the product sheet is rotated in at least three steps, wherein the rotation speed of the subsequent step is higher than that of the previous step and the time of the subsequent step is not less than that of the previous step. S3, Exposure, to obtain the exposed film; S4, development, to obtain the film; S5, the film is processed into a finished product through subsequent processes. The finished product is tested and the displayed image at the test end is observed to determine the impact on the arrow shadow defect and to determine the optimized parameters and optimized process for mass production of the photolithography process.

2. The adhesive application method for improving arrow shadow defects according to claim 1, characterized in that, In step S1, The product is an 8-inch diameter wafer with a 150Å thick SIN film coating on its surface; Each groove has a depth of 2.5 μm, a length of 60 μm, and a width of 20 μm.

3. The adhesive application method for improving arrow shadow defects according to claim 2, characterized in that, Step S2, applying adhesive, includes the following sub-steps: S21, HMDS film formation, using a vapor phase method to form an HMDS film on the surface of the product sheet; S22, Cooling before spin coating: The product sheet with an HMDS film formed on its surface is cooled in a cooling bath to the temperature required for spin coating. S23, Coating: The product sheet is coated with a uniform adhesive in a spin coating process tank, wherein the spin coating is performed using the aforementioned spin coating method. S24, Pre-baking: The product sheet after spin coating is pre-baked in the pre-baking process tank.

4. The adhesive application method for improving arrow shadow defects according to claim 3, characterized in that, In sub-step S21, the operation of forming HMDS film by gas phase is as follows: the product sheet is placed on the stage of the vacuum chamber and the stage is heated to 110°C. Nitrogen is used as the carrier gas and the pressure of nitrogen is 25 kPa. HMDS vapor carried by nitrogen is introduced. The pressure of the vacuum chamber is maintained at 20 Pa and the time for introducing HMDS vapor carried by nitrogen is 60 s. The thickness of the formed HMDS film is 6 Å.

5. The adhesive application method for improving arrow shadow defects according to claim 3, characterized in that, In sub-step S22, the temperature required for homogenization is 23°C.

6. The adhesive application method for improving arrow shadow defects according to claim 3, characterized in that, In sub-step S23, The adhesive's model number is DHK-BF511. The spin coating process is as follows: 1.5 mL of adhesive solution is dropped onto the center of the product sheet at a dynamic speed of 2500 rpm. After the adhesive solution is dropped for 2 seconds, the product sheet is rotated in three steps: first, the product sheet is rotated at 500 rpm for 1.5 seconds; second, the product sheet is rotated at 1000 rpm for 1.5 seconds; and third, the product sheet is rotated at 2000 rpm for 2 seconds. The final coating thickness is 4700 Å.

7. The adhesive application method for improving arrow shadow defects according to claim 3, characterized in that, In sub-step S24, the pre-baking temperature is 90°C and the time is 60 seconds.

8. The adhesive application method for improving arrow shadow defects according to claim 3, characterized in that, The exposure in step S3 includes the following sub-steps: S31, pre-exposure cooling: the coated sheet after pre-baking is cooled in a cooling bath to the temperature of 23°C required for exposure. S32, exposure, using VOT612-010-BE template with a layout design linewidth of 290±20nm and a Nikon S205C machine for step-scan exposure. The stepping X direction is 12949μm, the stepping Y direction is 250389μm, and the exposure dose per step-scan exposure is 22mj / cm. 2 The imaging focal length is 0.1 μm and the NA value is 0.68; S33, Post-exposure baking: Post-exposure baking is performed in a post-exposure baking process tank at a temperature of 110℃ for 120 seconds.

9. The adhesive application method for improving arrow shadow defects according to claim 8, characterized in that, The development step S4 includes the following sub-steps: S41, pre-development cooling: The exposed film baked after exposure is cooled in a cooling bath to the temperature required for development, 23°C. S42, Development: Place the cooled film on the turntable of the developing machine. While rotating, drip developer onto the center of the film. Then, while rotating, rinse with water. The rotation is unidirectional and the rotation speed is 2000 rpm. Positive photoresist developer is used. The developer type is ZX-238. The development time is 60 seconds and the rinsing time is 30 seconds. S43, post-drying in the post-drying process tank, the post-drying temperature is 110℃ and the time is 90s.

Images