Substrate cleaning system and substrate cleaning method

Abstract

The present invention discloses a substrate cleaning system, comprising a chamber, a support chuck disposed within the chamber, and a spray unit, wherein the substrate is fixed to the support chuck; the spray unit is used to spray a rinsing liquid onto the substrate to clean the substrate, wherein the spray unit includes a nozzle, wherein a plurality of discharge pipes are disposed in an outwardly inclined structure, so that the rinsing liquid discharged through the discharge pipes is evenly sprayed onto the surface of the substrate. The present invention uses a retractable baffle to receive the rinsing liquid after rinsing when the support chuck is not rotating, and allows it to flow into a discharge layer for processing; the nozzle is designed with concentric circular holes / shower holes at different angles to ensure that liquid flows through the entire substrate; when the chuck is not rotating, the liquid flow lacks outward force, so a rotating nozzle arm is designed to provide an outward force for the liquid flow.

Description

Technical Field

[0001] The present invention relates to the technical field of wafer manufacturing, and in particular to a substrate cleaning system and a substrate cleaning method. Background Art

[0002] In the manufacturing of integrated circuits, a relatively large silicon substrate (also called a wafer) undergoes numerous separate processing steps to form multiple individual integrated circuits on its surface. The steps used to form these integrated circuits can be of various types, including masking, etching, deposition, diffusion, ion implantation, and polishing, among many others. Typically, between each of these process steps, the wafer undergoes a cleaning step. These cleaning steps help protect the integrated circuits from contaminants that could cause harmful defects within the delicate structures of the integrated circuits.

[0003] Figure 1 The figure shows a typical schematic diagram of a substrate cleaning system using wet cleaning in the prior art. Figure 1 As shown, the chamber includes a chuck 10 (which supports and rotates the wafer, providing centrifugal force to disperse chemicals on the wafer at a speed of 300 to 2000 rpm), multiple drainage layers 21, 22, and 23 (different layers are used to recover or discharge different chemicals, with each layer having a fixed, non-retractable baffle at each end), a guide arm 30 (which supplies chemicals to the wafer surface and can be configured to oscillate back and forth across the wafer or remain stationary at the center of the wafer), and a nozzle 40 (the sole outlet for the chemicals). In the final step of the BEOL wet cleaning process, a solvent (such as DIW) is used to remove residues from the previous step. However, during the cleaning process, static electricity can easily accumulate on the wafer surface. When using DIW to clean the wafer surface, on the one hand, DIW has low conductivity, making it difficult to dissipate static electricity during rinsing. On the other hand, static electricity generated by friction during the rinsing process accumulates on the wafer surface. This static electricity can easily damage certain functional structures containing metal materials, such as copper, within the integrated circuit.

[0004] The current method to remove static electricity is to add additives to improve conductivity. For example, DICO2 / diluted-NH4OH can effectively remove static electricity, but the additives will react with Cu and produce additional corrosion. Summary of the Invention

[0005] An object of the present invention is to provide a substrate cleaning system and a substrate cleaning method.

[0006] The technical solution adopted by the present invention is: constructing a substrate cleaning system, including a chamber and a support chuck and a spray unit arranged in the chamber, the substrate is fixed on the support chuck; the spray unit is used to spray a rinsing liquid onto the substrate to clean the substrate, wherein the spray unit includes a nozzle, and a plurality of discharge pipes configured in an outwardly inclined structure are provided in the nozzle, so that the rinsing liquid discharged through the discharge pipes can be evenly sprayed onto the surface of the substrate.

[0007] In the substrate cleaning system provided by the present invention, the nozzle is configured to be rotatable.

[0008] In the substrate cleaning system provided by the present invention, a nozzle opening is provided in the nozzle, the multiple exhaust pipes are connected to the nozzle opening and extend obliquely downward from the nozzle opening toward the support chuck, and the lower ends of the multiple exhaust pipes form multiple spray holes in the same plane.

[0009] In the substrate cleaning system provided by the present invention, the spray hole is at least one of a circular hole, an arc hole, a square hole, a triangular hole or a polygonal hole.

[0010] In the substrate cleaning system provided by the present invention, the nozzle is provided with a first fluid channel, and the multiple exhaust pipes are arranged at different heights along the axial direction of the first fluid channel, and / or the multiple exhaust pipes are arranged at the periphery of the same height surrounding the first fluid channel.

[0011] In the substrate cleaning system provided by the present invention, the length of the exhaust pipe gradually decreases from top to bottom along the axial direction of the first fluid channel.

[0012] In the substrate cleaning system provided by the present invention, the spray unit further includes a nozzle arm, which is provided with a second fluid channel, the upper portion of which is connected to an external flushing liquid pipe, and the lower portion of which is connected to the nozzle.

[0013] In the substrate cleaning system provided by the present invention, the supporting chuck is configured to be fixed and non-rotatable.

[0014] In the substrate cleaning system provided by the present invention, a plurality of drainage layers are arranged at different heights along the inner wall of the chamber to guide the rinsing liquid sprayed on the surface of the substrate out of the chamber; the drainage layer is connected to a retractable baffle; the support chuck is provided with an opening connected to the retractable baffle, and the support chuck can be moved vertically up and down in the chamber to a preset height and be engaged with the corresponding baffle to realize different processes for cleaning the substrate.

[0015] According to another aspect of the present invention, there is also provided a method for cleaning a substrate using the substrate cleaning system as described above, comprising the following steps:

[0016] Controlling the support chuck to rise and fall to a height corresponding to the flushing liquid discharge layer, and keeping the support chuck stationary;

[0017] Controlling the baffle corresponding to the flushing liquid discharge layer to extend to abut against the opening of the support chuck;

[0018] Control the nozzle arm to move to the center of the substrate;

[0019] spraying a rinse liquid onto the substrate surface through a nozzle;

[0020] When the flushing process is finished, the baffle corresponding to the flushing liquid discharge port is controlled to retract to its original length.

[0021] The substrate cleaning system and substrate cleaning method of the present invention have the following beneficial effects: in the substrate cleaning system provided by the present invention, the support chuck is configured to be non-rotatable, which can reduce the static electricity generated by the friction between the rinsing chemicals and the substrate surface, and the rinsing liquid after rinsing is received by a retractable baffle when the support chuck is not rotating, and flows into the discharge layer for processing; the new nozzle is designed to form multiple spray holes in the same plane or to set multiple spray holes at different heights to supply chemicals, thereby ensuring that liquid flows through the entire substrate; when the chuck is not rotating, the liquid flow lacks outward force, so the nozzle arm is designed to rotate to provide outward force for the liquid flow. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only embodiments of the present invention. Those skilled in the art can also derive other drawings based on the provided drawings without inventive work.

[0023] Figure 1 FIG. 1 is a schematic diagram showing a typical composition of a substrate cleaning system using wet cleaning in the prior art;

[0024] Figure 2 FIG2 is a schematic diagram showing a typical structure of a substrate cleaning system provided by an embodiment of the present invention;

[0025] Figure 3 (a)-(c) are schematic diagrams of a nozzle unit provided in one embodiment of the present invention;

[0026] Figure 4 (a)-(c) are schematic diagrams of a nozzle unit provided in another embodiment of the present invention;

[0027] Figure 5The present invention is a flow chart of a method for cleaning a substrate using the substrate cleaning system provided by the present invention. DETAILED DESCRIPTION

[0028] In the following description, numerous specific details are provided to provide a more thorough understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention may be practiced without one or more of these details. In other instances, certain technical features well known in the art are not described to avoid confusion with the present invention.

[0029] It should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of the stated features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0030] As mentioned above, the amount of static electricity accumulated on the surface of the DIW flowing over the wafer is related to the wafer's rotational speed. Considering that current single-wafer wet cleaning tools can only process while the wafer is rotating, static electricity accumulation can be significantly reduced at low rotational speeds. The present invention provides a substrate cleaning system that can effectively rinse the wafer surface and significantly reduce static electricity accumulation without requiring wafer rotation.

[0031] Figure 2 FIG. 1 is a schematic diagram showing a typical structure of a substrate cleaning system provided by an embodiment of the present invention. Figure 2 As shown, the substrate cleaning system provided by the present invention includes a chamber, a support chuck 210 disposed within the chamber, and a spray unit. The substrate is fixed to the support chuck 210. The support chuck 210 moves vertically along the chamber to stop at different heights and clean the substrate using different processes. The spray unit is used to spray a rinsing liquid onto the substrate to clean it. The spray unit includes a nozzle 220 and a nozzle arm 230. The nozzle 220 is provided with multiple discharge pipes arranged in an outwardly inclined structure so that the rinsing liquid discharged through the discharge pipes is evenly sprayed onto the surface of the substrate. The support chuck is configured to be non-rotatable.

[0032] Specifically, in one embodiment of the present invention, multiple drainage layers 240 are arranged at different heights along the inner wall of the chamber to direct the rinse liquid sprayed on the substrate surface out of the chamber. Each drainage layer is connected to a retractable baffle 2401 on either side. The support chuck has openings that engage with the retractable baffles. When the support chuck is not rotating, the baffles extend to engage with the openings. The support chuck can move vertically up and down within the chamber to a predetermined height, engaging with corresponding baffles to facilitate different substrate cleaning processes. When the support chuck is engaged with the baffles through the openings, chemicals flowing from the chuck flow toward the baffles and out of the chamber. During vertical movement of the chuck, the baffles at different levels maintain the same length. During substrate cleaning, rotation of the support chuck enhances cleaning efficiency. The cleaning liquid is dispersed into the drainage layers for processing due to the centrifugal force generated by the rotation, eliminating the need for the baffles to extend. During DIW rinsing, the static position of the support chuck significantly reduces static electricity generated during the DIW rinsing process. Therefore, the retractable baffle receives the rinse liquid after rinsing while the support chuck is not rotating, and allows it to flow into the discharge layer for processing.

[0033] Specifically, in one embodiment of the present invention, the nozzle is configured to be rotatable, and the nozzle arm is rotatable. In the present invention, the nozzle arm can rotate at a fixed point to increase the outward centrifugal force of the liquid flow.

[0034] Figure 3 (a)-(c) are schematic diagrams of a nozzle unit provided by an embodiment of the present invention. Figure 3 As shown in (a), a second fluid channel 2310 is provided in the nozzle arm 230, the upper part of the second fluid channel is connected to the external rinsing liquid pipeline, and the lower part of the second fluid channel is connected to the nozzle. A nozzle opening 2340 is provided on the top of the nozzle, and the multiple discharge pipes 2320 are connected from the nozzle opening 2340 and extend obliquely downward from the nozzle opening 2340 toward the support chuck, and the lower ends of the multiple discharge pipes form multiple spray holes 2330 in the same plane. The spray hole is at least one of a circular hole, an arc hole, a square hole, a triangular hole or a polygonal hole. Since it is impossible to ensure that the rinsing liquid can be sprayed to all substrates when the support chuck is not rotating, a new nozzle unit is designed in the present invention, which has multiple outlet ends at different angles. When the nozzle arm is moved to a fixed point for processing, it is ensured that the entire surface of the substrate can be sprayed with the rinsing liquid. The shape of the nozzle is designed to be in the form of a shower head, and the shape of the hole at its bottom can be concentric circles ( Figure 3 (b)) or has many holes ( Figure 3 (c)). The hole angle design varies depending on the hole concentric circles or hole spraying, which can expand the substrate cleaning area.

[0035] Figure 4 (a)-(c) are schematic diagrams of a nozzle unit provided by another embodiment of the present invention. Figure 4 As shown in (a)-(c), the nozzle 220 includes an upper half 2210 and a lower half 2220, and the nozzle is provided with a first fluid channel 2350, which runs through the upper half and the lower half, and the multiple discharge pipes are arranged at different heights along the axial direction of the first fluid channel 2350, and / or the multiple discharge pipes are arranged on the periphery of the same height surrounding the first fluid channel; the length of the discharge pipe gradually decreases from top to bottom along the axial direction of the first fluid channel, and the lower ends of the multiple discharge pipes form a plurality of spray holes 2330 on the side wall of the lower half.

[0036] In the substrate cleaning system provided by this invention, the support chuck is designed to remain stationary to reduce static electricity generated by friction between the rinse chemicals and the substrate surface. A novel nozzle design features concentric circular holes / shower holes at varying angles to supply the chemicals, ensuring liquid flow across the entire substrate. When the chuck is stationary, the liquid flow lacks outward force, so a rotating nozzle arm is designed to provide this outward force.

[0037] Figure 5 The present invention provides a method for cleaning a substrate using the substrate cleaning system, which includes the following steps:

[0038] Step S1, controlling the support chuck to rise and fall to a height corresponding to the flushing liquid discharge layer, and keeping the support chuck stationary and non-rotating;

[0039] Step S2, controlling the baffle corresponding to the flushing liquid discharge layer to extend until it abuts against the opening of the support chuck;

[0040] Step S3, controlling the nozzle arm to move to the center of the substrate;

[0041] Step S4, spraying a rinse liquid onto the surface of the substrate through a nozzle;

[0042] Step S5: When the flushing process is finished, the baffle corresponding to the flushing liquid discharge layer is controlled to retract to its original length.

[0043] The present invention has been described through the above-described embodiments. However, it should be understood that the above-described embodiments are for illustrative and illustrative purposes only and are not intended to limit the present invention to the described embodiments. Furthermore, it will be understood by those skilled in the art that the present invention is not limited to the above-described embodiments and that various variations and modifications may be made based on the teachings of the present invention, all of which fall within the scope of the present invention. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A substrate cleaning system, characterized in that: The cleaning system of claim 1, wherein the cleaning agent is a liquid having a first and a second pressure relief device, wherein the cleaning agent is a liquid having a first and a second pressure relief device, and the cleaning agent is a liquid having a first and a second pressure relief device, wherein the cleaning agent is a liquid having a first and a second pressure relief device, and wherein the cleaning agent is a liquid having a first and a second pressure relief device, and wherein the cleaning agent is a liquid having a first and a second pressure relief device, and wherein the cleaning agent is a liquid having a first and a second pressure relief device, and wherein the cleaning agent is a liquid having a first and a second pressure relief device, and wherein the cleaning agent is a liquid having a first and a second pressure relief device, 2. The substrate cleaning system according to claim 1, wherein: The nozzle is configured to be rotatable.

3. The substrate cleaning system according to claim 1 or 2, wherein: The nozzle is provided with a nozzle opening, the plurality of discharge pipes are connected to the nozzle opening and extend obliquely downward from the nozzle opening toward the support chuck, and the lower ends of the plurality of discharge pipes form a plurality of spray holes in the same plane.

4. The substrate cleaning system according to claim 3, wherein: The spray hole is at least one of a circular hole, an arc hole, a square hole, a triangular hole or a polygonal hole.

5. The substrate cleaning system according to claim 1 or 2, wherein: The nozzle is provided with a first fluid channel, and the plurality of discharge pipes are arranged at different heights along the axial direction of the first fluid channel, and / or the plurality of discharge pipes are arranged at a periphery at the same height surrounding the first fluid channel.

6. The substrate cleaning system according to claim 5, wherein: The length of the discharge pipe gradually decreases from top to bottom along the axial direction of the first fluid channel.

7. The substrate cleaning system according to claim 1 or 2, characterized in that: The spray unit further includes a nozzle arm, wherein the nozzle arm is provided with a second fluid channel, the upper portion of the second fluid channel is connected to the external flushing liquid pipe, and the lower portion of the second fluid channel is connected to the nozzle.

8. The substrate cleaning system according to claim 1, wherein: The support chuck is configured to be fixed against rotation.

9. A method for cleaning a substrate using a substrate cleaning system according to any one of claims 1 to 8, characterized in that: The following steps are involved: Control the support chuck to rise and fall to a height corresponding to the flushing liquid discharge layer, and keep the support chuck stationary and non-rotating; Controlling the baffle corresponding to the flushing liquid discharge layer to extend to abut against the opening of the support chuck; Control the nozzle arm to move to the center of the substrate; spraying a rinse liquid onto the substrate surface through a nozzle; When the flushing process is finished, the baffle corresponding to the flushing liquid discharge layer is controlled to retract to its original length.

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