A back-washable semiconductor chuck and a cleaning method

Abstract

This application relates to a back-washable semiconductor chuck and a cleaning method. The semiconductor chuck includes a chuck body, support pins, clamping pins, and a back-washing assembly. The chuck body is used to hold a wafer. A plurality of support pins are spaced apart along the edge of the chuck body, and the plurality of support pins cooperate with each other to support the wafer. A plurality of clamping pins are spaced apart along the edge of the chuck body, and the plurality of clamping pins cooperate with each other to clamp the wafer. The back-washing assembly is located at the center of the chuck body and is used to perform back-side cleaning and drying of the wafer while the front side of the wafer is being cleaned and dried. By setting the back-washing assembly at the center of the chuck body, the limitation of the original chuck, which only has the function of supporting and fixing, is overcome. It realizes that while the front side of the wafer is being cleaned and dried, the back side of the wafer is being cleaned and dried simultaneously using the back-washing assembly, which directly solves the problem of residue after the chemical solution seeps into the back side from a physical level.

Description

Technical Field

[0001] This invention relates to the field of semiconductor manufacturing technology, and more specifically to a back-washable semiconductor chuck and a cleaning method thereon. Background Technology

[0002] In the single-wafer aluminum wet etching process of semiconductor manufacturing, Bernoulli chucks are typically used to support and hold the wafer. However, in actual production, due to the viscosity and surface tension of the aluminum etching solution, when etching the front side of the wafer, the solution easily penetrates and climbs along the wafer edge to the back side. Existing Bernoulli chucks have a simple structure, and during rinsing and drying processes, they can only treat the front side of the wafer, failing to effectively clean the back side. Even attempts to increase the chuck speed to increase centrifugal force or to increase the Bernoulli air volume to blow away residual solution cannot completely remove the clumps of solution residue accumulated on the back side of the wafer. These residues form stains during subsequent drying, which not only contaminate the wafer transport robot but may also lead to a decrease in product yield, posing a serious quality risk. Summary of the Invention

[0003] The purpose of this invention is to provide a back-washable semiconductor chuck and a cleaning method. By setting a back-washing component at the center of the chuck body, it overcomes the limitation of the original chuck which only has a supporting and fixing function. It enables simultaneous cleaning and drying of the back side of the wafer while cleaning and drying the front side, directly solving the problem of residual chemicals after seeping to the back side from a physical perspective. Through active back-side fluid flushing and gas removal, it replaces the inefficient method of passive centrifugal force removal, which can thoroughly remove residual liquid from the back side of the wafer and avoid the formation of dirt spots. At the same time, since the back side cleaning and front side cleaning are carried out simultaneously, the wafer cleanliness is significantly improved and the production quality is guaranteed, without affecting the output efficiency of the single-wafer process.

[0004] To achieve the above objectives, according to a first aspect of the present invention, a washable semiconductor chuck is provided, comprising: The chuck body, used to hold the wafer; A plurality of support pins are spaced apart along the edge of the chuck body, and the plurality of support pins cooperate with each other to support the wafer; A plurality of clamping pins are spaced apart along the edge of the chuck body, and the plurality of clamping pins cooperate with each other to clamp the wafer; The back-wash assembly is located at the center of the chuck body and is used to perform back-wash and dry operations on the wafer while the front side of the wafer is being cleaned and dried.

[0005] Optionally, the backwash assembly includes: An installation block is embedded in the center of the chuck body. A water outlet and an air outlet are provided in the center of the installation block. The water outlet is connected to the water outlet pipe of the external rinsing robotic arm, and the air outlet is connected to the air outlet pipe of the external rinsing robotic arm.

[0006] Optionally, the diameter of the support PIN gradually decreases from one end connected to the chuck body to the other.

[0007] Optionally, the chuck body is provided with a plurality of support seats corresponding to the clamping PIN, and each clamping PIN is disposed on the corresponding support seat.

[0008] Optionally, the diameter of the clamping PIN is 2mm-3mm.

[0009] According to a second aspect of the present invention, a method for cleaning a semiconductor chuck is provided, comprising the following steps: After the etching process is completed, the front side of the wafer is cleaned; While the front side of the wafer is being cleaned, the back side of the wafer is being cleaned simultaneously using the back cleaning assembly.

[0010] Optionally, the step of cleaning the front side of the wafer after the etching process is completed includes the following steps: Rinse the front side of the wafer with pure water; After rinsing with pure water, the front side of the wafer is dried with nitrogen.

[0011] Optionally, while cleaning the front side of the wafer, the back side of the wafer is simultaneously cleaned by the back cleaning assembly, including the following steps: While rinsing the front side of the wafer with pure water, the back side of the wafer is simultaneously rinsed with pure water to remove residual liquid from the back side of the wafer. While the front side of the wafer is being dried with nitrogen, the back side of the wafer is also being dried with nitrogen simultaneously.

[0012] The beneficial effects of this invention are as follows: By setting a back-washing component at the center of the chuck body, the limitation of the original chuck having only a supporting and fixing function is changed. It realizes that while cleaning and drying the front side of the wafer, the back side of the wafer is cleaned and dried simultaneously using the back-washing component. This directly solves the problem of residual liquid after the liquid seeps into the back side from a physical level. Through active back-side fluid flushing and gas removal, it replaces the inefficient method of passively relying on centrifugal force to remove the liquid, which can thoroughly remove residual liquid on the back side of the wafer and avoid the generation of dirt spots. At the same time, since the back-side cleaning and front-side cleaning are carried out simultaneously, the wafer cleanliness is significantly improved and the production quality is guaranteed, without affecting the output efficiency of the single-wafer process.

[0013] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, the preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0014] Figure 1 This is a schematic structural diagram of a back-washable semiconductor chuck according to an embodiment of the present invention; Figure 2 This is a schematic side view of a back-washable semiconductor chuck according to an embodiment of the present invention; Figure 3 This is a schematic flowchart illustrating a method for cleaning a semiconductor chuck according to an embodiment of the present invention; Figure 4 for Figure 3 A schematic flowchart of step S10; Figure 5 for Figure 3 A schematic flowchart of step S20; In the diagram: 1. Chuck body; 2. Support PIN; 3. Clamping PIN; 4. Backwash assembly; 41. Mounting block; 411. Water outlet; 412. Air outlet; 5. Support base. Detailed Implementation

[0015] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0016] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0017] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances. Furthermore, the technical features involved in the different embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0018] Please see Figure 1 and Figure 2 A preferred embodiment of this application shows a back-washable semiconductor chuck, comprising a chuck body 1, support pins 2, clamping pins 3, and a back-washing assembly 4. The chuck body 1 is used to hold a wafer. A plurality of support pins 2 are spaced apart along the edge of the chuck body 1, and the plurality of support pins 2 cooperate with each other to support the wafer. A plurality of clamping pins 3 are spaced apart along the edge of the chuck body 1, and the plurality of clamping pins 3 cooperate with each other to clamp the wafer. The back-washing assembly 4 is located at the center of the chuck body 1 and is used to perform back-side cleaning and drying of the wafer simultaneously with front-side cleaning and drying.

[0019] According to the embodiment of the present invention, by setting a back-washing component 4 at the center of the chuck body 1, the limitation of the original chuck having only a supporting and fixing function is changed. It realizes that while cleaning and drying the front side of the wafer, the back side of the wafer is cleaned and dried simultaneously using the back-washing component 4. This directly solves the problem of residual liquid after the liquid seeps into the back side from a physical level. By actively flushing the back side with fluid and removing gas, it replaces the inefficient method of passively relying on centrifugal force to remove the liquid, which can thoroughly remove residual liquid on the back side of the wafer and avoid the generation of dirt spots. At the same time, since the back side cleaning and the front side cleaning are carried out simultaneously, the wafer cleanliness is significantly improved and the production quality is guaranteed, without affecting the output efficiency of the single-wafer process.

[0020] The following detailed description uses specific examples: Specifically, please see Figure 1The backwash assembly 4 includes a mounting block 41, which is embedded in the center of the chuck body 1. A water outlet 411 and an air outlet 412 are located at the center of the mounting block 41. The water outlet 411 is connected to the water outlet pipe of the external rinsing robotic arm, and the air outlet 412 is connected to the air outlet pipe of the external rinsing robotic arm. By embedding the mounting block 41 in the center of the chuck body 1 and integrating the water outlet 411 and air outlet 412 at the center of the mounting block 41, pure water and nitrogen provided by the external rinsing robotic arm can be accurately transferred to the central area of ​​the wafer back side. This ensures that the rinsing medium can diffuse evenly from the center to the edge. Combined with the rotation of the chuck body 1, the scouring force of the water flow and the driving force of the airflow achieve comprehensive cleaning of the entire wafer back side, enhancing the practicality and ease of maintenance of the equipment.

[0021] Furthermore, the diameter of the support PIN2 gradually decreases from the end connected to the chuck body 1 to the other end. This design minimizes the physical contact area between the top of the support PIN2 and the back of the wafer. Due to the reduced contact area, the droplet tension formed between the support PIN2 and the wafer decreases, making it more difficult for residual liquid to adhere to and accumulate there. This reduces residual liquid on the back of the wafer, allowing the backwash assembly 4 to rinse away any remaining small amount of liquid, further reducing the likelihood of dirt spots forming on the back.

[0022] Please see Figure 2 The chuck body 1 is equipped with several support seats 5 corresponding to the clamping pins 3, with each clamping pin 3 mounted on its corresponding support seat 5. By mounting the clamping pins 3 on the corresponding support seats 5 on the chuck body 1, a stable mechanical support and positioning reference are provided for the clamping mechanism. The design of the support seats 5 ensures that the clamping pins 3 maintain a high degree of synchronization and structural stability during high-speed rotation, preventing displacement or deformation caused by centrifugal force. This ensures that the wafer remains in a horizontal and centered position throughout the complex wet process, avoiding uneven cleaning caused by wafer misalignment.

[0023] The diameter of the clamping PIN3 is 2mm-3mm. Specifically, in this embodiment, the diameter of the clamping PIN3 is changed from the original 4.5mm to 2.5mm, thereby reducing the contact area with the wafer and further reducing the chemical residue on the back of the wafer in conjunction with the support PIN.

[0024] Please see Figure 3 The present invention also provides a method for cleaning a semiconductor chuck, comprising the following steps: Step S10: After the etching process is completed, the front side of the wafer is cleaned; Step S20: While cleaning the front side of the wafer, the back side of the wafer is simultaneously cleaned by the back cleaning assembly 4.

[0025] Please see Figure 4 Step S10 includes the following steps: Step S101: Rinse the front side of the wafer with pure water; Step S102: After rinsing with pure water, dry the front side of the wafer with nitrogen.

[0026] Please see Figure 5 Step S20 includes the following steps: In step S201: While rinsing the front side of the wafer with pure water, the back side of the wafer is simultaneously rinsed with pure water to remove residual liquid from the back side of the wafer. In step S202, while the front side of the wafer is being dried with nitrogen, the back side of the wafer is also being dried with nitrogen simultaneously.

[0027] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0028] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A washable semiconductor chuck, characterized in that, include: The chuck body, used to hold the wafer; A plurality of support pins are spaced apart along the edge of the chuck body, and the plurality of support pins cooperate with each other to support the wafer; A plurality of clamping pins are spaced apart along the edge of the chuck body, and the plurality of clamping pins cooperate with each other to clamp the wafer; The back-wash assembly is located at the center of the chuck body and is used to perform back-wash and dry operations on the wafer while the front side of the wafer is being cleaned and dried.

2. The washable semiconductor chuck according to claim 1, characterized in that, The backwash assembly includes: An installation block is embedded in the center of the chuck body. A water outlet and an air outlet are provided in the center of the installation block. The water outlet is connected to the water outlet pipe of the external rinsing robotic arm, and the air outlet is connected to the air outlet pipe of the external rinsing robotic arm.

3. The washable semiconductor chuck according to claim 1, characterized in that, The diameter of the support PIN gradually decreases from one end connected to the chuck body to the other.

4. The washable semiconductor chuck according to claim 1, characterized in that, The chuck body is provided with a plurality of support seats corresponding to the clamping PIN, and each clamping PIN is disposed on the corresponding support seat.

5. The washable semiconductor chuck according to claim 4, characterized in that, The diameter of the clamping PIN is 2mm-3mm.

6. A method for cleaning a semiconductor chuck as described in any one of claims 1-5, characterized in that, Includes the following steps: After the etching process is completed, the front side of the wafer is cleaned; While the front side of the wafer is being cleaned, the back side of the wafer is being cleaned simultaneously using the back cleaning assembly.

7. The method for cleaning a semiconductor chuck according to claim 6, characterized in that, The cleaning of the front side of the wafer after the etching process is completed includes the following steps: Rinse the front side of the wafer with pure water; After rinsing with pure water, the front side of the wafer is dried with nitrogen.

8. The method for cleaning a semiconductor chuck according to claim 7, characterized in that, While the front side of the wafer is being cleaned, the back side of the wafer is simultaneously cleaned using the back cleaning assembly, including the following steps: While rinsing the front side of the wafer with pure water, simultaneously rinse the back side of the wafer with pure water to remove residual liquid from the back side of the wafer. While the front side of the wafer is being dried with nitrogen, the back side of the wafer is also being dried with nitrogen simultaneously.

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