Wafer pre-cleaning device

Abstract

The invention discloses a wafer pre-cleaning device, and the device comprises a cleaning part which is hollow; the supporting unit is arranged in the cleaning part and is used for supporting a wafer; the cleaning unit is arranged on the cleaning part and is used for introducing a conducting medium and / or an insulating medium into the cleaning part so as to remove charges on the surface of the wafer; when the wafer is cleaned, the cleaning unit firstly introduces an insulating medium into the cleaning part; and the insulating medium and the conductive medium are introduced into the cleaning part in a mixed manner, so that charges on the surface of the wafer can be taken away in the introduction process of the insulating medium and the conductive medium. According to the invention, the wafer can be pre-cleaned before formal cleaning of the wafer, and charges on the surface of the wafer can be released, so that the surface of the wafer is electrically neutral.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor equipment, and in particular to a wafer pre-cleaning device. Background Art

[0002] Arcing is a common defect in semiconductor manufacturing. It occurs when a localized, transient high-current discharge occurs on the wafer surface, leading to erosion of the underlying material and wafer damage. This defect is particularly common during wet cleaning processes, especially after plasma etching and chemical mechanical polishing.

[0003] In the prior art, residual charge may remain on the wafer surface after processing, which may cause arc discharge during the subsequent wet cleaning process, resulting in wafer damage.

[0004] Therefore, it is necessary to provide a new wafer pre-cleaning device to solve the above problems existing in the prior art. Summary of the Invention

[0005] The object of the present invention is to provide a wafer pre-cleaning device for pre-cleaning wafers before formal cleaning of the wafers, which can release the surface charge of the wafers to make the wafer surface electrically neutral.

[0006] To achieve the above object, the technical solution of the present invention is as follows: A wafer pre-cleaning device, comprising: The cleaning part is hollow; a supporting unit, disposed in the cleaning section and configured to support the wafer; a cleaning unit, provided in the cleaning portion, for introducing a conductive medium and / or an insulating medium into the cleaning portion to remove charges on the surface of the wafer; When cleaning the wafer, the cleaning unit first introduces an insulating medium into the cleaning section; then introduces the insulating medium and the conductive medium into the cleaning section in a mixed manner, so as to remove the charge on the surface of the wafer during the introduction of the insulating medium and the conductive medium.

[0007] By adopting the above technical solution, the wafer is pre-cleaned before the wafer is formally cleaned. During the pre-cleaning process, an insulating medium is first introduced into the cleaning section through the cleaning unit, and then a conductive medium is introduced in proportion. During the introduction process, the content of the conductive medium in the cleaning section gradually increases, so that the conductivity of the liquid in the cleaning section gradually increases slowly, thereby avoiding localized instantaneous high current discharge when the wafer surface contacts a large amount of conductive medium. The surface charge is released in the process of introducing the conductive medium, so that the wafer surface is electrically neutral.

[0008] Optionally, the cleaning unit includes: symmetrically arranged first pipes, respectively provided on opposite side walls of the cleaning portion; The conducting portion is spaced apart from the first pipe and is used to connect the interior of the first pipe with the interior of the cleaning portion, so that the conductive medium and / or the insulating medium flows through the conducting portion into the cleaning portion to clean the wafer along the radial direction of the wafer.

[0009] Optionally, the conducting portion is tilted toward the wafer, and an angle between the conducting portion and a side wall of the cleaning portion is 0-90°, so that the conductive medium flowing through the conducting portion moves toward the wafer in the cleaning portion.

[0010] Optionally, the cleaning unit further includes: a second pipe, communicating with the first pipe symmetrically arranged; a first shunt pipe, one end of which is in communication with the second pipe, and the other end of which is in communication with a first supply device, wherein the first supply device is used to supply an insulating medium into the first shunt pipe; a second shunt pipe, one end of which is in communication with the second pipe, and the other end of which is in communication with a second supply device, the second supply device being used to supply the conductive medium into the first shunt pipe; During the cleaning process, the insulating medium in the first shunt pipe and the conductive medium in the second shunt pipe are proportionally introduced into the second pipe, and enter the cleaning section through the first pipe and the conducting section. When the injected volume of the conductive medium is greater than the volume of the cleaning section, the first shunt pipe is closed and the conductive medium is introduced into the second shunt pipe alone.

[0011] Optionally, also include: a liquid drain portion, disposed around the cleaning portion, and forming a liquid drain cavity with a side wall of the cleaning portion, the liquid drain cavity being used to accommodate liquid overflowing from the cleaning portion; A liquid discharge pipe is provided on a side wall of the liquid discharge portion and is communicated with the liquid discharge cavity so that the liquid in the liquid discharge cavity flows through the liquid discharge pipe and is discharged.

[0012] Optionally, the support unit includes: The spaced-apart clamping parts are all arranged in the cleaning part to support the wafer; the spaced-apart clamping parts are spaced apart in the X-axis direction less than the diameter of the wafer, and in the Z-axis direction less than the radius of the wafer.

[0013] Optionally, the support unit further includes: At least one stabilizing portion is provided in the cleaning portion and distributed between the spaced-apart clamping portions along the X-axis direction. The stabilizing portion is used to contact the wafer to cooperate with the clamping portion to support the wafer.

[0014] Optionally, the center of an inscribed circle formed by the clamping portion and the stabilizing portion is located on the axis of the conducting portion.

[0015] Optionally, a first control valve is provided on the first shunt pipe to adjust the flow of the insulating medium; and a second control valve is provided on the second shunt pipe to adjust the flow of the conductive medium.

[0016] Optionally, a third pipe is connected to the second pipe, and the third pipe is used to connect to a nozzle in the process chamber to spray the wafer before processing the wafer; During spraying, the third pipeline is turned on, the first pipeline is closed, the conductive medium in the second shunt pipeline and the insulating medium in the first shunt pipeline are proportionally introduced into the third pipeline, and the proportion of the conductive medium is gradually increased until the spraying liquid is entirely the conductive medium. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of the main structure of a pre-cleaning device according to an embodiment of the present invention; Figure 2 This is a schematic diagram of a pipe connection method of a cleaning unit according to an embodiment of the present invention; Figure 3 is a schematic diagram of the structure of a support unit according to an embodiment of the present invention; Figure 4 Schematic diagram of another supporting unit structure according to an embodiment of the present invention.

[0018] Reference numerals: 100. Cleaning portion; 110. Support unit; 111. Clamping portion; 112. Stabilizing portion; 121. First pipeline; 122. Conducting portion; 123. Second pipeline; 124. First diversion pipeline; 125. First control valve; 126. Second diversion pipeline; 127. Second control valve; 128. Third pipeline; 200. Draining portion; 210. Drain pipe; 220. Drain cavity. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. Unless otherwise defined, the technical terms or scientific terms used herein should be the common meanings understood by people with ordinary skills in the field to which the invention belongs. The words "including" and similar words used in this article mean that the elements or objects appearing before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects.

[0020] The following is combined with Figure 1-4 , the specific implementation methods of the present invention are further described in detail.

[0021] An embodiment of the present invention provides a wafer pre-cleaning device for pre-cleaning wafers before wafer cleaning. Specifically, when the wafer enters the wet process, there are free charges on its surface. At the moment of contact with the wet liquid, local high-intensity discharge may occur, resulting in arc discharge defects in the wafer. This phenomenon is related to the charge accumulation on the surface of the wafer, which may come from previous process steps, such as plasma etching. In some cases, arc discharge will form burnt or melted areas on the surface of the wafer, affecting the performance and reliability of the device. By pre-cleaning the wafer, the charge on the surface of the wafer is gradually and evenly conducted away, making the surface of the wafer electrically neutral, and then performing normal cleaning steps, this problem can be completely avoided, thereby improving the cleaning quality and increasing the yield rate of the wafer. The wafer pre-cleaning device includes: The cleaning portion 100 is hollow; The support unit 110 is provided in the cleaning unit 100 and is used to support the wafer; A cleaning unit, provided in the cleaning section 100, is used to introduce a conductive medium and / or an insulating medium into the cleaning section 100 to remove charges on the surface of the wafer; When cleaning the wafer, the cleaning unit first introduces an insulating medium into the cleaning section 100; then introduces a mixture of insulating and conductive media into the cleaning section 100 to remove the charge on the wafer surface during the introduction of the insulating and conductive media.

[0022] In some embodiments, reference Figure 1 The cleaning section 100 is hollow, and wafers can be placed in the cleaning section 100 and pre-cleaned therein. Specifically, the cleaning section 100 can be cylindrical or polygonal, without limitation, as long as it can accommodate wafers for pre-cleaning. A quadrilateral barrel-shaped cleaning section 100 is used as an example.

[0023] To facilitate placement of the wafer within the cleaning section 100, a support unit 110 is provided within the cleaning section 100. The support unit 110 is used to support the wafer so that the sidewalls of the wafer do not contact the sidewalls of the cleaning section 100. More specifically, after the wafer is placed on the support unit 110 within the cleaning section 100, the wafer is positioned in the middle of the cleaning section 100, thereby facilitating the cleaning process.

[0024] In some embodiments, reference Figure 1 The sidewall of the cleaning section 100 is provided with a cleaning unit, which can introduce a conductive medium, an insulating medium, or both into the cleaning section 100. When the wafer contacts the insulating medium, no discharge occurs. When the conductive medium contacts the wafer, the charge on the wafer surface can be guided and released through the conductive medium, avoiding charge accumulation. The charge on the wafer surface is carried away by the conductive medium, and at the same time, the ions in the conductive medium can neutralize the charge on the wafer surface, neutralizing the charge on the wafer surface and achieving electrical neutrality.

[0025] In some embodiments, when pre-cleaning the wafer, an insulating medium is first introduced into the cleaning section 100 to completely fill the cleaning section 100 with the insulating medium; then the wafer is placed on the support unit 110 in the cleaning section 100. Alternatively, the wafer may be placed on the support unit 110 of the cleaning section 100 before the insulating medium is introduced into the cleaning section 100. In some embodiments, after the wafer is placed and the insulating medium is filled, a mixed conductive medium and insulating medium are introduced into the cleaning section 100. During the introduction process, the content of the conductive medium in the cleaning section 100 gradually increases, causing the conductivity of the liquid in the cleaning section 100 to gradually and slowly increase. This avoids localized instantaneous high current discharge when the wafer surface contacts a large amount of conductive medium, and releases surface charge during the introduction of the conductive medium, so that the wafer surface is electrically neutral.

[0026] In some embodiments, the insulating medium is deionized water, and the conductive medium is deionized water containing dissolved carbon dioxide.

[0027] In some embodiments, the insulating medium is deionized water and the conductive medium is carbon dioxide gas bubbles. It is worth noting that in this embodiment, the carbon dioxide gas bubbles can be introduced from the bottom of the cleaning section 100 or introduced from the cleaning unit together with the insulating medium. There is no limitation here, and the main purpose is to remove the charge on the wafer surface.

[0028] In some embodiments, the insulating medium may also be a liquid with low electrical conductivity, such as high-purity distilled water or isopropyl alcohol.

[0029] The cleaning unit includes: The symmetrically arranged first pipes 121 are respectively provided on opposite side walls of the cleaning portion 100; The conducting portion 122 is spaced apart from the first pipe 121 and is used to connect the interior of the first pipe 121 with the interior of the cleaning portion 100 so that the conductive medium and / or insulating medium flows through the conducting portion 122 into the cleaning portion 100 to clean the wafer along the radial direction of the wafer.

[0030] In some embodiments, two first pipes 121 are provided, and the two first pipes 121 are respectively provided on opposite side walls of the cleaning section 100 to allow the conductive medium and / or insulating medium to flow into the cleaning section 100 on both sides of the wafer.

[0031] In some embodiments, a plurality of conducting portions 122 are provided, and the plurality of conducting portions 122 are evenly spaced along the axial direction of the first pipe 121 and arranged on the side wall of the first pipe 121, so as to synchronously connect the interior of the first pipe 121 with the interior of the cleaning section 100, so that the conductive medium and / or insulating medium in the first pipe 121 enters the cleaning section 100 through the conducting portions 122. It is worth noting that after the wafer is placed on the support unit 110, the axial direction of the wafer is parallel to the axial direction of the first pipe 121, so that the liquid flowing through the conducting portion 122 can clean the wafer along the radial direction of the wafer. Cleaning the wafer along the radial direction of the wafer can reduce the physical impact on the wafer surface, thereby reducing the impact on the wafer surface, for example, improving the problem that cleaning along the axial direction of the wafer will affect the surface roughness of the wafer.

[0032] In some specific embodiments, the conducting portion 122 is in a hole shape, that is, the conducting portion 122 is opened on the side wall of the first pipe 121 to connect the interior of the first pipe 121 with the interior of the cleaning portion 100 .

[0033] In some specific embodiments, the conducting portion 122 is in the shape of a hollow tube, that is, the conducting portion 122 is fixed to the first pipe 121, one end is connected to the interior of the first pipe 121, and the other end is connected to the interior of the cleaning portion 100, so that the interior of the cleaning portion 100 is connected to the interior of the first pipe 121 through the conducting portion 122.

[0034] The conducting portion 122 is tilted toward the wafer, and the angle between the conducting portion 122 and the sidewall of the cleaning portion 100 is 0-90 degrees, so that the conductive medium flowing through the conducting portion 122 moves toward the wafer in the cleaning portion 100 .

[0035] In some embodiments, the axial direction of the first pipe 121 is defined as the Y-axis direction, the direction perpendicular to the Y-axis in the horizontal direction is defined as the X-axis direction, and the direction perpendicular to the Y-axis in the vertical direction is defined as the Z-axis direction.

[0036] In some embodiments, to facilitate the cleaning process, the conductive portion 122 is configured for cleaning. In some specific embodiments, when the first pipe 121 is provided in the cleaning portion 100 and is positioned at the bottom of the cleaning portion 100, the wafer is positioned above the first pipe 121, and the conductive portion 122 is tilted toward the positive direction of the Z axis, so that the conductive medium flowing through the first pipe 121 and the conductive portion 122 can move toward the wafer, so as to facilitate cleaning the wafer in the radial direction of the wafer. In some specific embodiments, when the first pipe 121 is provided in the cleaning portion 100 and is positioned at the top of the cleaning portion 100, the wafer is positioned below the first pipe 121, and the conductive portion 122 is tilted toward the negative direction of the Z axis, so that the conductive medium flowing through the first pipe 121 and the conductive portion 122 can move toward the wafer, so as to facilitate cleaning the wafer in the radial direction of the wafer.

[0037] In some specific embodiments, the angle between the axis of the conductive portion 122 and the sidewall of the cleaning portion 100 is 0-90°. Specifically, the angle between the axis of the conductive portion 122 and the sidewall of the cleaning portion 100 can be set as needed; for example, when the first pipe 121 is provided in the cleaning portion 100 and is placed at the bottom of the cleaning portion 100, the angle between the conductive portion 122 and the sidewall of the cleaning portion 100 is 30°-60°, so that the conductive medium flowing through the conductive portion 122 can move toward the location of the wafer. More specifically, when the first pipe 121 is provided in the cleaning portion 100 and is placed at the bottom of the cleaning portion 100, the angle between the conductive portion 122 and the sidewall of the cleaning portion 100 is 47°.

[0038] The cleaning unit also includes: The second pipe 123 is connected to the first pipe 121 symmetrically arranged; A first shunt pipe 124, one end of which is in communication with the second pipe 123, and the other end of which is in communication with a first supply device, the first supply device being used to supply an insulating medium into the first shunt pipe 124; A second shunt pipe 126 , one end of which is in communication with the second pipe 123 , and the other end of which is in communication with a second supply device, the second supply device being used to supply the conductive medium into the first shunt pipe 124 ; During the cleaning process, the insulating medium in the first diversion pipe 124 and the conductive medium in the second diversion pipe 126 are proportionally introduced into the second pipe 123, and enter the cleaning section 100 through the first pipe 121 and the conductive portion 122. When the injected volume of the conductive medium is greater than the volume of the cleaning section 100, the first diversion pipe 124 is closed and the second diversion pipe 126 is used to introduce the conductive medium alone.

[0039] In some embodiments, reference Figure 1 and Figure 2To facilitate the flow of a conductive medium or an insulating medium into the first pipe 121, a second pipe 123 is provided, and the second pipe 123 is also connected to the symmetrically arranged first pipe 121. Specifically, one of the first pipes 121 is provided on the side wall of the second pipe 123 and is connected to the interior of the second pipe 123, and the other first pipe 121 is provided at the end of the second pipe 123 and is also connected to the interior of the second pipe 123; or both first pipes 121 are provided on the side wall of the second pipe 123 and are connected to the interior of the second pipe 123, so that the conductive medium and / or insulating medium in the second pipe 123 can enter the first pipe 121.

[0040] In some embodiments, to facilitate the passage of conductive or insulating media, respectively, a first shunt pipe 124 and a second shunt pipe 126 are further provided. Both the first shunt pipe 124 and the second shunt pipe 126 are fixed to the second pipe 123. The fixing method can be adhesive bonding, welding, or integral molding, etc., which are not limited herein. The first shunt pipe 124, the second shunt pipe 126, and the second pipe 123 are primarily fixed and connected. Furthermore, the connection between the first shunt pipe 124 and the second pipe 123 is sealed, and the connection between the second shunt pipe 126 and the second pipe 123 is sealed to reduce the possibility of medium leakage. In some specific embodiments, one end of the first shunt pipe 124 is connected to the second pipe 123, i.e., the fixed and connected manner described above. The other end of the first shunt pipe 124 is used to communicate with a first supply device, which is used to provide an insulating medium. The insulating medium provided by the first supply device enters the second pipe 123 through the first shunt pipe 124, then flows through the first pipe 121 and the conductive portion 122, and then enters the interior of the cleaning unit 100. One end of the second shunt pipe 126 is connected to the second pipe 123, i.e., the fixed and connected manner described above. The other end of the second shunt pipe 126 is used to communicate with a second supply device, which is used to provide a point medium. The conductive medium provided by the second supply device enters the second pipe 123 through the second shunt pipe 126, then flows through the first pipe 121 and the conductive portion 122, and then enters the interior of the cleaning unit 100.

[0041] In some specific embodiments, before wafer pre-cleaning, an insulating medium is first introduced into the second conduit 123 through the first shunt conduit 124. At this time, the second supply device is not activated, i.e., no conductive medium flows through the second shunt conduit 126, until the insulating medium fills the cleaning section 100. During the wafer pre-cleaning process, the first supply device introduces the insulating medium into the second conduit 123 through the first shunt conduit 124, and the second supply device introduces the conductive medium into the second conduit 123 through the second shunt conduit 126, causing the insulating medium and the conductive medium to mix within the second conduit 123. It is noteworthy that the insulating medium and the conductive medium are introduced into the second conduit 123 in proportion and mixed within the second conduit 123, thereby gradually replacing the insulating medium within the cleaning section 100.

[0042] In some specific embodiments, the insulating medium and the conductive medium are injected in a ratio of 1:1.

[0043] In some specific embodiments, the insulating medium and the conductive medium are injected in a ratio of 2:1.

[0044] In some specific embodiments, the insulating medium and the conductive medium are injected in a ratio of 3:2.

[0045] In some more specific embodiments, the amount of conductive medium injected is less than the amount of insulating medium injected, so that a small amount of conductive medium contacts the wafer. The conductive medium content gradually increases, causing the conductivity of the liquid in the cleaning section 100 to gradually and slowly increase, thereby preventing localized instantaneous high-current discharge when the wafer surface contacts a large amount of conductive medium. When the volume of conductive medium injected exceeds the volume of the cleaning section 100, the first diversion conduit 124 is controlled to close or the first supply device stops supplying insulating medium, while the second supply device continues to supply conductive medium, that is, the conductive medium is solely introduced into the second diversion conduit 126 until the conductive medium completely replaces the insulating medium.

[0046] In some more specific embodiments, when the volume of the conductive medium injected reaches 1.2 times the volume of the cleaning section 100, the first diversion conduit 124 is controlled to close or the first supply device stops supplying the insulating medium, while the second supply device continues to supply the conductive medium. Specifically, the conductive medium is introduced solely into the second diversion conduit 126 until the conductive medium completely replaces the insulating medium. When the volume of the conductive medium injected reaches 1.2 times the volume of the cleaning section 100, sufficient contact between the conductive medium and the wafers within the cleaning section 100 is achieved. At this point, the insulating medium needs to be completely removed to allow the conductive medium to contact any residual charge on the wafers. Therefore, the conductive medium is injected solely until the insulating medium is completely replaced.

[0047] The first shunt pipe 124 is provided with a first control valve 125 to adjust the flow of the insulating medium; the second shunt pipe 126 is provided with a second control valve 127 to adjust the flow of the conductive medium.

[0048] In some embodiments, in order to facilitate the control of the ratio of the insulating medium and the conductive medium, a first control valve 125 is set on the first diversion pipe 124, and a second control valve 127 is set on the second diversion pipe 126, wherein the first control valve 125 is used to adjust the flow of the insulating medium in the first diversion pipe 124, and the second control valve 127 is used to adjust the flow of the conductive medium in the second diversion pipe 126.

[0049] In some specific embodiments, the first control valve 125 and the second control valve 127 are both solenoid valves.

[0050] The wafer pre-cleaning device also includes: The drain portion 200 is disposed around the cleaning portion 100 and forms a drain cavity 220 with the sidewall of the cleaning portion 100. The drain cavity 220 is used to accommodate liquid overflowing from the cleaning portion 100. The drain pipe 210 is disposed on a side wall of the drain portion 200 and communicates with the drain cavity 220 , so that the liquid in the drain cavity 220 flows through the drain pipe 210 and is then discharged.

[0051] In some embodiments, reference Figure 1 Since the insulating medium and the conductive medium need to be continuously introduced into the cleaning section 100, it is also necessary to receive excess insulating medium and conductive medium. Specifically, a drainage section 200 is provided on the periphery of the cleaning section 100. The drainage section 200 is disposed around the cleaning section 100, and the bottom of the drainage section 200 is fixed to the bottom or side wall of the cleaning section 100. A drainage cavity 220 is formed between the interior of the drainage section 200 and the inner wall of the cleaning section 100. The drainage cavity 220 is used to accommodate liquid overflowing from the cleaning section 100.

[0052] In some specific embodiments, the top of the cleaning section 100 and the top of the drain section 200 are both opened to facilitate the liquid in the cleaning section 100 to flow into the drain cavity 220. More specifically, the top of the drain section 200 is higher than the top of the cleaning section 100 to reduce the possibility that the insulating medium and the conductive medium in the cleaning section 100 will not overflow into the drain cavity 220.

[0053] In some embodiments, to facilitate the discharge of liquid from the drainage cavity 220, a drainage pipe 210 is fixedly mounted on the sidewall of the drainage portion 200. The fixing method may be bonding, welding, or bolting, etc., which is not limited herein. The main consideration is that the two are fixed and connected to each other, and the fixed portion is sealed to prevent leakage. Specifically, the drainage pipe 210 is connected to the interior of the drainage cavity 220, allowing the liquid in the drainage cavity 220 to be discharged through the drainage pipe 210. More specifically, the drainage pipe 210 is disposed at the bottom of the drainage portion 200 to reduce the possibility that some liquid in the drainage portion 200 will remain and cannot be discharged.

[0054] In order to facilitate placement of the wafer in the cleaning section 100, the support unit 110 includes: The spaced apart clamping parts 111 are all disposed in the cleaning part 100 to support the wafer. The spaced apart clamping parts 111 in the X-axis direction are smaller than the diameter of the wafer, and in the Z-axis direction are smaller than the radius of the wafer.

[0055] In some embodiments, reference Figure 1 , Figure 3 and Figure 4 The support unit 110 includes two clamping portions 111 spaced apart from each other. Specifically, two clamping portions 111 are provided, and the two clamping portions 111 are fixed to the inner wall of the cleaning unit 100. The fixing method can be clamping, welding, or bolting, etc., which is not limited here. The main purpose is that the position of the clamping portion 111 in the cleaning unit 100 does not move. More specifically, the clamping portion 111 is rod-shaped, and the axis of the clamping portion 111 is parallel to the axis of the first pipe 121. The two clamping portions 111 are distributed along the X-axis direction.

[0056] In order to facilitate the support of the wafer, the spacing between the two clamping parts 111 in the X-axis direction is set to be smaller than the diameter of the wafer. When the wafer is placed on the clamping part 111, the two clamping parts 111 are distributed on both sides of the center of the wafer. At the same time, since the distance between the two is smaller than the diameter of the wafer, the wafer will not fall. In order to maintain the stability of the wafer, the spacing between the two clamping parts 111 in the X-axis direction is set to be larger than the radius of the wafer, so as to reduce the possibility of the wafer detaching from the clamping part 111 due to the inability to effectively support the wafer due to the small spacing between the two clamping parts 111. Furthermore, the spacing between the two clamping parts 111 in the Z-axis direction is set to be smaller than the radius of the wafer, so that the distance between the two clamping parts 111 in the Z-axis direction will not be too large, further reducing the possibility of the wafer detaching.

[0057] In some more specific embodiments, there is no gap between the two clamping parts 111 in the Z-axis direction, that is, the axial directions of the two clamping parts 111 are on the same horizontal plane, so as to facilitate the support of the wafer.

[0058] The support unit 110 further includes: At least one stabilizing portion 112 is disposed in the cleaning portion 100 and distributed between the spaced-apart clamping portions 111 along the X-axis direction. The stabilizing portion 112 is configured to contact the wafer to cooperate with the clamping portions 111 to support the wafer.

[0059] In some embodiments, to further enhance wafer stability, a stabilizing portion 112 is provided. The stabilizing portion 112 is fixed to the inner wall of the cleaning section 100. The stabilizing portion 112 may be fixed by clamping, welding, or bolting, without limitation. The stabilizing portion 112 is preferably positioned within the cleaning section 100 to prevent movement. In some embodiments, the stabilizing portion 112 is rod-shaped, and the axial direction of the stabilizing portion 112 is parallel to the axial direction of the first pipe 121.

[0060] In some specific embodiments, there is one stabilizing portion 112 .

[0061] In some specific embodiments, a plurality of stabilizing portions 112 are provided.

[0062] In some more specific embodiments, the stabilizing portion 112 is distributed between the spaced-apart clamping portions 111 along the X-axis direction and is placed at the bottom of at least one clamping portion 111; and after the wafer is placed on the clamping portion 111, it contacts the stabilizing portion 112 so that the stabilizing portion 112 cooperates with the clamping portion 111 to support the wafer.

[0063] In some more specific embodiments, to prevent the wafer from shifting in the Y-axis direction after being placed on the support unit 110, protrusions are provided on the sidewalls of the stabilizing portion 112 and the clamping portion 111. Each stabilizing portion 112 or clamping portion 111 has two protrusions, each spaced apart. When the wafer is placed between the two protrusions, the two protrusions provide support for the wafer, thereby reducing the possibility of the wafer shifting in the Y-axis direction.

[0064] The center of the inscribed circle formed by the clamping portion 111 and the stabilizing portion 112 is located on the axis of the conducting portion 122 .

[0065] In some embodiments, because each stabilizing portion 112 and each clamping portion 111 contacts the sidewall of the wafer, the center of the inscribed circle formed by the stabilizing portion 112 and the clamping portion 111 coincides with the center of the wafer. Simultaneously, the conductive portion 122 is tilted. The center of the inscribed circle formed by the clamping portion 111 and the stabilizing portion 112 is positioned on the axis of the conductive portion 122, allowing the conductive medium flowing through the first conduit 121 and the conductive portion 122 to move toward the center of the wafer, facilitating the wafer pre-cleaning process.

[0066] In some specific embodiments, the conductive portion 122 is in the shape of a hole, and the diameter of the conductive portion 122 is 1 mm to 2 mm. More specifically, the diameter of the conductive portion 122 is 1.7 mm. During the process of introducing the conductive medium, the liquid supply pressure can be adjusted to allow the conductive medium to enter the cleaning section 100 at a slower rate, or the liquid supply pressure can be increased to allow the conductive medium to enter the cleaning section 100 at a faster rate.

[0067] Specifically, the flow state can be determined by the Reynolds number, and the liquid supply pressure can be adjusted according to the Reynolds number to adjust the flow rate of the conductive medium.

[0068] The formula for calculating the Reynolds number is:

[0069] Where ρ is the fluid density (kg / m³); v is the fluid velocity (m / s); d is the characteristic length (such as the pore diameter, in meters); and μ is the dynamic viscosity of the fluid (Pa·s).

[0070] If the Reynolds number is less than 2300, the flow state is laminar, and the fluid flows smoothly without obvious mixing between the layers.

[0071] If the Reynolds number is between 2300 and 4000, the flow is in a transitional state, containing both laminar and possibly turbulent characteristics.

[0072] If the Reynolds number is greater than 4000, the flow is turbulent.

[0073] In this application, the conductive medium is deionized water containing dissolved carbon dioxide. The fluid density ρ, dynamic viscosity μ (at room temperature and pressure, the dynamic viscosity μ changes little after dissolving carbon dioxide, so the dynamic viscosity μ of deionized water containing dissolved carbon dioxide can be considered the same as that of deionized water, i.e., approximately 1.01×10⁻³ Pa·s), and characteristic length d are known. Therefore, the fluid velocity can be calculated and adjusted by adjusting the liquid supply pressure, thereby controlling the flow of the conductive medium in the cleaning section.

[0074] During the cleaning process, the liquid in the cleaning section 100 can be controlled to form turbulence, and when the conductive medium flows along the axis of the conductive section 122 toward the center of the wafer, the turbulence is formed more evenly. The uniformity of the turbulence helps the conductive medium to fully contact the surface of the wafer, thereby more effectively removing the surface charge. This uniform turbulence can ensure that the conductive medium is evenly distributed throughout the cleaning area, avoiding excessively high or low concentrations of the conductive medium in local areas, thereby improving the uniformity of the cleaning effect. In addition, the formation of turbulence can increase the shear force between the liquid and the wafer surface, thereby more effectively removing surface contaminants. And the formation of turbulence helps to disperse the charge in the conductive medium and avoid the formation of high current density in local areas. When the conductive medium flows along the axis of the conductive section 122 toward the center of the wafer, the dispersing effect of the turbulence can effectively reduce the risk of local high current discharge, thereby protecting the wafer surface from arc damage.

[0075] More specifically, the inclined arrangement of the conducting portion 122 can increase the shear force of the fluid between the conducting portion 122 and the wafer surface. This shear force will break the laminar state of the fluid, promote the mixing and disturbance of the fluid, and thus more easily form turbulence. At the same time, the relatively arranged conducting portions 122 enable the conductive cutoffs in the two first pipes 121 to impact the wafer when the conductive medium enters the cleaning portion 100. This impact will increase the degree of mixing of the fluid and further enhance the formation of turbulence. More specifically, since an insulating medium is already present inside the cleaning portion 100 when the conductive medium is introduced, when the conductive medium ejected from the relatively arranged first pipes 121 moves to the position of the wafer, its impact force has been weakened by the insulating medium. Therefore, while facilitating the formation of turbulence, it will not cause a strong impact on the wafer surface.

[0076] A third pipe 128 is connected to the second pipe 123 and is used to connect to a nozzle in the process chamber to spray the wafer before wafer processing. During spraying, the third pipe 128 is turned on, the first pipe 121 is closed, and the conductive medium of the second diversion pipe 126 and the insulating medium of the first diversion pipe 124 are proportionally introduced into the third pipe 128, and the proportion of the conductive medium is gradually increased until the spraying liquid is all conductive medium.

[0077] In some embodiments, reference Figure 1 and Figure 2A third pipe 128 is fixedly mounted on the second pipe 123. A solenoid valve is provided on the third pipe 128 to control the flow of the third pipe 128. Additionally, a solenoid valve is also provided on the second pipe 123 to control the flow of the second pipe 123. It is worth noting that the third pipe 128 and the second pipe 123 are generally not opened at the same time. The solenoid valve on the second pipe 123 is positioned so as to prevent further flow of medium into the first pipe 121 when the solenoid valve is closed.

[0078] In some specific embodiments, the third pipe 128 is used to connect to the nozzle in the process chamber to spray the wafer before wafer processing; during spraying, the third pipe 128 is turned on and the first pipe 121 is closed. At this time, the conductive medium in the second diverter pipe 126 and the insulating medium in the first diverter pipe 124 will enter the third pipe 128 through the second pipe 123. Specifically, after the wafer is fixed in the chamber of the cleaning machine, the second diverter pipe 126 is controlled to be closed, and the insulating medium is first sprayed onto the wafer through the first diverter pipe 124. Then, the second diverter pipe 126 is opened. The first diverter pipe 124 cooperates with the second diverter pipe 126 to proportionally introduce the insulating medium and the conductive medium. Then, the ratio of the conductive medium to the insulating medium in the liquid is gradually increased, so that the resistivity of the sprayed liquid gradually and slowly decreases until all the liquid sprayed from the nozzle is the conductive medium. This step ensures that the resistivity of the spray liquid changes gradually and slowly during wafer cleaning, thereby avoiding localized instantaneous high current discharge when the wafer surface is in direct contact with the conductive medium, and releasing surface charge during the entire cleaning process.

[0079] The implementation principle of a wafer pre-cleaning device in an embodiment of the present application is to pre-clean the wafer before the wafer is formally cleaned. During the pre-cleaning process, the wafer is first immersed in an insulating medium, and then a conductive medium is introduced in proportion. During the introduction process, the content of the conductive medium in the cleaning part 100 gradually increases, so that the conductivity of the liquid in the cleaning part 100 gradually increases slowly, thereby avoiding local instantaneous high current discharge when the wafer surface contacts a large amount of conductive medium. The surface charge is released in the process of introducing the conductive medium to make the wafer surface electrically neutral.

[0080] While the embodiments of the present invention have been described in detail above, it will be apparent to those skilled in the art that various modifications and variations of these embodiments are possible. However, it should be understood that such modifications and variations are within the scope and spirit of the present invention as set forth in the claims. Furthermore, the invention described herein is susceptible to other embodiments and may be practiced or implemented in a variety of ways.

Claims

1. A wafer pre-cleaning device, characterized in that: include: The cleaning portion (100) is hollow; A supporting unit (110), disposed in the cleaning portion (100), and configured to support the wafer; a cleaning unit, provided in the cleaning portion (100), for introducing a conductive medium and / or an insulating medium into the cleaning portion (100) to remove charges on the surface of the wafer; When cleaning the wafer, the cleaning unit first introduces an insulating medium into the cleaning portion (100); and then introduces the insulating medium and the conductive medium into the cleaning portion (100) in a mixed manner, so as to remove the charge on the surface of the wafer during the process of introducing the insulating medium and the conductive medium.

2. The wafer pre-cleaning device according to claim 1, characterized in that: The cleaning unit comprises: symmetrically arranged first pipes (121), respectively provided on opposite side walls of the cleaning portion (100); The conducting portion (122) is spaced apart from the first pipe (121) and is used to connect the interior of the first pipe (121) with the interior of the cleaning portion (100), so that the conductive medium and / or the insulating medium flows through the conducting portion (122) into the cleaning portion (100), and the wafer is cleaned along the radial direction of the wafer.

3. The wafer pre-cleaning device according to claim 2, characterized in that: The conducting portion (122) is tilted toward the wafer, and the angle between the conducting portion (122) and the side wall of the cleaning portion (100) is 0-90 degrees, so that the conductive medium flowing through the conducting portion (122) moves toward the wafer in the cleaning portion (100).

4. The wafer pre-cleaning device according to claim 2, characterized in that: The cleaning unit also includes: a second pipe (123) communicating with the first pipe (121) symmetrically arranged; a first shunt pipe (124), one end of which is in communication with the second pipe (123), and the other end of which is in communication with a first supply device, wherein the first supply device is used to supply an insulating medium into the first shunt pipe (124); a second shunt pipe (126), one end of which is in communication with the second pipe (123), and the other end of which is in communication with a second supply device, the second supply device being used to supply a conductive medium into the first shunt pipe (124); During the cleaning process, the insulating medium in the first shunt pipe (124) and the conductive medium in the second shunt pipe (126) are introduced into the second pipe (123) in proportion, and enter the cleaning section (100) via the first pipe (121) and the conducting section (122). When the injected volume of the conductive medium is greater than the volume of the cleaning section (100), the first shunt pipe (124) is closed, and the second shunt pipe (126) is allowed to introduce the conductive medium alone.

5. The wafer pre-cleaning device according to claim 1, characterized in that: Also includes: a liquid drain portion (200) disposed around the cleaning portion (100) and forming a liquid drain cavity (220) with a side wall of the cleaning portion (100), wherein the liquid drain cavity (220) is used to accommodate liquid overflowing from the cleaning portion (100); A liquid discharge pipe (210) is provided on a side wall of the liquid discharge portion (200) and is in communication with the liquid discharge cavity (220), so that the liquid in the liquid discharge cavity (220) flows through the liquid discharge pipe (210) and is discharged.

6. The wafer pre-cleaning device according to claim 2, characterized in that: The support unit (110) comprises: The spaced-apart clamping parts (111) are all arranged in the cleaning part (100) to support the wafer; the spaced-apart clamping parts (111) are spaced apart in the X-axis direction less than the diameter of the wafer, and are spaced apart in the Z-axis direction less than the radius of the wafer.

7. The wafer pre-cleaning device according to claim 6, characterized in that: The support unit (110) further includes: At least one stabilizing portion (112) is provided in the cleaning portion (100) and is distributed between the spaced-apart clamping portions (111) along the X-axis direction. The stabilizing portion (112) is used to contact the wafer to cooperate with the clamping portion (111) to support the wafer.

8. The wafer pre-cleaning device according to claim 7, characterized in that: The center of the inscribed circle formed by the clamping portion (111) and the stabilizing portion (112) is located on the axis of the conducting portion (122).

9. The wafer pre-cleaning device according to claim 4, characterized in that: The first shunt pipe (124) is provided with a first control valve (125) for adjusting the flow of the insulating medium; the second shunt pipe (126) is provided with a second control valve (127) for adjusting the flow of the conductive medium.

10. The wafer pre-cleaning device according to claim 4, characterized in that: The second pipe (123) is connected to a third pipe (128), and the third pipe (128) is used to connect to a nozzle in a process chamber to spray the wafer before the wafer is processed; During spraying, the third pipe (128) is turned on, the first pipe (121) is closed, the conductive medium in the second shunt pipe (126) and the insulating medium in the first shunt pipe (124) are proportionally introduced into the third pipe (128), and the proportion of the conductive medium is gradually increased until the spraying liquid is entirely the conductive medium.

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