Wafer cleaning apparatus and wafer post processing equipment

Abstract

The application discloses a wafer cleaning device and wafer post-processing equipment, the wafer cleaning device comprises a box body, a supporting part is arranged in the box body to vertically support a wafer to be cleaned, a vibrating plate is arranged in the box body to provide high-frequency vibration from the side, and a liquid spraying part sprays fluid towards an inner groove formed by the vibrating plate to overflow and discharge the contaminants stripped by the high-frequency vibration from the top of the inner groove.

Description

Technical Field

[0001] This invention belongs to the field of wafer post-processing technology, and more specifically, relates to a wafer cleaning apparatus and wafer post-processing equipment. Background Technology

[0002] The integrated circuit industry is the core of the information technology industry, playing a crucial role in promoting the digital and intelligent transformation and upgrading of the manufacturing industry. Chips are the carriers of integrated circuits, and chip manufacturing involves processes such as integrated circuit design, wafer fabrication, wafer processing, electrical measurement, dicing, packaging, and testing. Among these, chemical mechanical polishing (CMP) is one of the five core processes in wafer fabrication.

[0003] Chemical mechanical polishing (CMP) is an ultra-precision surface finishing technique that achieves global planarization. In CMP, the wafer is typically held in place by the bottom surface of a support head, with the side of the wafer containing the deposited layer resting against the upper surface of a polishing pad. The support head rotates in the same direction as the polishing pad under the actuation of a drive assembly, applying a downward load to the wafer. Polishing fluid is supplied to the upper surface of the polishing pad and distributed between the wafer and the pad, allowing the wafer to undergo chemical and mechanical polishing through a combination of chemical and mechanical processes.

[0004] After chemical mechanical polishing (CMP), wafers require post-processing such as cleaning and drying to prevent contamination of semiconductor devices by trace ions and metal particles, thus ensuring the performance and yield of the semiconductor devices. Wafer cleaning methods include roller brush cleaning and megasonic cleaning, with megasonic cleaning being one of the most commonly used methods.

[0005] Figure 1 This is a schematic diagram of a mega-sound cleaning device in the prior art. The mega-sound cleaning device includes a cleaning tank 10', a mega-sound vibrating plate 20' at the bottom of the cleaning tank 10', and a wafer W to be cleaned positioned directly above the mega-sound vibrating plate 20'. The mega-sound vibrating plate 20' emits high-frequency sound waves to remove contaminants such as tiny particles from the surface of the wafer W. Simultaneously, a nozzle 30' is configured at the bottom of the cleaning tank 10', and the nozzle 30' has multiple nozzles that spray cleaning fluid obliquely upwards and overflow from the top of the cleaning tank 10' to discharge the stripped contaminants to the outside of the cleaning tank 10'.

[0006] In the prior art, the megaacoustic transducer 20' is placed at the bottom of the cleaning tank 10', which is far from the wafer to be cleaned. The high-frequency sound waves emitted by the megaacoustic transducer 20' attenuate in the fluid. When the high-frequency sound waves act on the bottom of the wafer, their intensity is attenuated to a certain extent. Figure 1 In the middle, the area corresponding to the vertical distance H between the mega-acoustic resonator 20' and the bottom of the wafer W is the region of ineffective acoustic attenuation; Figure 1The graph uses dashed lines to represent the attenuation of sound waves. The horizontal axis represents the sound wave intensity, and the vertical axis represents the radial position of the sound wave reaching the wafer. When high-frequency sound waves reach the top of the wafer, their intensity may not be able to effectively remove contaminants, which will result in a poor cleaning effect on the top of the wafer and fail to meet the process requirements.

[0007] Existing cleaning tanks 10' are typically rectangular tanks, where the sprayed cleaning fluid experiences significant backflow and turbulence, such as Figure 2 As shown, this can lead to secondary contamination as contaminants detached from the wafer surface cannot be removed in a timely manner. Furthermore, the large volume of the rectangular tank consumes a significant amount of cleaning solution, increasing the cost of wafer cleaning. Summary of the Invention

[0008] This invention provides a wafer cleaning apparatus and wafer post-processing equipment, aiming to solve at least one of the technical problems existing in the prior art.

[0009] A first aspect of the present invention provides a wafer cleaning apparatus, comprising:

[0010] Box;

[0011] A support section, which is located in the housing, vertically supports the wafer to be cleaned;

[0012] The vibrating plate is inclinedly arranged in the box to provide high-frequency vibration from the side;

[0013] The spray section sprays fluid toward the inner tank formed by the vibrating plate to overflow and discharge contaminants stripped off by high-frequency vibration from the top of the inner tank.

[0014] In some embodiments, the inner groove is vertically disposed in the box, and the vibrating plate is disposed to the side of the vertical center line of the inner groove.

[0015] In some embodiments, the inner tank includes a base section, a rectifier section, and a contraction section. The base section is located at the bottom of the inner tank, the rectifier section is disposed at the upper end of the base section, the vibrating plate extends outward at an angle along the upper end of the rectifier section, and the contraction section extends inward at an angle along the upper end of the vibrating plate.

[0016] In some embodiments, the horizontal distance between the rectifying section and the vertical centerline of the inner tank is less than the horizontal distance between the contraction section and the vertical centerline of the inner tank.

[0017] In some embodiments, the spray section is disposed below the vibrating plate.

[0018] In some embodiments, the support portion is located in the base section of the inner tank, and the spray portion is located below the support portion.

[0019] In some embodiments, the spray section is disposed on the base section, and the spray section is disposed at an angle downward to spray fluid toward the bottom of the base section.

[0020] In some embodiments, the angle between the vibrating plate and the horizontal plane is 2-30°.

[0021] In some embodiments, at least a portion of the vibrating plate is located below the central axis of the wafer to be cleaned.

[0022] In some embodiments, the width of the vibrating plate is 10-50 mm.

[0023] In some embodiments, the number of the vibrating plates is a pair, which are symmetrically arranged on both sides of the inner groove.

[0024] A second aspect of the present invention provides a wafer post-processing apparatus, which includes the wafer cleaning apparatus described above.

[0025] The beneficial effects of this invention include:

[0026] a. Place the vibrating plate to the side of the wafer to be cleaned to reduce the distance between the vibrating plate and the wafer, reduce the attenuation of high-frequency sound waves, and ensure the effect of mega-acoustic cleaning;

[0027] b. The vibrating plate is placed below the central axis of the wafer so that the high-frequency sound waves emitted by the vibrating plate can cover the upper half of the wafer; the support can drive the wafer to rotate around the central axis to cover all areas of the wafer, thereby achieving mega-sound cleaning of the wafer.

[0028] c. The spray section for overflow discharge is located at the bottom of the inner tank, away from the vibrating plate, in order to reduce or avoid interference of the sprayed cleaning fluid with the high-frequency sound waves.

[0029] d. The spray nozzle is tilted downwards and sprays cleaning fluid in an alternating pattern to control the degree of turbulence of the cleaning fluid in the inner tank and ensure that the rectified fluid direction is vertical;

[0030] e. The inner tank of the wafer cleaning device is equipped with a rectifier section to rectify the fluid sprayed by the spray section, reduce or avoid backflow or turbulence of the fluid in the inner tank, and prevent the particles stripped by mega-acoustic stripping from re-adhering to the wafer surface.

[0031] f. The inner tank of the wafer cleaning apparatus is provided with a shrinking section to control the space between the shrinking section and the wafer. Sound waves can be reflected in the space to maintain the sound pressure intensity of the inner tank. At the same time, the shrinking section of the inner tank can reduce the size of the inner tank chamber and reduce the amount of cleaning fluid used by the spraying section, which helps to control the cost of wafer cleaning. Attached Figure Description

[0032] The advantages of the present invention will become clearer and easier to understand through the following detailed description in conjunction with the accompanying drawings, which are merely illustrative and do not limit the scope of protection of the present invention, wherein:

[0033] Figure 1 This is a schematic diagram of a mega-sound cleaning device in the prior art;

[0034] Figure 2 yes Figure 1 The corresponding flow field diagram inside the mega-sound cleaning device;

[0035] Figure 3 This is a schematic diagram of a circular cleaning device provided in an embodiment of the present invention;

[0036] Figure 4 yes Figure 3 A schematic diagram of the corresponding inner groove;

[0037] Figure 5 This is a sound pressure intensity curve in the inner groove provided in an embodiment of the present invention;

[0038] Figure 6 This is a schematic diagram of a spray section provided in an embodiment of the present invention;

[0039] Figure 7 This is a flow field diagram inside a circular cleaning device provided in an embodiment of the present invention;

[0040] Figure 8 This is a schematic diagram of a circular cleaning device provided in another embodiment of the present invention;

[0041] Figure 9 yes Figure 8 A schematic diagram of the corresponding inner groove;

[0042] Figure 10 yes Figure 8 The diagram shows the sound pressure intensity curve of the inner tank of the wafer cleaning device;

[0043] Figure 11 This is a sound pressure intensity curve corresponding to a mega-sound cleaning device in the existing technology;

[0044] Figure 12 This is a schematic diagram of a chemical mechanical polishing system provided in an embodiment of the present invention. Detailed Implementation

[0045] The technical solutions of the present invention will be described in detail below with reference to specific embodiments and accompanying drawings. The embodiments described herein are specific implementations of the present invention, used to illustrate the concept of the present invention; these descriptions are explanatory and exemplary, and should not be construed as limiting the implementation methods or the scope of protection of the present invention. In addition to the embodiments described herein, those skilled in the art can employ other obvious technical solutions based on the content disclosed in the claims and specification of this application. These technical solutions include those that make any obvious substitutions and modifications to the embodiments described herein.

[0046] The accompanying drawings in this specification are schematic diagrams used to illustrate the concept of the invention and to schematically show the shapes of the various parts and their interrelationships. It should be understood that, in order to clearly show the structure of the various components of the embodiments of the invention, the drawings are not drawn to the same scale, and the same reference numerals are used to indicate the same parts in the drawings.

[0047] In this invention, a wafer (W) is also called a substrate, which has the same meaning and practical function.

[0048] Figure 3 This is a schematic diagram of a wafer cleaning apparatus 100 provided in an embodiment of the present invention, which includes:

[0049] The housing 10 has a rectangular groove structure, and the interior of the housing 10 is equipped with components for cleaning wafers; the top of the housing 10 is equipped with a switch door (not shown), through which an external robotic arm can place wafers into the housing 10; or, the external robotic arm can remove the cleaned wafers from the housing 10 through the switch door.

[0050] A support portion 20, disposed within the housing 10, vertically supports the wafer W to be cleaned; specifically, the support portion 20 includes at least a pair of rollers. Figure 2 As shown in the diagram, the rollers are located at the lower part of the housing 10, so that the grooves of the rollers can engage with the edge of the wafer to be cleaned, so that the wafer W is in a vertical state; at the same time, the end of the rollers is also equipped with a drive motor (not shown), which can drive the rollers to rotate around the axis, so as to drive the wafer to rotate under the action of friction between the roller grooves and the wafer; in some embodiments, the support 20 includes a pair of rollers and a speed measuring wheel, all three of which are engaged with the outer edge of the wafer to be cleaned, and the speed measuring wheel is located in the middle of the pair of rollers to monitor the operating status of the wafer;

[0051] The vibrating plate 30, also known as a transducer, is inclinedly disposed within the housing 10 to provide high-frequency vibration from the side. The high-frequency sound waves emitted by the vibrating plate 30 act on the surface of the wafer to be cleaned, thereby stripping away contaminants adhering to the wafer surface. The transducer converts the electrical output of the power supply into a vibration output, and the generated sound waves are transmitted in the fluid. Under the action of cavitation and acoustic wave flow, particulate matter adhering to the wafer surface is stripped away.

[0052] In this invention, the vibrating plate 30 is disposed on the side of the wafer to be cleaned, and its distance from the wafer W is relatively close to reduce the attenuation of the high-frequency sound waves emitted by the vibrating plate 30, ensuring the effects of cavitation and sound wave flow, and fully peeling the particulate matter from the surface of the wafer to achieve a good mega-sound cleaning effect.

[0053] Furthermore, the housing 10 is also equipped with an inner groove 40, which is located inside the housing 10, such as... Figure 3 As shown. The aforementioned vibrating plate 30, together with other plates, forms an inner groove 40, with the support part 20 disposed at the bottom of the inner groove 40. That is, the wafer W to be cleaned is vertically disposed in the inner groove 40. This arrangement helps to reduce the space required for the megaacoustic cleaning of the wafer W, allowing high-frequency sound waves to effectively act on the wafer surface.

[0054] Figure 3 In the illustrated embodiment, the wafer cleaning apparatus 100 further includes a spray section 50, which sprays fluid toward the inner tank 40 to overflow and discharge contaminants such as particulate matter stripped by high-frequency acoustic waves from the top of the inner tank 40. Specifically, the inner tank 40 has an opening at the top, and the fluid sprayed by the spray section 50 can fill the inner tank 40 and overflow from the top opening of the inner tank 40 to discharge the stripped contaminants between the housing 10 and the inner tank 40.

[0055] In one embodiment of the present invention, an inner tank 40 is vertically disposed within a housing 10, and a wafer W to be cleaned is disposed along the vertical centerline of the inner tank 40. A vibrating plate 30, which provides high-frequency acoustic waves for wafer cleaning, is disposed to the side of the vertical centerline of the inner tank 40. That is, the vibrating plate 30 is disposed to the side of the wafer W to provide high-frequency acoustic waves from the side of the wafer, generating cavitation and acoustic wave flow effects inside the inner tank 40, stripping away particles adhering to the wafer surface to thoroughly clean the wafer surface.

[0056] Figure 4 This is a schematic diagram of an inner tank 40 provided in an embodiment of the present invention. The inner tank 40 also includes a base section 41, a rectifier section 42 and a contraction section 43. The base section 41, the rectifier section 42 and the contraction section 43 are arranged vertically from bottom to top to form a tank structure with an open top.

[0057] Furthermore, the base segment 41 is located at the bottom of the inner tank 40, and its longitudinal cross-section is a rectangular structure. The support portion 20 is disposed inside the base segment 41 to vertically support the wafer to be cleaned. Furthermore, compared to other parts of the inner tank 40, the base segment 41 has a larger lateral clearance to provide sufficient space for the placement of the support portion 20. In this invention, the lateral clearance of the base segment 41 refers to the clearance between the corresponding inner sidewalls of the base segment 41.

[0058] The rectifier section 42 is located at the upper end of the base section 41. Specifically, the rectifier section 42 is a tank structure enclosed by a plate-like structure, which is vertically positioned above the base section 41.

[0059] Furthermore, the lateral gap of the rectifier section 42 is abruptly reduced. This design can regulate the flow of fluid, avoid disturbance of the fluid in the corresponding chamber of the base section 41, prevent particles stripped from the wafer from re-attaching to the wafer surface, and ensure the cleaning effect of the wafer.

[0060] In some embodiments, the width corresponding to the lateral gap of the rectifying section 42 is 1 / 3 to 2 / 3 of the width corresponding to the lateral gap of the base section 41 to achieve a good rectification effect. Specifically, the spray section 50 sprays fluid toward the bottom surface of the base section 41, and the fluid is repeatedly splashed in the base section 41 to form turbulence. These turbulent fluids become smooth after being rectified by the rectifying section 42 with a small lateral gap; the smooth fluid is then transported upward through the rectifying section 42 to wash away particles on the wafer surface and overflow from the top opening of the inner tank 40.

[0061] Preferably, the width of the transverse gap of the rectifying section 42 is 1 / 3 to 1 / 2 of the width of the transverse gap of the base section 41, so that the fluid sprayed by the spraying section 50 becomes smooth after being rectified by the rectifying section 42. The rectified fluid can be transported upward in a roughly vertical direction to reduce backflow and turbulence, avoid the stripped particles from re-adhering to the wafer surface and causing secondary contamination, and achieve a good cleaning effect.

[0062] Furthermore, the vibrating plate 30 is arranged to extend outward at an angle along the upper end of the rectifier section 42, such as... Figure 4 As shown. Specifically, the vibrating plate 30 extends upward and outward from the end of the rectifier section 42, so that the high-frequency sound waves generated by the vibrating plate 30 can be transmitted obliquely to the wafer surface, so as to remove particulate matter from the wafer surface by utilizing cavitation and acoustic wave flow effects. In this invention, the outward tilt of the components of the inner groove 40 refers to tilting towards the outside of the inner groove 40, and the inward tilt of the components of the inner groove 40 refers to tilting towards the vertical centerline of the inner groove 40.

[0063] Furthermore, the contraction section 43 of the inner tank 40 extends inwardly at the upper end of the vibrating plate 30, that is, the contraction section 43 extends upward and inward. The width of the transverse gap corresponding to the contraction section 43 gradually decreases from bottom to top, forming a contraction space. The high-frequency sound waves generated by the vibrating plate 30 are transmitted in the contraction space between the contraction section 43 and the wafer W, so as to concentrate the transmission towards the upper part of the wafer W; at the same time, the high-frequency sound waves generated by the vibrating plate 30 can be reflected to the wafer surface in the contraction space to enhance the sound pressure intensity of the inner tank 40 and improve the cleaning effect of the wafer.

[0064] Figure 4 In the diagram, dashed lines represent the transmission path of the high-frequency sound waves emitted by the vibrating plate 30 between the inner wall of the contraction section 43 and the wafer W. It can be seen that the reflection of high-frequency sound waves can enhance the efficiency of mega-acoustic cleaning and improve the effect of wafer cleaning.

[0065] In some embodiments, the angle between the shrinkage section 43 and the vertical center line of the inner groove 40 is 2-20°; preferably, the angle between the shrinkage section 43 and the vertical center line of the inner groove 40 is 5-15°, so as to reasonably control the space between the inner sidewall of the shrinkage section 43 and the wafer W, and ensure the transmission and reflection effect of high-frequency sound waves.

[0066] To ensure efficient sound wave reflection from the inner wall of the contraction section 43, its roughness should be controlled within Ra0.1. Simultaneously, the contraction section 43 should be made of a hydrophobic material to prevent particulate matter from adhering to its inner wall. If a large amount of particulate matter adheres to the inner wall of the contraction section 43, diffuse reflection of sound waves will occur, which is detrimental to maintaining the sound pressure level of the inner tank 40 and hinders the achievement of good megaacoustic cleaning results.

[0067] In some embodiments, the base section 41, the rectifying section 42, and the contraction section 43 of the inner tank 40 are made of polytetrafluoroethylene (PTFE). PTFE has high lubricity and non-adhesion properties to prevent particles stripped by megaphonic cleaning from adhering to the inner wall of the inner tank 40 and affecting the reflection of sound waves, thereby controlling the sound pressure intensity of the inner tank 40 and ensuring good cleaning results.

[0068] It is understood that the inner groove 40 may also adopt other structural forms, as long as it is equipped with a scheme to enhance sound wave reflection or a similar scheme, it will fall within the protection scope and disclosure scope of this embodiment.

[0069] Figure 5 The diagram shows the sound pressure intensity curve in the inner groove 40. Because the contraction section 43 of the inner groove 40 has a sound wave reflection effect, the sound pressure intensity increases in this section. This is beneficial for enhancing the cavitation and acoustic flow effects of high-frequency sound waves, thereby effectively stripping particles from the wafer surface and achieving particle cleaning.

[0070] During mega-acoustic cleaning of the wafer, the wafer W rotates around its central axis, allowing the high-frequency sound waves emitted by the vibrating plate 30 to fully cover the wafer surface, thus cleaning every area of ​​the wafer and avoiding mega-acoustic cleaning blind spots that would affect the wafer cleaning effect.

[0071] In this invention, the vibrating plate 30 is positioned facing the surface of the wafer W to be cleaned, so as to emit high-frequency sound waves toward the surface to be cleaned. Figure 4 In this process, the vibrating plate 30 is disposed on one side of the wafer W to be cleaned, that is, the vibrating plate 30 is disposed facing the front side of the wafer, so as to clean the wafer surface by mega-sound cleaning. In this invention, the so-called front side of the wafer refers to the side on which the electronic devices are arranged; the so-called back side of the wafer refers to the non-arranged side of the electronic devices, that is, the opposite side of the front side of the wafer.

[0072] As one aspect of this embodiment, the angle between the vibrating plate 30 and the horizontal plane is 2-30°; preferably, the angle between the vibrating plate 30 and the horizontal plane is 5-15°, so that the high-frequency sound waves emitted by the vibrating plate 30 are transmitted obliquely upward to fully remove particles from the wafer surface. During mega-acoustic cleaning, the wafer rotates around the central axis under the drive of the support 20, so that the high-frequency sound waves emitted by the vibrating plate 30 can act on the side surface of the wafer.

[0073] In this invention, the vibrating plate 30 is inclined, and the component of the sound wave emitted by it is perpendicular to the wafer surface. This is beneficial to improve the removal rate and ensure the cleaning effect of the wafer. At the same time, the inclined setting of the vibrating plate 30 is beneficial to reduce the interference of air bubbles during the cleaning process and enhance the vibration effect on particles.

[0074] In one embodiment of the present invention, the width of the vibrating plate 30 is 10-50 mm. Here, the width of the vibrating plate 30 refers to the dimension corresponding to the longitudinal section of the vibrating plate 30, i.e. Figure 4 In the middle, the distance between the upper end of the rectifier section 42 and the lower end of the contraction section 43. The width of the vibrating plate 30 is set within a certain range to ensure that the high-frequency sound waves emitted by the vibrating plate 30 cover the wafer radius as much as possible, thus ensuring the wafer cleaning effect.

[0075] Understandably, the width of the vibrating plate 30 should not be too large in order to control the size of the inner tank 40, reduce the amount of cleaning fluid used, and control the cost of wafer cleaning. Preferably, the width of the vibrating plate 30 is 15-30 mm.

[0076] In this invention, the vibrating plate 30 extends horizontally. Figure 7 (As shown), its lateral length should be greater than the diameter of the wafer, or the lateral length of the vibrating plate 30 should be greater than the chord length of the wafer (i.e., the length corresponding to the horizontal projection of the vibrating plate 30 on the wafer), so that the ultrasonic waves generated by the vibrating plate 30 can cover the surface of the wafer.

[0077] As an embodiment of the present invention, the vibrating plate 30 is made of an electroacoustic material; specifically, the vibrating plate 30 is made of a piezoelectric material so as to convert electrical energy into vibration and form high-frequency sound waves. Preferably, the vibrating plate 30 is made of lead zirconate titanate (PZT) piezoelectric ceramic, barium titanate (BaTiO3) piezoelectric ceramic, etc.

[0078] In one embodiment of the present invention, at least a portion of the vibrating plate 30 is located below the central axis of the wafer to be cleaned, so as to ensure that the high-frequency sound waves emitted by the vibrating plate 30 can be transmitted in the radial direction. The wafer rotates around the central axis during mega-acoustic cleaning, so that the high-frequency sound waves can fully cover all areas of the wafer.

[0079] Figure 4 In the illustrated embodiment, the horizontal distance between the rectifier section 42 and the vertical centerline of the inner tank 40 is less than the horizontal distance between the contraction section 43 and the vertical centerline of the inner tank 40. Because the upper end of the self-vibrating plate 30 of the contraction section 43 is inclined upwards and inwards, the horizontal distance between the upper end of the contraction section 43 and the vertical centerline of the inner tank 40 is minimized. In this embodiment, the horizontal distance between the rectifier section 42 and the vertical centerline of the inner tank 40 is less than the minimum horizontal distance between the contraction section 43 and the vertical centerline of the inner tank 40.

[0080] As one aspect of this embodiment, the horizontal distance between the rectifier section 42 and the vertical center line of the inner tank 40 is 2-15mm, and the horizontal distance between the contraction section 43 and the vertical center line of the inner tank 40 is 5-25mm. This arrangement helps to control the internal space of the inner tank 40, increase the sound pressure intensity inside the inner tank 40, meet the requirements of wafer mega-acoustic cleaning, and obtain a good cleaning effect.

[0081] Figure 4 In the inner tank 40, the constriction section 43 opposite the wafer cleaning surface is inclined, while the constriction section 43 opposite the wafer cleaning surface is vertically arranged to reduce the internal space of the inner tank 40 and control the sound pressure intensity of the inner tank 40. Furthermore, this arrangement also helps to reduce the amount of cleaning fluid used, controlling the cost of wafer cleaning. That is, the spray section 50 located at the bottom of the inner tank 40 can fill the inner tank 40 with a small amount of cleaning fluid, cleaning particles in the inner tank 40 through overflow.

[0082] To ensure good overflow effect and timely clean up particulate matter in the inner tank 40, the spray section 50 is positioned below the vibrating plate 30, so that the fluid sprayed by the spray section 50 is far away from the vibrating plate 30, avoiding the influence of turbulent fluid on the high-frequency sound waves emitted by the vibrating plate 30, and avoiding the mutual interference between mega-sound cleaning and overflow discharge.

[0083] Furthermore, the support part 20 is located in the base section 41 of the inner tank 40, and the spray part 50 is located below the support part 20. The cleaning liquid sprayed by the spray part 50 is directed towards the bottom of the base section 41.

[0084] In this invention, the spraying direction of the spraying section 50 is tilted downwards to spray fluid toward the bottom surface of the base section 41. The spraying section 50 sprays fluid downwards so that the fluid is kept as far away as possible from the wafer being cleaned by mega-acoustic cleaning, thereby reducing the impact of the sprayed fluid on the mega-acoustic cleaning process. This is because the fluid sprayed by the spraying section 50 is mainly used for overflow to rinse away the stripped particles, rather than cleaning the particles on the wafer surface through rinsing. This spraying angle of the spraying section 50 helps to ensure the effectiveness of the mega-acoustic cleaning.

[0085] Figure 6 This is a schematic diagram of a spraying section 50 provided in an embodiment of the present invention. The spraying section 50 includes at least a pair of spray pipes 51, which are disposed in the base section 41 of the inner tank 40 and spray cleaning liquid toward the inner side of the inner tank 40. The spray pipes 51 are provided with spray nozzles 51a, and there are multiple spray nozzles 51a, which are spaced apart along the length direction of the spray pipes 51.

[0086] Meanwhile, in order to control the splashing degree of the sprayed fluid in the spray section 50, adjacent spray nozzles 51a are spaced apart, and the spray nozzles 51a of adjacent nozzles 51 are staggered to reduce the collision and / or crossing of fluid inside the base section 41, and to control the degree of fluid disturbance as much as possible, so as to ensure that the fluid passing through the rectifier section 42 becomes relatively stable to a certain extent.

[0087] It is understood that the spray nozzle 51a can be a spray pipe, or a nozzle can be installed at the location of the spray nozzle 51a to supply cleaning fluid to a fixed point in the inner tank 40. In some embodiments, the nozzle installed at the spray nozzle 51a can be a columnar nozzle or a conical nozzle to disperse the sprayed fluid in the chamber of the base section 41.

[0088] Figure 7 This is a flow field diagram inside the circular cleaning device provided in an embodiment of the present invention, specifically showing the flow of the cleaning fluid in the inner tank 40. After the cleaning fluid in the base section 41 of the inner tank 40 is rectified by the rectifier section 42, its flow direction is generally vertically upward, so as to effectively reduce the disturbance and backflow of the fluid in the inner tank 40.

[0089] Specifically, the spray section 50 ( Figure 4 (As shown) The cleaning fluid sprayed toward the inner tank 40 flows vertically to push the particles stripped by the mega-sound cleaning upwards, and finally flows through the upper edge of the inner tank 40 to the space between the inner tank 40 and the housing 10.

[0090] Figure 8 This is a schematic diagram of a wafer cleaning apparatus 100 provided in another embodiment of the present invention, and... Figure 3 Compared to the illustrated embodiment, the structure of the inner tank 40 and the number of vibrating plates 30 in the wafer cleaning apparatus 100 are different.

[0091] Figure 9 yes Figure 8 The schematic diagram of the inner tank 40 shown in the embodiment illustrates that the wafer cleaning apparatus 100 is equipped with a pair of vibrating plates 30, which are symmetrically arranged on both sides of the inner tank 40. That is, the pair of vibrating plates 30 can clean the front and back sides of the wafer W respectively, realizing double-sided cleaning of the wafer.

[0092] The vibrating plate 30 is disposed between the rectifier section 42 and the shrinkage section 43. The vibrating plate 30 is inclined upward and outward from the upper end of the rectifier section 42, so that the high-frequency sound waves emitted by the vibrating plate 30 can propagate toward the surface of the wafer, so as to peel off the particles on the surface of the wafer under the action of cavitation and sound wave flow effects.

[0093] and Figure 4 Compared to the structure of the inner tank 40 shown, the contraction section 43 adopts a symmetrical structure. That is, a contraction structure is formed at the upper end of the inner tank 40. When the fluid in the inner tank 40 passes through the contraction structure, its flow velocity will be appropriately increased, and the cleaning liquid containing particulate matter can quickly overflow from the top of the inner tank 40.

[0094] Understandably, when only one side of the wafer requires mega-sound cleaning, this method can also be used. Figure 9 The symmetrical structure of the inner tank 40 shown ensures rapid overflow of the cleaning fluid, discharging the particles stripped by mega-acoustic cleaning between the inner tank 40 and the housing 10 via overflow. Specifically, the portion of the inner tank 40 above the rectifying section 42 also adopts a symmetrical structure relative to the vertical centerline. Depending on actual needs, a vibrating plate 30 is installed between the rectifying section 42 and the contraction section 43.

[0095] It should be noted that the tilt angle and performance parameters of the oscillating plates 30 set on the front and back of the wafer can be different to adapt to the characteristics of the front and back of the wafer and improve the effect of mega-acoustic cleaning.

[0096] Figure 10 yes Figure 8 The diagram shows the sound pressure intensity curve of the inner tank 40 of the wafer cleaning apparatus 100. The horizontal axis represents the vertical position of the wafer, specifically defined with the lower edge of the wafer as the zero point; the vertical axis represents the sound pressure at the corresponding position of the inner tank 40.

[0097] Figure 8 In this configuration, the vibrating plate 30 is positioned slightly below the central axis of the wafer, specifically within a coordinate range of 100mm-150mm. Figure 10 It can be seen that the intensity of the high-frequency sound waves emitted by the vibrating plate 30 did not decrease significantly, and the overall sound pressure of the inner groove 40 remained within a high range.

[0098] Figure 11 It is the mega-sound cleaning device in the existing technology ( Figure 1 The corresponding sound pressure intensity curve (shown) has the same meaning as the x-axis and y-axis. Figure 10The same applies. Because the mega-sound plate 20' is placed at the bottom of the cleaning tank 10', which is far from the wafer to be cleaned, the high-frequency sound waves emitted by the mega-sound plate 20' are attenuated significantly in the fluid, resulting in a reduction in the sound pressure intensity in the inner tank 40. This is not conducive to fully stripping particles from the wafer surface.

[0099] In this invention, the vibrating plate 30 is tilted and positioned slightly below the central axis of the wafer, which effectively reduces sound pressure attenuation and makes the overall sound pressure of the inner tank 40 higher, so as to obtain wafers with the required cleanliness.

[0100] The present invention also discloses a wafer post-processing apparatus, which includes the wafer cleaning device 100 described above. The wafer post-processing apparatus can operate independently of the CMP system, such as for post-CMP cleaning, or for wafer cleaning at other process nodes during wafer fabrication. The wafer post-processing apparatus further includes a wafer brush cleaning device and / or a wafer drying device to clean or dry the wafer surface to obtain wafers that meet process requirements.

[0101] The wafer cleaning device 100 provided by the present invention effectively solves the problems of attenuation of high-frequency sound waves emitted by the vibrating plate and overflow discharge in the traditional solution, and can effectively improve the cleaning effect of the wafer surface.

[0102] The wafer post-processing equipment described above can operate independently or be incorporated as a functional unit into a chemical mechanical polishing (CMP) system.

[0103] Figure 12 This is a schematic diagram of a chemical mechanical polishing system provided in an embodiment of the present invention. The chemical mechanical polishing system includes:

[0104] Front unit 1 is used to store wafers that are to be polished and those that have been polished and cleaned;

[0105] Polishing unit 2 is used for chemical mechanical polishing of wafers;

[0106] The cleaning unit 3 includes the wafer cleaning apparatus 100 described above.

[0107] Figure 12 In this system, the front-end unit 1 includes four sets of front-opening unified pods (FOUPs) for storing wafers. A front-mounted robotic arm is mounted on one side of each FOUP, used for wafer transfer between the front-end unit 1 and the cleaning unit 3. The robotic arm typically has two gripping jaws, one above the other, to respectively grasp finished wafers and wafers awaiting processing, preventing cross-contamination during wafer handling.

[0108] The cleaning unit 3 is located between the pre-processing unit 1 and the polishing unit 2. During wafer processing, firstly, the wafer is transferred from the pre-processing unit 1 to the polishing unit 2 for chemical mechanical polishing; then, the wafer is transferred to the cleaning unit 3 for cleaning and drying of the wafer surface; finally, the wafer is transferred back to the pre-processing unit 1. This process achieves material removal from the wafer in a "dry-in, dry-out" manner.

[0109] Cleaning unit 3 includes Figure 3 The wafer cleaning apparatus 100 shown removes particulate matter from the wafer surface using mega-sonic cleaning; the cleaning unit 3 typically also includes:

[0110] A roller brush cleaning device that removes particulate matter from the wafer surface by contact.

[0111] Vertical rotary drying or pull-out drying equipment, based on the Marangoni effect, peels off the water film on the wafer surface to achieve surface drying of the wafer;

[0112] The wafers with surface cleanliness that meet the requirements are obtained through the comprehensive processing of the cleaning unit 3.

[0113] Figure 12 In this invention, the wafer cleaning device 100 is disposed at the end of the cleaning unit 3. It can be understood that the process personnel can flexibly set the specific installation position of the wafer cleaning device 100 according to the process requirements.

[0114] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0115] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A wafer cleaning apparatus, characterized in that, include: Box; A support section, which is located in the housing, vertically supports the wafer to be cleaned; The vibrating plate is inclinedly arranged in the box to provide high-frequency vibration from the side; The spray section sprays fluid toward the inner tank formed by the vibrating plate to overflow and discharge the contaminants stripped off by high-frequency vibration from the top of the inner tank. The inner tank includes a base section, a rectifier section, and a contraction section. The base section is located at the bottom of the inner tank, the rectifier section is located at the top of the base section, the vibrating plate extends outward at an angle along the top of the rectifier section, and the contraction section extends inward at an angle along the top of the vibrating plate.

2. The wafer cleaning apparatus as described in claim 1, characterized in that, The inner groove is vertically arranged in the box, and the vibrating plate is arranged to the side of the vertical center line of the inner groove.

3. The wafer cleaning apparatus as described in claim 1, characterized in that, The horizontal distance between the rectifying section and the vertical centerline of the inner tank is less than the horizontal distance between the contraction section and the vertical centerline of the inner tank.

4. The wafer cleaning apparatus as described in claim 1, characterized in that, The spray section is located below the vibrating plate.

5. The wafer cleaning apparatus as described in claim 4, characterized in that, The support is located in the base section of the inner tank, and the spray section is located below the support.

6. The wafer cleaning apparatus as described in claim 4, characterized in that, The spray nozzle is disposed on the base section, and the spray nozzle is disposed at an angle downward so as to spray fluid toward the bottom of the base section.

7. The wafer cleaning apparatus as described in claim 1, characterized in that, The angle between the vibrating plate and the horizontal plane is 2-30°.

8. The wafer cleaning apparatus as described in claim 1, characterized in that, At least a portion of the vibrating plate is located below the central axis of the wafer to be cleaned.

9. The wafer cleaning apparatus as described in claim 1, characterized in that, The width of the vibrating plate is 10-50mm.

10. The wafer cleaning apparatus as described in claim 1, characterized in that, The number of the vibrating plates is one pair, which are symmetrically arranged on both sides of the inner groove.

11. A wafer post-processing equipment, characterized in that, Includes the wafer cleaning apparatus according to any one of claims 1 to 10.

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