Wafer backside cleaning device

Abstract

The utility model provides a kind of wafer back cleaning device, bernoulli chuck is used for non-contact bearing wafer;Rotary drive assembly includes connecting shaft and rotary motor, connecting shaft is connected bernoulli chuck and rotary motor respectively, protective cover is inverted circular table shape structure, protective cover is fixedly connected with the side surface of connecting shaft, the inside wall of protective cover constitutes the annular protection cavity of rotary motor;The upper end surface of protective cover is evenly distributed with multiple multi-nozzle assemblies, and the multi-nozzle assembly includes multiple nozzles, and the central axis of each nozzle is inclined to the normal direction of the back of wafer with angle.The utility model carries out enhanced cleaning to the edge part of wafer back, so that wafer back can be fully and effectively cleaned wafer back, while protective cover protects rotary motor from contacting waste liquid in cleaning process.

Description

Technical Field

[0001] This utility model relates to the field of wafer cleaning technology, and in particular to a wafer backside cleaning device. Background Technology

[0002] A wafer is a silicon wafer used to manufacture silicon semiconductor circuits; it is the basic material for making chips.

[0003] During the chip manufacturing process, metal residues and particulate impurities are generated on the back side and edge of the wafer. In order to ensure that the chip manufacturing has an ideal yield, special chemical cleaning agents are needed to remove metal residues and particulate impurities.

[0004] Existing wafer backside cleaning devices have a cleaning nozzle in the center. The cleaning agent is sprayed from the nozzle onto the back side of the wafer, with more cleaning liquid coming into contact with the center of the back side. The cleaning agent is thrown to the edge by centrifugal force alone. This method cannot guarantee that the cleaning agent will completely cover the entire uniform back side. This will result in an unsatisfactory cleaning effect on the back side of the wafer. Metal residues and particulate impurities that are not cleaned off on the back side of the wafer will still affect the yield of chip manufacturing. Utility Model Content

[0005] Based on the above description, this utility model provides a wafer backside cleaning device, which aims to solve the technical problems such as the easy residue on the backside edge of the wafer backside cleaning in the prior art.

[0006] A wafer backside cleaning apparatus includes a Bernoulli suction cup, a rotary drive assembly, a protective cover, and a multi-nozzle assembly;

[0007] Bernoulli chucks are used for non-contact wafer carrying;

[0008] The rotary drive assembly includes a connecting shaft and a rotary motor. The upper end of the connecting shaft is connected to a Bernoulli suction cup, and the lower end of the connecting shaft is connected to the output shaft of the rotary motor.

[0009] The protective cover has an inverted frustum-shaped structure. The protective cover is fixedly connected to the side of the connecting shaft, and the inner wall of the protective cover forms an annular protective cavity for the rotating motor.

[0010] Multiple multi-nozzle assemblies are evenly distributed around the upper surface of the protective cover. Each multi-nozzle assembly includes multiple nozzles, and the central axis of each nozzle forms an inclined angle with the normal direction of the back side of the wafer.

[0011] Furthermore, the multi-nozzle assembly includes a nozzle seat and multiple nozzles fixed on the nozzle seat;

[0012] The upper surface of the protective cover has connecting seats evenly distributed around its circumference. The connecting seats are used for detachable connection with the nozzle seat.

[0013] Furthermore, the upper end face of the nozzle seat is provided with at least two mounting inclined surfaces with different inclination angles, and at least one nozzle is provided on each mounting inclined surface, and the central axis of the nozzle provided on the mounting inclined surface is perpendicular to the mounting inclined surface.

[0014] Furthermore, the projections of the nozzles in the multi-nozzle assembly onto the horizontal plane are distributed radially outward along the wafer.

[0015] Furthermore, the nozzle seat is provided with a first mounting inclined surface and a second mounting inclined surface; wherein, the angle between the first mounting inclined surface and the horizontal plane is smaller than the angle between the second mounting inclined surface and the horizontal plane;

[0016] The projection of the first mounting inclined surface onto the horizontal plane is closer to the center of the protective cover than the projection of the second mounting inclined surface onto the horizontal plane.

[0017] Furthermore, at least two sides of the connector are provided with notches, and the notches are provided with first mounting holes;

[0018] The bottom edge of the nozzle seat is provided with a positioning boss that matches the notch, and the positioning boss has a second mounting hole that is coaxial with the first mounting hole;

[0019] The nozzle seat and the connecting seat are detachably connected by the first and second mounting holes through which fasteners pass.

[0020] Furthermore, the bottom edge of the protective cover is connected to the leak-proof side ring, forming an upward-opening annular leak-proof groove between the inner wall of the leak-proof side ring and the outer wall of the protective cover. The inner diameter of the leak-proof side ring is larger than the diameter of the wafer.

[0021] Furthermore, the height of the inner wall of the leak-proof side ring exceeds the height of the outer wall of the protective cover.

[0022] Furthermore, the bottom of the annular anti-leakage groove is provided with at least one leakage hole, which is used to connect to a leakage pipe.

[0023] Furthermore, a fluid channel is provided inside the nozzle seat. One end of the fluid channel is connected to the nozzle, and the other end serves as a flow channel inlet with a fluid inlet connector. The fluid inlet connector is connected to a fluid delivery pipe that delivers fluid to the nozzle.

[0024] At least one nozzle on the nozzle holder is equipped with an independent fluid input connector and an independent fluid channel.

[0025] The beneficial technical effects of this utility model are as follows: By setting a protective cover and nozzles around the protective cover, with the nozzles pointing towards the edge of the back side of the wafer, the cleaning agent is delivered to enhance the cleaning of the edge of the back side of the wafer. Alternatively, air can be sprayed to blow away cleaning residues on the back side of the wafer, enabling a comprehensive and effective cleaning of the back side of the wafer. At the same time, the structure is simple, easy to replace, and the protective cover also protects the motor from contact with waste liquid generated during the cleaning process. Attached Figure Description

[0026] Figure 1 This is a side view of one embodiment of the wafer backside cleaning device of this utility model.

[0027] Figure 2 This is a three-dimensional structural schematic diagram of one embodiment of a wafer backside cleaning device according to the present invention;

[0028] Figure 3 This is a side view of the multi-nozzle assembly of a wafer backside cleaning device according to the present invention.

[0029] Figure 4 This is a front view of the multi-nozzle assembly of a wafer backside cleaning device according to the present invention.

[0030] Figure 5 This is a cross-sectional structural diagram of a multi-nozzle assembly of a wafer backside cleaning device according to the present invention;

[0031] Figure 6 This is an exploded structural diagram of another embodiment of the wafer backside cleaning device of this utility model;

[0032] Figure 7 This is a schematic diagram of the combined structure of another embodiment of the wafer backside cleaning device of this utility model;

[0033] Figure 8-9 This is a schematic diagram of a wafer backside cleaning device according to another embodiment of the present invention, taken from different side angles.

[0034] Figure 10 This is a schematic diagram of the pipe layout structure of a multi-nozzle assembly in a wafer backside cleaning device according to the present invention.

[0035] in:

[0036] 1-Bernoulli chuck; 2-Wafer; 3-Nozzle; 4-Nozzle seat; 41-Flow channel inlet; 42-Second mounting hole on the left / right side positioning boss; 43-Second mounting hole on the front side positioning boss; 5-Connecting shaft; 6-Protective cover; 7-Connecting seat; 8-Annular anti-leak groove; 9-Anti-leak side ring; 10-Bent pipe; 11-Intermediate connection; 12-Leakage connector; 13-Leakage pipe; 14-Fluid input connector. Detailed Implementation

[0037] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0038] It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0039] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but this is not intended to limit the present invention.

[0040] like Figures 1-2 As shown, this utility model provides a wafer backside cleaning device, including a Bernoulli suction cup 1, a rotary drive assembly, a protective cover 6, and a multi-nozzle assembly;

[0041] Bernoulli chuck 1 is used for non-contact support of wafer 2;

[0042] The rotary drive assembly includes a connecting shaft 5 and a rotary motor. The upper end of the connecting shaft 5 is connected to the Bernoulli suction cup 1, and the lower end of the connecting shaft 5 is connected to the output shaft of the rotary motor.

[0043] The protective cover 6 has an inverted frustum-shaped structure. The protective cover 6 is fixedly connected to the side of the connecting shaft 5. The inner wall of the protective cover 6 forms an annular protective cavity for the rotating motor.

[0044] Multiple multi-nozzle assemblies are evenly distributed around the upper surface of the protective cover 6. Each multi-nozzle assembly includes multiple nozzles 3, and the central axis of each nozzle 3 forms an inclined angle with the normal direction of the back side of the wafer 2.

[0045] The Bernoulli chuck 1 is configured to suspend and support the wafer through the gas static pressure effect, i.e., non-contact wafer support. The adsorption surface of the Bernoulli chuck is provided with uniformly distributed gas guide grooves, which is existing technology and will not be described in detail here.

[0046] The upper end of the connecting shaft 5 is rigidly connected to the central area of ​​the Bernoulli suction cup 1 so as to drive the Bernoulli suction cup 1 to rotate.

[0047] This invention features a protective cover 6 with nozzles 3 positioned around its perimeter, pointing towards the edge of the back side of the wafer 2. By delivering cleaning agent, it enhances the cleaning of the edge of the back side of the wafer 2, providing an additional chemical cleaning option for the back side of the wafer 2. It can also blow away cleaning residues from the back side of the wafer 2 using ejected gas, enabling a comprehensive and effective cleaning of the back side of the wafer 2. Simultaneously, the protective cover 6 protects the rotary motor from contact with waste liquid generated during the cleaning process.

[0048] The protective cover 6 has an inverted frustum-shaped structure, including a downwardly sloping upper surface and an outer side wall. The inner side wall forms an annular protective cavity for the rotating motor, serving as a splash-proof device to protect the rotating motor from liquid spillage. As the wafer 2 rotates, the sprayed liquid is flung outwards due to centrifugal force. Even if the liquid flows down the outer side wall of the protective cover 6, it will still flow into the drain tank along the protective cover 6. The protective cover 6 protects the rotating motor from being intruded by waste liquid.

[0049] Furthermore, the multi-nozzle assembly includes a nozzle seat 4 and a plurality of nozzles 3 fixed on the nozzle seat 4;

[0050] The upper surface of the protective cover 6 is evenly distributed with connecting seats 7, which are used for detachable connection with the nozzle seat 4.

[0051] Each multi-nozzle assembly consists of a nozzle seat 4 and a nozzle 3. The nozzle 3 is threadedly mounted on the nozzle seat 4, and the nozzle seat 4 is detachably mounted on the connecting seat 7 of the protective cover 6. The nozzle 3 and the nozzle seat 4 can be replaced at any time according to the working conditions. Each nozzle 3 is independently fixed to the nozzle seat 4, and the nozzles 3 can be made to not interfere with each other.

[0052] The nozzle 3 and nozzle seat 4 of this utility model can be replaced as needed at any time. They can be replaced as a whole or individually, which brings convenience to the installation.

[0053] The nozzle 3 of this invention is set at an angle, and the effect of angled spraying is that there will be vertical and horizontal force components, which is more conducive to clearing the residue on the wafer surface.

[0054] Specifically, at least two multi-nozzle assemblies are evenly arranged on the circumferential surface of the upper end face of the protective cover 6, which can be configured with liquid medicine as needed.

[0055] like Figure 1 As shown, furthermore, in the multi-nozzle assembly, at least two nozzles 3 have different tilt angles between their central axes and the normal direction on the back side of the wafer 2.

[0056] like Figures 3-5As shown, further, the upper end face of the nozzle seat 4 is provided with at least two mounting inclined surfaces with different inclination angles, and at least one nozzle 3 is provided on each mounting inclined surface, and the central axis of the nozzle 3 provided on the mounting inclined surface is perpendicular to the mounting inclined surface.

[0057] Furthermore, the projection of nozzle 3 in the multi-nozzle assembly onto the horizontal plane is distributed radially outward along the wafer 2.

[0058] Furthermore, the nozzle seat 4 is provided with a first mounting inclined surface and a second mounting inclined surface;

[0059] Wherein, the angle between the first mounting inclined surface and the horizontal plane is smaller than the angle between the second mounting inclined surface and the horizontal plane;

[0060] The projection of the first mounting inclined surface onto the horizontal plane is closer to the center of the protective cover 6 than the projection of the second mounting inclined surface onto the horizontal plane.

[0061] Nozzle 3 sprays fluid along its central axis. Although the angle at which the fluid is sprayed from nozzle 3 is fixed, nozzle seats 4 with different tilt angles can be designed. This results in different tilt angles between the central axis of nozzle 3 and the normal direction of the back surface of wafer 2 on different tilt surfaces, thereby controlling the angle at which the liquid is sprayed from the nozzle. Utilizing the principle of different tilt angles of the mounting surfaces, the nozzle spray angle can be determined without the need for a waist-shaped adjustment hole, leading to higher cleaning stability. If a different tilt angle mode is required, simply replace the nozzle seat with one that has a different tilt angle; replacement is convenient and requires no manual adjustment.

[0062] Specifically, a nozzle is positioned on the mounting inclined surface closer to the central axis of the protective cover 6 to form an inner ring nozzle, and two nozzles are positioned on the other mounting inclined surface to form an outer ring nozzle. This results in the projection of the nozzles 3 in the multi-nozzle assembly onto the horizontal plane in a radial outward distribution along the wafer 2.

[0063] Specifically, the outer ring nozzles spray cleaning fluid, while the inner ring nozzles can spray nitrogen gas. Since the spraying cleans from the center outwards, the two nozzles on the outer ring spray cleaning fluid, and the one nozzle on the inner ring sprays nitrogen gas. The cleaning fluid and nitrogen gas can coexist, thereby reducing water residue at the edges and improving cleaning quality.

[0064] Specifically, of the two mounting inclined surfaces with different tilt angles, the mounting inclined surface closer to the central axis of the protective cover 6 has an acute angle of inclination of 16 degrees relative to the horizontal plane, while the other mounting inclined surface has an acute angle of inclination of 30 degrees relative to the horizontal plane.

[0065] Preferably, the nozzle 3 is a pointed nozzle with a central channel diameter of 3 mm. The channel diameter of the nozzle 3 is smaller than the diameter of the liquid inlet channel.

[0066] Furthermore, at least two sides of the connector 7 are provided with notches, and the notches are provided with first mounting holes;

[0067] The bottom edge of the nozzle seat 4 is provided with a positioning boss that matches the notch, and the positioning boss has a second mounting hole that is coaxial with the first mounting hole;

[0068] The nozzle seat 4 and the connecting seat 7 are detachably connected by fasteners passing through the first and second mounting holes.

[0069] The first mounting hole can be a threaded hole, and the fastener is a screw. The fastener passes through the second mounting hole on the positioning boss for threaded installation.

[0070] Specifically, such as Figure 3 and Figure 4 As shown, notches are provided on the left and right sides of the upper surface of the connecting seat 7. The left and right sides of the upper surface of the bottom surface of the nozzle seat 4 are provided with positioning bosses. The positioning boss on the left side and the positioning boss on the right side are respectively provided with a second mounting hole, namely the second mounting hole 42 on the left / right positioning boss.

[0071] Specifically, such as Figure 5 As shown, the front side of the upper end face of the connecting seat 7 is provided with notches. The front side of the upper end face of the bottom surface of the nozzle seat 4 has a positioning boss, and the positioning boss on the front side is provided with a second mounting hole, namely the second mounting hole 43 on the positioning boss on the front side.

[0072] like Figure 6 , Figure 7 As shown, in another embodiment of the present invention, the bottom edge of the protective cover 6 is connected to the leak-proof side ring 9, so that an upward-opening annular leak-proof groove 8 is formed between the inner side wall of the leak-proof side ring 9 and the outer side wall of the protective cover 6, and the inner diameter of the leak-proof side ring 9 is larger than the diameter of the wafer 2.

[0073] The annular anti-leak groove 8, which is composed of the protective cover 6 and the anti-leak side ring 9, serves as an anti-splash device to prevent liquid from flowing onto other components and causing corrosion.

[0074] Furthermore, the height of the inner wall of the leak-proof side ring 9 exceeds the height of the outer wall of the protective cover 6.

[0075] The inner wall of the leak-proof side ring 9 is relatively high, forming a deep annular leak-proof groove 8 to minimize the leakage of waste liquid.

[0076] like Figures 8-9As shown, the bottom of the annular anti-leakage groove 8 is provided with at least one leakage hole, which is used to connect with the leakage pipe 13.

[0077] Liquid flows into the annular leak-proof groove 8 through the protective cover 6. A leak connector 12 is installed at the leak hole in the annular leak-proof groove 8. The leak connector 12 drains the waste liquid through the connected leak pipe 13, preventing it from accumulating in the annular leak-proof groove 8 and causing it to overflow.

[0078] like Figure 10 As shown, further, a fluid channel is provided inside the nozzle seat 4. One end of the fluid channel is connected to the nozzle 3 and the other end is provided with a fluid input connector 14 as a flow channel inlet. The fluid input connector 14 is connected to a fluid delivery pipe that delivers fluid to the nozzle 3.

[0079] At least one nozzle 3 on the nozzle seat 4 is equipped with an independent fluid input connector and an independent fluid channel, which is not connected to the fluid channels of the other nozzles 3.

[0080] The flow channel inlet is located on the side of the nozzle seat 4.

[0081] The bottom of the annular anti-leakage groove 8 is provided with a connection hole, and the connection hole is provided with an intermediate connector 11. The fluid input connector 14 is connected to the intermediate connector 11 through the curved pipe 10. The intermediate connector 11 is also connected to the fluid delivery pipe. The externally input fluid passes through the fluid delivery pipe, the intermediate connector, the curved pipe, and the fluid input connector 14 in sequence before entering the fluid channel of the nozzle seat 4, and finally is sprayed onto the back side of the wafer by the nozzle 3.

[0082] The above description is only a preferred embodiment of the present utility model and does not limit the implementation method and protection scope of the present utility model. Those skilled in the art should realize that all solutions obtained by equivalent substitutions and obvious changes made based on the description and illustrations of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A wafer backside cleaning apparatus, characterized in that, Includes Bernoulli suction cup, rotary drive assembly, protective cover and multi-nozzle assembly; The Bernoulli chuck is used for non-contact wafer carrying; The rotary drive assembly includes a connecting shaft and a rotary motor. The upper end of the connecting shaft is connected to the Bernoulli suction cup, and the lower end of the connecting shaft is connected to the output shaft of the rotary motor. The protective cover has an inverted frustum-shaped structure. The protective cover is fixedly connected to the side of the connecting shaft. The inner wall of the protective cover forms an annular protective cavity for the rotary motor. The upper surface of the protective cover has a plurality of multi-nozzle assemblies evenly distributed around its circumference. Each multi-nozzle assembly includes a plurality of nozzles, and the central axis of each nozzle forms an inclined angle with the normal direction of the back side of the wafer.

2. The wafer backside cleaning apparatus as described in claim 1, characterized in that, The multi-nozzle assembly includes a nozzle seat and a plurality of nozzles fixed on the nozzle seat; The upper surface of the protective cover is evenly distributed with connecting seats in the circumference, and the connecting seats are used for detachable connection with the nozzle seat.

3. The wafer backside cleaning apparatus as described in claim 2, characterized in that, The upper end face of the nozzle seat is provided with at least two mounting inclined surfaces with different inclination angles. At least one nozzle is provided on each mounting inclined surface, and the central axis of the nozzle provided on the mounting inclined surface is perpendicular to the mounting inclined surface.

4. The wafer backside cleaning apparatus as described in claim 2, characterized in that, The projections of the nozzles in the multi-nozzle assembly onto the horizontal plane are distributed radially outward along the wafer.

5. The wafer backside cleaning apparatus as described in claim 3, characterized in that, The nozzle seat is provided with a first mounting inclined surface and a second mounting inclined surface; Wherein, the angle between the first mounting inclined surface and the horizontal plane is smaller than the angle between the second mounting inclined surface and the horizontal plane; The projection of the first mounting inclined surface onto the horizontal plane is closer to the center of the protective cover than the projection of the second mounting inclined surface onto the horizontal plane.

6. The wafer backside cleaning apparatus as described in claim 2, characterized in that, The connector has notches on at least two sides, and each notch has a first mounting hole. The bottom edge of the nozzle seat is provided with a positioning boss that matches the notch, and the positioning boss has a second mounting hole that is coaxial with the first mounting hole. The nozzle seat and the connecting seat are detachably connected by fasteners passing through the first mounting hole and the second mounting hole.

7. The wafer backside cleaning apparatus as described in claim 1, characterized in that, The bottom edge of the protective cover is connected to the leak-proof side ring, forming an upward-opening annular leak-proof groove between the inner wall of the leak-proof side ring and the outer wall of the protective cover. The inner diameter of the leak-proof side ring is larger than the diameter of the wafer.

8. The wafer backside cleaning apparatus as described in claim 7, characterized in that, The height of the inner wall of the leak-proof side ring exceeds the height of the outer wall of the protective cover.

9. A wafer backside cleaning apparatus as described in claim 7, characterized in that, The bottom of the annular anti-leakage groove is provided with at least one leakage hole, which is used to connect to a leakage pipe.

10. A wafer backside cleaning apparatus as described in claim 2, characterized in that, The nozzle seat is provided with a fluid channel inside. One end of the fluid channel is connected to the nozzle and the other end is provided with a fluid input connector as a flow channel inlet. The fluid input connector is connected to a fluid delivery pipe that delivers fluid to the nozzle. At least one nozzle on the nozzle seat is equipped with an independent fluid input connector and an independent fluid channel.

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