Wafer post-processing device and method

Abstract

The invention discloses a wafer post-processing device and a wafer post-processing method. The wafer post-processing device comprises a box body; the clamping driving assembly is arranged on the back plate of the box body so as to vertically clamp and drive the wafer to rotate; the supply arm is arranged in the box body, and the supply arm vertically swings and supplies fluid to the wafer through a spraying assembly at the free end of the supply arm; the spraying assembly comprises a first liquid spraying rod and a second liquid spraying rod, wherein the falling point of the first liquid spraying rod skims over the center of the wafer; a drop point of the dry gas spray rod is located on a boundary line of a three-phase boundary formed by the liquid, the air and the wafer; the falling point of the second liquid spraying rod is positioned obliquely above the center of the wafer, and the spraying direction of the second liquid spraying rod conforms to the rotating direction of the wafer.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of semiconductor manufacturing technology, and in particular, to a wafer post-treatment device and method. Background Art

[0002] The integrated circuit industry is the core of the information technology industry and plays a key role in boosting the transformation and upgrading of the manufacturing industry to digital and intelligent. A chip is the carrier of an integrated circuit, and chip manufacturing involves integrated circuit design, wafer manufacturing, wafer processing, electrical measurement, cutting and packaging, and testing processes. Among them, chemical mechanical polishing is one of the five core processes in wafer manufacturing.

[0003] The wafers that have completed chemical mechanical polishing need to be post-treated such as cleaned and dried to avoid the contamination of semiconductor devices by trace ions and metal particles and ensure the performance and qualification rate of semiconductor devices. It is crucial to avoid the formation of liquid marks during the drying process. The wettability of the wafer has a significant impact on the formation of liquid marks, and it is more likely to generate liquid marks on a hydrophobic surface because the liquid film on the hydrophobic film is easily broken into isolated droplets and its evaporation in oxygen-containing air will induce liquid marks.

[0004] Compared with traditional spin rinse dry (SRD), due to its excellent performance in eliminating liquid mark defects, wafer drying based on the Marangoni (also known as "Marangoni" or "Marangoni") effect has received extensive attention. The Marangoni effect is an interfacial convection phenomenon caused by a surface tension gradient. The existing Marangoni effect-based drying technology is that when a wafer is taken out of a deionized water bath, organic vapors such as isopropyl alcohol (IPA) are blown onto the "meniscus" formed by the wafer-air-liquid, and the induced Marangoni effect realizes the reflux of the attached liquid, thereby obtaining a completely dried wafer.

[0005] During Marangoni drying, usually a high-flow rinsing agent (such as deionized water) is first sprayed onto the wafer for rinsing to remove the residual chemical liquid and suspended particles in the liquid film on the wafer surface after the previous post-cleaning module process treatment, and then Marangoni drying is carried out, and then spin drying. The specific operation steps are as follows.

[0006] Step 1: Loading the wafer. The swing spraying mechanism is in Figure 1 the horizontal position therein, and the robot outside the device places the wafer on the wafer clamping mechanism, and the wafer is clamped;

[0007] Step 2: Rinsing. The swinging spray mechanism swings to a position where the spraying landing point of the Marangoni liquid spray bar is exactly opposite the center of the wafer and remains fixed. At this time, a spray bar with spray holes arranged roughly along the radius direction of the wafer can be supplemented. The Marangoni liquid spray bar and the spray bar simultaneously spray a high flow rate of rinsing agent, and the wafer rotates at a high speed;

[0008] Step 3: Marangoni drying. The wafer rotates at a medium speed, and the swinging spray mechanism swings from the position described in Step 2 to the horizontal position at a certain speed. At the same time, drying gas is sprayed through the gas spray bar and rinsing agent is sprayed through the Marangoni liquid spray bar for Marangoni drying;

[0009] Step 4: High-speed rotation for spin-drying. The swinging spray mechanism remains in the horizontal position, stops spraying the rinsing agent, and the wafer rotates at a high speed to spin-dry the residual water on the back;

[0010] Step 5: Wafer picking. The swinging spray mechanism remains in the horizontal position, the wafer clamping mechanism is in a non-clamping state, and an external manipulator takes out the wafer from the wafer post-processing device.

[0011] The existing rotary drying module has certain limitations in the rinsing step: it is impossible to use a high flow rate of rinsing agent and a high wafer rotation speed simultaneously, resulting in the inability to further improve the rinsing efficiency. The specific reasons are as follows:

[0012] Due to functional positioning, the Marangoni liquid spray bar is suitable for using a small inner diameter nozzle. If only the Marangoni liquid spray bar is used to spray the rinsing agent in the rinsing step, its flow rate is limited (for example, less than 300 ml / min). For a hydrophobic wafer liquid film, it is not sufficient to fully cover the entire surface, resulting in poor rinsing effect at the outer part of the wafer radius. As Figure 2 shown, except for a complete water film near the center of the wafer, the liquid film at the outer part of the radius breaks to form discrete water flows. If forced to spray beyond the limit, the sprayed liquid flow enters a turbulent state, causing a large amount of sputtering and splashing to wet the box environment such as the gas spray bar, affecting the subsequent drying effect.

[0013] If a radial spray bar is supplemented to spray the rinsing agent simultaneously in the rinsing step, the wafer rotation speed is limited (for example, less than 500 rpm). If forced to exceed the limit, significant liquid sputtering occurs near the spraying landing point of the radial spray bar in the outer region of the wafer radius (such as a radius greater than 50 mm) (the reason is that there is a large speed difference between the newly sprayed liquid flow and the liquid flow rotating with the wafer surface here, and the mutual impact causes sputtering), which can wet the box environment such as the gas spray bar and affect the subsequent drying effect. Summary of the Invention

[0014] In view of this, the embodiments of the present application provide a wafer post-processing device and method to at least partially solve the above problems.

[0015] According to the first aspect of the embodiments of the present application, a wafer post-processing device is provided for vertically rotating and drying a wafer based on the Marangoni effect, which includes:

[0016] A box body;

[0017] A clamping and driving assembly, which is arranged on the back plate of the box body to vertically clamp and drive the wafer to rotate;

[0018] A supply arm, which is arranged in the box body. The supply arm swings vertically and supplies fluid to the wafer through a spraying assembly at its free end;

[0019] The spraying assembly includes:

[0020] A first liquid spraying rod, the landing point of which skims over the center of the wafer;

[0021] A drying gas spraying rod, the landing point of which is located on the boundary line of the three-phase junction formed by the liquid, air and the wafer;

[0022] A second liquid spraying rod, the landing point of which is located obliquely above the center of the wafer and the spraying direction conforms to the rotation direction of the wafer.

[0023] In some embodiments, the landing point of the second liquid spraying rod is located above the left or right of the center of the wafer, and the rinsing liquid sprayed covers the outer area of the wafer.

[0024] In some embodiments, the liquid sprayed by the first liquid spraying rod covers the central area of the wafer, and there is an overlapping part between it and the outer area; the overlapping part is an annular area concentric with the wafer.

[0025] In some embodiments, the radial dimension of the overlapping part is less than or equal to 1 / 3 of the radius of the wafer

[0026] In some embodiments, the spraying rod of the spraying assembly is a single landing point spraying rod, which is arranged along the length direction of the supply arm.

[0027] In some embodiments, the inner diameter of the nozzle of the second liquid spraying rod is larger than the inner diameter of the nozzle of the first liquid spraying rod.

[0028] In some embodiments, the distance between the nozzle of the second liquid spraying rod and the liquid landing surface is equal to the distance between the nozzle of the first liquid spraying rod and the liquid landing surface.

[0029] In some embodiments, the end of the first liquid spraying rod is bent inward to form a spraying end, and the angle between the spraying end and the rod body of the first liquid spraying rod is 40-90°.

[0030] In some embodiments, the end of the second liquid spraying rod is bent inward to form a spraying end, and the angle between the spraying end and the rod body of the second liquid spraying rod is 90-140°.

[0031] In some embodiments, the end of the dry gas spray bar is bent inward to form a spray head, and the angle between the spray head and the body of the dry gas spray bar is 70 to 110°.

[0032] In some embodiments, the fluid ejected by the first liquid spray bar conforms to the rotation direction of the wafer, and the angle between the plane where the first liquid spray bar is located and the liquid falling surface is 45 to 85°.

[0033] In some embodiments, the fluid ejected by the second liquid spray bar intersects with the fluid ejected by the first liquid spray bar, and the angle between the plane where the second liquid spray bar is located and the liquid falling surface is 45 to 85°.

[0034] According to the second aspect of the embodiments of the present application, a wafer post-treatment method is provided, which uses the wafer post-treatment device described above, including:

[0035] S1, placing the wafer on the clamping part of the clamping and driving assembly, and closing the clamping part to vertically clamp the wafer;

[0036] S2, the supply arm swings to the rinsing position, and the first liquid spray bar and the second liquid spray bar spray rinsing liquid towards the rotating wafer;

[0037] S3, during the process that the supply arm swings from the rinsing position to the standby position, the dry gas spray bar sprays dry gas, and the first liquid spray bar sprays rinsing liquid;

[0038] S4, the supply arm remains at the standby position, and the wafer rotates at a high speed to spin-dry the liquid remaining on the back of the wafer;

[0039] S5, opening the clamping part of the clamping and driving assembly to take away the wafer after the post-treatment is completed.

[0040] In some embodiments, the spraying flow rate of the second liquid spray bar is greater than that of the first liquid spray bar.

[0041] In some embodiments, the spraying flow rate of the first liquid spray bar is 50 to 300 mL / min, and the spraying flow rate of the second liquid spray bar is 200 to 1000 mL / min.

[0042] Further, in step S2, the rotation speed of the wafer is 900 to 2500 rpm; in step S3, the rotation speed of the wafer is 100 to 2000 rpm.

[0043] In some embodiments, the distance between the landing point of the second liquid spray bar and the center of the wafer is 25 to 50 mm.

[0044] Further, in step S2, the distance between the nozzle of the second liquid spray bar and the surface of the wafer is 4 to 20 mm.

[0045] Further, in step S3, the second liquid spraying rod stops supplying the rinsing liquid.

[0046] In some embodiments, when the supply arm is in the rinsing position, the nozzle of the first liquid spraying rod faces the center of the wafer to be processed; when the supply arm is in the standby position, the supply arm is in a horizontal position.

[0047] In some embodiments, the rinsing liquid is deionized water, or deionized water containing carbon dioxide.

[0048] The beneficial effects of the present invention include:

[0049] a. The provided wafer post-processing device is configured with a first liquid spraying rod and a second liquid spraying rod, and the two are combined to spray the rinsing liquid to adapt to the working conditions of large flow rate and high rotation speed, significantly improving the rinsing efficiency of the wafer to efficiently remove the chemical liquid and suspended particles remaining on the surface liquid film of the wafer;

[0050] b. The landing points of the rinsing liquid sprayed by the first liquid spraying rod and the second liquid spraying rod are different, effectively avoiding the sputtering caused by the collision of two liquid flows due to proximity;

[0051] c. There is an annular overlapping area between the central area formed by the rinsing liquid sprayed by the first liquid spraying rod and the outer area formed by the rinsing liquid sprayed by the second liquid spraying rod to ensure that the rinsing liquid completely covers the surface of the wafer W, thereby ensuring the rinsing effect of the wafer;

[0052] d. During the wafer rinsing process, the distance between the landing point P of the second liquid spraying rod and the landing point O of the first liquid spraying rod is relatively close. Even if the rotation speed of the wafer is increased to 900 - 2500 rpm, the linear velocity at the landing point P is not high, avoiding excessive linear velocity of the liquid on the wafer surface and causing sputtering;

[0053] e. During the wafer rinsing process, the spraying direction of the second liquid spraying rod conforms to the rotation direction of the wafer, and the sprayed rinsing liquid flows along the rotation direction of the wafer. The liquid sprayed by the first spraying rod also flows along the direction of the wafer under the action of centrifugal force and gravity. The velocity difference between the two is small, and even if the flow rate of the second liquid spraying rod 52 is large, it will not cause sputtering due to the impact of the liquid flow, thereby ensuring the rinsing effect of the wafer;

[0054] f. The distance between the nozzle of the second liquid spraying rod and the wafer surface is 4 - 20 mm. The distance between the nozzle of the second liquid spraying rod and the wafer surface should not be too large to prevent the sprayed liquid flow from being interfered by gravity and affecting the accuracy of the liquid spraying landing point;

[0055] g. The fluid ejected from the first liquid ejection rod conforms to the rotation direction of the wafer, and the angle between the plane where the first liquid ejection rod is located and the liquid falling surface is 45 to 85°; with such a setting, the ejected liquid flow has a velocity component that conforms to the direction of the linear velocity of the solid surface of the wafer, so that the liquid flow can fall on the wafer surface more smoothly, which is beneficial to stabilizing the liquid film on the wafer surface and improving the Marangoni drying effect;

[0056] h. The angle between the plane where the second liquid ejection rod is located and the liquid falling surface is 45 to 85°, and its nozzle is inclined upward, so as to stagger the landing position of the first liquid ejection rod and form an ejected liquid flow that conforms to the liquid flow direction on the wafer surface, so as to control the liquid ejection landing points of the two and prevent the ejected liquid flows from colliding with each other and causing sputtering;

[0057] i. Deionized water containing carbon dioxide can improve the conductivity of deionized water, so as to reduce the defects caused by static electricity on the wafer surface and improve the post-treatment effect of the wafer. Description of the Drawings

[0058] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments recorded in the embodiments of the present application. For those of ordinary skill in the art, other drawings can also be obtained according to these drawings.

[0059] Figure 1 is a schematic diagram of a wafer post-treatment device in the prior art;

[0060] Figure 2 is a schematic diagram of the rinsing effect in the prior art;

[0061] Figure 3 is a schematic diagram of a wafer post-treatment device provided by an embodiment of the present invention;

[0062] Figure 4 is a schematic diagram of the supply arm swinging to the rinsing position provided by an embodiment of the present invention;

[0063] Figure 5 is Figure 4 a partial enlarged view of part A in

[0064] Figure 6 is a distribution diagram of the rinsing liquid on the wafer surface when the wafer post-treatment device performs rinsing;

[0065] Figure 7 is a schematic diagram of the supply arm swinging to the central position of the rotating wafer W provided by an embodiment of the present invention;

[0066] Figure 8 is Figure 7 a schematic diagram of each spray rod in the embodiment;

[0067] Figure 9 It is a schematic diagram of the spraying assembly on the supply arm relative to the wafer provided by an embodiment of the present invention;

[0068] Figure 10 It is a schematic diagram of a wafer post-processing device provided by another embodiment of the present invention;

[0069] Figure 11 It is a flowchart of a wafer post-processing method provided by an embodiment of the present invention. Detailed implementation manners

[0070] In order to enable those skilled in the art to better understand the technical solutions in the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art shall fall within the scope of protection of the embodiments of the present application.

[0071] The terms used in the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. The singular forms of "a", "the" and "said" used in the present application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more of the associated listed items.

[0072] It should be understood that although the terms "first", "second", "third", etc. may be used in the present application to describe various information, such information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of the present application, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present application, "a plurality" means two or more unless otherwise specifically defined.

[0073] Figure 3 It is a schematic diagram of a wafer post-processing device 100 provided by an embodiment of the present invention, which is used for vertical rotation drying of wafers based on the Marangoni effect. The wafer post-processing device 100 includes:

[0074] A box body 10, which provides a relatively sealed chamber for wafer post-processing; specifically, a switch door is usually configured at the top of the box body 10 to facilitate an external manipulator to pick and place wafers from the inside of the box body 10;

[0075] The clamping drive assembly 20 is disposed on the back panel of the box body 10 to vertically clamp and drive the wafer to rotate. Specifically, the wafer drive assembly 20 includes a turntable 21, and a plurality of chucks 22 are arranged on the outer peripheral side of the turntable 21 to vertically clamp the wafer. A turntable rotation motor is arranged on the back side of the turntable 21 to drive the wafer on the turntable 21 to rotate.

[0076] The supply arm 30 is disposed in the box body 10. The supply arm 30 is connected to the rotating shaft 40, and the rotating shaft 40 is perpendicularly arranged to the back panel of the box body 10 and is located outside the clamping drive assembly 20. The supply arm 30 can swing around the rotating shaft 40 in the vertical direction under the action of a swing motor to change the position of the spraying assembly 50 at the free end (the other end) of the supply arm 30. The spraying assembly 50 can swing along with the supply arm 30 to supply fluid to the entire surface of the rotating wafer W, thereby realizing the surface cleaning and drying of the wafer.

[0077] It should be noted that the specific implementation manners and specific embodiments of the present application are described and illustrated when the wafer post-processing device 100 according to the present application is in a stationary non-operating state. In this state, the supply arm 30 is generally in a horizontal position, but this does not mean that the wafer post-processing device 100 according to the embodiments of the present application cannot operate, nor does it mean that the supply arm 30 is fixedly immovable.

[0078] Figure 3 In the illustrated embodiment, the spraying assembly 50 includes a first liquid spraying rod 51, a second liquid spraying rod 52, and a drying gas spraying rod 53. The sprayed fluid realizes the drying of the wafer W by means of centrifugal force and the Marangoni Effect, and completely strips the rinsing liquid sprayed on the surface of the wafer W to achieve the complete drying of the wafer.

[0079] Specifically, the first liquid spraying rod 51 supplies rinsing liquid towards the surface of the wafer to realize the rinsing of the wafer. In order to supply fluid to the entire surface of the wafer W, the first liquid spraying rod 51 is arranged to be able to pass over the center O of the wafer during the movement along with the supply arm 30, that is, from the direction perpendicular to the plane where the wafer is located, the liquid dropping point of the first liquid spraying rod 51 can pass through the center of the wafer (at the center point) during the movement, so that the first liquid spraying rod 51 can supply fluid to the entire surface of the wafer except for the part covered by the chucks 22 on one side of the wafer in combination with the rotational movement of the wafer W and the swing of the supply arm 30.

[0080] It should be noted that when the wafer is rinsed, the nozzle of the first liquid spraying rod 51 is arranged towards the center of the wafer W, so that the ejected liquid falls on the center of the wafer, and the liquid ejected by the first liquid spraying rod covers the central area Zi of the wafer W.

[0081] The second liquid spraying rod 52 also assists in rinsing the wafer, and its landing point is obliquely above the center of the wafer W, and the sprayed rinsing liquid covers the outer region Ze of the wafer W.

[0082] The drying gas spraying rod 53 sprays drying gas towards the boundary line of the three-phase junction formed by the liquid, air and the wafer to strip the water film on the wafer surface and achieve drying of the wafer surface; wherein, the liquid film on the wafer surface forms a boundary line of the three-phase junction with air and the wafer W (referred to as the three-phase junction line, that is, solid-liquid-gas, that is, the three phases of the wafer, rinsing liquid, and air).

[0083] Furthermore, the wafer post-processing device 100 further includes a protective cover 60, which is sleeved on the outer peripheral side of the clamping and driving assembly 20 to control the landing point of the liquid centrifugally splashing from the wafer surface and prevent the liquid containing contaminants from directly splashing onto the inner side wall of the box body 10. It should be noted that the protective cover 60 is generally a closed annular structure. Figure 3 The lower part of the protective cover 60 is sectioned to clearly show the structure and positional relationship of the clamping and driving assembly 20 and the supply arm 30.

[0084] To solve the problems existing in the rinsing step in the wafer spin drying described in the background art, the present invention provides Figure 3 the spraying assembly 50 shown, so that a uniform liquid film is fully covered on the wafer surface.

[0085] During the wafer rinsing process, the supply arm 30 swings towards the center of the wafer W to be processed, as Figure 4 shown, so that the rinsing liquid sprayed by the first liquid spraying rod 51 lands at the center O of the wafer; at the same time, the second liquid spraying rod 52 sprays rinsing liquid towards the wafer, and its landing point P ( Figure 5 shown) is obliquely above the center of the wafer. Figure 5 In the embodiment shown, the liquid spraying landing point P of the second liquid spraying rod 52 is located above the left of the wafer center.

[0086] The rinsing liquid sprayed by the first liquid spraying rod 51 can fully cover the area of the wafer W near the center O, that is, the rinsing liquid covers the Figure 6 shown central region Zi; the central region Zi is circular. Taking a 12-inch wafer as an example, the radius of the central region Zi is about 50 mm.

[0087] The rinsing liquid sprayed by the second liquid spraying rod 52 can cover the area outside the vicinity of the wafer center, that is, the rinsing liquid covers the Figure 6 shown outer region Ze; the outer region Ze is annular. Taking a 12-inch wafer as an example, the rinsing liquid extends outward from a wafer radius of 25 mm to form an annular outer region Ze. Since the area covered by the second liquid spraying rod 52 is larger, the flow rate of the second liquid spraying rod 52 is greater than that of the first liquid spraying rod 51.

[0088] To ensure that the rinse liquid completely covers the surface of the wafer W to form a complete liquid film on the wafer surface, a circular overlapping area Zo is formed between the central area Zi and the outer area Ze, as Figure 6 shown.

[0089] In the present invention, the radial dimension of the overlapping area Zo is less than or equal to 1 / 3 of the radius of the wafer. Taking a 12-inch wafer as an example, the radial dimension of the overlapping area Zo is less than or equal to 50 mm.

[0090] In the present invention, the landing point of the rinse liquid sprayed by the first spray rod 51 is the center O of the wafer, while the landing point of the rinse liquid sprayed by the second spray rod 52 is the point P obliquely above the center O, that is, the liquid landing points of the two spray rods do not coincide, effectively avoiding sputtering caused by the collision of two liquid flows due to proximity.

[0091] The rinse liquid sprayed by the first spray rod 51 flows along the direction indicated by the small arrow 71 under the action of centrifugal force, as Figure 6 shown; since the distance between the landing point P and the center O of the wafer is relatively close, even if the rotation speed of the wafer is increased to 900 - 2500 rpm, the linear velocity at the landing point P is not high, and the rinse liquid sprayed by the second spray rod 52 flows along the direction of the large arrow 72, which conforms to the rotation direction of the wafer W; Figure 6 In the embodiment shown, the velocity difference between the fluid indicated by the small arrow 71 and the fluid indicated by the large arrow 72 is small. Therefore, even if the flow rate of the second spray rod 52 is large, the two will not cause sputtering due to the impact of the liquid flows.

[0092] In addition, the inner diameter of the nozzle of the second spray rod 52 is larger than that of the first spray rod 51, and the flow rate of the liquid sprayed by the second spray rod 52 is 200 - 1000 mL / min, and this flow rate will not cause the sprayed liquid flow to enter the turbulent sputtering state by itself.

[0093] In summary, by adopting the above technical solution, the present invention can spray and rinse the wafer W with the first spray rod 51 and the second spray rod 52 simultaneously in the rinsing step without causing liquid spraying sputtering, that is, a high-flow rinse agent and a high wafer rotation speed can be used simultaneously to improve the rinsing efficiency of the wafer.

[0094] Figure 7 FIG. is a schematic diagram of the supply arm 30 swinging to the central position of the rotating wafer W according to an embodiment of the present invention, which shows the structures and spatial position relationships of the first spray rod 51, the second spray rod 52, and the dry gas spray rod 53.

[0095] In the present invention, each spray rod of the spray assembly 50 is arranged along the length direction of the supply arm 30, and it is a single-landing-point spray rod, that is, the fluids sprayed by the first spray rod 51, the second spray rod 52, and the dry gas spray rod 53 land on the surface of the wafer W in the form of a single landing point to ensure the accuracy of the fluid landing point.

[0096] Figure 7 In the illustrated embodiment, the distance between the nozzle of the second liquid spraying rod 52 and the liquid falling surface is substantially the same as the distance between the nozzle of the first liquid spraying rod 51 and the liquid falling surface. Specifically, the distance between the nozzle of the second liquid spraying rod 52 and the wafer surface is 4 - 20 mm. It should be noted that the distance between the nozzle of the second liquid spraying rod 52 and the wafer surface should not be too large to prevent the liquid flow ejected from being interfered by gravity and affecting the accuracy of the liquid spraying landing point. Specifically, the liquids ejected by the first liquid spraying rod 51 and the second liquid spraying rod 52 move substantially in a straight line to avoid the liquid far from the nozzle forming a curved liquid flow, which will affect the control of the liquid spraying landing point.

[0097] It should be noted that there may be a difference of 0.1 - 5 mm between the distance between the nozzle of the second liquid spraying rod 52 and the liquid falling surface and the distance between the nozzle of the first liquid spraying rod 51 and the liquid falling surface.

[0098] Furthermore, the ends of the respective spraying rods of the spraying assembly 50 are bent towards the side of the wafer to be processed to form spraying ends, and the nozzles are located at the ends of the spraying ends to spray fluid towards the wafer, thereby realizing the cleaning and drying of the wafer surface.

[0099] Specifically, the end of the first liquid spraying rod 51 is bent towards the inside to form a spraying end, and the angle α between the spraying end and the rod body of the first liquid spraying rod 51 is 40 - 90°, as shown in Figure 8 (a) of. Here, the "inside" refers to the inside of the box body 10, that is, the position where the wafer to be processed is located. That is, except for the angle α being 90°, the angle between the rod body of the first liquid spraying rod 51 and the axis of the spraying end is an acute angle.

[0100] As in Figure 8 (a) of, there is a transition section 51a between the rod body of the first liquid spraying rod 51 and the spraying end. The setting of the transition section 51a is beneficial to adjusting the fluid velocity of the first liquid spraying rod 51.

[0101] Figure 8 In (b) of, the end of the second liquid spraying rod 52 is bent towards the inside, and the angle β between its spraying end and the rod body of the second liquid spraying rod 52 is 90 - 140°. That is, except for the angle β being 90°, the angle between the rod body of the second liquid spraying rod 52 and the axis of the spraying end is an obtuse angle.

[0102] Figure 8 In (c) of, the end of the dry gas spraying rod 53 is bent towards the inside, and the angle γ between its spraying end and the rod body of the dry gas spraying rod 53 is 70 - 110°. Preferably, the angle γ between the rod body of the dry gas spraying rod 53 and the axis of the spraying end formed by its bending is 90°.

[0103] It should be noted that controlling the distance that the spray tips of the first spray rod 51, the second spray rod 52 and the dry gas spray rod 53 extend toward the liquid falling surface can help ensure the accuracy of the fluid landing point; in addition, the distance between the spray tip and the liquid falling surface is also related to the height of the claw 22 of the clamping drive assembly 20, so as to avoid interference between the spray tip and the claw 22 and affect the normal operation of the wafer post-processing device.

[0104] Figure 9 3 is a schematic diagram of the injection assembly 50 on the supply arm 30 provided by an embodiment of the present invention relative to the wafer W. In this embodiment, the fluid sprayed by the first spray rod 51 conforms to the rotation direction of the wafer; the angle θ1 between the plane where the first spray rod 51 is located and the liquid falling surface is 45~85°, that is, the angle θ1 between the plane formed by the rod body of the first spray rod 51 and the central axis of the injection end and the liquid falling surface is; in this way, the sprayed liquid flow has a velocity component that conforms to the linear velocity direction of the solid surface of the wafer, so that the liquid flow falls on the wafer surface more smoothly, which is beneficial to stabilize the liquid film on the wafer surface and enhance the Marangoni drying effect.

[0105] At the same time, the nozzle of the first liquid spraying rod 51 is tilted toward the horizontal direction in accordance with the rotation direction of the wafer. Figure 7 As shown, this is beneficial for the spray liquid flow to follow the direction of the centrifugal force, which is beneficial for improving the drying effect of the wafer surface.

[0106] Figure 9 In the embodiment shown, the fluid sprayed by the second spray rod 52 and the fluid sprayed by the first spray rod 51 are interlaced to avoid the overlap of the landing points of the two and the splashing of the liquid flow. Specifically, the angle θ2 between the plane where the second spray rod 52 is located and the liquid landing surface is 45-85°, that is, the angle between the plane formed by the rod body of the second spray rod 52 and the central axis of the spray end and the liquid landing surface is θ2. That is, the nozzle of the second spray rod 52 is inclined upward ( Figure 7 As shown), it is beneficial to stagger the landing point position of the first liquid spray rod 51 and form a spray liquid flow that conforms to the liquid flow direction of the wafer surface to regulate the liquid spray landing points of the two and prevent the spray liquid flows from colliding with each other and causing sputtering.

[0107] It should be noted that the wafer post-processing device can also be designed to Figure 4 The structure is completely mirrored left and right. At this time, the landing point of the second spray rod 52 is located at the upper right of the center of the wafer. Figure 10 In this embodiment, the wafer W rotates counterclockwise under the drive of the clamping drive assembly 20 (not shown).

[0108] In addition, the present invention also provides a wafer post-processing method, which uses the above Figure 3 The wafer post-processing apparatus 100 is shown, and its flow chart is as follows: Figure 11 As shown, the wafer post-processing method includes the following steps:

[0109] S1, The wafer is placed on the clamping part of the clamping drive assembly 20, and the clamping part closes to vertically clamp the wafer W.

[0110] Specifically, an external manipulator vertically places the wafer on one side of the turntable 21 and is clamped by the claw 22, so that the clamping drive assembly 20 drives the wafer W to rotate around its axis.

[0111] S2, The supply arm 30 swings to the rinsing position, and the first liquid spraying rod 51 and the second liquid spraying rod 52 spray the rinsing liquid towards the rotating wafer.

[0112] Before the wafer post-processing device 100 starts to process the wafer surface, the supply arm 30 is usually in the horizontal position, that is, the spraying assembly 50 on the supply arm 30 is located outside the wafer to be processed; at this time, the supply arm 30 is in the standby position.

[0113] After the wafer post-processing device 100 starts the rinsing program, the supply arm 30 swings from the standby position to the rinsing position; wherein, the rinsing position means that the supply arm 30 swings towards the center of the wafer to be processed, and the liquid sprayed by the first liquid spraying rod 51 shoots towards the position corresponding to the center of the wafer.

[0114] When rinsing the wafer, the first liquid spraying rod 51 and the second liquid spraying rod 52 simultaneously spray the rinsing liquid towards the wafer surface, so as to quickly form a complete and uniform liquid film on the wafer surface to remove the contaminants remaining on the wafer surface. Wherein, the rinsing liquid is deionized water, or deionized water containing carbon dioxide. Specifically, the content of deionized water DIW in the rinsing liquid is not less than 90% whether calculated by mass or by molar ratio.

[0115] In the present invention, adding carbon dioxide gas to deionized water is beneficial to improving the conductivity of deionized water, reducing problems such as secondary pollution caused by static electricity on the wafer surface, and improving the post-processing effect of the wafer. It can be understood that during the wafer post-processing process, if static electricity is formed on the wafer surface, it is more likely to adsorb airborne particles, and rinsing the wafer surface with deionized water containing carbon dioxide will, to a certain extent, inhibit the occurrence of the above situation.

[0116] In step S2, the distance between the landing point P of the second liquid spraying rod 52 and the wafer center O is 25 - 50 mm, so that the sprayed rinsing liquid expands outwards from the landing point P under the combined action of centrifugal force and gravity to form a complete liquid film on the wafer surface.

[0117] During the wafer rinsing process, the spraying flow rate of the second liquid spraying rod 52 is greater than that of the first liquid spraying rod 51. Specifically, the spraying flow rate of the first liquid spraying rod 51 is 50 - 300 mL / min, while the spraying flow rate of the second liquid spraying rod 52 is 200 - 1000 mL / min to efficiently complete the rinsing of the wafer surface.

[0118] In step S2, the distance between the nozzle of the second spray rod and the wafer surface is 4 to 20 mm, so that the water flow moves basically in a straight line in the direction facing the nozzle, avoiding the formation of a curved liquid flow due to the distance from the nozzle, thereby improving the accuracy of the spray landing point.

[0119] S3, when the supply arm 30 swings from the rinsing position to the standby position, the dry gas spray rod 53 sprays dry gas, and the first liquid spray rod 51 sprays rinsing liquid;

[0120] After the wafer is rinsed, the supply arm 30 swings from the rinsing position to the standby position. During this process, the rinsing liquid from the first liquid spray rod 51 to the surface of the wafer W will spread due to the action of gravity and centrifugal force to form an asymmetric triangular liquid flow film that is approximately spiral. The liquid flow film starts from the landing point of the rinsing liquid on the wafer surface and gradually expands downward in the direction of the wafer rotation, and forms a boundary line of the three-phase intersection with the air and the wafer W; the dry gas spray rod 53 sprays dry gas toward the three-phase boundary line, and the surfactant in the dry gas quickly dissolves in the liquid flow film, and the liquid flow film at the three-phase contact line on the side of the wafer center O is The liquid will dissolve more surfactants, resulting in a decrease in the surface tension on the other side of the wafer center O, thereby forming a surface tension gradient from the rotation center O to the wafer edge in the liquid flow film. The direction of the Marangoni stress generated corresponding to the surface tension gradient points to the lower edge of the wafer. Under the combined action of the Marangoni stress, centrifugal force and gravity, the rinsing liquid flow sweeps toward the wafer edge as the supply arm 30 moves toward the lower edge of the wafer. The wafer surface area swept by the three-phase contact line on the other side of the wafer center O gradually moves toward the lower edge of the wafer until it leaves the surface of the wafer, thereby achieving the drying operation of the wafer.

[0121] In the present invention, the drying gas is formed into a mixture containing at least a surfactant such as iso-Propyl alcohol (IPA) that can reduce the surface tension of the rinsing liquid.

[0122] It should be noted that, during the Marangoni drying process, the second liquid spraying rod 52 does not need to supply the rinsing liquid, and the first liquid spraying rod 51 only needs to supply the rinsing liquid toward the three-phase intersection.

[0123] S4, the supply arm 30 remains in the standby position, and the wafer rotates at a high speed to dry the liquid remaining on the back of the wafer;

[0124] When the supply arm 30 swings to a horizontal state, the fluid sprayed by the dry gas spray rod 53 and the first spray rod 51 sweeps the entire area of the wafer surface to peel off the water film on the wafer surface and achieve drying of the wafer surface; then, the supply arm 30 remains in the standby position, and the wafer rotates at a speed of 900 to 2500 rpm to dry the residual liquid on the back of the wafer.

[0125] At S5, the clamping portion of the clamping drive assembly 20 opens to pick up the wafer after the post-treatment is completed.

[0126] In the present invention, during the wafer rinsing and drying process, the rotation speed of the wafer is 100 - 2500 rpm to ensure the rinsing effect and efficiency on the wafer surface and achieve rapid drying of the wafer surface.

[0127] Those of ordinary skill in the art can realize that the units and method steps of each example described in combination with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods for each specific application to implement the described functions, but such implementation should not be considered to exceed the scope of the embodiments of this application.

[0128] The above embodiments are only used to illustrate the embodiments of this application, rather than to limit the embodiments of this application. Those of ordinary skill in the relevant technical field can also make various changes and modifications without departing from the spirit and scope of the embodiments of this application. Therefore, all equivalent technical solutions also belong to the scope of the embodiments of this application, and the patent protection scope of the embodiments of this application should be defined by the claims.

Claims

1. A wafer post-processing device for vertically rotating and drying a wafer based on the Marangoni effect, characterized in that, Comprising: A box body; A clamping drive assembly, disposed on the back panel of the box body, for vertically clamping and driving the wafer to rotate; A supply arm, disposed in the box body, the supply arm swings vertically and supplies fluid to the wafer through a spraying assembly at its free end; The spraying assembly includes: A first liquid spraying rod, the landing point of which skims over the center of the wafer; A dry gas spraying rod, the landing point of which is located at the boundary line of the three-phase junction formed by the liquid, air and the wafer; A second liquid spraying rod, the landing point of which is located obliquely above the center of the wafer and the spraying direction conforms to the rotation direction of the wafer.

2. The wafer post-processing device according to claim 1, wherein The landing point of the second liquid spraying rod is located at the upper left or upper right of the center of the wafer, and the sprayed rinsing liquid covers the outer area of the wafer.

3. The wafer post-processing device according to claim 2, wherein The liquid sprayed by the first liquid spraying rod covers the central area of the wafer, and there is an overlapping part between it and the outer area; the overlapping part is an annular area concentric with the wafer.

4. The wafer post-processing device according to claim 3, wherein The radial dimension of the overlapping part is less than or equal to 1 / 3 of the radius of the wafer.

5. The wafer post-processing device according to claim 1, wherein The spraying rods of the spraying assembly are single-landing-point spraying rods, which are arranged along the length direction of the supply arm.

6. The wafer post-processing device according to claim 1, wherein, The inner diameter of the nozzle of the second liquid spraying rod is larger than the inner diameter of the nozzle of the first liquid spraying rod.

7. The wafer post-processing apparatus according to claim 1, wherein, The end of the first liquid spraying rod is bent inward to form a spraying end, and the angle between the spraying end and the rod body of the first liquid spraying rod is 40-90°.

8. The wafer post-processing apparatus according to claim 1, wherein The end of the second liquid spraying rod is bent inward to form a spraying end, and the angle between the spraying end and the rod body of the second liquid spraying rod is 90-140°.

9. The wafer post-processing device according to claim 1, wherein The end of the dry gas spraying rod is bent inward to form a spraying end, and the angle between the spraying end and the rod body of the dry gas spraying rod is 70-110°.

10. The wafer post-processing apparatus according to claim 1, wherein, The fluid sprayed by the first liquid spraying rod conforms to the rotation direction of the wafer, and the angle between the plane where the first liquid spraying rod is located and the liquid landing surface is 45-85°.

11. The wafer post-processing device according to claim 1, characterized in that, The fluid sprayed by the second liquid spraying rod intersects with the fluid sprayed by the first liquid spraying rod, and the angle between the plane where the second liquid spraying rod is located and the liquid landing surface is 45-85°.

12. A wafer post-treatment method, characterized in that, Using the wafer post-processing device according to any one of claims 1-11, comprising: S1, placing the wafer on the clamping part of the clamping drive assembly, and closing the clamping part to vertically clamp the wafer; S2, the supply arm swings to the rinsing position, and the first liquid spraying rod and the second liquid spraying rod spray rinsing liquid towards the rotating wafer; S3, during the process of the supply arm swinging from the rinsing position to the standby position, the dry gas spraying rod sprays dry gas, and the first liquid spraying rod sprays rinsing liquid; S4, the supply arm remains in the standby position, and the wafer rotates at a high speed to spin-dry the liquid remaining on the back of the wafer; S5, the clamping part of the clamping drive assembly is opened to take away the wafer after the post-processing is completed.

13. The wafer post-processing method according to claim 12, wherein, The spraying flow rate of the second liquid spraying rod is greater than the spraying flow rate of the first liquid spraying rod.

14. The wafer post-processing method according to claim 12, wherein The spraying flow rate of the first liquid spraying rod is 50-300 mL / min, and the spraying flow rate of the second liquid spraying rod is 200-1000 mL / min.

15. The post-wafer processing method according to claim 12, wherein In step S2, the rotation speed of the wafer is 900-2500 rpm; in step S3, the rotation speed of the wafer is 100-2000 rpm.

16. The wafer post-processing method according to claim 12, characterized in that, The distance between the landing point of the second liquid spraying rod and the center of the wafer is 25-50 mm.

17. The wafer post-processing method according to claim 12, wherein, In step S2, the distance between the nozzle of the second liquid spraying rod and the surface of the wafer is 4 - 20 mm.

18. The post-wafer processing method according to claim 12, wherein In step S3, the second liquid spraying rod stops supplying the rinsing liquid.

19. The wafer post-processing method according to claim 12, wherein When the supply arm is in the rinsing position, the nozzle of the first liquid spraying rod faces the center of the wafer to be processed; when the supply arm is in the standby position, the supply arm is in a horizontal position.

20. The wafer post-treatment method according to claim 12, characterized in that, The rinsing liquid is deionized water, or deionized water containing carbon dioxide.

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