Wafer post-processing device

Abstract

The present invention discloses a wafer post-processing device, which comprises: a driving mechanism, which vertically clamps the wafer and drives the wafer to rotate; a supply arm, which swings on the side of the wafer and supplies liquid to the wafer surface through the nozzle thereon; a retaining ring, which is arranged on the outer peripheral side of the driving mechanism; the retaining ring is equipped with a guide groove, which is arranged along the edge of the retaining ring contour, and the guide groove accumulates the fluid thrown out from the wafer and guides it to the lower part of the retaining ring.

Description

Technical Field

[0001] The invention belongs to the technical field of wafer drying, and in particular relates to a wafer post-processing device. Background Art

[0002] Wafer manufacturing is a key link in the development of the integrated circuit (IC) industry. As the feature size of integrated circuits continues to shrink, the requirements for wafer surface quality are getting higher and higher, so the control of defect size and quantity in the wafer manufacturing process is becoming more and more stringent. Contaminants are an important factor that causes the quality of the wafer surface to deteriorate and even cause defects. Therefore, cleaning technology is needed to desorb contaminants on the wafer surface to obtain an ultra-clean surface. In particular, liquid mark defects are easily encountered in the post-cleaning and drying of chemical mechanical polishing, which will lead to local changes in the oxide thickness and seriously affect the chip manufacturing qualification rate.

[0003] Patent CN111540702B discloses a vertical Marangoni wafer processing device, which adopts a semi-annular retaining ring structure with an arc-shaped inner wall. The retaining ring is hydrophilic and can catch the liquid thrown out from the edge of the wafer and guide the liquid toward the two ends of the retaining ring to prevent the liquid from being thrown onto the wall surfaces at higher positions such as the top wall of the chamber, thereby avoiding the fine droplets caused by the liquid colliding and sputtering at these positions to contaminate the front space and surface of the wafer.

[0004] When the liquid is thrown from the wafer to the inner arc surface of the semi-annular retaining ring, most of the liquid will flow along the inner wall of the retaining ring towards the two terminal directions of the semi-annular outer retaining ring; but there is also a small amount of liquid that will flow along the inner wall of the retaining ring away from the backplane, thereby accumulating into droplets at the edge of the retaining ring and randomly dripping onto the wafer surface, affecting the processing effect of the wafer surface. Summary of the invention

[0005] The present invention aims to solve one of the technical problems existing in the prior art to at least some extent.

[0006] To this end, an embodiment of the present invention provides a wafer post-processing device, which includes:

[0007] A driving mechanism that vertically clamps the wafer and drives the wafer to rotate;

[0008] a supply arm that swings at the side of the wafer and supplies liquid to the wafer surface via a nozzle thereon;

[0009] A retaining ring, which is arranged on the outer peripheral side of the driving mechanism;

[0010] The retaining ring is provided with a guide groove which is arranged along the edge of the retaining ring profile. The guide groove collects and guides the fluid thrown out from the wafer to the lower part of the retaining ring.

[0011] As a preferred embodiment, the guide groove is arranged on the inner side surface and / or the outer end surface of the edge of the retaining ring.

[0012] As a preferred embodiment, the number of the guide groove is at least one.

[0013] As a preferred embodiment, the guide groove is arranged perpendicular to the side surface of the edge of the retaining ring.

[0014] As a preferred embodiment, the cross-section of the guide groove is an elongated strip, and the ratio of its depth to width matches the capillary force of the adhesion fluid.

[0015] As a preferred embodiment, the ratio of the depth to the width of the guide groove is 0.1-50.

[0016] As a preferred embodiment, the retaining ring is an annular structure, and its edge is extended toward the center of the retaining ring; the inner side surface of the edge is provided with guide grooves, and the guide grooves are arranged at intervals along the radial direction of the retaining ring.

[0017] As a preferred embodiment, the width of the guide groove close to the center of the retaining ring is smaller than the width of the guide groove far from the center of the retaining ring.

[0018] As a preferred embodiment, the guide groove is arranged to be inclined relative to the side surface of the edge of the retaining ring.

[0019] As a preferred embodiment, the retaining ring is detachably fixed to a back plate of the wafer post-processing device to cover the entire driving mechanism.

[0020] The beneficial effects of the present invention include: the guide groove configured in the retaining ring accumulates and guides the fluid thrown out from the wafer to the lower part of the retaining ring, effectively avoiding the accumulation and dripping of droplets on the top of the retaining ring, and effectively ensuring the effect of wafer surface treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The advantages of the present invention will become clearer and easier to understand through the detailed description made in conjunction with the following drawings, which are only schematic and do not limit the scope of protection of the present invention, wherein:

[0022] Figure 1 It is a structural schematic diagram of the wafer post-processing device of the present invention;

[0023] Figure 2 is a schematic diagram of an embodiment of the guide groove of the present invention;

[0024] Figure 3 is a schematic diagram of another embodiment of the guide groove of the present invention;

[0025] Figure 4 It is a schematic diagram of another embodiment of the guide groove of the present invention. DETAILED DESCRIPTION

[0026] The technical scheme of the present invention is described in detail below in conjunction with specific embodiments and their accompanying drawings. The embodiments recorded herein are specific embodiments of the present invention, which are used to illustrate the concept of the present invention; these descriptions are explanatory and exemplary and should not be construed as limitations on the embodiments of the present invention and the scope of protection of the present invention. In addition to the embodiments recorded herein, those skilled in the art can also adopt other obvious technical solutions based on the contents disclosed in the claims of this application and its specification, including technical solutions that adopt any obvious replacements and modifications to the embodiments recorded herein.

[0027] The drawings of this specification are schematic diagrams, which assist in explaining the concept of the present invention and schematically show the shapes of various parts and their mutual relationships. It should be understood that in order to clearly show the structures of various components of the embodiments of the present invention, the drawings are not drawn according to the same scale, and the same reference numerals are used to represent the same parts in the drawings.

[0028] In the present invention, "Chemical Mechanical Polishing (CMP)" is also called "Chemical Mechanical Planarization (CMP)", and the wafer (Wafer, W) is also called substrate (Substrate), and their meanings and actual functions are equivalent.

[0029] Figure 1 1 is a schematic diagram of the structure of a wafer post-processing device 100 according to the present invention, which includes a driving mechanism 10 and a supply arm 20, both of which are arranged in a box. Among them, the driving mechanism 10 is a disc-shaped structure, and its outer edge is provided with a claw to reliably clamp the wafer; the rear side of the driving mechanism 10 is provided with a driving motor to drive the wafer to rotate in a vertical plane. Driven by the motor assembly, the supply arm 20 swings in a vertical plane parallel to the plane where the wafer W is located. The supply arm 20 is provided with a nozzle at its free end, so that liquid can be supplied to the global surface of the rotating wafer W through the nozzle moving with the supply arm 20.

[0030] The wafer post-processing device 100 also includes a retaining ring 30, which is arranged on the outer peripheral side of the driving mechanism 10 to prevent liquid thrown out by centrifugal force on the wafer surface from falling onto the top wall of the box chamber, thereby preventing small droplets caused by liquid impact and sputtering at these positions from contaminating the front space and surface of the wafer, and preventing droplets formed by liquid accumulation on the top wall of the chamber from dripping downward and contaminating the wafer.

[0031] Since some liquid droplets will also accumulate on the upper side of the retaining ring 30, these liquid droplets will also affect the post-processing of the wafer. In order to solve the above technical problems, the retaining ring 30 of the present invention is equipped with a guide groove 30a, such as Figure 2As shown, it is arranged along the edge of the contour of the retaining ring 30, and the guide groove 30a can guide the liquid thrown out of the wafer to the lower part of the retaining ring 30. Specifically, the droplets accumulated on the top of the inner side wall of the retaining ring 30 can flow toward the lower part of the retaining ring 30 under the guidance of the guide structure to prevent the droplets from dripping onto the wafer surface under the action of gravity.

[0032] Figure 2 In the illustrated embodiment, there are two guide grooves 30a, which are spaced apart along the radial direction of the retaining ring 30. Liquid droplets on the liquid receiving surface 31 of the inner wall of the retaining ring 30 slide toward the edge of the retaining ring and slide into the interior of the guide grooves.

[0033] Further, the cross section of the guide groove 30a is a long strip, and the ratio of its depth to width matches the capillary force of the attached liquid. Specifically, the width of the guide groove 30a is set so that it can provide a suitable capillary force to accumulate the liquid in the guide groove 30a and reliably limit the liquid to flow in the guide groove 30a. It is understandable that the capillary force of the guide groove 30a should not be too strong, as too strong capillary force will make it difficult for the liquid to be discharged from the end of the guide groove by gravity and siphon action.

[0034] The width of the guide groove 30a is in the range of 0.02 mm to 8 mm, and the width of the guide groove can be comprehensively determined according to the working conditions of the wafer post-processing device, such as the water flow rate of cleaning and drying.

[0035] To ensure that the guide groove 30a has sufficient water storage capacity without affecting its capillary force, the ratio of the depth to the width of the guide groove 30a is 0.1 to 50. Preferably, the ratio of the depth to the width of the guide groove 30a is 0.5 to 10.

[0036] During wafer post-processing, the droplets gradually gathered on the inner top of the retaining ring 30 will move along the liquid receiving surface 31 toward the edge of the retaining ring 30 away from the chamber back plate under the action of gravity; when the droplets touch the opening position of the guide groove 30a, they will be quickly pulled into the guide groove 30a due to the capillary action of the narrow slit structure of the guide groove.

[0037] If the amount of liquid at the position where the liquid is obtained in the guide groove 30a continues to increase, the increased liquid will remain in the guide groove 30a due to capillary action and will be transported along the guide groove 30a to both sides or one side of the position; when the adhesion force between the liquid and the inner wall of the guide groove 30a is not sufficient to offset the gravity of the liquid, the liquid will flow downward along the guide groove 30a to the end of the guide groove.

[0038] When the liquid in the end groove of the guide groove 30a accumulates to a critical discharge height in the vertical direction, the additional liquid at the end will flow out from the end of the guide groove 30a in an amount equal to the newly added liquid because the capillary force of the guide groove cannot withstand the gravity. In this way, a cycle of accumulated liquid flow and diversion and drainage in the guide groove 30a is formed, thereby continuously and smoothly draining away the excess liquid on the top without dripping and contaminating the wafer.

[0039] Figure 2 In the embodiment, two guide grooves 30a are arranged on the edge of the retaining ring 30, which are perpendicular to the side of the edge, namely, the first guide groove 30a-1 and the second guide groove 30a-2. The depth and width of the guide groove 30a are in the millimeter level to form a groove structure with a large cross-sectional area, thereby ensuring its guide capacity and realizing fast and efficient guide.

[0040] When the liquid flow rate that needs to be diverted locally exceeds the accumulation capacity of the first diversion groove 30a-1, the overflowed liquid will be accumulated and diverted by the second diversion groove 30a-2. It can be understood that the second diversion groove 30a-2 near the lower end face of the edge of the retaining ring 30 is equivalent to the second line of defense, which effectively enhances the reliability of the anti-drip effect of the retaining ring 30.

[0041] Furthermore, the geometrical dimension of the guide groove 30a is at the millimeter level, which is beneficial to ensure the structural strength; at the same time, the millimeter-level groove structure is convenient for selection and processing to control the processing cost.

[0042] It is understandable that the guide groove of the retaining ring 30 can also be set to one, three, or more, as long as the guide capacity of the retaining ring 30 matches the process technology of the wafer post-processing device.

[0043] As an embodiment of the present invention, the guide groove 30a is provided on the inner side surface 33 and the outer end surface 34 of the edge of the retaining ring 30. Figure 3 As shown. The retaining ring 30 has multiple guide grooves, and when viewed from the longitudinal section, the width and depth of the guide grooves 30a may also be different. The guide grooves 30a with smaller widths have stronger capillary suction, but the decrease in cross-sectional area will reduce its flow-conducting capacity. Configuring a larger number of guide grooves 30a can supplement the flow-conducting capacity. Liquid that one guide groove 30a does not have time to accumulate and guide will be accumulated and guided by the adjacent guide grooves 30a. Since the width and depth of the guide grooves 30a used in this embodiment are relatively small, there is no need to significantly thicken the outer edge of the retaining ring 30 away from the back plate of the box body due to the provision of the guide grooves 30a, so as to avoid occupying other working space inside the box body chamber.

[0044] Figure 43 is a schematic diagram of another embodiment of the guide groove of the present invention. The structure can guide a relatively small liquid flow rate and is suitable for scenes with a small liquid flow rate. The guide groove 30a is located at the lower end surface 34 of the edge of the retaining ring 30. Such a configuration is conducive to designing a steeper cross-section line of the liquid contact surface 31 of the retaining ring 30, so that the angle between the direction of the wafer ejecting the liquid and the liquid contact surface 31 is smaller, so as to enhance the anti-sputtering capability.

[0045] As Figure 2 As a variation of the embodiment, the guide groove 30a may also be inclined relative to the side of the edge of the retaining ring 30, so as to ensure the guiding effect of the guide groove 30a and prevent the liquid droplets on the top of the inner wall of the retaining ring 30 from dripping and affecting the post-processing effect of the wafer.

[0046] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0047] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A wafer post-processing device, characterized in that: include: A driving mechanism that vertically clamps the wafer and drives the wafer to rotate; a supply arm that swings at the side of the wafer and supplies liquid to the wafer surface via a nozzle thereon; A retaining ring, which is arranged on the outer peripheral side of the driving mechanism; The retaining ring is provided with a guide groove, which is arranged along the edge of the retaining ring profile, and the guide groove accumulates and guides the fluid thrown out from the wafer to the lower part of the retaining ring; The retaining ring is an annular structure, and its edge is extended toward the center of the retaining ring; the guide groove is arranged on the inner side and outer end surface of the retaining ring edge, and the inner side of the edge is provided with a plurality of guide grooves, which are arranged at intervals along the radial direction of the retaining ring; the width of the guide groove close to the center of the retaining ring is smaller than the width of the guide groove far from the center of the retaining ring; The width and depth of the guide grooves on the inner side surface and the outer end surface are different.

2. The wafer post-processing device according to claim 1, characterized in that: The cross section of the guide groove is a long strip, and the ratio of its depth to width matches the capillary force of the affinity fluid.

3. The wafer post-processing device according to claim 2, characterized in that: The ratio of the depth to the width of the guide groove is 0.1-50.

4. The wafer post-processing device according to claim 1, characterized in that: The retaining ring is detachably fixed to the back plate of the wafer post-processing device to cover the driving mechanism as a whole.

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