Wafer horizontal caching device

Abstract

The invention discloses a wafer horizontal caching device, the wafer horizontal caching device comprises a support frame and a detection assembly, the support frame is used for horizontally supporting a wafer, the detection assembly is arranged on a fixed frame, and the fixed frame is located at two sides of the horizontally supported wafer; the detection assembly comprises a signal receiving and transmitting part and a reflection part arranged in a matched mode, the detection assembly is installed on the fixing frame, optical signals output by the signal receiving and transmitting part are emitted towards the reflection part, and the reflection part reflects the optical signals to the signal receiving and transmitting part; the detection assembly judges whether the wafer is placed on the support frame or not according to the optical signal received by the signal receiving and transmitting part; the detection assembly further comprises a shading plate which is arranged on the side portion of the reflection portion in a covering mode. And a non-mirror surface structure is configured on the surface of the light shielding plate so as to prevent light rays emitted by the signal receiving and transmitting part from being reflected to interfere with detection.

Description

[0001] This divisional application is a divisional application based on the original patent application with application number 2021115333017 and application date December 15, 2021.

[0002] The original application enjoyed the priority of December 22, 2020, and this divisional application continues to retain that priority. Technical Field

[0003] The present invention belongs to the field of semiconductor technology, and in particular relates to a wafer horizontal buffer device. Background Art

[0004] Figure 1 This is a schematic diagram of a conventional wafer horizontal buffer device, which is configured with stacked support racks. In order to control the movement of the transport robot, it is necessary to determine in advance whether a wafer is placed on the support rack.

[0005] Currently, the presence of wafers is detected using an optical sensor. The sensor emits an optical signal toward the wafer, which is then matched with a reflector. The reflector receives the optical signal and transmits it back to the sensor. If a wafer is on the support, the optical signal is blocked by the wafer, and the reflector cannot receive the optical signal, and the corresponding optical sensor cannot receive the reflected optical signal. If the support is empty, the optical signal is directed toward the reflector and transmitted back to the sensor.

[0006] During wafer processing, optical signals will be emitted when the water film on the wafer is irradiated. Figure 1 As shown in FIG, the optical signal emitted by the water film may be received by the reflector of the adjacent support frame, which may interfere with the state determination of the adjacent support frame and even cause misjudgment and affect the normal operation of the transfer robot.

[0007] Furthermore, due to the low precision of the reflective surface machining, it is prone to roughness. This can cause diffuse reflection, which in turn affects the reception of optical signals and interferes with the accuracy of wafer presence detection. Furthermore, the method of determining wafer presence based on optical signal reception is somewhat limited, which carries the risk of detection errors and cannot ensure measurement accuracy through mutual verification. Summary of the Invention

[0008] The present invention aims to solve one of the technical problems existing in the prior art to at least a certain extent.

[0009] To this end, an embodiment of the present invention provides a wafer horizontal buffer device, which includes a support frame and a detection component, wherein the support frame is used to horizontally support the wafer, and the detection component is arranged on a fixed frame, and the fixed frame is located on both sides of the horizontally supported wafer; the detection component includes a signal transceiver and a matching reflector, which is installed on the fixed frame, and the optical signal output by the signal transceiver is emitted toward the reflector, and the reflector reflects the optical signal to the signal transceiver; the detection component determines whether the support frame has a wafer placed on it based on the optical signal received by the signal transceiver; the detection component also includes a light shielding plate, which is covered on the side of the reflector; the detection component also includes a light shielding plate covered on the side of the reflector, and / or, also includes a light intensity sensor for detecting the intensity of the optical signal.

[0010] As a preferred embodiment, the surface of the light shielding plate is configured with a non-mirror structure to prevent the light emitted by the signal transceiver from being reflected and interfering with the detection accuracy.

[0011] As a preferred embodiment, the non-mirror structure includes a plurality of columnar structures extending outward from the side surfaces of the light shielding plate, and the columnar structures are evenly arranged on the surface of the light shielding plate.

[0012] As a preferred embodiment, the columnar structure is a cylinder, the radius of the cylinder is 0.2-0.5 mm, and the height thereof is less than or equal to 2 mm.

[0013] As a preferred embodiment, the light intensity sensor is arranged on the reflecting part and is opposite to the signal transceiver part to detect the intensity of the optical signal emitted by the signal transceiver part.

[0014] As a preferred embodiment, the light intensity sensor is arranged between the reflecting part and the light shielding plate, the light shielding plate is provided with a light-transmitting hole, and the optical signal of the signal transceiver is incident on the light intensity sensor via the light-transmitting hole.

[0015] As a preferred embodiment, there is at least one support frame, which is evenly spaced along the vertical direction of the fixing frame; the signal transceiver parts and the reflector parts of the detection components configured on adjacent support frames are staggered.

[0016] The beneficial effects of the present invention include:

[0017] In the present invention, a light shielding plate with a light-transmitting hole is provided on the outer side of the reflecting part to prevent the water film on the surface of the wafer from interfering with the detection results; furthermore, a non-mirror structure is arranged on the outer side of the light shielding plate to absorb the light emitted by the signal transceiver part to prevent its emission from interfering with the detection, thereby improving the accuracy of the detection; in addition, the signal transceiver part and the reflecting part of the detection component arranged on adjacent support frames are staggered, which is also conducive to reducing detection interference, improving detection accuracy, and ensuring the smoothness of wafer caching and transmission. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] 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 exemplary and do not limit the scope of protection of the present invention, wherein:

[0019] Figure 1 It is a schematic diagram of a wafer level buffer device in the prior art;

[0020] Figure 2 It is a structural schematic diagram of a wafer horizontal buffer device according to the present invention;

[0021] Figure 3 is a schematic diagram of the connection between the reflective portion and the light shielding plate of the present invention;

[0022] Figure 4 Schematic diagram of the structure of the sunshade of the present invention;

[0023] Figure 5 yes Figure 4 a front view of the corresponding sunshade;

[0024] Figure 6 is a schematic diagram of another embodiment of the reflective portion of the present invention;

[0025] Figure 7 is a schematic diagram of another embodiment of the sunshade of the present invention;

[0026] Figure 8 is a schematic diagram of a detection assembly equipped with a light intensity sensor according to the present invention;

[0027] Figure 9 It is a schematic diagram of another embodiment of a wafer horizontal buffer device described in the present invention. DETAILED DESCRIPTION

[0028] The technical solutions of the present invention are described in detail below in conjunction with specific embodiments and the accompanying drawings. The embodiments described herein are specific embodiments of the present invention and are used to illustrate the concept of the present invention; these descriptions are explanatory and exemplary and should not be understood as limiting the embodiments of the present invention and the scope of protection of the present invention. In addition to the embodiments described 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 described herein.

[0029] The drawings in this specification are schematic diagrams that assist in illustrating the concepts of the present invention and schematically illustrate the shapes of the various components and their interrelationships. It should be understood that in order to clearly illustrate the structures of the various components of the embodiments of the present invention, the drawings are not drawn to the same scale, and the same reference numerals are used to represent the same parts in the drawings.

[0030] In the present invention, "Chemical Mechanical Polishing (CMP)" is also called "Chemical Mechanical Planarization (CMP)", and the wafer is also called substrate, and their meanings and actual functions are equivalent.

[0031] A schematic structural diagram of a wafer level buffer device according to the present invention is shown as follows: Figure 2 As shown, the wafer horizontal buffering device 100 includes a support frame 10 for horizontally supporting wafers and a detection assembly 20. The support frame 10 is used to horizontally support wafers, and the detection assembly 20 is disposed on the outer periphery of the support frame 10. Specifically, the detection assembly 20 is mounted on a fixing frame 30, which is a component for mounting the detection assembly 20; the fixing frames 30 are usually arranged in pairs on both sides of the support frame 10.

[0032] Figure 2 In the illustrated embodiment, two support frames 10 are stacked vertically, with the spacing between adjacent support frames 10 matching the travel space of the transport robot. The top surfaces of the support frames 10 are provided with a plurality of raised structures, which follow the outer contours of the wafers to provide horizontal support for the wafers.

[0033] Furthermore, the detection component 20 includes a signal transceiver 21 and a matching reflector 22. The optical signal output by the signal transceiver 21 is transmitted toward the reflector 22, and the reflector 22 reflects the optical signal to the signal transceiver 21. The detection component 20 determines whether a wafer is placed on the support frame 10 based on the optical signal received by the signal transceiver 21. Specifically, if the signal transceiver 21 receives the optical signal emitted from the reflector 22, then the support frame 10 does not place a wafer; if the signal transceiver 21 does not receive the optical signal emitted from the reflector 22, then the support frame 10 does place a wafer. This is because the optical signal is irradiated on the wafer of the support frame 10, causing reflection, changing the transmission route and failing to irradiate the reflector 22 normally.

[0034] Figure 2In the figure, the optical signal emitted by the signal transceiver 21 is represented by a thin solid line. The signal transceiver 21 transmits the optical signal at an angle less than 10° toward the plane of the support frame 10, so that the emitted light passes through the plane of the wafer. As one aspect of this embodiment, the optical signal is tilted at a 5° angle to the plane of the support frame 10 to control the range of the optical signal and reduce interference with other components of the semiconductor device.

[0035] Furthermore, the detection assembly 20 further includes a light shielding plate 23, which is provided on the side of the reflecting portion 22 facing the support frame 10, as shown in FIG. Figure 3 As shown, the provision of the light shield 23 can prevent interference with the detection results from the inspection assembly 20 configured on the adjacent support frame 10, thereby ensuring the accuracy of the detection. Specifically, due to the presence of a water film on the surface of the wafer, the optical signal irradiated by the water film may be scattered. The scattered light illuminates the reflective portion 22 configured on the adjacent support frame 10 and is reflected back to the corresponding signal transceiver 21, which may cause a misjudgment. In other words, if a wafer is originally placed on the adjacent support frame 10 and the matching inspection assembly 20 detects the reflected optical signal, it is determined that the support frame 10 does not have a wafer placed on it.

[0036] Figure 1 The detection assembly 20 shown is equipped with a light shielding plate 23 , which can block the interference of wafers on adjacent support frames 10 on the detection results, thereby improving the accuracy of the detection assembly 20 .

[0037] Furthermore, the light shielding plate 23 is provided with a light-transmitting hole 23a. The optical signal emitted by the signal transceiver 21 is incident on the reflective portion 22 through the light-transmitting hole 23a, and then transmitted from the reflective portion 22 through the light-transmitting hole 23a to the signal transceiver 21. In other words, the light shielding plate 23 can filter out other interfering signals and improve the accuracy of wafer detection.

[0038] Figure 4 The diagram is a schematic diagram of the structure of the light shielding plate according to the present invention. Light shielding plate 23 comprises a top plate 23b and bosses 23c. Bosses 23c are positioned at both ends of top plate 23b to form a U-shaped structure. The dimensions of top plate 23b match the shape of reflective portion 22. As one aspect of this embodiment, bosses 23c have a height of 2mm-5mm to control the incidence and reflection of optical signals from signal transceiver 21 through light-transmitting aperture 23a.

[0039] As one aspect of this embodiment, the light-transmitting hole 23a is a through-hole eccentrically disposed on the top plate 23b of the light-shielding plate 23. The eccentric arrangement of the light-transmitting hole 23a primarily aims to illuminate the interior of the light-transmitting hole 23a with the optical signal emitted by the signal transceiver 21. The optical signal is then reflected from the interior of the light-transmitting hole 23a back to the signal transceiver 21. This allows the reflection of the optical signal to be controlled within a controllable range, thereby improving detection accuracy.

[0040] Figure 2 The wafer horizontal buffer device 100 shown is equipped with a light shielding plate 23, which reduces the false alarm rate of wafer detection from the original 1% to 0.02‰, effectively ensuring the smoothness of wafer buffering and turnover.

[0041] Figure 5 In the embodiment, the light-transmitting hole 23a is a waist-shaped hole, and the center of the waist-shaped hole is located below the horizontal center line of the light shielding plate 23. As another aspect of this embodiment, the distance between the center of the waist-shaped hole and the horizontal center line of the light shielding plate 23 is 1mm-3mm. Figure 2 In the illustrated embodiment, the distance between the center of the light-transmitting hole 23a and the horizontal centerline of the light shield 23 is 2 mm. This arrangement can reduce the impact of external interference signals on the detection results and improve the accuracy of wafer detection. In the present invention, the size and location of the light-transmitting hole 23a are related to the angle of the optical signal emitted by the signal transceiver 21, the spacing between adjacent support frames 10, and the surface reflectivity characteristics of the wafer. Therefore, it is necessary to consider these factors comprehensively when setting the light-transmitting hole 23a.

[0042] In order to reduce the use of metal materials and avoid the influence of metal ions on wafer manufacturing, the light shielding plate 23 is made of non-metallic materials, and the top plate 23b is coated with an anti-reflection coating.

[0043] As one aspect of this embodiment, the light shielding plate 23 is made of polytetrafluoroethylene, and the refractive index of the anti-reflection coating is 1-1.5. It is understood that in order to prevent the optical signal directed to the surface of the light shielding plate 23 from being reflected and interfering with wafer detection, the refractive index of the anti-reflection coating can be between that of air and glass.

[0044] As another aspect of this embodiment, the thickness of the anti-reflection coating is 0.001 mm to 0.1 mm. Preferably, the thickness of the anti-reflection coating is 0.05 mm. The anti-reflection coating is a thin dielectric coating applied to the surface of the light shielding plate 23 to reduce the surface's reflectivity to light of a certain wavelength range.

[0045] Specifically, the anti-reflective coating is a substance that is spin-coated at the interface between the photoresist and the Si substrate to absorb the light reflected by the photolithography. It mainly includes bottom anti-reflective coating, top anti-reflective coating, developable bottom anti-reflective coating, spin-coated Si-containing anti-reflective coating, carbon coating, etc. Among them, the bottom anti-reflective coating is a coating located between the Si substrate and the photoresist. The bottom anti-reflective coating is mainly composed of a cross-linkable resin, a thermal acid generator, a surfactant and a solvent.

[0046] As a variation of this embodiment, in order to control the optical signal to be emitted within a limited range to reduce the influence of light reflection on the wafer detection of the adjacent support frame 10, a light absorbing layer 22a can be partially coated on the side of the reflective portion 22, such as Figure 6 As shown. The light absorbing layer 22a is coated on the outside of the reflective portion 22, which can absorb external interference signals and prevent optical signal reflection from interfering with wafer detection. That is, only the area not coated with the light absorbing layer 22a is controlled to reflect to improve detection accuracy.

[0047] Figure 6 In the illustrated embodiment, the uncoated area of the light-absorbing layer 22a is a waist-shaped region, which is eccentrically disposed on a side surface of the reflective portion 22, where the side surface is the plane facing the support frame 10. In some embodiments, the waist-shaped structure is eccentrically disposed on a side surface of the reflective portion 22. The distance between the center of the waist-shaped structure and the horizontal centerline of the reflective portion 22 is 2 mm. Figure 6 The waist-shaped area without light-absorbing material is represented by a solid line. The waist-shaped area is not a through hole. Figure 5 The light-transmitting aperture 23a shown is essentially different. Figure 5 The light-transmitting hole 23 a is a through hole, and the horizontal projection of the light-transmitting hole 23 a corresponds to the waist-shaped area of the reflecting portion 22 .

[0048] As one aspect of this embodiment, the light-absorbing layer 22a can be configured to match the wavelength of the optical signal emitted by the signal transceiver 21 to prevent reflection from the light-absorbing layer 22a and interference with wafer inspection. Preferably, the thickness of the light-absorbing layer 22a is 0.01-0.1 mm. The provision of the light-absorbing layer 22a can reduce the number of light shielding plates 23, reduce the number of components in the wafer-level buffering device, and control the manufacturing and processing costs of the wafer-level buffering device.

[0049] It is understandable that in order to strictly control the impact of optical signal reflection on wafer detection, the reflective portion 22 configured with the light absorbing layer 22a can be used in combination with the light shielding plate 23 to avoid misjudgment of wafer detection and prevent mutual interference of the detection components 20.

[0050] As another embodiment of the present invention, the surface of the light shielding plate 23 is configured with a non-mirror structure 23d to prevent the light emitted by the signal transceiver 21 from being reflected and interfering with the detection, thereby improving the accuracy of wafer in-situ detection.

[0051] As one aspect of this embodiment, the non-mirror structure 23d includes a plurality of columnar structures extending outward from the side of the light shielding plate, and the columnar structures are evenly arranged on the surface of the light shielding plate. In some embodiments, the non-mirror structure 23d is a cylinder, such as Figure 7 As shown, it is evenly arranged on the surface of the light shielding plate 23; the radius of the cylinder is 0.2-0.5mm, and its height is less than or equal to 2mm. Such arrangement of the light shielding plate 23 can effectively increase the surface roughness of the light shielding plate 23 and avoid light reflection.

[0052] It is understandable that the non-mirror structure 23d can also adopt other structural forms, such as a rectangular columnar structure, or the surface of the light shielding plate 23 can be sandblasted to increase the surface roughness of the light shielding plate 23 to prevent the light shielding plate 23 from emitting light and affecting the in-situ detection of the wafer.

[0053] As another embodiment of the present invention, the wafer level buffer device further includes a light intensity sensor 24, such as Figure 8 As shown, the light intensity sensor 24 is used to detect the intensity of the optical signal.

[0054] Specifically, the light intensity sensor 24 is arranged on the reflecting part 22 and is opposite to the signal transceiver 21 to detect the intensity of the optical signal emitted by the signal transceiver 21. That is, the light intensity sensor 24 is arranged between the reflecting part 22 and the light shielding plate 23, and the light shielding plate 23 is configured with Figure 4 The light-transmitting hole 23 a is shown, and the optical signal of the signal transceiver 21 is incident on the light intensity sensor 24 through the light-transmitting hole 23 a.

[0055] Figure 8 In the illustrated embodiment, the light intensity sensor 24 is capable of detecting the intensity of the optical signal so as to detect whether there is liquid on the wafer surface that absorbs the optical signal, thereby achieving accurate detection of the wafer being in place.

[0056] In some embodiments, a light intensity sensor 24 may be optionally configured to work with the detection assembly 20 equipped with a light shielding plate 23 to achieve in-situ detection of the wafer.

[0057] Figure 9It is a schematic diagram of another embodiment of a wafer horizontal buffer device 100 described in the present invention. In this embodiment, there are three support frames 10, which are evenly spaced in the vertical direction; the signal transceiver parts 21 and the reflective parts 22 of the detection components 20 configured on adjacent support frames 10 are staggered. Specifically, the signal transceiver 21 configured on one support frame 10 is located on the left, and the matching reflective part 22 is located on the right; the reflective part 22 configured on the adjacent support frames 10 is located on the left, and the matching signal transceiver 21 is located on the right. The staggered arrangement of the signal transceiver parts 21 configured on adjacent support frames 10 avoids mutual interference of light reflections to a certain extent, thereby improving the accuracy of wafer detection.

[0058] Furthermore, the wafer-level buffering device disclosed in the present invention can be applied to a chemical mechanical polishing system. It is understood that the wafer-level buffering device described in the present invention can also be applied to other semiconductor equipment, such as wafer thinning equipment and wafer packaging equipment, to address the problem of uneven production cycles.

[0059] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, illustrative uses of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0060] While 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 invention, and that the scope of the invention is defined by the claims and their equivalents.

Claims

1. A wafer level buffer device, characterized in that: The invention comprises a support frame and a detection component, wherein the support frame is used to horizontally support the wafer, and the detection component is arranged on a fixing frame, and the fixing frame is located on both sides of the horizontally supported wafer; the detection component comprises a signal transceiver and a matching reflector, which is installed on the fixing frame, and the optical signal output by the signal transceiver is transmitted toward the reflector, and the reflector reflects the optical signal to the signal transceiver; the detection component determines whether the support frame has placed the wafer based on the optical signal received by the signal transceiver; the detection component also includes a light shielding plate covering the side of the reflector, and also includes a light intensity sensor for detecting the intensity of the optical signal; The signal transceiver transmits an optical signal tilted toward the plane where the support frame is located, and its tilt angle is less than 10°, so that the emitted light passes through the plane where the wafer is located; the light shield is configured with an eccentric light-transmitting hole, and the projection of the light-transmitting hole toward the reflective portion forms a waist-shaped area; the outer side of the waist-shaped area of the reflective portion is coated with a light-absorbing layer to absorb external interference signals and prevent the optical signal from being reflected and interfering with wafer detection; the light-absorbing layer is matched with the wavelength of the optical signal emitted by the signal transceiver to prevent reflection from the light-absorbing layer and interfering with wafer detection; There is at least one supporting frame, which is evenly spaced along the vertical direction of the fixing frame; the signal transceiver parts and the reflector parts of the detection components arranged on adjacent supporting frames are staggered.

2. The wafer level buffer device according to claim 1, wherein: The thickness of the light absorbing layer is 0.01-0.1 mm.

3. The wafer level buffer device according to claim 1, wherein: The distance between the center of the waist-shaped area and the horizontal midline of the reflecting portion is 2 mm.

4. The wafer level buffer device according to claim 1, wherein: The horizontal projection of the light-transmitting hole corresponds to the waist-shaped area of the reflecting part.

5. The wafer level buffer device according to claim 1, wherein: The surface of the shading plate is sandblasted and roughened to increase the surface roughness of the shading plate.

6. The wafer level buffer device according to claim 1, wherein: There are three support frames, which are evenly spaced in the vertical direction.

7. The wafer level buffer device according to claim 1, wherein: The surface of the light shielding plate is configured with a non-mirror structure to prevent the light emitted by the signal transceiver from being reflected and interfering with the detection accuracy; the non-mirror structure includes a plurality of columnar structures extending outward from the side of the light shielding plate, and the columnar structures are evenly arranged on the surface of the light shielding plate.

8. The wafer level buffer device according to claim 1, wherein: The light intensity sensor is disposed on the reflecting portion and is opposite to the signal transceiver portion to detect the intensity of the optical signal emitted by the signal transceiver portion.

9. The wafer level buffer device according to claim 8, wherein: The light intensity sensor is arranged between the reflecting part and the light shielding plate. The light shielding plate is provided with a light-transmitting hole. The optical signal of the signal transceiver is incident on the light intensity sensor via the light-transmitting hole.

10. A chemical mechanical polishing system, characterized in that: A wafer level buffer device comprising the wafer level buffer device according to any one of claims 1 to 9.

Images