A wafer-level caching device

Abstract

The present invention discloses a wafer horizontal caching device. The wafer horizontal caching device includes a support frame and a detection component. The support frame is used for horizontally supporting wafers. The detection component is arranged on a fixed frame, and the fixed frame is located on both sides of the wafers horizontally supported. The detection component includes a signal transceiver part and a matching reflection part, which are installed on the fixed frame. The optical signal output by the signal transceiver part is emitted towards the reflection part, and the reflection part reflects the optical signal to the signal transceiver part. The detection component determines whether a wafer is placed on the support frame according to the optical signal received by the signal transceiver part. The detection component further includes a light shielding plate, which covers the side part of the reflection part. The surface of the light shielding plate is configured with a non-mirror structure to prevent the light emitted by the signal transceiver part from being reflected and interfering with the detection.

Description

Technical Field

[0001] The present invention belongs to the field of semiconductor technology, and more particularly, relates to a wafer-level buffer device. Background Art

[0002] Figure 1 FIG. is a schematic diagram of a prior art wafer-level buffer device, which is configured with support frames arranged in a stacked manner. To control the movement of the handling robot, it is necessary to pre-determine whether a wafer is placed on the support frame.

[0003] Currently, the presence or absence of a wafer is detected by an optical sensor. The optical sensor emits an optical signal towards the wafer, and a reflector is arranged in a matching manner with the optical sensor. The reflector receives the optical signal and emits it back to the optical sensor. If there is a wafer on the support frame, the optical signal is blocked by the wafer, and the reflector cannot receive the optical signal, and correspondingly, the optical sensor cannot receive the reflected optical signal either; if there is no wafer on the support frame, the optical signal is directed towards the reflector and the optical signal is emitted back to the optical sensor.

[0004] During the wafer processing, the optical signal irradiated on the water film of the wafer will be reflected, as Figure 1 shown, the optical signal reflected by the water film may be received by the reflector of an adjacent support frame. This will interfere with the state determination of the adjacent support frame and even cause misjudgment, affecting the normal operation of the transfer robot.

[0005] In addition, due to the low processing accuracy of the reflecting surface, the reflecting surface is likely to form a rough surface. This will cause diffuse reflection on the reflecting surface, thereby affecting the reception degree of the optical signal and interfering with the accuracy of the in-position detection of the wafer. Moreover, the method of determining the in-position detection of the wafer by receiving the optical signal is somewhat single, there is a risk of detection error, and the accuracy of measurement cannot be ensured by means of mutual verification. Summary of the Invention

[0006] The present invention aims to solve at least one of the technical problems existing in the prior art to a certain extent.

[0007] To this end, an embodiment of the present invention provides a wafer-level caching device, which includes a support frame and a detection component. The support frame is used to horizontally support the wafer, and the detection component is disposed on a fixed frame, and the fixed frame is located on both sides of the wafer horizontally supported; the detection component includes a signal transceiver and a matching reflection part, which are installed on the fixed frame. The optical signal output by the signal transceiver is emitted towards the reflection part, and the reflection part reflects the optical signal to the signal transceiver; the detection component determines whether the support frame places the wafer according to the optical signal received by the signal transceiver; the detection component further includes a light-shielding plate, which covers the side of the reflection part; the detection component further includes a light-shielding plate covering the side of the reflection part, and / or further includes a light intensity sensor for detecting the intensity of the optical signal.

[0008] 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.

[0009] As a preferred embodiment, the non-mirror structure includes a plurality of columnar structures extending outward from the side surface of the light-shielding plate, and the columnar structures are uniformly arranged on the surface of the light-shielding plate.

[0010] As a preferred embodiment, the columnar structure is a cylinder, the radius of the cylinder is 0.2-0.5 mm, and its height is less than or equal to 2 mm.

[0011] As a preferred embodiment, the light intensity sensor is disposed on the reflection part and is opposite to the signal transceiver in position to detect the intensity of the optical signal emitted by the signal transceiver.

[0012] As a preferred embodiment, the light intensity sensor is disposed between the reflection part and the light-shielding plate, the light-shielding plate is configured with a light-transmitting hole, and the optical signal of the signal transceiver is incident on the light intensity sensor through the light-transmitting hole.

[0013] As a preferred embodiment, the number of the support frames is at least one, and they are uniformly arranged at intervals along the vertical direction of the fixed frame; the signal transceivers and reflection parts of the detection components configured for adjacent support frames are staggered.

[0014] The beneficial effects of the present invention include:

[0015] In the present invention, a light-shielding plate with a light-transmitting hole is disposed outside the reflection part to prevent the water film on the surface of the wafer from interfering with the detection result; furthermore, a non-mirror structure is configured on the outer side surface of the light-shielding plate to absorb the light emitted by the signal transceiver and avoid its emission from interfering with the detection, thereby improving the detection accuracy; in addition, the signal transceivers and reflection parts of the detection components configured for adjacent support frames are staggered, which is also beneficial to reducing the detection interference, improving the detection accuracy, and ensuring the smoothness of wafer caching and transmission. Description of the Drawings

[0016] Advantages of the present invention will become clearer and easier to understand through the following detailed description in conjunction with the accompanying drawings. These drawings are illustrative only and do not limit the scope of protection of the present invention, where:

[0017] Figure 1 is a schematic diagram of a wafer-level cache device in the prior art;

[0018] Figure 2 is a schematic structural diagram of a wafer-level cache device according to the present invention;

[0019] Figure 3 is a schematic connection diagram of the reflection part and the light shielding plate according to the present invention;

[0020] Figure 4 is a schematic structural diagram of the light shielding plate according to the present invention;

[0021] Figure 5 is Figure 4 the front view of the corresponding light shielding plate;

[0022] Figure 6 is a schematic diagram of another embodiment of the reflection part according to the present invention;

[0023] Figure 7 is a schematic diagram of another embodiment of the light shielding plate according to the present invention;

[0024] Figure 8 is a schematic diagram of a detection component configured with a light intensity sensor according to the present invention;

[0025] Figure 9 is a schematic diagram of another embodiment of a wafer-level cache device according to the present invention. Detailed Embodiments

[0026] The following combines specific embodiments and their accompanying drawings to detail the technical solutions of the present invention. The embodiments recorded herein are specific specific embodiments of the present invention for explaining the concept of the present invention; these explanations are all 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. Except for the embodiments recorded herein, those skilled in the art can also adopt other obvious technical solutions based on the content disclosed in the claims and the specification of this application. These technical solutions include technical solutions that make any obvious substitutions and modifications to the embodiments recorded herein.

[0027] The drawings in this specification are schematic diagrams to assist in explaining the concept of the present invention, schematically showing the shapes of various parts and their mutual relationships. It should be understood that, in order to clearly show the structures of the components in the embodiments of the present invention, the drawings are not drawn in the same proportion, 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 referred to as "Chemical Mechanical Planarization (CMP)", and a wafer is also called a substrate, and their meanings and actual functions are equivalent.

[0029] The structural schematic diagram of a wafer horizontal caching device described in the present invention is as Figure 2 shown. The wafer horizontal caching device 100 includes a support frame 10 and a detection component 20. The support frame 10 is used to horizontally support the wafer, and the detection component 20 is arranged on the outer peripheral side of the support frame 10. Specifically, the detection component 20 is arranged on a fixing frame 30, and the fixing frame 30 is a component for installing the detection component 20; usually, the fixing frames 30 are arranged in pairs on both sides of the support frame 10.

[0030] Figure 2 In the shown embodiment, the number of the support frames 10 is two, and they are stacked in the vertical direction. The distance between adjacent support frames 10 matches the moving space of the transfer manipulator. The top surface of the support frame 10 is provided with a plurality of protruding structures, and the protruding structures are arranged along the outer contour of the wafer to horizontally support the wafer.

[0031] Further, the detection component 20 includes a signal transceiver 21 and a matching reflection part 22. The optical signal output by the signal transceiver 21 is emitted towards the reflection part 22, and the reflection part 22 reflects the optical signal to the signal transceiver 21; the detection component 20 determines whether the support frame 10 is placed with a wafer according to the optical signal received by the signal transceiver 21. Specifically, if the signal transceiver 21 receives the optical signal emitted from the reflection part 22, then the support frame 10 is not placed with a wafer; if the signal transceiver 21 does not receive the optical signal emitted from the reflection part 22, then the support frame 10 is placed with a wafer, because the optical signal is reflected by the wafer on the support frame 10, changing the transmission route and making it impossible to normally irradiate the reflection part 22.

[0032] Figure 2Among them, the optical signal emitted by the signal transceiver unit 21 is represented by a thin solid line. The signal transceiver unit 21 emits the optical signal obliquely towards the plane where the support frame 10 is located, and the inclination angle is less than 10°, so that the emitted light passes through the plane where the wafer is located. As an aspect of this embodiment, the inclination angle formed by the optical signal and the plane where the support frame 10 is located is 5°, so as to control the action range of the optical signal and reduce the interference of the optical signal on other components of the semiconductor device.

[0033] Further, the detection component 20 further includes a light shielding plate 23, which covers the side of the reflection part 22 facing the support frame 10, as Figure 3 shown; the setting of the light shielding plate 23 can block the interference of the inspection components 20 configured on the adjacent support frames 10 on the detection result and ensure the accuracy of the detection. Specifically, since there may be a water film on the surface of the wafer, the optical signal irradiated on the water film may be scattered, and the scattered light irradiates on the reflection part 22 configured on the adjacent support frame 10 and is reflected back to the corresponding signal transceiver unit 21, which will cause misjudgment. That is, if there is a wafer placed on the adjacent support frame 10 and the matching detection component 20 detects the reflected optical signal, it is determined that there is no wafer placed on the support frame 10.

[0034] Figure 1 The detection component 20 shown is configured with a light shielding plate 23, and the light shielding plate 23 can block the interference of the wafers on the adjacent support frames 10 on the detection result and improve the accuracy of the detection component 20.

[0035] Further, the light shielding plate 23 is configured with a light transmission hole 23a, and the optical signal emitted by the signal transceiver unit 21 enters the reflection part 22 through the light transmission hole 23a, and then is emitted from the reflection part 22 to the signal transceiver unit 21 through the light transmission hole 23a. That is, the light shielding plate 23 can filter other interference signals and improve the accuracy of wafer detection.

[0036] Figure 4 is a schematic structural diagram of the light shielding plate of the present invention. The light shielding plate 23 includes a top plate 23b and a boss 23c. The boss 23c is arranged at both ends of the top plate 23b to form a U-shaped structure; the size of the top plate 23b matches the outer shape of the reflection part 22. As an aspect of this embodiment, the height of the boss 23c is 2 mm - 5 mm to control the incidence and reflection of the optical signal of the signal transceiver unit 21 from the light transmission hole 23a.

[0037] As an aspect of this embodiment, the light-transmitting hole 23a is a through hole, which is eccentrically disposed on the top plate 23b of the light-shielding plate 23. The light-transmitting hole 23a is eccentrically arranged, and the main purpose is to irradiate the optical signal emitted by the signal transceiver unit 21 inside the light-transmitting hole 23a, and then the optical signal is reflected from the inside of the light-transmitting hole 23a to the signal transceiver unit 21. That is, the reflection of the optical signal is controlled within a controllable range to improve the detection accuracy.

[0038] Figure 2 The shown wafer horizontal buffer device 100 is configured 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.

[0039] Figure 5 In it, 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 1 mm - 3 mm. Figure 2 In the shown embodiment, the distance between the center of the light-transmitting hole 23a and the horizontal center line of the light-shielding plate 23 is 2 mm. With such a setting, the influence of external interference signals on the detection result can be reduced, and the accuracy of wafer detection can be improved. In the present invention, the size and setting position of the light-transmitting hole 23a are related to the angle of the optical signal emitted by the signal transceiver unit 21, the distance between adjacent support frames 10, and the surface reflection characteristics of the wafer. Therefore, the above factors need to be considered for comprehensive setting.

[0040] 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 a non-metallic material, and the top plate 23b is coated with an anti-reflection coating.

[0041] As an 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 can be understood that in order to avoid the reflection of the optical signal incident on the surface of the light-shielding plate 23 from interfering with the wafer detection, the refractive index of the anti-reflection coating can be between that of air and glass.

[0042] As another aspect of this embodiment, the thickness of the anti-reflection coating is 0.001 mm - 0.1 mm. Preferably, the thickness of the anti-reflection coating is 0.05 mm. The anti-reflection coating is a thin dielectric coating coated on the surface of the light-shielding plate 23 to reduce the reflectivity of the surface to light in a certain wavelength region.

[0043] Specifically, the anti-reflection coating is a substance spin-coated at the interface between the photoresist and the Si substrate to absorb the reflected light during lithography. It mainly includes a bottom anti-reflection coating, a top anti-reflection coating, a developable bottom anti-reflection coating, a spin-coated Si-containing anti-reflection coating, a carbon coating, etc. Among them, the bottom anti-reflection coating is a coating located between the Si substrate and the photoresist, and the bottom anti-reflection coating is mainly composed of a crosslinkable resin, a thermal acid generator, a surfactant, and a solvent combination.

[0044] As a variant of this embodiment, in order to control the emission of optical signals within a limited range to reduce the influence of light reflection on the wafer detection of the adjacent support frame 10, an absorbent layer 22a can be locally coated on the side surface of the reflection part 22, such as Figure 6 shown. The absorbent layer 22a is coated on the outer side of the reflection part 22, which can absorb external interference signals and prevent the optical signals from being reflected to interfere with the wafer detection. That is, only the area where the absorbent layer 22a is not coated is controlled to reflect to improve the detection accuracy.

[0045] Figure 6 In the embodiment shown, the uncoated area of the absorbent layer 22a is a waist-shaped area, which is eccentrically arranged on the side surface of the reflection part 22. The so-called side surface is the plane facing the support frame 10. In some embodiments, the waist-shaped structure is eccentrically arranged on the side surface of the reflection part 22. The distance between the center of the waist-shaped structure and the horizontal midline of the reflection part 22 is 2 mm. Figure 6 The waist-shaped area where the absorbent material is not applied in is represented by a solid line. At this time, the waist-shaped area is not a through hole, and this part of the structure is Figure 5 essentially different from the light-transmitting hole 23a shown in. Figure 5 The light-transmitting hole 23a in is a through hole, and the horizontal projection of the air-permeable hole 23a corresponds to the waist-shaped area of the reflection part 22.

[0046] As an aspect of this embodiment, the absorbent layer 22a can be set to match the wavelength of the optical signal emitted by the signal transceiver 21 to prevent the reflection on the absorbent layer 22a from interfering with the wafer detection. Preferably, the thickness of the absorbent layer 22a is 0.01 - 0.1 mm. The setting of the absorbent layer 22a can reduce the configuration of the light-shielding plate 23, reduce the number of components of the wafer horizontal buffer device, and control the manufacturing and processing cost of the wafer horizontal buffer device.

[0047] It can be understood that in order to strictly control the influence of the reflection of optical signals on the wafer detection, the reflection part 22 configured with the absorbent layer 22a can be used in combination with the light-shielding plate 23 to avoid misjudgment of the wafer detection and prevent mutual interference of the detection components 20.

[0048] As another embodiment of the present invention, a non-mirror structure 23d is disposed on the surface of the light shielding plate 23 to prevent the light emitted by the signal transceiver unit 21 from being reflected and interfering with the detection, thereby improving the accuracy of in-situ wafer detection.

[0049] As an aspect of this embodiment, the non-mirror structure 23d includes a plurality of columnar structures extending outward from the side surface of the light shielding plate, and the columnar structures are uniformly disposed on the surface of the light shielding plate. In some embodiments, the non-mirror structure 23d is a cylinder, as Figure 7 shown, which is uniformly disposed on the surface of the light shielding plate 23; the radius of the cylinder is 0.2 - 0.5 mm, and its height is less than or equal to 2 mm. By setting the light shielding plate 23 in this way, the surface roughness of the light shielding plate 23 can be effectively increased, and the reflection of light can be avoided.

[0050] It can be understood 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 is sandblasted and roughened to increase the surface roughness of the light shielding plate 23 and prevent the light shielding plate 23 from reflecting and affecting the in-situ detection of the wafer.

[0051] As another embodiment of the present invention, the wafer horizontal buffer device further includes a light intensity sensor 24, as Figure 8 shown, and the light intensity sensor 24 is used to detect the optical signal intensity.

[0052] Specifically, the light intensity sensor 24 is disposed on the reflection part 22 and is opposite to the signal transceiver unit 21 in position to detect the intensity of the optical signal emitted by the signal transceiver unit 21. That is, the light intensity sensor 24 is disposed between the reflection part 22 and the light shielding plate 23, and the light shielding plate 23 is configured with Figure 4 a light-transmitting hole 23a as shown, and the optical signal of the signal transceiver unit 21 enters the light intensity sensor 24 through the light-transmitting hole 23a.

[0053] Figure 8 In the embodiment shown, the light intensity sensor 24 can detect the intensity of the optical signal so as to detect whether there is liquid on the wafer surface absorbing the optical signal, and realize the accurate in-situ detection of the wafer.

[0054] In some embodiments, the light intensity sensor 24 can be selected to cooperate with the detection component 20 configured with the light shielding plate 23 to realize the in-situ detection of the wafer.

[0055] Figure 9It is a schematic diagram of another embodiment of a wafer horizontal caching device 100 according to the present invention. In this embodiment, the number of support frames 10 is three, which are evenly spaced along the vertical direction; the signal transceiver parts 21 and the reflection parts 22 of the detection components 20 configured for adjacent support frames 10 are arranged staggeredly. Specifically, the signal transceiver part 21 configured for one support frame 10 is located on the left side, and the matching reflection part 22 is located on the right side; the reflection part 22 configured for the adjacent support frame 10 is located on the left side, and the matching signal transceiver part 21 is located on the right side. The signal transceiver parts 21 configured for adjacent support frames 10 are arranged staggeredly, which to a certain extent avoids the mutual interference of light reflection and improves the accuracy of wafer detection.

[0056] In addition, the wafer horizontal caching device disclosed by the present invention can be applied to a chemical mechanical polishing system. It can be understood that the wafer horizontal caching device described in the present invention can also be applied to other semiconductor devices, such as wafer thinning devices, wafer packaging devices, etc., to solve the problem of unbalanced production beats.

[0057] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "schematic embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0058] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and purposes of the present invention. The scope of the present invention is defined by the claims and their equivalents.

Claims

1. A wafer horizontal caching device, characterized in that, it includes a support frame and a detection component. The support frame is used to horizontally support the wafer. 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 part and a matching reflection part, which are installed on the fixed frame. The optical signal output by the signal transceiver part is emitted towards the reflection part, and the reflection part reflects the optical signal to the signal transceiver part. The detection component determines whether the support frame is placing a wafer according to the optical signal received by the signal transceiver part. The detection component further includes a light-shielding plate covering the side surface of the reflection part, and also includes a light intensity sensor for detecting the intensity of the optical signal; The signal transceiver part obliquely emits the optical signal towards the plane where the support frame is located, and its inclination angle is less than 10°, so that the emitted light passes through the plane where the wafer is located. The light-shielding plate is configured with an eccentric light-transmitting hole, and the projection of the light-transmitting hole towards the reflection part forms a waist-shaped area. An absorbing layer is coated on the outside of the waist-shaped area of the reflection part to absorb external interference signals and prevent the reflection of the optical signal from interfering with the detection of the wafer; The number of the support frames is at least one, and they are evenly spaced along the vertical direction of the fixed frame. The signal transceiver parts and the reflection parts of the detection components configured for adjacent support frames are arranged staggeredly.

2. The wafer horizontal caching device according to claim 1, characterized in that, the surface of the light-shielding plate is configured with a non-mirror structure to prevent the light emitted by the signal transceiver part from being reflected and interfering with the detection accuracy.

3. The wafer horizontal caching device according to claim 2, characterized in that, the non-mirror structure includes a plurality of columnar structures extending outward from the side surface of the light-shielding plate, and the columnar structures are evenly arranged on the surface of the light-shielding plate.

4. The wafer horizontal caching device according to claim 3, characterized in that, the columnar structure is a cylinder, the radius of the cylinder is 0.2 - 0.5 mm, and its height is less than or equal to 2 mm.

5. The wafer horizontal caching device according to claim 1, characterized in that, the light intensity sensor is arranged on the reflection part and is opposite to the signal transceiver part in position to detect the intensity of the optical signal emitted by the signal transceiver part.

6. The wafer horizontal caching device according to claim 1, characterized in that, the light intensity sensor is arranged between the reflection part and the light-shielding plate, and the optical signal of the signal transceiver part is incident on the light intensity sensor through the light-transmitting hole.

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