Wafer Inspection Equipment and Methods

Abstract

This disclosure provides a wafer inspection apparatus and method, relating to the field of semiconductor manufacturing technology. The apparatus includes a base platform, a wafer stage movably disposed on the base platform, a front inspection device disposed above the wafer stage, and a back inspection device disposed below the wafer stage. The back inspection device includes a support portion supporting the wafer, within which a cavity is formed. The cavity is filled with a transparent liquid to wet the outer surface of the blue film on the back side of the wafer. This disclosure eliminates light scattering caused by the frosted texture of the blue film through transparent liquid wetting, and simultaneously prevents sagging by supporting the wafer with the support portion, achieving simultaneous front and back inspection without flipping the wafer. This solves the technical problems of blue film imaging obstacles and automated inspection failures in the prior art.

Description

Technical Field

[0001] This disclosure relates to a wafer inspection device, belonging to the field of semiconductor manufacturing technology. Background Technology

[0002] In the wafer manufacturing and quality inspection process, comprehensive inspection of both the front and back sides of the wafer is an essential step. However, some inspection devices currently on the market have significant limitations, only capable of inspecting one side of the wafer or the other side, and cannot meet the need to inspect both sides simultaneously.

[0003] Meanwhile, during wafer fabrication, after the dicing process, dicing grooves with specific widths and depths are formed on the surface. The microscopic texture of these grooves exhibits irregular, serrated characteristics, and there is a certain probability that defects such as edge chipping and microcracks will occur during the dicing process. Some of these edge chipping and microcracks are hidden on the back side of the wafer, increasing the difficulty of detection. Furthermore, various metal materials are embedded on the wafer surface, and the presence of these metals makes it impossible to simply detect hidden defects on the back side directly from the front side using a microscope.

[0004] The back side of a wafer is typically coated with a blue film, the outer surface of which is designed with a frosted texture. This frosted texture causes light scattering at the interface, severely hindering microscope imaging and making it impossible to clearly obtain image information of the wafer's back side. Although theoretically, wetting with a transparent liquid can reduce light scattering (e.g., by filling the microscopic depressions of the frosted texture using the principle of refractive index matching), existing inspection equipment relies on wafer flipping operations and cannot reliably achieve liquid wetting in automated processes, resulting in this method not being applied to actual production for a long time. Currently, the common method in the industry for detecting defects such as microcracks and edge chipping on the back side of wafers is to first flip the wafer 180° and then inspect the back side with a microscope. However, this method has many problems in actual operation. The surface of the flipped wafer cannot have any support, otherwise it will affect the inspection results, leading to sagging in the middle of the wafer. Since the depth of field of high-magnification objectives is usually only a few micrometers, the wafer sagging makes the image unfocusable, seriously affecting the accuracy and stability of the inspection. Therefore, this method is currently only suitable for manual inspection scenarios and cannot meet the needs of automated and efficient inspection. Therefore, existing technologies cannot solve the imaging problem of blue film, and the sagging problem causes automated detection to fail. There is an urgent need for a device that can achieve high-precision detection of both the front and back sides without flipping. Summary of the Invention

[0005] This disclosure provides a wafer inspection device and method.

[0006] According to one aspect of this disclosure, a wafer inspection apparatus is provided, comprising: a base platform; a wafer stage movably disposed on the base platform for fixing a wafer; a front inspection device disposed above the wafer stage for detecting front defects of the wafer on the wafer stage; and a back inspection device disposed below the wafer stage for detecting back defects of the wafer on the wafer stage, the back inspection device including a support portion for supporting the wafer, the support portion having a cavity formed therein for containing a transparent liquid, the transparent liquid being used to wet the outer surface of a blue film on the back side of the wafer.

[0007] According to one aspect of the technical solution of this disclosure, the wafer inspection equipment, by setting up a front inspection device and a back inspection device, realizes simultaneous inspection of both the front and back sides of the wafer, overcoming the limitation of some existing inspection devices that can only inspect one side of the wafer. Simultaneously, the back inspection device has a cavity within its support section. The transparent liquid filled in the cavity forms a liquid film under surface tension, wetting the outer surface of the blue film on the back side of the wafer. This reduces light scattering at the frosted texture interface, enabling clear acquisition of image information from the back side of the wafer. This overcomes the problem of imaging difficulties caused by the frosted texture of the blue film in existing technologies. Furthermore, it eliminates the need to flip the wafer, and the support section of the back inspection device supports the wafer, preventing wafer sagging from affecting inspection accuracy and stability, thus meeting the requirements for automated and efficient inspection.

[0008] According to at least one embodiment of the wafer inspection apparatus of this disclosure, the back-side inspection device includes: a support head having a through hole inside, the upper end of the hole wall of the through hole forming the support portion for supporting a wafer; a transparent plate made of transparent material disposed within the through hole, the thickness of the transparent plate being less than the depth of the through hole, and the upper surface of the transparent plate being lower than the upper end face of the through hole, so that the cavity is formed between the outer surface of the transparent plate and the inner wall surface of the through hole; an optical module disposed below the support head and facing the transparent plate, for acquiring a back-side image of the wafer located on the support portion through the transparent plate and the cavity; and a moving module disposed on the support head and / or the optical module, for driving the support head and the optical module to move relative to each other to adjust the distance between the optical module and the wafer.

[0009] In this embodiment, a through-hole is provided inside the support head, and a support portion is formed at the upper end of the through-hole wall to support the wafer. A transparent plate is disposed within the through-hole, and its outer surface and the inner wall of the through-hole form a cavity. This structure makes the filling of the cavity and the formation of the liquid film more stable and reliable. The optical module is positioned facing the transparent plate, enabling it to acquire images of the back side of the wafer through the transparent plate and the cavity, ensuring image clarity. The movable module can drive the support head and the optical module to move relative to each other, thereby flexibly adjusting the distance between the optical module and the wafer, facilitating the acquisition of clear images from different positions, and improving the flexibility and accuracy of the inspection.

[0010] According to at least one embodiment of the wafer inspection device of this disclosure, the support head is provided with a liquid injection channel, the liquid injection channel including a liquid injection interface and a first connecting hole connected in sequence, the first connecting hole extending to the cavity; the support head is provided with an annular boss and a water storage tank around the periphery of the through hole, the annular boss forming the support part, the water storage tank being located on the outer periphery of the annular boss and provided with a water-absorbing ring made of water-absorbing material; the support head is also provided with a liquid outlet channel, the liquid outlet channel including a liquid outlet interface and a second connecting hole, one end of the second connecting hole being connected to the water storage tank, and the other end being connected to the liquid outlet interface.

[0011] In this embodiment, the liquid injection channel on the support head injects transparent liquid into the cavity through the liquid injection interface and the first connecting hole, facilitating quick and easy filling of the cavity. The annular boss forms the support portion to support the wafer, ensuring structural stability. The water storage tank and absorbent ring absorb any liquid that may overflow during the testing process, preventing liquid from interfering with the testing. The liquid outlet channel discharges the liquid from the water storage tank through the liquid outlet interface and the second connecting hole, ensuring a clean and stable testing environment and improving the accuracy and reliability of the testing.

[0012] According to at least one embodiment of the wafer inspection apparatus of this disclosure, the support head is provided with a slot around the cavity; the backside inspection device further includes a first liquid return component and a second liquid return component; the first liquid return component is disposed at the lower end of the support head and is provided with a V-groove and a side hole, the V-groove being opposite to the slot, one end of the side hole communicating with the V-groove and the other end extending to the outside of the first liquid return component, the first liquid return component being provided with a first clearance hole opposite to the through hole; the second liquid return component is disposed at the lower end of the first liquid return component and is provided with a square groove and a first drain interface communicating with the square groove, the second liquid return component being provided with a second clearance hole opposite to the first clearance hole; wherein, the optical module acquires an image of the wafer carried on the support through the first clearance hole and the second clearance hole.

[0013] In this embodiment, the support head has slots around the cavity, opposite to the V-shaped groove of the first liquid return component, facilitating liquid flow from the support head into the first liquid return component. Side holes in the first liquid return component drain the liquid to the outside, preventing liquid accumulation within it. A second liquid return component is located at the lower end of the first liquid return component; its square groove and first drain port further collect and drain the liquid, maintaining the cleanliness of the entire inspection device. The placement of the first and second clearance holes allows the optical module to smoothly acquire wafer images without affecting the inspection process, while ensuring coordination between liquid discharge and image acquisition, thus improving the overall performance of the inspection device.

[0014] According to at least one embodiment of the wafer inspection apparatus of the present disclosure, a step is provided at the bottom of the square groove, and a second drain port is provided on the step. The height of the second drain port is higher than that of the first drain port and lower than that of the top of the square groove, and an overflow pipe is connected thereto.

[0015] In this embodiment, a step and a second drain port are provided at the bottom of the square tank. The second drain port is higher than the first drain port but lower than the top of the square tank and is connected to an overflow pipe. This design allows the liquid in the square tank to automatically choose to be discharged from either the first or second drain port depending on the liquid level. When the liquid level is low, the liquid is discharged from the first drain port; when the liquid level is high, the liquid is discharged through the second drain port and the overflow pipe, preventing liquid from overflowing the square tank, ensuring the stability and reliability of liquid discharge, and further maintaining the normal operation of the detection device.

[0016] According to at least one embodiment of the wafer inspection apparatus of this disclosure, the moving module includes a bracket, an adapter block, and a height adjustment shaft connected in sequence. The bracket is disposed at the lower end of the second liquid return component. The height adjustment shaft is used to drive the adapter block, the bracket, the second liquid return component, the first liquid return component, and the support head to move up and down to adjust the distance between the optical module and the wafer. The bracket is provided with a third clearance hole opposite to the position of the first clearance hole.

[0017] In this embodiment, the moving module consists of a bracket, an adapter block, and a height adjustment shaft connected sequentially. The bracket is located at the lower end of the second liquid return component. The height adjustment shaft can drive the adapter block, bracket, second liquid return component, first liquid return component, and support head to move up and down, thereby flexibly adjusting the distance between the optical module and the wafer to meet different testing requirements. The third clearance hole on the bracket is positioned opposite to the first clearance hole, ensuring unobstructed access for the optical module to acquire wafer images and not affecting the testing process. This allows the moving module to achieve height adjustment without affecting the image acquisition function of the entire testing device, improving the flexibility and accuracy of the testing.

[0018] According to at least one embodiment of the wafer inspection apparatus of this disclosure, the wafer inspection apparatus further includes a first driving mechanism and a first height adjustment mechanism disposed between the base platform and the front inspection device, the first driving mechanism and the first height adjustment mechanism being connected to each other and respectively used to drive the front inspection device to move in a first horizontal direction and a vertical direction; the wafer inspection apparatus further includes a second driving mechanism and a second height adjustment mechanism disposed between the base platform and the back inspection device, the second driving mechanism and the second height adjustment mechanism being connected to each other and respectively used to drive the back inspection device to move in a first horizontal direction and a vertical direction; the wafer inspection apparatus further includes a stage driving mechanism disposed between the base platform and the wafer stage, the stage driving mechanism being used to drive the wafer stage to move along a second horizontal direction; wherein, the first horizontal direction and the second horizontal direction are perpendicular to each other.

[0019] In this embodiment, by setting a first driving mechanism and a first height adjustment mechanism between the base platform and the front inspection device, the front inspection device can be driven to move in the first horizontal and vertical directions, adjusting the relative position of the front inspection device and the wafer in the first direction. By setting a second driving mechanism and a second height adjustment mechanism between the base platform and the back inspection device, the back inspection device can be driven to move in the first horizontal and vertical directions, adjusting the relative position of the back inspection device and the wafer in the second direction. A stage driving mechanism is set between the base platform and the wafer stage, driving the wafer stage to move along the second horizontal direction, with the first horizontal direction perpendicular to the second horizontal direction, thus adjusting the relative position of the wafer with the front and back inspection devices in the second direction. This multi-directional driving arrangement allows the wafer inspection equipment to flexibly adjust the positions of the front and back inspection devices relative to the wafer stage, achieving omnidirectional inspection of all areas on both sides of the wafer, improving the comprehensiveness and accuracy of the inspection.

[0020] According to at least one embodiment of the wafer inspection apparatus of this disclosure, the wafer stage includes: a base movably disposed on the base platform and connected to the stage driving mechanism; a stage body movably disposed above the base and provided with a positioning ring for positioning the wafer, a receiving assembly for receiving the positioning ring, and a fixing assembly for fixing the positioning ring; a multi-axis guiding mechanism disposed on the base, the multi-axis guiding mechanism being provided with a guide head, the guide head being connected to the stage body and having a degree of freedom of movement along a first horizontal direction and a second horizontal direction and a degree of freedom of rotation about a vertical axis; a third driving mechanism and a fourth driving mechanism disposed between the base and the stage body, respectively for driving the guide head to move along the first horizontal direction and the second horizontal direction.

[0021] In this embodiment, the wafer stage's base is connected to the stage driving mechanism and is movably mounted on the base platform, enabling overall movement. The stage body places the wafer on the positioning ring via the receiving assembly, and the positioning ring and fixing assembly support and fix the wafer, ensuring its stability during loading and inspection. The guide head of the multi-axis guiding mechanism is connected to the stage body and has degrees of freedom to move along the first and second horizontal directions, as well as degrees of freedom to rotate around the vertical axis. The third and fourth driving mechanisms respectively drive the guide head to move along the first and second horizontal directions, allowing the stage body to flexibly adjust its position and angle, correct the wafer position, and provide a basis for establishing a wafer inspection coordinate system.

[0022] According to one aspect of this disclosure, a wafer inspection method is provided, employing a wafer inspection device, comprising the following steps: fixing a wafer on a wafer stage; supporting the wafer by a support portion and allowing a transparent liquid filled in a cavity to wet the outer surface of a blue film on the back side of the wafer; and detecting front defects and back defects of the wafer by a front inspection device and a back inspection device, respectively.

[0023] According to one aspect of the technical solution of this disclosure, the wafer inspection method utilizes the aforementioned wafer inspection equipment. First, the wafer is fixed on a wafer stage. A support portion supports the wafer, and a transparent liquid within the cavity wets the outer surface of the blue film, solving the problem of imaging difficulties caused by the frosted texture of the blue film. Then, front and back inspection devices are used to inspect defects on both sides of the wafer, achieving simultaneous inspection of both sides without flipping the wafer. Furthermore, the support portion prevents wafer sagging after flipping, avoiding the impact on inspection accuracy and stability. This meets the requirements for automated and efficient inspection, improving both inspection efficiency and accuracy.

[0024] According to at least one embodiment of the wafer inspection method of this disclosure, after fixing the wafer on a wafer stage and before detecting front and back defects of the wafer by a front inspection device and a back inspection device respectively, the method further includes the following steps: driving the wafer stage to move along a second horizontal direction and driving the front inspection device to move along a first horizontal direction to capture multiple feature points on the front side of the wafer, calculating the angular deviation value between the wafer dicing track and the inspection coordinate system, and correcting the position of the wafer stage by a multi-axis guiding mechanism to establish a wafer surface coordinate system; driving the back inspection device to move along the first horizontal direction to below the wafer stage, so that the support head rises to contact and abut against the outer surface of the blue film; adding transparent liquid into the cavity through the liquid injection channel of the support head, so that the transparent liquid wets the blue film. The outer surface; the detection of front and back defects of the wafer by the front and back inspection devices respectively includes the following steps: controlling the back inspection device to move along the scanning path and acquiring a complete image of the back of the wafer through the optical module; driving the front inspection device to move along the first horizontal direction above the wafer stage, and controlling the front inspection device to move along the scanning path to acquire a complete image of the front of the wafer, wherein the blue film drooping status is monitored in real time during the acquisition process, and when the drooping amount exceeds the depth of field of the objective lens, the support head is driven to move synchronously with the movement trajectory of the front inspection device through the moving module to maintain the back of the wafer flat and the surface within the depth of field of the back inspection device; transmitting the front and back images of the wafer to the image processing system for defect detection and comparative analysis.

[0025] In this embodiment, before inspection, the wafer stage and the front inspection device are moved to capture feature points on the front of the wafer, calculate the angle deviation value, correct the position of the wafer stage, and establish a wafer surface coordinate system, providing a foundation for accurate inspection. The back inspection device is moved so that the support head contacts and presses against the outer surface of the blue film. A transparent liquid is added through the injection channel to form a liquid film that wets the blue film, solving the imaging obstacle. During inspection, the back and front inspection devices are controlled to move along the scanning path to acquire complete images of both the front and back sides of the wafer. The drooping state of the blue film is monitored in real time during the acquisition of the front image. When the drooping exceeds the depth of field of the objective lens, the support head is driven to move synchronously with the front inspection device to maintain the back of the wafer flat and within the depth of field of the back inspection device, ensuring the quality of image acquisition. Finally, the front and back images are transmitted to the image processing system for defect detection and comparative analysis, achieving accurate detection and analysis of defects on both sides of the wafer and improving the accuracy and reliability of the inspection. Attached Figure Description

[0026] The accompanying drawings illustrate exemplary embodiments of the present disclosure and, together with the description thereof, serve to explain the principles of the present disclosure. These drawings are included to provide a further understanding of the present disclosure and are incorporated in and constitute a part of this specification.

[0027] Figure 1 This is a perspective view of a back-side detection device according to one embodiment of the present disclosure.

[0028] Figure 2 This is a front view of a back-side detection device according to one embodiment of the present disclosure.

[0029] Figure 3 This is an exploded view of a rear detection device according to one embodiment of the present disclosure.

[0030] Figure 4 This is a schematic diagram of the structure of a back-side detection device according to one embodiment of the present disclosure.

[0031] Figure 5 This is an exploded view of a rear detection device according to one embodiment of the present disclosure.

[0032] Figure 6 yes Figure 4 A schematic diagram of region H in the middle.

[0033] Figure 7 This is an exploded view of a liquid filling module according to one embodiment of the present disclosure.

[0034] Figure 8 This is a top view of a support head according to one embodiment of the present disclosure.

[0035] Figure 9 This is a cross-sectional perspective view of a support head according to one embodiment of the present disclosure.

[0036] Figure 10 This is a schematic diagram of the structure of a first liquid return component according to an embodiment of the present disclosure.

[0037] Figure 11 This is a schematic diagram of the structure of the second liquid return component according to one embodiment of the present disclosure.

[0038] Figure 12 This is a top view of the second liquid return component according to one embodiment of the present disclosure.

[0039] Figure 13 This is a perspective view of a wafer stage according to one embodiment of the present disclosure.

[0040] Figure 14 This is a perspective view of a wafer stage according to one embodiment of the present disclosure.

[0041] Figure 15 This is an exploded view of a first drive mechanism according to one embodiment of the present disclosure.

[0042] Figure 16 This is a perspective view of a second drive mechanism according to one embodiment of the present disclosure.

[0043] Figure 17 This is an exploded view of a first height adjustment mechanism according to one embodiment of the present disclosure.

[0044] Figure 18 This is a perspective view of a stage drive mechanism according to one embodiment of the present disclosure.

[0045] The specific labels in the attached figures are as follows:

[0046] 100 Backside Detection Device

[0047] 110 support head

[0048] 111 Through Hole

[0049] 112 Support section

[0050] 113 cavity

[0051] 114 Injection Port

[0052] 115 First connecting hole

[0053] 116 Annular Boss

[0054] 117 Water Storage Tank

[0055] 117A Water Absorption Ring

[0056] 118 Liquid outlet

[0057] 119 Second connecting hole

[0058] 110A Convex Ring Structure

[0059] 110B slot

[0060] 110C stepped groove

[0061] 120 transparent sheet

[0062] 130 Optical Module

[0063] 131 Microscope

[0064] 131A Objective Lens

[0065] 131B Microscope Mounting Plate

[0066] 140 mobile modules

[0067] 141 bracket

[0068] 141A Third clearance hole

[0069] 142 Adapter Block

[0070] 143 Height Adjustment Shaft

[0071] 150 First return fluid component

[0072] 151 V-groove

[0073] 152 side hole

[0074] 153 First clearance hole

[0075] 154 External Thread Shaft

[0076] 160 Second return fluid component

[0077] 161 square groove

[0078] 162 First drainage port

[0079] 163 Second clearance hole

[0080] 164 steps

[0081] 165 Second drain port

[0082] 166 Overflow pipe

[0083] 167 Annular mounting groove

[0084] 168 Sealing Ring

[0085] 169 Pipeline Interface

[0086] 170 Module Base

[0087] 180 wafers

[0088] 181 Blue Membrane

[0089] 190 Transparent liquid

[0090] 200 Frontal Inspection Device

[0091] 300 wafer stage

[0092] 310 base

[0093] 320 platform main body

[0094] 321 Positioning Circle

[0095] 322 Receiving Assembly

[0096] 322A lifting mast

[0097] 323 Fixing Components

[0098] 324 Multi-axis Guide Mechanism

[0099] 324A Guide Head

[0100] 325 Third Drive Mechanism

[0101] 326 Fourth Drive Mechanism

[0102] 400 base platform

[0103] 500 First drive mechanism

[0104] 501 Marble Pad

[0105] 502 Marble Guide Rail

[0106] 503 Air Float Cup

[0107] 504 Stainless Steel Foot Cup Mounting Plate

[0108] 505 Linear Motor

[0109] 506 Limit Block 1

[0110] 600 Second Drive Mechanism

[0111] 610 Marble base

[0112] 620 X-guide rail

[0113] 630 Linear Motor II

[0114] 640 Mobile Board II

[0115] 650 Limit Block Two

[0116] 700 platform drive mechanism

[0117] 710 Y-guide rail

[0118] 720 Linear Motor Three

[0119] 730 Limit Block 3

[0120] 800 First Height Adjustment Mechanism

[0121] 810 Ball Screw Mechanism

[0122] 820 LM guide rail

[0123] 830 servo motor

[0124] 840 base plate

[0125] 850 side panel

[0126] 860 Nut Seat

[0127] 870 Motor Mounting Plate

[0128] 880 First Moving Board

[0129] 890 Coupling

[0130] 900 Second height adjustment mechanism Detailed Implementation

[0131] The present disclosure will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the disclosure. Furthermore, it should be noted that, for ease of description, only the parts relevant to the present disclosure are shown in the accompanying drawings.

[0132] It should be noted that, where there is no conflict, the embodiments and features described in this disclosure can be combined with each other. The technical solutions of this disclosure will now be described in detail with reference to the accompanying drawings and embodiments.

[0133] Unless otherwise stated, the exemplary implementations / embodiments shown are to be understood as providing exemplary features of various details that provide ways in which the technical concepts of this disclosure can be implemented in practice. Therefore, unless otherwise stated, the features of various implementations / embodiments may be additionally combined, separated, interchanged and / or rearranged without departing from the technical concepts of this disclosure.

[0134] The use of crosshairs and / or shading in the accompanying drawings is generally used to clarify the boundaries between adjacent components. Thus, unless otherwise stated, the presence or absence of crosshairs or shading does not convey or indicate any preference or requirement for the specific material, material properties, dimensions, proportions, commonalities between the illustrated components, or any other characteristics, properties, etc., of the components. Furthermore, in the accompanying drawings, the dimensions and relative dimensions of components may be exaggerated for clarity and / or descriptive purposes. When exemplary embodiments can be implemented differently, a specific process sequence may be performed in a different order than that described. For example, two consecutively described processes may be performed substantially simultaneously or in the reverse order of their description. Furthermore, the same reference numerals denote the same components.

[0135] When a component is referred to as being "on" or "above" another component, "connected to," or "joined to" another component, the component may be directly on, directly connected to, or directly joined to the other component, or there may be intermediate components. However, when a component is referred to as being "directly on" another component, "directly connected to," or "directly joined to" another component, there are no intermediate components. Therefore, the term "connection" can refer to a physical connection, an electrical connection, etc., and may or may not have intermediate components.

[0136] For descriptive purposes, this disclosure may use spatial relative terms such as “below,” “under,” “below,” “down,” “above,” “above,” “higher,” and “side (e.g., in a “sidewall”)” to describe the relationship between one component and another component as shown in the accompanying drawings. In addition to the orientations depicted in the drawings, the spatial relative terms are also intended to encompass different orientations of the device during use, operation, and / or manufacture. For example, if the device in the drawings is flipped, a component described as “below” or “under” another component or feature would subsequently be positioned “above” said other component or feature. Thus, the exemplary term “below” can encompass both “above” and “below” orientations. Furthermore, the device may be otherwise positioned (e.g., rotated 90 degrees or in other orientations), thus interpreting the spatial relative descriptive terms used herein accordingly.

[0137] The terminology used herein is for the purpose of describing particular embodiments and is not intended to be limiting. As used herein, unless the context clearly indicates otherwise, the singular forms “a” and “the” are intended to include the plural forms as well. Furthermore, when the terms “comprising” and / or “including” and variations thereof are used in this specification, it indicates the presence of the stated features, integrals, steps, operations, parts, components, and / or groups thereof, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, parts, components, and / or groups thereof. It should also be noted that, as used herein, the terms “substantially,” “about,” and other similar terms are used as approximate terms rather than as terms of degree, thus explaining the inherent biases in measurements, calculated values, and / or provided values ​​that would be recognized by one of ordinary skill in the art.

[0138] Current market testing devices have limitations, only capable of inspecting either the front or back of a wafer, unable to inspect both sides simultaneously. After wafer dicing, the surface has dicing marks, resulting in defects such as chipping and microcracks, some hidden on the back side. Furthermore, the presence of metallic material on the wafer surface increases the difficulty of inspecting back-side defects from the front. The frosted texture of the blue film on the back of the wafer causes light scattering, hindering microscope imaging. Existing equipment relies on wafer flipping, which cannot reliably achieve liquid wetting to reduce scattering and has not been applied in actual production. Common industry methods for back-side wafer inspection require a 180° flip, causing the wafer to droop in the middle, affecting image focusing. This method is only suitable for manual inspection and is difficult to automate or achieve high efficiency. Current technologies cannot solve the blue film imaging obstacle and automated inspection failure problems; therefore, there is an urgent need for equipment that can simultaneously perform high-precision inspection of both front and back sides without flipping.

[0139] To address the aforementioned technical problems, this embodiment provides a wafer inspection device.

[0140] Figure 1 This is a perspective view of a back-side detection device according to one embodiment of the present disclosure. Figure 2 This is a front view of a back-side detection device according to one embodiment of the present disclosure. Figure 3 This is an exploded view of a rear detection device according to one embodiment of the present disclosure.

[0141] See Figures 1 to 3 As shown, the wafer inspection equipment of this embodiment includes: a back inspection device 100, a front inspection device 200, a wafer stage 300, and a base platform 400.

[0142] Figure 4 This is a schematic diagram of the structure of a back-side detection device according to one embodiment of the present disclosure. Figure 5 This is an exploded view of a rear-side detection device according to one embodiment of the present disclosure. Figure 6 yes Figure 4 A schematic diagram of region H in the middle. Figure 7 This is an exploded view of a liquid filling module according to one embodiment of the present disclosure.

[0143] See Figures 4 to 7 As shown, the back detection device 100 of this embodiment includes a liquid filling module and an optical module 130. The liquid filling module includes components such as a support head 110, a transparent plate 120, and a moving module 140.

[0144] Figure 8 This is a top view of a support head according to one embodiment of the present disclosure.

[0145] See Figure 6 and Figure 8As shown, the support head 110 has a through hole 111 inside, which is used for the optical path of the optical module 130 to pass through. The upper end of the through hole 111 forms a support portion 112 for supporting the wafer 180.

[0146] The transparent plate 120 is made of a transparent material and is disposed within the through hole 111. The thickness of the transparent plate 120 is less than the depth of the through hole 111, meaning its upper surface is located inside the through hole 111 and is lower than the upper end face of the through hole 111. This forms a cavity 113 between the outer surface of the transparent plate 120 and the inner wall surface of the through hole 111, which is used to contain the transparent liquid 190. The transparent plate 120 can be an existing glass plate.

[0147] like Figure 5 and Figure 6 As shown, the optical module 130 is positioned facing the transparent plate 120 and is used to acquire a back-side image of the wafer 180 located on the support portion 112 through the transparent plate 120 and the cavity 113. The optical module 130 can be an existing microscope 131 with microscopic imaging function, which is fixed to the module base plate 170 by a microscope mounting plate 131B, with its objective lens 131A positioned opposite to the through hole 111.

[0148] like Figure 4 and Figure 7 As shown, the moving module 140 is disposed on the support head 110 and / or the optical module 130, and is used to drive the support head 110 and the optical module 130 to move relative to each other, so as to adjust the distance between the optical module 130 and the wafer 180. That is, the moving module 140 can drive at least one of the support head 110 and the optical module 130 to move, so that the bottom surface of the wafer 180 is always within the depth of field of the optical module 130.

[0149] The overall concept of this embodiment is as follows: the wafer 180 is placed face up on the support portion 112 of the support head 110, with the blue film adhered to its back side facing the cavity 113 formed between the transparent plate 120 and the through hole 111; after injecting transparent liquid 190 into the cavity 113, the liquid fills the micro-uneven structure on the surface of the blue film 181, eliminating diffuse reflection of light and transforming the blue film 181 from a frosted state to an optically transparent state; the optical module 130 acquires an image of the back side of the wafer 180 through the transparent plate 120 and the liquid, effectively solving the problem of unclear image acquisition caused by the blue film 181, and improving the accuracy and reliability of back side defect detection of the wafer 180. The wafer 180 is placed on the support portion 112 of the support head 110, which provides stable and reliable support for the wafer 180, preventing the wafer 180 from sag due to its own weight. In this way, driven by the moving module 140, the optical module 130 can accurately adjust the distance between itself and the wafer 180, so that the bottom surface of the wafer 180 is always within the depth of field of the optical module 130, thereby enabling clear imaging of the back side of the wafer 180 and achieving high-magnification, high-precision automated detection of back side defects without flipping the wafer 180.

[0150] Figure 9 This is a cross-sectional perspective view of a support head according to one embodiment of the present disclosure.

[0151] See Figure 6 and Figure 9 As shown, the transparent plate 120 can be disposed in the through hole 111 of the support head 110 in the following manner: the inner wall of the through hole 111 is provided with a stepped groove 110C, the outer periphery of the transparent plate 120 is embedded in the stepped groove 110C, and the lower surface of the transparent plate 120 abuts against the step surface of the stepped groove 110C to form axial limiting and radial constraint.

[0152] like Figure 6 and Figure 9As shown, to facilitate the injection of a transparent solution into the cavity 113, the support head 110 is provided with an injection channel. The injection channel includes an injection port 114 and a first connecting hole 115 connected in sequence, with the first connecting hole 115 extending into the cavity 113. An injection connector can be installed on the injection port 114, which is connected to an injection device via a pipe. The injection device injects the transparent liquid 190 into the cavity 113. When it is necessary to inject the transparent liquid 190 into the cavity 113, the injection device is connected to the injection port 114. The transparent liquid 190 enters the first connecting hole 115 through the injection port 114, and then flows into the cavity 113 through the first connecting hole 115, thereby realizing the injection operation of the transparent liquid 190 into the cavity 113. During testing, after placing the wafer 180 in the support 112, the transparent liquid 190 can be injected into the cavity 113 through the liquid injection channel, without having to pre-inject the transparent liquid 190 before placing the wafer 180. This makes the operation more convenient and allows the transparent liquid 190 to stably and fully fill the micro-uneven structure on the surface of the blue film 181, thereby improving the accuracy and stability of the test.

[0153] like Figure 6 and Figure 9 As shown, during the acquisition of images of the back side of wafer 180, images of different areas on the back side of wafer 180 can be acquired by controlling the relative movement of wafer 180 with respect to this device. During the movement of wafer 180, residual liquid on the back side of wafer 180 may drip onto the electrical components of the device, causing damage. To solve this problem, the support head 110 is provided with an annular boss 116 and a water storage tank 117 surrounding the through hole 111. The annular boss 116 forms the support part 112, supporting wafer 180 during inspection and scraping away residual liquid on the back side of wafer 180 during its movement. The water storage tank 117 is annular, and an absorbent ring 117A made of absorbent material is provided inside. The absorbent ring 117A is located on the outer periphery of the annular boss 116 and can be a microporous absorbent ring 117A or other existing annular components with absorbent function. The support head 110 is also equipped with a liquid outlet channel, which includes a liquid outlet interface 118 and a second connecting hole 119. One end of the second connecting hole 119 is connected to the water storage tank 117, and the other end is connected to the liquid outlet interface 118. When liquid overflows from the cavity 113 or there is excess liquid on the surface of the blue film 181, the annular boss 116 can scrape the residual liquid on the back side of the wafer 180 onto the absorbent ring 117A. The absorbent ring 117A can absorb the scraped liquid, preventing the liquid remaining on the back side of the wafer 180 from dripping and damaging electrical components, and can also solve the problem of air bubbles remaining in the water film. At the same time, if it is necessary to drain the liquid, a water pump or other liquid pumping equipment can be connected through the liquid outlet interface 118, so that the liquid is discharged from the liquid outlet interface 118 to the outside of the equipment through the absorbent ring 117A and the second connecting hole 119, keeping the detection device clean and operating normally, and improving the reliability and stability of the detection.

[0154] like Figure 9 As shown, in some embodiments of the support head 110, the support head 110 is also provided with a convex ring structure 110A. The convex ring structure 110A is annular, and a water storage tank 117 is formed on its inner side, which is also used to support the wafer 180.

[0155] Figure 10 This is a structural schematic diagram of a first liquid return component according to one embodiment of the present disclosure. Figure 11 This is a schematic diagram of the structure of the second liquid return component according to one embodiment of the present disclosure. Figure 12 This is a top view of the second liquid return component according to one embodiment of the present disclosure.

[0156] See Figure 6 , Figure 10 , Figure 11 and Figure 12 As shown, to facilitate the collection and discharge of transparent liquid 190 overflowing from the cavity 113 and scraped off by the annular boss 116, the support head 110 is provided with a slot 110B around the cavity 113. The back-side detection device 100 also includes a first liquid return component 150 and a second liquid return component 160. The slot 110B is used to collect the transparent liquid 190 overflowing from the cavity 113 and scraped off by the annular boss 116. The first liquid return component 150 is located at the lower end of the support head 110 and is provided with a V-shaped groove 151 and a side hole 152. The V-shaped groove 151 is positioned opposite to the slot 110B and is located below the slot 110B. It can be an annular structure with a V-shaped cross-section. The V-shaped groove 151 is used to receive the transparent liquid 190 falling from the slot 110B. One end of the side hole 152 communicates with the V-groove 151, and the other end extends to the outside of the first return liquid component 150, for discharging the transparent liquid 190 in the V-groove 151. The second return liquid component 160 is disposed at the lower end of the first return liquid component 150, and is provided with a square groove 161 and a first drain port 162 communicating with the square groove 161. The transparent liquid 190 overflowing from the cavity 113 is discharged sequentially through the groove hole 110B, the V-groove 151, the side hole 152, the square groove 161 and the first drain port 162, forming a stepped return liquid path. At the same time, the first return liquid component 150 is provided with a first clearance hole 153 opposite to the position of the through hole 111, and the second return liquid component 160 is provided with a second clearance hole 163 opposite to the position of the first clearance hole 153. That is to say, when the through hole 111, the first clearance hole 153 and the second clearance hole 163 are round holes, the three are coaxial. When inspecting the back side of wafer 180, optical module 130 acquires an image of wafer 180 supported on support portion 112 through first clearance hole 153 and second clearance hole 163.

[0157] like Figure 11 and Figure 12As shown, in some embodiments of the second liquid return component 160, a step 164 is provided at the bottom of the square tank 161, and a second drain port 165 is provided on the step 164. The height of the second drain port 165 is higher than that of the first drain port 162 and lower than that of the top of the square tank 161, and it is connected to an overflow pipe 166. When the liquid level in the square tank 161 rises to a certain height due to blockage of the first drain port or excessive liquid inflow, exceeding the second drain port 165, the liquid will be discharged from the second drain port 165 through the overflow pipe 166, forming a secondary drain mechanism to prevent liquid from overflowing the square tank 161, avoiding damage to the detection device, and improving the reliability and safety of the device.

[0158] like Figure 7 and Figure 12 As shown, in order to integrate the above-mentioned structure for conveying and discharging the transparent liquid 190 onto the device, the second return component 160 is also provided with two pipe interfaces 169. One pipe interface 169 is connected to the connector on the injection interface 114 via a pipe fitting and a hose, and the other pipe interface 169 is connected to the connector on the discharge interface 118 via a pipe fitting and a hose. Simultaneously, the first and second discharge ports are also respectively provided with connectors, through which hoses are connected to discharge the transparent liquid 190.

[0159] In one embodiment where the first return fluid component 150 is disposed at the lower end of the support head 110, an internal thread is provided on the inner side of the through hole 111 to form an internal thread hole. The first return fluid component 150 is provided with an external thread shaft 154 adapted to the internal thread hole in the middle of the V-groove 151. The external thread shaft 154 is connected to the inner side of the internal thread hole by a thread, and the first clearance hole 153 passes through the external thread shaft 154.

[0160] In one embodiment where the second return liquid component 160 is disposed at the lower end of the first return liquid component 150, the second return liquid component 160 is provided with an annular mounting groove 167 surrounding the second clearance hole 163, and a sealing ring 168 is disposed in the annular mounting groove 167; the first return liquid component 150 is fixedly disposed on the upper end face of the second return liquid component 160, and is sealed and fitted with the second return liquid component 160 through the sealing ring 168.

[0161] In one embodiment of the movable module 140, the movable module 140 includes a bracket 141, an adapter block 142, and a height adjustment shaft 143 connected in sequence. The bracket 141 is disposed at the lower end of the second liquid return component 160. The height adjustment shaft 143 is used to drive the adapter block 142, the bracket 141, the second liquid return component 160, the first liquid return component 150, and the support head 110 to move up and down, thereby adjusting the distance between the optical module 130 and the wafer 180. The bracket 141 is L-shaped and has a third clearance hole 141A opposite to the position of the first clearance hole 153. The height adjustment shaft 143 drives the adapter block 142 to move up and down, causing the bracket 141, the liquid return component, and the support head 110 to move as a whole. The third clearance hole 141A is coaxial with the first / second clearance holes, ensuring that the optical path of the optical module 130 is unobstructed.

[0162] It is understood that the moving module 140 may also use existing devices such as a lifting mechanism or a linear moving module 140 that can drive the support head 110 and the optical module 130 to move relative to each other.

[0163] like Figure 1 and Figure 2 As shown, the front inspection device 200 is disposed above the wafer stage 300 and is used to inspect front defects of the wafer on the wafer stage 300. The aforementioned front inspection device 200 can be an existing device with image acquisition function, such as a microscope, and is disposed facing the wafer stage 300.

[0164] See Figures 1 to 3 As shown, the wafer inspection equipment also includes a first drive mechanism 500 and a first height adjustment mechanism 800 disposed between the base platform 400 and the front inspection device 200. The first drive mechanism 500 and the first height adjustment mechanism 800 are interconnected. The first drive mechanism 500 drives the front inspection device 200 to move along a first horizontal direction, and the first height adjustment mechanism 800 drives the front inspection device 200 to move up and down. The wafer inspection equipment also includes a second drive mechanism 600 and a second height adjustment mechanism 900 disposed between the base platform 400 and the back inspection device 100. The second drive mechanism 600 and the second height adjustment mechanism 900 are interconnected and are used to drive the back inspection device to move in the first horizontal direction and the vertical direction, respectively. The wafer inspection equipment also includes a stage drive mechanism 700 disposed between the base platform 400 and the wafer stage 300. The stage drive mechanism 700 drives the wafer stage to move along a second horizontal direction; wherein, the first horizontal direction and the second horizontal direction are perpendicular to each other. In the figure, the first horizontal direction and the second horizontal direction are respectively exemplified by the X-axis direction and the Y-axis direction. The first height adjustment mechanism 800 and the second height adjustment mechanism 900 mentioned above can use a height adjustment shaft or an existing lifting module.

[0165] Figure 13This is a perspective view of a wafer stage according to one embodiment of the present disclosure. Figure 14 This is a perspective view of a wafer stage according to one embodiment of the present disclosure.

[0166] like Figure 13 and Figure 14 As shown, the wafer stage 300 includes: a base 310, a stage body 320, a multi-axis guiding mechanism 324, a third driving mechanism 325, and a fourth driving mechanism 326. The base 310 is movably disposed on the base platform 400 and connected to the stage driving mechanism 700. The stage body 320 is movably disposed above the base 310 and is provided with a positioning ring 321 for positioning the wafer, a receiving assembly 322 for receiving the positioning ring 321, and a fixing assembly 323 for fixing the positioning ring 321. The fixing assembly 323 can be an existing gripper assembly, such as a pneumatic gripper. The receiving assembly 322 can use an existing lifting mechanism and has several lifting rods 322A that can be raised and lowered. The base 310 has clearance holes for the lifting rods 322A. When the lifting rods 322A rise, they receive the positioning ring 321, and when they fall, they place the positioning ring 321 on the stage body 320. A multi-axis guiding mechanism 324 is disposed on the base 310. The multi-axis guiding mechanism 324 is equipped with a guide head 324A, which is rotatably connected to the platform body 320 and has degrees of freedom of movement along a first horizontal direction and a second horizontal direction, as well as a degree of freedom of rotation about a vertical axis. A third drive mechanism 325 and a fourth drive mechanism 326 are disposed between the base 310 and the platform body 320, respectively used to drive the guide head 324A to move along the first horizontal direction and the second horizontal direction, enabling each multi-axis guiding mechanism 324 to automatically adjust its displacement and rotation angle. The base 310 moves in the X-axis direction via the platform drive mechanism 700, the guide head 324A moves in the X-axis direction via the third drive mechanism 325, and moves in the Y-axis direction via the fourth drive mechanism 326, driving the platform body 320 to rotate, thus achieving position correction. The multi-axis guiding mechanism 324 can use an existing XYθ-axis guiding module. The beneficial effects of this structure are as follows: the multi-axis guiding mechanism 324 enables the stage body 320 to make fine adjustments in the three degrees of freedom of X, Y, and θ, accurately correcting the angular deviation between the wafer dicing track and the detection coordinate system; the positioning ring 321 and the fixing component 323 ensure that the wafer remains stable during the detection process, preventing image blurring caused by vibration; this design aligns the wafer through precise coordinate system correction, preparing it for wafer position correction.

[0167] Figure 17 This is an exploded view of a first height adjustment mechanism according to one embodiment of the present disclosure.

[0168] like Figure 17As shown, in one embodiment of the first height adjustment mechanism 800, the first height adjustment mechanism 800 comprises a ball screw mechanism 810, an LM guide rail 820, a servo motor 830, a base plate 840, three side plates 850, a nut seat 860, a motor mounting plate 870, a first movable plate 880, and a coupling 890. The base plate 840, three side plates 850, nut seat 860, and motor mounting plate 870 are connected to form a mounting frame. The servo motor 830 is mounted on the motor mounting plate 870 and connected to the ball screw mechanism 810 via the coupling 890. The movable plate 880 is connected to the ball screw mechanism 810 via the nut seat 860. The LM guide rail 820 is connected to the nut seat 860 and is used to guide the movable plate 880. During installation, the movable plate 880 is connected to the driven component, such as a front detection device. It is understood that the second height adjustment mechanism 900 can use the same mechanism as the first height adjustment mechanism 800 to achieve the height adjustment function.

[0169] Figure 15 This is an exploded view of a first drive mechanism according to one embodiment of the present disclosure.

[0170] like Figure 15 As shown, in one embodiment of the first drive mechanism 500, it comprises a marble pad 501, a marble guide rail 502, several air-floating feet 503, four foot mounting plates 504, a linear motor 505, and a limiting block 506, used to drive the front detection device to move along the X-axis. The marble pad 501 is mounted on the base platform 400, the marble guide rail 502 is mounted on the marble pad 501, and the foot mounting plates 504 are interconnected and used to mount the air-floating feet 503, which provide support. The linear motor 505 is mounted on the marble pad 501 and drives the foot mounting plates 504 to move along the marble guide rail 502. The limiting block 506 is mounted on one side of the marble guide rail 502 to limit the maximum travel distance. During installation, one of the foot mounting plates 504 is connected to the first height adjustment mechanism 800.

[0171] Figure 16 This is a perspective view of a second drive mechanism according to one embodiment of the present disclosure.

[0172] like Figure 16As shown, in one embodiment of the second drive mechanism 600, the second drive mechanism 600 comprises a marble base 610, an X-axis guide rail 620, a second linear motor 630, a second moving plate 640, and a second limiting block 650, and is used to drive the back detection device to move along the X-axis direction. The second linear motor 630 and the X-axis guide rail 620 are mounted on the marble base 610. The second moving plate 640 is connected to the second linear motor 630 and the second height adjustment mechanism 900, and is guided by the X-axis guide rail 620. The second limiting block 650 restricts the travel of the second moving plate 640.

[0173] Figure 18 This is a perspective view of a stage drive mechanism according to one embodiment of the present disclosure.

[0174] like Figure 18 As shown, the stage drive mechanism 700 consists of a Y-axis guide rail 710, a linear motor 720, and a limiting block 730, used to drive the wafer stage to move along the Y-axis. The Y-axis guide rail 710 and the linear motor 720 are mounted on the base platform 400. The linear motor 720 drives the base 310 of the wafer stage 300 to move, and the limiting block 730 limits the travel distance of the base 310.

[0175] This embodiment provides a wafer inspection method using the aforementioned wafer inspection equipment, including the following steps: fixing the wafer on a wafer stage; supporting the wafer with a support portion and allowing the transparent liquid filling the cavity to wet the outer surface of the blue film on the back side of the wafer; and detecting front and back defects of the wafer using a front inspection device and a back inspection device, respectively.

[0176] Specifically, the wafer inspection method includes the following steps:

[0177] Step 1: Fix the wafer onto the wafer carrier.

[0178] Step 2: Drive the wafer stage along the second horizontal direction through the stage driving mechanism, and drive the front detection device along the first horizontal direction through the first driving mechanism. The front detection device captures multiple feature points on the front side of the wafer. Calculate the angular deviation between the wafer dicing track and the detection coordinate system. Drive the stage body to move through the third and fourth driving mechanisms, and guide it through the multi-axis guiding mechanism to correct the wafer position and establish the wafer surface coordinate system.

[0179] Step 3: Drive the back-side detection device along the first horizontal direction to the underside of the wafer via the second drive mechanism; drive the support head to rise to contact and press against the outer surface of the blue film on the backside of the wafer.

[0180] Step 4: Add transparent liquid into the cavity through the injection channel. Under the action of surface tension, the transparent liquid forms a liquid film and wets the outer surface of the blue film, eliminating light scattering.

[0181] Step 5: Control the back-side inspection device to move along the scanning path and acquire a complete image of the back side of the wafer through the optical module.

[0182] Step 6: Drive the front detection device along the first horizontal direction to move it above the front of the wafer using the first driving mechanism; control the front detection device to move along the scanning path and acquire a complete image of the front of the wafer; during the acquisition process, monitor the sag of the blue film on the wafer in real time. When the sag exceeds the depth of field of the objective lens, drive the support head to support the wafer using the second height adjustment mechanism, and drive the support head to move synchronously with the movement trajectory of the front detection device using the second driving mechanism to maintain the flatness of the back of the wafer. A master-slave control algorithm can be used, where the movement module of the back detection device receives the movement trajectory signal of the front detection device and synchronously adjusts the position of the support head at the same speed and direction.

[0183] Step 7: Transmit the front and back images to the image processing system for defect detection and comparative analysis.

[0184] Among them, the front and back inspections of wafers can be performed separately or simultaneously, which is suitable for different inspection scenarios.

[0185] Real-time monitoring of the blue film sagging status on the wafer can be achieved by detecting the acquired images or by acquiring the surface topography data of the blue film in real time through a laser displacement sensor mounted on the support head, calculating the sagging amount and comparing it with the objective lens depth of field threshold.

[0186] The above wafer inspection methods are compatible with both front and back inspection, avoiding the cumbersome operation of flipping the wafer required by traditional methods. By supporting the wafer with a support and moving synchronously with the front inspection device, the droop during inspection is less than the depth of field of the objective lens. At the same time, the standardization and automation of the through-film inspection process are realized, the inspection efficiency is improved, and an efficient and reliable solution is provided for quality control in the wafer manufacturing process.

[0187] In the description of this specification, the references to terms such as "one embodiment / mode," "some embodiments / modes," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment / mode or example is included in at least one embodiment / mode or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment / mode or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments / modes or examples. Furthermore, without contradiction, those skilled in the art can combine and integrate the different embodiments / modes or examples described in this specification, as well as the features of different embodiments / modes or examples.

[0188] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0189] Those skilled in the art should understand that the above embodiments are merely for illustrating the present disclosure and are not intended to limit the scope of the disclosure. Those skilled in the art can make other changes or modifications based on the above disclosure, and these changes or modifications still fall within the scope of the present disclosure.

Claims

1. A wafer inspection device, characterized in that, include: Base platform; A wafer stage is movably disposed on the base platform for fixing the wafer; A front-side inspection device is disposed above the wafer stage and is used to detect front-side defects of the wafer on the wafer stage; A back-side inspection device is disposed below the wafer stage and is used to inspect back-side defects of the wafer. The back-side inspection device includes a support portion for supporting the wafer, and a cavity for containing a transparent liquid is formed within the support portion. The transparent liquid is used to wet the outer surface of the blue film on the back side of the wafer. The back-side inspection device includes: a support head with a through-hole inside, the upper end of the through-hole wall forming the support portion for supporting the wafer; a transparent plate made of transparent material and disposed within the through-hole, the upper surface of the transparent plate being lower than the upper end face of the through-hole, so that a cavity is formed between the outer surface of the transparent plate and the inner wall surface of the through-hole; an optical module disposed below the support head and facing the transparent plate, for acquiring a back-side image of the wafer located on the support portion through the transparent plate and the cavity; and a moving module disposed on the support head and / or the optical module, for driving the support head and the optical module to move relative to each other to adjust the distance between the optical module and the wafer. The support head is provided with a liquid injection channel, which includes a liquid injection port and a first connecting hole connected in sequence, the first connecting hole extending to the cavity; the support head is provided with an annular boss and a water storage tank around the through hole, the annular boss forming the support part, the water storage tank being located on the outer periphery of the annular boss and provided with a water-absorbing ring made of absorbent material; the support head is also provided with a liquid outlet channel, which includes a liquid outlet port and a second connecting hole, one end of the second connecting hole being connected to the water storage tank, and the other end being connected to the liquid outlet port.

2. The wafer inspection equipment according to claim 1, characterized in that, The support head is provided with slots around the cavity; The back-side detection device further includes a first liquid return component and a second liquid return component; The first liquid return component is disposed at the lower end of the support head and is provided with a V-groove and a side hole. The V-groove is opposite to the groove hole. One end of the side hole is connected to the V-groove and the other end extends to the outside of the first liquid return component. The first liquid return component is provided with a first clearance hole opposite to the through hole. The second liquid return component is disposed at the lower end of the first liquid return component, and is provided with a square groove and a first liquid discharge interface communicating with the square groove. The second liquid return component is provided with a second clearance hole that is opposite to the position of the first clearance hole. The optical module acquires an image of the wafer supported on the support portion through the first clearance hole and the second clearance hole.

3. The wafer inspection equipment according to claim 2, characterized in that, The bottom of the square tank is provided with a step, and the step is provided with a second drain port. The height of the second drain port is higher than that of the first drain port and lower than that of the top of the square tank, and it is connected to an overflow pipe.

4. The wafer inspection equipment according to claim 2, characterized in that, The movable module includes a bracket, an adapter block, and a height adjustment shaft connected in sequence. The bracket is located at the lower end of the second liquid return component. The height adjustment shaft is used to drive the adapter block, bracket, second liquid return component, first liquid return component, and support head to move up and down to adjust the distance between the optical module and the wafer. The bracket is provided with a third clearance hole that is opposite to the position of the first clearance hole.

5. The wafer inspection equipment according to claim 1, characterized in that, The wafer inspection equipment further includes a first drive mechanism and a first height adjustment mechanism disposed between the base platform and the front inspection device. The first drive mechanism and the first height adjustment mechanism are connected to each other and are used to drive the front inspection device to move in a first horizontal direction and a first vertical direction, respectively. The wafer inspection equipment further includes a second drive mechanism and a second height adjustment mechanism disposed between the base platform and the back inspection device. The second drive mechanism and the second height adjustment mechanism are connected to each other and are used to drive the back inspection device to move in the first horizontal direction and the first vertical direction, respectively. The wafer inspection equipment also includes a stage driving mechanism disposed between the base platform and the wafer stage, the stage driving mechanism being used to drive the wafer stage to move along a second horizontal direction; Wherein, the first horizontal direction and the second horizontal direction are perpendicular to each other.

6. The wafer inspection equipment according to claim 5, characterized in that, The wafer stage includes: The base is movably mounted on the base platform and connected to the platform drive mechanism; The stage body is movably disposed above the base and is provided with a positioning ring for positioning the wafer, a receiving component for receiving the positioning ring, and a fixing component for fixing the positioning ring. The multi-axis guide mechanism is provided on the base. The multi-axis guide mechanism is provided with a guide head. The guide head is connected to the platform body and has the degree of freedom to move along the first horizontal direction and the second horizontal direction and the degree of freedom to rotate about the vertical axis. The third and fourth drive mechanisms, located between the base and the platform body, are used to drive the guide head to move along the first and second horizontal directions, respectively.

7. A wafer inspection method, characterized in that, The wafer inspection equipment according to any one of claims 1-6 includes the following steps: Fix the wafer on the wafer carrier; The wafer is supported by a support portion, and the transparent liquid filling the cavity wets the outer surface of the blue film on the back of the wafer. The front and back defects of the wafer are detected by a front inspection device and a back inspection device, respectively.

8. The wafer inspection method according to claim 7, characterized in that, After the wafer is fixed on the wafer stage, and before the front and back defects of the wafer are detected by the front inspection device and the back inspection device respectively, the following steps are also included: The wafer stage is driven to move along the second horizontal direction, and the front detection device is driven to move along the first horizontal direction to capture the feature points on the front of the wafer, calculate the angular deviation between the wafer dicing track and the detection coordinate system, and correct the position of the wafer stage through the multi-axis guiding mechanism to establish the wafer surface coordinate system. The back-side detection device is driven to move along the first horizontal direction to below the wafer stage, so that the support head rises to contact and press against the outer surface of the blue film; A transparent liquid is added into the cavity through the injection channel of the support head, so that the transparent liquid wets the outer surface of the blue film; The process of detecting front-side and back-side defects of the wafer using a front-side inspection device and a back-side inspection device respectively includes the following steps: The back-side detection device is controlled to move along the scanning path, and a complete image of the back side of the wafer is acquired through the optical module; Drive the front detection device to move along the first horizontal direction to above the wafer stage, control the front detection device to move along the scanning path to acquire a complete image of the front of the wafer, and when the droop exceeds the depth of field of the objective lens, drive the support head to move synchronously with the movement trajectory of the front detection device to maintain the back of the wafer flat and the surface within the depth of field of the back detection device. The front and back images of the wafer are transmitted to an image processing system for defect detection and comparative analysis.

Images