Semiconductor manufacturing system, measuring device, and semiconductor manufacturing method

Abstract

A semiconductor manufacturing system, a measuring device and a semiconductor manufacturing method are disclosed. The semiconductor manufacturing system includes an etching tool and a measuring device. The etching tool is used to carry a first wafer and to process a first back surface of the first wafer. The measuring device is disposed in the etching tool. The measuring device includes a camera and a controller. The camera is used to capture an image of the first back surface of the first wafer. The controller is used to receive the image to determine whether the first back surface processed by the etching tool is over-etched and to generate an over-etch signal. Thus, the semiconductor manufacturing system of the present application can timely determine whether the back surface of the wafer is over-etched.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a semiconductor manufacturing system, and more particularly to a semiconductor manufacturing system for detecting over-etching, a measuring device and a semiconductor manufacturing method. BACKGROUND

[0002] During semiconductor manufacturing, wafer cleaning techniques are used to remove unwanted materials that can cause yield loss for subsequent semiconductor processes. Wafer cleaning steps are repeated many times throughout the manufacturing process in order to remove particles, contaminants, residues. Wet etching techniques are used for selective removal of residues, wafer cleaning and etching applications.

[0003] However, the acid solution of the etching cleaning machine can contaminate other liquids during the recycling process. If the contaminated liquid is used to etch the backside of the wafer, resulting in over-etching, the subsequent photolithography process on the front side of the wafer cannot be performed due to the unevenness of the wafer backside, which prevents the wafer from being placed flat, causing the exposure machine to fail to focus successfully. Therefore, timely detection of over-etching of the wafer backside is a problem to be solved in the art. SUMMARY

[0004] The present disclosure aims to provide a semiconductor manufacturing system, a measuring device and a semiconductor manufacturing method, which can timely detect whether the backside of a wafer is over-etched.

[0005] One embodiment of the present disclosure relates to a semiconductor manufacturing system, which comprises an etching tool and a measuring device. The etching tool is configured to carry a first wafer and process a first backside of the first wafer. The measuring device is disposed in the etching tool. The measuring device comprises a camera and a controller. The camera is configured to capture an image of the first backside of the first wafer. The controller is configured to receive the image to determine whether the first backside processed by the etching tool is over-etched and generate an over-etching signal.

[0006] In one embodiment of the present disclosure, the semiconductor manufacturing system further comprises a host. The host is configured to control the etching tool to stop processing a second backside of a second wafer according to the over-etching signal, wherein the second backside of the second wafer is processed by the etching tool after the first wafer is processed by the etching tool.

[0007] In one embodiment of the present application, the semiconductor manufacturing system further comprises a wafer sensor, a rotation sensor, and a relay circuit. The wafer sensor is used to sense whether the first wafer is carried by the robot next to the measuring device by light, and the wafer sensor generates a wafer sensing signal if the first wafer is carried by the robot. The rotation sensor is used to sense whether the robot is rotated to an angle, wherein the robot carries the first wafer and rotates the first wafer to the angle, and the first back surface is in the shooting range of the camera. The relay circuit is electrically connected to the controller, and is used to receive the wafer sensing signal and the rotation sensing signal. The relay circuit controls the controller to determine whether the first wafer is over-etched if the robot is rotated to the angle and the rotation sensor generates the rotation sensing signal; and the relay circuit receives the wafer sensing signal and the rotation sensing signal.

[0008] In one embodiment of the present application, wherein the etching tool is used to etch the first back surface of the first wafer to remove a plurality of thin films formed on the first back surface when processing the first front surface of the first wafer.

[0009] In one embodiment of the present application, wherein the controller is used to calculate a plurality of differences between the color of each of a plurality of pixels of the first back surface in the image and an average value, and determine whether the first back surface is over-etched according to the plurality of differences; wherein the average value is calculated by the colors of a plurality of normal wafers.

[0010] In one embodiment of the present application, the semiconductor manufacturing system further comprises a light emitting element. The light emitting element is used to continuously emit light to the first wafer to reflect the light to the camera.

[0011] One embodiment of the present application relates to a measuring device disposed in an etching tool. The etching tool is used to process a first back surface of a first wafer, and the measuring device comprises a camera and a controller. The camera is used to shoot an image of the first back surface of the first wafer. The controller is used to receive the image to determine whether the first back surface processed by the etching tool is over-etched, and generate an over-etching signal.

[0012] One embodiment of the present application relates to a semiconductor manufacturing method, which comprises the following steps. A first wafer is carried by an etching tool, and a first back surface of the first wafer is processed by the etching tool; an image of the first back surface of the first wafer processed by the etching tool is shot; whether the first back surface processed by the etching tool is over-etched is determined according to the image; and the etching tool is controlled to stop processing a second back surface of a second wafer if the first back surface is over-etched, wherein the second back surface of the second wafer is processed by the etching tool after the first wafer is processed by the etching tool.

[0013] In one embodiment of the present application, wherein processing the first back surface of the first wafer comprises the following steps. Etching the first back surface by an etching tool to remove a plurality of thin films formed on the first back surface when processing the first front surface of the first wafer.

[0014] In one embodiment of the present application, wherein determining whether the first back surface is over-etched comprises the following steps. Calculating a plurality of differences between a color of each of a plurality of pixels of the first back surface in the image and an average value, wherein the average value is calculated from colors of a plurality of normal wafers, and determining whether the first back surface is over-etched according to the plurality of differences.

[0015] Compared with the prior art, the semiconductor manufacturing system, the measuring device and the semiconductor manufacturing method according to the present application can timely find whether the back surface of the wafer is over-etched. BRIEF DESCRIPTION OF DRAWINGS

[0016] Aspects of the embodiments of the application can be best understood with reference to the following detailed description when considered in connection with the accompanying drawings. It should be noted that various features are not drawn to scale in the drawings. In fact, the dimensions of the various features can be arbitrarily increased or decreased for clarity. Like reference numerals can be used to denote like features throughout the specification and figures.

[0017] Figure 1 A block diagram of a semiconductor manufacturing system according to some embodiments of the present application is shown.

[0018] Figure 2 A top view of an etching tool according to some embodiments of the present application is shown.

[0019] Figure 3 A cross-sectional view of an etching cleaning machine in an etching tool according to some embodiments of the present application is shown.

[0020] Figure 4 A block diagram of a semiconductor manufacturing system according to some embodiments of the present application is shown.

[0021] Figure 5 A schematic diagram of a measuring device and an etching tool according to some embodiments of the present application is shown.

[0022] Figure 6A And Figure 6B A schematic diagram of a robot arm in an etching tool according to some embodiments of the present application is shown.

[0023] Figure 7A And Figure 7B A circuit diagram of a relay circuit in a measuring device according to some embodiments of the present application is shown.

[0024] Figure 7C And Figure 7D A circuit diagram of a relay circuit in a measuring device according to some embodiments of the present application is shown.

[0025] Figure 8 A schematic view of a wafer backside is depicted in accordance with some embodiments of the present application.

[0026] Figure 9 A flowchart of a semiconductor manufacturing method is depicted in accordance with some embodiments of the present application.

[0027] Figure 10 A cross-sectional view of a wafer is depicted in accordance with some embodiments of the present application.

[0028] Figure 11 A cross-sectional view of a wafer is depicted in accordance with some embodiments of the present application.

[0029] Figure 12 A cross-sectional view of a wafer is depicted in accordance with some embodiments of the present application.

[0030] Main reference numerals explanation:

[0031] 100 - semiconductor manufacturing system, 120 - etching tool, 121 - load element, 122 - robot, 123 - robot, 124 - robot, 125 - etch cleaner, 140 - measuring device, 141 - controller, 142 - camera, 143 - light emitting element, 144 - relay circuit, 144a - relay unit, 144b - relay unit, 144c - relay unit, 144d - relay unit, 145 - wafer sensor, 146 - rotation sensor, 147 - wafer sensor, 148 - rotation sensor, 160 - arithmetic device, 162 - computer, 163 - host computer, 400 - wafer, 410 - calculation range, 430 - thin film, 432 - thin film, 434 - thin film, CHK - chuck, DSP1 - dispenser, DSP2 - dispenser, DSP3 - dispenser, DSP4 - dispenser, DL1 - recovery layer, DL2 - recovery layer, DL3 - recovery layer, TANK1 - tank, TANK2 - tank, DRN1 - drain pipe, DRN2 - drain pipe, IS - image signal, WS - wafer sensing signal, RS - rotation sensing signal, WS1 - wafer sensing signal, WS2 - wafer sensing signal, RS1 - rotation sensing signal, RS2 - rotation sensing signal, OES - over-etching signal, PL - shutter, GND - ground, +24VDC - 24V DC output, S1 - step, S2 - step, S3 - step, S4 - step, S5 - step, S6 - step, S7 - step. DETAILED DESCRIPTION

[0032] The following disclosure provides many different embodiments, or examples, for implementing various characteristics of the provided subject matter. Specific examples of components and arrangements are described below to simplify the present disclosure. These are, of course, merely examples and are not intended to limit the scope of the present application in any way. For instance, the formation of a first feature over or on a second feature in the description that follows can include embodiments where the first and second features are formed in direct contact, and can also include embodiments where additional features can be formed between the first and second features, such that the first and second features do not form direct contact. In addition, the present application can repeat reference numerals and / or letters in various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and / or configurations discussed.

[0033] The terminology used in the description of the application herein, including the examples discussed herein, is for the purpose of describing particular embodiments and is not intended to limit the application. There is, of course, an implied limitation that the materials, conditions, and the like are such that will conform to the recreational use of the application. The description herein is specifically made with reference to the examples provided, but these are only examples and are not intended to limit the scope of the application or the language of the claims.

[0034] With respect to the term "coupled" or "connected" as used herein, it is intended to mean a mechanical or electrical connection, either direct B indirect, between or among two or more elements.

[0035] For example, during the manufacturing of semiconductor wafers, contaminants (e.g., particles, metallic impurities, organic contaminants, and naturally occurring oxide layers) on the wafers can reduce the yield of the production wafers. Therefore, before and after the wafers are subjected to semiconductor processes (e.g., exposure, etching, ion implantation, thermal treatment, etc.), the wafers are cleaned by wet cleaning to remove unwanted contaminants and films on the front side or back side of the wafers. Different solutions are used to clean the wafers for different contaminants.

[0036] Reference Figure 1 . Figure 1A block diagram of a semiconductor manufacturing system 100 is illustrated according to some embodiments of the present invention. In some embodiments, the semiconductor manufacturing system 100 includes an etching tool 120, a measuring device 140, and a computing device 160. The etching tool 120 is used to clean a wafer 400, for example, by wet cleaning to remove unwanted contaminants and films from the front or back side of the wafer. The measuring device 140 measures the etched wafer 400 and determines whether the wafer 400 is abnormal. If the measuring device 140 determines that the wafer 400 is abnormal, the measuring device 140 sends a signal to the computing device 160 in the factory. The computing device 160 controls the etching tool 120 to stop operating. In some embodiments, the computing device 160 is a desktop computer, workstation, laptop computer, tablet computer, industrial computer, server, or a combination thereof.

[0037] In some embodiments, the etching tool 120 operates at room temperature and pressure, also known as operating in an atmospheric environment. It should be understood that various possible variations and options of the operating environment of the etching tool 120 are within the consideration and scope of these embodiments. For example, in some embodiments, the etching tool 120 operates in a high-temperature, low-pressure environment (e.g., temperature above room temperature and pressure below atmospheric pressure).

[0038] refer to Figure 2 . Figure 2 This is a top view of an etching tool 120 illustrated according to some embodiments of the present invention. In some embodiments, the etching tool 120 includes a carrier element 121, a robotic arm 122, a robotic arm 123, a robotic arm 124, and an etching cleaning machine 125. In some embodiments, the robotic arm 122 is capable of three-axis movement and rotation at any angle, such as the x, y, and z axes of a Cartesian coordinate system. In some embodiments, in a semiconductor process, after another machine (not shown) has performed exposure, etching, ion implantation, or thermal treatment processes on the wafer 400, the other machine can deliver the wafer 400 onto the carrier element 121 of the etching tool 120. The robotic arm 122 is used to support and transport the wafer 400 to various different positions (e.g., transporting the wafer 400 to the position of the robotic arm 123). The robotic arm 123 is used to receive the wafer 400 transported from the robotic arm 122, and the robotic arm 123 can be used to flip the wafer face, for example, flipping the wafer from face up to face down. Robotic arm 124 is used to transfer the wafer 400 carried on robotic arm 123 to etching and cleaning machine 125.

[0039] For example, after processing the front side of a wafer (etching, ion implantation, heat treatment, etc.), not only are process products formed on the front side of the wafer, but process contaminants or thin films are also left on the back side of the wafer. Therefore, wafer 400 is sent to etching tool 120 to clean the back side of the wafer.

[0040] In some embodiments, the etching tool 120 is used to clean the backside of the wafer, and the robot 122 is used to transfer the wafer, which was originally front-side up, from the carrier element 121 to the robot 123. The robot 123 is used to rotate 180 degrees to flip the wafer. After the robot 123 flips the wafer, the wafer is front-side down and the wafer is backside up. In one embodiment, the upper two of the four grippers of the robot 124 transfer the wafer from the upper robot 123 to one of the upper two of the plurality of etch cleaners 125. Correspondingly, the lower two of the four grippers of the robot 124 transfer the wafer from the lower robot 123 to one of the lower two of the plurality of etch cleaners 125. Figure 2 The number of etch cleaners 125 is only an example. Various different numbers of etch cleaners 125 are within the scope of embodiments of the present application.

[0041] The manner in which the etching tool 120 transfers the wafer is only an example. In other embodiments, the etching tool 120 is not limited to including Figure 2 The robots 122, 123, and 124 shown are examples. For example, the robot 123 can directly transfer the wafer to the etch cleaners 125, or the robot 122 can directly rotate the wafer and hand it to the robot 124. In addition, the configuration of the etching tool 120 is only an example. Various different etching tools 120 are within the scope of embodiments of the present application. In other embodiments, the etching tool 120 further includes an ultrasonic cleaning device (not shown).

[0042] For example, after processing the front side of the wafer, contaminants are present on the backside of the wafer. The etching tool 120 is used to etch the backside of the wafer using nitric acid (HNO3). However, the etch cleaner 125 used leaks the nitric acid (HNO3) to the recovery layer of other etching solutions when recovering the etching solution by centrifugal force. Using contaminated or misproportioned etching solution increases or decreases the etching rate of the material on the backside of the wafer being cleaned. If the backside of the wafer is over-etched due to the increased etching rate, the backside of the wafer is not flat, and the wafer cannot be properly placed for exposure due to the non-flat backside of the wafer.

[0043] Reference Figure 3 . Figure 3A cross-sectional view of an etch cleaning machine 125 in an etching tool 120 is illustrated according to some embodiments of the present application. In some embodiments, the etch cleaning machine 125 includes a chuck CHK, a dispenser DSP1, a dispenser DSP2, a dispenser DSP3, a dispenser DSP4, a recovery layer DL1, a recovery layer DL2, a recovery layer DL3, a tank TANK1, a tank TANK2, a drain DRN1, and a drain DRN2. The chuck CHK is used to place a wafer. The dispenser DSP1 is used to inject nitrogen gas to dilute the gas generated by the etch cleaning machine 125 cleaning the wafer, and the excess gas is drained through the side or the drain DRN1. The dispenser DSP2 is used to inject deionized water (DI water) to the wafer on the chuck CHK. The dispenser DSP3 is used to inject nitric acid (HNO3) to the wafer on the chuck CHK. The dispenser DSP4 is used to inject hydrofluoric acid (HF) to the wafer on the chuck CHK. An operator of the etching tool 120 can inject different solutions to clean the backside of the wafer according to the target film to be cleaned on the backside of the wafer. The chuck CHK is moved up and down to maintain the same height as the recovery layer to which the particular solution belongs. For example, the dispenser DSP2 injects deionized water (DI water), the chuck CHK is maintained at the height of the recovery layer DL1 and continuously rotates to spin the deionized water (DI water) to the recovery layer DL1 to drain the deionized water (DI water) through the drain DRN2. For example, the dispenser DSP3 is used to inject nitric acid (HNO3), the chuck CHK is maintained at the height of the recovery layer DL2 and continuously rotates to spin the nitric acid (HNO3) to the recovery layer DL2 to recover the nitric acid (HNO3) to the tank TANK1 so that the nitric acid (HNO3) can be used in the next cleaning process. For example, the dispenser DSP4 is used to inject hydrofluoric acid (HF), the chuck CHK is maintained at the height of the recovery layer DL3 and continuously rotates to spin the hydrofluoric acid (HF) to the recovery layer DL3 to recover the hydrofluoric acid (HF) to the tank TANK2 so that the hydrofluoric acid (HF) can be used in the next cleaning process. However, when the chuck CHK is maintained at the height of the recovery layer DL2 and continuously rotates, the nitric acid (HNO3) on the chuck CHK can leak the nitric acid (HNO3) to the recovery layer DL3 through the gap between the chuck CHK and the recovery layer DL2, resulting in the tank TANK2 belonging to the hydrofluoric acid (HF) containing the hydrofluoric acid (HF) and the nitric acid (HNO3). Since the hydrofluoric acid (HF) in the tank TANK2 is mixed with the nitric acid (HNO3), the etching rate of the hydrofluoric acid (HF) in the tank TANK2 is affected. It should be noted that the solutions used (e.g., deionized water (DI water) and hydrofluoric acid (HF)) are examples only and are not limited thereto. In other embodiments, an operator of the etching tool 120 cleans contaminants on the backside of the wafer by a solution (e.g., ammonia (NH4OH) or hydrogen peroxide (H2O2)).

[0044] In standard practice, maintenance personnel periodically measure the thickness of the thin film on both unetched and etched wafers to ensure the etching rate of the recycled etching solution is within the normal range. However, periodic etching rate measurements cannot immediately confirm whether the etching solution has been contaminated by other solutions. If the etching solution is contaminated and not detected in time, the number of failed wafers can be substantial.

[0045] Compared to the above approach, in this embodiment of the invention, the measuring device 140 is disposed in the etching tool 120 to determine whether the back side of the etched wafer has been over-etched. Since the surface of an over-etched wafer is uneven, the color reflected from the wafer is uneven. The measuring device 140 determines whether the color difference is too large based on the image of the back side of the wafer to detect whether the wafer has been over-etched in a timely manner. The method for calculating the color difference on the back side of the wafer will be explained in the following embodiments. Figure 8 Further explanation is available.

[0046] refer to Figure 4 . Figure 4 Block diagrams of a semiconductor manufacturing system 100 are illustrated according to some embodiments of the present invention. In some embodiments, the measuring device 140 includes a controller 141, a camera 142, a light-emitting element 143, a relay circuit 144, a wafer sensor 145, and a rotation sensor 146. The controller 141 controls the camera 142 to continuously capture images. The camera 142 continuously transmits an image signal IS to the controller 141, and the controller 141 determines whether the color is abnormal based on the image signal IS captured from the back of the wafer. When the camera 142 needs to capture images, the controller 141 also controls the light-emitting element 143 to continuously emit light, so that the camera 142 can receive sufficient light from the back of the wafer. The wafer sensor 145 and the rotation sensor 146 are used to sense whether the wafer has reached the measurement position. When the wafer reaches the measurement position, the relay circuit 144 sends a corresponding signal to control the controller 141 to judge the captured image signal IS. The sensing methods of the wafer sensor 145 and the rotation sensor 146 will be discussed in subsequent embodiments. Figure 6A and Figure 6B Further explanation is provided. In other embodiments, wafer sensor 145 and rotation sensor 146 may be integrated onto a specific robotic arm of etching tool 120 (e.g., one of robotic arm 123, robotic arm 124, or robotic arm 125) and coupled to relay circuit 144 in measuring device 140. In another embodiment, wafer sensor 145, rotation sensor 146, and relay circuit 144 may be integrated into etching tool 120, and relay circuit 144 may be coupled to controller 141 in measuring device 140.

[0047] Please refer to Figure 5 . Figure 5 A schematic diagram of the measurement device 140 and the etching tool 120 is shown according to some embodiments of the present application. In some embodiments, the measurement device 140 is used to determine whether the backside of the wafer is over-etched after the wafer has completed the etching process. The robot 124 is used to transfer the etched wafer from the etch cleaner 125 to the robot 123. The camera 142 is disposed below the robot 123. The robot 123 is rotated 180 degrees to flip the wafer. After the robot 123 flips the wafer, the front side of the wafer is facing up and the backside of the wafer is facing down, so that the camera 142 can take a picture of the backside of the wafer. The disposition of the measurement device 140 is only an example, and is not limited thereto. In some embodiments, the measurement device 140 is disposed in the etch cleaner 125 and determines the wafer after the wafer is etched. In some other embodiments, the measurement device 140 is disposed next to the robot 122 and determines the wafer after the wafer is transferred from the robot 123 to the robot 122.

[0048] The disposition of the elements in the measurement device 140 described above is only an example. Various different dispositions of the elements in the measurement device 140 are within the scope of the embodiments of the present application. For example, in various embodiments, when the camera 142 and the light emitting element 143 are disposed in the robot 123, the robot 122, the etch cleaner 125, or a combination thereof, the controller 141, the relay circuit 144, or a combination thereof are also disposed in the robot 123, the robot 122, the etch cleaner 125, or a combination thereof.

[0049] Please refer to Figure 6A and Figure 6B . Figure 6A and Figure 6B A schematic diagram of the robot 123 in the etching tool 120 is shown according to some embodiments of the present application. As shown in Figure 6A , in some embodiments, a wafer sensor 145 is disposed in the robot 123 and is used to sense whether the robot 123 is carrying a wafer by light. When the robot 123 is carrying a wafer, the position of the wafer will block the light path of the wafer sensor 145, so that the light sensed by the wafer sensor 145 decreases. At this time, the wafer sensor 145 can generate a wafer sensing signal WS. A rotation sensor 146 is disposed next to the robot 123, and the rotation sensor 146 is used to sense whether the robot 123 is rotated to an angle. As shown in Figure 6BAs shown, when the robot arm 123 rotates 180 degrees, the shutter PL in the robot arm 123 rotates with the robot arm 123 and finally blocks the light beam of the rotation sensor 146, so that the rotation sensor 146 senses the light beam to decrease and generates a rotation sensing signal RS. The relay circuit 144 is electrically connected to the controller 141 and is used to receive the wafer sensing signal WS and the rotation sensing signal RS. When the robot arm 123 carries the wafer and rotates 180 degrees so that the back surface of the wafer faces downward, the back surface of the wafer is in the shooting range of the camera 142. Accordingly, when the relay circuit 144 receives the wafer sensing signal WS and the rotation sensing signal RS at the same time, the relay circuit 144 sends a control signal to trigger the controller 141 to determine whether the back surface of the wafer is over-etched according to the image signal IS received from the camera 142. When the controller 141 determines that the back surface of the wafer is over-etched, the controller 141 generates an over-etching signal OES. The operation mode of the relay circuit 144 will be described in the following embodiments Figure 7A Further description is provided.

[0050] Please refer to Figure 4 . The operation device 160 includes a computer 162 and a host 163. The computer 162 is used to receive and store the image signal IS from the controller 141, and receive the over-etching signal OES to transmit to the host 163. When the host 163 receives the over-etching signal OES, it indicates that the etching solution has been contaminated, and using the contaminated etching solution to clean the back surface of other wafers will possibly cause the wafers to be over-etched or damaged. Therefore, the host 163 is used to control each of the plurality of etching cleaning machines 125 in the etching tool 120 to immediately stop cleaning the back surface of the wafer. In other embodiments, the host 163 is used to control each of the plurality of etching cleaning machines 125 in the etching tool 120 to stop working after cleaning the current wafer. In other embodiments, the host 163 is used to control one of the plurality of etching cleaning machines 125 in the etching tool 120 to stop working.

[0051] In an embodiment, assuming that the upper and lower robot arms 123 in the etching tool 120 synchronously receive the respective wafers, and the two wafers are flipped together for measurement, in some embodiments, the relay circuit 144 is used to detect whether one of the wafers in one of the robot arms 123 (for example, the upper robot arm 123 or the lower robot arm 123) reaches the measurement position, and when the relay circuit 144 determines that one of the wafers reaches the measurement position, it can be inferred that the respective wafers of the two robot arms 123 have reached the measurement position, so that the controller 141 is triggered to measure the two wafers in the upper and lower robot arms 123.

[0052] Reference is made to Figure 7A and Figure 7B . Figure 7A and Figure 7BA circuit diagram of a relay circuit 144 in a measuring device 140 is shown according to some embodiments of the present invention. In some embodiments, such as Figure 7A As shown, relay circuit 144 includes relay unit 144a and relay unit 144b. Relay circuit 144 is connected to ground terminal GND and 24V DC output terminal +24VDC to respond to signals from wafer sensor 145 and rotation sensor 146. In some embodiments, relay unit 144a and relay unit 144b are solid-state relays. When relay unit 144a does not receive wafer sensing signal WS, relay unit 144a is not conducting. Figure 7B As shown, when relay unit 144a receives the wafer sensing signal WS, the light-emitting diode of relay unit 144a emits light, and the optocoupler of relay unit 144a conducts. Similarly, when relay unit 144b does not receive the rotation sensing signal RS, relay unit 144b is not conducting. Figure 7B As shown, when relay unit 144b receives the rotation sensing signal RS, the light-emitting diode of relay unit 144b generates light, and the optocoupler of relay unit 144b is turned on. When the optocouplers of relay unit 144a and relay unit 144b are turned on simultaneously, relay circuit 144 is used to trigger controller 141 to perform color difference judgment on the back side of the wafer. In other embodiments, relay units 144a and 144b are not limited to solid-state relays. Relay units 144a and 144b can be electromagnetic relays, reed relays, or combinations thereof.

[0053] In one embodiment, it is assumed that the upper and lower robotic arms 123 in the etching tool 120 do not synchronously transport the wafer and carry the wafer at different points in time. The relay circuit 144 is used to determine whether the wafer has reached the measurement position on the two robotic arms 123 for measurement.

[0054] refer to Figure 7C and Figure 7D . Figure 7C and Figure 7D Circuit diagrams of relay circuit 144 in measuring device 140 are illustrated according to some embodiments of the present invention. In one embodiment, wafer sensors 145 and 147 are respectively disposed on the upper robotic arm 123 and the lower robotic arm 123 of etching tool 120, and wafer sensors 145 and 147 are coupled to relay circuit 144. Rotation sensors 146 and 148 are respectively disposed beside the upper robotic arm 123 and the lower robotic arm 123 of etching tool 120, and rotation sensors 146 and 148 are coupled to relay circuit 144.Figure 7D As shown, relay unit 144a is used to receive the wafer sensing signal WS1 from wafer sensor 145. Relay unit 144b is used to receive the rotation sensing signal RS1 from rotation sensor 146. Relay unit 144c is used to receive the wafer sensing signal WS2 from wafer sensor 147. Relay unit 144d is used to receive the rotation sensing signal RS2 from rotation sensor 148. The above-mentioned method of receiving the wafer sensing signal WS to turn on relay unit 144a and receiving the rotation sensing signal RS to turn on relay unit 144b also applies to wafer sensing signals WS1, rotation sensing signals RS1, wafer sensing signals WS2 and rotation sensing signals RS2. Therefore, the method by which wafer sensing signals WS1, rotation sensing signals RS1, wafer sensing signals WS2 and rotation sensing signals RS2 turn on relay units 144a, 144b, 144c and 144d will not be described in detail here. Accordingly, when the optocouplers of relay unit 144a and relay unit 144b are simultaneously turned on, the relay circuit 144 triggers the controller 141 to perform color difference judgment on the back side of the wafer corresponding to the upper robotic arm 123 in the etching tool 120. When the optocouplers of relay unit 144c and relay unit 144d are simultaneously turned on, the relay circuit 144 triggers the controller 141 to perform color difference judgment on the back side of the wafer corresponding to the lower robotic arm 123 in the etching tool 120.

[0055] exist Figure 7D In this embodiment, relay units 144a and 144b are turned on, while relay units 144c and 144d are not turned on, which can trigger controller 141 to control the upper robotic arm 123 in the etching tool 120. In addition, the wafer of the lower robotic arm 123 in the etching tool 120 has not yet reached the measurement position.

[0056] refer to Figure 8 . Figure 8A schematic diagram of the backside of a wafer is shown according to some embodiments of the present application. In some embodiments, the controller 141 calculates a color difference of the backside of the wafer 400 from the calculated range 410 of the backside of the wafer 400 taken by the camera 142. Specifically, the controller 141 compares the difference between the color of each of all the pixels in the calculated range 410 and a preset average value, and calculates the sum of the difference between each of all the pixels and the preset average value to obtain a damage value. Thus, the controller 141 determines whether the damage value is greater than a preset damage threshold. If the result is that the damage value is greater than the preset damage threshold, it indicates that the wafer is over-etched. In an embodiment, the controller 141 calculates the preset average value from the colors of the images of a plurality of normal wafers previously obtained to obtain the color of a normal wafer. In an embodiment, the preset damage threshold is adjusted by a detection tolerance. If the detection tolerance is low, the user sets a lower preset damage threshold. Even if the wafer 400 in Figure 8 does not show any material, it should be understood by those skilled in the art that the wafer 400 has patterns and / or films on the backside during the semiconductor manufacturing process.

[0057] In other embodiments, the controller 141 calculates an average value of the colors of each of all the pixels in the calculated range 410, and compares the difference between the color of each of all the pixels in the calculated range 410 and the average value to calculate the sum of the difference between each of all the pixels and the average value, and the sum is the damage value. Also, the controller 141 determines whether the damage value is greater than a preset damage threshold. If the result is that the damage value is greater than the preset damage threshold, it indicates that the wafer is over-etched.

[0058] Reference is made to Figure 9 . Figure 9 A flowchart of a semiconductor manufacturing method according to some embodiments of the present application is shown. The method 900 includes steps S1-S7. The steps S1-S7 can be applied to the semiconductor manufacturing system 100 shown in the block diagram, but are not limited thereto. For the sake of clarity, the semiconductor manufacturing method described below is described in conjunction with the semiconductor manufacturing system 100 shown in the block diagram. Figure 4 . Figure 9 The semiconductor manufacturing method described below is described in conjunction with the semiconductor manufacturing system 100 shown in the block diagram. Figure 2 , Figure 5 , Figure 8 , Figure 10 , Figure 11 , Figure 12 .

[0059] In step S1, the wafer 400 is placed on the carrier element 121, and is sequentially transferred by the robot arm 122, the robot arm 123, and the robot arm 124 to the etch cleaning machine 125. The transfer method of the wafer 400 is described in Figure 2 , and is not described herein. Reference is made to Figure 10 . Figure 10A cross-sectional view of wafer 400 is shown according to some embodiments of the present application. Figure 10 Thin film 434, thin film 432 and thin film 430 on wafer 400 are formed of different materials. Etch cleaning machine 125 performs etching chemical reaction on thin film 434 on wafer 400.

[0060] In some embodiments, etch cleaning machine 125 is used to etch metal on wafer 400. In some other embodiments, etch cleaning machine 125 is used to etch alloy on wafer 400. In alternative embodiments, etching process is used to etch insulator on wafer 400. The materials etched by the above-mentioned etching process are only exemplary. Materials etched by various etch cleaning machines 125 are within the scope of embodiments of the present application.

[0061] In step S2, controller 141 controls camera 142 to continuously take pictures, and controls light emitting element 143 to continuously emit light, so as to increase the brightness of the light irradiated on the back surface of wafer 400. The arrangement of camera 142 and light emitting element 143 is as shown in Figure 5 , which will not be repeated here.

[0062] In step S3, robot arm 124 transfers wafer 400 to robot arm 123. Robot arm 123 carries wafer 400 and rotates it by 180 degrees, so that the back surface of wafer 400 faces downward and is within the photographing range of camera 142.

[0063] In step S4, relay circuit 144 triggers controller 141 to judge whether the received image signal IS indicates that the back surface of wafer 400 is over-etched. The operation method of relay circuit 144 is as shown in Figure 7A and Figure 7B , which will not be repeated here. Please refer to Figure 11 . Figure 11 A cross-sectional view of wafer 400 is shown according to some embodiments of the present application. If controller 141 judges that wafer 400 is not over-etched (for example, in Figure 11 , target thin film 434 is removed, and thin film 432 and thin film 430 still exist), the flow goes to step S5. Please refer to Figure 12 . Figure 12 A cross-sectional view of wafer 400 is shown according to some embodiments of the present application. If controller 141 judges that wafer 400 is over-etched (for example, in Figure 12 , target thin film 434 is removed, and thin film 432 and thin film 430 are also partially removed, and the back surface of wafer 400 is uneven and the image of the back surface of wafer 400 has color difference), the flow goes to step S6.

[0064] In other embodiments, the thin film 434, the thin film 432 and the thin film 430 on the wafer 400 are sequentially and planarly removed using different etching solutions for different materials, and the controller 141 judges that there is no over-etching on the back side of the wafer, and the flow proceeds to step S5.

[0065] In step S5, the controller 141 does not generate the over-etching signal OES. Therefore, the host 163 does not control the etching tool 120 to stop working. The etching cleaning machine 125 in the etching tool 120 continues the current cleaning program.

[0066] In step S6, the controller 141 generates the over-etching signal OES and transmits it to the computer 162. The computer 162 transmits the over-etching signal OES to the host 163. The host 163 controls the etching tool 120 to stop working according to the over-etching signal OES.

[0067] In step S7, the etching solution in the recycling layer and the pipeline is discharged and replaced with new etching solution several times to ensure that the etching solution in the recycling layer and the pipeline is not mixed with other solutions.

[0068] The above outlines the features of several embodiments so that those skilled in the art can better understand the embodiments of the present application. Those skilled in the art should understand that the present application can be easily used as a basis for designing or modifying other processes and structures to achieve the same purposes and / or achieve the same advantages as the embodiments described herein. Those skilled in the art should also recognize that such equivalent structures do not deviate from the spirit and scope of the present application, and various changes, substitutions and modifications can be made without departing from the spirit and scope of the present application.

Claims

1. A semiconductor manufacturing system, characterized by comprising: The semiconductor manufacturing system comprises: an etching tool for carrying a first wafer and processing a first backside of the first wafer; and a measuring device disposed in the etching tool, wherein the measuring device comprises: a camera for taking an image of the first backside of the first wafer; and a controller for receiving the image to determine whether the first backside processed by the etching tool is over-etched and generating an over-etch signal, the controller further for calculating a plurality of differences between a color of each of a plurality of pixels of the first backside in the image and an average value, and determining whether the first backside is over-etched according to the plurality of differences, wherein the average value is calculated from colors of a plurality of normal wafers, wherein the etching tool processes the first backside using an etching solution and recycles the etching solution, and the over-etch signal is used to indicate whether the etching solution has been contaminated; wherein the semiconductor manufacturing system further comprises a host computer; wherein in response to the over-etch signal being generated, the host computer controls the etching tool to stop processing a second backside of a second wafer using the etching solution according to the over-etch signal. The second backside of the second wafer is processed by the etching tool after the first wafer is processed by the etching tool.

2. The semiconductor manufacturing system of claim 1, wherein The semiconductor manufacturing system further comprises:

3. The semiconductor manufacturing system of claim 1, wherein a wafer sensor for sensing whether the first wafer is carried by a robot arm beside the measuring device by light, wherein the wafer sensor generates a wafer sensing signal if the first wafer is carried by the robot arm; a rotation sensor for sensing whether the robot arm is rotated to an angle, wherein the robot arm carries the first wafer and rotates the first wafer to the angle such that the first backside is within a shooting range of the camera, wherein the rotation sensor generates a rotation sensing signal if the robot arm is rotated to the angle; and a relay circuit electrically connected to the controller and configured to receive the wafer sensing signal and the rotation sensing signal, wherein the relay circuit controls the controller to determine whether the first wafer is over-etched if the relay circuit receives both the wafer sensing signal and the rotation sensing signal.

4. The semiconductor manufacturing system of claim 1, wherein: the etching tool is configured to etch the first backside of the first wafer to remove a plurality of films formed on the first backside during processing of a first frontside of the first wafer. The semiconductor manufacturing system further comprises: a light emitting element configured to continuously emit light to the first wafer to reflect light to the camera.

5. The semiconductor manufacturing system of claim 1, wherein The semiconductor manufacturing system further comprises: a camera for taking an image of the first backside of the first wafer; and 6. A measuring device, characterized by a controller for receiving the image to determine whether the first backside processed by the etching tool is over-etched and generating an over-etch signal, the controller further for calculating a plurality of differences between a color of each of a plurality of pixels of the first backside in the image and an average value, and determining whether the first backside is over-etched according to the plurality of differences, wherein the average value is calculated from colors of a plurality of normal wafers, wherein the etching tool processes the first backside using an etching solution and recycles the etching solution, and the over-etch signal is used to indicate whether the etching solution has been contaminated; wherein the semiconductor manufacturing system further comprises a host computer; wherein in response to the over-etch signal being generated, the host computer controls the etching tool to stop processing a second backside of a second wafer using the etching solution according to the over-etch signal. The second backside of the second wafer is processed by the etching tool after the first wafer is processed by the etching tool. The semiconductor manufacturing system further comprises: a wafer sensor for sensing whether the first wafer is carried by a robot arm beside the measuring device by light, wherein the wafer sensor generates a wafer sensing signal if the first wafer is carried by the robot arm; a rotation sensor for sensing whether the robot arm is rotated to an angle, wherein the robot arm carries the first wafer and rotates the first wafer to the angle such that the first backside is within a shooting range of the camera, wherein the rotation sensor generates a rotation sensing signal if the robot arm is rotated to the angle; and a relay circuit electrically connected to the controller and configured to receive the wafer sensing signal and the rotation sensing signal, wherein the relay circuit controls the controller to determine whether the first wafer is over-etched if the relay circuit receives both the wafer sensing signal and the rotation sensing signal. a controller receiving the image to determine whether the first back surface processed by the etching tool is over-etched and to generate an over-etch signal, the controller further calculating a plurality of differences between a color of each of a plurality of pixels of the first back surface in the image and an average value calculated from colors of a plurality of normal wafers, and determining whether the first back surface is over-etched according to the plurality of differences, wherein the etching tool processes the first back surface using an etching solution and recovers the etching solution, and the over-etch signal is used to indicate whether the etching solution has been contaminated; wherein the measuring device controls the etching tool to stop processing a second back surface of a second wafer using the etching solution according to the over-etch signal in response to the generation of the over-etch signal.

7. A semiconductor manufacturing method, characterized by, comprising: carrying a first wafer by an etching tool and processing a first back surface of the first wafer using an etching solution; recovering the etching solution; taking an image of the first back surface of the first wafer processed by the etching tool; determining whether the first back surface processed by the etching tool is over-etched according to the image and generating an over-etch signal, wherein the over-etch signal is used to indicate whether the etching solution has been contaminated, the determining step comprising: calculating a plurality of differences between a color of each of a plurality of pixels of the first back surface in the image and an average value calculated from colors of a plurality of normal wafers, and determining whether the first back surface is over-etched according to the plurality of differences; and controlling the etching tool to stop processing a second back surface of a second wafer using the etching solution according to the over-etch signal in response to the generation of the over-etch signal, wherein the second back surface of the second wafer is processed by the etching tool after the first wafer is processed by the etching tool.

8. The semiconductor manufacturing method of claim 7, wherein processing the first back surface of the first wafer comprises: etching the first back surface by the etching tool to remove a plurality of films formed on the first back surface when processing a first front surface of the first wafer.

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