Wafer monitoring mechanism and CMP machine table

Abstract

The utility model provides a wafer monitoring mechanism and a CMP machine table. The wafer monitoring mechanism is used for a CMP machine table and comprises at least one laser sensor arranged in a grinding disc of the CMP machine table, and the laser sensor is used for emitting laser to a wafer in a grinding head of the CMP machine table and receiving the laser reflected by the wafer; the projection of the wafer on the grinding disc completely covers the laser sensors at certain intervals, and the center of one laser sensor coincides with the center of the wafer. The laser sensor is arranged in the grinding disc of the CMP machine table, whether the wafer is in place or not can be monitored in real time, and safety and reliability in the grinding process are improved; therefore, equipment damage caused by the fact that the wafer is not in place is avoided, maintenance cost and part replacement cost caused by equipment damage are reduced, downtime caused by equipment damage and maintenance is shortened, operation time of a machine is prolonged, and overall production efficiency is improved.

Description

Technical Field

[0001] This utility model relates to the field of semiconductor manufacturing, specifically to a wafer monitoring mechanism and a CMP machine. Background Technology

[0002] In the semiconductor manufacturing industry, CMP (Chemical Mechanical Polishing) machines are indispensable key equipment in the wafer processing, mainly used to achieve wafer surface planarization. The CMP process removes excess material from the wafer surface through physical and chemical interactions between the polishing pad and the wafer to achieve the required surface flatness.

[0003] However, during CMP polishing, the lack of real-time monitoring devices for the wafer's on-site status means that if wafer fragmentation occurs during polishing, the CMP machine cannot immediately detect this anomaly and cannot stop polishing in time. In this situation, the polishing process will continue until serious consequences occur, including but not limited to damage to the polishing pad, scratches on the polishing disc, and rupture of the air film in the polishing head. Furthermore, the air lines may experience pressure instability due to foreign objects entering during polishing, eventually triggering an alarm, at which point the CMP machine will be forced to stop. These damaged components are not only expensive but also complex to replace and repair, directly increasing the operating cost of the CMP machine. Simultaneously, the need for machine downtime for repairs inevitably affects the overall efficiency and capacity of the production line, causing unnecessary downtime and reducing the machine's uptime. Utility Model Content

[0004] In view of the problems that occur in the grinding process of existing CMP machines, this application provides a wafer monitoring mechanism and a CMP machine. This wafer monitoring mechanism, by installing a laser sensor inside the grinding disc of the CMP machine, can monitor the wafer's position in real time, improving safety and reliability during the grinding process; preventing equipment damage due to wafer misalignment, reducing maintenance and replacement costs caused by equipment damage, minimizing downtime due to equipment damage and maintenance, increasing machine uptime, and improving overall production efficiency.

[0005] One embodiment of this application provides a wafer monitoring mechanism for a CMP machine, including at least one laser sensor disposed in the grinding disk of the CMP machine. The laser sensor is used to emit laser light onto a wafer in the grinding head of the CMP machine and to receive laser light reflected by the wafer.

[0006] At regular intervals, the projection of the wafer onto the grinding disk completely covers the laser sensor, and the center of one of the laser emitters coincides with the center of the wafer.

[0007] In one implementation, at least two laser sensors are provided, wherein the centers of the two laser sensors are located on the same radius of the grinding disk.

[0008] In one implementation, at least three laser sensors are provided, wherein the centers of the three laser sensors are located on the same radius of the grinding disc.

[0009] In one implementation, three laser sensors are provided, with the centers of the three laser sensors located on the same radius of the grinding disc.

[0010] In one implementation, five laser sensors are provided, arranged in a cross shape, with the centers of three of the laser sensors located on the same radius of the grinding disc.

[0011] In one embodiment, the grinding disc has at least one opening, and the laser sensor is disposed within the opening;

[0012] The polishing pad supported on the grinding disc is provided with a through-hole, the position of which corresponds to the position of the opening.

[0013] As one implementation, a controller is also included, and the laser sensor is connected to the controller.

[0014] As one implementation, the system also includes a controller and a signal amplifier, with the laser sensor connected to the signal amplifier and the signal amplifier connected to the controller.

[0015] As one implementation, an alarm is also included, which is connected to the controller.

[0016] Another embodiment of this application provides a CMP machine that includes the wafer monitoring mechanism described above.

[0017] As described above, the wafer monitoring mechanism and CMP equipment of this application have the following beneficial effects:

[0018] The wafer monitoring mechanism of this application enables real-time monitoring of the wafer's position by installing a laser sensor within the grinding pad of the CMP machine, thereby enhancing the safety and reliability of the grinding process. It promptly detects wafer misplacement, preventing damage to the grinding pad and polishing mat due to wafer loss and protecting critical components of the CMP machine. This reduces equipment damage caused by wafer misplacement, lowering maintenance and replacement costs. By promptly stopping unnecessary grinding processes, it reduces downtime due to equipment damage and maintenance, increasing machine uptime. Ultimately, reduced downtime and maintenance costs improve overall production efficiency and contribute to increased production capacity. Attached Figure Description

[0019] Figure 1 The diagram shown is a top view of the first type of wafer monitoring mechanism according to Embodiment 1 of this utility model.

[0020] Figure 2 The diagram shown is a top view of the second type of wafer monitoring mechanism according to Embodiment 1 of this utility model.

[0021] Figure 3 The diagram shown is a top view of the third type of wafer monitoring mechanism according to Embodiment 1 of this utility model.

[0022] Figure 4 The diagram shown is a top view of the fourth wafer monitoring mechanism according to Embodiment 1 of this utility model.

[0023] Figure 5 The diagram shown is a top view of the fifth type of wafer monitoring mechanism according to Embodiment 1 of this utility model.

[0024] Figure 6 The diagram shown is a structural schematic of the CMP machine according to Embodiment 2 of this utility model.

[0025] Component designation explanation

[0026] 100, Grinding disc; 110, Laser sensor; 200, Grinding head; 300, Wafer; 400, Polishing pad. Detailed Implementation

[0027] The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model.

[0028] Please see Figures 1 to 6 It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of this utility model. Therefore, the illustrations only show the components related to this utility model and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0029] In the semiconductor manufacturing industry, wafer fabrication is a highly precise and complex process, in which chemical mechanical polishing (CMP) technology plays a crucial role. CMP equipment, as the core equipment in the wafer fabrication process, is mainly used to achieve wafer surface planarization to ensure the smooth progress of subsequent process steps and the performance quality of the final product.

[0030] CMP (Chemical Motion Polishing) precisely removes excess material from the wafer surface through physical and chemical interactions between the polishing pad and the wafer, achieving the desired surface smoothness. This process is crucial for improving the integration and performance of semiconductor devices. However, a significant technical challenge in CMP polishing is the lack of real-time monitoring devices for the wafer's in-situ condition.

[0031] Currently, CMP (Chemical Mechanical Polishing) machines cannot detect changes in wafer condition in real time during the polishing process. In particular, when wafers break down due to various reasons (such as material defects or improper polishing parameters), the machine cannot immediately detect this anomaly and take appropriate stop measures. This allows the polishing process to continue until serious consequences occur, including but not limited to damage to the polishing pad, scratches on the polishing disc, and rupture of the air film on the polishing head. These damaged components are not only expensive, but their replacement and repair are also complex, significantly increasing the operating costs of CMP machines.

[0032] Furthermore, foreign objects may be generated during CMP polishing, which can enter the gas lines, causing pressure instability and ultimately triggering an alarm. Only then will the CMP machine be forced to stop operating. However, this shutdown method is not based on real-time monitoring of the wafer's condition, but rather relies on the occurrence of subsequent faults and the response of the alarm system, thus exhibiting significant lag and uncertainty.

[0033] In summary, the shortcomings of existing CMP machines in real-time monitoring of their status upon entering the facility not only increase the operating costs and maintenance complexity of the machines, but also seriously affect the overall efficiency and capacity of the production line.

[0034] To address the above deficiencies, this application provides a wafer inspection mechanism and a CMP machine. The following embodiments will provide a detailed description.

[0035] Example 1

[0036] This embodiment provides a wafer monitoring mechanism for use in a CMP machine, such as... Figures 1 to 5As shown, the wafer monitoring mechanism includes at least one laser sensor 110. The laser sensor 110 is disposed within the polishing disk 100 of the CMP machine and is used to emit laser signals to the wafer 300 within the polishing head of the CMP machine, and to receive the laser signals reflected by the wafer 300. At regular intervals, the projection of the wafer 300 onto the polishing disk 100 completely covers the laser sensor 110, and the center of one of the laser sensors 110 coincides with the center of the wafer 300 (or, in other words, the line connecting the center of the laser sensor 110 and the center of the wafer 300 is perpendicular to the polishing disk 100). The polishing disk 100 rotates in the same direction as the polishing head, but the rotation speed of the polishing disk 100 is different from that of the polishing head. The "regular intervals" refer to the time it takes for the laser sensor 110 to rotate 360 ​​degrees from below the wafer 300 and return to below the wafer 300, which is the time it takes for the polishing disk 100 to complete one revolution. In this way, the laser sensor 110 can monitor the presence of the wafer 300 in real time, enhancing the safety and reliability of the grinding process; it can promptly detect when the wafer is not in place, preventing damage to the grinding disc 100 and polishing pad 400 due to wafer loss, thus protecting critical components of the CMP machine; it reduces equipment damage caused by the wafer 300 not being in place, lowering maintenance and replacement costs; by promptly stopping unnecessary grinding processes, it reduces downtime caused by equipment damage and maintenance, increasing machine uptime; and due to reduced downtime and maintenance costs, overall production efficiency is improved, contributing to increased production capacity.

[0037] In optional embodiments, such as Figure 1 As shown, a laser sensor 110 is provided inside the grinding disk 100. The center of the projection of the wafer 300 on the grinding disk 100 coincides with the center of the laser sensor 110, thus enabling the monitoring of whether the wafer 300 is in place.

[0038] In optional embodiments, such as Figure 2 and Figure 3 As shown, two laser sensors 110 are disposed inside the grinding disk 100, and the center of one of the laser sensors 110 coincides with the center of the projection of the wafer 300 onto the grinding disk 100. Figure 2 Another laser sensor 110 is located outside the first laser sensor 110. Figure 3 Another laser sensor 110 is disposed inside the first laser sensor 110. Figure 2 and Figure 3 The centers of the two laser sensors 110 are located on the same radius of the grinding disk 100, which further improves the accuracy of the wafer monitoring mechanism in monitoring whether the wafer 300 is in place.

[0039] In optional embodiments, such as Figure 4As shown, three laser sensors 110 are provided inside the polishing pad 100. The center of the first laser sensor coincides with the center of the projection of the wafer 300 onto the polishing pad 100. The second laser sensor is located outside the first laser sensor, and the third laser sensor is located inside the first laser sensor. The centers of the three laser sensors 110 are located on the same radius of the polishing pad 100. This further increases the range of laser signals emitted by the laser sensors 110 to the wafer 300, further improves the accuracy of monitoring whether the wafer 300 is in place, and can also improve the utilization rate of the polishing pad 400.

[0040] In optional embodiments, such as Figure 5 As shown, five laser sensors 110 are provided inside the grinding disk 100. The center of the first laser sensor coincides with the center of the projection of the wafer 300 onto the grinding disk 100. The second laser sensor is located outside the first laser sensor, and the third laser sensor is located inside the first laser sensor. The centers of the three laser sensors 110 are located on the same radius of the grinding disk 100. The centers of the first, fourth, and fifth laser sensors are located on the same straight line, which is perpendicular to the straight line containing the centers of the first, second, and third laser sensors. This further increases the range of laser signals emitted by the laser sensors 110 to the wafer 300, and further improves the accuracy of monitoring whether the wafer 300 is in place.

[0041] In an optional embodiment, the polishing pad 100 has openings (not shown), and laser sensors 110 are disposed within the openings. The number of openings is the same as the number of laser sensors 110. Simultaneously, the polishing pad 400, supported on the polishing pad 100, has through-holes, the number and position of which correspond one-to-one with the openings and positions on the polishing pad 100. The laser signals emitted by the laser sensors 110 pass through the openings and through-holes to the surface of the wafer 300 near the polishing pad 400.

[0042] In optional embodiments, such as Figure 1 As shown, the wafer monitoring mechanism also includes a controller. The laser sensor 110 is connected to the controller. The laser sensor 110 transmits the laser signal reflected by the wafer 300 to the controller. The controller determines whether the wafer 300 is in place based on the intensity of the laser signal. If the wafer 300 is in place, the CMP machine continues to work. If the wafer 300 is not in place, the CMP machine is stopped.

[0043] In optional embodiments, such as Figure 1As shown, the wafer monitoring mechanism also includes a signal amplifier. The input of the signal amplifier is connected to the laser sensor 110, and the output of the signal amplifier is connected to the controller. During the grinding process, when the grinding head carrying the wafer 300 passes the laser sensor 110, the laser signal emitted by the laser sensor 110 is reflected back by the wafer 300. The signal amplifier amplifies the received signal, and an appropriate threshold is set within the signal amplifier. If the amplified signal is higher than the threshold, it indicates that the wafer 300 is in place; if the amplified signal is lower than the threshold, it indicates that the wafer 300 is not in place. The signal amplifier transmits the judgment result to the controller, and the controller sends a signal to the CMP machine to determine whether to continue operation based on the judgment result.

[0044] In optional embodiments, such as Figure 1 As shown, the wafer monitoring mechanism also includes an alarm, which is connected to the controller. If the controller receives a judgment result indicating that wafer 300 is not in place, the controller sends an alarm signal to the alarm. After the alarm sounds, the operator stops the CMP machine. The alarm can be an audible alarm and / or an indicator light alarm, etc.

[0045] Understandable. Figures 2 to 5 Signal amplifiers, controllers, and alarms can also be installed in the system. Figures 2 to 5 Not shown in the image.

[0046] Example 2

[0047] This embodiment provides a CMP machine, such as Figure 6 As shown, the CMP machine includes a grinding disk 100, a polishing pad 400, a grinding head 200, and a wafer monitoring mechanism. The wafer monitoring mechanism can be the one provided in Embodiment 1. The polishing pad 400 is disposed on the upper surface of the grinding disk 100, and a first rotation mechanism is disposed on the lower surface of the grinding disk 100, which drives the grinding disk 100 to rotate. The grinding head 200 is disposed above the grinding disk 100, and a wafer 300 is disposed on the surface of the grinding head 200 near the grinding disk 100. A second rotation mechanism is disposed on the surface of the grinding head 200 away from the grinding disk 100, which drives the grinding head 200 to rotate. The rotation speed of the first rotation mechanism is different from the rotation speed of the second rotation mechanism. By installing a wafer monitoring mechanism on the CMP machine, the presence of wafer 300 can be monitored in real time, enhancing the safety and reliability of the CMP grinding process; preventing damage to the grinding pad 100 and polishing pad 400 due to wafer 300 absence, thus protecting critical components of the CMP machine; reducing equipment damage caused by wafer misplacement, lowering maintenance and replacement costs; reducing downtime due to equipment damage and maintenance by promptly stopping unnecessary grinding processes, thereby increasing CMP machine uptime; and improving overall production efficiency due to reduced downtime and maintenance costs, thus contributing to increased production capacity.

[0048] The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit the scope of this utility model. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.

Claims

1. A wafer monitoring mechanism for a CMP machine, characterized in that, Includes at least one laser sensor disposed within the grinding disc of the CMP machine, the laser sensor being used to emit laser light onto the wafer within the grinding head of the CMP machine and to receive laser light reflected from the wafer; At regular intervals, the projection of the wafer onto the grinding disk completely covers the laser sensor, and the center of one of the laser sensors coincides with the center of the wafer.

2. The wafer monitoring mechanism according to claim 1, characterized in that, At least two laser sensors are provided, wherein the centers of the two laser sensors are located on the same radius of the grinding disk.

3. The wafer monitoring mechanism according to claim 1, characterized in that, At least three laser sensors are provided, wherein the centers of the three laser sensors are located on the same radius of the grinding disc.

4. The wafer monitoring mechanism according to claim 1, characterized in that, Three laser sensors are provided, with the centers of the three laser sensors located on the same radius of the grinding disc.

5. The wafer monitoring mechanism according to claim 1, characterized in that, Five laser sensors are provided, arranged in a cross shape, with the centers of three of the laser sensors located on the same radius of the grinding disc.

6. The wafer monitoring mechanism according to claim 1, characterized in that, The grinding disc has at least one opening, and the laser sensor is disposed within the opening; The polishing pad supported on the grinding disc has a through-hole, the position of which is opposite to the position of the opening. answer.

7. The wafer monitoring mechanism according to claim 1, characterized in that, It also includes a controller, to which the laser sensor is connected.

8. The wafer monitoring mechanism according to claim 1, characterized in that, It also includes a controller and a signal amplifier, with the laser sensor connected to the signal amplifier and the signal amplifier connected to the controller.

9. The wafer monitoring mechanism according to claim 7 or 8, characterized in that, It also includes an alarm, which is connected to the controller.

10. A CMP machine, characterized in that, Includes the wafer monitoring mechanism as described in any one of claims 1 to 9.

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