Wafer grinding device

Abstract

The utility model provides a wafer grinding device and relates to the technical field of semiconductor manufacturing, the wafer grinding device comprises a grinding assembly and a position sensor which are arranged in a grinding cavity, the grinding assembly is used for grinding a wafer located in the grinding cavity, and the position sensor is used for obtaining position information of the wafer in the grinding process in real time so as to ensure the grinding precision. In order to prevent water vapor from influencing the normal detection function of the position sensor, a first gas channel is arranged between the position sensor and the wafer. The first gas channel is provided with a first gas outlet located in the grinding cavity and outputs isolation gas through the first gas outlet to form a gas isolation layer between the position sensor and the wafer, so that water vapor is effectively prevented from making contact with the position sensor, and the problem that in the prior art, the detection function of the position sensor is affected by the water vapor is solved; the stability and the detection precision of the position sensor are improved, and the situation of false alarm or invalid detection result is avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor manufacturing, in particular to a wafer grinding device. BACKGROUND

[0002] With the feature size reduction and the increase of metal interconnection in the integrated circuit manufacturing process, the requirement for wafer surface flatness is also higher and higher. Chemical mechanical grinding (CMP) is a technology combining mechanical grinding and chemical corrosion, which is the most effective wafer planarization method at present, and is widely used in semiconductor industry manufacturing.

[0003] In the grinding process, a sensor is usually arranged in the grinding chamber to detect the position of the wafer in time, so as to ensure the grinding accuracy and the integrity of the wafer. However, a lot of water vapor is generated in the grinding process of the wafer, which will adhere to the glass of the transmitting end or the receiving end of the sensor, thereby affecting the detection function of the sensor, resulting in false alarm of the system or invalid detection result of the sensor. UTILITY MODEL CONTENT

[0004] The present application aims at the deficiencies in the prior art, and provides a wafer grinding device.

[0005] To achieve the above-mentioned purpose, the technical scheme adopted by the embodiments of the present application is as follows:

[0006] The embodiments of the present application provide a wafer grinding device, which comprises a grinding assembly and a position sensor arranged in a grinding chamber. The grinding assembly is used for grinding a wafer located in the grinding chamber. The position sensor is used for acquiring position information of the wafer in the grinding process. A first gas channel is arranged between the position sensor and the wafer. The first gas channel has a first gas outlet located in the grinding chamber. The first gas channel outputs isolation gas through the first gas outlet to form a gas isolation layer between the position sensor and the wafer.

[0007] Optionally, the wafer grinding device comprises a plurality of first gas channels arranged in a horizontal direction. The first gas outlets of the plurality of first gas channels are opposite to each other. The isolation gas in the plurality of first gas channels is discharged through the corresponding first gas outlets to jointly form the gas isolation layer.

[0008] Optionally, the wafer grinding device further comprises a second gas channel arranged in the grinding chamber. The second gas channel has a second gas inlet located in the grinding chamber and a second gas outlet located outside the grinding chamber. The isolation gas in the gas isolation layer enters the second gas channel through the second gas inlet and is discharged outside the grinding chamber through the second gas outlet.

[0009] Optionally, the second air inlet is opposite to the center of the gas isolation layer.

[0010] Optionally, the polishing assembly comprises a polishing head and a polishing pad, the polishing head is used for fixing the wafer, and the polishing pad is used for polishing the wafer.

[0011] Optionally, the polishing assembly further comprises a polishing platform, the polishing platform is used for supporting the polishing pad.

[0012] Optionally, the position sensor is an optical sensor, the optical sensor comprises a transmitting end and a receiving end, and the detection light beam emitted by the transmitting end is reflected to the receiving end through the polishing pad or the wafer.

[0013] Optionally, the first gas channel is located between the transmitting end and the wafer, and / or the first gas channel is located between the receiving end and the wafer.

[0014] Optionally, the wafer polishing device further comprises an amplifier, and the amplifier is electrically connected with the position sensor.

[0015] Optionally, the wafer polishing device further comprises a controller, and the controller is electrically connected with the position sensor.

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

[0017] The present application provides a wafer polishing device, comprising a polishing assembly and a position sensor arranged in a polishing chamber, the polishing assembly is used for polishing a wafer in the polishing chamber, and the position sensor is used for acquiring position information of the wafer in the polishing process in real time, so as to ensure the polishing precision. In order to prevent the water vapor from affecting the normal detection function of the position sensor, a first gas channel is arranged between the position sensor and the wafer. The first gas channel has a first air outlet in the polishing chamber, and the first gas channel outputs isolation gas through the first air outlet, so as to form a gas isolation layer between the position sensor and the wafer, thereby effectively preventing the water vapor from contacting the position sensor, solving the influence of the water vapor on the detection function of the position sensor in the prior art, improving the stability and detection precision of the position sensor, and avoiding false alarm or invalid detection result. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0019] Figure 1 A structure schematic diagram of a wafer polishing device provided by the embodiments of the present application.

[0020] Icon: 1 - position sensor; 11 - transmitting end; 12 - receiving end; 13 - glass; 2 - wafer; 3 - first gas passage; 4 - second gas passage; 5 - polishing pad; 6 - polishing platform; 7 - amplifier. DETAILED DESCRIPTION

[0021] In order to make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some but not all of the embodiments of the present application. The components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations.

[0022] Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. It should be noted that, in the case of no conflict, various features in the embodiments of the present application can be combined with each other, and the combined embodiments are still within the protection scope of the present application.

[0023] It should be noted that: similar reference numerals and letters represent similar items in the following drawings, therefore, once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings.

[0024] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship commonly placed when the product of the present application is used, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third" and the like are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0025] In addition, the terms "horizontal", "vertical" and the like do not mean that the components must be absolutely horizontal or vertical, but can be slightly inclined. For example, "horizontal" only means that its direction is relatively more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined.

[0026] In the description of the present application, it also needs to be explained that, unless otherwise explicitly specified and limited, the terms "set", "install", "connect", "connect" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0027] The embodiment of the present application provides a wafer grinding device, as shown in the figure, comprising a grinding assembly and a position sensor 1 arranged in the grinding chamber. The grinding assembly is used for accurate grinding of the wafer 2 located in the grinding chamber, and the position sensor 1 is used to obtain the position information of the wafer 2 in the grinding process in real time, so as to ensure the accuracy of the grinding. Figure 1

[0028] In the grinding process of the wafer 2, the grinding chamber needs to be designed to have a certain humidity to meet various needs in the grinding process. And, specific grinding liquid needs to be added in the grinding process, which not only plays a lubricating and cooling role, but also promotes the flatness and smoothness of the wafer 2 surface through chemical reaction. However, such humidity environment and addition of grinding liquid can easily produce a large amount of water vapor in the grinding process.

[0029] In order to prevent the water vapor from affecting the normal detection function of the position sensor 1, as shown in the figure, a first gas passage 3 is arranged between the position sensor 1 and the wafer 2. The first gas passage 3 has a first gas outlet in the grinding chamber, and the first gas passage 3 outputs the isolation gas through the first gas outlet to form a gas isolation layer between the position sensor 1 and the wafer 2, thereby effectively preventing the water vapor from contacting the position sensor 1, so that the position sensor 1 is in a dry environment, solving the influence of the water vapor on the detection function of the position sensor 1 in the prior art, improving the stability and detection accuracy of the position sensor 1, and avoiding false alarm or invalid detection result. Figure 1

[0030] In addition, the isolation gas can be selected from gases that have no effect on the wafer 2 and are low in cost, such as nitrogen, carbon dioxide or dry air, so as to ensure that the position sensor 1 is in a dry environment while maintaining the economy and maintainability of the wafer grinding device.

[0031] Optionally, as shown in the figure, the grinding assembly comprises a grinding head and a grinding pad 5, the grinding head is used to fix the wafer 2, and the position of the wafer 2 in the grinding process is ensured. The grinding pad 5 directly acts on the surface of the wafer 2, and the wafer 2 is processed through the CMP technology, so as to achieve the required surface flatness and smoothness. Figure 1

[0032] ​​​Specifically, the polishing head usually adopts a high-precision clamping device to ensure that the wafer 2 remains fixed and stable throughout the polishing process. The polishing pad 5 is usually made of flexible material, which can adapt to the curved surface and slight irregularities of the wafer 2, and the surface is attached with tiny abrasive particles that contact the surface of the wafer 2 during polishing and remove irregularities on the surface of the wafer 2 through mechanical friction. At the same time, the CMP technology further improves the polishing effect by adding a polishing liquid during polishing, so that a chemical reaction occurs between the polishing pad 5 and the surface of the wafer 2. Through the optimization design of the polishing assembly, the wafer polishing device of the present application realizes efficient surface flatness processing while ensuring the stability of the position of the wafer 2.

[0033] Optionally, as shown in Figure 1 The polishing assembly further comprises a polishing platform 6. The main function of the polishing platform 6 is to provide a stable support structure for carrying and supporting the polishing pad 5, so as to ensure that the polishing pad 5 remains flat during the polishing process through the stable support structure, thereby improving the uniformity and overall quality of the wafer 2 polishing.

[0034] Specifically, the polishing platform 6 is placed in the polishing chamber and is usually made of high-strength material to withstand the pressure and load applied during polishing, and its surface is finely treated to ensure good contact with the polishing pad 5. The design of the polishing platform 6 needs to take into account the size and shape of the polishing pad 5 to ensure that the polishing pad 5 can be stably fixed on the polishing platform 6 throughout the polishing process. The surface of the polishing platform 6 can be subjected to special surface treatment, such as coating or texture design, to increase the friction between the polishing pad 5 and the polishing platform 6, preventing the polishing pad 5 from moving or deforming during polishing. This design can also effectively reduce the wear of the polishing pad 5 and prolong its service life. The polishing platform 6 can also be provided with a positioning structure for accurately positioning the position of the polishing pad 5 to ensure its stability and consistency during operation.

[0035] Optionally, as shown in Figure 1 The position sensor 1 is an optical sensor, which includes an emission end 11 and a receiving end 12. The emission end 11 is responsible for emitting a detection light beam, which is reflected by the polishing pad 5 or the wafer 2 and then received by the receiving end 12. This detection process mainly judges the position and state of the wafer 2 through the reflection intensity of the light beam to ensure the accuracy and stability of the polishing process.

[0036] Specifically, when the wafer 2 is in the set position, i.e., not detached from the polishing head, the detection light beam emitted by the emission end 11 is irradiated onto the polishing pad 5 through the glass 13 (such as optical glass and / or ground glass) on its surface, and is reflected back to the receiving end 12 through the glass 13 (such as optical glass and / or ground glass) on the surface of the polishing pad 5 and the receiving end 12. In this state, the reflection intensity of the detection light beam is set as a reference intensity value.

[0037] When the wafer 2 is slipping off the polishing head, the path of the detection light beam changes. At this time, the light beam emitted by the emission end 11 directly irradiates the surface of the wafer 2 through the glass 13 (e.g. optical glass and / or frosted glass) on the surface, and is reflected back to the receiving end 12 through the glass 13 (e.g. optical glass and / or frosted glass) on the surface of the wafer 2 and the receiving end 12. In this process, due to the different surface characteristics of the wafer 2, the intensity of the light beam reflected back to the receiving end 12 will be significantly higher than the reference intensity value. This intensity change can be accurately detected, so as to determine the position state of the wafer 2, and then to adjust and control the polishing process in real time.

[0038] Therefore, the optical sensor can detect and feedback the state of the wafer 2 in the polishing process in real time, so as to avoid the situation that the wafer 2 slips off or slips out. The intensity change of the detection light beam provides reliable data support for the automatic adjustment of the polishing process, and ensures the accurate control of the polishing head and the polishing pad 5.

[0039] In order to prevent water vapor from being formed on the surface of the glass 13 (e.g. optical glass and / or frosted glass) during the polishing process, which affects the normal detection function of the optical sensor, optionally, a first gas channel 3 is arranged between the emission end 11 and the wafer 2, and / or between the receiving end 12 and the wafer 2, so as to form a gas isolation layer between the optical sensor and the wafer 2, thereby preventing the condensation and adhesion of water vapor, and ensuring the normal work of the optical sensor.

[0040] Specifically, as shown in Figure 1 The first gas channel 3 can be arranged between the emission end 11 and the wafer 2 or between the receiving end 12 and the wafer 2, or can be arranged at both positions. Through the gas outlet of the first gas channel 3, the isolation gas can be continuously delivered to the surface of the glass 13 (e.g. optical glass and / or frosted glass) of the optical sensor, so as to form a gas isolation layer. The continuous delivery of the isolation gas and the formation of the gas isolation layer can effectively prevent the condensation and adhesion of water vapor on the surface, so as to ensure that the channel for emitting and receiving the detection light beam of the optical sensor is always clean and transparent, thereby avoiding the situation of false alarm or invalid detection result. In addition, the existence of the gas isolation layer can also reduce the interference of other environmental impurities on the optical sensor, and improve the detection accuracy and reliability of the optical sensor.

[0041] Optionally, the wafer polishing device comprises a plurality of first gas channels 3 arranged in the horizontal direction, the first gas outlets of the plurality of first gas channels 3 are opposite to each other, and the isolation gas in the plurality of first gas channels 3 is discharged through the corresponding first gas outlets to form a gas isolation layer.

[0042] Specifically, as shown in Figure 1As shown, each first gas channel 3 has a first air inlet located outside the grinding chamber and a first air outlet located inside the grinding chamber. Each first air inlet is connected to a gas source, or multiple air inlets are connected to the same gas source. When the gas source supplies isolation gas, the isolation gas enters the corresponding first gas channel 3 through the multiple first air inlets, flows through the corresponding first gas channel 3 to the corresponding first air outlet, and is finally discharged into the grinding chamber through the corresponding first air outlet. Since the multiple first air outlets are opposite each other, the discharged isolation gas gathers between the optical sensor and the wafer 2, forming a uniform and continuous gas isolation layer.

[0043] This arrangement not only ensures the stability and consistency of the gas isolation layer, but also more effectively prevents water vapor and other impurities from condensing and adhering to the surface of the glass 13 (e.g., smooth glass and / or frosted glass) of the optical sensor. Furthermore, the multiple first gas channels 3 arranged horizontally can cover the entire detection area of ​​the optical sensor, further improving its reliability and detection accuracy.

[0044] Optionally, such as Figure 1 As shown, the wafer polishing apparatus also includes a second gas channel 4 disposed in the polishing chamber. The second gas channel 4 has a second air inlet located inside the polishing chamber and a second air outlet located outside the polishing chamber. The isolation gas in the gas isolation layer enters the second gas channel 4 through the second air inlet and is discharged outside the polishing chamber through the second air outlet, thereby preventing the isolation gas from accumulating in the polishing chamber and affecting the normal operation and polishing effect of the wafer polishing apparatus.

[0045] Specifically, after the isolation gas in the gas isolation layer is formed and stabilized under the action of the first gas channel 3, the excess isolation gas enters the second gas channel 4 through the second inlet. The second gas channel 4, through a reasonable pipe design, guides the incoming isolation gas to the outside of the grinding chamber. Through the second outlet located outside the grinding chamber, this excess isolation gas is effectively discharged from the grinding chamber, maintaining gas balance and a suitable working environment within the grinding chamber.

[0046] This design not only prevents gas from accumulating in the grinding chamber from the gas isolation layer, but also ensures the ventilation and exhaust effect of the entire wafer grinding device, which helps maintain a stable environment in the grinding chamber and further improves the working efficiency and accuracy of the grinding device.

[0047] Optionally, such as Figure 1 As shown, the second air inlet corresponds to the center of the gas isolation layer. Excess isolation gas enters the second gas channel 4 through the second air inlet located at the center and is discharged outside the grinding chamber through the second air outlet, thereby maintaining a stable gas environment.

[0048] From the foregoing, by setting multiple first gas outlets opposite to each other, the isolation gas can flow uniformly from all around to the central area, forming a stable gas barrier to prevent water vapor and impurities from interfering with the optical sensor. At the same time, the second gas inlet of the second gas channel 4 is arranged at a position corresponding to the center position of the gas isolation layer. Through this design, the excess isolation gas can be effectively guided and discharged from the central area of the gas isolation layer, effectively avoiding the accumulation of isolation gas in the chamber, reducing the unevenness of gas flow and the possible gas retention problem, ensuring that the gas environment in the grinding chamber remains stable and clean at all times, providing a suitable working environment.

[0049] Optionally, as shown in Figure 1 The wafer grinding device also includes an amplifier 7, which is designed to improve the processing capability of the position sensor 1 detection signal. The amplifier 7 is connected to the position sensor 1 through an electrical connection, responsible for amplifying the signal received by the position sensor 1, and displaying the intensity value of the signal, making the detection process more intuitive and efficient, helping to accurately determine the position of the wafer 2 during grinding, thereby optimizing the grinding quality and operation precision of the device.

[0050] Specifically, the amplifier 7 is connected to the optical sensor through a cable and can receive the detection signal from the optical sensor in real time. The core function of the amplifier 7 is to amplify the signal transmitted by the optical sensor, which can enhance the weak signal to a readable intensity range, making the detection data clearer and more reliable. Through this signal amplification, the sensitivity and accuracy of the optical sensor to the position change of the wafer 2 can be improved.

[0051] In addition, the amplifier 7 is also equipped with display function, can amplify the signal intensity value in the form of digital real-time display on the display screen. Users can intuitively observe the position change of the wafer 2 through the display screen, so as to adjust the grinding parameters or carry out necessary operation intervention in time. This visual display mode improves the convenience of operation and the accuracy of judgment.

[0052] Optionally, the wafer grinding device also includes a controller and an alarm, the controller is connected to the position sensor 1 and the alarm through an electrical connection, in order to realize the automatic monitoring and abnormal detection of the grinding process. The controller adjusts the grinding parameters in real time according to the signal transmitted by the position sensor 1, and triggers the alarm when an abnormal situation is found, in order to protect the wafer grinding device and ensure the grinding quality.

[0053] Specifically, the electrical connection of the controller with the position sensor 1 enables the controller to receive position signals from the position sensor 1 in real time. The controller processes and analyzes the received signals and automatically adjusts the working parameters of the polishing device, such as polishing pressure, speed, etc., to ensure that the wafer 2 is polished within the preset position range. The controller also has data storage and processing capabilities and can record various data during the polishing process to provide a reference for subsequent analysis and adjustment.

[0054] The electrical connection of the controller with the alarm allows the controller to trigger the alarm immediately when an abnormal situation is detected. The alarm can emit sound and light signals to prompt the operator to check and handle immediately. Abnormal situations may include the position sensor 1 signal exceeding the set range, the polishing process failing or other abnormal states. Through such an automated alarm system, potential problems can be quickly responded to, avoiding damage to the wafer 2 and the equipment.

[0055] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Those skilled in the art can make various modifications and changes to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A wafer polishing apparatus characterized by comprising: The wafer polishing device comprises a polishing assembly and a position sensor (1) arranged in a polishing chamber, the polishing assembly is used for polishing a wafer (2) in the polishing chamber, the position sensor (1) is used for acquiring position information of the wafer (2) in the polishing process, a first gas channel (3) is arranged between the position sensor (1) and the wafer (2), the first gas channel (3) has a first gas outlet in the polishing chamber, and the first gas channel (3) outputs isolation gas through the first gas outlet to form a gas isolation layer between the position sensor (1) and the wafer (2); The wafer polishing device comprises a plurality of first gas channels (3) arranged in a horizontal direction, the first gas outlets of the plurality of first gas channels (3) are opposite to each other, and the isolation gas in the plurality of first gas channels (3) is discharged through the corresponding first gas outlets to form the gas isolation layer together. The wafer polishing device further comprises a second gas channel (4) arranged in the polishing chamber, the second gas channel (4) has a second gas inlet in the polishing chamber and a second gas outlet outside the polishing chamber, and the isolation gas in the gas isolation layer enters the second gas channel (4) through the second gas inlet and is discharged outside the polishing chamber through the second gas outlet.

2. The wafer polishing apparatus according to claim 1, wherein The second gas inlet is opposite to the center position of the gas isolation layer.

3. The wafer polishing apparatus of claim 1, wherein The polishing assembly comprises a polishing head and a polishing pad (5), the polishing head is used for fixing the wafer (2), and the polishing pad (5) is used for polishing the wafer (2).

4. The wafer polishing apparatus according to claim 3, wherein The polishing assembly further comprises a polishing platform (6) for supporting the polishing pad (5).

5. The wafer polishing apparatus of claim 3, wherein The position sensor (1) is an optical sensor, the optical sensor comprises an emission end (11) and a receiving end (12), and a detection light beam emitted by the emission end (11) is reflected to the receiving end (12) through the polishing pad (5) or the wafer (2).

6. The wafer polishing apparatus of claim 5, wherein The first gas channel (3) is located between the emission end (11) and the wafer (2), and / or the first gas channel (3) is located between the receiving end (12) and the wafer (2).

7. The wafer polishing apparatus of claim 1, wherein The wafer polishing device further comprises an amplifier (7) electrically connected with the position sensor (1).

8. The wafer polishing apparatus of claim 1, wherein The wafer polishing device further comprises a controller electrically connected with the position sensor (1).

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