Grinding device

Abstract

The utility model provides a grinding device. The grinding device comprises a grinding disc, a grinding head, a temperature sensor and a laser generator, wherein the grinding head, the temperature sensor and the laser generator are matched with the grinding disc. The temperature sensor is located on one side of the working face of the grinding disc and is configured to obtain a temperature signal of the grinding disc and output the temperature signal. The laser generator is located on one side of the working face of the grinding disc and coupled with the temperature sensor, and the laser generator is configured to emit a heating signal to the grinding disc according to the temperature signal. Therefore, the laser generator can heat the grinding disc according to the temperature signal of the temperature sensor, so that the temperature of the grinding disc is controlled within a specified range, namely the grinding temperature is controlled within the specified range.

Description

Technical Field

[0001] This application generally relates to the field of semiconductors, and more specifically, to a grinding device. Background Art

[0002] In semiconductor manufacturing process technology, surface planarization is an important technology for processing high-density lithography. Only a flat surface without height differences can avoid exposure scattering and achieve precise pattern transfer (PT). The main planarization technologies include Spin On Glass (SOG) and Chemical Mechanical Polish (CMP), etc. However, after the semiconductor manufacturing process technology enters the nanometer era, the Spin On Glass method can no longer meet the required flatness. Therefore, the Chemical Mechanical Polish method has become a technology that can achieve "Global Planarization (GP)" for very large scale integrated circuits, even ultra-large scale integrated circuits and gigascale integrated circuits, and it is an important process in semiconductor manufacturing technology.

[0003] The Chemical Mechanical Polish method is completed by dedicated chemical mechanical grinding equipment. A chemical mechanical grinding machine mainly includes: a workbench, a grinding pad laid on the workbench, a pipe fitting for delivering polishing liquid to the grinding pad, a liquid pump for pumping the polishing liquid into the pipe fitting, and an adjusting brush and a series of other components. Usually, heat will be generated during the chemical mechanical grinding process due to chemical and mechanical actions, and as the temperature rises, it will affect the grinding rate and grinding uniformity.

[0004] However, traditional machines do not have a temperature control system, so they cannot well solve the temperature control problem during chemical mechanical grinding. Summary of the Utility Model

[0005] The purpose of this application is to provide a grinding device, aiming to achieve the control of the temperature of the grinding disc.

[0006] This application provides a grinding device, including:

[0007] A grinding disc and a grinding head that cooperates with the grinding disc;

[0008] A temperature sensor, located on one side of the working surface of the grinding disc, and configured to obtain the temperature signal of the grinding disc and output the temperature signal;

[0009] A laser generator, located on the working surface side of the grinding disc, and coupled to the temperature sensor. The laser generator is configured to heat the grinding disc according to the temperature signal.

[0010] In some embodiments, the polishing pad rotates about the center of the polishing pad in a first direction, the polishing head has a first side and a second side, and the direction from the first side to the second side of the polishing head is consistent with the first direction;

[0011] The distance from the temperature sensor to the second side is less than the distance from the temperature sensor to the first side;

[0012] The distance from the laser generator to the first side is less than the distance from the laser generator to the second side.

[0013] In some embodiments, the polishing head is located on the working surface side of the polishing pad, and the polishing head is fixed relative to the center of the polishing pad;

[0014] The laser generator is fixedly arranged relative to the polishing head, and the temperature sensor is fixedly arranged relative to the polishing head.

[0015] In some embodiments, the working surface of the polishing pad includes a plurality of temperature control regions;

[0016] The laser generator includes a plurality of laser generating units, one of the laser generating units corresponds to controlling the temperature of one of the temperature control regions, and the temperatures of at least two of the temperature control regions are different.

[0017] In some embodiments, the plurality of laser generating units are arranged adjacent to each other in a straight line, and the trajectory formed by the movement of one of the laser generating units relative to the polishing pad is the corresponding temperature control region.

[0018] In some embodiments, during the movement of the polishing pad, the orthographic projection of the polishing head on the polishing pad is within the orthographic projection range of the plurality of temperature control regions.

[0019] In some embodiments, the dimension of the laser generator along the extending direction of the straight line is greater than or equal to the diameter of the polishing head.

[0020] In some embodiments, the plurality of laser generating units are arranged adjacent to each other in the radial direction of the polishing pad.

[0021] In some embodiments, the diameter of the polishing head is less than the radius of the polishing pad, and the minimum distance between the edge of the polishing head and the center of the polishing pad is greater than 0.

[0022] In some embodiments, the temperature sensor includes a plurality of temperature sensing units, the plurality of temperature sensing units are coupled to the plurality of laser generating units in a one-to-one correspondence, and one of the temperature sensing units is configured to feedback the temperature of one of the temperature control regions to one of the laser generating units.

[0023] The present application provides a grinding device, which includes a grinding disc, a grinding head, a temperature sensor and a laser generator that cooperate with the grinding disc. The temperature sensor is located on one side of the working surface of the grinding disc and is configured to acquire the temperature signal of the grinding disc and output the temperature signal. The laser generator is located on the side of the working surface of the grinding disc and is coupled to the temperature sensor. The laser generator is configured to emit a heating signal to the grinding disc according to the temperature signal. Therefore, the laser generator can heat the grinding disc according to the temperature signal of the temperature sensor, so as to control the temperature of the grinding disc within a specified range, that is, the temperature of grinding is controlled within a specified range. Description of the Drawings

[0024] Combined with the following drawings, through a detailed description of the specific embodiments of the present application, the technical solutions and other beneficial effects of the present application will be obvious.

[0025] Figure 1 is a schematic side view structure of the grinding device provided by some embodiments of the present application;

[0026] Figure 2 is a schematic top view structure of the grinding disc and the grinding head provided by some embodiments of the present application;

[0027] Figure 3 is a schematic structure diagram of the grinding disc, the grinding head, the laser generator and the temperature sensor provided by some embodiments of the present application;

[0028] Figure 4 is a schematic structure diagram of the grinding disc, the grinding head, the laser generator and the temperature sensor provided by some embodiments of the present application. Detailed Embodiments

[0029] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts shall fall within the protection scope of the present application.

[0030] It should be understood that although the terms first, second, etc. may be used herein to describe various components, these components should not be limited by these terms. These terms are used to distinguish one component from another. For example, the first component may be referred to as the second component, and similarly, the second component may be referred to as the first component, without departing from the scope of the present application.

[0031] It should be understood that when a component is referred to as being "on" another component or "connected" to another component, it can be directly on the other component or connected to the other component, or there can also be intervening components. Other words used to describe the relationship between components should be interpreted in a similar manner.

[0032] As used herein, the term "layer" refers to a portion of a material that includes a region having a thickness. The layer can extend over the entire underlying or overlying structure, or can have a scope that is less than the scope of the underlying or overlying structure. Additionally, the layer can be a region of a uniform or non-uniform continuous structure having a thickness less than the thickness of the continuous structure. For example, the layer can be located between the top and bottom surfaces of the continuous structure or between any set of horizontal planes at the top and bottom surfaces. The layer can extend horizontally, vertically, and / or along a tapered surface. The substrate can be a layer, which can include one or more layers, and / or can have one or more layers on, above, and / or below it. The layer can include multiple layers. For example, an interconnect layer can include one or more second conductive layers and contact layers and one or more dielectric layers.

[0033] It should be noted that the diagrams provided in the embodiments of the present application only illustrate the basic concept of the present application in a schematic manner. Although only the components related to the present application are shown in the diagrams and are not drawn according to the number, shape, and size of the components in actual implementation, the type, quantity, and ratio of the components in actual implementation can be arbitrarily changed, and the component layout type may also be more complex.

[0034] Please refer to Figure 1 , Figure 1 which is a schematic side view structure diagram of a grinding device provided by some embodiments of the present application.

[0035] The grinding device 100 includes a grinding disk 10 and a grinding head 20, a temperature sensor 30, and a laser generator 40 that cooperate with the grinding disk 10. The temperature sensor 30 is located on one side of the working surface 11 of the grinding disk 10 and is configured to acquire the temperature signal of the grinding disk 10 and output the temperature signal. The laser generator 40 is located on the working surface 11 side of the grinding disk 10 and is coupled to the temperature sensor 30. The laser generator 40 is configured to emit a heating signal to the grinding disk 10 according to the temperature signal. Therefore, the laser generator 40 can heat the grinding disk 10 according to the temperature signal of the temperature sensor 30, so as to control the temperature of the grinding disk 10 within a specified range, that is, the grinding temperature can be controlled within a specified range.

[0036] The working surface 11 of the polishing pad 10 refers to one side surface for polishing a wafer (or a workpiece to be polished). The polishing pad 10 may include a workbench and a polishing pad located on the surface of the workbench, and the polishing pad is used for polishing the wafer. The polishing pad may have a certain surface roughness and surface grooving depth. The certain surface roughness is used for polishing, and the certain surface grooving depth is used for the polishing pad to store and transport the polishing liquid 60.

[0037] It should be noted that the wafer in this application may refer to a semiconductor device, such as a memory. The memory may include a select-only memory, a phase change memory, etc., and this application is not limited thereto.

[0038] The polishing pad 10 may be circular. Then, the center of the polishing pad 10 is the center of the circle of the polishing pad 10. When the polishing pad 10 is in the working state, it rotates clockwise or counterclockwise around the center, so as to polish the wafer.

[0039] The polishing head 20 may be located on one side of the working surface 11 of the polishing pad 10, and the polishing head 20 is fixed relative to the center of the polishing pad 10. The polishing head 20 can hold the wafer 50 and press the surface to be polished of the wafer 50 against the working surface 11 of the polishing pad 10 with a certain pressure. That is to say, the positions of the polishing head 20 and the wafer 50 are fixed, while the polishing pad 10 rotates.

[0040] Please refer to Figure 2 , Figure 2 which is a schematic top view structure diagram of the polishing pad and the polishing head provided by some embodiments of this application.

[0041] The bottom of the polishing head 20 opposite to the polishing pad 10 may be circular. The diameter of this bottom is smaller than the radius of the polishing pad 10, and the minimum distance between the edge of the polishing head 20 and the center of the polishing pad 10 is greater than 0. That is to say, the polishing head 20 does not cover the center O of the polishing pad 10. In this way, during the process of the polishing pad 10 polishing the wafer 50 by rotation, most of the working surface 11 of the polishing pad 10 can contact the wafer 50, which is beneficial to increasing the service life of the polishing pad, reducing the replacement times of the polishing pad, and reducing costs.

[0042] The polishing device 100 may further include a polishing pad truing device (not shown). The polishing pad truing device includes a rotating shaft and a truing disk mounted on the rotating shaft. The truing disk is used for truing the surface of the above-mentioned polishing pad, so as to be able to restore the surface roughness of the polishing pad to ensure the material removal rate and polishing uniformity of the polishing pad.

[0043] The temperature sensor 30 can monitor and obtain the temperature signal of the polishing pad 10 in real time, and transmit the temperature signal to the laser emitter at a specific frequency. The temperature signal may include the average temperature and / or local temperature of the polishing pad 10.

[0044] The laser generator 40 mainly generates a laser beam with a high energy density. After focusing, it directly irradiates the surface of the polishing pad 10, converting light energy into heat energy, thereby achieving the heating of the polishing pad 10. The laser generator 40 can adjust the heating temperature by controlling the energy of the laser, thereby realizing the heating and cooling of the polishing pad 10.

[0045] As the grinding time increases, the temperature of the polishing pad 10 becomes higher and higher, which will affect the grinding rate and grinding uniformity. The cooperation of the temperature sensor 30 and the laser generator 40 in the grinding device 100 of the present application can control the temperature of the polishing pad 10 within a specified temperature range, thereby controlling the grinding rate and improving the grinding uniformity, which is beneficial to the control of the CMP process and the improvement of the planarization effect of the wafer 50. Moreover, since the laser generator 40 has a very fast temperature response speed, the temperature of the polishing pad can be adjusted quickly and accurately by using the laser generator 40 and the temperature sensor 30.

[0046] In addition, generally before grinding the wafer 50, it is necessary to first let the polishing pad 10 grind some shims to preheat the polishing pad 10, but the temperature of this preheating cannot be controlled, and it will also cause consumption of the polishing pad. The grinding device 100 in the present application can replace the preheating function of the shim, not only saving a large amount of consumable costs and time costs, but also accurately controlling the preheating temperature.

[0047] In some embodiments, the laser generator 40 can only heat a part, and use the rotation of the polishing pad 10 to achieve the temperature control of the entire polishing pad 10, which can save the area or quantity of the laser generator 40.

[0048] For example, the laser generator 40 can emit laser vertically downward. When the laser generator 40 heats the polishing pad 10 below it during the rotation of the polishing pad 10, the movement trajectory of the laser generator 40 relative to the polishing pad 10 is the heated area (which can be called the temperature control area of the polishing pad 10). This temperature control area will quickly rotate to the lower part of the grinding head 20 along the first direction, so that the wafer 50 can be ground at a specified temperature.

[0049] It should be noted that when the laser generator 40 does not emit laser vertically downward, but emits laser at a certain angle, the movement trajectory of the laser generator 40 does not completely coincide with the temperature control area in the top view direction, but has a corresponding relationship, which is related to the laser emission angle.

[0050] In some embodiments, the grinding disc 10 rotates along a first direction around the center O of the grinding disc 10, the grinding head 20 has a first side 21 and a second side 22, and the direction of the grinding head 20 from the first side 21 to the second side 22 is consistent with the first direction. For example, there is a position P on the grinding disc 10, and when the grinding disc 10 rotates along the first direction, the position P first passes through the first side 21 and then passes through the second side 22.

[0051] For example, Figure 2 As shown, the first direction is the clockwise direction, and the grinding disc 10 rotates clockwise around the center O. When the grinding disc 10 rotates clockwise, the position P first passes through the first side 21 of the grinding head 20, and then passes through the second side 22 of the grinding head 20. That is, the first side 21 is closer to the position P, and the second side 22 is farther from the position P.

[0052] See also Figure 3 , Figure 3 It is a structural schematic diagram of the grinding disc, grinding head, laser generator and temperature sensor provided in some embodiments of the present application, mainly showing the positions of the laser generator 40 and the temperature sensor 30 relative to the grinding head 20 and the grinding disc 10.

[0053] Position Q on the grinding disc 10 will first pass through the laser generator 40 and then pass through the temperature sensor 30 during the rotation process along the first direction. When the grinding disc 10 rotates along the first direction, position Q is the position where the laser generator 40 is about to heat. After heating, position Q immediately moves to the bottom of the grinding head 20, so as to grind the wafer 50 at the heated temperature. After that, position Q moves to the bottom of the temperature sensor 30 again, recorded as position Q', and the temperature sensor 30 obtains the temperature of position Q' and feeds the temperature back to the laser generator 40. The laser generator 40 can adjust its heating temperature according to the temperature. If the temperature of position Q' is not within the specified temperature range, the parameters of the laser generator 40 are adjusted so that the temperature of the laser emitted on the grinding disc 10 is restored to the specified temperature range.

[0054] The dotted area is the temperature control area T below the grinding head 20. When the movement trajectory of the laser generator 40 relative to the grinding disk 10 (i.e., the temperature control area T) covers the positive projection of the grinding head 20 on the grinding disk 10, the entire wafer 50 can be ground at this temperature, that is, the grinding temperature of the entire wafer 50 can be controlled.

[0055] It should be noted that the present application does not limit the shapes of the laser generator 40 and the temperature sensor 30. The laser generator 40 may be Figure 3 The strip shape shown may also be composed of a plurality of laser generating units, and the temperature sensor 30 is the same.

[0056] In some embodiments, the distance from the temperature sensor 30 to the second side 22 is less than the distance from the temperature sensor 30 to the first side 21, and the distance from the laser generator 40 to the first side 21 is less than the distance from the laser generator 40 to the second side 22. In other words, the laser generator 40 is disposed closer to the first side 21, while the temperature sensor 30 is disposed closer to the second side 22.

[0057] By disposing the laser generator 40 on the first side 21, the temperature control region T can grind the wafer 50 in a timely manner, so that the grinding temperature is more accurate. Because if the laser generator 40 is disposed on the second side 22, the heated temperature control region T needs to make a large circle to reach below the wafer 50. And the temperature sensor 30 is disposed closer to the second side 22, which can timely monitor the temperature of the temperature control region T after grinding, and the obtained temperature is more accurate, so that the temperature control of the laser generator 40 is more precise.

[0058] In some embodiments, the laser generator 40 is fixedly disposed relative to the grinding head 20, and the temperature sensor 30 is fixedly disposed relative to the grinding head 20. That is to say, the relative positions of the laser generator 40 and the temperature sensor 30 with respect to the grinding head 20 are unchanged, which can ensure that the temperature control region T always covers the orthographic projection of the grinding head 20 on the grinding disk 10. Otherwise, if the grinding head 20 shakes, some positions of the grinding head 20 may not be within the temperature control region T.

[0059] Please refer to Figure 4 , Figure 4 which is a schematic structural diagram of a grinding disk, a grinding head, a laser generator, and a temperature sensor provided by some embodiments of the present application, mainly showing that the grinding disk 10 has a plurality of temperature control regions T, such as a first temperature control region T1, a second temperature control region T2, a third temperature control region T3, a fourth temperature control region T4, and a fifth temperature control region T5.

[0060] The difference between this embodiment and the above Figure 3 embodiment is that the working surface 11 of the grinding disk 10 includes a plurality of temperature control regions T, the laser generator 40 includes a plurality of laser generating units 41, one laser generating unit 41 correspondingly controls the temperature of one temperature control region T, and the temperatures of at least two temperature control regions T are different.

[0061] It can be understood that the grinding temperature control of different regions of the wafer 50 can be achieved by designing the positions of multiple laser generating units 41. The trajectory formed by one laser generating unit 41 moving relative to the grinding disc 10 is a corresponding temperature control region T. The combination of the trajectories of multiple laser generating units 41 can achieve the temperature control of multiple temperature control regions T, so as to respectively control the temperatures of different partitions (corresponding to the temperature control regions T) of the wafer 50.

[0062] For example, multiple laser generating units 41 respectively control the first temperature control region T1, the second temperature control region T2, the third temperature control region T3, the fourth temperature control region T4 and the fifth temperature control region T5, and the temperatures of at least two temperature control regions T are different.

[0063] In some embodiments, the temperature sensor 30 includes multiple temperature sensing units 31. The multiple temperature sensing units 31 are coupled to the multiple laser generating units 41 in a one-to-one correspondence, and one temperature sensing unit 31 is configured to feedback the temperature of one temperature control region T to one laser generating unit 41, so that the temperature control of different partitions of the wafer 50 is more timely and accurate.

[0064] In the actual process, the front-layer process of the wafer 50 may make the structure of the first partition corresponding to the first temperature control region T1 thicker. Then, the temperature of the first temperature control region T1 can be controlled to be higher to achieve the thickness uniformity of the wafer 50 after grinding. Therefore, the grinding device 100 of this embodiment can achieve the grinding temperature control of different partitions of the wafer 50 and solve some problems brought by the wafer 50 in the process.

[0065] In some embodiments, multiple laser generating units 41 are arranged adjacent to each other in a straight line, so that the boundaries of multiple temperature control regions T are concentric circles.

[0066] In some embodiments, during the movement of the grinding disc 10, the orthographic projection of the grinding head 20 on the grinding disc 10 is within the orthographic projection range of the multiple temperature control regions T, so that the temperature of the entire wafer 50 can be controlled.

[0067] Specifically, the size of the laser generator 40 along the extension direction of the straight line is greater than or equal to the diameter of the grinding head 20.

[0068] In some embodiments, multiple laser generating units 41 are arranged adjacent to each other along the radial direction of the grinding disc 10, that is to say, the arrangement direction of multiple laser generating units 41 can pass through the center O of the grinding disc 10.

[0069] The grinding device provided by the embodiment of the present application can quickly and accurately raise and lower the temperature of the grinding disk 10 by using laser and sensing technologies, and its temperature control area can be accurate to the specific position of the wafer 50, achieving zonal control of the temperature of the wafer 50 during grinding, thereby controlling the grinding rate and improving the grinding uniformity.

[0070] The description of the above embodiments is only used to help understand the technical solutions and their core ideas of the present application; those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A grinding device, characterized in that: include: A grinding disc and a grinding head matched with the grinding disc; A temperature sensor is located on one side of the working surface of the grinding disc and is configured to obtain a temperature signal of the grinding disc and output the temperature signal; A laser generator is located at one side of the working surface of the grinding disk and is coupled to the temperature sensor. The laser generator is configured to heat the grinding disk according to the temperature signal.

2. The grinding device according to claim 1, characterized in that: The grinding disc rotates around the center of the grinding disc in a first direction, the grinding head has a first side and a second side, and the direction of the grinding head from the first side to the second side is consistent with the first direction; The distance from the temperature sensor to the second side is smaller than the distance from the temperature sensor to the first side; The distance from the laser generator to the first side is smaller than the distance from the laser generator to the second side.

3. The grinding device according to claim 1, characterized in that: The grinding head is located at one side of the working surface of the grinding disc, and the grinding head is fixed relative to the center of the grinding disc; The laser generator is fixedly arranged relative to the grinding head, and the temperature sensor is fixedly arranged relative to the grinding head.

4. The grinding device according to claim 1, characterized in that: The working surface of the grinding disc includes a plurality of temperature control zones; The laser generator includes a plurality of laser generating units, one of the laser generating units controls the temperature of one of the temperature control areas, and the temperatures of at least two of the temperature control areas are different.

5. The grinding device according to claim 4, characterized in that: The plurality of laser generating units are arranged adjacent to each other in a straight line, and a trajectory formed by the movement of one laser generating unit relative to the grinding disk is the corresponding temperature control area.

6. The grinding device according to claim 5, characterized in that: During the movement of the grinding disk, the orthographic projection of the grinding head on the grinding disk is located within the range of the orthographic projections of the plurality of temperature control areas.

7. The grinding device according to claim 6, characterized in that: The dimension of the laser generator along the extension direction of the straight line is greater than or equal to the diameter of the grinding head.

8. The grinding device according to claim 5, characterized in that: The plurality of laser generating units are arranged adjacent to each other in a radial direction of the grinding disk.

9. The grinding device according to claim 1, characterized in that: The diameter of the grinding head is smaller than the radius of the grinding disk, and the minimum distance between the edge of the grinding head and the center of the grinding disk is greater than 0.

10. The grinding device according to claim 4, characterized in that: The temperature sensor includes a plurality of temperature sensing units, the plurality of temperature sensing units are coupled to the plurality of laser generating units in a one-to-one correspondence, and one temperature sensing unit is configured to feed back the temperature of one of the temperature control areas to one of the laser generating units.

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