Chemical mechanical polishing apparatus and method of conditioning chemical mechanical planarization

Abstract

The embodiment of the present disclosure relates to a chemical mechanical polishing device and a method for adjusting chemical mechanical planarization. The chemical mechanical polishing device comprises: a polishing pad carrying a polishing pad; a polishing head located above the polishing pad, the polishing head carrying a wafer on one side close to the polishing pad; a first detection device arranged outside the wafer, used for detecting the thickness change of the wafer, and generating a thickness difference signal according to the thickness change; a control device connected with the first detection device, used for receiving the thickness difference signal, and generating a control signal according to the thickness difference signal, the control signal being used for adjusting the first distance between the polishing pad and the polishing head, so that the polishing rate of the polishing pad polishing the wafer remains unchanged. According to the thickness difference signal, the control signal for adjusting the first distance between the polishing pad and the polishing head is generated, so that the change of the polishing pad and the wafer thickness does not affect the polishing rate of the chemical mechanical polishing process, thereby ensuring that the polishing process of the chemical mechanical polishing process is stably carried out.

Description

Technical Field

[0001] This disclosure relates to the field of semiconductor technology, and in particular to a chemical mechanical polishing apparatus and a method for adjusting chemical mechanical planarization. Background Technology

[0002] The polishing plate is the support platform for chemical mechanical polishing (CMP). It is used to support the polishing pad on the wafer surface and drive the polishing pad to rotate. In a typical CMP process, the position of the polishing plate remains fixed. As the CMP process proceeds, the thickness of both the polishing pad and the wafer changes, which affects the polishing rate of the CMP process and makes the polishing process unstable. Summary of the Invention

[0003] This disclosure provides a chemical mechanical polishing (CMP) apparatus and a method for adjusting CMP planarization, which can eliminate the influence of thickness variations of the polishing pad and wafer on the polishing rate of the CMP process, thereby ensuring the stable operation of the CMP process.

[0004] This disclosure provides a chemical mechanical grinding apparatus, comprising:

[0005] Grinding disc, used to hold the polishing pad;

[0006] The grinding head is located above the grinding disk, and the side of the grinding head closest to the grinding disk supports the wafer;

[0007] The first detection device is located on the outside of the wafer and is used to detect the thickness change of the wafer and generate a thickness difference signal based on the thickness change.

[0008] A control device, connected to a first detection device, is used to receive a thickness difference signal and generate a control signal based on the thickness difference signal. The control signal is used to adjust a first gap between the polishing pad and the polishing head so that the polishing rate of the polishing pad polishing the wafer remains constant.

[0009] In one embodiment, the chemical mechanical grinding apparatus includes:

[0010] The second detection device, located on the outside of the wafer, is used to detect the wear of the polishing pad and generate a wear signal based on the wear amount.

[0011] The control device is connected to the second detection device, and the control device is also used to generate the control signal based on the wear signal and the thickness difference signal.

[0012] In one embodiment, the chemical mechanical grinding apparatus further includes:

[0013] The grinding disc drive device is connected to the control device and is used to adjust the first spacing according to the control signal.

[0014] In one embodiment, the chemical mechanical grinding apparatus further includes:

[0015] A pressure detection device is used to detect the polishing pressure between the polishing pad and the wafer, and to generate a pressure detection signal based on the polishing pressure.

[0016] The control device is connected to the pressure detection device to receive the pressure detection signal and generate a pressure adjustment signal based on the pressure detection signal and the thickness difference signal. The pressure adjustment signal is used to adjust the polishing pressure between the polishing pad and the wafer so that the polishing rate remains constant.

[0017] In one embodiment, the chemical mechanical grinding apparatus further includes:

[0018] A speed detection device is used to detect the rotational speed of the grinding head and generate a speed detection signal based on the rotational speed.

[0019] The control device is connected to the speed detection device to receive the speed detection signal and generate a speed adjustment signal based on the speed detection signal. The speed adjustment signal is used to adjust the rotation speed of the grinding head so that the grinding rate remains constant.

[0020] In one embodiment, the chemical mechanical grinding apparatus further includes:

[0021] The grinding head drive device, connected to the control device, is used to adjust the rotational speed of the grinding head according to the speed adjustment signal; it is also used to adjust the first gap according to the control signal.

[0022] In the aforementioned chemical mechanical polishing (CMP) equipment, the first detection device detects the thickness change of the wafer and generates a thickness difference signal based on the thickness change. The control device receives the thickness difference signal and generates a control signal based on the thickness difference signal. The control signal is used to adjust the first gap between the polishing pad and the polishing head so that the polishing speed of the polishing pad polishing the wafer remains constant. The control signal generated based on the thickness difference signal adjusts the first gap between the polishing pad and the polishing head so that the changes in the thickness of the polishing pad and the wafer do not affect the polishing rate of the CMP process, thereby ensuring the stable operation of the CMP process.

[0023] This disclosure also provides a method for adjusting chemical mechanical planarization, which involves using a chemical mechanical polishing (CMP) apparatus to planarize the surface of a wafer. The CMP apparatus includes a polishing disc and a polishing head. The polishing disc is used to support a polishing pad, and the polishing head is located above the polishing disc. The wafer is supported on the side of the polishing head closest to the polishing disc. The method for adjusting CMP includes:

[0024] The thickness change of the wafer is detected, and a thickness difference signal is generated based on the thickness change;

[0025] A control signal is generated based on the thickness difference signal;

[0026] The first gap between the polishing pad and the polishing head is adjusted according to the control signal so that the polishing rate of the polishing pad polishing the wafer remains constant.

[0027] In one embodiment, the method for adjusting chemical mechanical planarization further includes:

[0028] The wear amount of the polishing pad is detected, and a wear signal is generated based on the wear amount;

[0029] The control signal generated based on the thickness difference signal includes:

[0030] Control signals are generated based on thickness difference signals and wear signals.

[0031] In one embodiment, the method for adjusting chemical mechanical planarization further includes:

[0032] The grinding pressure between the polishing pad and the wafer is detected, and a pressure detection signal is generated based on the grinding pressure.

[0033] A pressure adjustment signal is generated based on the pressure detection signal and the thickness difference signal;

[0034] The pressure between the polishing pad and the wafer is adjusted according to the pressure regulation signal to keep the polishing rate constant.

[0035] In one embodiment, the method for adjusting chemical mechanical planarization further includes:

[0036] The rotational speed of the grinding head is detected, and a speed detection signal is generated based on the rotational speed.

[0037] A speed adjustment signal is generated based on the speed detection signal. The speed adjustment signal is used to adjust the rotation speed of the grinding head so that the grinding rate remains constant.

[0038] The above-mentioned method for adjusting chemical mechanical planarization generates a control signal based on the wafer thickness variation to adjust the first gap between the polishing pad and the polishing head, so as to keep the polishing speed of the polishing pad on the wafer constant. This method ensures that the changes in the thickness of the polishing pad and the wafer do not affect the polishing rate of the chemical mechanical polishing process, thereby ensuring the stable operation of the chemical mechanical polishing process. Attached Figure Description

[0039] To more clearly illustrate the technical solutions in the embodiments or related technologies of this disclosure, the accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1 This is a cross-sectional schematic diagram of the chemical mechanical grinding apparatus in the first embodiment;

[0041] Figure 2 This is a cross-sectional schematic diagram of the chemical mechanical grinding apparatus in the second embodiment;

[0042] Figure 3 This is a cross-sectional schematic diagram of the chemical mechanical grinding apparatus in the third embodiment;

[0043] Figure 4 This is a cross-sectional schematic diagram of the chemical mechanical grinding apparatus in the fourth embodiment;

[0044] Figure 5 This is a flowchart illustrating a method for adjusting chemical mechanical planarization in one embodiment;

[0045] Figure 6 This is a flowchart illustrating a method for adjusting chemical mechanical planarization in another embodiment;

[0046] Figure 7 This is a flowchart illustrating a method for adjusting chemical mechanical planarization in another embodiment.

[0047] Explanation of reference numerals in the attached figures:

[0048] 102. Grinding disc; 104. Polishing pad; 106. Grinding head; 108. Wafer; 110. First detection device; 112. Control device; 114. Second detection device; 116. Grinding disc drive device; 118. Pressure detection device; 120. Speed ​​detection device; 122. Grinding head drive device; 124. End point detection device; 202. Base; 204. Positioning ring; 206. First groove; 208. First opening; 210. Second opening; 212. Base; 214. Second groove; 216. Rotating shaft. Detailed Implementation

[0049] To facilitate understanding of the embodiments of this disclosure, a more complete description of the embodiments of this disclosure will be provided below with reference to the accompanying drawings. Preferred embodiments of the embodiments of this disclosure are shown in the drawings. However, the embodiments of this disclosure can be implemented in many different forms and are not limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

[0050] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which embodiments of this disclosure belong. The terminology used herein in the description of embodiments of this disclosure is for the purpose of describing particular embodiments only and is not intended to be limiting of the embodiments of this disclosure. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0051] In the description of the embodiments of this disclosure, it should be understood that the terms "upper", "lower", "vertical", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the method or positional relationship shown in the drawings. They are only for the convenience of describing the embodiments of this disclosure and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this disclosure.

[0052] It is understood that the terms "first," "second," etc., as used in this disclosure may be used herein to describe various elements, but these elements are not limited by these terms. These terms are used only to distinguish one element from another. For example, without departing from the scope of this disclosure, a first detection device may be referred to as a second detection device, and similarly, a second detection device may be referred to as a first detection device. Both the first detection device and the second detection device are detection devices, but they are not the same detection device.

[0053] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this disclosure, "a plurality of" means at least two, such as two, three, etc., unless otherwise expressly specified. In the description of this disclosure, "several" means at least one, such as one, two, etc., unless otherwise expressly specified.

[0054] It is understood that the term "connection" in the following embodiments should be understood as "electrical connection," "communication connection," etc., if the connected circuits, modules, units, etc., have electrical signal or data transmission with each other.

[0055] Figure 1 This is a cross-sectional schematic diagram of the chemical mechanical grinding apparatus in the first embodiment, as shown below. Figure 1As shown, in this embodiment, a chemical mechanical polishing (CMP) apparatus is provided, including: a polishing disc 102, a polishing head 106, a first detection device 110, and a control device 112. The polishing disc 102 is used to support a polishing pad 104. The polishing head 106 is located above the polishing disc 102, and a wafer 108 is supported on the side of the polishing head 106 near the polishing disc 102. The polishing pad 104 is located on the side of the polishing disc 102 near the polishing head 106. The wafer 108 is polished by the polishing pad 104 to achieve the purpose of making the surface of the wafer 108 near the polishing disc 102 flat. The side of the polishing disc 102 that supports the polishing pad 104 is located above the polishing head 106. The first detection device 110 is disposed on the outer side of the wafer 108 and is used to detect the thickness change of the wafer 108 and generate a thickness difference signal based on the thickness change. The outer side is the edge of the wafer 108. The control device 112 is connected to the first detection device 110 and is used to receive the thickness difference signal and generate a control signal based on the thickness difference signal. The control signal is used to adjust the first distance D1 between the polishing pad 102 and the polishing head 106 so that the polishing rate of the polishing pad 104 polishing the wafer 108 remains constant.

[0056] In the aforementioned chemical mechanical polishing (CMP) equipment, the first detection device 110 detects the thickness change of the wafer 108 and generates a thickness difference signal based on the thickness change. The control device 112 receives the thickness difference signal and generates a control signal based on the thickness difference signal. The control signal is used to adjust the first gap D1 between the polishing pad 102 and the polishing head 106 so that the polishing speed of the polishing pad 104 polishing the wafer 108 remains constant. The control signal generated based on the thickness difference signal is used to adjust the first gap D1 between the polishing pad 102 and the polishing head 106 so that the wear of the polishing pad 104 and the thickness change of the wafer 108 will not affect the polishing rate of the CMP process, thereby ensuring that the CMP process can proceed stably.

[0057] Continue to refer to Figure 1In one embodiment, the polishing head 106 includes a base 202 and a positioning ring 204 located on a first surface of the base 202. The positioning ring 204 is located outside the wafer 108. The first surface of the base 202 is the side of the base 202 near the polishing pad 104 (the side of the polishing head 106 that carries the wafer 108) and contacts the edge of the wafer 108. The distance between the positioning ring 204 and the polishing pad 104 is greater than the distance between the wafer 108 and the polishing pad 104. A portion of the sidewall of the positioning ring 204 and the first surface of the base 202 forms the inner wall of a first groove 206. When the polishing head 106 carries the wafer 108, the wafer 108 is located in the first groove 206, and the surface of the wafer 108 that needs to be planarized protrudes from the surface of the positioning ring 204. Exemplarily, the wafer 108 is adsorbed by a vacuum adsorption device (not shown) penetrating the base 202 to fix the wafer 108 on the surface of the polishing head 106. Optionally, a flexible buffer pad is provided between the wafer 108 and the base 202 to achieve a seal between the wafer 108 and the first groove 206, thereby adsorbing the wafer 108. Optionally, a first opening 208 is provided on the side of the positioning ring 204 near the polishing pad 104, and the first detection device 110 is housed in the first opening 208. Exemplarily, the base 202 and the positioning ring 204 are detachably connected. In other embodiments, the first detection device 110 is located on the side wall of the positioning ring 204 away from the first groove 206. This arrangement can prevent byproducts generated during chemical mechanical polishing from adsorbing onto the inner wall of the first opening 208 and falling onto the polishing pad 104, thus affecting the normal operation of the chemical mechanical polishing process.

[0058] Optionally, the first detection device 110 may include, but is not limited to, a displacement sensor.

[0059] Figure 2 This is a cross-sectional schematic diagram of the chemical mechanical grinding apparatus in the second embodiment, as shown below. Figure 2 As shown, in this embodiment, the chemical mechanical polishing (CMP) apparatus includes: a second detection device 114, which is disposed on the outer side of the wafer 108, for detecting the wear amount of the polishing pad 104 and generating a wear signal based on the wear amount; and a control device 112 connected to the second detection device 114, which is also used to generate a control signal based on the wear signal and the thickness difference signal. By setting the second detection device 114, the wear amount of the polishing pad 104 during the CMP process can be detected, and a more accurate control signal can be generated based on the wear signal and the thickness difference signal, resulting in higher accuracy in adjusting the first gap D1 between the polishing disc 102 and the polishing head 106, and smaller fluctuations in the polishing rate of the polishing pad 104 polishing the wafer 108.

[0060] Continue to refer to Figure 2In one embodiment, the positioning ring 204 has a second opening 210 on the side near the polishing pad 104, and the second detection device 114 is housed in the second opening 210. In other embodiments, the second detection device 114 is located on the side wall of the positioning ring 204 away from the first groove 206. This arrangement prevents byproducts generated during chemical mechanical polishing from adhering to the inner wall of the second opening 210 and falling onto the polishing pad 104, thus affecting the normal operation of the chemical mechanical polishing process. Optionally, the second opening 210 and the first opening 208 are located on opposite sides of the side of the positioning ring 204 near the polishing pad 104. This arrangement prevents the weight of the first detection device 110 and the second detection device 114 and the installation process from affecting the levelness of the polishing head 106. Optionally, the second detection device 114 and the first detection device 110 are located on the opposite sidewall of the positioning ring 204 away from the first groove 206. This arrangement can also avoid the influence of the weight of the first detection device 110 and the second detection device 114 and the installation process on the levelness of the grinding head 106.

[0061] Optionally, the second detection device 114 may include, but is not limited to, a displacement sensor.

[0062] Continue to refer to Figure 2 In one embodiment, the chemical mechanical polishing apparatus further includes a polishing disc drive device 116, which is connected to a control device 112 and is used to receive control signals generated by the control device 112 and adjust the first gap D1 according to the control signals. Specifically, the polishing disc drive device 116 adjusts the first gap D1 by controlling the movement of the polishing disc 102 in a first direction, which is a direction perpendicular to both the polishing disc 102 and the polishing head 106, represented by the Y direction in the figure. As the polishing pad 104 wears and the thickness decreases during wafer planarization, the polishing disc drive device 116 shortens the first gap D1 by controlling the polishing disc 102 to move closer to the polishing head 106 in the first direction, thereby offsetting the effects of the wear of the polishing pad 104 and the thickness change of the wafer 108 on the polishing rate.

[0063] Optionally, the grinding disc drive 116 may include, but is not limited to, a servo motor.

[0064] Continue to refer to Figure 2In one embodiment, the chemical mechanical polishing apparatus further includes a base 212, a polishing disc 102 mounted on the base 212, and a polishing disc drive device 116 mounted inside the base 212. The polishing disc drive device 116 controls the movement of the polishing disc 102 in a first direction by driving the base 212 to move in a first direction according to a control signal. Optionally, the polishing disc 102 is fixedly connected to the base 212. In this case, the polishing disc drive device 116 drives the base 212 to move closer to the polishing head 106, thereby moving the polishing disc 102 closer to the polishing head 106 to shorten the first gap D1. Conversely, the polishing disc drive device 116 drives the base 212 to move away from the polishing head 106, thereby moving the polishing disc 102 away from the polishing head 106 to increase the first gap D1. Optionally, the grinding disc 102 and the base 212 are movably connected. In this case, the grinding disc driving device 116 drives the base 212 to move away from the grinding head 106, so that the grinding disc 102 moves closer to the grinding head 106 to shorten the first gap D1. The grinding disc driving device 116 drives the base 212 to move closer to the grinding head 106, so that the grinding disc 102 moves away from the grinding head 106 to increase the first gap D1.

[0065] Optionally, a second groove 214 is formed on the side of the grinding disc 102 that supports the polishing pad 104. The polishing pad 104 is adsorbed onto the surface of the grinding disc 102 by a vacuum adsorption device that penetrates the grinding disc 102. At this time, part of the surface of the polishing pad 104 is located at the opening of the second groove 214. Optionally, a flexible buffer pad can also be provided between the polishing pad 104 and the bottom of the second groove 214. The flexible buffer pad achieves a seal between the polishing pad 104 and the second groove 214, thereby achieving the purpose of adsorbing the polishing pad 104.

[0066] Continue to refer to Figure 2 In one embodiment, the chemical mechanical polishing (CMP) apparatus further includes: a pressure detection device 118, which detects the polishing pressure between the polishing pad 104 and the wafer 108 and generates a pressure detection signal based on the polishing pressure; and a control device 112 connected to the pressure detection device 118, which receives the pressure detection signal and generates a pressure adjustment signal based on the pressure detection signal and a thickness difference signal. The pressure adjustment signal is used to adjust the polishing pressure between the polishing pad 104 and the wafer 108 to maintain a constant polishing rate. By detecting pressure changes between the polishing pad 104 and the wafer 108, the polishing pressure between them is controlled and adjusted, thereby eliminating the influence of polishing pressure changes on the polishing rate and improving the accuracy of polishing rate control.

[0067] In one embodiment, the pressure detection device 118 includes a pressure sensor. Optionally, the pressure sensor is located on the sidewall of the second groove 214 and in contact with the surface of the polishing pad 104 near the second groove 214. This arrangement allows for real-time and accurate detection of the polishing pressure between the polishing pad 104 and the wafer 108.

[0068] Figure 3 This is a cross-sectional schematic diagram of the chemical mechanical grinding apparatus in the third embodiment, as shown below. Figure 3 As shown, in this embodiment, the chemical mechanical grinding apparatus further includes: a speed detection device 120, which detects the rotational speed of the grinding head 106 and generates a speed detection signal based on the rotational speed; and a control device 112 connected to the speed detection device 120, which receives the speed detection signal and generates a speed adjustment signal based on the speed detection signal, which adjusts the rotational speed of the grinding head 106 to keep the grinding rate constant. By detecting the rotational speed of the grinding head 106 and controlling and adjusting the rotational speed of the grinding head 106, the influence of changes in the rotational speed of the grinding head 106 on the grinding rate is eliminated, thereby improving the accuracy of controlling the grinding rate.

[0069] Optionally, the speed detection device 120 may include, but is not limited to, a speed detector and an angular velocity detector.

[0070] like Figure 3 As shown, in one embodiment, the chemical mechanical grinding apparatus further includes a grinding head drive device 122, which is connected to a control device 112 and is used to adjust the rotational speed of the grinding head 106 according to a speed adjustment signal.

[0071] In one embodiment, the grinding head drive device 122 is further configured to adjust the first pitch D1 according to a control signal. Specifically, the grinding head drive device 122 adjusts the first pitch D1 by controlling the movement of the grinding head 106 in a first direction, which is a direction perpendicular to both the grinding disk 102 and the grinding head 106, indicated by the Y direction in the figure. As the polishing pad 104 wears and the thickness of the wafer 108 decreases during planarization, the grinding head drive device 122 shortens the first pitch D1 by controlling the grinding head 106 to move closer to the grinding disk 102 in the first direction, thereby offsetting the effects of the wear of the polishing pad 104 and the thickness change of the wafer 108 on the grinding rate.

[0072] Optionally, the grinding head drive device 122 may include, but is not limited to, a servo motor.

[0073] Continue to refer to Figure 3In one embodiment, the chemical mechanical polishing apparatus further includes a rotating shaft 216, a polishing head 106 mounted on the rotating shaft 216, and a polishing head drive device 122 mounted inside the rotating shaft 216. The polishing head drive device 122 drives the rotating shaft 216 to move in a first direction according to a control signal, thereby controlling the movement of the polishing head 106 in the first direction. Optionally, the polishing head 106 is fixedly connected to the rotating shaft 216. In this case, the polishing head drive device 122 moves the rotating shaft 216 towards the polishing disk 102, thereby shortening the first gap D1 by moving the polishing head 106 towards the polishing disk 102. The polishing head drive device 122 also drives the rotating shaft 216 away from the polishing disk 102 to increase the first gap D1 by moving the polishing head 106 away from the polishing disk 102. Optionally, the grinding head 106 is movably connected to the rotating shaft 216. In this case, the grinding head driving device 122 drives the rotating shaft 216 to move away from the grinding disk 102, thereby causing the grinding head 106 to move closer to the grinding disk 102 to shorten the first gap D1. The grinding head driving device 122 also drives the rotating shaft 216 to move closer to the grinding disk 102, thereby causing the grinding head 106 to move away from the grinding disk 102 to increase the first gap D1.

[0074] Figure 4 This is a cross-sectional schematic diagram of the chemical mechanical grinding apparatus in the fourth embodiment, as shown below. Figure 4 As shown, in this embodiment, the grinding head drive device 122 includes a servo motor, and the chemical mechanical polishing (CMP) equipment further includes an endpoint detection device 124. The endpoint detection device 124 is used to detect the current of the servo motor and generate a current detection signal based on the current. The control device 112 is connected to the endpoint detection device 124 and is also used to determine the endpoint of the CMP based on the current detection signal. When the CMP approaches its endpoint, the friction between the polishing pad 104 and the wafer 108 begins to change, and the current of the servo motor driving the grinding head 106 to rotate changes to ensure that the rotation speed of the grinding head 106 remains constant. Therefore, monitoring the current of the servo motor can determine the endpoint of the CMP. With this setting, the grinding can be stopped at the endpoint of the CMP, reducing process costs and enabling the CMP planarization process to run automatically.

[0075] In one embodiment, the endpoint detection device 124 further includes a photoelectric detection device for detecting the film thickness of a preset thin film on the surface of the wafer 108 and generating a film thickness detection signal based on the film thickness; the control device 112 is also used to determine the endpoint of the chemical mechanical polishing based on the film thickness detection signal. The preset thin film is a film layer that needs to be chemically mechanically polished for chemical mechanical planarization.

[0076] Figure 5This is a flowchart illustrating a method for adjusting chemical mechanical planarization in one embodiment, as shown below. Figure 1 , Figure 5 As shown, in this embodiment, a method for adjusting chemical mechanical planarization is provided. A chemical mechanical polishing (CMP) apparatus is used to planarize the surface of a wafer 108. The CMP apparatus includes a polishing disc 102 and a polishing head 106. The polishing disc 102 supports a polishing pad 104, and the polishing head 106 is located above the polishing disc 102. The wafer 108 is supported on the side of the polishing head 106 closest to the polishing disc 102. The method for adjusting CMP includes:

[0077] S102, detect the thickness change of the wafer, and generate a thickness difference signal based on the thickness change.

[0078] Specifically, the thickness change of the wafer 108 is detected by the first detection device 110, and a thickness difference signal is generated based on the thickness change. Optionally, the first detection device 110 is disposed on the outer side of the wafer 108, which is the edge of the wafer 108. Optionally, the first detection device 110 includes, but is not limited to, a displacement sensor.

[0079] S104 generates a control signal based on the thickness difference signal.

[0080] Specifically, the control device 112, which is connected to the first detection device 110, receives the thickness difference signal and generates a control signal based on the thickness difference signal.

[0081] S106, adjust the first gap between the grinding disc and the grinding head according to the control signal.

[0082] Specifically, the first gap D1 between the polishing disc 102 and the polishing head 106 is adjusted according to the control signal generated by the control device 112, so that the polishing rate of the polishing pad 104 polishing the wafer 108 remains constant. Figure 2 As shown, exemplarily, the grinding disc drive device 116 receives the control signal generated by the control device 112 and adjusts the first pitch D1 according to the control signal. Optionally, the grinding disc drive device 116 includes, but is not limited to, a servo motor. Specifically, the grinding disc drive device 116 adjusts the first pitch D1 by controlling the movement of the grinding disc 102 in a first direction, which is a direction perpendicular to both the grinding disc 102 and the grinding head 106, represented by the Y direction in the figure. As the polishing pad 104 wears and the thickness decreases during wafer planarization, the grinding disc drive device 116 shortens the first pitch D1 by controlling the grinding disc 102 to move closer to the grinding head 106 in the first direction, thereby offsetting the effects of the wear of the polishing pad 104 and the thickness change of the wafer 108 on the grinding rate.

[0083] The above-mentioned method for adjusting chemical mechanical planarization generates a control signal based on the thickness variation of wafer 108 to adjust the first gap D1 between the polishing pad 102 and the polishing head 106, so that the polishing speed of polishing pad 104 polishing wafer 108 remains constant. This method ensures that the wear of polishing pad 104 and the thickness variation of wafer 108 do not affect the polishing rate of chemical mechanical polishing process, thereby ensuring the stable operation of the chemical mechanical polishing process.

[0084] like Figure 2 As shown, in one embodiment, the method for adjusting chemical mechanical planarization further includes: detecting the wear amount of the polishing pad and generating a wear signal based on the wear amount; specifically, detecting the wear amount of the polishing pad 104 and generating a wear signal based on the wear amount, thereby monitoring the changes of the polishing pad 104 during chemical mechanical polishing. Exemplarily, the wear amount of the polishing pad 104 is detected by a second detection device 114, and a wear signal is generated based on the wear amount. Optionally, the second detection device 114 includes, but is not limited to, a displacement sensor. The step of generating a control signal based on a thickness difference signal includes: generating a control signal based on the thickness difference signal and the wear signal. Specifically, the control device 112 generates a control signal based on the received wear signal and thickness difference signal. By detecting the wear amount of the polishing pad 104 during chemical mechanical polishing, a more precise control signal can be generated based on the wear signal and the thickness difference signal, resulting in higher accuracy in adjusting the first distance D1 between the polishing disc 102 and the polishing head 106, and less fluctuation in the polishing rate of the polishing pad 104 polishing the wafer 108.

[0085] In one embodiment, the chemical mechanical polishing apparatus further includes a base 212, on which a polishing disc 102 is mounted. A polishing disc drive device 116 drives the base 212 to move in a first direction according to a control signal, thereby controlling the movement of the polishing disc 102 in the first direction. Optionally, the polishing disc 102 is fixedly connected to the base 212. In this case, the polishing disc drive device 116 drives the base 212 to move closer to the polishing head 106, thereby moving the polishing disc 102 closer to the polishing head 106 to shorten the first gap D1. Conversely, the polishing disc drive device 116 drives the base 212 to move away from the polishing head 106, thereby moving the polishing disc 102 away from the polishing head 106 to increase the first gap D1. Optionally, the grinding disc 102 and the base 212 are movably connected. In this case, the grinding disc driving device 116 drives the base 212 to move away from the grinding head 106, so that the grinding disc 102 moves closer to the grinding head 106 to shorten the first gap D1. The grinding disc driving device 116 drives the base 212 to move closer to the grinding head 106, so that the grinding disc 102 moves away from the grinding head 106 to increase the first gap D1.

[0086] Figure 6 This is a flowchart illustrating the method for adjusting chemical mechanical planarization in another embodiment, as shown below. Figure 4 , Figure 6 As shown, in one embodiment, the method for adjusting chemical mechanical planarization further includes:

[0087] S202 detects the polishing pressure between the polishing pad and the wafer, and generates a pressure detection signal based on the polishing pressure.

[0088] Specifically, the polishing pressure between the polishing pad 104 and the wafer 108 is detected in real time by the pressure detection device 118, and a pressure detection signal is generated based on the polishing pressure. Optionally, the pressure detection device 118 includes a pressure sensor.

[0089] S204 generates a pressure adjustment signal based on the pressure detection signal and the thickness difference signal.

[0090] Specifically, the control device 112 receives the pressure detection signal and generates a pressure adjustment signal based on the pressure detection signal and the thickness difference signal.

[0091] S206 adjusts the pressure between the polishing pad and the wafer according to the pressure adjustment signal to keep the polishing rate constant.

[0092] Specifically, the grinding disc drive device 116 and / or the grinding head drive device 122 adjust the grinding pressure between the polishing pad 104 and the wafer 108 according to the pressure adjustment signal to keep the grinding rate constant. By detecting the pressure change between the polishing pad 104 and the wafer 108, the grinding pressure between the polishing pad 104 and the wafer 108 is controlled and adjusted to eliminate the influence of the grinding pressure change on the grinding rate and improve the accuracy of the grinding rate control.

[0093] Figure 7 This is a flowchart illustrating the method for adjusting chemical mechanical planarization in another embodiment, as shown below. Figure 4 , Figure 7 As shown, in one embodiment, the method for adjusting chemical mechanical planarization further includes:

[0094] S302 detects the rotational speed of the grinding head and generates a speed detection signal based on the rotational speed.

[0095] Specifically, the rotational speed of the grinding head 106 is detected by the speed detection device 120, and a speed detection signal is generated based on the rotational speed. Optionally, the speed detection device 120 includes, but is not limited to, a speed detector and an angular velocity detector.

[0096] S304 generates a speed adjustment signal based on the speed detection signal. The speed adjustment signal is used to adjust the rotation speed of the grinding head so that the grinding rate remains constant.

[0097] Specifically, the control device 112 receives a speed detection signal and generates a speed adjustment signal based on the speed detection signal. The speed adjustment signal is used to adjust the rotational speed of the grinding head 106 to keep the grinding rate constant. By detecting the rotational speed of the grinding head 106 and controlling and adjusting the rotational speed of the grinding head 106, the influence of changes in the rotational speed of the grinding head 106 on the grinding rate is eliminated, thereby improving the accuracy of controlling the grinding rate.

[0098] In one embodiment, the polishing head drive device 122 includes a servo motor, and the method for adjusting chemical mechanical planarization further includes: detecting the current of the servo motor and generating a current detection signal based on the current; and determining the endpoint of the chemical mechanical polishing based on the current detection signal. Specifically, the endpoint detection device 124 detects the current of the servo motor and generates a current detection signal based on the current; the control device 112 determines the endpoint of the chemical mechanical polishing based on the current detection signal. When the chemical mechanical polishing approaches its endpoint, the friction between the polishing pad 104 and the wafer 108 begins to change, and the current of the servo motor driving the polishing head 106 to rotate changes to ensure that the rotation speed of the polishing head 106 remains constant. Therefore, monitoring the current of the servo motor can determine the endpoint of the chemical mechanical polishing. With this setting, polishing can be ended at the endpoint of the chemical mechanical polishing, reducing process costs and enabling the chemical mechanical planarization process to run automatically.

[0099] In one embodiment, the endpoint detection device 124 further includes a photoelectric detection device, which detects the film thickness of a preset thin film on the surface of the wafer 108 and generates a film thickness detection signal based on the film thickness; the control device 112 determines the endpoint of the chemical mechanical polishing based on the film thickness detection signal. The preset thin film is a film layer that needs to be chemically mechanically polished for chemical mechanical planarization.

[0100] This application also provides a detection device, including a controller, a memory, and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps of the method for adjusting chemimechanical planarization as described above.

[0101] It should be understood that, although Figure 5 , Figure 6 , Figure 7 The steps in the flowchart are shown sequentially as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order in which these steps are executed, and they can be performed in other orders. Figure 5 , Figure 6 , Figure 7At least some of the steps in the process may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be executed in turn or alternately with other steps or at least some of the sub-steps or stages of other steps.

[0102] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0103] The above-described embodiments are merely illustrative of several implementation methods of the present disclosure, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present disclosure embodiments, and these modifications and improvements all fall within the protection scope of the present disclosure embodiments.

Claims

1. A chemical mechanical grinding apparatus, characterized in that, include: Grinding disc, used to hold the polishing pad; A grinding head is located above the grinding disk, and the side of the grinding head closest to the grinding disk carries a wafer; The grinding head includes a base and a positioning ring located on a first surface of the base; the sidewall of the positioning ring and a portion of the first surface of the base are formed as the inner wall of a first groove, and the wafer is located in the first groove; The positioning ring has a first opening and a second opening on the side near the polishing pad; A first detection device is disposed on the outer side of the wafer and is used to detect the thickness change of the wafer and generate a thickness difference signal based on the thickness change. The first detection device is housed in the first opening; The second detection device is located on the outside of the wafer and is used to detect the wear amount of the polishing pad and generate a wear signal based on the wear amount. The second detection device is housed in the second opening; A control device, connected to the first detection device and the second detection device, is used to receive the thickness difference signal and the wear signal, and generate a control signal based on the thickness difference signal and the wear signal. The control signal is used to adjust the first gap between the polishing pad and the polishing head so that the polishing rate of the polishing pad polishing the wafer remains constant.

2. The chemical mechanical grinding apparatus according to claim 1, characterized in that, Also includes: A grinding disc drive device is connected to the control device and is used to adjust the first spacing according to the control signal.

3. The chemical mechanical grinding apparatus according to claim 1, characterized in that, Also includes: A pressure detection device is used to detect the polishing pressure between the polishing pad and the wafer, and to generate a pressure detection signal based on the polishing pressure; The control device is connected to the pressure detection device and is used to receive the pressure detection signal and generate a pressure adjustment signal based on the pressure detection signal and the thickness difference signal. The pressure adjustment signal is used to adjust the polishing pressure between the polishing pad and the wafer so that the polishing rate remains constant.

4. The chemical mechanical grinding apparatus according to claim 1, characterized in that, Also includes: A speed detection device is used to detect the rotational speed of the grinding head and generate a speed detection signal based on the rotational speed. The control device is connected to the speed detection device and is used to receive the speed detection signal and generate a speed adjustment signal based on the speed detection signal. The speed adjustment signal is used to adjust the rotation speed of the grinding head so that the grinding rate remains constant.

5. The chemical mechanical grinding apparatus according to claim 4, characterized in that, Also includes: A grinding head drive device, connected to the control device, is used to adjust the rotational speed of the grinding head according to the speed adjustment signal; It is also used to adjust the first spacing according to the control signal.

6. A method for adjusting chemical mechanical planarization, performed using the chemical mechanical grinding equipment according to any one of claims 1-5, characterized in that, A chemical mechanical polishing (CMP) apparatus is used to planarize the surface of a wafer. The CMP apparatus includes a polishing disc and a polishing head. The polishing disc supports a polishing pad, and the polishing head is positioned above the polishing disc. The wafer is supported on the side of the polishing head closest to the polishing disc. The method includes: The thickness change of the wafer is detected, and a thickness difference signal is generated based on the thickness change; And detect the wear amount of the polishing pad, and generate a wear signal based on the wear amount; A control signal is generated based on the thickness difference signal and the wear signal; The first gap between the polishing pad and the polishing head is adjusted according to the control signal so that the polishing rate of the polishing pad polishing the wafer remains constant.

7. The method according to claim 6, characterized in that, Also includes: The polishing pressure between the polishing pad and the wafer is detected, and a pressure detection signal is generated based on the polishing pressure. A pressure adjustment signal is generated based on the pressure detection signal and the thickness difference signal; The pressure between the polishing pad and the wafer is adjusted according to the pressure adjustment signal to keep the polishing rate constant.

8. The method according to claim 6, characterized in that, Also includes: The rotational speed of the grinding head is detected, and a speed detection signal is generated based on the rotational speed; A speed adjustment signal is generated based on the speed detection signal. The speed adjustment signal is used to adjust the rotation speed of the grinding head so that the grinding rate remains constant.

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