Chemical mechanical planarization method and chemical mechanical planarization device

Abstract

The invention relates to the technical field of semiconductor manufacturing, and discloses a chemical mechanical planarization method and a chemical mechanical planarization device.The chemical mechanical planarization method comprises the steps that a to-be-planarized structure is provided, the to-be-planarized structure comprises a substrate layer and a sacrificial layer, a groove is formed in the substrate layer, the sacrificial layer is located on the surface of one side of the substrate layer, and the sacrificial layer is located on the surface of the other side of the substrate layer; the sacrificial layer fills the groove; performing a chemical mechanical planarization step on the surface of one side, deviating from the substrate layer, of the sacrificial layer according to the first process parameter; performing a chemical mechanical planarization step on the surface of one side, deviating from the substrate layer, of the sacrificial layer according to a second process parameter; and when the thickness of any area of the sacrificial layer located on the substrate layer is reduced to zero, the polishing head sets the pressure value applied to the corresponding area of the sacrificial layer to be zero. And when the thickness of any area of the sacrificial layer located on the substrate layer is reduced to zero, the polishing head sets the pressure value applied to the corresponding area of the sacrificial layer to be zero, and the situation that the polishing head continues to polish the area is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor manufacturing, and in particular to a chemical mechanical planarization method and a chemical mechanical planarization device. Background Art

[0002] As the key dimensions of integrated circuit devices continue to shrink, the thickness of the polysilicon gate also continues to decrease with the shrinking of the dimensions. However, this also leads to a sharp increase in the leakage current of the polysilicon gate and the gradual depletion of polysilicon, which leads to a decrease in device reliability. Compared with the polysilicon gate, the metal gate has lower resistance and higher electron mobility, which helps to reduce the gate resistance and delay time, thereby improving the switching speed and performance of the device.

[0003] The preparation process of most metal gates is as follows: a metal layer is formed on the surface of the wafer, and the metal layer fills a groove with a high aspect ratio on the wafer. After the metal is filled, in order to avoid short circuits, excess and uneven metal is removed through a chemical mechanical planarization process, that is, it is necessary to remove the residual metal in other areas of the wafer surface except the groove. In related technologies, the residual metal is often removed by increasing the polishing time of chemical mechanical planarization. However, as the polishing time increases, the metal in the groove will be over-polished, resulting in depressions in the metal in the groove, which will ultimately affect the electrical reliability of the device. Summary of the invention

[0004] In view of this, the present invention provides a chemical mechanical planarization method to solve the existing problem that as the polishing time increases, the metal in the groove will be corroded by the grinding liquid, resulting in depressions in the metal in the groove, which will eventually affect the electrical reliability of the device.

[0005] In a first aspect, the present invention provides a chemical mechanical planarization method, comprising:

[0006] Providing a structure to be planarized, the structure to be planarized comprising a substrate layer and a sacrificial layer, the substrate layer is provided with a groove, the sacrificial layer is located on a side surface of the substrate layer, and the sacrificial layer fills the groove;

[0007] According to a first process parameter, a chemical mechanical planarization step is performed on a surface of the sacrificial layer facing away from the substrate layer, wherein the first process parameter includes: the hardness of a first polishing pad used in the chemical mechanical planarization step is a first preset value, a polishing head used in the chemical mechanical planarization step applies corresponding pressures to different regions of the sacrificial layer according to a first preset pressure value sequence, and the thickness of different regions of the sacrificial layer located on the substrate layer when the chemical mechanical planarization step is stopped is a second preset value;

[0008] According to a second process parameter, a chemical mechanical planarization step is performed on a surface of the sacrificial layer facing away from the substrate layer, wherein the second process parameter includes: the hardness of the second polishing pad used in the chemical mechanical planarization step is a third preset value, the polishing head used in the chemical mechanical planarization step applies corresponding pressures to different regions of the sacrificial layer according to a second preset pressure value sequence, and the thickness of different regions of the sacrificial layer on the substrate layer is zero when the chemical mechanical planarization step is stopped;

[0009] When the thickness of any region of the sacrificial layer located on the substrate layer is reduced to zero, the polishing head sets the pressure value applied to the corresponding region of the sacrificial layer to zero.

[0010] Beneficial effect: According to the first process parameter, a chemical mechanical planarization step is performed on the surface of the sacrificial layer facing away from the substrate layer to reduce the thickness of the sacrificial layer until the thickness of each region of the sacrificial layer on the substrate layer reaches a second preset value. The thickness of the sacrificial layer is greatly reduced through the above operation. Then, according to the second process parameter, a chemical mechanical planarization step is performed on the surface of the sacrificial layer facing away from the substrate layer to continue to reduce the thickness of the sacrificial layer until the thickness of different regions of the sacrificial layer on the substrate layer is zero. The sacrificial layer on the substrate layer is removed through the above operation. In this process, when the thickness of any region of the sacrificial layer on the substrate layer is reduced to zero, the polishing head sets the pressure value applied to the corresponding region of the sacrificial layer to zero, so as to prevent the polishing head from continuing to polish the region, thereby avoiding excessive polishing of the sacrificial layer in the groove, and further avoiding depression of the sacrificial layer in the groove, thereby improving the reliability of the final product.

[0011] In an optional embodiment, in the chemical mechanical planarization step, the thickness of each different area of ​​the sacrificial layer located on the substrate layer is obtained, and the polishing head adjusts the pressure applied to each different area of ​​the sacrificial layer according to the thickness of each different area of ​​the sacrificial layer.

[0012] In the chemical mechanical planarization step, the polishing head adjusts the pressure applied to different areas of the sacrificial layer according to the thickness of different areas of the sacrificial layer, thereby adjusting the polishing speed of different areas of the sacrificial layer, thereby avoiding large deviations in thickness between different areas of the sacrificial layer and improving the flatness of the polished surface of the sacrificial layer.

[0013] In an optional implementation, the third preset value is smaller than the first preset value.

[0014] The hardness of the second polishing pad is less than that of the first polishing pad, that is, the deformation capacity of the second polishing pad is greater than that of the first polishing pad, so that the first polishing pad is in full contact with the polishing surface of the sacrificial layer, thereby improving the removal rate of the sacrificial layer on the substrate layer and reducing the residual rate of the sacrificial layer on the substrate layer.

[0015] In an optional implementation, the first preset value is 50-70 HS (Shore hardness), and the third preset value is 5-20 HS (Shore hardness).

[0016] The first polishing pad uses a hardness within the first preset value range to improve the efficiency of reducing the thickness of the sacrificial layer, thereby reducing the polishing time and improving the polishing efficiency. The second polishing pad uses a hardness within the third preset value range to improve the residual rate of removing the sacrificial layer located on the substrate layer, thereby reducing the risk of short circuit and further improving the electrical reliability of the device.

[0017] In an optional implementation, an eddy current sensor is used to obtain the thickness of different regions of the sacrificial layer on the substrate layer.

[0018] The thickness of different areas of the sacrificial layer can be accurately obtained by using an eddy current sensor, and the installation of the eddy current sensor is simple and convenient, without the need for major modifications to the chemical mechanical planarization device.

[0019] In an optional implementation, the second preset value is 150A (angstrom).

[0020] When the second preset value is greater than 150A, the thickness of the sacrificial layer removed according to the second process parameter is too large, which causes the chemical mechanical planarization time to be too long, and further leads to low chemical mechanical polishing efficiency; when the second preset value is less than 150A, it is easy to cause the sacrificial layer in the groove to be over-polished according to the first process parameter, resulting in the formation of grooves, which ultimately affects the reliability of the device.

[0021] In an optional embodiment, the sacrificial layer is made of tungsten.

[0022] The present invention also provides a chemical mechanical planarization device, comprising:

[0023] A workbench having a first polishing area and a second polishing area arranged at intervals;

[0024] The hardness of the first polishing pad in the first polishing area is a first preset value;

[0025] The hardness of the second polishing pad in the second polishing area is a second preset value;

[0026] A polishing head module, comprising a rotary drive member and a polishing head, wherein the rotary drive member is mounted on the workbench and connected to the polishing head;

[0027] The rotary drive member can drive the polishing head to rotate, so that the polishing head is deflected from the first polishing area to the second polishing area, or the polishing head is deflected from the second polishing area to the first polishing area;

[0028] A first detection member connected to the workbench and used to obtain the thickness of different regions of the sacrificial layer in the structure to be planarized on the first polishing pad;

[0029] The second detection member is connected to the workbench and is used to obtain the thickness of different regions of the sacrificial layer in the structure to be planarized on the second polishing pad.

[0030] The chemical mechanical planarization device uses a first polishing pad to greatly reduce the thickness of a sacrificial layer on a substrate layer, and then uses a second polishing pad to remove the sacrificial layer on the substrate layer, and obtains the thickness of different regions of the sacrificial layer through a second detection element, thereby preventing the polishing head from continuing to over-polish different regions of the sacrificial layer, thereby avoiding excessive polishing of the sacrificial layer in the groove, and further avoiding depressions in the sacrificial layer in the groove, thereby improving the reliability of the final product.

[0031] In an optional implementation, it also includes:

[0032] Storage boxes;

[0033] A transfer module, wherein the workbench has a loading and unloading area, and the transfer module is used to transfer the structure to be flattened between the storage box and the loading and unloading area;

[0034] The polishing head is used to transfer the structure to be planarized between the loading and unloading area and the first polishing area or the second polishing area. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0036] Figure 1 is a flowchart of a chemical mechanical planarization method according to an embodiment of the present invention;

[0037] Figure 2is a cross-sectional view of a structure to be planarized according to an embodiment of the present invention;

[0038] Figure 3 is a schematic diagram of a chemical mechanical planarization device according to an embodiment of the present invention;

[0039] Figure 4 is a working principle diagram of the first polishing area in the chemical mechanical planarization device according to an embodiment of the present invention;

[0040] Figure 5 It is a schematic diagram showing that the metal layer in the groove will be over-polished in the related art.

[0041] 100, structure to be planarized; 101, substrate layer; 1010, groove; 102, sacrificial layer;

[0042] 201, workbench; 2011, first polishing area; 20111, polishing disc; 20112, first polishing pad; 20113, feedback module; 20114, motor; 20115, control module; 20116, bracket; 2012, second polishing area; 2013, loading and unloading area; 202, polishing head module; 2020, rotating driving member; 2021, polishing head; 203, first detection member; 204, storage box; 205, transmission module; 2050, manipulator;

[0043] 301. Wafer; 302. Metal layer. DETAILED DESCRIPTION

[0044] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It is understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only some structures related to the present invention are shown in the accompanying drawings, rather than all structures. In the following description, the description of known structures and technologies is omitted to avoid unnecessary confusion of the concept of the present invention. Various structural schematic diagrams according to embodiments of the present invention are shown in the accompanying drawings. These figures are not drawn to scale, and some details are magnified for the purpose of clear expression, and some details may be omitted. The shapes of various regions and layers shown in the figures and the relative sizes and positional relationships between them are only exemplary, and may be deviated due to manufacturing tolerances or technical limitations in practice, and those skilled in the art may additionally design regions / layers with different shapes, sizes, and relative positions according to actual needs. In the context of the present invention, when a layer / element is referred to as being "on" another layer / element, the layer / element may be directly on the other layer / element, or there may be an intermediate layer / element between them. In addition, if one layer / element is "on" another layer / element in one orientation, then when the orientation is reversed, the layer / element may be "below" the other layer / element.

[0045] In the preparation process of the metal gate, a metal layer 302 needs to be formed on one side of the wafer 301, and the metal layer 302 fills the groove with a high aspect ratio on the wafer 301. After the metal layer 302 is formed, in order to avoid short circuit, the redundant and uneven metal is removed by a chemical mechanical planarization process, that is, the residual metal in other areas outside the groove needs to be removed. In the related art, the polishing time of the chemical mechanical planarization is often increased to improve the removal rate of the residual metal. However, as the polishing time increases, Figure 5 As shown, the metal in the groove will be over-polished, resulting in depressions in the metal in the groove, which will eventually affect the electrical reliability of the device.

[0046] Therefore, an embodiment of the present invention provides a Huaye mechanical planarization method. When the thickness of any area of ​​the sacrificial layer 102 located on the substrate layer 101 is reduced to zero, the polishing head 2021 sets the pressure value applied to the corresponding area of ​​the sacrificial layer 102 to zero, so as to prevent the polishing head 2021 from continuing to polish the area, thereby avoiding excessive polishing of the sacrificial layer 102 in the groove.

[0047] In a first aspect, this embodiment provides a chemical mechanical planarization method, such as Figure 1 As shown, the following steps are included:

[0048] S100, such as Figure 2 As shown, a structure 100 to be planarized is provided, and the structure 100 to be planarized includes a substrate layer 101 and a sacrificial layer 102 . The substrate layer 101 has grooves with a high aspect ratio. The sacrificial layer 102 is located on one side surface of the substrate layer 101 , and the sacrificial layer 102 fills all the grooves.

[0049] Specifically, the material of the substrate layer 101 may be silicon, gallium arsenide, gallium nitride, silicon carbide or other semiconductor materials, and the material of the sacrificial layer 102 may be metal. Preferably, the material of the sacrificial layer 102 in the present application is tungsten. Filling the grooves with tungsten can improve the uniformity of filling, and tungsten has good electrical conductivity, high temperature stability, chemical stability and mechanical properties. The sacrificial layer 102 can be formed on one side of the substrate layer 101 by a vapor deposition process, and the sacrificial layer 102 fills all the grooves in the substrate layer 101.

[0050] S200, performing a chemical mechanical planarization step on a surface of the sacrificial layer 102 facing away from the substrate layer 101 according to a first process parameter, wherein the first process parameter includes: the hardness of the first polishing pad 20112 used in the chemical mechanical planarization step is a first preset value, the polishing head 2021 used in the chemical mechanical planarization step applies corresponding pressures to different regions of the sacrificial layer 102 according to a first preset pressure value sequence, and the thicknesses of different regions of the sacrificial layer 102 located on the substrate layer 101 when the chemical mechanical planarization step is stopped are all second preset values;

[0051] Specifically, a chemical mechanical planarization device is used to perform a first chemical mechanical planarization step on the surface of the sacrificial layer 102 facing away from the substrate layer 101, so as to significantly reduce the thickness of the sacrificial layer 102; the first preset value is adjusted according to the material of the sacrificial layer 102; the first preset pressure value sequence is the initial pressure applied by the polishing head 2021 to different areas of the sacrificial layer 102 in the first chemical mechanical planarization step.

[0052] S300, performing a chemical mechanical planarization step on a surface of the sacrificial layer 102 facing away from the substrate layer 101 according to a second process parameter, wherein the second process parameter includes: the hardness of the second polishing pad used in the chemical mechanical planarization step is a third preset value, the polishing head 2021 used in the chemical mechanical planarization step applies corresponding pressures to different regions of the sacrificial layer 102 according to a second preset pressure value sequence, and the thickness of different regions of the sacrificial layer 102 located on the substrate layer 101 is zero when the chemical mechanical planarization step stops. When the thickness of any region of the sacrificial layer 102 located on the substrate layer 101 is reduced to zero, the polishing head 2021 sets the pressure value applied to the corresponding region of the sacrificial layer 102 to zero.

[0053] Specifically, a second chemical mechanical planarization step is performed on the surface of the sacrificial layer 102 facing away from the substrate layer 101 using a chemical mechanical planarization device to remove the remaining sacrificial layer 102 on the substrate layer 101 and ensure that the sacrificial layer 102 in the groove does not appear concave. The third preset value can be adjusted according to the material of the sacrificial layer 102; the second preset pressure value sequence is the initial pressure applied by the polishing head 2021 to different regions of the sacrificial layer 102 in the second chemical mechanical planarization step.

[0054] The present embodiment provides a step of performing a chemical mechanical planarization on the surface of the sacrificial layer 102 facing away from the substrate layer 101 according to the first process parameters to reduce the thickness of the sacrificial layer 102 until the thickness of each region of the sacrificial layer 102 located on the substrate layer 101 reaches a second preset value. The above operation achieves a significant reduction in the thickness of the sacrificial layer 102. Then, according to the second process parameters, a chemical mechanical planarization step is performed on the surface of the sacrificial layer 102 facing away from the substrate layer 101 to continue reducing the thickness of the sacrificial layer 102 until the thickness of different regions of the sacrificial layer 102 located on the substrate layer 101 are zero. The above operation achieves the removal of the sacrificial layer 102 located on the substrate layer 101. During this process, when the thickness of any area of ​​the sacrificial layer 102 located on the substrate layer 101 is reduced to zero, the polishing head 2021 sets the pressure value applied to the corresponding area of ​​the sacrificial layer 102 to zero, so as to prevent the polishing head 2021 from continuing to polish the area, thereby avoiding excessive polishing of the sacrificial layer 102 in the groove, and further avoiding the occurrence of depressions in the sacrificial layer 102 in the groove 1010, thereby improving the reliability of the final product.

[0055] In this embodiment, as an optional implementation, in the chemical mechanical planarization step, the thickness of each different region of the sacrificial layer 102 located on the substrate layer 101 is obtained, and the polishing head 2021 adjusts the pressure applied to each different region of the sacrificial layer 102 according to the thickness of each different region of the sacrificial layer 102. In the chemical mechanical planarization step, the polishing head 2021 adjusts the pressure applied to each different region of the sacrificial layer 102 according to the thickness of each different region of the sacrificial layer 102, thereby adjusting the polishing speed of each different region of the sacrificial layer 102, thereby avoiding a large deviation between the thicknesses of each different region of the sacrificial layer 102, and improving the flatness of the polished surface of the sacrificial layer 102.

[0056] In this embodiment, as an optional implementation, the third preset value is less than the first preset value. Preferably, the first preset value is 50-70HS (Shore hardness), and the third preset value is 5-20HS (Shore hardness). The first polishing pad 20112 uses a hardness within the first preset value range, and can be matched with a corresponding polishing liquid to improve the efficiency of removing the sacrificial layer 102, thereby reducing the polishing time and improving the polishing efficiency. The second polishing pad uses a hardness within the third preset value range, which increases the deformation capacity of the second polishing pad, so that the first polishing pad 20112 is fully in contact with the polishing surface of the sacrificial layer 102, thereby improving the removal rate of the sacrificial layer 102 located on the substrate layer 101, thereby reducing the risk of short circuit, and thereby improving the electrical reliability of the device.

[0057] In this embodiment, as an optional implementation, an eddy current sensor is used to obtain the thickness of different regions of the sacrificial layer 102 located on the substrate layer 101. The thickness of each different region of the sacrificial layer 102 can be accurately obtained by the eddy current sensor, and the installation of the eddy current sensor is simple and convenient, and there is no need to make major modifications to the chemical mechanical planarization device.

[0058] In this embodiment, as an optional implementation, the second preset value is 150A (angstroms). When the second preset value is greater than 150A, the thickness of the sacrificial layer 102 removed according to the second process parameter is too large, which causes the chemical mechanical planarization time to be too long, and further leads to low chemical mechanical polishing efficiency; when the second preset value is less than 150A, it is easy to cause the sacrificial layer 102 in the groove to be over-polished according to the first process parameter, resulting in the formation of grooves, which ultimately affects the reliability of the device.

[0059] Example 1

[0060] The substrate layer 101 is a wafer 301, the material of the substrate layer 101 is silicon, the material of the sacrificial layer 102 is tungsten, the thickness of the sacrificial layer 102 on the substrate layer 101 is 2500A, and the sacrificial layer 102 is divided into five regions according to different radii. For example, region five is a circumferential surface with a radius of 0-40mm (millimeter), region four is a torus with a radius of 40-100mm, region three is a torus with a radius of 100-125mm, region two is a torus with a radius of 125-135mm, and region one is a torus with a radius of 135-150mm. In the first process parameter, the first preset value is 60HS, the second preset value is 150A, and the first preset pressure value sequence is shown in the following table:

[0061]

[0062] Psi is pounds-force per square inch, a unit of pressure measurement.

[0063] In the second process parameter, the third preset value is 14.8HS, and the second preset pressure value sequence is shown in the following table:

[0064]

[0065] In the second chemical mechanical polishing step, the polishing time is 80s (seconds), the rotation speed of the polishing disk 20111 is 93RPS (revolutions per second), the rotation speed of the polishing head 2021 is 87RPS, and the polishing liquid flow rate is 200ml / min (milliliters per minute).

[0066] After the chemical mechanical planarization method is used, the metal tungsten remaining near the groove on the substrate layer 101 is completely removed, and the thickness of the sacrificial layer 102 in the groove is less than 10 Å.

[0067] In a second aspect, this embodiment provides a chemical mechanical planarization device, such as Figure 3 and Figure 4 As shown, it includes a workbench 201, a polishing head module 202, a first detection member 203 and a second detection member. The workbench 201 has a first polishing area 2011 and a second polishing area 2012 arranged at intervals. The hardness of the first polishing pad 20112 in the first polishing area 2011 is a first preset value, and the hardness of the second polishing pad in the second polishing area 2012 is a second preset value. The polishing module includes a rotating drive member 2020 and a polishing head 2021. The rotating member is driven and installed on the workbench 201 and connected to the polishing head 2021. The rotating drive member 2020 can drive The movable polishing head 2021 rotates so that the polishing head 2021 is deflected from the first polishing area 2011 to the second polishing area 2012, or the polishing head 2021 is deflected from the second polishing area 2012 to the first polishing area 2011; the first detection component 203 is connected to the workbench 201, and is used to obtain the thickness of each different area of ​​the sacrificial layer 102 in the structure to be flattened 100 located on the first polishing pad 20112; the second detection component is connected to the workbench 201, and is used to obtain the thickness of each different area of ​​the sacrificial layer 102 in the structure to be flattened 100 located on the second polishing pad.

[0068] Specifically, the workbench 201 is used to perform a chemical mechanical planarization step. The workbench 201 also has a polishing liquid spray arm for spraying polishing liquid onto the first polishing pad 20112 or the second polishing pad. The polishing head module 202 also includes a support arm, and both ends of the support arm are respectively connected to the rotating drive member 2020 and the polishing head 2021. The rotating drive member 2020 is a motor 20114. The rotating drive member 2020 drives the support arm to rotate to drive the polishing head 2021 to rotate around the rotating drive member 2020, thereby causing the polishing head 2021 to deflect between the first polishing area 2011 and the second polishing area 2012. The first detection member 203 and the second detection member are both eddy current sensors.

[0069] In this embodiment, as an optional implementation, it also includes a storage box 204 and a transfer module 205. The storage box 204 is a front-opening wafer 301 transfer box (FOUP), and the storage box 204 is a container for protecting and storing the structure to be flattened 100; the transfer module 205 is an equipment front-end module (EFEM), which is an equipment front-end transfer system for transferring the structure to be flattened 100 to a desired position through a confidential robot 2050 in a high-clean environment. The workbench 201 has a loading and unloading area 2013 for storing the structure to be flattened 100 and the structure to be flattened 100 after the residual sacrificial layer 102 is removed. The transfer module 205 is used to transfer the structure to be flattened 100 between the loading and unloading area 2013 and the first polishing area 2011 or the second polishing area 2012.

[0070] In this embodiment, as an optional implementation, the first polishing area 2011 includes a polishing disc 20111, a first polishing pad 20112, a feedback module 20113, a motor 20114, a control module 20115 and a bracket 20116; the motor 20114 is connected to the polishing disc 20111 through a transmission shaft, the motor 20114 is used to drive the polishing disc 20111 to rotate, the polishing disc 20111 is provided with an installation cavity, the feedback module 20113 is arranged in the installation cavity, the feedback module 20113 is used to communicate with the first detection member 203, and is used to receive the electrical signal transmitted by the first detection member 203, the bracket 20116 116 is connected to the inner wall of the installation cavity, the first detection member 203 is installed on the bracket 20116, the detection end of the first detection member 203 faces the first polishing pad 20112, the first polishing pad 20112 is located on the top surface of the polishing disk 20111, the control module 20115 is a micro control unit, such as a computer or a central control computer, the control module 20115 is communicatively connected with the feedback module 20113, the control module 20115 is used to analyze the electrical signal transmitted by the first detection member 203 to draw a thickness variation diagram of different areas of the sacrificial layer 102; and according to the thickness variation diagram, to control the pressure applied by the polishing head 2021 to different areas of the sacrificial layer 102. The polishing head 2021 can absorb the structure 100 to be planarized, and the rotating driving member 2020 is also a motor 20114. Through the rotation of the driving member, the polishing head 2021 can transfer the structure 100 to be planarized in the loading and unloading area 2013 to the first polishing area 2011, and can also transfer the structure 100 to be planarized in the first polishing area 2011 to the second polishing area 2012, and can also transfer the structure 100 to be planarized in the second polishing area 2012 to the loading and unloading area 2013. The structure of the second polishing area 2012 is the same as that of the first polishing area 2011.

[0071] The working process of the chemical mechanical planarization device is:

[0072] First, the transfer module 205 transfers the structure to be flattened 100 in the storage box 204 to the loading and unloading area 2013 through its own manipulator 2050, and the rotary drive member 2020 rotates so that the polishing head 2021 is located directly above the loading and unloading area 2013, and the polishing head 2021 absorbs the structure to be flattened 100 in the loading and unloading area 2013, and then the rotary drive member 2020 rotates to drive the polishing head 2021 to rotate until the polishing head 2021 is transferred to directly above the first polishing pad 20112, and then the first chemical mechanical flattening step is performed according to the first process parameter until the thickness of each area of ​​the sacrificial layer 102 obtained by the first detection member 203 is the second preset value, and then the polishing head 2021 absorbs the structure to be flattened 100 on the first polishing pad 20112, and the rotary driving member 2020 rotates to deflect the polishing head 2021 to be directly above the second polishing pad, and then the first chemical mechanical flattening step is performed according to the first process parameters until the thickness of each area of ​​the sacrificial layer 102 obtained by the first detection member 203 is zero, and then the polishing head 2021 absorbs the structure to be flattened 100 on the second polishing pad, and the rotary driving member 2020 rotates to deflect the polishing head 2021 to be directly above the loading and unloading area 2013, and the transfer module 205 transfers the polished flattened structure in the loading and unloading area 2013 to another storage box 204 through the robot 2050.

[0073] In the above description, the technical details of the patterning and etching of each layer are not described in detail. However, those skilled in the art should understand that various technical means can be used to form layers, regions, etc. of desired shapes. In addition, in order to form the same structure, those skilled in the art can also design methods that are not completely the same as the methods described above. In addition, although the various embodiments are described above separately, this does not mean that the measures in the various embodiments cannot be used in combination to advantage.

[0074] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A chemical mechanical planarization method, characterized in that: include: A structure to be planarized (100) is provided, the structure to be planarized (100) comprising a substrate layer (101) and a sacrificial layer (102), a groove is provided on the substrate layer (101), the sacrificial layer (102) is located on a side surface of the substrate layer (101), and the sacrificial layer (102) fills the groove; According to a first process parameter, a chemical mechanical planarization step is performed on a surface of a side of the sacrificial layer (102) facing away from the substrate layer (101), wherein the first process parameter includes: the hardness of a first polishing pad (20112) used in the chemical mechanical planarization step is a first preset value, a polishing head (2021) used in the chemical mechanical planarization step applies corresponding pressures to different regions of the sacrificial layer (102) according to a first preset pressure value sequence, and the thickness of different regions of the sacrificial layer (102) located on the substrate layer (101) when the chemical mechanical planarization step is stopped is a second preset value; According to a second process parameter, a chemical mechanical planarization step is performed on a surface of a side of the sacrificial layer (102) facing away from the substrate layer (101), wherein the second process parameter includes: the hardness of the second polishing pad used in the chemical mechanical planarization step is a third preset value, the polishing head (2021) used in the chemical mechanical planarization step applies corresponding pressures to different regions of the sacrificial layer (102) according to a second preset pressure value sequence, and when the chemical mechanical planarization step is stopped, the thickness of different regions of the sacrificial layer (102) located on the substrate layer (101) are all zero; When the thickness of any region of the sacrificial layer (102) located on the substrate layer (101) is reduced to zero, the polishing head (2021) sets the pressure value applied to the corresponding region of the sacrificial layer (102) to zero.

2. The chemical mechanical planarization method according to claim 1, characterized in that: In the chemical mechanical planarization step, the thickness of each different area of ​​the sacrificial layer (102) located on the substrate layer (101) is obtained, and the polishing head (2021) adjusts the pressure applied to each different area of ​​the sacrificial layer (102) according to the thickness of each different area of ​​the sacrificial layer (102).

3. The chemical mechanical planarization method according to claim 1, characterized in that: The third preset value is smaller than the first preset value.

4. The chemical mechanical planarization method according to claim 3, characterized in that: The first preset value is 50-70 HS (Shore hardness), and the third preset value is 5-20 HS (Shore hardness).

5. The chemical mechanical planarization method according to claim 1, characterized in that: An eddy current sensor is used to obtain the thickness of different regions of the sacrificial layer (102) located on the substrate layer (101).

6. The chemical mechanical planarization method according to claim 1, characterized in that: The second preset value is 150A (angstrom).

7. The chemical mechanical planarization method according to claim 1, characterized in that: The sacrificial layer (102) is made of tungsten.

8. A chemical mechanical planarization device, characterized in that: include: A workbench (201) having a first polishing area (2011) and a second polishing area (2012) which are arranged at intervals; The hardness of the first polishing pad (20112) in the first polishing area (2011) is a first preset value; The hardness of the second polishing pad in the second polishing area (2012) is a second preset value; A polishing head module (202), comprising a rotating driving member (2020) and a polishing head (2021), wherein the rotating driving member (2020) is mounted on the workbench (201) and connected to the polishing head (2021); The rotating driving member (2020) is capable of driving the polishing head (2021) to rotate, so that the polishing head (2021) is deflected from the first polishing area (2011) to the second polishing area (2012), or the polishing head (2021) is deflected from the second polishing area (2012) to the first polishing area (2011); A first detection element (203) connected to the workbench (201) and used to obtain the thickness of different regions of the sacrificial layer (102) in the structure to be flattened (100) located on the first polishing pad (20112); The second detection element is connected to the workbench (201) and is used to obtain the thickness of different regions of the sacrificial layer (102) in the structure to be planarized (100) located on the second polishing pad.

9. The chemical mechanical planarization device according to claim 8, characterized in that: Also includes: Storage box (204); A transfer module (205), wherein the workbench (201) has a loading and unloading area (2013), and the transfer module (205) is used to transfer the structure to be flattened (100) between the storage box (204) and the loading and unloading area (2013); The polishing head (2021) is used to transfer the structure to be flattened (100) between the loading and unloading area (2013) and the first polishing area (2011) or the second polishing area (2012).

Images