CN111975469A - Chemical mechanical polishing method and polishing system - Google Patents

Chemical mechanical polishing method and polishing system Download PDF

Info

Publication number
CN111975469A
CN111975469A CN202010891822.9A CN202010891822A CN111975469A CN 111975469 A CN111975469 A CN 111975469A CN 202010891822 A CN202010891822 A CN 202010891822A CN 111975469 A CN111975469 A CN 111975469A
Authority
CN
China
Prior art keywords
polishing
film
thickness
grinding
area
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202010891822.9A
Other languages
Chinese (zh)
Inventor
同小刚
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Shanghai Huali Microelectronics Corp
Original Assignee
Shanghai Huali Microelectronics Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Shanghai Huali Microelectronics Corp filed Critical Shanghai Huali Microelectronics Corp
Priority to CN202010891822.9A priority Critical patent/CN111975469A/en
Publication of CN111975469A publication Critical patent/CN111975469A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
    • B24B1/00—Processes of grinding or polishing; Use of auxiliary equipment in connection with such processes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
    • B24B37/00—Lapping machines or devices; Accessories
    • B24B37/005—Control means for lapping machines or devices
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
    • B24B37/00—Lapping machines or devices; Accessories
    • B24B37/04—Lapping machines or devices; Accessories designed for working plane surfaces
    • B24B37/07—Lapping machines or devices; Accessories designed for working plane surfaces characterised by the movement of the work or lapping tool
    • B24B37/10—Lapping machines or devices; Accessories designed for working plane surfaces characterised by the movement of the work or lapping tool for single side lapping
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
    • B24B37/00—Lapping machines or devices; Accessories
    • B24B37/34—Accessories
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
    • B24B49/00—Measuring or gauging equipment for controlling the feed movement of the grinding tool or work; Arrangements of indicating or measuring equipment, e.g. for indicating the start of the grinding operation
    • B24B49/12—Measuring or gauging equipment for controlling the feed movement of the grinding tool or work; Arrangements of indicating or measuring equipment, e.g. for indicating the start of the grinding operation involving optical means

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Mechanical Treatment Of Semiconductor (AREA)

Abstract

The invention provides a chemical mechanical polishing method, which comprises the following steps: providing a polishing head having a plurality of polishing zones, the pressure applied by the polishing zones being independently controllable; and grinding a film by using the grinding head, detecting the thickness distribution of the film in real time in the grinding process, and adjusting the pressure applied to each grinding area in real time according to the thickness distribution of the film. The pressure applied by the grinding area acts on the back surface of the wafer, and the pressure applied by each grinding area of the grinding head on the back surface of the wafer is adjusted in real time according to the film thickness distribution by detecting the film thickness distribution on the surface of the wafer in real time. So that the thickness of each area of the film is relatively consistent in the grinding process, and the grinding flatness is improved. Correspondingly, the invention further provides a grinding system.

Description

Chemical mechanical polishing method and polishing system
Technical Field
The invention relates to the technical field of semiconductor manufacturing, in particular to a chemical mechanical polishing method and a polishing system.
Background
Chemical Mechanical Polishing (CMP) is a process in which a Chemical reaction process and a Mechanical Polishing process work together. Generally, the polishing head applies a certain pressure to the back surface of the wafer during the chemical mechanical polishing process to make the front surface of the wafer tightly contact with the polishing pad. Meanwhile, the grinding head rotates to drive the wafer and the grinding pad to rotate along different directions, so that the front surface of the wafer and the grinding pad generate mechanical friction. The thin film on the surface of the wafer is removed through a series of complicated mechanical and chemical actions in the grinding process, so that the purpose of flattening the surface of the wafer is achieved.
In the chemical mechanical polishing process, because the wafer has a large area and a small thickness, the wafer may be slightly deformed due to uneven pressure applied by the polishing head to the back surface of the wafer. Meanwhile, the non-uniformity of the polishing pad further causes excessive removal of part of the thin film on the wafer surface and insufficient removal of part of the thin film in the chemical mechanical polishing process, so that the wafer surface after the chemical mechanical polishing process is not flat, that is, the wafer surface has low flatness. As semiconductor manufacturing processes have been developed, the multi-metal layer stack has a higher requirement for the flatness of the wafer surface, and therefore, a method and a polishing system for improving the flatness of the cmp pad are sought.
Disclosure of Invention
The invention aims to provide a chemical mechanical polishing method and a polishing system, which can improve the flatness of the surface of a film after chemical mechanical polishing.
In order to achieve the above object, the present invention provides a chemical mechanical polishing method, comprising:
providing a polishing head having a plurality of polishing zones, the pressure applied by the polishing zones being independently controllable;
and grinding a film by using the grinding head, detecting the thickness distribution of the film in real time in the grinding process, and adjusting the pressure applied to each grinding area in real time according to the thickness distribution of the film.
Optionally, the step of adjusting the pressure applied to each grinding area in real time according to the thickness distribution of the thin film includes:
obtaining the average thickness of the thin film according to the thickness distribution of the thin film;
and increasing the pressure applied to the grinding area corresponding to the area of the film with the thickness larger than the average thickness, and reducing the pressure applied to the grinding area corresponding to the area of the film with the thickness smaller than the average thickness.
Optionally, the adjustment amount Z of the pressure applied to the grinding area corresponding to the area to be adjusted on the film satisfies the following formula:
Figure BDA0002655280370000021
wherein C is a constant determined based on the polishing conditions; zaPressure applied to the grinding zone corresponding to the central zone of the film, ZbFor the pressure in the area to be regulated on the membrane, SignalaThickness of the central region of the film, SignalbIs the thickness of the area to be adjusted on the film.
Optionally, the thicknesses of different areas on the thin film are detected in real time by using a plurality of detection units, so as to obtain the thickness distribution of the thin film.
Optionally, the detection unit comprises an optical endpoint detection device.
Optionally, the plurality of polishing regions include a circular first polishing region and a plurality of second polishing regions, and the second polishing regions surround the first polishing region and are in a concentric ring shape.
Optionally, the polishing head includes a circular first polishing region and a plurality of polishing region groups, the polishing region groups surround the first polishing region and are in a concentric ring shape, and each polishing region group includes a plurality of second polishing regions distributed circumferentially.
A polishing system for polishing a film, comprising:
a polishing head having a plurality of polishing zones, the pressure applied by the polishing zones being independently controllable;
the detection module is used for detecting the thickness distribution of the film in real time in the grinding process;
and the control module is used for adjusting the pressure applied by each grinding area in real time according to the thickness distribution of the film.
Optionally, the detection module includes at least two detection units.
Optionally, the control module includes:
a thickness calculation unit for calculating an average thickness of the thin film according to the thickness distribution of the thin film;
and the adjusting unit is used for increasing the pressure applied to the grinding area corresponding to the area, with the thickness being larger than the average thickness, of the thin film and reducing the pressure applied to the grinding area corresponding to the area, with the thickness being smaller than the average thickness, of the thin film.
Optionally, the control module further includes a pressure calculating unit, and the pressure calculating unit is configured to calculate an adjustment amount Z of pressure applied to a polishing area corresponding to an area to be adjusted on the thin film according to the following formula:
Figure BDA0002655280370000031
wherein C is a constant determined based on the polishing conditions; zaPressure applied to the grinding zone corresponding to the central zone of the film, ZbFor the pressure in the area to be regulated on the membrane, SignalaThickness of the central region of the film, SignalbIs the thickness of the area to be adjusted on the film.
The invention provides a chemical mechanical polishing method, which comprises the following steps: providing a polishing head having a plurality of polishing zones, the pressure applied by the polishing zones being independently controllable; and grinding a film by using the grinding head, detecting the thickness distribution of the film in real time in the grinding process, and adjusting the pressure applied to each grinding area in real time according to the thickness distribution of the film. The pressure applied by the grinding area acts on the film, and the pressure applied by each grinding area of the grinding head on the film is adjusted in real time by detecting the thickness distribution of the film in real time. Therefore, the thickness of each area of the film is relatively consistent in the mechanical chemical polishing process of the film, so that the flatness of the chemical mechanical polishing is improved. Correspondingly, the invention also provides a grinding system for grinding the film, which comprises a grinding head, a detection module and a control module. The polishing head has a plurality of polishing zones, the pressure applied by the polishing zones being independently controllable. The detection module is used for detecting the thickness distribution of the film in real time in the grinding process. The control module is used for adjusting the pressure applied by each grinding area in real time according to the thickness distribution of the thin film.
The detection module comprises at least two detection units, and the at least two detection units can simultaneously detect the film thickness of a plurality of areas on the surface of the wafer, so that the detection of the film thickness is more real-time.
Drawings
FIG. 1 is a schematic diagram of a polishing system;
FIG. 2 is a flow chart of a method of chemical mechanical polishing in an embodiment of the present invention;
FIG. 3 is a distribution diagram of a polishing zone in an embodiment of the present invention;
FIG. 4 is a distribution diagram of another polishing zone in an embodiment of the present invention;
FIG. 5 is a schematic view of a polishing system in an embodiment of the present invention;
FIG. 6 is a top view of a polishing system in an embodiment of the invention;
wherein the reference numbers are as follows:
100-grinding head; 110-a grinding zone; 111-a first abrasive region; 112-a second abrasive region; 200-a wafer; 300-a polishing pad; 310-a through hole; 400-grinding disc; 410-a detection unit; 411-the transmitting end; 412-the receiving end.
Detailed Description
The following describes in more detail embodiments of the present invention with reference to the schematic drawings. The advantages and features of the present invention will become more apparent from the following description. It is to be noted that the drawings are in a very simplified form and are not to precise scale, which is merely for the purpose of facilitating and distinctly claiming the embodiments of the present invention.
Fig. 1 is a schematic structural diagram of a polishing system, as shown in fig. 1, including a polishing disc 400, a polishing pad 300 and a polishing head 100. In the chemical mechanical polishing process, after the wafer 200 is first turned over by 180 degrees, the polishing head 100 is used to adsorb the back surface of the wafer 200, then the wafer 200 is pressed against the polishing pad 300 full of the ultrafine solid particle polishing particles and the chemical catalyst in a manner that the front surface of the wafer 200 faces downward, and then the ultrafine solid particle polishing particles are forced to polish the protruded points on the surface of the wafer 200 by using the relative motion between the polishing pad 300 and the polishing head 100, i.e. the difference of the linear velocities between the two, so as to achieve the purpose of flattening the surface of the wafer 200. The addition of the polishing slurry is one of the key elements of the chemical mechanical polishing process, and the polishing slurry directly affects the quality of the polished surface of the wafer 200, such as thickness, flatness and defect level. The components of the grinding fluid mainly comprise superfine solid particle grinding particles, an oxidizing agent, a surfactant, a stabilizer and the like. The polishing particles of the ultrafine solid particles in the polishing slurry provide friction to polish the surface of the wafer 200, and the chemical catalyst such as the oxidant and the like chemically reacts with the related material on the surface of the wafer 200, so that the thin film on the surface of the wafer 200 is softened and easily removed under the physical action.
The polishing pad 300 is a key component for conveying polishing liquid, and the polishing pad 300 is detachably disposed on the upper surface of the polishing disc 400 and is driven by the rotation of the polishing disc 400. The surface of the polishing pad 300 has a layer of porous polymer material, which is generally selected from Polyurethane (PU) and Polycarbonate (PC), etc., and the porous structure of the polishing pad 300 serves to store the polishing slurry. Meanwhile, the contact area between the film on the surface of the wafer 200 and the grinding fluid is increased, and the reaction speed is improved.
Based on this, the chemical mechanical polishing method of the present invention will be described in detail below with reference to the accompanying drawings.
Fig. 2 is a flowchart illustrating a method of chemical mechanical polishing according to an embodiment of the present invention, as shown in fig. 2, the method of chemical mechanical polishing includes the following steps:
step S1: providing a polishing head 100 having a plurality of polishing zones, wherein the pressure applied by the polishing zones can be independently controlled;
step S2: a film is polished by the polishing head 100, the thickness distribution of the film is detected in real time during the polishing process, and the pressure applied to each polishing area is adjusted in real time according to the thickness distribution of the film.
Referring to fig. 1 and 2, in the chemical mechanical polishing method of the present invention, the pressure applied to the polishing area acts on the back surface of the wafer 200, and the pressure applied to the back surface of the wafer 200 by each polishing area of the polishing head 100 is adjusted in real time according to the film thickness distribution by detecting the film thickness distribution on the surface of the wafer 200 in real time. In the area where the thickness of the thin film on the surface of the wafer 200 is too thick, the pressure of the polishing head 100 in the corresponding polishing area is increased. In the area where the thickness of the thin film on the surface of the wafer 200 is too thin, the pressure of the polishing head 100 in the corresponding polishing area is reduced. In the process of mechanical chemical polishing, the film thickness of each region on the surface of the wafer 200 is relatively uniform, so as to improve the flatness of chemical mechanical polishing.
Further, in step S2, the step of adjusting the pressure applied by each of the polishing regions 110 in real time according to the thickness distribution of the thin film comprises:
obtaining the average thickness of the thin film according to the thickness distribution of the thin film;
and increasing the pressure applied to the grinding area corresponding to the area of the film with the thickness larger than the average thickness, and reducing the pressure applied to the grinding area corresponding to the area of the film with the thickness smaller than the average thickness.
Fig. 3 is a distribution diagram of a polishing region 110 according to an embodiment of the present invention, as shown in fig. 3, the polishing regions 110 include a circular first polishing region 111 and a plurality of second polishing regions 112, and the second polishing regions 112 surround the first polishing region 111 and are in concentric rings. The circular first polishing region 111 is located at the center of the polishing head 100, and the first polishing region 111 corresponds to the center region of the thin film.
Fig. 4 is a distribution diagram of another polishing region 110 according to an embodiment of the present invention, as shown in fig. 4, the polishing head includes a circular first polishing region 111 and a plurality of polishing region groups, the polishing region groups surround the first polishing region 111 and are in concentric rings, and each polishing region group includes a plurality of circumferentially distributed second polishing regions 112.
Optionally, the second polishing region 112 is of a uniform size in order to allow for more convenient adjustment of the pressure of the polishing region 110.
In step S1, independently controlling the pressure of the polishing regions 110 is achieved by controlling the pressure of the gas that is passed into the polishing regions 110. The pressure supply unit, which may be an air compressor, supplies air to the polishing regions 110, and after compressed air generated by the air compressor is introduced into each of the polishing regions 110 of the polishing head 100 through a plurality of air pipes. The air flow of each air pipe is controlled by a throttle valve to control the pressure of each corresponding grinding area 110. The portion of the polishing region 110 facing the wafer 200 is an elastic adhesive film, which deforms under the pressure inside the polishing region 110, so as to transmit the pressure of the polishing region 110 to the back surface of the wafer 200, and further to make the surface of the wafer 200 have pressure on the polishing pad 300.
In detail, the compressed air is respectively introduced into the independent second polishing regions 112, the sizes of the independent second polishing regions 112 are the same, and further the volumes inside the second polishing regions 112 can be the same, on the premise, when the gas flow rate of the gas input into each independent second polishing region 112 is constant, the internal pressures of the independent second polishing regions 112 are the same, the gas flow rate and the pressure of the second polishing region 112 are in a positive correlation, and the relationship curves of the gas flow rate-pressure curves of the independent second polishing regions 112 are the same. When the pressure of a polishing region 110 needs to be adjusted, the flow rate of the gas to be supplied to each of the independent second polishing regions 112 only needs to be adjusted, and the flow rate of the gas for adjusting the pressure may be determined according to the relationship curve of the flow rate-pressure curve of the gas.
Referring to fig. 1 and 3, the polishing head 100 and the polishing pad 300 are disposed facing each other, and the polishing head 100 is approximately a reversed disk, so that a space for accommodating the wafer 200 is formed between the polishing head 100 and the polishing pad 300. The polishing head 100 has a polishing region 110 having a pressure and capable of independently controlling the pressure, the polishing region 110 is bonded to the back surface of the wafer 200, and the pressure applied to the back surface of the wafer 200 in a region corresponding to the polishing region 110 can be adjusted by adjusting the pressure applied to the polishing region 110 of the polishing head 100, and the pressure applied to the back surface of the wafer 200 is also referred to as a polishing pressure.
The polishing head 100 rotates to drive the wafer 200 to rotate, and the rotation directions of the wafer 200 and the polishing pad 300 are different. Generally, the wafer 200 is uniformly polished in a state where the relative velocity between the wafer 200 and the polishing pad 300, the polishing pressure, and the supply of the polishing liquid are stable. And the film removal polishing rate of the surface of the wafer 200 is approximately proportional to the relative rate and the polishing pressure. In chemical mechanical polishing, the removal rate can be calculated by applying the following formula:
RR＝N×P×V；
wherein RR in the formula is the film removal polishing rate of the surface of the wafer 200, N is a constant determined based on the polishing conditions, P is the polishing pressure applied per unit area, and V is the relative velocity between the wafer 200 and the polishing pad 300.
From the above formula, the polishing pressure and the relative velocity between the wafer 200 and the polishing pad 300 are the main factors that determine the film removal rate of the surface of the wafer 200.
Based on this, we can adjust the pressure applied by the polishing area 110 to adjust the pressure of the stressed area on the surface of the wafer 200, and then control the de-polishing rate of the film on the surface of the wafer 200.
Fig. 5 is a schematic view of a polishing system according to an embodiment of the present invention, and as shown in fig. 5, the polishing system further includes a detection unit 410, wherein the detection unit 410 is disposed on the polishing platen 400 and is configured to detect a film thickness of the surface of the wafer 200 in the polishing region 110 in real time.
The detection unit 410 the detection unit comprises an optical endpoint detection device. The optical endpoint detection apparatus detects the film thickness on the surface of the wafer 200 by an optical-based method.
With continued reference to fig. 5, the detection unit 410 includes a transmitting end 411, a receiving end 412, and a detector. The detection unit 410 is used for detection using the principle of the optical reflectometry, which is the most widely used reflectometry, a typical optical endpoint detection device designed by applied materials, usa. In this system, the detecting unit 410 is disposed inside the upper surface of the polishing disc 400, the polishing pad 300 is laid on the upper surface of the polishing disc 400, the polishing pad 300 has a through hole 310, and the polishing head 100 drives the wafer 200 to rotate on the polishing pad 300. Through the reasonable setting of the rotation speed of the polishing disc 400 and the polishing head 100 and the left-right movement speed of the polishing head 100 relative to the polishing table, the light generated by the light source of the detection unit 410 can be irradiated to the surface of the whole wafer 200 through the through hole 310 on the polishing pad 300, thereby achieving the process of detecting the thickness variation of the whole wafer 200.
The detecting unit 410 is disposed inside the polishing disc 400, during the mechanochemical polishing process, light emitted from the emitting end 411 is transmitted to the through hole 310 of the polishing pad 300 through an optical fiber, the light irradiates the surface of the wafer 200 through the through hole 310, is reflected by the surface of the wafer 200, the reflected light passes through the through hole 310 of the polishing pad 300, is received by the receiving end 412, is transmitted to the receiving end 412 through another optical fiber, and the two beams of light are compared in the detector, so as to obtain the thickness value of the surface material of the wafer 200 in real time. When the thickness value reaches the grinding end value, the end point detection system sends a grinding stop signal to the host machine table to stop grinding the wafer 200, so that the thickness of the wafer 200 is accurately controlled.
The signal fed back by the detector of the detecting unit 410 is an analog type, and the digital-analog conversion is performed after the signal amplification, so as to obtain the numerical value of the film thickness on the surface of the wafer 200. Alternatively, the Signal (Signal) fed back from the detector of the detecting unit 410 can be used to directly characterize the film thickness on the surface of the wafer 200.
Optionally, the adjustment amount Z of the pressure applied to the polishing area 110 corresponding to the area to be adjusted on the film satisfies the following formula:
Figure BDA0002655280370000081
wherein C is a constant determined based on the polishing conditions; zaPressure, Z, applied to the polishing zone 110 corresponding to the central zone of the filmbFor the pressure in the area to be regulated on the membrane, SignalaThickness of the central region of the film, SignalbIs the thickness of the area to be adjusted on the film.
The polishing region 110 corresponding to the central region of the thin film is the first polishing region 111, and the above formula shows that when the polishing head 100 applies the pressure (i.e. Z) to the first polishing region 111aThe digital value of (1) is a constant value, the digital value of the film thickness of the first polishing area 111 of the polishing head 100 fed back by the detector and the digital value of the film thickness of the area to be adjusted can calculate the adjustment amount Z of the pressure applied to the polishing area 110 corresponding to the area to be adjusted.
C is a constant determined based on polishing conditions including the type of thin film to be polished, the type of polishing pad used, and the type of polishing apparatus used. It will be appreciated that the value of C can be adjusted according to experience of the person skilled in the art.
Optionally, the thicknesses of different areas on the thin film are detected in real time by using a plurality of detection units 410, so as to obtain the thickness distribution of the thin film. The surface of the wafer 200 of the polishing area 110 is detected in real time by the detecting units 410, and the film thickness of the polishing area 110 corresponding to the surface of the wafer 200 is fed back in real time, so as to adjust the pressure applied by the corresponding polishing area 110.
Fig. 6 is a top view of a polishing system according to an embodiment of the invention, as shown in fig. 6, a plurality of detecting units 410 are disposed in a polishing platen 400, a plurality of through holes 310 are formed in a polishing pad 300, each through hole 310 corresponds to one detecting unit 410, the plurality of detecting units 410 can simultaneously detect the film thicknesses of a plurality of areas on the surface of a wafer 200 and simultaneously adjust the pressure of a polishing area 110 corresponding to the through hole, and the plurality of detecting units 410 can simultaneously detect the film thicknesses of a plurality of areas on the surface of the wafer 200, compared to a method in which one detecting unit 410 is disposed on the polishing platen 400 to obtain the film thicknesses of a plurality of areas on the surface of the wafer 200, the detection of the film thicknesses has more real-time performance, and can more rapidly feed back the thickness of the surface of the wafer 200, and reduce measurement errors caused by time delay.
In addition, the invention also provides a grinding system, and the thin film on the surface of the wafer 200 is ground by the grinding system.
A polishing system for polishing a film, comprising:
a polishing head 100, said polishing head 100 having a plurality of polishing regions 110, the pressure applied by said polishing regions 110 being independently controllable;
the detection module is used for detecting the thickness distribution of the film in real time in the grinding process;
and the control module is used for adjusting the pressure applied by each grinding area 110 in real time according to the thickness distribution of the film.
The polishing head 100 and the polishing pad 300 are disposed facing each other, and a receiving space for receiving the wafer 200 is formed between the polishing head 100 and the polishing pad 300, the polishing head 100 rotates to drive the wafer 200 to rotate, and the rotation directions of the wafer 200 and the polishing pad 300 are different.
The polishing regions 110 of the polishing head 100 include a circular first polishing region 111 and a plurality of second polishing regions 112, and the second polishing regions 112 surround the first polishing region 111 and are in concentric rings.
It should be appreciated that the plurality of polishing regions 110 of the polishing head 100 may also be distributed as follows: the polishing head 100 includes a circular first polishing region 111 and a plurality of polishing region groups, the polishing region groups surround the first polishing region 111 and are in a concentric ring shape, and each polishing region group includes a plurality of second polishing regions 112 distributed circumferentially.
The function of the detection module of the polishing system is realized based on the detection unit 410, and the detection unit 410 is used for detecting the film thickness of the surface of the wafer 200 in the polishing area 110 in real time.
Optionally, the detection module includes at least two detection units 410. The plurality of inspection units 410 may simultaneously inspect the film thickness of a plurality of regions on the surface of the wafer 200.
Further, the control module includes:
a thickness calculation unit for calculating an average thickness of the thin film according to the thickness distribution of the thin film;
and the adjusting unit is used for increasing the pressure applied by the grinding area 110 corresponding to the area, with the thickness being larger than the average thickness, of the thin film and reducing the pressure applied by the grinding area 110 corresponding to the area, with the thickness being smaller than the average thickness, of the thin film.
Further, the control module further comprises a pressure calculating unit, wherein the pressure calculating unit is used for calculating the adjustment amount Z of the pressure applied to the grinding area 110 corresponding to the area to be adjusted on the film according to the following formula:
Figure BDA0002655280370000101
wherein C is a constant determined based on the polishing conditions; zaPressure, Z, applied to the polishing zone 110 corresponding to the central zone of the filmbFor the pressure in the area to be regulated on the membrane, SignalaThickness of the central region of the film, SignalbIs the thickness of the area to be adjusted on the film.
In summary, the present invention provides a chemical mechanical polishing method, which includes the following steps: providing a polishing head having a plurality of polishing zones, the pressure applied by the polishing zones being independently controllable; and grinding a film by using the grinding head, detecting the thickness distribution of the film in real time in the grinding process, and adjusting the pressure applied to each grinding area in real time according to the thickness distribution of the film. The pressure applied by the grinding area acts on the back surface of the wafer, and the pressure applied by each grinding area of the grinding head on the back surface of the wafer is adjusted in real time according to the film thickness distribution by detecting the film thickness distribution on the surface of the wafer in real time. And increasing the pressure of the corresponding grinding area on the grinding head in the area with thicker film on the surface of the wafer. And reducing the pressure of the corresponding grinding area on the grinding head in the area with the thinner film thickness on the surface of the wafer. In the process of mechanical chemical polishing, the film thickness of each area on the surface of the wafer is relatively consistent, so as to improve the flatness of the chemical mechanical polishing. Correspondingly, the invention also provides a grinding system for grinding the film, which comprises a grinding head, a detection module and a control module. The polishing head has a plurality of polishing zones, the pressure applied by the polishing zones being independently controllable. The detection module is used for detecting the thickness distribution of the film in real time in the grinding process. The control module is used for adjusting the pressure applied by each grinding area in real time according to the thickness distribution of the thin film. The detection module comprises at least two detection units, and the at least two detection units can detect the film thickness of a plurality of areas on the surface of the wafer simultaneously.
The above description is only a preferred embodiment of the present invention, and does not limit the present invention in any way. It will be understood by those skilled in the art that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (11)

1. A method of chemical mechanical polishing, comprising:
providing a polishing head having a plurality of polishing zones, the pressure applied by the polishing zones being independently controllable;
and grinding a film by using the grinding head, detecting the thickness distribution of the film in real time in the grinding process, and adjusting the pressure applied to each grinding area in real time according to the thickness distribution of the film.
2. The method of claim 1, wherein the step of adjusting the pressure applied by each polishing region in real time according to the thickness profile of the thin film comprises:
obtaining the average thickness of the thin film according to the thickness distribution of the thin film;
and increasing the pressure applied to the grinding area corresponding to the area of the film with the thickness larger than the average thickness, and reducing the pressure applied to the grinding area corresponding to the area of the film with the thickness smaller than the average thickness.
3. The chemical mechanical polishing method of claim 2, wherein the adjustment amount Z of the pressure applied to the polishing region corresponding to the region to be adjusted on the thin film satisfies the following formula:
Figure RE-FDA0002693868840000011
wherein C is a constant determined based on the polishing conditions; zaPressure applied to the grinding zone corresponding to the central zone of the film, ZbFor the pressure in the area to be regulated on the membrane, SignalaThickness of the central region of the film, SignalbIs the thickness of the area to be adjusted on the film.
4. The method of claim 1, wherein the thickness of different regions of the thin film is detected in real time by a plurality of detection units to obtain the thickness distribution of the thin film.
5. The method of claim 4, wherein the detection unit comprises an optical endpoint detector.
6. The method of claim 1, wherein the polishing regions comprise a circular first polishing region and a plurality of second polishing regions, the second polishing regions surrounding the first polishing region and being concentric rings.
7. The method of claim 1, wherein the polishing head comprises a circular first polishing region and a plurality of polishing region groups, the polishing region groups surrounding the first polishing region and being in concentric rings, each polishing region group comprising a plurality of circumferentially distributed second polishing regions.
8. A polishing system for polishing a film, comprising:
a polishing head having a plurality of polishing zones, the pressure applied by the polishing zones being independently controllable;
the detection module is used for detecting the thickness distribution of the film in real time in the grinding process;
and the control module is used for adjusting the pressure applied by each grinding area in real time according to the thickness distribution of the film.
9. The polishing system of claim 8, wherein the detection module includes at least two detection units.
10. The grinding system of claim 8, wherein the control module comprises:
a thickness calculation unit for calculating an average thickness of the thin film according to the thickness distribution of the thin film;
and the adjusting unit is used for increasing the pressure applied to the grinding area corresponding to the area, with the thickness being larger than the average thickness, of the thin film and reducing the pressure applied to the grinding area corresponding to the area, with the thickness being smaller than the average thickness, of the thin film.
11. The polishing system of claim 8, wherein the control module further comprises a pressure calculation unit for calculating an adjustment amount Z of pressure applied to the polishing area corresponding to the area to be adjusted on the thin film according to the following formula:
Figure RE-FDA0002693868840000021
wherein C is a constant determined based on the polishing conditions; zaPressure applied to the grinding zone corresponding to the central zone of the film, ZbFor the pressure in the area to be regulated on the membrane, SignalaThickness of the central region of the film, SignalbIs the thickness of the area to be adjusted on the film.
CN202010891822.9A 2020-08-28 2020-08-28 Chemical mechanical polishing method and polishing system Pending CN111975469A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202010891822.9A CN111975469A (en) 2020-08-28 2020-08-28 Chemical mechanical polishing method and polishing system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202010891822.9A CN111975469A (en) 2020-08-28 2020-08-28 Chemical mechanical polishing method and polishing system

Publications (1)

Publication Number Publication Date
CN111975469A true CN111975469A (en) 2020-11-24

Family

ID=73441075

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202010891822.9A Pending CN111975469A (en) 2020-08-28 2020-08-28 Chemical mechanical polishing method and polishing system

Country Status (1)

Country Link
CN (1) CN111975469A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113084692A (en) * 2021-04-27 2021-07-09 上海芯物科技有限公司 Chemical mechanical polishing method and chemical mechanical polishing apparatus
CN113400195A (en) * 2021-07-21 2021-09-17 北京烁科精微电子装备有限公司 Method and system for online partition adjustment of loading and unloading pressure of polishing head
CN114952595A (en) * 2022-06-21 2022-08-30 长鑫存储技术有限公司 Flatness control method, device, equipment and medium
CN117140340A (en) * 2023-10-27 2023-12-01 迈为技术(珠海)有限公司 Wafer grinding control method, device, equipment and medium

Citations (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
TW462907B (en) * 1999-07-09 2001-11-11 Applied Materials Inc Closed-loop control of wafer polishing in a chemical mechanical polishing system
US20050239222A1 (en) * 2004-04-23 2005-10-27 Hitachi Global Technologies Netherlands, B.V. Run-to-run control of backside pressure for CMP radial uniformity optimization based on center-to-edge model
CN102294646A (en) * 2010-06-23 2011-12-28 中芯国际集成电路制造(上海)有限公司 Grinding head and chemical mechanical grinding machine
US20120122373A1 (en) * 2010-11-15 2012-05-17 Stmicroelectronics, Inc. Precise real time and position low pressure control of chemical mechanical polish (cmp) head
US20120276820A1 (en) * 2011-04-29 2012-11-01 Shanghai Huali Microelectronics Corporation Method for Adjusting Metal Polishing Rate and Reducing Defects Arisen in a Polishing Process
CN102909651A (en) * 2012-10-12 2013-02-06 上海华力微电子有限公司 Polishing head for chemical polishing device and chemical polishing device with polishing head
CN104827383A (en) * 2014-02-08 2015-08-12 中芯国际集成电路制造(上海)有限公司 Chemical mechanical grinding device and chemical mechanical grinding method
CN105097434A (en) * 2014-05-21 2015-11-25 中国科学院微电子研究所 Flattening process
US20160059377A1 (en) * 2014-06-27 2016-03-03 Applied Materials, Inc. Configurable pressure design for multizone chemical mechanical planarization polishing head
CN106378698A (en) * 2016-10-27 2017-02-08 上海华力微电子有限公司 Grinding pressure compensation method for chemical mechanical grinding machine
CN106463384A (en) * 2014-07-18 2017-02-22 应用材料公司 Modifying substrate thickness profiles
CN107214610A (en) * 2017-05-05 2017-09-29 天津华海清科机电科技有限公司 The online flatness control system of copper CMP
CN107344327A (en) * 2017-05-05 2017-11-14 清华大学 In the method for improved wire flatness of wafer surface
CN107414664A (en) * 2016-05-23 2017-12-01 中芯国际集成电路制造(上海)有限公司 A kind of method of chemical-mechanical grinding device and cmp
WO2018037878A1 (en) * 2016-08-24 2018-03-01 信越半導体株式会社 Polishing apparatus and wafer polishing method
CN107984374A (en) * 2017-11-30 2018-05-04 上海华力微电子有限公司 A kind of detecting real-time device and its method for detecting for chemically-mechanicapolish polishing grinding rate
CN108908063A (en) * 2018-07-20 2018-11-30 清华大学 The control method and control system of polish pressure are adjusted according to consumptive material life cycle
CN109531404A (en) * 2018-11-30 2019-03-29 上海华力微电子有限公司 A kind of grinding system and grinding method for chemical mechanical grinding

Patent Citations (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
TW462907B (en) * 1999-07-09 2001-11-11 Applied Materials Inc Closed-loop control of wafer polishing in a chemical mechanical polishing system
US20050239222A1 (en) * 2004-04-23 2005-10-27 Hitachi Global Technologies Netherlands, B.V. Run-to-run control of backside pressure for CMP radial uniformity optimization based on center-to-edge model
CN102294646A (en) * 2010-06-23 2011-12-28 中芯国际集成电路制造(上海)有限公司 Grinding head and chemical mechanical grinding machine
US20120122373A1 (en) * 2010-11-15 2012-05-17 Stmicroelectronics, Inc. Precise real time and position low pressure control of chemical mechanical polish (cmp) head
US20120276820A1 (en) * 2011-04-29 2012-11-01 Shanghai Huali Microelectronics Corporation Method for Adjusting Metal Polishing Rate and Reducing Defects Arisen in a Polishing Process
CN102909651A (en) * 2012-10-12 2013-02-06 上海华力微电子有限公司 Polishing head for chemical polishing device and chemical polishing device with polishing head
CN104827383A (en) * 2014-02-08 2015-08-12 中芯国际集成电路制造(上海)有限公司 Chemical mechanical grinding device and chemical mechanical grinding method
CN105097434A (en) * 2014-05-21 2015-11-25 中国科学院微电子研究所 Flattening process
US20160059377A1 (en) * 2014-06-27 2016-03-03 Applied Materials, Inc. Configurable pressure design for multizone chemical mechanical planarization polishing head
CN106463384A (en) * 2014-07-18 2017-02-22 应用材料公司 Modifying substrate thickness profiles
CN107414664A (en) * 2016-05-23 2017-12-01 中芯国际集成电路制造(上海)有限公司 A kind of method of chemical-mechanical grinding device and cmp
WO2018037878A1 (en) * 2016-08-24 2018-03-01 信越半導体株式会社 Polishing apparatus and wafer polishing method
CN106378698A (en) * 2016-10-27 2017-02-08 上海华力微电子有限公司 Grinding pressure compensation method for chemical mechanical grinding machine
CN107214610A (en) * 2017-05-05 2017-09-29 天津华海清科机电科技有限公司 The online flatness control system of copper CMP
CN107344327A (en) * 2017-05-05 2017-11-14 清华大学 In the method for improved wire flatness of wafer surface
CN107984374A (en) * 2017-11-30 2018-05-04 上海华力微电子有限公司 A kind of detecting real-time device and its method for detecting for chemically-mechanicapolish polishing grinding rate
CN108908063A (en) * 2018-07-20 2018-11-30 清华大学 The control method and control system of polish pressure are adjusted according to consumptive material life cycle
CN109531404A (en) * 2018-11-30 2019-03-29 上海华力微电子有限公司 A kind of grinding system and grinding method for chemical mechanical grinding

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113084692A (en) * 2021-04-27 2021-07-09 上海芯物科技有限公司 Chemical mechanical polishing method and chemical mechanical polishing apparatus
CN113400195A (en) * 2021-07-21 2021-09-17 北京烁科精微电子装备有限公司 Method and system for online partition adjustment of loading and unloading pressure of polishing head
CN114952595A (en) * 2022-06-21 2022-08-30 长鑫存储技术有限公司 Flatness control method, device, equipment and medium
CN114952595B (en) * 2022-06-21 2023-09-22 长鑫存储技术有限公司 Flatness control method, device, equipment and medium
CN117140340A (en) * 2023-10-27 2023-12-01 迈为技术(珠海)有限公司 Wafer grinding control method, device, equipment and medium
CN117140340B (en) * 2023-10-27 2024-01-02 迈为技术(珠海)有限公司 Wafer grinding control method, device, equipment and medium

Similar Documents

Publication Publication Date Title
CN111975469A (en) Chemical mechanical polishing method and polishing system
US11224956B2 (en) Polishing apparatus
US8142260B2 (en) Methods and apparatus for removal of films and flakes from the edge of both sides of a substrate using backing pads
CN100466191C (en) Polishing device
US6840840B2 (en) Apparatus and method for conditioning and monitoring media used for chemical-mechanical planarization
JP4817687B2 (en) Polishing equipment
CN100513076C (en) Polishing apparatus and polishing method
US20080293344A1 (en) Methods and apparatus for polishing a notch of a substrate using a polishing pad
TWI495027B (en) Distance monitoring device
JPH0569310A (en) Device for grinding mirror surface of wafer
TWI241938B (en) Substrate holding apparatus and polishing apparatus
US20080293341A1 (en) Methods and apparatus for using a rolling backing pad for substrate polishing
US7297047B2 (en) Bubble suppressing flow controller with ultrasonic flow meter
JP5291746B2 (en) Polishing equipment
US20030027505A1 (en) Multiport polishing fluid delivery system
CN201960447U (en) Chemical mechanical polishing equipment
JP2001179605A (en) Polishing device and method
JP2005288664A (en) Polishing device and method for detecting completion of polishing pad standing
CN1189924C (en) System for controlling instant-compensuted grinded curved surface
JPH0970753A (en) Polishing method and polishing device
US20200368874A1 (en) Polishing apparatus and polishing method
JP2016078159A (en) Polishing head and polishing apparatus
JP2020040188A (en) Retainer ring, polishing head having the same, and polishing device
JP2023144946A (en) Polishing device and polishing method
Zhang Chemical mechanical polishing and grinding of silicon wafers

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
RJ01 Rejection of invention patent application after publication

Application publication date: 20201124

RJ01 Rejection of invention patent application after publication