KR20090118751A - Method and apparatus of chemical mechanical polishing - Google Patents

Abstract

PURPOSE: A chemical mechanical polishing apparatus and a method thereof are provided to largely reduce thickness change of an insulation film regardless of lifetime of a polishing pad, a polishing head, or a disc used in a polishing apparatus by re-polishing the insulation film for a second polishing time. CONSTITUTION: A chemical mechanical polishing method comprises the following steps: a step for polishing an insulation film formed on a wafer for a first polishing time(20); a step for measuring thickness of the polished insulation film(26); a step for calculating a second polishing time about the insulation film based on the measured thickness(23); and a step for re-polishing the insulation film for the second polishing time(24).

Description

Method and apparatus of chemical mechanical polishing

The present invention relates to a chemical mechanical polishing method, and more particularly, to a chemical mechanical polishing method and apparatus for an insulating film, a metal film and a back surface of a wafer formed on a wafer.

As semiconductor devices become more integrated and higher in capacities, a step of a material film formed on a semiconductor substrate, for example, a metal wiring, is increasing. This step of the metal wiring may make it difficult to pattern the metal wiring later. In particular, in the memory device, the step difference between the cell region and the peripheral region increases, and the higher the metal wiring, the more serious the step problem. Therefore, in the manufacture of semiconductor devices, planarization techniques for planarizing the material film or the semiconductor substrate itself are essential. Representative of the planarization technique is a chemical mechanical polishing (CMP) technique for flattening a material film in parallel with chemical polishing and mechanical polishing.

The CMP device supplies a flexible polishing pad, a polishing head that rotates while applying pressure to the wafer, a pad conditioner to maintain a good pad condition, and a slurry, which is a polishing solution. It includes a device. The CMP process supplies fine abrasive particles and added slurry to the chemical solution between the wafer and the pad, pressurizes and rotates the polishing head, and performs surface polishing of the wafer. Under the CMP process conditions, the platen to which the wafer and the polishing pad are bonded is rotated in a fixed direction which is structurally preset in the installation. The platen rotates in the same direction and at the same speed to obtain a uniform amount of wear on the wafer front.

According to the conventional CMP method, when the target thickness of the wafer is 3500 mm 3, the thicknesses of the several wafers included in one lot (convenient to align and transport a plurality of wafers) are 3200 to 3800. In other words, a thickness difference of approximately 600 mm may occur between wafers. In addition, the thickness of one wafer is 2900 to 4100 mm 3, so that a thickness difference of about 1200 mm between a center and an edge may occur in one wafer. In addition, the thickness of one chip included in the wafer is 2850 to 4150 mW, and a thickness difference of about 1500 mW may occur in one chip according to the difference in density.

Accordingly, when polishing a wafer and etching a contact for a certain polishing time, due to the above-described thickness difference, the contact may not be etched properly (pun- cessed) or etched too much, Problems such as leakage between contacts and polysilicon can occur.

The problem to be solved by the present invention is to provide a chemical mechanical polishing method that can minimize the thickness variation of the oxide film formed on the wafer.

In addition, another object of the present invention is to provide a chemical mechanical polishing method capable of minimizing the thickness variation of the metal film formed on the wafer.

In addition, another object of the present invention is to provide a chemical mechanical polishing apparatus capable of minimizing the thickness variation of the wafer surface.

In addition, another object of the present invention is to provide a chemical mechanical polishing method that can minimize the thickness variation of the back surface of the wafer.

According to another aspect of the present invention, there is provided a chemical mechanical polishing method comprising polishing an insulating film formed on a wafer during a first polishing time; Measuring a thickness of the polished insulating film; Calculating a second polishing time for the insulating film based on the measured thickness; And regrinding the insulating layer during the second polishing time.

The polishing of the insulating film during the first polishing time may include polishing the insulating film on the first platen for a first fixed time; And polishing the insulating film polished on the first platen for a second fixed time on the second platen, wherein the sum of the first fixed time and the second fixed time corresponds to the first polishing time. do.

The regrinding of the insulating film during the second polishing time may include regrinding the insulating film during the second polishing time on a third platen, and the second polishing time may be a variable time depending on the thickness of the polished insulating film.

The cleaning of the wafer, wherein the insulating film is polished during the first polishing time, further includes cleaning the wafer, and measuring the thickness of the polished insulating film measures the thickness of the insulating film on the cleaned wafer.

The method includes measuring a thickness of the regrind insulating film; Determining whether to re-grind the insulating film based on the thickness of the re-polished insulating film; And regrinding or outputting the regrind insulating film according to the determination result. The method further includes cleaning the wafer on which the insulating film has been repolished during the second polishing time. Measuring the thickness of the re-polished insulating film measures the thickness of the cleaned and polished insulating film.

Regrinding or outputting the regrind insulating film again regrinds the regrind insulating film on the third platen during the second polishing time when it is determined to perform regrinding of the insulating film.

The insulating layer is an inter layer dielectric (ILD) or shallow trench isolation (STI). Polishing the insulating film during the first polishing time is 50 to 90% of the total polishing amount.

In addition, the chemical mechanical polishing method according to the present invention for solving the above another problem comprises the steps of polishing a metal film formed on the wafer during the first polishing time; Measuring a thickness of the polished metal film; Calculating a second polishing time for the metal film based on the measured thickness; And regrinding the metal film during the second polishing time.

The method further includes cleaning the wafer with the metal film polished during the first polishing time, and measuring the thickness of the polished metal film measures the thickness of the metal film on the cleaned wafer. The method includes measuring a thickness of the regrind metal film; Determining whether to regrind the metal film based on the thickness of the repolished metal film; And regrinding or outputting the regrind metal film according to the determination result. The method further includes cleaning the wafer with the metal film re-polished during the second polishing time, and measuring the thickness of the re-polished metal film measures the thickness of the cleaned re-polished metal film. The metal film is at least one of tungsten (W), aluminum (Al), and copper (Cu).

In addition, the chemical mechanical polishing apparatus according to the present invention for solving the above another problem is a first platen for polishing the wafer surface during the first polishing time; A second platen for polishing the wafer surface polished from the first platen for a second polishing time; A thickness measuring unit measuring a thickness of the wafer surface polished from the second platen and calculating a third polishing time for the wafer surface based on the measured thickness; And a third platen for regrinding the wafer surface for the third polishing time.

The apparatus further includes a cleaning section for cleaning the wafer polished from the second platen and supplying the cleaned wafer to the thickness measurement section. The thickness measuring unit measures the thickness of the wafer surface re-polished in the third platen, determines whether to re-grind the surface of the wafer based on the measured thickness, and the re-polished wafer according to the determination result. Regrind or print the surface again. The apparatus further includes a cleaning section for cleaning the wafer polished from the third platen.

In addition, the chemical mechanical polishing method according to the present invention for solving the another problem comprises the steps of polishing the back of the wafer for a first time; Measuring a thickness of the back side of the polished wafer; Calculating a second polishing time for the backside of the wafer based on the measured thickness; And regrinding the back surface of the wafer during the second polishing time.

The method further includes cleaning the wafer during the first polishing time, and measuring the thickness of the backside of the polished wafer measures the thickness of the backside on the cleaned wafer. The method includes measuring a thickness of a back side of the regrind wafer; Determining whether to regrind the backside of the wafer based on the thickness of the backside of the regrind wafer; And regrinding or outputting a rear surface of the regrind wafer according to the determination result. The method further includes cleaning the regrind wafer during the second polishing time, and measuring the thickness of the backside of the regrinded wafer measures the thickness of the backside of the cleaned regrind wafer. do.

According to the present invention, an insulating film formed on a wafer is polished during a first polishing time, and the thickness of the polished insulating film is measured to calculate a second polishing time for the insulating film based on the measured thickness, and during the second polishing time. By re-polishing the insulating film, it is possible to greatly reduce the thickness variation of the insulating film between different lots, wafers, or chips inside the wafer, regardless of the life of the polishing pad, the polishing head, or the disk used in the polishing apparatus.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The embodiments of the present invention are provided to more fully explain the present invention to those skilled in the art, and the following examples can be modified in various other forms, and the scope of the present invention is It is not limited to an Example. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In addition, the thickness or size of each layer in the drawings is exaggerated for convenience and clarity of description.

Throughout the specification, when referring to one component, such as a film, region, or substrate, being located on, “connected”, or “coupled” to another component, the one component is directly It may be interpreted that there may be other components "on", "connected", or "coupled" in contact with, or interposed therebetween. On the other hand, when one component is said to be located on another component "directly on", "directly connected", or "directly coupled", it is interpreted that there are no other components intervening therebetween. do. Like numbers refer to like elements. As used herein, the term "and / or" includes any and all combinations of one or more of the listed items.

Although the terms first, second, etc. are used herein to describe various members, parts, regions, layers, and / or parts, these members, parts, regions, layers, and / or parts are defined by these terms. It is obvious that not. These terms are only used to distinguish one member, part, region, layer or portion from another region, layer or portion. Thus, the first member, part, region, layer or portion, which will be discussed below, may refer to the second member, component, region, layer or portion without departing from the teachings of the present invention.

Also, relative terms such as "top" or "above" and "bottom" or "bottom" may be used herein to describe the relationship of certain elements to other elements as illustrated in the figures. It may be understood that relative terms are intended to include other directions of the device in addition to the direction depicted in the figures. For example, if the device is turned over in the figures, elements depicted as present on the face of the top of the other elements are oriented on the face of the bottom of the other elements. Thus, the exemplary term "top" may include both "bottom" and "top" directions depending on the particular direction of the figure. If the device faces in the other direction (rotated 90 degrees relative to the other direction), the relative descriptions used herein can be interpreted accordingly.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms "a", "an" and "the" may include the plural forms as well, unless the context clearly indicates otherwise. Also, as used herein, "comprise" and / or "comprising" specifies the presence of the mentioned shapes, numbers, steps, actions, members, elements and / or groups of these. It is not intended to exclude the presence or the addition of one or more other shapes, numbers, acts, members, elements and / or groups.

1 is a block diagram showing a chemical mechanical polishing apparatus according to an embodiment of the present invention.

Referring to FIG. 1, a chemical mechanical polishing apparatus includes a polishing unit 11 and a cleaning unit 12.

The polishing unit 11 includes a first platen 111, a second platen 112, a thickness measuring unit 113, and a third platen 114 to chemically and mechanically polish the wafer. In another embodiment of the present invention, the number of platens can be changed. More specifically, the polishing unit 11 chemically and mechanically polishes a back surface of a wafer or a material film such as an insulating film or a metal film formed on the wafer. Hereinafter, for convenience of description, the surface of the wafer is described regardless of the type of material film formed on the wafer or the back surface of the wafer.

A first polishing pad is attached onto the first platen 111, and a wafer is seated on the surface of the first polishing pad during polishing. The polishing unit 11 supplies the slurry while the wafer is in contact with the surface of the first polishing pad to chemically react the surface of the wafer, and moves the first platen 111 and the polishing head relative to each other to mechanically repair the wafer surface. By polishing, the thickness of the wafer surface is removed by a first removal amount during the first polishing time. Here, the polishing head attaches and transfers the wafer, and during polishing, the wafer is brought into contact with the polishing pad surface to apply pressure. Here, the first polishing time is a fixed time.

Similarly, a second polishing pad is attached to the second platen 112, and a wafer polished from the first platen 111 is seated on the surface of the second polishing pad during polishing. The polishing unit 11 supplies the slurry while the wafer is in contact with the surface of the second polishing pad to chemically react the wafer surface, and moves the second platen 112 and the polishing head relative to each other to mechanically repair the wafer surface. Polishing removes the thickness of the wafer surface by the second removal amount during the second polishing time. Here, the second polishing time is a fixed time.

In one embodiment of the present invention, the amount of polishing in the first and second platens 111 and 112, that is, the sum of the first removal amount and the second removal amount is about 50 to 90% of the total removal amount.

The cleaning unit 12 cleans the wafer polished on the second platen 112, and supplies the cleaned wafer to the thickness measuring unit 113 included in the polishing unit 11. In addition, the cleaning unit 12 cleans the wafer polished on the third platen 114, and supplies the cleaned wafer to the thickness measuring unit 113 again.

The thickness measuring unit 113 calculates a third polishing time for the wafer in the third platen 114 by measuring the thickness of the surface of the cleaned wafer. More specifically, the thickness measuring unit 113 increases the third polishing time when the thickness of the surface of the wafer is thicker than the target value, and decreases the third polishing time when the thickness of the wafer surface is thinner than the target value. For example, when performing chemical mechanical polishing on an interlayer dielectric (ILD) formed on a wafer, the thickness measuring unit 113 calculates a third polishing time by measuring the thickness of the interlayer dielectric.

As such, one embodiment of the present invention utilizes a time polish method that adjusts the polishing time to achieve polishing to a desired thickness. The time polish method is a method in which the polishing is performed for a predetermined time in consideration of the polishing rate at which the wafer is polished to approach the polishing target. Conventionally, the wafer is polished using statistical values, but in one embodiment of the present invention, the thickness of the polished wafer is directly measured and repolished.

A third polishing pad is attached onto the third platen 113, and the cleaned wafer is seated on the third polishing pad surface during polishing. The polishing unit 11 supplies the slurry while the wafer is in contact with the surface of the third polishing pad to chemically react the surface of the wafer, and moves the third platen 113 and the polishing head relative to each other to mechanically repair the wafer surface. By polishing, the thickness of the wafer surface is removed by a third removal amount during the third polishing time. Here, the sum of the first to third removal amounts corresponds to the target polishing amount of the entire wafer. The wafer polished on the third platen 113 is again supplied to the cleaning unit 12. Here, the third polishing time is a variable time according to the result calculated by the thickness measuring unit 113.

The cleaning unit 12 cleans the polished wafer and then supplies the wafer to the thickness measuring unit 113 again. Subsequently, the thickness measuring unit 113 measures the thickness of the wafer surface to determine whether the measured thickness falls within a standard range. More specifically, the thickness measuring unit 113 determines that the wafer is to be output when the thickness of the wafer surface falls within the standard range, that is, when the thickness of the target wafer surface is close to the target surface. In addition, the thickness measuring unit 113 determines that the wafer is output to the third platen 114 when the thickness of the wafer surface exceeds the standard range, that is, the thickness of the target wafer surface is thicker. In this case, the third platen 114 polishes the wafer surface again. Meanwhile, when the thickness of the wafer surface is less than the standard range, that is, when the thickness of the wafer surface is smaller than the thickness of the target wafer surface, the thickness measuring unit 113 determines that the material film on the wafer surface is to be redeposited.

In another embodiment of the present invention, the cleaning unit 12 may clean the polished wafer and immediately output the instead of supplying it to the thickness measuring unit 113.

2 is a flowchart illustrating a chemical mechanical polishing method according to an embodiment of the present invention.

Hereinafter, a method of performing chemical mechanical polishing on an interlayer insulating film (ILD) formed on a wafer surface according to an embodiment of the present invention will be described in time series with reference to FIGS. 1 and 2. However, as described above, the present invention also applies to chemical mechanical polishing of an insulating film or metal film formed on the wafer surface or the back surface of the wafer.

In step 20, the interlayer insulating film formed on the surface of the wafer is polished on the first platen P1.

In step 21, the interlayer insulating film on the wafer polished from the second platen P2 to the first platen P1 is polished.

In step 22, the wafer polished from the second platen P2 is cleaned.

In step 23, the regrinding time is calculated by measuring the thickness Tox of the interlayer insulating film on the cleaned wafer.

In step 24, the wafer is regrind for the regrinding time in the third platen P3.

In step 25, the wafer regrind in the third platen P3 is cleaned.

In step 26, the thickness of the interlayer insulating film on the cleaned wafer is measured. In this case, if the measured thickness of the interlayer insulating film exceeds the standard range, the process proceeds to 24 steps, and if the measured thickness of the interlayer insulating film falls below the standard range, the process proceeds to step 27, and the thickness of the measured interlayer insulating film is the standard range. If it is mine, by outputting the wafer, the procedure ends.

In step 27, an interlayer insulating film having a predetermined thickness is redeposited on the wafer surface.

FIG. 2 illustrates a chemical mechanical polishing method for an interlayer insulating film formed on a wafer in time series. As described above, an embodiment of the present invention provides a chemical mechanical polishing method for shallow trench isolation (STI) formed on a wafer. Also applies. STI refers to the formation of trenches for electrical isolation of individual devices in semiconductor device manufacturing. Briefly, STI chemical mechanical polishing is performed by first depositing a silicon nitride on a wafer and forming a trench using a photolithography process and a dry etching process. Thereafter, the trench outer wall is oxidized by a high temperature thermal process, and then the inside of the trench is filled with oxide using a rapid deposition method. Subsequently, after the oxide film is removed through the CMP process, the remaining nitride film is removed using a plasma etching method to electrically isolate the devices by forming trenches filled only with an insulating material.

In addition, as described above, an embodiment of the present invention is also applied to a chemical mechanical polishing method, that is, a damascene process, for a metal film formed on a wafer. Here, the damascene process is a process used when making metal wiring in a semiconductor, and uses aluminum, tungsten, or copper.

In the metal wiring process using aluminum, aluminum, which is a wiring material, is first deposited on the surface, and then an aluminum wiring pattern is formed using a photolithography process and a dry etching process. An oxide film layer is applied to insulate around the wiring line thus formed, and the generated request portion is planarized by a chemical mechanical polishing process.

Meanwhile, in the metal wiring process using copper, an insulating oxide layer is first formed on the surface, and then a photosensitive film is patterned through an optical lithography process, and a wiring line is formed inside the insulating layer by dry etching. After that, copper, which is a wiring material, is applied by electroplating, and then, by chemical mechanical polishing, all materials other than copper existing in the wiring line are polished and removed. When the insulating film is again deposited on the wiring thus formed, the copper wiring process is completed.

Figure 3 shows the change in the amount of polishing when the chemical mechanical polishing according to the prior art.

Referring to FIG. 3, the horizontal axis represents the life of the polishing pad, and the vertical axis represents the polishing amount in kPa. Polishing pads used in chemical mechanical polishing apparatus have a lesser polishing amount per second as they have been in use. For example, the polishing amount per second is 35.7 mW / s when the polishing pad is not old, and the polishing amount per second is 25.3 mW / s when the old polishing pad is used. In this case, for example, when the target polishing amount is 2200 kPa, the actual polishing amount is 1900 to 2500 kPa, with a variation of approximately 600 kPa depending on the life of the polishing pad.

3 shows a change in polishing amount according to the life of the polishing pad, but this is only an example, and the change in polishing amount according to the life of the polishing head and the disk obtains similar results.

As described above, according to the conventional method, after measuring the surface thickness of the wafer input to the polishing portion, that is, the wafer that has not been polished at all, the third polishing time for performing polishing on the third platen is calculated. . In this case, since the difference between the input wafer thickness and the target wafer thickness is quite large, the thickness of the wafer to be removed, that is, the amount of polishing is large. As described above, when the polishing amount is large, the amount of change in removal amount increases according to the life of the polishing pad, the life of the disk, or the amount of change between the polishing heads.

Figure 4 shows the change in the amount of polishing when chemical mechanical polishing according to an embodiment of the present invention.

4, the horizontal axis represents the life of the polishing pad or disk, and the vertical axis represents the polishing amount in kPa. For example, in the case where the target polishing amount is 440 kPa, the actual polishing amount is 380-535 kPa, which is about 155 kPa depending on the life of the polishing pad or disk.

As such, according to an embodiment of the present invention, the surface thickness is not measured on the wafer input to the polishing unit, but the polishing is performed for a predetermined time after being input to the polishing unit (eg, the first and second The surface thickness is measured on the wafer, where polishing is performed on the platen. As a result, since the removal amount to be substantially polished in the third platen is reduced, the amount of change in the removal amount is also reduced, so that the difference in the thickness of the surface between the wafers on which the chemical mechanical polishing process is performed or the chips inside the wafer is not large.

5 illustrates a change in thickness of the interlayer insulating film on the wafer surface when the chemical mechanical polishing method according to the exemplary embodiment of the present invention is applied.

Referring to FIG. 5, when the target thickness Tox of the interlayer insulating film on the wafer surface is 3500 mW according to the conventional method, a variation of about 500 mW occurs. However, according to one embodiment of the present invention, when the target thickness of the interlayer insulating film on the wafer surface is 3100 mm 3, a change amount of about 140 mm 3 occurs. As such, by applying the chemical mechanical polishing method according to an embodiment of the present invention, it is possible to greatly reduce the thickness difference of the interlayer insulating film between the lots, the wafers, or the chips inside the wafer.

The invention described above can also be embodied as computer readable code on a computer readable storage medium. Computer-readable storage media includes all types of storage devices on which data readable by a computer system is stored. Examples of computer-readable storage media include ROM, RAM, CD-ROM, DVD, magnetic tape, floppy disks, optical data storage, flash memory, and the like, and also in the form of carrier waves (for example, transmission over the Internet). It also includes implementations. The computer readable storage medium can also be distributed over network coupled computer systems so that the computer readable code is stored and executed in a distributed fashion. Here, the program or code stored in the storage medium means that a computer or the like is expressed as a series of instruction commands used directly or indirectly in an apparatus having an information processing capability to obtain a specific result. Thus, the term computer is used to mean all devices having an information processing capability for performing a specific function by a program including a memory, an input / output device, and an arithmetic device, despite the name actually used.

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and various substitutions, modifications, and changes are possible within the scope not departing from the technical spirit of the present invention. It will be evident to those who have knowledge of.

1 is a block diagram showing a chemical mechanical polishing apparatus according to an embodiment of the present invention.

2 is a flowchart illustrating a chemical mechanical polishing method according to an embodiment of the present invention.

Figure 3 shows the change in the amount of polishing when the chemical mechanical polishing according to the prior art.

Figure 4 shows the change in the amount of polishing when the chemical mechanical polishing according to an embodiment of the present invention.

5 illustrates a change in thickness of the interlayer insulating film on the wafer surface when the chemical mechanical polishing method according to the exemplary embodiment of the present invention is applied.

Claims (20)

Polishing the insulating film formed on the wafer during the first polishing time; Measuring a thickness of the polished insulating film; Calculating a second polishing time for the insulating film based on the measured thickness; And And regrinding the insulating film for the second polishing time. The method of claim 1, Polishing the insulating film during the first polishing time Polishing the insulating film on a first platen for a first fixed time; And Polishing the insulating film polished on the first platen for a second fixed time on the second platen, The sum of the first set time and the second set time correspond to the first polishing time. The method of claim 1, Regrinding the insulating film for the second polishing time may include regrinding the insulating film for the second polishing time on a third platen, Wherein the second polishing time is a variable time depending on the thickness of the polished insulating film. The method of claim 1, And cleaning the wafer, in which the insulating film is polished during the first polishing time. The method of claim 4, wherein Measuring the thickness of the polished insulating film comprises measuring the thickness of the insulating film on the cleaned wafer. The method of claim 1, Measuring a thickness of the repolished insulating film; Determining whether to re-grind the insulating film based on the thickness of the re-polished insulating film; And And re-grinding or outputting the re-polished insulating film according to the determination result. The method of claim 6, And cleaning the wafer with the insulating film re-polished during the second polishing time. The method of claim 7, wherein And measuring the thickness of the re-polished insulating film comprises measuring the thickness of the cleaned and re-polished insulating film. The method of claim 6, Regrinding or outputting the regrind insulating film may include regrinding the regrind insulating film on the third platen during the second polishing time when it is determined to regrind the insulating film again. Chemical mechanical polishing method. The method of claim 1, The insulating film is an interlayer dielectric (ILD) or shallow trench isolation (STI) characterized in that the chemical mechanical polishing method. The method of claim 1, The polishing of the insulating layer during the first polishing time comprises grinding 50 to 90% of the total polishing amount. Polishing the metal film formed on the wafer during the first polishing time; Measuring a thickness of the polished metal film; Calculating a second polishing time for the metal film based on the measured thickness; And And regrinding the metal film during the second polishing time. The method of claim 12, Cleaning the wafer, in which the metal film is polished, during the first polishing time, And measuring the thickness of the polished metal film comprises measuring the thickness of the metal film on the cleaned wafer. The method of claim 12, Measuring a thickness of the repolished metal film; Determining whether to regrind the metal film based on the thickness of the repolished metal film; And And re-grinding or outputting the re-polished metal film according to the determination result. The method of claim 14, Cleaning the wafer on which the metal film has been repolished during the second polishing time, Measuring the thickness of the regrind metal film comprises measuring the thickness of the cleaned regrind metal film. The method of claim 12, The metal film is a chemical mechanical polishing method, characterized in that at least one of tungsten (W), aluminum (Al) and copper (Cu). A first platen for polishing the wafer surface for a first polishing time; A second platen for polishing the wafer surface polished from the first platen for a second polishing time; A thickness measuring unit measuring a thickness of the wafer surface polished from the second platen and calculating a third polishing time for the wafer surface based on the measured thickness; And And a third platen for regrinding the wafer surface during the third polishing time. The method of claim 17, And a cleaning unit for cleaning the wafer polished from the second platen and supplying the cleaned wafer to the thickness measurement unit. The method of claim 17, The thickness measuring unit measures the thickness of the wafer surface re-polished in the third platen, determines whether to re-grind the surface of the wafer based on the measured thickness, and the re-polished wafer according to the determination result. A chemical mechanical polishing apparatus characterized by regrinding or outputting a surface again. The method of claim 19, And a cleaning unit for cleaning the wafer polished from the third platen.

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