KR101272122B1 - Chemical Mechanical Polishing Device - Google Patents

Abstract

The present invention relates to a CMP device, and more specifically, a swing part installed at a predetermined interval apart from a surface on which a CMP pad to be conditioned is placed, one end of which is installed at an upper end of the swing part in a direction perpendicular to the swing part, and based on the swing part. Vibration acceleration installed on the other end of the connection part, the rotating part installed on the other end of the connection part, the rotating part combined with the rotating part, the CMP pad conditioner for connecting the CMP pad and rotating, and the connecting part, and detecting the vibration to measure the vibration acceleration of the CMP pad conditioner. The present invention relates to a CMP apparatus capable of estimating the amount of wear of a CMP pad based on the measured vibration acceleration, including a measuring unit, and predicting a state in which a CMP conditioner is installed or driven.

Description

CPM device {Chemical Mechanical Polishing Device}

The present invention relates to a CMP device, and more specifically, to measure the vibration acceleration of the CMP pad conditioner for conditioning the CMP pad, to predict the amount of wear of the CMP pad conditioner, and to confirm the state of the CMP device, thereby to determine the state of the CMP device. It relates to a CMP device that can be maintained.

CMP technology used in semiconductor devices is used to planarize thin films such as insulating films and metal films formed on semiconductor wafers.

Typical consumable parts used in the CMP process include CMP pads, slurries and CMP pad conditioners. In particular, the CMP pad conditioner has a diamond-like grinder in contact with the CMP pad to scrape or rough the surface of the CMP pad so that the surface state of the new CMP pad is optimized to an initial state with excellent retention of slurry, or The slurry holding capacity of the pad serves to perform conditioning, which is an operation of restoring to maintain the polishing capacity of the CMP pad, and serves to improve the flowability of the slurry supplied to the pad.

While it is possible to measure the removal rate of the wafer during the actual CMP process, it is not possible to measure the wear amount of the CMP pad.

If the amount of wear of the CMP pad is constant, it means that the surface state of the CMP pad is constant, and having a constant CMP pad surface implies that the wafer polishing rate can be kept constant. In addition, when the wear amount of the CMP pad is greatly reduced or greatly increased, the wafer polishing rate is affected as well as the defect of the wafer. Therefore, it is very important to have a constant amount of CMP pad wear in the actual CMP process.

However, although the wear amount of the CMP pad can predict the retention of the wafer polishing rate, there has been no conventional apparatus and method for predicting the wear amount of the CMP pad other than the method of measuring the wafer polishing rate. In addition, the conventional CMP apparatus has no method of checking the driving state of the CMP conditioner or the state in which the CMP conditioner is installed.

Therefore, there is a need for a CMP apparatus capable of predicting the amount of wear of the CMP pad or predicting the installed or driven state of the CMP pad without measuring the wafer polishing rate.

The present inventors have made efforts to solve the above disadvantages and problems of the prior art as a result of measuring the vibration acceleration of the CMP pad conditioner to condition the CMP pad without measuring the polishing rate of the wafer to estimate the wear amount of the CMP pad The present invention has been completed by the development.

Accordingly, an object of the present invention is a swing part installed at a predetermined interval spaced from the surface plate on which the CMP pad to be conditioned is installed, one end of which is installed at the upper end of the swing part in a direction perpendicular to the swing part to rotate on the CMP pad based on the swing part. It includes a rotating part installed at the other end of the connection part to rotate, a CMP pad conditioner that is coupled to the rotating part to condition the CMP pad and rotates, and a vibration accelerometer which detects vibration to measure vibration acceleration of the CMP pad conditioner. It is to provide a CMP device that can predict the amount of wear of the CMP pad by the vibration acceleration, and can predict the state where the CMP conditioner is installed or driven.

The objects of the present invention are not limited to the above-mentioned objects, and other objects not mentioned can be clearly understood by those skilled in the art from the following description.

In order to achieve the above object, the present invention provides a CMP device, characterized in that for measuring the vibration acceleration of the CMP pad conditioner for conditioning the CMP pad.

In addition, the present invention is a swing portion which is installed spaced apart from the surface on which the CMP pad to be conditioned, a predetermined interval, one end is installed on the upper end of the swing axis in a direction perpendicular to the swing portion is rotated on the CMP pad relative to the swing portion A connecting part, a rotating part installed at the other end of the connecting part to rotate, a CMP pad conditioner coupled to the rotating part to rotate and conditioning the CMP pad, and a connecting part installed at the connecting part to sense vibrations and measure vibration acceleration of the CMP pad conditioner. Provided is a CMP apparatus including an acceleration measurement unit.

In a preferred embodiment, the vibration acceleration measuring unit may be installed at any one of the position corresponding to the swing portion of the connecting portion, the position corresponding to the rotating portion, the intermediate point of the connecting portion.

In a preferred embodiment, the vibration acceleration measuring unit may be installed at a position corresponding to the rotating unit of the connecting portion.

In a preferred embodiment, the vibration acceleration of the CMP pad conditioner is proportional to the amount of wear of the CMP pad.

In a preferred embodiment, the vibration acceleration of the CMP pad conditioner is adjusted to have a value of 0.06 to 5.4 m / s ² .

In a preferred embodiment, if the controlled vibration acceleration value of the CMP pad conditioner is out of 0.06 to 5.4 m / s ² , the CMP device is inspected or the CMP pad conditioner is replaced.

In a preferred embodiment, the control unit for generating a check signal of the CMP device or a replacement signal of the CMP pad conditioner when the vibration acceleration measured from the vibration acceleration measurement unit is out of the range of the pre-stored vibration acceleration.

In a preferred embodiment, the pre-stored vibration acceleration range is 0.06 to 5.4 m / s ² .

The present invention has the following excellent effects.

First, according to the CMP apparatus of the present invention, it is possible to predict the wear amount of the CMP pad by measuring the vibration acceleration of the CMP pad conditioner for conditioning the CMP pad.

In addition, the CMP device of the present invention is installed on the upper end of the swing portion in a direction perpendicular to the swing portion, the swing portion is installed at a predetermined interval spaced from the surface on which the CMP pad to be conditioned to rotate on the CMP pad relative to the swing portion It includes a connecting part, a rotating part installed at the other end of the connecting part, a rotating part coupled to the rotating part, and a CMP pad conditioner for adjusting the CMP pad while rotating and a connecting part, and a vibration accelerometer for detecting the vibration acceleration of the CMP pad conditioner by detecting the vibration. The amount of vibration of the CMP pad may be predicted by the measured vibration acceleration, and the CMP conditioner may be installed or driven.

1 is a view showing a schematic view of a CMP apparatus of the present invention;
2 shows a conditioning area of a CMP pad conditioner of the present invention;
3 is a graph showing the amount of pad wear and vibration acceleration according to the method of applying a load to the CMP pad conditioner,
4 and 5 are graphs showing the amount of pad wear and vibration acceleration according to the load of the CMP pad conditioner,
6 is a graph showing the profile of the pad wear amount according to the vibration acceleration value.

Although the terms used in the present invention have been selected as general terms that are widely used at present, there are some terms selected arbitrarily by the applicant in a specific case. In this case, the meaning described or used in the detailed description part of the invention The meaning must be grasped.

Hereinafter, with reference to the preferred embodiment shown in the accompanying drawings will be described in detail the technical configuration of the present invention.

However, the present invention is not limited to the embodiments described herein but may be embodied in other forms. Like reference numerals used to describe the present invention throughout the specification denote like elements.

The present invention relates to a CMP apparatus for measuring vibration acceleration of a CMP pad conditioner for conditioning a CMP pad, predicting a wear amount of the CMP pad at the measured vibration acceleration, and predicting an installed state or a driven state of the CMP pad conditioner.

As a result, by measuring the vibration acceleration of the CMP pad conditioner without separately measuring the polishing rate of the wafer, it is possible to predict the wear of the CMP pad and the life of the CMP pad conditioner while polishing the wafer during the CMP process. In addition, the vibration acceleration of the CMP pad conditioner may be measured to determine whether the CMP pad conditioner is normally installed and normally driven, thereby maintaining a constant state of the CMP device.

1 is a view showing a schematic view of the CMP device of the present invention, Figure 2 is a view showing the conditioning area of the CMP pad conditioner of the present invention, the CMP device 100 of the present invention is a swing unit 130, the connecting portion 140, the rotating unit 150, the CMP pad conditioner 160, and the vibration acceleration measuring unit 170 are configured.

The swing unit 130 is installed spaced apart from the surface 110 on which the CMP pad 120 to be conditioned is placed. For example, the surface plate 110 is placed on the support 111 and horizontally installed on the floor, the swing 130 is installed perpendicular to the floor. Although not shown, the swing unit 130 is configured to include a separate motor, and rotates about a swing shaft by the motor.

One end of the connection part 140 is installed on the upper end of the swing part 130, and the other end of the connection part 140 is installed. The connection part 140 is installed in a direction perpendicular to the swing part 130 and rotates at a predetermined angle on the CMP pad 120 based on the swing part 130.

The rotating part 150 is installed at the other end of the connecting part 140 and rotates. Although not shown, the rotating unit 150 is configured to include a separate motor, and rotates about a rotating shaft by the motor.

The CMP pad conditioner 160 is coupled to the rotating unit 150 to condition the CMP pad 120 while rotating by the rotating unit 150. Conditioning is to initiate the surface state of the CMP pad by scraping or roughing the surface of the CMP pad 120 while the CMP pad conditioner 160 is rotated while the CMP pad conditioner 160 and the CMP pad 120 are in close contact with each other. It refers to a process of optimizing the state or restoring to maintain the polishing ability of the CMP pad.

The conditioning area shown in Fig. 2 represents the area where the CMP pad conditioner 160 is rotated and conditioned by the connecting portion 14100. The CMP pad conditioner 160 rotates while rotating, and at the same time, the surface plate 110 also rotates, so the CMP pad conditioner 160 rotates. Conditioning may occur over the entire surface of the pad 120.

Vibration acceleration measuring unit 170 is installed in the connecting portion 140 to detect the vibration to measure the vibration acceleration of the CMP pad conditioner 160.

In detail, referring to FIG. 1, the vibration acceleration measuring unit 170 may include a position A corresponding to the swing unit 130, a position C corresponding to the rotation unit 150, and a connection unit 140 of the connection unit 140. It can be installed at any position B of the intermediate point.

The vibration acceleration measurement unit 170 may measure vibration acceleration of the CMP pad conditioner 160 although there is a difference in sensitivity depending on vibration even when installed at any position of A to C.

The following are some experimental examples for checking the relationship between the vibration acceleration of the CMP pad conditioner 160 and the pad wear amount during the CMP process.

Experimental Example 1

The CMP process applies a load to the CMP pad conditioner 160 to condition the CMP pad 120 in close contact with the CMP pad conditioner 160. The method of applying the load to the CMP pad conditioner 160 is different for each company that manufactures the CMP apparatus. Here, the method using air, the method using an axis, and the method using a weight will be described.

First, a method using air is a method in which the same amount of air is filled in the entire CMP pad conditioner 160 and the CMP pad 120 is pressed. One axis of rotation transmits force to the center of the CMP pad conditioner 160. In addition, the weight method is a method of transmitting a force by placing a certain weight on the rotating shaft of the CMP pad conditioner 160, rather than using air.

Table 1 shows the vibration acceleration of the CMP pad conditioner 160 according to each load transfer method and the amount of pad wear accordingly.

Load transfer method Pad wear (PWR, μm / hr) Vibration Acceleration (m / s ² ) air method 17.0 0.4 Axis method 20.0 0.5 Weight method 28.0 1.0

In the case of applying a 6 lb load (lbf) to the CMP pad conditioner 160 during the CMP process while maintaining all the same process conditions, according to the method of transmitting the load even when the same load is transmitted in the static state as shown in Table 1 It can be seen that there is a difference between the pad wear amount and the vibration acceleration value. Referring to Table 1 and Figure 3 it can be seen that the amount of pad wear amount and the vibration acceleration proportional.

That is, since the amount of pad wear and vibration acceleration are different depending on the method of transmitting load in each equipment, in order to control the amount of pad wear of the different CMP apparatus 100 to the same level, the load of the CMP pad conditioner is different. I can see.

Experimental Example 2

Based on the result of Experimental Example 1, the load value applied to the CMP pad conditioner 160 to have the same vibration acceleration value as that of Experimental Example 1 using a device that transfers the load using air, such as A device, and its The amount of pad wear at the time of measurement was measured and shown in Table 2.

Vibration Acceleration (m / s ² ) Disc load (lbf) Pad wear (PWR, μm / hr) Pad Wear Amount of Experimental Example 1 0.4 6.0 17.0 17.0 0.5 6.7 19.8 20.0 1.0 8.8 28.4 28.0

For example, when the disc CMP pad conditioner 160 was loaded to have vibration accelerations of 0.4, 0.5, and 1.0 m / s ² as shown in Table 1, the pad wear amount in each case was 17.0, 19.8, and 28.4 µm / hr. This value was almost the same as the pad wear of Experimental Example 1.

In other words, by adjusting the disk load to make the vibration acceleration value the same, the amount of pad wear between different CMP devices can be matched to the same level. Through this, it can be confirmed that the amount of pad wear can be predicted by measuring the vibration acceleration value.

Experimental Example 3

When the load was applied to the CMP pad conditioner 160 by 6 lbf using a device A, and a tolerance was given to a rotating shaft (not shown) that transmits the load to the CMP pad conditioner 160 to artificially generate vibration. Table 3 shows the results of measuring the amount of pad wear when the same vibration acceleration value is the same.

Disc load (lbf) Vibration Acceleration (m / s ² ) Pad wear (PWR, μm / hr) Pad Wear Amount of Experimental Example 1 6.0 0.4 17.0 17.0 6.0 0.5 19.7 20.0 6.0 1.0 28.2 28.0

As shown in Table 3, even if the same load is applied to the CMP pad conditioner 160, it can be seen that the pad wear amount changes as the vibration acceleration value is changed. Therefore, it can be seen that the vibration acceleration value of the CMP pad conditioner 160 can predict the pad wear amount. In addition, the vibration acceleration measurement unit 170 is installed on the rotation unit 150 to measure the vibration acceleration of the CMP pad conditioner 160 so that the state of the CMP apparatus 100 can be checked and the uniform pad wear can be shown. There is an effect that can be set.

Experimental Example 4

Using the A device, the vibration acceleration value when the load of the CMP pad conditioner 160 was changed and the pad wear amount at that time were measured and described in Table 4.

Disc load (lbf) Vibration acceleration (m / s2) Pad wear (PWR, μm / hr) 4.0 0.25 12.4 6.0 0.4 17.0 8.0 0.62 20.6 10.0 0.81 24.3 12.0 1.0 28.5

As shown in Table 4, it can be seen that the vibration acceleration value is proportional to the load of the CMP pad conditioner 160, and it can be confirmed that the pad wear amount of the CMP pad 120 can be estimated by measuring the vibration acceleration. This can also be confirmed with FIG. 4, which shows the measured values of Table 4 graphically.

Experimental Example 5

Using the A device, the vibration acceleration value when the load of the CMP pad conditioner 160 was changed, the pad wear amount, the polishing rate of the oxide wafer, and the defect of the wafer were measured and described in Table 5 below.

Disc load (lbf) Vibration Acceleration (m / s ² ) Pad wear (PWR, μm / hr) Wafer Polishing Rate (Å / min) Wafer Defect Count (ea) Pad profile 2.0 0.06 2.7 2200 120 normal 3.0 0.15 8 2700 5 normal 4.0 0.25 12.4 2755 5 normal 6.0 0.4 17.0 2762 4 normal 8.0 0.62 20.6 2795 2 normal 10.0 0.81 24.3 2788 2 normal 12.0 1.0 28.5 2782 6 normal 20.0 4.0 55.0 2766 5 normal 25.0 5.4 93.0 2588 21 Single wear

Table 5 measured the disk load values listed in Table 4, including 4.0, 6.0, 8.0, 10.0, 12.0 lbf, as well as values from less than 4.0 lbf to greater than 12.0 lbf. When the disk load values were 4.0, 6.0, 8.0, 10.0, and 12.0 lbf, the vibration acceleration values were measured in the same manner as in Table 4, and the pad wear amount was also the same as in Table 4. Vibration acceleration and pad wear according to the disk load shown in Table 4 are also shown in FIG.

When the vibration acceleration value was 0.06m / s ² , conditioning was not performed smoothly, resulting in low wafer polishing rate and increased wafer defects.

On the other hand, when the vibration acceleration value is 5.4m / s ² , the pad wear amount is very large, the pad profile is also not uniform, it was confirmed that there is a problem of shortening the life of the CMP pad 120 due to the uneven wear phenomenon of the CMP pad 120.

Accordingly, it can be seen that the vibration acceleration value measured by sensing the vibration of the CMP pad conditioner 160 has a value of 0.06 to 5.4. Referring to FIG. 6, the profile of the pad wear amount may be confirmed according to the vibration acceleration value. The profile when the vibration acceleration value of 0.06m / s ² and 4.0m / s ² is uniformly shown, while 5.4m / s ^2. When you have the vibration acceleration value of, you can see that the profile is uneven.

Experimental Example 6

In order to check the change in sensitivity of the vibration acceleration measurement unit 170 according to the position where the vibration acceleration measurement unit 170 is installed, a position corresponding to the swing unit 130 of the connection unit 140, corresponding to the rotation unit 150 The vibration acceleration measurement unit 170 is installed at the center of the position and the connection part 140, respectively, and the vibration acceleration is measured by applying a load of 4, 6, and 8 lbf to the CMP pad conditioner 160, and the sensitivity (deviation) is investigated. It is shown in Table 6.

Vibration Acceleration Measurement Location
Vibration Acceleration (m / s ² ) 8lbf 6lbf 4lbf Sensitivity (deviation) a (corresponds to the swing part) 0.25 0.22 0.19 0.06 b (connection midpoint) 0.40 0.36 0.32 0.08 c (correspond to rotating part) 0.62 0.55 0.42 0.20

Referring to FIG. 1, when the vibration acceleration measurement unit 170 is installed at a position corresponding to the swing unit 130 of the connection unit 140 as shown in Table 6, the CMP pad conditioner 160 may have 4 and 6 positions. For example, the vibration acceleration measured at 8 lbf load has a sensitivity of 0.06 when the difference between the highest and lowest values is defined as the sensitivity.

Similarly, when the vibration acceleration measurement unit 170 is installed at the intermediate point (b) of the connection unit 140, the measured vibration acceleration has a sensitivity of 0.08 and is installed at a position corresponding to the rotation unit 150 of the connection unit 140. In this case, the measured vibration acceleration has a sensitivity of 0.20.

That is, the vibration acceleration measurement unit 170 has the greatest sensitivity when installed at the position (c) corresponding to the rotation unit 150 of the connection unit 140, so that it is accurately determined whether there is an abnormal state of the device state and the CMP pad conditioner 160 In order to detect the vibration of the sensor) sensitively, it is preferable to install at a position corresponding to the rotating part 150 of the connection part 140.

As a result, the vibration acceleration of the CMP pad conditioner 160 is a load value of the CMP pad conditioner 160, a method of applying a load to the CMP pad conditioner 160, the tolerance of the rotating part 150 when the CMP pad conditioner 160 is installed By adjusting the position at which the vibration acceleration measuring unit 170 is installed, the vibration acceleration value, such as the wafer polishing rate, the number of wafer defects, the pad wear rate, the pad profile, etc., is well represented, for example, the vibration acceleration value of 0.06 to 5.4 m / s ² . You can have it.

This may be performed manually by an operator, or may be automated with a controller (not shown). The control unit will be described later.

In addition, even when used in the above method, if the vibration acceleration value is not adjusted to have a range of 0.06 to 5.4m / s ^2, the operator can replace the CMP pad conditioner 160.

In addition, different manufacturers of CMP devices apply different loads to the CMP pad conditioner, so if a certain load is applied to the CMP pad conditioner, the same load can be transferred to the CMP pad conditioner for each device while the CMP pad conditioner is stopped. When the CMP pad conditioner swings by the rotation of the connection part, the load values transmitted to the CMP pad conditioner are different.

In addition, even if a load is applied to the CMP pad conditioner in the same manner, due to the tolerances generated when the CMP pad conditioner is installed, the vibration detected by the actual vibration accelerometer is different.

The present invention adjusts the vibration acceleration values of different devices by adjusting the load value of the vibration acceleration CMP pad conditioner, the method of applying a load to the CMP pad conditioner, the tolerance of the rotating part when the CMP pad conditioner is installed, and the position of the vibration acceleration measurement part. This allows to maintain a constant amount of pad wear of different devices, and finally to reduce the variation of wafer polishing rate between devices.

On the other hand, the present invention may further comprise a control unit (not shown).

The CMP apparatus 100 according to the present invention stores the vibration acceleration range in advance, and then compares the vibration acceleration measured from the vibration acceleration measurement unit 170 with the previously stored vibration acceleration, and the vibration acceleration measured is stored in the range of the vibration acceleration. If out of the check signal to check the CMP apparatus 100 or a replacement signal to replace the CMP pad conditioner 160 is generated.

When the control unit generates a check signal, a load value applied to the CMP pad conditioner 160, a method of applying a load, a tolerance of the rotating unit 150 when the CMP pad conditioner 160 is installed, and a position at which the vibration acceleration measuring unit 170 is installed The CMP apparatus 100 may be checked so that the measured vibration acceleration value is adjusted to fall within a range of pre-stored vibration acceleration.

At this time, the range of the vibration acceleration to be stored in advance is preferably 0.06 to 5.4m / s ² as confirmed in the experimental example.

CMP pad conditioner 160 when the measured vibration acceleration value is out of the previously stored vibration acceleration range even when the state of the CMP apparatus 100 is checked using various methods such that the vibration acceleration value falls within the previously stored vibration acceleration range as described above. ), The control unit may generate a replacement signal to allow the operator to replace the CMP pad conditioner 160.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, Various changes and modifications will be possible.

Claims (9)

In a CMP apparatus,
It includes a control unit for measuring the vibration acceleration of the CMP pad conditioner for conditioning the CMP pad, and generating a check signal of the CMP device or a replacement signal of the CMP pad conditioner when the measured vibration acceleration is out of the range of the stored vibration acceleration. ,
When the check signal is generated, the controller adjusts a load value applied to the CMP pad conditioner, a method of applying a load, and a process condition that affects vibration acceleration including the tolerance of the rotating part when the CMP pad conditioner is installed. Check the CMP device to fall within the range of the stored vibration acceleration,
CMP device, characterized in that for generating a replacement signal when the vibration acceleration measured after performing the check is out of the range of the previously stored vibration acceleration.
A swing unit installed spaced apart from the surface on which the CMP pad to be conditioned is placed;
A connecting part having one end installed at an upper end of the swing shaft in a direction perpendicular to the swing part to rotate on the CMP pad based on the swing part;
A rotating part installed at the other end of the connection part to rotate;
A CMP pad conditioner coupled to the rotating part to condition the CMP pad while rotating;
A vibration acceleration measurement unit installed in the connection unit and detecting vibration and measuring vibration acceleration of the CMP pad conditioner; And
And a controller configured to generate a check signal of the CMP device or a replace signal of the CMP pad conditioner when the vibration acceleration measured by the vibration acceleration measurement unit is out of a range of previously stored vibration acceleration.
When the check signal is generated, the controller adjusts a load value applied to the CMP pad conditioner, a method of applying a load, and a process condition that affects vibration acceleration including the tolerance of the rotating part when the CMP pad conditioner is installed. Check the CMP device to fall within the range of the pre-stored vibration acceleration,
CMP device, characterized in that for generating a replacement signal when the vibration acceleration measured after performing the check is out of the range of the previously stored vibration acceleration.
The method of claim 2,
The vibration acceleration measuring unit is installed in any one of the position corresponding to the swing portion of the connection portion, the position corresponding to the rotating portion, the intermediate point of the connection portion.
The method of claim 3,
The vibration acceleration measuring unit is installed in the position corresponding to the rotating part of the connecting portion CMP apparatus.
The method according to claim 1 or 2,
CMP device, characterized in that the vibration acceleration of the CMP pad conditioner is proportional to the amount of wear of the CMP pad.
The method according to claim 1 or 2,
CMP device characterized in that the vibration acceleration of the CMP pad conditioner is adjusted to have a value of 0.06 to 5.4m / s ² .
The method according to claim 6,
CMP device check or replace the CMP pad conditioner when the adjusted vibration acceleration value of the CMP pad conditioner is out of 0.06 to 5.4m / s ² .
delete The method according to claim 1 or 2,
The pre-stored vibration acceleration range is 0.06 to 5.4m / s ² CMP device.

Images