KR100692313B1 - A chemical mechanical polishing apparatus - Google Patents

Abstract

The present invention relates to a CMP device, and more particularly, it is possible to improve the polishing operation efficiency while minimizing the amount of slurry used, and to prevent the wafer from being removed from the polishing carrier during the polishing operation. The present invention relates to a CMP device that can easily be equipped with a point detection device and minimizes the overall size of the device. In the CMP apparatus according to the present invention for achieving the above object, the wafer is attached to the polishing platen and the carrier lower surface and is moved up and down on the lower surface of the polishing plate at the upper side of the polishing platen, A CMP apparatus comprising a polishing head portion for bringing a lower surface into contact with the polishing pad at a predetermined pressure, wherein the polishing platen is capable of linear reciprocating movement in a direction orthogonal to the rotation axis, thereby providing a linear reciprocating means and a polishing plate. And rotating means for rotating at low speed.

Polishing pad, polishing platen, wafer, straight line, reciprocating, moving, vibration

Description

CMP apparatus {A chemical mechanical polishing apparatus}

1 is a schematic configuration diagram of a CMP device according to the prior art.

FIG. 2 is a plan view showing a state in which a polishing head is disposed on the polishing plate in FIG. 1; FIG.

Figure 3 is a side view showing the configuration of the CMP device according to the present invention.

Figure 4 is a detailed view of the main part of the present invention.

5 is a view showing an installation state of the CMP device of the present invention.

<Description of Symbols for Main Parts of Drawings>

100: CMP device body 200: polishing head device

201: wafer 210: carrier

220: motor 230: carrier rod

240: cylinder 300: polishing plate

310: polishing base base 320: polishing pad

400: servo motor 410: servo motor rotary shaft

510: vibration table 511: fixed portion

520: vibration base 521: vibration base plate

522: oil sealing kit 523a, 523b: support

524: guide rod 530: oil compressor

600: vibration generator 610: vibration rod

700: grinding head feed means 710: feed rod

800: end point detection device

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor CMP device, and more particularly, to improve polishing efficiency, to easily mount an end point detecting device, and to remove a wafer from a polishing carrier during polishing. The present invention relates to a CMP device that can prevent the problem and reduce the overall size of the device as much as possible.

Recently, semiconductor devices have been highly integrated due to the development of semiconductor manufacturing technology. To achieve high integration of semiconductor devices, planarization of oxide layers and wiring of metal (metal-W, Al, Cu, etc.) films are performed. A planarization technique is required, and a CMP (Chemical Mechanical Polishing / Planarization) process is referred to as a method for planarizing the film quality.

The CMP process is a process of planarizing a film formed on a wafer surface, that is, an oxide film or a metal wiring, during a semiconductor device manufacturing process. The wafer surface is chemically reacted by a chemical solution of a slurry containing fine particles. It is a process of physically polishing the surface of the chemically reacted wafer with the fine particles and polishing pad included in.

The conventional CMP apparatus used in the CMP process of polishing the surface of the wafer by using the slurry and the polishing pad as described above, as shown in Figure 1, the polishing plate to rotate in the axial direction about the rotation axis (3a) (3), a polishing pad (4) attached to the upper front surface of the polishing plate (3), and a wafer (1) mounted on the lower surface of the polishing plate (3) with the rotation axis (2a) as the center of the upper side of the polishing plate (3). In addition, the polishing head 2 is moved up and down on the lower surface to bring the lower surface of the wafer 1 into contact with the polishing pad 4 at a predetermined pressure, and the lower surface and the polishing pad 4 of the wafer 1. It consists of the slurry supply part 6a which supplies a slurry between the ()).

Here, the rotational force of the motor 5 supported by the base 8 is transmitted to the reducer 7a through the belt 6, and the surface base 9 is mounted in a direction orthogonal to the rotation shaft 3a connected to the reducer. The base 9 may be equipped with a water cooling device on which the surface plate 3 is mounted.

As shown in FIG. 2, the polishing heads 2 are arranged about four along the edges of the upper surface of the polishing plate 3. In many cases, one head and one head is used. In this case the plate will rotate in place and the head will swing (slowly move) from side to side with a large trajectory.

However, the prior art configured as described above has the following problems.

First, the polishing platen 3 is rotated to carry out polishing, and the slurry is not used for polishing due to the centrifugal force and the adhesion between the wafer and the polishing pad surface, and most of the slurry is discharged. Increasing the number of revolutions of (3) increases the rotational force by that much, there is a disadvantage that the amount of the slurry used increases.

Second, when the rotational force of the polishing plate 3 increases, the difference in the angular velocity between the center portion and the edge portion of the polishing plate 3 increases, resulting in a defect in which the wafer 1 is separated from the polishing head 2. There was a problem that the stability is lowered.

Third, the polishing head 2 is rotated together with the polishing plate 3 in a state where a predetermined pressure is applied in a downward direction, and the rotating shafts 2a and 3a rotate the polishing head 2 and the polishing plate 3. There was a difficulty to design structurally so that the balance of) is achieved.

Fourth, since the polishing work amount of the wafer 1 is determined by the rotation of the polishing plate 3 and the pressure of the polishing head 2, there is a limit in increasing the polishing work amount by the conventional method.

Fifth, in the prior art, the slurry is supplied at a predetermined temperature, and there is a difference in temperature gradient and chemical reaction of the wafer due to the temperature difference between the edge and the center of the wafer, thereby affecting the planarization.

Sixth, in the prior art, as shown in Fig. 2, the wafer 1 having a constant diameter is polished only in the edge region of the polishing plate 3, and the polishing operation cannot be performed in the center region A. In order to cause a waste of work space and even to process a larger number of wafers 1, the size of the polishing plate 3 must be enlarged, which causes a problem in that the size of the equipment cannot be reduced as a whole.

Seventh, in order to find the end point of the CMP operation, the prior art has identified the end point by the amount of light reflected by shooting a laser through a transparent window on the polishing pad. There is a problem that an error occurs due to interference, and this structure complicates the device. In addition, the end point was identified by checking the load on the motor that rotates the surface plate. However, the load did not always change constantly according to the surface state of the wafer. There is about 30% over polishing time to make up for this. This leads to a waste of slurry as well as a decrease in productivity.

The present invention has been made to solve the above problems, it is possible to improve the polishing operation efficiency while reducing the amount of slurry to a minimum, it is possible to prevent the wafer from being separated from the polishing head during the polishing operation, Effidi can be easily mounted, CMP operations can be carried out with a minimum plate size, that is, a minimum polishing pad size slightly larger than the diameter of the wafer (larger than the vibration width), and the overall size of the device can be reduced as much as possible. The purpose of the present invention is to provide a CMP device.

CMP apparatus according to the present invention for achieving the above object, a base plate, a polishing plate mounted on the base plate and the polishing pad is attached to the upper surface, and a wafer mounted on the lower surface of the upper surface of the polishing platen In the CMP apparatus comprising a polishing head which rotates by a rotation axis at the same time and is moved up and down to bring the lower surface of the wafer into contact with the polishing pad at a predetermined pressure.

And a polishing table linear reciprocating means for enabling linear reciprocating movement of the polishing table in a direction orthogonal to the polishing head device, and polishing table rotating means for rotating the polishing table at a predetermined speed.

Here, the linear reciprocating means as a vibration means, means a configuration of a vibrator, a vibration table, a vibration base, the rotation means means a servo motor device.

The reason why the polishing table rotates is to evenly use the polishing pad surface attached to the polishing table without directivity, and is not intended to increase the removal rate. The polishing amount in the present invention mainly depends on the vibration speed and the pressure of the polishing head.

The present invention, the body of the CMP device, the vibration base and the vibrator is fixed to the inner bottom of the body, and the horizontal vibration is installed on top of the vibration base is connected to the vibration rod of the vibrator to move straight reciprocating A servo table fixed to the vibration table, the servo motor for generating rotational force through the rotary shaft, a base plate fixed to the upper part of the rotary shaft of the servo motor, and fixed to the upper part of the base table for rotational movement And a polishing plate for horizontal vibration movement, a polishing pad attached to an upper surface of the polishing plate, and installed downward from an upper portion of the body to be moved up and down with rotational movement so that the wafer contacts the polishing pad at a predetermined pressure. And a polishing head device for mounting a wafer on the lower surface.

In addition, the present invention further comprises a polishing head moving means for horizontally moving the polishing head device, wherein the polishing head moving means moves horizontally to the outside of the polishing platen, and the wafer is mounted on a carrier. And end point detecting means for detecting a reflected signal by irradiating a sensor signal and analyzing the reflected signal to detect an end point of wafer polishing.

In the polishing table, one pad may be attached to the upper surface and the polishing table itself may be used. In the latter case, the polishing table may be used for physical polishing and lapping depending on the type of the surface plate.

In the present invention, the polishing platen is composed of a lens type having a predetermined radius of curvature for polishing a plane or convex or concave shape of a polishing object like a wafer. Concave or convex, so that any one can be detachably replaced, the carrier of the polishing head device corresponding to the polishing table can be configured to selectively mount a flat or convex or concave-type polishing object It is characterized by.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. In describing the embodiment, the polishing table is attached to the polishing table and the planar type wafer processing is exemplified.

2 is a configuration diagram of the CMP device according to the present invention, as shown in this,

The vibration base 520 and the vibrator 600 are fixed to one side of the inner bottom of the body 100 of the CMP device, and the polishing head device 200 is installed on the inner top of the body 100. The vibration table 510 is installed on the upper surface of the vibration base 520 to enable horizontal vibration through an oil film, and the vibration shaft of the vibrator 600 is connected to the side of the vibration table 510.

The servo motor device 400 is installed on the upper surface of the vibration table 510, and the base base 310 is installed at the upper end of the rotation shaft 410 of the servo motor device 400, and on the upper surface of the base base. The polishing table 300 is installed, and the polishing pad 320 is attached to an upper surface of the polishing table 300.

In addition, the present invention further comprises a polishing head moving means 700 for horizontally moving the polishing head device 200, and the polishing head moving means 700 to the outside of the polishing plate 300. The wafer is loaded horizontally, the loading or unloading of the wafer is performed through the moving means 700, and the wafer 201 mounted on the carrier 210 is transferred to the polishing plate through the moving means 700. And an end point detecting means 800 for detecting the reflected signal by detecting a predetermined sensor signal by exposing the sensor signal to the outside and analyzing the reflected signal.

Figure 3 is an exemplary view showing the configuration of the vibration means according to the present invention.

The vibration means, the vibration generator 600 for vibrating the vibration rod 610 in a direction orthogonal to the servo motor rotation axis 410 in a predetermined distance, and the side is connected to the end of the vibration rod 610 In addition, the servo motor device 400 is installed on an upper surface thereof, and a vibration table 510 is provided on a lower surface of which is slid through an upper surface of the vibration base 520 and an oil film.

The vibration base 520 is a base plate 521 fixed to the body 100, and is installed on the upper surface of the base plate 521 and the surface is capable of horizontal vibration through the vibration table 510 and the oil film In contact with the oil sealing kit 522, two support parts 523a, 523b which are installed upward at a predetermined distance from one side of the oil sealing kit 522 on the upper surface of the base plate * 521, and two support parts 523a. It is configured to include a guide rod 524 is fixed between the, 523b.

The vibration table 510 is fixedly installed downward at a position corresponding to between two support parts 523a and 523b of the vibration base 520, and the guide rod 524 is fitted to slide freely in an intermediate part. The fixing part 511 with a hole (not shown in figure) is formed and comprised.

An oil compressor 530 is installed at an outer side of the oil sealing kit 522, and an oil hose 531 connected to the oil compressor 530 is connected to a side surface of the lower plate of the vibration table 510, and the vibration table. The lower plate of the 510 has an oil hose 531 connected to a side thereof to receive oil, and a plurality of oil leak holes (not shown in the drawing) so that oil is supplied to the inside of the lower plate so that it can be finely discharged to the lower surface. Formed and configured.

Here, the configuration of the carrier 210, the motor 220 for rotating the carrier 210 and the cylinder 240 for moving the carrier 210 up and down is a technical configuration commonly used in the prior art in the present invention Detailed description of the description will be omitted.

In the present invention, the slurry supply means which is supplied onto the polishing pad through the hole of the polishing pad 320 is a part mentioned in the prior art and will be omitted.

Referring to the operation of the present invention configured as described above are as follows.

First, after mounting the wafer 201 on the lower surface of the carrier 210, the slurry is sufficiently supplied in advance to the upper surface of the polishing pad through the hole of the polishing pad (slurry should be continuously supplied while the wafer is in contact with the polishing pad). By operating the cylinder 240, the carrier 210 is pushed downward to contact the polishing pad 320 provided on the upper surface of the polishing plate 300 at a predetermined pressure, and the carrier is rotated at a predetermined speed. (There is a device for rotating the carrier (mainly a motor), and even if there is no separate device, there must be a structure that can rotate so that the carrier can also be rotated by friction when the surface rotates.)

Thereafter, the vibration generator 600, which is a linear reciprocating moving means, is moved forward and backward to oscillate the vibration table 510.

At the same time, when the servo motor device 400 is driven and rotated at a predetermined speed, the polishing plate 300 simultaneously rotates at low speed by the servo motor device 400 along with horizontal vibration by the vibration generator 600. Is done. The reason why the polishing motor 300 is rotated at a low speed by driving the servo motor device 400 is to allow the polishing pad 320 to be used evenly and at the same time to polish the entire surface of the wafer evenly. The wafer 201 is polished by the reciprocating motion, that is, the oscillating force of the polishing plate 300 in the horizontal direction by the driving.

When the vibration generator 600 is driven as described above, and the vibration rod 610 moves forward and backward, as shown in FIG. 4, the forward and backward movement force of the rod 610 is transmitted to the vibration table 510 as well. The fixed part 511 fixed to the vibration table 510 is linearly reciprocated by a predetermined distance under the guidance of the guide rod 524. At this time, the upper surface of the oil sealing kit 522 on the upper surface of the vibration base 520 of the vibration table 510 is made in surface contact, the oil supplied by the oil compressor 530 leaks and the vibration table 510 ) And an oil film is formed on the upper surface of the oil sealing kit 522 to generate sliding.

As a result, when the fixing part 511 linearly reciprocates along the guide rod 524, the vibration table 510 in which the fixing part 511 is installed also linearly reciprocates a predetermined distance, and thus the polishing surface 300 Is capable of linear reciprocating movement in a direction orthogonal to the carrier 210 and at the same time a low-speed rotational movement.

Therefore, as the carrier 210 of the polishing head is rotated, and the polishing plate 300 simultaneously performs a linear reciprocating motion and a rotational motion, the lower surface of the wafer 201 is uniformly polished. Here, linear reciprocating motion means horizontal vibration.

As described above, the present invention in the polishing process by linearly reciprocating (vibrating) a predetermined distance while slowly rotating the polishing surface 300 so that the polishing direction does not appear and the polishing pad 320 is evenly used. The slurry is uniformly supplied to the upper surface of the polishing pad and the polishing surface of the wafer through the holes of the polishing pad 320 without waste of the slurry by centrifugal force, and the temperature of the supplied slurry is also constant so that the polishing proceeds at a constant temperature gradient. The phenomenon is significantly reduced.

In addition, in the present invention, the polishing table 300 is linearly reciprocated so that a defect does not occur such that the wafer is separated from the polishing table of the conventional rotation type.

In addition, the present invention is configured to polish only one wafer 201 on the polishing plate 300 to reduce the overall size of the CMP device, and as shown in FIG. 5, the CMP device 500 is By providing a plurality of stages in multiple stages, it is possible to efficiently polish a larger number of wafers and to miniaturize the device.

On the other hand, compared to the conventional CMP device, the present invention can detect the end point of polishing by a simple method. To this end, the present invention installs a conveying apparatus 700 for horizontally conveying the polishing head apparatus 200, and transfers the conveying guide 710 of the conveying apparatus 700 to the cylinder 240 of the polishing head apparatus 200. Fix it). Then, the end point detection device 800 is installed in the body 100 to detect the reflection signal by irradiating a sensor signal to the wafer 201 on the side of the polishing table 300 to detect the end point of polishing.

In the end point detection method, the transfer apparatus 700 is driven to transfer the polishing head apparatus 200 to transfer the carrier 210 to the upper outside of the polishing plate 300. In other words, the lower surface of the wafer 201 mounted on the carrier 210 is partially exposed. Then, the end point detection device 800 is driven to irradiate the sensor signal to the wafer 201 mounted on the carrier 210 to detect the reflected signal, and then analyze it to detect the end point of polishing, that is, the end point. will be.

On the other hand, although not shown in the drawings, as another embodiment of the present invention, the polishing surface 300 has a predetermined radius of curvature for polishing a plane or convex or concave for polishing a polishing object like a wafer. It is configured in the form of a lens and is configured to be detachably replaceable in any one of the above three according to the kind of polishing object. This makes it possible to perform the polishing operation by selectively mounting only the concave polishing table or the convex polishing table as well as the polishing table (plane type) for wafer processing described in the above embodiments.

In this case, of course, the carrier of the polishing head apparatus is configured to selectively mount a planar or convex lens type or concave lens type polishing object corresponding to the polishing table. Since the polishing head carrier is to mount the polishing object by using a vacuum suction method or the like, the carrier may be configured so as to replace and install a carrier suitable for the shape and size of the polishing object.

Therefore, the structure in which the grinding | polishing operation | work is performed by a vibrating system like this invention is able to grind | polish the convex-type or concave-type polishing object which is difficult to process.

As described above, according to the CMP device according to the present invention, it is possible to improve the polishing operation efficiency while minimizing the amount of slurry used, it is possible to prevent the wafer from being separated from the polishing head during the polishing operation, The overall size of the device can be reduced as much as possible.

According to the present invention, the end point detection device is located on the outside of the surface plate, which eliminates the necessity of creating a window on the polishing pad (a pad with a window is expensive), thereby reducing the unit cost of the polishing pad and integrating the surface of the wafer. This enables accurate detection during EPD, thereby reducing over polishing time.

In addition, the polishing of the concave surface or the convex surface, which has not been polished by the conventional rotating method, can be performed by changing the shape of the surface plate concavely or convexly.

Claims (7)

CMP device comprising a polishing table, and a polishing head device for mounting a polishing object to rotate on the upper side of the polishing table and move up and down to bring the polishing object into contact with the polishing table at a predetermined pressure. To A polishing table linear reciprocating means for providing a main polishing force of the polishing object by linearly reciprocating the polishing table in a direction orthogonal to the polishing head device, and a polishing table rotating means for rotating the polishing table at a predetermined speed. Consists of more including The linear reciprocating means, A vibration generator for advancing the vibration rod back and forth a predetermined distance in a direction orthogonal to the polishing head device; A vibration table having a side portion connected to an end of the vibration rod and having the polishing surface seated and fixed on an upper surface thereof and moving back and forth by the vibration rod; CMP device, characterized in that the upper surface is in contact with the lower surface of the vibration table, but an oil film is formed and sliding, including a vibration base fixed to the body of the CMP device. delete The vibration base of claim 1, A base plate fixed to the body, It is installed on the upper surface of the base plate and the oil sealing kit and the surface contact to enable horizontal vibration through the vibration table and the oil film, A groove is formed at one side of the oil sealing kit of the upper surface of the base plate, and two support parts are installed upwardly at a predetermined interval in the groove; A guide rod fixed between two supports, In the vibration table, CMP device, characterized in that the fixing part is formed fixedly installed downward in the corresponding position between the two support of the vibration base and formed with a hole in which the guide rod is inserted to slide freely in the middle portion. The method of claim 3, wherein the CMP device, An oil compressor is installed at an outer side of the oil sealing kit, An oil hose connected to the oil compressor is connected to the side of the lower plate of the vibration table, The lower plate of the vibrating table is connected to the oil hose on the side is supplied with oil, the oil is supplied to the inside of the lower plate is a CMP characterized in that a plurality of oil leakage holes formed to be formed to flow out finely to the lower surface Device. The method of claim 1, wherein the CMP device, Polishing head conveying means for conveying the polishing head apparatus horizontally to expose a wafer; When the wafer conveyed by the transfer means is mounted on the polishing head is exposed, an end point detection device for detecting the end point of polishing by irradiating the sensor signal to the exposed wafer, and then detects and analyzes the reflected sensor signal; CMP device, characterized in that configured. The method of claim 1, The polishing platen rotating means is a servo motor device fixedly installed on an upper portion of the linear reciprocating moving means, A polishing table base is provided on an upper part of a rotary shaft of the servo motor device, and a polishing table is provided on an upper portion of the polishing table base, and a polishing pad is attached to an upper surface of the polishing table. The method of claim 1, The polishing plate, It is configured to be detachably replaceable either a planar type for wafer polishing or a convex lens type having a predetermined radius of curvature for polishing a polishing object in a convex lens shape or a concave lens shape for polishing a polishing object in a concave lens shape. , And a carrier of the polishing head device corresponding to the polishing table, so that the carrier of the polishing head device can selectively mount a polishing object of planar, convex, or concave lens type.

Images