JP2002093759A - Polishing system, method for producing semiconductor device using the system and semiconductor device produced by the method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polishing system realizing a high space efficiency and a high throughput by a simple arrangement. SOLUTION: The polishing system 1 comprises a cassette index section 100, a cleaning section 200, and a polishing section 300. On an index table 340 in the center of the polishing section, n chucks V1-V4 are provided and one carriage stage 350 and n-1 polishing stages are formed in correspondence with its positioning stopping position. A polishing arm (311, 321, 331) at each polishing stage is fixed with a polishing head hanging down from the forward end part of the arm and rotating at high speed. A not yet machined substrate carried in by means of the carriage stage 350 is polished n-1 times at each polishing stage (310, 320, 330) by index operation and carried out again from the carriage stage 350.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for polishing a substrate, and more particularly, to an index table for rotating and stopping a substrate held by a chuck at predetermined angles, and an index table assigned to a stop position of the index table. The present invention relates to a polishing apparatus having a polishing stage for polishing a substrate by carrying the substrate, and a transfer device for carrying the substrate into and out of the index table.

[0002]

2. Description of the Related Art A substrate polishing apparatus as described above has already been used as a polishing apparatus for a glass substrate, a quartz substrate, a semiconductor wafer substrate or the like. For example, JP-A-10-30
Japanese Patent No. 3152 discloses a polishing apparatus (referred to as a CMP apparatus) for precisely polishing a metal film on an interlayer insulating film on a semiconductor wafer substrate by a chemical mechanical polishing method (CMP method). In this polishing apparatus, as shown in FIG. 9, an index table T is divided into four regions, and a vacuum chuck for holding a semiconductor wafer substrate (hereinafter, referred to as a substrate) W is provided in each of the divided regions. Have been. The index table T is rotated and fed every 90 degrees, and four stages are provided at the determined stop positions corresponding to the division of the index table.

The four stages are shown in FIG.
As shown, the loading stage s₁And two polishing stays
S_Two, s_ThreeAnd unloading stage s_FourConsists of Polishing stay
S _Two, S_ThreeIs a region where the substrate W is polished, and the polished surface
Is provided. Polishing stage
Then, the vacuum chucked substrate W is rotated at high speed.
Then, press the polishing surface of the polishing head on this substrate
Work the surface flat. Loading stage s₁And unloading stay
S_FourAnd a loading robot for loading unprocessed substrates.
Unloading robot R that unloads processed substrates after finishing₁, R
_TwoAre provided independently of each other.

[0004] In the polishing apparatus, carrying the robot R ₁ is carrying a substrate raw to carry stage s _1, to position the index table T to the primary polishing stage s ₂ by 90 degrees rotation, the crude the primary polishing stage the index table T after processed is rotated 90 degrees by positioning the secondary polishing stage s _3, the secondary index table T after finishing polishing stage unloading stage s ₄ by 90 degrees rotation It is positioned, to unload the processed substrate unloading robot R _2. By repeating such operations sequentially, the index table T
Each time the rotation is stopped, a new unprocessed substrate is carried into the carry-in stage, and the processed substrate is carried out from the carry-out stage so that polishing can be performed continuously.

According to the polishing apparatus having such a configuration, for example,
Polishing time t per substrate _pOf the first polishing
And the polishing time at the second polishing stage is t_p
/ 2, and the substrate loading time t in the loading stage
_LAnd substrate unloading time t at the unloading stage_ULTogether
t_p/ 2, the index table
If the rotation positioning time is excluded as a minute term, continuous operation
At time t_p/ 2 can produce one board
Possible (hereinafter, the time for producing one substrate in this way)
The interval is called tact time).

[0006]

The substrate manufacturing apparatus is required to always have an improvement in productivity including the above-described polishing apparatus, and it is necessary to improve the number of substrates that can be processed within a certain period of time (referred to as throughput). It is an important technical issue.

[0007] Come with the above-mentioned polishing apparatus, as a technique for improving the left throughput of a conventional device configuration, the approach of polishing efficiency improvement by improving the polishing efficiency in the polishing stage to reduce the processing time t _p per one substrate is there. Specific examples include improvement of a polishing pad and a slurry (polishing liquid) in a polishing head, and an increase in a relative polishing rate by increasing the rotation speed of a chuck and a polishing head. Although the improvement of such basic technology has an important significance and is being brought to a certain effect, there is a problem that it is difficult to significantly improve the throughput only by this approach.

As another method for obtaining a high throughput, there is an approach for improving production efficiency by increasing the number of simultaneously polished polishing machines to improve production efficiency. Specifically, it is a method of increasing the number of polishing stages that can be simultaneously polished.
For example, the index table of the above-described conventional polishing apparatus is increased in size to increase the number of divisions, and a new polishing stage is provided for the increase in the number of divisions to constitute the polishing apparatus. According to this structure, the number of polishing stages by increasing the 2 → 3 → x, to shorten the tact time of substrate production in continuous operation to _{t p / 2 → t p /} 3 → t p / x be able to.

However, in such a method, the index table becomes large due to an increase in the number of polishing stages, and accordingly, there is a problem that the polishing apparatus becomes large in size and space efficiency is deteriorated. Further, two stages of the division number of the index table (loading stage s ₁ and extraction stage s ₄₎ are not contributing to the polishing process in the polishing apparatus, is low throughput in spite of the size of the entire polishing apparatus problems was there. Furthermore, independent robots are provided for the loading stage and the unloading stage, respectively, and are controlled, so that there is a problem that the number of constituent devices is large and the control is complicated.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems and problems, and has as its object to provide a polishing apparatus capable of realizing high space efficiency and high throughput with a simple apparatus configuration. It is an object of the present invention to provide a semiconductor device manufacturing method capable of manufacturing a semiconductor device at low cost by realizing the method, and a semiconductor device obtained by this manufacturing method.

[0011]

In order to achieve the above object, the present invention provides an index which has a chuck for holding a substrate on a table, stops the table from rotating at predetermined angles, and positions the chuck at a predetermined angular position. A table and a polishing stage having a polishing head for polishing a substrate allocated to the position of the positioned chuck are provided.The index table is rotated to position the substrate held by the chuck on the polishing stage, This is a polishing apparatus that performs polishing using a polishing head. Then,
The index table has at least two or more n chucks. At the stop position of the index table, n stages are formed corresponding to the n chucks positioned. The n stages carry out a processed substrate after polishing from the chuck, carry one new substrate before polishing into the chuck, and polish the substrate held by the chuck (n−
A new substrate is loaded into a chuck at a transfer stage, and is sequentially rotated and positioned on (n-1) polishing stages by an index table to perform (n-1) polishing operations. The polishing apparatus is configured so that the polished processed substrate is unloaded from the transfer stage.

The above-structured polishing apparatus has n (n ≧ 2) chucks on the index table, and has n stages corresponding to the n chucks at the positioning stop positions of the index table. One of the n stages is a transfer stage for carrying out the processed substrate from the chuck and carrying a new substrate before polishing into the chuck, and the other (n-1) stages are for transferring the substrate held by the chuck. This is a polishing stage for polishing. Then, the new substrate carried into the chuck in the transfer stage is rotationally fed by the index table, for example, as a first polishing stage → a second polishing stage →... → an (n−1) th stage. Polished at (n-1)
After being polished twice, the processed substrate is unloaded from the transfer stage.

According to the polishing apparatus having the above configuration, among the n stages provided in correspondence with the number of divisions of the index table, (n-1) polishing stages perform polishing, and The ratio of the number of polishing stages is (n
-1) / n. Thus, for example,
In a polishing apparatus provided with the same number of polishing stages as in the past, the index table can be made smaller and the entire apparatus can be made smaller.In a polishing apparatus having the same number of divided index tables, the polishing stage can be used without increasing the size of the apparatus. High throughput can be realized by increasing the number.
For example, in a polishing apparatus having a four-part index table, the conventional tact time t _p / 2 can be reduced to t _p / 3, and the production efficiency can be increased by a factor of 1.5. Therefore, it is possible to provide a polishing apparatus that achieves both high space efficiency and high throughput. The term "polishing head" as used herein refers to an assembly having a polishing member such as a polishing pad which is directly in contact with a substrate and performs polishing, and may be rotated by a rotary drive mechanism. , May not have a rotation drive mechanism.

The chuck in the above polishing apparatus is disposed on the upper surface of the index table and holds the substrate upward, and the polishing head is configured to polish the substrate positioned on the polishing stage from above. It is desirable. According to such a configuration, the polishing apparatus can be configured by using a polishing pad having a smaller diameter than the substrate, whereby the overall apparatus can be significantly reduced in size and a polishing apparatus with high space efficiency can be provided. In addition, since the polishing pad has a small diameter, high-speed rotation can be easily achieved, and polishing efficiency can be improved. Furthermore, according to such a configuration, when the surface of the polishing pad is dressed up with a pad dresser (also called a pad conditioner), the diamond abrasive grains detached from the dresser and adhered to the polishing pad are easily dropped. (In the case of a reverse configuration, diamond abrasive grains are likely to remain on the polishing platen), and the occurrence of scratches on the substrate can be suppressed.

The rotation time interval t _i of the index table is such that t _i ≧ t between the longest polishing time t _pMAX of the respective polishing times in the (n−1) polishing stages.
_The polishing apparatus is configured so as to have a relationship of _pMAX . The polishing process performed using the substrate polishing apparatus includes an ILD process for polishing an interlayer insulating film, a copper process and a tungsten process for polishing a wiring layer, and an ST for polishing a dielectric layer.
There are a wide variety of processes such as an I process, and depending on the process, the type and processing time of polishing performed in a plurality of polishing stages may be different. According to the polishing apparatus having the above structure, when the thus each polishing time differs by a plurality of polishing stages, always t _i ≧ during the rotation time interval t _i of the index table is the longest polishing time t _pMAX is set so as to satisfy the relationship _tpMAX ,
The index table rotates with or without the elapse of the longest polishing time. For this reason, for example, even if the polishing process that takes the longest polishing time is completed by detecting the end point, the index rotation is performed after the polishing process is surely completed, and a substrate of stable quality is produced. A polishing apparatus can be provided.

A single swing arm swingable with respect to the index table on the transfer stage, and a swing arm rotatably attached to the tip of the swing arm with respect to the swing arm. The polishing apparatus is provided with a transfer device having a first holder and a second holder attached to the rotating arm and holding the substrate. Then, when the processed substrate is positioned on the transfer stage, the swing arm and the rotation arm are operated to move the first holder to the positioning position of the processed substrate, thereby holding the processed substrate on the first holder. Rotating the rotating arm to carry the new substrate held by the second holder into the chuck of the transfer stage,
The polishing apparatus is configured by configuring the transfer device to operate the swing arm and the rotation arm to carry out the processed substrate held by the first holder.

According to such a configuration, the first holder (for example, the B clamp 37 in the embodiment) for holding the processed substrate on the rotating arm attached to the tip of the swing arm.
5b) and a second holder (for example, A clamp 375a in the embodiment) for holding a new substrate, and when the polishing process is completed and the processed substrate is positioned on the transfer stage, the transfer device is Processed substrate first
The new substrate received by the holder and already held in the second holder is loaded into the chuck on the transfer stage.
Therefore, it is possible to provide a polishing apparatus for quickly loading and unloading a substrate with a single transfer device having a simple configuration of one swing arm and one rotation arm.

Further, after the swing arm and the rotation arm are operated to start moving the first holder to the position for positioning the processed substrate, the swing arm and the rotation arm are operated to move the first holder to the first position.
The polishing apparatus is set by setting the substrate delivery time t _u before unloading the processed substrate held by the holder so as to have a relationship of t _i ≧ t _u with the rotation time interval t _i of the index table. With this configuration, the transfer of the substrate can be completed within the rotation time interval of the index table, and high throughput can be realized.

The first holder and the second holder in the transfer device
It is preferable that the holder is provided at the same distance from the rotation center of the rotation arm to constitute the polishing apparatus. According to such a configuration, the first holder is moved to the position of the processed substrate by operating the swing arm and the rotary arm, and the first holder is moved.
When the new substrate held by the second holder is positioned above the chuck after the holder receives the processed substrate, the rotating arm is simply rotated in place without swinging the swing arm. Can be positioned. Therefore, it is possible to provide a polishing apparatus having a transfer device that transfers a substrate at high speed with a simple device and a simple control structure.

Further, a semiconductor device manufacturing method includes a step of flattening the surface of a semiconductor wafer (substrate) by using the polishing apparatus configured as described above. According to such a manufacturing method, a semiconductor device can be manufactured at a lower cost than a conventional semiconductor device manufacturing method by using a high-throughput polishing apparatus.

The semiconductor device according to the present invention is manufactured by the semiconductor device manufacturing method. The semiconductor device manufactured by the above-described manufacturing method is manufactured at high throughput, and is a low-cost semiconductor device.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the present invention will be described below with reference to an example in which the present invention is applied to a CMP apparatus for precisely flattening a semiconductor wafer in a three-stage polishing process. As shown in FIG. 1 as a plan view of the overall configuration of the polishing apparatus 1, a
0, a wafer cleaning section 200, and a polishing section 300. Each section is partitioned to form a clean chamber. Note that an automatic opening / closing shutter may be provided between the respective rooms.

The cassette index section 100 includes a cassette (also called a carrier) C holding a plurality of wafers.
A wafer mounting table 120 for mounting _{1 to} C ₄ and an unprocessed wafer are taken out of the cassette and carried into the temporary washing stand 211 of the cleaning unit 200, and processed by the wafer cleaning unit 200 after polishing. And a first transfer robot 150 for storing the used wafers in a cassette.

The first transfer robot 150 is an articulated arm type robot having two articulated arms 153a and 153b. The first transfer robot 150 has a base 151 and a swivel table 152 capable of horizontal and vertical movements on the base. Two articulated arms 153a, 153b mounted on a table 152, an A-arm 155a and a B-arm 155 attached to the distal end of each articulated arm so as to be extendable and contractible with respect to each arm.
b (the B arm 155b is offset below the A arm 155a and overlaps vertically in the figure). A holding portion for mounting and sucking and holding a wafer is formed at the distal ends of the A arm 155a and the B arm 155b. The base 151 is provided with a linear moving device that can move horizontally along a linear guide 160 disposed on the floor.

For this reason, the first transfer robot 150 moves to the front of the target cassette along the linear guide 160, and horizontally turns and raises and lowers the swivel table 152 to move the cassette A.
The arm 155a or the B arm 155b is moved to a target slot height, and the multi-joint arm 153a and the A arm 155a, or the multi-joint arm 153b and the B arm 155b are actuated to move the tip of the A arm 155a or the B arm 155b. The unprocessed wafer in the target slot can be suction-held and taken out by the holding unit, or the processed wafer can be stored in the target slot.

Note that these two pairs of arms which are arranged offset in the vertical direction are functionally equivalent, and
Either one can be used for removal or storage, or only one arm can be used for both purposes. However, in the illustrated polishing apparatus, the unprocessed wafer is removed from the cassette by the lower B-arm 155b and washed. The latter processed wafer is set in the cassette by the upper A-arm 155a.

The wafer cleaning section 200 includes the first cleaning chamber 21
0, 2nd washing room 220, 3rd washing room 230, and drying room 2
40-chamber configuration, the polished wafer is the first
Cleaning chamber 210 → second cleaning chamber 220 → third cleaning chamber 230 →
The removal and cleaning of the slurry, the polishing solution, the abrasive wear powder, and the like which are sequentially sent as in the drying chamber 240 and adhered in the polishing section 300 are performed. For example, in the first cleaning chamber 210, both-side cleaning with a rotating brush, in the second cleaning chamber 220, surface pencil cleaning under ultrasonic vibration, in the third cleaning chamber, spinner cleaning with pure water, and in the drying chamber, drying under a nitrogen atmosphere. The processing is performed. The unprocessed wafer before the polishing process is carried into the wafer polishing unit 300 from the cassette index unit 100 through the wafer cleaning unit via the temporary washing stand 211 without passing through the cleaning process.

The polishing section 300 includes an index table 340 that is divided into four parts and is rotated and fed at 90 degrees by the operation of a stepping motor or the like.
An unprocessed wafer has been loaded and processed into the first polishing stage 310, the second polishing stage 320, the third polishing stage 330, and the index table provided so as to surround the index table from the outer periphery corresponding to the positioning stop position of 40. It comprises a transfer stage 350 for unloading the wafer.

Index table 340 divided into four parts
Of the each compartment, and the chuck V ₁ ~V ₄ for attracting and holding the wafer from the back surface is disposed exposed to the table top, with each chuck is supported rotatably in a horizontal plane in the index table 340 The high-speed rotation and the stop holding are freely mounted by driving means such as an electric motor and an air motor provided inside the index table 340. Note the diameter of the chuck V ₁ ~V ₄ is formed in a diameter slightly larger than the wafer diameter, and is grippable configure peripheral edge of the wafer held on the chuck.

Each of the three polishing stages of the first polishing stage 310, the second polishing stage 320, and the third polishing stage 330 is capable of swinging in the horizontal direction with respect to the index table 340 and vertically moving in the vertical direction. Polishing arms 311, 321 and 331 are provided. A polishing head (not shown) hanging from the polishing arm and rotatable at high speed in a horizontal plane is attached to a tip end of each polishing arm, and a polishing pad for flatly polishing the wafer by a relative rotation with respect to the lower end surface of the polishing head. have. In addition, pad dressers 317, 327, 337 for dressing up the surface of the polishing pad and pad exchange devices 318, 328, 338 for automatically exchanging the polishing pad are attached to each polishing stage.

The relative positions of the polishing arm, the chuck, the pad dresser, and the pad replacement device in each polishing stage are defined so as to be located on the swing radius of the polishing head at the tip of the polishing arm. Thus, for example, when performing polishing in the first polishing stage 310 is lowered to the polishing arm 311 with the polishing arm 311 is swung to move the polishing head on the chuck V _4, are rotated relative to the polishing head and the chuck Then, the polishing pad is pressed onto the wafer to perform the polishing process.

When the polishing process is completed and the polishing arm 311 is slightly raised, the index table 340 can be rotated. At this time, the polishing arm 311 is swung every predetermined number of times of polishing, and dressing is performed by the pad dresser 317 to correct clogging and irregularity of the polishing pad. The polishing pad 311 is further swung to move the polishing pad above the pad changing device 318, and the polishing pad is automatically changed by this device.

The pad dresser may be installed immediately adjacent to each chuck in the index table 340. According to such an arrangement, the polishing pad that protrudes from the outer periphery of the wafer during the polishing process can be dressed up during the polishing process, whereby the time required for polishing can be further reduced.

An arm position detector for detecting the swing angle position of the arm is attached to the polishing arm 311.
The polishing processing position and the dress-up position of the polishing arm 311 are detected. An end point detector that optically detects the polishing state of the wafer being polished is attached above the tip of the polishing arm or above the chuck of each polishing stage. It is configured to be detectable. The above configuration and operation are the same in the second polishing stage 320 and the third polishing stage 330.

On the transfer stage 350, a second transfer robot 360 and a third transfer robot 370 are provided. The second transfer robot 360 is an articulated arm type robot similar to the first transfer robot 150 described above.
Two articulated arms 363a, 363 slidably mounted on a swivel table 362 that can be operated horizontally and vertically.
b and an A-arm 365a and a B-arm 365b which are attached to the distal end of each articulated arm so as to be extendable and contractible. The A-arm 365a and the B-arm 365b are vertically offset from each other, and a holding portion for mounting and holding a wafer by suction is formed at the tip of each arm.

The third transfer robot 370 is provided with a swing arm 371 which is swingable in the horizontal direction and vertically movable in the vertical direction with respect to the index table 340, and a swing arm at a tip end of the swing arm. A rotating arm 372 that is mounted so as to freely rotate horizontally, and an A clamp 37 that is suspended at both ends of the rotating arm 372 and grips the outer peripheral edge of the wafer.
5a and a B clamp 375b.
The A-clamp 375a and the B-clamp 375b are disposed at the end of the turning arm at the same distance from the turning center of the turning arm 372. The state shown in FIG. 1 shows the standby posture of the third transfer robot, and the A clamp 37 shown in FIG.
Below the 5a and the B clamp 375b, an A temporary placing table 381 for placing an unprocessed wafer and a B temporary placing table 382 for placing a polished wafer are provided.

Therefore, the swing arm 371 of the third transfer robot 370 is swung, and the swing arm 372 is further rotated.
It is possible to move the A clamp 375a or B clamp 375b on the chuck V ₁ of the index table 340 by pivoting actuating and to lower the swing arm 371 in the position A clamp 375a or B
The wafer on the chuck can be clamped and received by the clamp 375b, or a new wafer can be placed and held on the chuck.

Since the polishing liquid containing slurry is attached to the polished wafer, an arm and a clamp for carrying in the wafer before polishing, and an arm and a clamp for carrying out the polished wafer. The A-arm 365a located above and the A-arm B vertically offset from the clamp are distinguished from the clamp, and the B-arm 365b located below is an unloading arm.
A clamp 375a is used for loading and B clamp 37
5b is defined as the unloading clamp.

Next, the operation of the polishing apparatus configured as described above will be described with reference to FIG.
In the state where a wiring groove is formed, a barrier layer 52 of TiN, TaN or the like is formed on the groove, and a copper conductive layer 53 is further formed thereon (hereinafter referred to as an unprocessed wafer), The substrate 53 and the barrier layer 52 are polished flat by three stages of a _first polishing process P ₁ , a second polishing process P ₂ , and a third polishing process P ₃ by a CMP method. Conductor wiring groove 5 as shown in FIG.
An example in which a Cu-CMP process for forming 3a is performed will be described.

In the second polishing process P ₂ and the third polishing process P ₃ , it is necessary to control the polishing end point.
The polishing process is terminated by the detection of the polishing end point by the end point detector. On the other hand, the primary polishing process P ₁ is a preceding polishing process of the secondary polishing process P ₂ , and it is not necessary to detect the end point. Accordingly, the polishing time in the first polishing process P ₁ and t _p1, t _p2 ± dt ₂ polishing end time in the secondary polishing process P ₂ and the third-order polishing P ₃ respectively, t _p3 ± dt ₃ and _{when, t p1> t p2 + dt} 2, t p1> as a t _p3 + dt ₃ sets the processed film thickness of each polishing.

[0041] Figure 3, the raw wafer W _d that is set in the cassette C ₁ cassette index portion 100, processed wafers W _p Nearby are sequentially polished with the polishing unit 300 shown in FIG. 2 (b), the wafer the flow of wafers to be cleaned treated with the cleaning unit 200 is housed in the cassette C ₄ of the cassette index part 100 is obtained denoted by the dotted arrow. The transfer robots 150, 360, 37
0 and the index table 340, chuck V ₁ ~V _4,
The operations of the polishing arms 311, 321, 331, the polishing head, and the like are controlled by a control device (not shown), and the control device controls these operations based on a preset control program.

[0042] First, when the polishing apparatus is started by polishing boot, the first transfer robot 150 is moved to the position of the cassette C _1, the swivel base 152 by a horizontal pivot and is raised and lowered operation and purpose of the B-arm 155b Arm 153b and B-arm 155
b is an elongated actuating the raw wafer W _d of the slot is held by suction by the holding portion of the B-arm 155b tip, pulled out the two arms is Chijimicho operated. Then, the swivel 152 is set to 18
0 ° pivoted actuated toward the wafer cleaning unit 200, placing the raw wafer W _d on washer temporary table 211 provided in the cleaning unit 200.

The second transfer robot 360 of the loading stage 350 to face each other across the wafer cleaning chamber 200, the raw wafer W _d is placed on the temporary placement table 211, the swivel deck 36
2 to turn the tip of the A-arm 365a toward the temporary washing stand 211, and the multi-joint arm 363a
And A arm 365a is extended actuated A arm tip to the suction holding the raw wafer W _d on washer temporary stand 211 holding part. When the unprocessed wafer is held, the multi-joint arm 363a and the A-arm 365a are reduced in length and the swivel table 362 is turned to invert, and the multi-joint arm 363a and the A-arm 365a are extended again to extend the unprocessed wafer. W _d is placed on the A temporary placing table 381.

[0044] When the raw wafer W _d is placed on the A temporary placement table 381, the third transfer robot 370 is lowered operating grip the raw wafer W _d by A clamp 375a, until the grip after a predetermined height It waits until the positioning of the index table 340 is completed at the standby position where the raising operation is performed (standby posture). Index table 340 is placed to be held by suction raw wafer the swing arm 371 and pivot arm 372 swinging operation movement and is pivoted operating Stopping positioned on the chuck V _1. The third transfer robot 370 is raised after unclamping, the swing arm 371 and pivot arm 372 swinging operation movement and is rotated operates the following raw wafer W _d gripped by the A clamp 375a, predetermined height Wait until the next index operation at the standby position.

Thereafter, the polishing in the polishing section 300 is started. Figure 4 is raw wafer W _d carried into loading stage 350 in this manner is first polishing stage 310
To the second polishing stage 320, the third polishing stage 330
Is shown as a flow chart from the transfer stage 350 through the transfer stage 350, and the polishing process in each polishing stage will be described below with reference to FIG.

The unprocessed wafer W _d is held by suction on the chuck V ₁ , and the third transfer robot moves the index table 34.
When retracted from above the 0 (step S10), and an index table 340 clockwise by 90 degrees rotation operation (clockwise) in step S20, (V ₄ position in the figure) the raw wafer W _d first polishing stage 310 Position. At this time, the polishing arm 311 is simultaneously swung to move the polishing head onto the unprocessed wafer.

[0047] When the index table stops positioning the polishing pad of the polishing head bottom is pressed onto the wafer polishing arm 311 is lowered along with the rotated at a high speed and a polishing head and the chuck V ₁ proceeds to step S30, for example, in opposite directions, the primary polishing process P ₁ performs. During polishing, the polishing arm 311 is swung in a very small range so that the polishing pad reciprocates between the center of rotation of the wafer and the outer peripheral end while supplying slurry from the axis of the polishing head to move the wafer. Polish uniformly and flat. New raw wafers during the transfer stage 350 in the primary polishing process is carried on the chuck V ₂ by the third transfer robot 370.

The primary polishing process P ₁ is the time control as mentioned above, when a predetermined polishing time t _{p 1} has elapsed (Step S35) The polishing stops the polishing arm 311 is raised (step S40 ), And proceed to step S50.

In step S50, the index table 340 is rotated 90 degrees clockwise again, and the wafer after the _first polishing P1 is moved to the second polishing stage 320.
To position (V ₃ position in the drawing). At this time, the polishing arm 321 is simultaneously swung to move the polishing head onto the wafer. Then, proceeding to step S60, the polishing arm 321 is lowered, and the first polishing process P _{1 is performed.}
The secondary polishing process P ₂ performs the same operation as the. In this case primary lapping of the raw wafer held by the chuck V ₂ in the first polishing stage 310 is carried out concurrently. When the secondary polishing process P ₂ is the end point detection process, processed film thickness which is detected by the endpoint detector it is determined to have decreased to a predetermined thickness that has been set in advance (step S65)
Then, the polishing arm 321 is raised to stop the polishing (step S70).

At this time, in the first polishing stage, the primary polishing process P ₁ is still continued, and the index table 340 cannot be rotated with the end of the secondary polishing process P ₂ . Therefore, in step S75, the polishing of the first polishing stage is stopped, and it is confirmed whether or not the primary polishing is completed. When the primary polishing is completed, the process proceeds to step S80, and the primary polishing is performed. When the polishing is being continued, the process returns to step S70 and the above confirmation is repeated.

In step S80, the index table 340 is rotated 90 degrees clockwise again, and the wafer after the _second polishing P2 is moved to the third polishing stage 330.
To position (V ₂ position in the figure). The polishing arm 331 lowers the tertiary polishing P ₃ performed by the operation similar to that described above (step S90).

In step S80, the wafer after the _first polishing P1 is moved to the second polishing stage 320.
A new unprocessed wafer is positioned on the first polishing stage 310, and in step S90, the first polishing stage 310
, The new unprocessed wafer held by the chuck V ₃ is subjected to the first polishing, and the wafer held by the chuck V ₂ in the second polishing stage 320 is subjected to the second polishing.

The third polishing process P ₃ is also an end point detection process similar to the _second polishing process P ₂ , and it is determined that the processed film thickness detected by the end point detector has decreased to a predetermined film thickness set in advance. (Step S95), the polishing arm 331 is raised to stop the polishing (Step S100). Then, in step S105, it is checked whether the primary polishing has been completed. If the primary polishing has been completed, the process proceeds to step S110. If the primary polishing has been continued, the process proceeds to step S100. Return and repeat the above checks.

In step S110, the index table is again rotated clockwise by 90 degrees and the third polishing P
₃ wafer ended to position the transport stage 350 (V ₁ position in the drawing). Index table 34
When 0 is positioned and stopped, both the third transfer robot 370 unloads the processed wafer W _p that polishing has been completed by the swing arm 371 and pivot arm 372 swinging operation movement and rotates operated (step S120), the following raw wafer W _d and carried onto the chuck V ₁ is attracted to and held by the chuck V _1, returns to step S10.

[0055] FIG. 5 is a third unloading processed wafers W _p by the transport robot 370, and showed a loading operation status of the raw wafer W _d detail. First, FIG.
When the position of the index table 340 is stopped, the third transfer robot 370 at the standby position swings the swing arm 371 and swings the rotation arm 372 as shown by an arrow in the drawing. It is nothing to move the grasped non B clamp 375b on the chuck V ₁ (Figure 5 (b)). At this time, A clamp 375
The next unprocessed wafer _Wd is already gripped by a.

[0056] Then, the third transfer robot 370 grasps the processed wafers W _p in B clamp 375b and lowering operation, after slightly increased actuation, neat as shown by an arrow in FIG. 5 (b) In position only the rotating arm 372 is 18
A horizontal rotation of 0 degrees, the A clamp 375a
Position it on ₁ (Fig. 5 (c)). Then, the mounted holding a raw wafer which has been grasped by the A clamp 375a descends again actuated to chuck V _1. Next, the swing arm is raised and the swing arm 371 and the rotation arm 372 are moved.
5A, the A clamp 375a is moved above the A temporary placing table 381, and the B clamp 375b is moved above the B temporary placing table as shown by arrows in FIG. (d)). At this time, a new unprocessed wafer _Wd has already been carried in and placed on the temporary storage table 381 by the second transfer robot 360.

After the movement positioning, the third transfer robot 370
Operates to move the processed wafer W _pTo B positioning table 3
82, and at the same time, a new
Unprocessed wafer W_dIs gripped by the A clamp 375a.
You. Then, while holding a new unprocessed wafer,
To the next index operation in this standby position.
Wait at.

[0058] Thus, the third transfer robot 370 is only a small lifting operation and a turning operation of the turning arm carrying onto the index table of the carry-out and raw wafer W _d of processed wafers W _p on the index table Done at
Further, since the placement of the processed wafer on the temporary placing table and the gripping of the unprocessed wafer are performed by one raising / lowering operation, the loading / unloading of the wafer can be completed in a very short time. Therefore, a series of loading / unloading operations shown in FIGS. 5A to 5D are completed within a time shorter than the first polishing processing time _tp1 .

The transfer stage 350 has a chuck (V
A device for cleaning _{1 to} V ₄ ) may be provided. In this case, B
By swinging the swing arm 371 after grasping the machined wafer W _p clamp 357b is moved to the standby position performs the chuck cleaning after, the transfer stage the raw wafer W _d that is then gripped by the A clamp 375a 350 Is preferably mounted on the chuck.

[0060] When the processed wafers W _p is placed on B temporary carrying stand 382 third transfer robot 370 is stopped at the standby position, the second transfer robot 360 is swivel base 362, the articulated arm 363b and the B-arm 365b operate is not the processed wafers W _p on B temporary placement table 382 is held by suction by the holding portion of the B-arm tip, turning actuates the swivel base 362, articulated arm 363b and the cleaning unit the B arm 365b is by extending action The processed wafer _Wp is placed at the inlet 216 of the washing machine 200.

In the cleaning section 200, both-side cleaning with a rotating brush is performed in the first cleaning chamber 210, surface pencil cleaning under ultrasonic vibration in the second cleaning chamber 220, spinner cleaning with pure water in the third cleaning chamber 230, and drying. A drying process is performed in a chamber 240 under a nitrogen atmosphere. Then, this finished product wafer that has been cleaned in the is removed from the cleaning unit 200 by the A-arm 155a of the first transfer robot 150 in the cassette index portion 100 is accommodated in the specified slot of the cassette C _4.

In the above, the progress from the stage where the unprocessed wafer _Wd is processed in each stage until it is stored as a processed wafer has been described in time series. The wafer is loaded,
A new processed wafer is unloaded each time the index table is rotated. FIG. 6 shows this state as a flow of a wafer, in which the time axis is taken on the vertical axis, and the progress of each wafer from the first to the sixth wafer is arranged on the horizontal axis. Each step interval in the vertical direction in the figure is a rotation interval of the index table, each wafer is unloaded from the cassette C ₁ for each rotation interval of the index table, the first sheet after the processing is completed rotation of the index table finished product of the wafer is accommodated in the cassette C ₄ for each interval. The rotation interval of the index table is defined by the polishing time divided into three stages. In the present embodiment, completed wafers are continuously produced almost every primary polishing time interval.

[0063] In the above-embodiment described, polished raw wafer is carried into the chuck V ₁ of the on the transfer stage, a three-step polishing stage is stopped rotating by 90 ° the index table 340 clockwise After the processing, the index table 340 is further rotated 90 degrees clockwise (total 360 degrees), and the example is disclosed in which the index table 340 is positioned on the transfer stage and unloaded. May be rotated 270 degrees counterclockwise when returning to the transfer stage 350. According to such a configuration, an expensive joint such as a swivel joint (also referred to as a rotary joint) is used to connect a vacuum pipe, an electric wiring, a pneumatic pipe, and the like which are arranged to connect the index table and the apparatus main body. There is no need to use it, and the polishing apparatus can be configured at low cost.

The polishing stages from the first polishing stage to the third polishing stage are functionally equivalent, and
Which one is the first and which is the third can be sequentially changed according to the processing target, the arrangement of the devices of other devices, and the like. That is, the rotation direction of the index table 340 is not limited to the clockwise direction. For example, in the polishing apparatus illustrated in the embodiment, the unprocessed wafer loaded on the transfer stage 350 is transferred from the transfer stage 350 to the third polishing stage. 3
30 → second polishing stage 320 → first polishing stage 31
It may be one which is polished counterclockwise and carried out like 0.

Further, in the embodiment, the case where two end points are detected in the Cu-CMP process is exemplified. However, the present invention is not limited to such a use, and the present invention is not limited to such a process as an interlayer insulating film processing process or an STI process. In addition to the simple wafer processing, the present invention can be similarly applied to a processing process for a quartz substrate, a glass substrate, a ceramic substrate, or the like. Further, each polishing stage may be defined by a polishing time, or may be defined by detecting an end point in all the polishing stages and completing polishing in all the polishing stages.

As described above, by performing polishing with three stages of polishing using the index table 340 divided into four parts as described in the prior art, it is possible to obtain a high throughput without increasing the size of the apparatus. An apparatus has been disclosed. On the other hand, in the case where the polishing is performed with the two-stage polishing stage as in the related art, the index table 346 can be reduced in size as shown in FIG. 7A, thereby providing a space-saving polishing apparatus. be able to.
Also, as shown in FIG.
If a configuration is adopted in which four stages of polishing stages are provided by dividing 7 into five parts, the size of the device will increase somewhat with an increase in the table diameter, but a polishing device capable of obtaining approximately twice as high throughput as the conventional one is provided. can do.

Next, an embodiment of a method for manufacturing a semiconductor device according to the present invention will be described. FIG. 8 is a flowchart showing a semiconductor device manufacturing process. When the semiconductor manufacturing process is started, first, in step S200, an appropriate processing step is selected from the following steps S201 to S204, and the process proceeds to any one of the steps.

Here, step S201 is an oxidation step of oxidizing the surface of the wafer. Step S202 is CV
C to form insulating film and dielectric film on wafer surface by D
This is a VD process. Step S203 is an electrode forming step of forming electrodes on the wafer by vapor deposition or the like. Step S2
Reference numeral 04 denotes an ion implantation step of implanting ions into the wafer.

After the CVD step (S202) or the electrode forming step (S203), the process proceeds to step S205. Step S205 is a CMP process. In the CMP process, the polishing apparatus according to the present invention performs planarization of an interlayer insulating film, polishing of a metal film on the surface of a semiconductor device, formation of a damascene by polishing of a dielectric film, and the like.

The CMP step (S205) or the oxidation step
After (S201), the process proceeds to step S206. Step S
206 is a photolithography step. In this step, a resist is applied to the wafer, a circuit pattern is printed on the wafer by exposure using an exposure device, and the exposed wafer is developed. Further, in the next step S207, portions other than the developed resist image are removed by etching.
Thereafter, the resist is removed, and this is an etching step of removing unnecessary resist after etching.

Next, it is determined in step S208 whether all necessary processes have been completed, and if not, step S2
Returning to step 00, the previous steps are repeated to form a circuit pattern on the wafer. If it is determined in step S208 that all steps have been completed, the process ends.

In the method of manufacturing a semiconductor device according to the present invention, since the polishing apparatus according to the present invention is used in the CMP process, the throughput of the CMP process is improved. As a result, there is an effect that a semiconductor device can be manufactured at a lower cost than a conventional semiconductor device manufacturing method. Note that the polishing apparatus according to the present invention may be used in a CMP step of a semiconductor device manufacturing process other than the semiconductor device manufacturing process. Further, a semiconductor device manufactured by the semiconductor device manufacturing method according to the present invention is manufactured at a high throughput, so that it is a low-cost semiconductor device.

[0073]

As described above, according to the present invention, there is provided a polishing apparatus including an index table and a polishing stage having a polishing head, and a polishing apparatus for rotating and positioning the index table to polish a substrate held on a chuck by the polishing head. In the index table, n (n ≧ 2)
Is provided, and one transfer stage and (n-1) polishing stages are provided at a stop position of the index table, and a new substrate is loaded into the chuck on the index table at the transfer stage, and Thus, the polishing apparatus is sequentially rotated and positioned on (n-1) polishing stages, polished (n-1) times, and the polished processed substrate is unloaded from the transfer stage.

According to the polishing apparatus having the above structure, (n-1) of the n stages provided corresponding to the number of divisions of the index table can be used as the polishing stage, and the number of stages can be reduced. The ratio of the number of polishing stages
(n-1) / n. For this reason, in a polishing apparatus provided with the same number of polishing stages as in the related art, the index table can be made smaller and the entire apparatus can be made smaller.In a polishing apparatus having the same number of divided index tables, the apparatus can be increased without increasing the size. High throughput can be realized by increasing the number of polishing stages. Therefore, it is possible to provide a polishing apparatus that achieves both high space efficiency and high throughput.

The polishing apparatus is arranged such that the chuck is disposed on the upper surface of the index table, the substrate is held upward, and the polishing head is configured to polish the substrate positioned on the polishing stage from above. Can be greatly reduced in size to provide a polishing apparatus with high space efficiency. In addition, since the polishing pad has a small diameter, high-speed rotation can be easily achieved, the polishing efficiency can be improved, and a higher throughput can be obtained.

The rotation time interval t _i of the index table is such that t _i ≧ t between the longest polishing time t _pMAX of the respective polishing times in the (n−1) polishing stages.
_By configuring the polishing apparatus to have a relationship of _pMAX , for example, the polishing process that is the longest polishing time,
Even in the case where the process is terminated upon detection of the end point, the indexing operation is performed after the polishing process is surely terminated, so that a polishing apparatus for producing a substrate of stable quality can be provided.

Further, one swing arm swingable with respect to the index table on the transfer stage, and a swing arm rotatably attached to the tip of the swing arm with respect to the swing arm. A polishing apparatus comprising a transfer device having a first holder and a second holder attached to the rotating arm and holding the substrate, wherein when the processed substrate is positioned on the transfer stage, the swing arm and Activating the rotating arm to move the first holder to the positioning position of the processed substrate, holding the processed substrate on the first holder, and rotating the rotating arm to rotate the new substrate held on the second holder Is transported into the chuck of the transport stage, the swing arm and the rotating arm are operated, and the transport device is configured to transport the processed substrate held by the first holder, thereby forming a polishing device. According to such a configuration, when the polishing processing is completed and the processed substrate is positioned on the transfer stage, the transfer device receives the processed substrate by the first holder and newly holds the processed substrate by the second holder. The substrate can be loaded into the chuck on the transfer stage. Therefore, it is possible to provide a polishing apparatus for quickly loading and unloading a substrate with a single transfer device having a simple configuration of one swing arm and one rotation arm.

Further, after the swing arm and the rotation arm operate and the first holder starts to move to the positioning position of the processed substrate, the swing arm and the rotation arm operate to move the first holder to the first position.
The polishing apparatus is set by setting the substrate delivery time t _u before unloading the processed substrate held by the holder so as to have a relationship of t _i ≧ t _u with the rotation time interval t _i of the index table. With this configuration, the transfer of the substrate can be completed within the rotation time interval of the index table, and high throughput can be realized.

The first holder and the second holder in the transfer device
It is preferable that the holder is provided at the same distance from the rotation center of the rotation arm to constitute the polishing apparatus. According to such a configuration, the first holder is moved to the position of the processed substrate by operating the swing arm and the rotary arm, and the first holder is moved.
When the new substrate held by the second holder is positioned above the chuck after the holder receives the processed substrate, the rotating arm is simply rotated in place without swinging the swing arm. Can be positioned with
It is possible to provide a polishing apparatus having a simple apparatus and a transfer apparatus for quickly transferring a substrate with a control configuration.

The method of manufacturing a semiconductor device including the step of flattening the surface of a semiconductor wafer (substrate) using the polishing apparatus configured as described above allows the use of a high-throughput polishing apparatus. In addition, a semiconductor device can be manufactured at a lower cost than a conventional semiconductor device manufacturing method. Further, the semiconductor device manufactured by the semiconductor device manufacturing method according to the present invention is manufactured at a high throughput, so that it is a low-cost semiconductor device.

[Brief description of the drawings]

FIG. 1 is a top view showing a configuration of a polishing apparatus according to the present invention.

FIG. 2 is a cross-sectional view illustrating a polishing process of a semiconductor wafer according to an embodiment of the present invention. Among them, FIG. (A) shows a wafer state before polishing processing, and (b) shows a wafer state after polishing processing.

FIG. 3 is a top view showing a wafer processing step in the polishing apparatus according to the present invention.

FIG. 4 is a flowchart showing a polishing process in the polishing apparatus.

FIG. 5 is an explanatory diagram illustrating an operation state of a transfer robot in the polishing apparatus.

FIG. 6 is an explanatory diagram showing a flow of a wafer in the polishing apparatus.

FIG. 7 is an explanatory view showing another embodiment of the polishing apparatus according to the present invention.

FIG. 8 is a flowchart of a semiconductor device manufacturing method according to the present invention.

FIG. 9 is a perspective view showing a configuration of a conventional polishing apparatus.

FIG. 10 is an explanatory view showing a stage configuration of a conventional polishing apparatus.

[Explanation of symbols]

S205 CMP process (step planarizing the semiconductor _{wafer) V 1, V 2, V} 3, V 4 Chuck W wafer (W _d raw wafers, W _p processed wafer, substrate) 1 polishing apparatus 310, 320, 330 polishing Stage 340, 346, 347 Index table 350 Transfer stage 370 Third transfer robot (transfer device) 371 Swing arm 372 Rotating arm 375a A clamp (second holder) 375b B clamp (first holder)

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3C058 AA09 AA18 AB03 AB04 BA02 BA09 CB03 CB05 CB09 DA17 5F031 CA02 CA05 FA01 FA11 FA13 FA15 GA08 GA43 GA44 GA47 GA48 GA50 GA54 HA13 MA22

Claims (8)

[Claims] An index table having a chuck for holding a substrate as a member to be polished on a table, rotating the table at predetermined angles and positioning the chuck at a predetermined angular position; and the positioned chuck. A polishing stage having a polishing head for polishing the substrate, the polishing head being assigned to a position corresponding to the position of the substrate, and rotating the index table to position the substrate held by the chuck on the polishing stage; In the polishing apparatus for performing polishing using, the index table has at least two or more n chucks, and at the stop position of the index table, corresponding to the n chucks positioned, polishing Unloading the processed substrate from the chuck after processing and a new substrate before polishing And one transfer stage for carrying said chuck,
Polishing the substrate held by the chuck (n-
1) the polishing stages, and the new substrate is carried into the chuck in the transfer stage, and is sequentially rotated and positioned by the index table to the (n-1) polishing stages. (N-1) The polishing apparatus, wherein the polished substrate that has been polished a number of times is carried out of the transfer stage. 2. The apparatus according to claim 1, wherein the chuck is disposed on an upper surface of the index table and holds the substrate upward, and the polishing head polishes the substrate positioned on the polishing stage from above. The polishing apparatus according to claim 1. 3. The rotation time interval t _i of the index table is set to t _i between the longest polishing time t _pMAX of the respective polishing times in the (n-1) polishing stages.
_3. The polishing apparatus according to claim 1, wherein the polishing apparatus is set to have a relationship of ≧ t _pMAX . 4. 4. A swinging arm which is swingable with respect to the index table, and a tip of the swinging arm is rotatably attached to the transfer stage with respect to the swinging arm. A transfer device comprising: a rotation arm; a first holder and a second holder attached to the rotation arm and holding the substrate; wherein the transfer device is configured to transfer the processed substrate to the transfer stage. When the positioning is performed, the swing arm and the rotating arm are operated to move the first holder to a positioning position of the processed substrate, and the processed substrate is held by the first holder. The moving arm is rotated to carry the new substrate held by the second holder into the chuck of the transfer stage, and the swing arm and the rotating arm are operated to move the first holder. The polishing apparatus according to claims 1 to 3, characterized in that for unloading the processed substrate held. 5. The swing arm and the rotation arm operate after the swing arm and the rotation arm operate and the first holder starts to move to the positioning position of the processed substrate. The substrate delivery time t _u before unloading the processed substrate held by the first holder is
5. The polishing apparatus according to claim 4, wherein the polishing table is set to have a relationship of t _i ≧ t _u with respect to the rotation time interval t _i of the index table. 6. 6. The polishing apparatus according to claim 4, wherein the first holder and the second holder are provided at the same distance from a rotation center of the rotation arm. 7. The semiconductor wafer according to claim 1, further comprising a step of flattening the surface of the semiconductor wafer by using the polishing apparatus according to claim 1. Semiconductor device manufacturing method. 8. A semiconductor device manufactured by the semiconductor device manufacturing method according to claim 7.