JP2002110598A - Cmp apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an apparatus which can hold a mix ratio of a polishing mixture solution always at a predetermined value, and can perform polishing operation with a good accuracy without using non-production wafer for confirmation of a processing rate to thereby improve a rate of operation in the apparatus and improve a productivity in a polishing step. SOLUTION: A processing solution dropping part, which has a plurality drop ports arranged dense from which a plurality of sorts of processing solutions are dropped on a platen, is formed at a tip end of a processing solution supply piping, so that the plurality of sorts of processing solutions drop from the drop ports into a platen rotation direction onto an upstream vicinity of a processing point of a wafer to be polished. Thereby since the processing solutions reach the processing point with a mixture ratio of the plurality of sorts of processing solutions held at a predetermined value, accurate polishing can be realized without using a non-production wafer for confirmation of a processing rate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a chemical mechanical polishing apparatus (hereinafter, referred to as a CMP apparatus) for polishing a semiconductor wafer chemically and mechanically.

[0002]

2. Description of the Related Art In a conventional CMP apparatus, for example, a wafer is polished by a method as shown in FIG. In FIG.
The CMP apparatus mainly comprises a rotatable surface plate 1 and a platen 1
And CMP processing liquid supply pipes 2a and 2b arranged in close proximity to the center part. CMP processing liquid supply piping 2
The tips of a and 2b are CMP processing liquid supply ports 3a and 3b.

When polishing the wafer 100, the platen 1 rotates in the direction indicated by 4 in FIG.
Two types of processing liquids respectively supplied from 2b are dropped directly from the CMP processing liquid supply ports 3a and 3b to the center of the platen 1. The working fluid is diffused on the surface plate in five directions by the rotation of the surface plate 1. The wafer 100 is chemically and mechanically polished by the mixed processing liquid having reached the processing point 6 in this manner.

[0004]

SUMMARY OF THE INVENTION As described above, the conventional C
In the MP device, the two types of processing liquids are dropped by the centrifugal force accompanying the rotation of the surface plate 1 to reach the processing point 6 of the wafer 100 because the two types of processing liquid dropped on the center of the surface plate 1 are diffused. Since the properties of the respective liquids, for example, if they are abrasive liquids, the particle diameters of the respective liquids are different, the mixing ratio of the mixed liquid at the time of reaching the processing point 6 is different from the state in which the mixed liquid is initially dropped on the surface plate 1. Will be different.

Further, the mixing ratio of the mixed processing fluid at the processing point 6 varies depending on the elapsed time after the start of the dropping, so that the CMP processing speed for the wafer 100 varies.

Therefore, in response to the fluctuation of the processing speed,
In order to maintain processing accuracy, the wafer must be processed while confirming the processing speed by performing CMP processing on the processing speed confirmation wafer, which is a non-production wafer, for each wafer or for each lot. Did not. For this reason, the number of unnecessary steps increases, the operation rate of the CMP apparatus decreases, and the confirmation wafer, which is a non-production wafer, is replaced with a C wafer.
Since the work of confirming the processing speed by PM processing is required, the wafer polishing step by the conventional CMP apparatus is a step with extremely low productivity.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and an object of the present invention is to always maintain a mixing ratio of a working liquid for polishing at a predetermined ratio to check a working speed. Provided is a CMP apparatus that can always perform high-precision polishing without using a non-production wafer for polishing, thereby improving the operation rate of the apparatus and improving the productivity of the polishing process. It is to be.

[0008]

In order to achieve the above object, a feature of the invention of claim 1 is that a plurality of types of processing liquid are supplied and dropped from a processing liquid supply pipe on a rotating platen to be polished. In a CMP apparatus that chemically and mechanically polishes the surface of a wafer to be polished by contacting, the plurality of types of processing liquids are dropped onto the surface plate at the tip of the processing liquid supply pipe. That is, a lower portion of a processing droplet having a plurality of arranged dropping ports is formed.

In the second aspect of the invention, the plurality of dropping ports are opposed to the lower part of the processing droplet in the vicinity of the upstream of the processing point of the wafer to be polished with respect to the rotation direction of the surface plate. It is characterized by being arranged as follows.

A feature of the invention according to claim 3 is that, when the processing point of the wafer to be polished oscillates, a mechanism for keeping a constant distance between the lower portion of the processing droplet and the processing point is provided. It is in.

According to a fourth aspect of the present invention, the mechanism is characterized in that the lower part of the processing droplet is integrated with a support mechanism for oscillating a processing point of the wafer.

According to the present invention, chemical-mechanical polishing is performed by bringing a film formed for manufacturing an integrated circuit on a Si wafer into contact with a rotating platen on which a plurality of types of working liquids are dropped. At this time, a plurality of types of CMP processing droplets having a plurality of processing droplet lower ports are set at a point near the upstream of the platen at the processing point, and a plurality of types of processing liquid are supplied from the plurality of processing droplet lower ports onto the surface plate. To perform a CMP process on the Si wafer. At this time, the dropped plural types of CMP processing liquid always reach the processing point with a constant mixing ratio, so that the processing speed does not fluctuate.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing a configuration of a CMP apparatus according to a first embodiment of the present invention. However,
The same parts as those in the conventional example will be described with the same reference numerals.

The CMP apparatus has a rotatable platen 1 and CMP processing liquid supply pipes 2a and 2b arranged close to the surface plate 1. The CMP processing liquid supply pipes 2a and 2b
A lower portion 7 of the CMP processing droplet is formed at a portion facing the surface plate 1 at the front end of the substrate. In addition, the lower part 7 of the CMP processing droplet
Is located at the point where the CMP processing liquid supply pipes 2a and 2b are bent in an L-shape.

FIG. 2 shows the lower portion 7 of the CMP processing droplet shown in FIG.
It is the perspective view which showed the example of the detailed structure of.

The lower part 7 of the CMP processing liquid droplet has a plurality of processing liquid droplet lower ports 8a at a right angle in the axial direction of a pipe part communicating with the CMP processing liquid supply pipe 2a, and a short pipe 2c having a closed end.
Are connected in a comb shape with a predetermined distance therebetween.
At a right angle in the axial direction of the pipe portion communicating with the MP processing liquid supply pipe 2b, a plurality of processing liquid drop ports 8b are provided in the axial direction, and a plurality of short pipes 2b whose ends are closed are connected in a comb shape with a predetermined distance therebetween. ing.

The CMP working liquid supply pipes 2a, 2b are arranged so that these short pipes 2a, 2b are alternately and closely arranged.
The connection position for 2b is shifted. The processing droplet lower ports 8a and 8b of the processing droplet lower part 7 are distributed and arranged so as to extend from the inner peripheral portion 20 to the outer peripheral portion 10 of the locus of the processing point 2 on the surface plate 1.

Next, the operation of this embodiment will be described.
When polishing the wafer 100, the platen 1 rotates in the direction indicated by 4 in the figure, and two types of processing liquid are supplied to the CMP processing liquid supply pipe 2.
a, 2b, flow into the comb-shaped pipes 2c, 2d arranged below the CMP processing liquid drop 7 and drop onto the surface plate 1 from a large number of processing liquid drop openings 8a, 8b.

At this time, the pipes 2a and 2b are closely arranged,
Therefore, since a large number of processing liquid drop openings 8a and 8b are also arranged closely, when two types of processing liquid are dropped on the surface plate 1, they are sufficiently mixed. Since the lower part 7 of the CMP processing droplet is located on the upstream side close to the processing point of the wafer 100 to be processed, the two types of processing liquids are mixed and reach the processing point of the wafer 100 immediately before the mixing ratio does not change. 100 is chemically and mechanically polished.

Incidentally, the lower part 7 of the CMP processing droplet is
Between the two trajectories 10 and 20 during which two types of machining fluids are mixed and spread.

According to the present embodiment, two types of working liquids are supplied from the large number of working liquid drop openings 8a and 8b which are closely arranged.
The two types of processing liquids are uniformly mixed because the liquid is dropped immediately upstream of the upper processing point 6, and the processing liquid reaches the processing point 6 while the mixing ratio does not change. Therefore, the CMP processing speed of the wafer 100 is kept constant. , And the processing accuracy can be improved. By improving the processing accuracy, it is not necessary to omit the operation of checking the CMP processing speed for each wafer or each lot, so that the operation rate of the CMP apparatus can be improved. In addition, the process for checking the processing speed can be omitted, or the processing speed can be checked only occasionally. Therefore, the number of non-production wafers for checking the processing speed is significantly reduced, and the productivity of the CMP apparatus is improved. Can be.

FIG. 3 shows the lower portion 7 of the CMP processing droplet shown in FIG.
FIG. 13 is a perspective view showing another configuration example. The CMP processing liquid drop lower part 7 has a configuration in which a number of processing liquid drop openings 8a and 8b are opened in a certain range from the tip of the CMP processing liquid supply pipes 2a and 2b. Also in this case, as shown in FIG. 1, the CMP of the CMP processing liquid supply pipes 2a and 2b is performed.
The processing liquid droplet lower part 7 is arranged close to the surface plate 1 so as to pass in the radial direction of the surface plate 1, and set so as to be located near the upstream with respect to the rotation direction 4 of the processing point 6.

Even if this embodiment is used, the same effects as those of the above embodiment can be obtained.
Can be simplified.

FIG. 4 is a perspective view showing a configuration of a CMP apparatus according to a second embodiment of the present invention. The shapes of the CMP processing liquid supply pipes 2a and 2b and the lower part of the CMP processing liquid drop 7 of this example are the same as those of the first embodiment shown in FIG. 1, and the arrangement of these on the surface plate 1 is also the same. .

The difference is that the processing point of the wafer 100 is 6a
When the rocking motion is performed as shown in FIGS.
There is a mechanism (not shown) for oscillating so that the distance 9 between a to 6b and the lower portion 7 of the CMP processing droplet is always constant.

This mechanism is, for example, a CMP processing droplet lower portion 7.
And a mechanism for supporting the processing point 6 on which the wafer to be processed is installed is integrally formed.
In conjunction with 0), the lower portion 7 of the CMP processing liquid drops and swings in conjunction with it.

In this embodiment, the distance 9 between the processing point 6 and the lower part 7 of the CMP processing droplet is always kept constant even when the processing point 6 of the wafer 100 swings as shown in the figure. The two types of processing fluid always reach the oscillating processing point 6 at a predetermined mixing ratio, and since the processing point is oscillating, by improving the processing uniformity and the accuracy of the processing speed, While maintaining high accuracy, productivity related to the apparatus can be improved as in the first embodiment.

It should be noted that the present invention is not limited to the above-described embodiment, and may be embodied in various other forms in terms of specific configuration, function, operation, and effect without departing from the gist of the invention. .

[0029]

As described above in detail, according to the first aspect of the present invention, since the mixing ratio of a plurality of types of processing liquids can be kept from changing on the surface plate, the CMP processing speed for the wafer is always kept constant. Therefore, the processing accuracy is improved, and the CMP processing speed confirmation operation using the non-production wafer for processing speed confirmation for each wafer or each lot can be omitted. Since the operation rate can be improved and the number of non-production wafers for processing speed confirmation can be reduced, the productivity related to the apparatus can be improved.

According to the second aspect, before the mixing ratio of the machining fluid reaches the machining point before flowing and changing on the surface plate, the CMP is performed.
The processing speed can be further stabilized, and the processing accuracy can be further improved.

According to the third aspect, since the processing uniformity of the wafer surface due to the oscillating motion of the processing point can be maintained more favorably,
The MP processing speed can be further stabilized, and the processing accuracy can be further improved.

According to the fourth aspect, it is possible to easily realize a configuration in which the lower portion of the CMP processing droplet is oscillated following the oscillating movement of the processing point.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a configuration of a CMP apparatus according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing a detailed configuration example of a lower portion of a CMP processing droplet shown in FIG. 1;

FIG. 3 is a perspective view showing another configuration example of the lower portion of the CMP processing droplet shown in FIG. 1;

FIG. 4 is a perspective view showing a configuration of a CMP apparatus according to a second embodiment of the present invention.

FIG. 5 is a perspective view showing a configuration example of a conventional CMP apparatus.

[Explanation of symbols]

 1 Surface plate 2a, 2b, 2c, 2d CMP processing liquid supply pipe 6, 6a, 6b Processing point 7, 7a, 7b Lower part of CMP processing liquid drop 8a, 8b Lower port of CMP processing liquid drop

Claims (4)

[Claims] 1. A surface of a wafer to be polished is chemically and mechanically polished by bringing the wafer to be polished into contact with a rotating platen on which a plurality of types of processing liquids are supplied and dropped from a processing liquid supply pipe. In the CMP apparatus, a lower portion of a processing liquid drop having a plurality of densely arranged dropping ports for dropping the plurality of types of processing liquid on the surface plate is formed at a tip portion of the processing liquid supply pipe. CMP apparatus. 2. The lower part of the processing droplet is arranged near the upstream of the processing point of the wafer to be polished with respect to the rotation direction of the surface plate, such that the plurality of dropping ports are opposed to and close to the surface of the surface plate. The CMP apparatus according to claim 1, wherein: 3. A mechanism for maintaining a constant distance between a lower portion of the processing droplet and the processing point when the processing point of the wafer to be polished swings.
Or the CMP apparatus according to 2. 4. The CMP apparatus according to claim 3, wherein the mechanism is configured such that a lower portion of the processing droplet is integrated with a support mechanism for swinging a processing point of the wafer.