JP2003249467A - Substrate polishing method - Google Patents

Abstract

(57) [Summary] [PROBLEMS] When two or more substrates are simultaneously polished with one polishing cloth and a fractional substrate is polished, the fractional substrate is polished by the same amount of polishing time in one batch processing. By providing the same amount of polishing when the substrate is a substrate having a step with uneven portions on the surface, a method for polishing a substrate can be provided in which even a fractional substrate is adjusted to a specified film thickness. SOLUTION: A product substrate 3 is mounted on a carrier 1 and a dummy substrate 4 is mounted on a carrier 2, and the product substrate 3 is mounted on the carrier 1.
The polishing time when the product substrate 4 is mounted on the carrier 2 is 1
Polish two batches. As the dummy substrate 4, a substrate having a film quality higher than the film quality of the product substrate and having no unevenness is selected. In place of the dummy substrate 4, a processed product of a ceramic material or a quartz material may be used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for polishing a substrate which is subjected to chemical mechanical polishing (CMP) for flattening the surface of a substrate such as a semiconductor substrate or a liquid crystal substrate.

[0002]

2. Description of the Related Art In recent years, the densification of semiconductor manufacturing processes,
Along with the miniaturization, various fine processing techniques have been researched and developed. Among them, chemical mechanical polishing (hereinafter referred to as CMP)
Is an essential technique for planarizing the interlayer insulating film.

A substrate polishing apparatus used for CMP is shown in FIG.
1, a disk-shaped platen (surface plate) 6 that rotates around a central axis, a platen shaft 7 that supports the platen 6 at the central portion, and a closed-cell polyurethane attached on the platen 6. A polishing cloth (pad) 5 made of resin or non-woven fabric, a disk-shaped carrier 1 on which a substrate 3 is mounted, a carrier shaft 8 for supporting the carrier 1 at its center, and an abrasive (slurry) containing colloidal silica as a main component. And a mechanical polishing action of pressing the surface of the substrate 3 mounted on the carrier 1 against the polishing cloth 5, and a chemical action of the polishing agent (slurry) 11 supplied during processing. The polishing operation is characterized by polishing so as to eliminate the irregularities on the substrate surface.

Further, since the substrate polishing apparatus used by the present inventor has another carrier 2, the carriers 1, 2 can simultaneously polish two substrates 3, 4 on one polishing cloth 5. You can Therefore, one batch is processed with two sheets, and the throughput can be significantly reduced.

Now, the multilayer wiring structure of the semiconductor substrate is shown in FIG.
As shown in FIG. 3, the interlayer insulating film 23 is laminated on the patterned metal wiring 22 on the silicon substrate 21, and the uneven portion 24 of the interlayer insulating film 23 is flattened and polished by the substrate polishing apparatus. .

Particularly, in the planarization process of the interlayer insulating film by CMP, the polishing time for adjusting the initial film thickness 25 to the prescribed film thickness 26 is such that the substrate having no unevenness (hereinafter referred to as a substrate without lamination of metal wiring) , R is the polishing rate obtained from the measurement of the polishing rate of the substrate (without substrate), and H is the initial film thickness 25.
i, the prescribed film thickness 26 is Ho, and the pattern density of the uneven portion in the step of the interlayer film is K

[0007]

[Equation 1]

It is derived from more. The pattern density K is a constant determined by the type and wiring layer.

Here, one batch 2 shown in FIG. 11 is shown in FIG.
The lot processing method when using a substrate polishing apparatus for single wafer processing is shown.

The polishing time T ₁ is R _{1 as} the polishing rate of the baseless substrate 3 which is polished by the carrier ₁ , and R ₂ is the polishing rate of the substrate 4 which is not processed and is polished by the carrier 2.

[0011]

[Equation 2]

Based on the above, the polishing time T _{1 for} one batch is fixed.
Then, a plurality of substrates are polished.

However, when processing a lot having an odd number of processed sheets, the final batch is the substrate 3 mounted on the carrier 1.
However, if the polishing is performed with the same polishing time as that of the previous batch in which the carriers 1 and 2 are used to polish one polishing cloth, it is impossible to adjust the film thickness to a specified value. This is because the polishing rate when polishing one substrate is different from the degree of deterioration of the surface of the polishing cloth due to clogging of the polishing cloth and polishing heat when polishing two substrates at the same time. Further, the degree of deterioration of the surface of the polishing cloth varies depending on the type because the load per unit area changes depending on the ratio of the convex portions of the substrate to be polished.

Therefore, when processing one sheet, the carrier 1
By measuring the polishing rate of the substrate without the base with only the polishing time T ₂ and inserting the polishing rate obtained from the polishing rate measurement as R ₃ in (Equation 1)

[0015]

[Equation 3]

It was necessary to carry out polishing for the obtained polishing time T ₂ obtained from the above.

[0017]

However, if the polishing time for changing the thickness of only one of the final batch to the specified film thickness is changed, the lot process must be divided.
Also, carrier 1 and carrier 2 are used to determine the polishing time.
Therefore, it is necessary to measure the polishing rate of the substrate without a base which is simultaneously polished in 1. and the polishing rate of the substrate without a base in which only the carrier 1 is polished, which affects the processing capability of the apparatus.

Therefore, in the present invention, as a method for polishing a substrate, when two or more substrates are simultaneously polished with one polishing cloth and a fractional substrate is polished, the fractional amount of the substrate is polished by 1 in the same polishing time. The purpose is to establish a method for adjusting the film thickness to a specified film even for a fractional substrate by making all substrates the same as the polishing amount in the case of using the substrate having unevenness on the surface during the batch processing.

[0019]

In order to solve the above-mentioned problems, the substrate polishing method of the present invention comprises rotating a polishing cloth attached on a surface plate at a first rotation speed so that the surface of the polishing cloth is rotated. And a polishing agent is supplied to the substrate and the substrate is rotated at a second rotation speed to press the substrate against the surface of the polishing cloth to alleviate the unevenness of the uneven portion on the surface of the substrate to obtain a prescribed film thickness. Then, a plurality of substrates are polished on the polishing cloth at the time of one batch processing, and in the case of a fractional substrate, it is also polished together with a substrate having no step on the uneven portion of another surface.

In the above method for polishing a substrate, one substrate is treated with a step having uneven portions on the surface during one batch processing,
For the other substrate, a film having a hardness higher than that of the one substrate is deposited on the substrate, and substrates having no unevenness on the surface are combined.

According to this method, the polishing amount of the one substrate can be made equal to the polishing amount when all the substrates are substrates having steps of uneven portions on the surface during one batch processing in the same polishing time.

In the above method for polishing a substrate, one substrate is sequentially formed with a step having unevenness on the surface, and the other substrate is sequentially formed with a plurality of films having a film quality higher than that of the one substrate. Substrates that are deposited and have no unevenness on the surface are combined.

By this method, the polishing amount of the one substrate can be made equal to the polishing amount when all the substrates are substrates having steps of uneven portions on the surface during one batch processing in the same polishing time.

In the above method of polishing a substrate, one of the substrates is a substrate having a step of unevenness on the surface, and the other substrate is a processed product of a ceramic material or a quartz material, and is more preferable than a film on the substrate having the step of the unevenness. Combine materials with high hardness.

By this method, the polishing amount of the one substrate can be made equal to the polishing amount when all the substrates are substrates having steps of uneven portions on the surface during one batch processing in the same polishing time.

In the above method for polishing a substrate, the substrate has a mechanism for controlling the temperature of the polishing cloth for each batch, and one substrate has a step having unevenness on the surface, and the other substrate has a film quality of the one substrate. The temperature of the polishing cloth is lowered when a substrate having the same film quality as the above and having no unevenness on the surface is combined.

By this method, the polishing amount of the one substrate can be made equal to the polishing amount when all the substrates are substrates having steps of uneven portions on the surface during one batch processing in the same polishing time.

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(First Embodiment) FIG. 1A shows a processing method for a lot in which the number of processed substrates of a substrate polishing apparatus used for CMP according to the first embodiment of the present invention is an even number. The carrier 1 and the carrier 2 can simultaneously polish the two substrates 3 and 4 on the polishing cloth 5.

FIG. 1B shows a processing method of the final batch of a lot having an odd number of processed sheets.

A lot is a substrate having a step on the uneven portion (hereinafter,
Product substrate), and the surface to be polished of the substrate is P-TEOS (Pla
sma-CVD TEOS) film, and in the present invention, the film formation state on the surface is constant, and the fluctuation of the polishing rate is small depending on the film formation state.

A method of processing lots using a substrate polishing apparatus for processing two wafers in one batch will be described.

First, using carrier 1 and carrier 2,
The polishing rate of a substrate without irregularities (hereinafter, a substrate without a base) in which an interlayer insulating film without metal wiring is laminated is measured in advance.

Next, the polishing time T, the polishing rate of the carrier 1 obtained from the polishing rate measurement results are R ₁ , the carrier 2 is
Where R _{2 is} the polishing rate, Hi is the average value of the initial film thickness 25 of the lot, Ho is the prescribed film thickness 26, and K is the pattern density of the irregularities in the interlayer film step 24.

[0035]

[Equation 4]

From the above, we will guide. The pattern density K is a constant determined by the type and wiring layer.

When processing a lot having an even number of processed sheets, the polishing time T obtained from (Equation 4) is fixed, and polishing is performed two by one batch.

When processing a lot having an odd number of processed sheets, the final batch is one product substrate. Therefore, the product substrate is mounted on the carrier 1 and the dummy substrate is mounted on the carrier 2, and the same process as in the previous batch (equation 4) is performed. 2 pieces of 1 batch are polished in the polishing time T obtained from the above.

In selecting the dummy substrate, it is sufficient to prepare a substrate having the same step as the product substrate, but it is naturally difficult from the viewpoint of cost, and according to the following embodiment, a silicon nitride (SiN) film and Substrate without base or HDP
(High Density Plasma) -A substrate with a SiO ₂ film and no underlayer is selected.

FIG. 2 shows the types of dummy substrates used for the carrier 2 in the present embodiment. In the present embodiment, the product substrate is mounted on the carrier 1 and the product substrate is mounted on the carrier 2 as Experiment 1 and polished, and in Experiment 2, the product substrate is carrier 1, the carrier 2 is silicon substrate, and the carrier 1 is product substrate in Experiment 3. , Carrier 2 is a P-TEOS (Plasma-CVD TEOS) film having the same film quality as the product, and a baseless substrate is mounted and polished.
To the product substrate, carrier 2 with a silicon nitride (SiN) film attached and polished.
Carrier 2 HDP (High Density Plasma) -SiO
_Two films are attached and polished.

FIG. 3 shows the carrier 1 of each experiment based on the polishing amount of the product substrate treated with the carrier 1 in the case of experiment 1.
The comparison result of the polishing amount of the product substrate processed in 1. is shown.

According to the results shown in FIG. 3, the state in which the product substrate is mounted on the carrier 1 and the product substrate is mounted on the carrier 2 is similar to the polished state. As a dummy substrate, a silicon nitride (SiN) film or HDP is formed on the carrier 2. (High Density Plas
It turns out that it becomes a ma) -SiO ₂ film.

FIG. 2 shows a comparison of the physical properties of each film formation.
The lower the etching rate, the higher the hardness of the film, and the higher the hardness of the silicon nitride (SiN) film or HDP.
(High Density Plasma) -By using the SiO ₂ film as a dummy substrate, the carrier 1 is the product substrate, the carrier 2 is the carrier 2.
It can also be said that the product substrate can be attached to the product to make it close to the polished state.

Here, the inventors of the present invention have noticed the following remarkable facts as a suggestion that they are correlated with the surface temperature of the polishing cloth in the method of treating a substrate having unevenness in steps. It was

FIG. 5 shows the results of non-contact measurement of the surface temperature of the polishing cloth of each experiment in which an infrared thermometer was placed on the polishing cloth as shown in FIG. 4, and the horizontal axis indicates the polishing time. The vertical axis represents the surface temperature of the polishing cloth.

From FIG. 5, the temperature curve of the polishing cloth obtained by mounting the product substrate on the carrier 1 and the silicon substrate on the carrier 2 in Experiment 2, the product substrate in Carrier 1 in Experiment 3, and the same film quality as the product in Carrier 2 were obtained. P-TEOS (Plasma-CV
The temperature curve of the polishing cloth with the D TEOS) film attached and polished is always higher than the temperature curve of the polishing cloth with the product substrate mounted on the carrier 1 and the product substrate mounted on the carrier 2 in Experiment 1. Further, the temperature curve of the polishing cloth obtained by mounting the product substrate on the carrier 1 of Experiment 4 and the silicon nitride (SiN) film on the carrier 2, and the product substrate and carrier 2 on the carrier 1 of Experiment 5
The temperature curve of the polishing cloth with the HDP (High Density Plasma) -SiO ₂ film attached to and polished is almost similar to the temperature curve of the polishing cloth with the product substrate attached to carrier 1 and the product substrate attached to carrier 2 in Experiment 1. You can see that

The reason why such a temperature difference occurs is that the substrate is
This is because the degree of clogging of the polishing cloth varies depending on the type of the film on the substrate when the wafers are processed at the same time, and a high polishing cloth temperature indicates a high polishing rate.

Therefore, in terms of the temperature curve, the carrier 1
The product substrate, and the product substrate mounted on the carrier 2 are closer to the polished state as a dummy substrate of the carrier 2 as a silicon nitride (SiN) film or HDP (High Density).
Plasma) -SiO ₂ film.

As a finding of the present invention, the surface temperature of the polishing cloth when the carrier 1 is a product substrate and the carrier 2 is a dummy substrate is the surface of the polishing cloth when the two carrier substrates 1 and 2 are processed at the same time. If the temperature is the same, the polishing rate will be the same, and the carrier 1 will have the product substrate,
It can be said that the polishing amount of the substrate when the carrier 2 is processed as a dummy substrate is the same as the polishing amount when the two carrier substrates 1 and 2 are simultaneously processed. Based on the above knowledge, the non-polished surface of the product substrate is P-TEOS (Plas
The same can be said for films other than the ma-CVD TEOS) film, for example, a typical BPSG film as an interlayer insulating film, and a dummy substrate can be easily selected by performing the same experiment as the embodiment.

By applying the present invention, even when two or more substrates are simultaneously polished in one batch,
The same effect as the above embodiment can be obtained.

(Second Embodiment) From FIGS. 5A and 5B, in Experiments 4 and 5, a sharp temperature rise was found near the end of polishing, which means that the film disappeared and the silicon substrate appeared. ing. In order to attach the product substrate to the carrier 1 and the product substrate to the carrier 2 and bring them closer to the polished state, a large amount of silicon nitride (SiN) film or HDP (High Density Plasma) -SiO ₂ film is deposited according to the polishing time. There is a need to. However, it is difficult to deposit a large amount of film with a CVD apparatus because it causes many particles.

Therefore, as the second embodiment, when the polishing time of the product substrate is 150 seconds or more, as Experiment 6, a dummy substrate used for the carrier 2 is formed on the silicon nitride (SiN) film 200 nm with HDP ( High Density
Plasma) -SiO ₂ film of 700 nm was deposited in combination with different film thicknesses.

FIG. 6 shows the carrier 1 of the experiment 6 based on the polishing amount of the product substrate treated with the carrier 1 of the experiment 1.
The comparison result of the polishing amount of the product substrate processed in 1. is shown.

From FIG. 6, carrier 1 is a product substrate, carrier 2 is a silicon nitride (SiN) film and HDP (high density).
The polishing amount of the product substrate when the substrate combined with the sity plasma) -SiO ₂ film is mounted and polished is closer to the polishing amount when the product substrate is mounted on the carrier 1 and the product substrate is mounted on the carrier 2 and polished. The values were obtained, and the temperature characteristic curve of the polishing cloth was almost the same as shown in FIG. It was found that the same effect can be obtained by combining different types of films as the dummy substrate used for the carrier 2 even if the polishing time is long.

(Third Embodiment) In the present invention, the dummy substrate used for the carrier 2 and the silicon substrate are used in the first and second embodiments, but the quartz material or the ceramic material is used in the third embodiment. The same shape (200 mm in diameter, 725 ± 25 mm in thickness) as the silicon substrate was combined in the processed product.

In this embodiment, in Experiment 1, the product substrate is mounted on the carrier 1 and the product substrate is mounted on the carrier 2 and polished. In Experiment 7, the product substrate is mounted on the carrier 1 and the processed quartz material is mounted on the carrier 2. In Experiment 8, the carrier substrate 1 is mounted with a product substrate, and the carrier 2 is mounted with a ceramic material processed product and polished.

FIG. 8 shows the comparison results of the polishing amounts of the product substrates processed by the carrier 1 in Experiments 7 and 8 with the polishing amount of the product substrate processed by the carrier 1 in Experiment 1 as a reference.

From FIG. 8, the case where the product substrate is mounted on the carrier 1, the processed product of quartz material is mounted on the carrier 2, and the carrier substrate is mounted on the carrier 1 and the processed product of ceramic material is mounted on the carrier 2 are polished. It can be seen that the polishing amount of the product substrate is similar to the polishing amount when the product substrate is mounted on the carrier 1 and the product substrate is mounted on the carrier 2.

It has been found that a similar effect can be obtained by combining a processed product of a quartz material or a ceramic material as a substitute for the dummy substrate used for the carrier 2.

However, since the processed quartz material passes through the transmitted light sensor, it is necessary to use it properly depending on the presence or absence of the transmitted light sensor. Further, if a processed product of quartz material or ceramic is used, it is possible to reuse the dummy substrate used in the first and second embodiments.

(Fourth Embodiment) FIG. 9 shows a fourth embodiment of the present invention.
It is a substrate polishing apparatus used for CMP according to the embodiment. The substrate polishing apparatus according to the present embodiment allows the carrier 1 and the carrier 2 to polish two substrates 3 and 4 at the same time on the polishing cloth 5, and the temperature of the platen 6 (platen) to which the polishing cloth is attached is controlled. The temperature of the polishing cloth is controlled for each batch by changing the temperature.

The circulation pipe 14 is a pipe for circulating and supplying pure water, and is connected to the inside of the platen 6 by a flow path.
A pump 15, a chiller 16, and a pipe thermometer 17 are provided in the circulation pipe 14, respectively. Pump is platen 6
Pure water is sent through the circulation pipe 14 toward the inside of the
The chiller 16 cools the pure water of about 23 ° C. flowing through the circulation pipe 14 to within the range of, for example, about 0 ° C. to about 20 ° C., and the pipe thermometer 17 measures the temperature of the pure water cooled by the chiller 16.

The pipe temperature control unit 18 incorporated in the control unit of the substrate polishing apparatus includes a pipe thermometer 17 and a pump 1.
5, electrically connected to the chiller 16, receives a signal based on the measurement by the in-tube thermometer 17, and pump 15, chiller 1
6. Send control signal to 6.

Next, the polishing sequence of the substrate polishing apparatus of the fourth embodiment will be described. First, the apparatus is taught the information of the final batch of the lot having an odd number of processed sheets. In the final batch, the carrier 1 is loaded with the substrate of the product, and the carrier 2 is loaded with the substrate of the same film quality as the surface to be polished of the substrate of the product and having no base. In the present embodiment, the surface to be polished of the substrate is P-TE.
It is an OS (Plasma-CVD TEOS) film, and in the present invention, the film formation state on the surface is constant, and the fluctuation of the polishing rate is small depending on the film formation state.

When polishing is next started, the pump 15 is operated to circulate and supply pure water toward the platen 6, and the pure water of 23 ° C. circulated and supplied from the chiller 16 is cooled to 20 ° C. Feedback control is performed based on the result measured by the thermometer 17, and the temperature of the pure water is kept constant, so that the temperature of the platen 6 is kept constant.

When the previous batch of the final batch is completed, the temperature of the chiller 16 is forcibly lowered, and after it is confirmed that the in-tube thermometer is stable, the final batch is processed. From the results of FIG. 8, the temperature curve of the polishing cloth obtained by mounting the product substrate on the carrier 1 and the product substrate on the carrier 2 in Experiment 1 and the temperature curve of the polishing cloth on the carrier 1 of Experiment 2 and the same film quality as the product on the carrier 2 of Experiment 2 are shown. Since the temperature difference of the surface temperature of the TEOS film which is a TEOS film and has no base is 4 degrees, the temperature of the chiller 16 is 6 to 8 degrees from 20 degrees in consideration of the thermal efficiency from the platen 6 to the polishing cloth 5. Need to lower.

FIG. 10 shows the transition of the film thickness after CMP when 25 substrates were continuously processed by using the substrate polishing apparatus of the fourth embodiment. The abscissa represents the number of the processed substrate, and the ordinate represents the film thickness after CMP and the temperature of pure water in the circulation pipe 14. The substrate of No. 25 is processed in the final batch, and the temperature of the pure water in the circulation pipe is lowered to the specified film thickness after CMP.
It can be seen that it is within 000 nm ± 200 nm.

When the polishing rate is lowered by lowering the temperature of the polishing cloth, the carrier substrate is a product substrate, and the carrier 2 is a substrate having the same film quality as the surface to be polished of the product substrate and no substrate. The polishing amount can be the same as the polishing amount when two carrier substrates 1 and 2 are processed at the same time.

By applying the present invention, even when two or more substrates are simultaneously polished in one batch,
The same effect as the above embodiment can be obtained.

[0070]

As described above, according to the present invention,
When polishing two or more substrates at the same time with one polishing cloth and polishing a fractional number of substrates, one substrate should be combined with a substrate having unevenness steps and the other substrate should be combined with a substrate having no unevenness steps. Thus, it is possible to adjust the film thickness to a specified value even with a fractional substrate with the same polishing time.

The same effect can be obtained by using a ceramic material or a quartz material as a processed product instead of a substrate having no unevenness in the uneven portion, which is also effective in reducing the number of substrates.

The same effect can be obtained by lowering the temperature of the polishing cloth.

[Brief description of drawings]

FIG. 1 is a diagram illustrating a processing operation of a final batch of a lot having an odd number of processed sheets according to the present embodiment.

FIG. 2 is a diagram showing types of dummy substrates according to the first embodiment of the present invention.

FIG. 3 is a diagram showing a comparison of polishing amounts of product substrates according to the difference in one-side used substrate in the first embodiment of the present invention.

FIG. 4 is a diagram schematically showing surface temperature measurement of a polishing cloth by an infrared thermometer according to the first embodiment of the present invention.

FIG. 5 is a diagram showing the surface temperature characteristics of the polishing pad according to the difference in the substrates used on one side in the first embodiment of the present invention.

FIG. 6 is a diagram showing a comparison of the polishing amounts of product substrates according to the difference in the substrates used on one side in the second embodiment of the present invention.

FIG. 7 is a diagram showing a surface temperature characteristic of a polishing cloth according to a difference in a substrate used on one side according to a second embodiment of the present invention.

FIG. 8 is a diagram showing a comparison of polishing amounts of product substrates according to the difference in material used on one side in the third embodiment of the present invention.

FIG. 9 is a diagram of a substrate polishing apparatus according to a fourth embodiment of the present invention.

FIG. 10 is a view showing a film thickness transition after CMP when 25 substrates are processed by using the substrate polishing apparatus according to the fourth embodiment of the present invention.

FIG. 11 is a perspective view schematically showing a polishing state of a substrate by a substrate polishing apparatus used for CMP.

FIG. 12 is a diagram showing an example of a film structure to be polished.

FIG. 13 is a diagram for explaining the conventional processing operation of the final batch of a lot with an odd number of processed sheets.

[Explanation of symbols]

1 career 2 career 3 substrates 4 substrates 5 Polishing cloth (pad) 6 Platen (surface plate) 7 Platen shaft 8 carrier axes 9 Carrier axis 10 Abrasive supply device 11 Abrasive (slurry) 12 infrared thermometer 13 Measurement points of infrared thermometer 14 Circulation piping 15 Circulation pump 16 chillers 17 In-pipe thermometer 18 Control unit 21 Silicon substrate 22 Metal wiring 23 Interlayer insulation film 24 Interlayer film step 25 Initial film thickness 26 Specified film thickness

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Katsuyuki Ikenouchi             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. F term (reference) 3C049 AA07 BA02 CA01 CB01 CB03                 3C058 AA07 BA02 CB01 CB03 DA17

Claims (5)

[Claims] 1. A polishing cloth mounted on a surface plate is rotated at a first rotation speed, an abrasive is supplied onto the surface of the polishing cloth, and the substrate is rotated at a second rotation speed to perform the polishing. A method of polishing a substrate by pressing against the surface of a cloth to reduce the unevenness of the uneven portion of the surface of the substrate to a prescribed film thickness, and polishing a plurality of substrates on the polishing cloth during one batch processing, A method of polishing a substrate, characterized in that, in the case of a fractional substrate, the substrate is polished together with another substrate having no unevenness on the uneven surface. 2. The substrate polishing method according to claim 1, wherein
A substrate having one surface having a step of unevenness on the surface during one batch processing, the other substrate having a film having a hardness higher than that of the one substrate deposited on the substrate and having no unevenness of the surface unevenness The substrate is characterized in that the polishing amount of one of the substrates is the same as the polishing amount when all the substrates are substrates having steps of uneven portions on the surface during one batch processing in the same polishing time. Polishing method. 3. The substrate polishing method according to claim 1, wherein
One substrate is a substrate having a step of unevenness on the surface, the other substrate is sequentially deposited on the substrate a plurality of different types of film having a film quality higher than the film quality of the one substrate, and By combining the substrates having no step, the polishing amount of the one substrate can be made equal to the polishing amount when all the substrates are the substrates having the step of the uneven portion of the surface in one batch processing in the same polishing time. A characteristic substrate polishing method. 4. The substrate polishing method according to claim 1, wherein
By combining one substrate with a step having unevenness on the surface and the other substrate with a material having a hardness higher than that of a film on the substrate having the unevenness of the unevenness, which is a processed product of a ceramic material or a quartz material, A substrate polishing method, wherein the polishing amount of one substrate is set to be the same as the polishing amount when all substrates are substrates having steps of uneven portions on the surface during one batch processing with the same polishing time. 5. The substrate polishing method according to claim 1, wherein
It has a mechanism to control the temperature of the polishing cloth for each batch.
The temperature of the polishing cloth is lowered when one substrate is combined with a substrate having unevenness on the surface, and the other substrate is combined with a film having the same film quality as that of the one substrate and having no unevenness on the surface unevenness. Accordingly, the polishing amount of the one substrate is made the same as the polishing amount when all the substrates are substrates having steps of uneven portions on the surface during one batch processing in the same polishing time. .