JP3556300B2 - Polishing equipment - Google Patents

Description

[0001]
[Industrial applications]
The present invention relates to a polishing apparatus, and more particularly to a polishing apparatus which can be installed in a clean room.
[0002]
[Prior art]
The polishing apparatus is an apparatus for processing a wafer by pressing the wafer against a polishing cloth attached on a surface plate, for example, to obtain a high mirror surface on the wafer surface.
[0003]
In particular, in recent years, single-sided polishing technology conventionally used in a semiconductor manufacturing process has been applied to the field of semiconductor device processing, and this applied technology is called chemical mechanical polishing (CMP) technology. Is called a CMP apparatus.
[0004]
When a wafer is polished by using such a polishing apparatus, a large amount of particles are generated, so that the polishing apparatus cannot be installed in a normal clean room.
[0005]
Therefore, the conventional polishing apparatus has been installed in a separate room having a lower degree of cleanness than a normal clean room. Then, the wafer is carried into the separate room from the clean room, the wafer is processed and washed by using a polishing apparatus, and then the wafer is returned to the clean room again to proceed to the next step.
[0006]
[Problems to be solved by the invention]
However, when the polishing apparatus is installed in a separate room as described above, the entire flow of the semiconductor manufacturing process stays at the polishing apparatus, which is a major obstacle in automating the entire manufacturing process. In addition, the cost for providing the separate room is not only extra, but it is necessary to clean the wafer every time the wafer is transferred from the low clean room to the high clean room.
[0007]
Therefore, an object of the present invention is to provide a polishing apparatus that can be installed in a clean room.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, a polishing apparatus according to the present invention comprises: a working chamber divided into a plurality of compartments by partitioning means; a means for performing polishing installed on the inside of the compartments on a workpiece; Communication means for making adjacent compartments divided by the means communicate with each other.
[0009]
Further, it is preferable to provide means for individually controlling the internal pressures of the plurality of compartments.
[0010]
Further, a means for generating an air current may be provided inside the compartment.
[0011]
Further, the airflow may be a laminar flow.
[0012]
Further, the communication means may be a gate valve.
[0013]
Further, the communication means may be an air curtain.
[0014]
Further, the means for applying the polishing to the workpiece may be a means for applying the chemical mechanical polishing to the workpiece.
[0015]
[Action]
The work room is divided into a plurality of compartments by partitioning means, and means for polishing the workpiece are installed inside the compartments.Therefore, compartments with low cleanliness, especially means for polishing the workpiece, are installed. The movement of particles from the divided compartment to the compartment having a high degree of cleanliness is restricted. Further, when the wafer is moved between the compartments, the wafer is moved in a communication state between the compartments via the communicating means provided on the partition member.
[0016]
Further, since the internal pressure of each of the plurality of compartments is individually controlled in accordance with the degree of cleanness in each of the compartments, the internal pressure can be increased as the degree of cleanness of the compartments increases. With this configuration, even when the compartments are in communication with each other, the flow of air between the compartments is generated from the compartment having a high degree of cleanness to the compartment having a low level of cleanness, so that the air flows between the compartments having a low degree of cleanness. A large amount of existing particles do not flow into a highly clean compartment.
[0017]
Furthermore, by generating an airflow inside each of the compartments, the diffusion of particles can be suppressed.
[0018]
Further, if the air flow is made laminar, the particles can be prevented from rising.
[0019]
Further, if the communication means is constituted by a gate valve, the communication between the compartments or the closed state can be reliably controlled.
[0020]
In addition, if the communication means is constituted by an air curtain, an operating section is not required and the structure is simple.
[0021]
Further, if the means for applying the polishing to the workpiece is constituted by means for applying the chemical mechanical polishing to the workpiece, it is possible to perform the chemical mechanical polishing while preventing the diffusion of particles generated at the time of polishing. .
[0022]
【Example】
Hereinafter, an embodiment of a polishing apparatus, particularly, a CMP apparatus according to the present invention will be described with reference to FIGS.
1 and 2, reference numeral 1 denotes a clean bench of a CMP apparatus disposed inside a clean room A. The clean bench 1 has an outer wall 2, and a wafer transfer door 3 is provided on the outer wall 2. The work chamber 4 of the clean bench 1 has an airtight structure by the outer wall 2 and the wafer transfer door 3. As shown in FIG. 2, a clean unit 5 is provided above the clean bench 1, and clean air flows downward from the clean unit 5. The airflow from the clean unit 5 flows into the exhaust area 7 through the laminar flow control plate 6 provided at the lower part of the clean bench 1. The airflow flowing into the exhaust area 7 is discharged to the outside of the clean room A via an exhaust duct (not shown). Instead of using the exhaust duct, the air in the exhaust area 7 may be purified by a filter and then circulated to the work room 4 of the clean bench 1 for reuse. In this case, a HEPA or ULPA filter is used as a filter. If these filters are used in combination with a chemical filter, sodium (Na) contamination can be prevented.
[0023]
The inside of the work room 4 of the clean bench 1 is divided into a first compartment 9, a second compartment 10, a third compartment 11, and a fourth compartment 12 by a partition plate 8, and among these compartments, The first compartment 9 is formed corresponding to the position where the above-described wafer transfer door 3 is provided. The internal pressures of these compartments are individually controlled in accordance with the degree of cleanness by an air volume adjusting device (not shown). Further, the pressure in the exhaust area 7 and the air volume in the clean unit 5 are adjusted so that the internal pressure of these compartments becomes negative with respect to the pressure in the clean room A.
[0024]
Further, a first gate valve 13 is provided on a partition plate 8 for separating the first compartment 9 and the second compartment 10, and hereinafter, the partition plate 8 for separating the second and third compartments 10 and 11 is provided. Is a second gate valve 14, a third gate valve 15 is provided on a partition plate 8 that partitions the second and fourth compartments 10 and 12, and a third gate valve 15 is provided on a partition plate 8 that partitions the first and fourth compartments 9 and 12. Four gate valves 16 are provided, respectively. Instead of these gate valves, openings may be provided at the same position as the position of the gate valve, and these openings may be closed by an air curtain. In this case, the air curtain is preferably a thin airflow that flows at a high speed along the partition plate. If an air curtain is used in this way, an operating unit such as a gate valve is not required, and the structure is simplified.
[0025]
Further, the first compartment 9 is provided with a first wafer carrier 17 and a second wafer carrier 18, and a first robot 19 for transporting a wafer inside the first wafer carrier 17 to the second compartment 10. The first robot 19 is also used when loading a wafer inside the fourth compartment 12 into the first compartment 9. The second compartment 10 is provided with a wafer receiving table 20 and a second robot 21 for transferring a wafer on the wafer receiving table 20 to the third compartment 11. The second robot 21 is also used when loading a wafer inside the third compartment 11 into the fourth compartment 12 via the second compartment 10. Further, the third compartment 11 is provided with a loader 22, a polishing device 23 for polishing a wafer received from the loader 22, and a dressing device 24. The fourth compartment 12 is provided with a cleaning / drying device 25 for cleaning and drying the wafer processed by the polishing device 23. The cleaning / drying device 25 includes a back surface cleaning device 26 and a front surface cleaning device 26. It comprises a device 27 and a rinsing / drying device 28.
[0026]
The pressure inside each compartment is controlled according to the degree of cleanness of each compartment when the CMP apparatus is operating. That is, the first and fourth compartments 9 and 12 have the highest cleanliness of each compartment during operation of the CMP apparatus, and then the second compartment 10 and the third compartment 11 are in order. In particular, since a large amount of particles are generated during the polishing of the wafer inside the third compartment 11, the cleanness is very low. The internal pressure of each compartment is controlled to be higher in compartments having a higher degree of cleanness.
[0027]
Next, the operation of the present embodiment will be described.
A plurality of wafers before processing are stored in the first wafer carrier 17 carried into the first compartment 9 of the clean bench 1 via the wafer transfer door 3. One of these wafers is taken out by the first robot 19, the first gate valve 13 is opened, the wafer is carried into the second compartment 10, and is placed on the wafer receiving table 20. The gate valve 13 is closed.
[0028]
When the wafer is moved from the first compartment 9 to the second compartment 10 in this manner, the first gate valve 13 is opened, but the pressure inside the second compartment 10 is reduced to the first compartment. Since the pressure is lower than the pressure inside 9, the air flow through the first gate valve 13 flows from the first compartment 9 to the second compartment 10. Therefore, the air inside the second compartment 10 having a low cleanness does not flow into the first compartment 9 having a high cleanness.
[0029]
Further, the pressure in the exhaust area 7 and the air volume in the clean unit 5 are adjusted so that the internal pressure of the first compartment 9 becomes negative with respect to the pressure in the clean room A. When the wafer transfer door 3 is opened, the dirty air inside the working chamber 4 does not flow into the clean room A.
[0030]
Next, the second robot 21 receives the wafer on the wafer receiving table 20, opens the second gate valve 14, loads the wafer into the third compartment 11, passes the wafer to the loader 22, and then performs the second The gate valve 14 is closed. Even when the second gate valve 14 is opened, the pressure inside the third compartment 11 is lower than the pressure inside the second compartment 10, so that the air flow through the second gate valve 14 From the second compartment 10 to the third compartment 11. For this reason, the contaminated air inside the third compartment 11 having a very low cleanness does not flow into the second compartment 10.
[0031]
The wafer is sent from the loader 22 to the polishing device 23 where the wafer is polished. In the polishing, a large amount of particles are generated, and the cleanliness of the third compartment 11 decreases. However, since the descending flow from the clean unit 5 guides particles to the exhaust area 7, the cleanliness of the third compartment 11 is restored to some extent. Since the downward flow from the clean unit 5 is provided not only to the third compartment 11 but also to the first, second, and fourth compartments 9, 10, and 12, the cleanness of each compartment is temporarily reduced. Even if it is lowered, the degree of cleanness is restored to some extent by this downward flow.
[0032]
After the polishing of the wafer is completed, the second gate valve 14 is opened, and the processed wafer is received by the second robot 21. Then, after closing the second gate valve 14, the third gate valve 15 is opened to carry the wafer into the back surface cleaning device 26 in the fourth compartment 12, and then the third gate valve 15 is closed. Even when the third gate valve 15 is opened, the pressure inside the fourth compartment 12 is higher than the pressure inside the second compartment 10, so that the air flow through the third gate valve 15 The four compartments 12 are directed to the second compartment 10. Therefore, the air inside the second compartment 10 having a low cleanness does not flow into the fourth compartment 12.
[0033]
Then, the wafer is washed and dried by sequentially transferring the wafer from the back surface cleaning device 26 to the front surface cleaning device 27 and further to the rinsing / drying device 28 by a wafer transfer device (not shown) provided in the cleaning / drying device 25. Thereafter, the fourth gate valve 16 is opened, and the cleaned and dried wafer is carried into the first compartment 9 by the first robot 19, the fourth gate valve 16 is closed, and the wafer is stored in the second wafer carrier 18. I do.
[0034]
By repeating the above steps, all the wafers inside the first wafer carrier 17 are processed and housed inside the second wafer carrier 18. Finally, the wafer transfer door 3 is opened, and the second wafer carrier 18 is taken out together with the processed wafer.
[0035]
【The invention's effect】
As described above, according to the present invention, the working chamber is divided into a plurality of compartments by the partitioning means, and the means for performing polishing on the workpiece is installed inside the compartments. In particular, the movement of particles from a compartment provided with a means for applying polishing to a workpiece to a compartment having a high degree of cleanliness is restricted. For this reason, even when the polishing apparatus is installed in a clean room, it is possible to prevent particles generated during the operation of the polishing apparatus from diffusing into the clean room and contaminating the clean room, and to clean particles in the clean bench. Contamination can be prevented.
[0036]
In addition, since the internal pressure of each of the plurality of compartments is individually controlled in accordance with the degree of cleanness in each of the compartments, and the compartment pressure having a higher degree of cleanness can be increased, the internal pressure can be increased. Even when the rooms are in communication with each other, the flow of air between the compartments occurs from a compartment having a high degree of cleanness to a compartment having a low degree of cleanness. As a result, a large amount of particles present in the low-clean compartment do not flow into the high-clean compartment, and particles generated during the operation of the polishing apparatus are diffused into the clean room to be cleaned. Can be reliably prevented, and a clean wafer in a clean bench can be reliably prevented from being contaminated by particles.
[0037]
Furthermore, since an air current can be generated inside each of the compartments, the air current can suppress the diffusion of particles. For this reason, it is possible to more reliably prevent particles generated during the operation of the polishing apparatus from diffusing into the clean room and contaminating the clean room, and to more reliably prevent clean wafers in the clean bench from being contaminated by the particles. Can be prevented.
[0038]
In addition, if the air flow is made laminar, particles can be prevented from rising, so that contamination of a clean room and contamination of a clean wafer can be more reliably prevented.
[0039]
Further, if the communication means is constituted by a gate valve, the communication between the compartments or the closed state can be reliably controlled.
[0040]
In addition, if the communication means is constituted by an air curtain, the operation section is not required, and the structure is simplified.
[0041]
Further, if the means for performing polishing on the workpiece is constituted by means for applying chemical mechanical polishing to the workpiece, it is possible to perform chemical mechanical polishing while preventing diffusion of particles generated during polishing.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a main part of an embodiment of a polishing apparatus according to the present invention.
FIG. 2 is a longitudinal sectional view showing a part of the clean bench of the embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Clean bench 2 Outer wall 4 Work room 5 Clean unit 6 Laminar flow adjusting plate 8 Partition plate 9 1st compartment 10 2nd compartment 11 3rd compartment 12 4th compartment 13 First gate valve 14 Second gate valve 15 Third gate valve 16 Fourth gate valve 23 Polishing device

Claims (7)

A work room divided into a plurality of compartments by partition means,
Means for applying polishing to the workpiece, which is installed inside the compartment,
Communication means for making adjacent compartments separated by the partition means in a communication state,
Means for generating an airflow from the ceiling of each of the compartments toward the floor . The plurality of compartments include first to fourth compartments,
A workpiece to be conveyed into the polishing apparatus is stored in the first compartment,
The second compartment is communicated with the first compartment and the third compartment by the communicating means, and the internal pressure is set lower than that of the first compartment, and the second compartment is connected to the first compartment. The workpiece in the compartment is configured to be transported,
The third compartment has an internal pressure set lower than that of the second compartment, and a means for applying the polishing to the workpiece is disposed, and the third compartment has the processing pressure in the second compartment. Transporting the workpiece to the second compartment after loading and polishing the workpiece;
The fourth compartment is communicated with the second compartment and the first compartment by the communicating means, and the internal pressure is set higher than that of the second compartment, so that the workpiece is Means for cleaning and drying are arranged, and the workpiece subjected to polishing is carried in from the second compartment, washed and dried, and then unloaded to the first compartment. The polishing apparatus according to claim 1, wherein the polishing apparatus is configured as follows. Polishing device according to claim 1 or 2, characterized in that it comprises means for individually controlling the internal pressure of the plurality of compartments. Polishing device according to any one of claims 1 to 3, wherein the air flow is laminar. The polishing apparatus according to any one of claims 1 to 4, wherein the communicating means comprises a gate valve. Polishing device according to any one of claims 1 to 4, characterized in that said communicating means is formed of an air curtain. The polishing apparatus according to any one of claims 1 to 6, wherein the means for performing the polishing on the workpiece is a means for performing the chemical mechanical polishing on the workpiece.

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