JP2000260671A - Dust adsorbing wafer and method of cleaning inside of semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a dust adsorbing wafer and a method of cleaning the inside of the wafer capable of suppressing the re-deposition of dust produced due to the disassembling of an apparatus and other human factors and removing dust adjacent to the wafer. SOLUTION: Dummy wafers 11a and 11b which are positively and negatively charged by a corona charge are formed. Next, the positively charged wafer 11a is forwarded idly within a semiconductor manufacturing apparatus, whereby negatively charged dust whose polarity is opposite to that of the wafer 11a is adsorbed to the wafer 11a by electrostatic force. Next, the same operation is performed for the wafer 11b. During these operations, stray dust present not only in regions which are in contact with the wafers 11a and 11b, but also within regions upon which the influence of electrostatic forces within the apparatus is exerted can be removed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to cleaning of a semiconductor manufacturing apparatus, and more particularly, to a dust suction wafer used for removing dust in a portion in contact with a wafer and in the vicinity thereof, and a method of cleaning a semiconductor device.

[0002]

2. Description of the Related Art Conventionally, when a wafer is transferred in a semiconductor manufacturing apparatus, various problems have arisen due to dust in the semiconductor manufacturing apparatus adhering to the wafer. If the dust adheres to the main surface of the wafer, it may cause disconnection of wiring. Further, when dust adheres to the back surface of the wafer, problems such as occurrence of misalignment in lithography, unevenness of the electrostatic chuck, and unevenness of wafer cooling occur. Therefore, in order to remove the dust, the apparatus has been regularly cleaned.

However, when cleaning the inside of a chamber having a vacuum chamber, it is necessary to temporarily release the vacuum state. Therefore, it takes approximately 1 to 1.5 days to start up the chamber again and form a stable vacuum state.

In order to reduce the number of times of maintenance, there is a method of performing plasma discharge for cleaning to remove dust on the inner wall of the chamber.

However, in this case, it is impossible to simultaneously remove dust from the transfer system such as the transfer arm and the transfer belt, and it has been necessary to remove the side wall of the apparatus and wipe and clean the parts manually.

[0006] Further, even in a device other than a vacuum system device, maintenance of dust in a narrow gap in which manual operation cannot be performed requires removing the side wall of the device. For this reason, when the side wall of the apparatus was opened and closed, dust was involved.

[0007] Further, dust generation in a clean room is mainly caused by humans, and there is a problem of reverse contamination that dust is re-adhered to a wafer by wiping the inside of the apparatus.

On the other hand, there has been proposed a method in which an adhesive thin film is formed on a dummy wafer, and the wafer is transferred to remove dust in a portion in contact with the wafer.

As shown in FIG. 10A, an adhesive sheet 92 is fixed to the front and back surfaces of a dummy wafer 91 having a wafer shape. That is, as shown in FIG. 10B, a wafer 94 in which the front and back surfaces of the dummy wafer 91 are covered with the adhesive sheet 92 is formed. The adhesive sheet 92 is provided with a non-adhesive portion 93 for peeling.

Next, the wafer 94 is transferred to the semiconductor manufacturing apparatus. Thus, the dust in the semiconductor manufacturing apparatus is adsorbed by the adhesive force of the adhesive sheet 92.

However, in this case, there is a problem that only dust in the contact portion with the wafer is removed, and dust in the vicinity thereof cannot be removed.

[0012]

As described above, the above-described conventional dust removing method prevents the occurrence of reverse adhesion of dust,
In addition, dusts other than those in direct contact with the wafer cannot be completely removed.

Therefore, dust adhering to the wafer passing through the semiconductor manufacturing apparatus cannot be sufficiently suppressed, and a sufficient improvement in yield cannot be expected. In addition, since dust at a portion other than the portion directly in contact with the wafer cannot be removed, it is necessary to disassemble and clean (clean) the device, and as described above, reverse adhesion of dust is inevitable.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to suppress the reverse adhesion of dust generated due to the disassembly of the apparatus and human factors, and to remove the dust near the wafer. Another object of the present invention is to provide a method for cleaning the inside of a semiconductor device and a wafer for dust suction, and to improve the yield of products by increasing the operation rate by reducing the frequency of cleaning (cleaning) of the device.

[0015]

The present invention uses the following means to achieve the above object.

The dust suction wafer of the present invention is a dust suction wafer for cleaning the inside of a semiconductor manufacturing apparatus, and a dummy wafer simulating a wafer is charged.

The dummy wafer has an adhesive layer formed on at least a part of a front surface, a back surface, and a side surface.

The dust suction wafer of the present invention simulates a wafer, and includes a charged dummy wafer, and insulating films formed on the front, back, and side surfaces of the dummy wafer.

The insulating film has an adhesive layer formed on at least a part of a front surface, a back surface, and a side surface.

The dummy wafer is made of any one of insulating materials such as silicon, quartz, safar, synthetic resin, and ceramic.

The absolute value of the potential of the charged dummy wafer is at least 10V.

The dust suction wafer of the present invention has a dummy wafer simulating a wafer, and a thin film formed on at least a part of the front, back, and side surfaces of the dummy wafer and charged with electric charge.

The dummy wafer is made of any one of silicon, quartz, safal, metal, and synthetic resin.

The thin film is a polymer thin film.

The thin film has an adhesive layer formed on at least a part of a front surface, a back surface, and a side surface.

The absolute value of the potential of the charged thin film is at least 10V.

The dust suction wafer of the present invention has a dummy wafer simulating a wafer, and a sheet formed on at least a part of a front surface, a back surface, and a side surface of the dummy wafer and charged with electric charge. It has the nature.

The absolute value of the potential of the charged sheet is at least 10V.

According to the method of cleaning the inside of a semiconductor device of the present invention, a dummy wafer imitating a wafer is charged in a first step, and the wafer is transported empty into the semiconductor device. And a second step of sequentially transporting.

The first step is a step of forming a charged thin film on at least a part of the front, back, and side surfaces of the dummy wafer simulating the wafer.

The first step is a step of forming a charged thin film having an absolute value of a potential of at least 10 V on at least a part of a front surface, a back surface, and a side surface of the dummy wafer simulating the wafer.

In the first step, a sheet having a charge on at least a part of a front surface, a back surface, and a side surface of a dummy wafer simulating the wafer is arranged by the adhesiveness of the sheet.

In the first step, a sheet charged with an electric charge having an absolute value of at least 10 V on at least a part of a front surface, a back surface, and a side surface of the dummy wafer simulating the wafer is disposed due to the stickiness of the sheet. I do.

[0034]

Embodiments of the present invention will be described below with reference to the drawings.

[First Embodiment] First, a dummy wafer 11 having a wafer shape as shown in FIG. 1A is used. Here, the dummy wafer 11 has an insulating material such as silicon, quartz, safal, synthetic resin, ceramic or the like as a base material. The dummy wafer 11 is subjected to, for example, corona charging to form positive or negatively charged dummy wafers 11a and 11b as shown in FIGS. 1B and 1C. Here, in order to adsorb the dust, the charged dummy wafers 11a and 11b need to have a potential of, for example, 10 V or more as an absolute value. Note that this potential changes depending on the diameter of the dust, the distance from the dummy wafer to the dust, and the like. In addition, the potential is set to such an extent that the wafer is not broken and the apparatus is not adversely affected.

Next, the positively charged dummy wafer 11a is transported in the semiconductor manufacturing apparatus,
Negatively charged dust having a potential opposite to that of 1a is attracted to the dummy wafer 11a by electrostatic force. Next, the negatively charged dummy wafer 11b is transported, and the positively charged dust is attracted by the electrostatic force of the dummy wafer 11b. At this time, the order of use of the dummy wafers 11a and 11b may be any order.

Thereafter, dust adhering to the dummy wafers 11a and 11b is removed by, for example, static elimination or wet cleaning.

According to the first embodiment, dust in the apparatus can be removed without disassembling the apparatus. For this reason, the reverse adhesion of dust generated by human factors can be suppressed. Further, dust floating in the apparatus can be removed not only in the area where the electrostatic force affects the wafers 11a and 11b but also in a range where the electrostatic force affects.

[Second Embodiment] Next, a second embodiment of the present invention will be described. In the second embodiment, only parts different from the first embodiment will be described.

FIG. 2A shows a dummy wafer 21 having a wafer shape applied to the second embodiment. The dummy wafer 21 has an insulating material such as silicon, quartz, safal, synthetic resin, or ceramic as a base material.

Next, as shown in FIG. 2B, a thin film 22 made of, for example, a silicon oxide film is formed on the entire surface of the dummy wafer 21. The thin film 22 is formed by depositing a material of a silicon oxide film, or applying or invading a liquid material, and then evaporating to dryness.

Next, as shown in FIG. 2C, for example, corona charging is performed on the dummy wafer 21 to form, for example, a positively charged dummy wafer 21a. Thus, as shown in FIG. 2D, a wafer 23 in which the entire surface of the charged dummy wafer 21a is covered with the thin film 22 is formed.

Next, as in the first embodiment, the wafer 23 is transported in the semiconductor manufacturing apparatus, and dust charged to the opposite potential is attracted by the electrostatic force of the dummy wafer 21a.

Thereafter, dust adhering to the wafer 23 is removed by, for example, corona charging again. here,
For removing dust, wet cleaning using a liquid such as ammonium fluoride (NH ₄ F) may be performed.

According to the second embodiment, dust in the apparatus can be removed without disassembling the apparatus. For this reason, the reverse adhesion of dust generated by human factors can be suppressed. In addition, dust floating in the apparatus can be removed not only in a portion where the electrostatic force is brought into contact with the wafer 23 but also in a range where the effect of the electrostatic force is exerted. Further, the charged dummy wafer 21a is covered with a thin film 22 which is an insulating film. Therefore, when the wafer 23 is transferred in the apparatus, even when the wafer 23 comes into contact with another metal,
This makes it possible to prevent charges from escaping.

Third Embodiment Next, a third embodiment of the present invention will be described. In the third embodiment, only parts different from the first embodiment will be described.

FIG. 3A shows a dummy wafer 31 having a wafer shape applied to the third embodiment. The dummy wafer 31 has a base material of, for example, silicon, quartz, safal, synthetic resin, metal, or the like.

Next, as shown in FIG. 3B, a chargeable thin film 32 is formed on the entire surface of the dummy wafer 31.
The chargeable thin film 32 is formed by depositing a thin film material, coating or infiltrating a liquid material, and then evaporating to dryness.
Here, the charging thin film 32 is a polymer thin film.

Next, as shown in FIG. 3C, for example, a corona charge is applied to the chargeable thin film 32 to form, for example, a positively charged thin film 32a. Thus, FIG.
As shown in (d), a wafer 33 is formed in which the entire surface of the dummy wafer 31 is covered with the charged thin film 32a. Here, the thin film 32 may be charged before being fixed to the dummy wafer 31. The area to be charged is not limited to the entire surface. For example, dummy wafer 3
It suffices that at least one or a part of the thin film among the front surface, the back surface, and the side surface is charged.

Next, as in the first embodiment, the wafer 33 is carried in the semiconductor manufacturing apparatus, and dust charged to the opposite potential is attracted to the wafer 33 by electrostatic force.

Thereafter, the charged thin film 3 to which dust has adhered is cleaned by wet cleaning using a solution such as hydrogen peroxide.
2a is removed.

According to the third embodiment, dust in the apparatus can be removed without disassembling the apparatus. For this reason, the reverse adhesion of dust generated by human factors can be suppressed. Further, dust floating in the apparatus can be removed not only in a portion where the electrostatic force is brought into contact with the wafer 33 but also in a range where the electrostatic force affects.

[Fourth Embodiment] Next, a fourth embodiment of the present invention will be described. In the fourth embodiment, a charging sheet and an adhesive sheet are used to more surely adsorb dust.

As shown in FIG. 4, for example, a polymer charging sheet 42 is formed on the front and back surfaces of the dummy wafer 41, and an adhesive sheet 43 is formed on the entire surface of the charging sheet 42.
Is formed. That is, as shown in FIG. 5, the front and back surfaces of the dummy wafer 41 are
3 is covered. The adhesive sheet 43 is provided with a non-adhesive portion 44 for peeling. Here, regardless of the shape of the adhesive sheet 43, it is only necessary that an adhesive area is provided in a part of the charging sheet 42.

Next, as in the first embodiment, the wafer 41 having the charging sheet 42 and the adhesive sheet 43 is transported in the semiconductor manufacturing apparatus. As a result, the dust charged to the opposite potential by the electrostatic force of the charging sheet 42 is adsorbed to the adhesive sheet, and the adhesive force of the adhesive sheet 43 makes the adsorption more reliable.

Next, the adhesive sheet 43 to which the dust has adhered is peeled by pulling the peeling non-adhesive portion 44 by hand. Thereafter, a new adhesive sheet is attached. Here, the attachment and detachment of the adhesive sheet 43 may be performed not only by hand but also by, for example, a jig or a device.

According to the fourth embodiment, dust in the apparatus can be removed without disassembling the apparatus. For this reason, the reverse adhesion of dust generated by human factors can be suppressed. In addition, dust floating in the apparatus can be removed as long as the electrostatic force affects not only the portion in contact with the wafer 41 and the like due to the electrostatic force. Further, by using the pressure-sensitive adhesive sheet 43, dust in a portion in contact with the wafer 41 or the like can be more reliably adsorbed. Also,
In the dust removal, the charged wafer 41 can be reused without affecting the wafer 41 only by replacing the adhesive sheet 43.

Further, for example, as shown in FIGS. 6 to 8, an adhesive sheet 51 may be fixed to the front and back surfaces of each of the wafers 11a, 23, and 33 shown in the first to third embodiments. . The adhesive sheet 51 has a non-adhesive portion 52 for peeling. With such a configuration, the same effect as in the fourth embodiment can be obtained.

The fourth embodiment is not limited to these. For example, as shown in FIG. 9, a sheet 82 in which a charged sheet and an adhesive sheet are integrated may be formed on the front and back surfaces of a dummy wafer 81. That is, the sheet 82 is charged, and has a sticky surface.

As described above, according to the first to fourth embodiments, by using a charged wafer, it is possible to remove dust in a portion where the wafer comes into contact and in a range where electrostatic force can reach without disassembling the apparatus. It can be removed. Therefore, dust generated due to human factors due to disassembly of the apparatus is reduced, and problems such as misalignment of lithography due to dust and disconnection can be avoided.

According to the first to fourth embodiments,
Although corona charging is performed as a method for charging a wafer or the like, the method is not limited to this. For example, plasma discharge or the like may be used.

In addition, the present invention can be variously modified and implemented without departing from the gist thereof.

[0063]

As described above, the dust suction wafer described above is transported empty into the semiconductor manufacturing apparatus, whereby the dust in the apparatus can be reduced and the product yield can be improved. Further, it is possible to save the trouble of disassembling and cleaning (cleaning) the manufacturing apparatus, and it is possible to greatly improve the operation rate particularly in an apparatus having a vacuum chamber.

[Brief description of the drawings]

FIG. 1 is a perspective view of a wafer according to a first embodiment of the present invention.

FIG. 2 is a perspective view of a wafer according to a second embodiment of the present invention.

FIG. 3 is a perspective view of a wafer according to a third embodiment of the present invention.

FIG. 4 is a perspective view of a wafer according to a fourth embodiment of the present invention.

FIG. 5 is a sectional view of a wafer according to a fourth embodiment of the present invention.

FIG. 6 is a perspective view showing a case where the fourth embodiment is applied to the first embodiment.

FIG. 7 is a perspective view showing a case where the fourth embodiment is applied to the second embodiment.

FIG. 8 is a perspective view showing a case where the fourth embodiment is applied to the third embodiment.

FIG. 9 is a perspective view showing a modification of the fourth embodiment.

FIG. 10 is a perspective view of a conventional wafer.

[Explanation of symbols]

 11, 21, 31, 41, 81: dummy wafer, 11a, 21a: positively charged dummy wafer, 11b: negatively charged dummy wafer, 22: thin film, 23, 33: wafer, 32: charged thin film, 32a ... Positively-charged thin film, 42. Charged sheet, 43, 51. Adhesive sheet, 44, 52. Non-adhesive part for peeling, 82. Sheet in which a charged sheet and an adhesive sheet are integrated.

Claims (18)

[Claims] 1. A dust suction wafer for cleaning the inside of a semiconductor manufacturing apparatus, wherein a dummy wafer simulating a wafer is charged with electric charge. 2. A dust suction wafer, simulating a wafer, comprising: a charged dummy wafer; and insulating films formed on the front, back, and side surfaces of the dummy wafer. 3. A dust suction wafer comprising: a dummy wafer simulating a wafer; and a thin film formed on at least a part of a front surface, a back surface, and a side surface of the dummy wafer and charged with electric charge. 4. A dummy wafer simulating a wafer, and a sheet formed on at least a part of a front surface, a back surface, and a side surface of the dummy wafer and charged with electric charge, wherein the sheet has adhesiveness. Characteristic dust suction wafer. 5. The dummy wafer is made of silicon, quartz,
The dust suction wafer according to claim 1, wherein the wafer is made of any one of insulating materials such as safar, synthetic resin, and ceramic. 6. The dummy wafer is made of silicon, quartz,
The dust suction wafer according to claim 3, wherein the wafer is made of any one of safar, metal, and synthetic resin. 7. The dust suction wafer according to claim 3, wherein the thin film is a polymer thin film. 8. The dust suction wafer according to claim 1, further comprising an adhesive layer formed on at least a part of a front surface, a back surface, and a side surface of the dummy wafer. 9. The dust suction wafer according to claim 2, further comprising an adhesive layer formed on at least a part of a front surface, a back surface, and a side surface of the insulating film. 10. The dust suction wafer according to claim 3, further comprising an adhesive layer formed on at least a part of a front surface, a back surface, and a side surface of the thin film. 11. The dust suction wafer according to claim 1, wherein an absolute value of a potential of the charged dummy wafer is at least 10V. 12. The dust suction wafer according to claim 3, wherein an absolute value of a potential of the charged thin film is at least 10V. 13. The dust suction wafer according to claim 4, wherein the absolute value of the potential of the charged sheet is at least 10V. 14. A first step of charging a dummy wafer simulating a wafer with a charge, and a second step of successively transferring the oppositely charged wafer after the wafer is vacantly transferred into a semiconductor device. A method for cleaning a semiconductor device, comprising: 15. The method according to claim 14, wherein the first step is a step of forming a charged thin film on at least a part of a front surface, a back surface, and a side surface of the dummy wafer simulating the wafer. A method for cleaning a semiconductor device. 16. The first step is a step of forming a charged thin film having an absolute value of at least 10 V on at least a part of a front surface, a back surface, and a side surface of a dummy wafer simulating the wafer. The method for cleaning the inside of a semiconductor device according to claim 14, wherein: 17. The method according to claim 1, wherein the first step includes arranging a sheet having a charge on at least a part of a front surface, a back surface, and a side surface of the dummy wafer simulating the wafer by the adhesiveness of the sheet. Item 15. A method for cleaning a semiconductor device according to Item 14. 18. The method according to claim 1, wherein the first step comprises: charging a sheet having an electric charge having an absolute value of at least 10 V on at least a part of a front surface, a back surface, and a side surface of the dummy wafer imitating the wafer; The method for cleaning a semiconductor device according to claim 14, wherein: