JPH10154686A - Method of cleaning semiconductor substrate processing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively remove foreign matters from a semiconductor substrate processing device without deteriorating it in operating efficiency by a method wherein a substrate to which self-adhesive material is fixed is transferred. SOLUTION: Self-adhesive materials 101, 104, and 105 are pasted on the primary surface, backside, and sides of a semiconductor wafer 103 so as to cover the wafer's wide area which comes into contact with a semiconductor processing device in transit. A double-sided adhesive tape releasing non-adhesive protrudent thin film 102 is fixed to the adhesive tape 101. A tape is replaced with a new one through such a manner that the non-adhesive thin film 102 is pulled to separate the adhesive tape 101 from the wafer 103, a new adhesive tape 101 is pasted in place of an old one, and reuse is realized. By this setup, a dummy wafer is deteriorated in foreign matter removing capacity with a decrease in cleanness as foreign matter deposited on the dummy wafer is increased in amount, but the dummy wafer is capable of easily recovering its original cleanness and being enhanced in foreign matter removing capability.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to apparatus cleaning, and more particularly, to a method of cleaning a substrate processing apparatus such as a semiconductor manufacturing apparatus and a semiconductor inspection apparatus.

[0002]

2. Description of the Related Art In a substrate processing apparatus, each processing section is connected by a transport system such as a belt type (A), a roller type (B), and a mechanical type (C) as shown in FIG. The system is a substrate,
It is transported by physical contact. At this time, if foreign matter adheres to the substrate, the foreign matter adheres to the belt 801 and the transfer arm 806 constituting the transfer system, and the foreign matter collects and causes dust. Then, there is a case where reverse contamination, that is, re-adhesion, occurs on a subsequent substrate, and if the substrate is required to have high cleanliness, it may cause a fatal defect in yield. In order to avoid this adverse effect, the transport system and each processing unit are periodically subjected to maintenance, that is, a cleaning process. However, the apparatus is stopped during that time, which causes a reduction in the operation rate. In particular, in an apparatus having such a transfer system in a vacuum chamber, maintenance is very complicated because it is necessary to disassemble and clean after shutting down the vacuum system. This was a significant factor.

In order to reduce the frequency and labor of the maintenance, there is a method in which a dummy substrate is transported empty between processing substrates to remove foreign substances that have adhered to a transport system or each processing section. It could not be said that the foreign matter removing effect was sufficient.

[0004]

As described above, in the conventional method of cleaning a substrate processing apparatus, the maintenance of the transport system and each processing section is periodically performed, that is, a cleaning process is performed. Had become. Further, in the method of carrying the dummy substrate empty, the effect of removing foreign substances cannot be said to be sufficient. SUMMARY OF THE INVENTION It is an object of the present invention to provide a method of cleaning a substrate processing apparatus which does not reduce the operation rate of the apparatus and improves the effect of removing foreign substances.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and is to perform cleaning in a substrate processing apparatus by transporting a substrate to which an adhesive substance is fixed.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a method for cleaning a semiconductor substrate processing apparatus according to the present invention will be described in detail with reference to FIGS.
1 and 2 show an example of a wafer structure to which an adhesive substance is fixed. Adhesion of foreign matter on the wafer is biased toward a portion where the wafer and the transfer path in the apparatus are in contact with each other, but the distribution is somewhat widened. Therefore, the main surface, back surface,
An adhesive substance (here, a double-sided adhesive tape) is attached to a wide area covering a portion that comes into contact in the side transport process. Here, the portion that comes into contact during the transport process is shown in FIG.
There are a contact portion with a wafer in a transfer system of a belt type, a roller type, a mechanical type, and the like, a claw or clamp for holding a wafer, a stopper for a wafer, a wafer chuck, and the like. 1A and 1B show an example of a wafer structure to which an adhesive tape used for cleaning a semiconductor substrate processing apparatus according to the present invention is fixed, and FIG. (B) is a sectional view. Adhesive substances (here, double-sided adhesive tapes) 101, 104, and 105 are applied over a wide range so as to cover portions that come into contact with the main surface, the back surface, and the side surface of the semiconductor wafer 103 in the transfer process. The foreign matter removal ability of the dummy wafer to which the adhesive tape is adhered deteriorates as the foreign matter adheres to the contact portion of the transport system and the processing unit. Therefore, it is necessary to restore the foreign matter removal ability by some method. is there. Here, the replacement of the tape is used as a means for restoring the ability of foreign matter. Therefore, the non-adhesive portion 102 for peeling the double-sided adhesive tape, which is a non-adhesive protrusion-like thin film, is fixed to the adhesive tape 101. The tape can be re-used by pulling the non-adhesive thin film 102 to peel off the adhesive tape 101 from the wafer 103 and attaching a new adhesive tape 101. The attachment and detachment of the above-mentioned adhesive substance may be performed by hand, or may be performed by a jig or an apparatus. 2A and 2B show a second embodiment of a wafer to which an adhesive tape used for cleaning the semiconductor substrate processing apparatus according to the present invention is fixed, and FIG. 2A is a perspective view in a state where each element is separated, (B) is a sectional view. Adhesive substances (here, double-sided adhesive tapes) 201, 204, and 205 are applied over a wide range so as to cover portions that come into contact with the main surface, the back surface, and the side surface of the semiconductor wafer 203 in the transfer process. FIG. 1 shows a case in which a tape coating on the back surface of the wafer is required in a donut shape, such as contact with a claw in the transfer process, whereas FIG. This shows a case where the entire back surface needs to be coated with a tape, such as contact with a chuck or the like. At this time, as described above,
In order to surely adsorb and remove foreign matters in the transport system of the apparatus and the portions in contact with the wafer in each processing section, the area where the wafer is covered with the tape is set to a wide range including the contact section. This range differs depending on the apparatus, and FIG. 3 shows an example of the range of the double-sided adhesive tape to be attached to the main surface of the wafer. FIG. 3 is a view showing a third example of the wafer to which the adhesive tape used for cleaning the semiconductor substrate processing apparatus according to the present invention is fixed.
FIG. 7A is a top view of the embodiment of the present invention. FIG. 7A shows a case where an adhesive tape is required at a donut-shaped portion around a wafer such as a clamp around the entire periphery. FIG. The case where an adhesive tape is required is shown. FIG. 4 is a cross-sectional view of a fourth embodiment of a wafer to which an adhesive tape used for cleaning the semiconductor substrate processing apparatus according to the present invention is fixed, and (A) is a cross-sectional view of the entire wafer. (B) is an enlarged sectional view of (A) a part. FIG. 4B shows a double-sided pressure-sensitive adhesive tape having a three-layer structure of a pressure-sensitive adhesive 402, a support 405, and a pressure-sensitive adhesive 404.
It is attached to both sides of. Examples of the material of the support include an acetate film (mat finish; Sumitomo 3M), polyethylene terephthalate (PET; Fujicolor), a fluororesin, a Teflon resin (Teflon skived tape), and the like. When necessary, a silicone-based pressure-sensitive adhesive is suitable, but when gas generation is allowed to some extent in a normal temperature and normal pressure process, an acrylic pressure-sensitive adhesive can be used. When the double-sided body shown in FIG. 4 is attached to the wafer, the peel strength (f1) of the adhesive tape on the substrate side is equal to or greater than the peel strength (f2) on the outermost surface side, that is, f1 ≧ f2.
It is necessary to be. The reason is that when f2 is larger than f1, there is a high risk that the double-sided tape itself peels off and adheres to the contact portion in the transporting process, which is not only against the purpose of removing foreign substances but also contaminates the transporting process. It is because it becomes. In the above example, a double-sided adhesive tape was used,
Other materials may be used as long as they are sticky thin films.
Next, FIG. 5 shows another example in which an adhesive is formed on a wafer by coating. 5A and 5B are cross-sectional views of an example of a wafer to which an adhesive substance used for cleaning the semiconductor substrate processing apparatus according to the present invention is fixed by coating. FIG. 5A is a cross-sectional view of the entire wafer, and FIG. (C) is an enlarged cross-sectional view of (A) part a, (B) is a single coating layer,
(C) shows a case where the coating layer has two layers, in which an acrylic or silicon-based adhesive is formed on both surfaces of the wafer. The reason why the adhesive layer is formed by two or more adhesives as shown in FIG. 5C is that the peel strength is f1 in the same manner as described above in order to avoid the danger of the adhesive substance from being contaminated during the transportation process. This is because it is necessary to select the material of each layer so as to satisfy the relationship of ≧ f2 (f1: peel strength of the pressure-sensitive adhesive on the substrate side, f2: peel strength of the pressure-sensitive adhesive on the outermost surface side). As a means for restoring the ability to remove foreign substances, the adhesive is peeled off by, for example, 02 asher or sulfuric acid / hydrogen peroxide treatment, and then applied again.

Next, an embodiment of a method for cleaning a semiconductor wafer processing apparatus according to the present invention will be described in detail with reference to FIG. In the semiconductor substrate processing apparatus, dust accumulates on a portion that comes into contact with the wafer 603 in the transfer process by repeating the transfer of the processed wafer 603, that is, on a transfer path, a claw of a wafer holding claw or a blade, or a wafer chuck (electrostatic chuck). In order to cause dust, the wafer 603 to which the above-mentioned adhesive substance is adhered is transported empty to the transport system of the wafer processing apparatus between the processing wafers. With the wafer 603 to be processed placed on the wafer cassette 601, the cassette chamber 6
02 in the cassette holder 607. When the cassette chamber 602 is evacuated and the pressure difference between the wafer loading chamber 605 and the wafer loading chamber 605 becomes lower than a predetermined value, the gate valve 606 separating the cassette chamber 602 and the wafer loading chamber 605 opens, and the wafer cassette 601 and the cassette holder 607 are moved together. It is transferred to the loading chamber 605. After the transfer is completed, the gate valve 606 is closed. Next, the etching chamber 608 and the wafer loading chamber 60
5 is opened to open the wafer cassette 6
The wafers 603 set at 01 are transferred one by one into the etching chamber 608. Hereinafter, the process of transferring and transferring the wafer 603 from the wafer loading chamber 605 to the etching chamber 608 will be described with reference to FIG. The wafer 703 lifted from the wafer cassette 701 by the blade 706 in FIG. 7A is held by the wafer holding claw 702 of the transfer arm 705 as shown in FIG. Goes down to its original position. Next, as shown in FIG. 7 (C), after the gate valve 708 is opened,
The wafer is transferred to a position directly above the wafer chuck (electrostatic chuck) 704 by the transfer arm 705, and the wafer chuck 704 is moved to this position, whereby the wafer is chucked by the wafer chuck 704, and the wafer chuck 704 is retracted. Thereafter, as shown in FIG. 7D, the transfer arm 705 moves to the wafer loading chamber 605 in order to avoid contact with the wafer 703. Thereafter, the gate valve 708 is closed, and etching of the wafer is started. In the transfer operation after the processing, the wafer 703 is transferred from the wafer chuck 704 to the wafer cassette 701 by the reverse operation. Regarding the frequency of the dummy wafer transfer processing to which the adhesive substance is fixed, the processing interval may be managed by time or the number of processing lots. Further, it may be transported only for the cleaning process. Further, the number of sheets is determined by the degree of contamination received from another process and the level of cleanliness required for the wafers to be processed until the next empty transfer. Therefore, weaving may be considered for every several wafers. In this manner, the transfer of the wafer to which the adhesive substance is fixed can be performed at an arbitrary time and in an arbitrary number.

Although the above description has been given of a processing apparatus having a vacuum chamber, it goes without saying that the present invention can be applied to a processing apparatus in the atmosphere. Further, the present invention can be applied to either a single wafer type or a batch type, and can also be applied to an apparatus for transferring a substrate other than a wafer such as a photomask or a reticle. In the above, the adhesive substance to be attached to the substrate is selected as described above in consideration of the adhesiveness and generation of gas. However, heat resistance, water resistance, and chemical resistance may be used according to the requirements of the apparatus and the processing substrate. Since various conditions such as properties and oiliness can be considered, it is needless to say that a material suitable for the purpose of use including the support should be selected.

[0009]

As described above, according to the present invention, it is possible to surely adsorb and remove a foreign substance at a portion in contact with a wafer in a transfer system and each processing section of a wafer processing apparatus. As a result,
Compared to the conventional method of performing maintenance manually, semi-automatic cleaning and in-situ cleaning of the wafer transfer path are achieved at a high cleanliness level, greatly reducing the burden on the operator, that is, the frequency and labor, In addition, it is possible to improve the operation rate. this is,
In particular, it is highly effective due to the difference in workability, such as the necessity of bringing down the vacuum system and then disassembling and cleaning the equipment using a vacuum system. Also, a high degree of effectiveness can be obtained for the same reason. In addition, this method allows loading at an arbitrary wafer number interval, and increases the frequency of loading of dummy wafers, thereby enabling real-time control of contamination control of a transfer path. In addition, in contrast to the conventional method of carrying dummy wafers by empty transfer, the number of dummy wafers to be used can be greatly reduced, so that the operation rate of the wafer processing apparatus can be improved. Further, according to the present invention, since the reliability of the cleanliness in the apparatus is improved, a stable product yield can be obtained.

In the present invention, since the non-adhesive projection-like thin film is fixed to the adhesive substance fixed to the dummy wafer, the adhesive substance can be easily peeled off. This makes it possible to reuse a dummy wafer to which an adhesive substance is fixed.

[Brief description of the drawings]

FIG. 1 shows an example of a wafer structure to which an adhesive tape used for cleaning a semiconductor substrate processing apparatus according to the present invention is fixed, and FIG. 1 (A) is a perspective view in a state where each element is separated; (B) is a sectional view.

FIG. 2 shows a second embodiment of a wafer to which an adhesive tape used for cleaning the semiconductor substrate processing apparatus according to the present invention is fixed, and FIG. 2 (A) is a perspective view in a state where each element is separated. , (B) are cross-sectional views.

FIG. 3 is a view showing a third example of a wafer to which an adhesive tape used for cleaning the semiconductor substrate processing apparatus according to the present invention is fixed.
FIGS. 3A and 3B are top views of the embodiment, in which FIG. 3A shows a case where an adhesive tape is required for a donut-shaped portion around the wafer, and FIG.

FIG. 4 is a cross-sectional view of a fourth embodiment of a wafer to which an adhesive tape used for cleaning the semiconductor substrate processing apparatus according to the present invention is fixed, wherein (A) is a cross-sectional view of the entire wafer, (B) is an enlarged sectional view of (A) a part.

FIGS. 5A and 5B are cross-sectional views of an example of a wafer to which an adhesive substance used for cleaning of the semiconductor substrate processing apparatus according to the present invention is fixed by coating; FIG. 5A is a cross-sectional view of the entire wafer; (C) is a cross-sectional view of (A) a part,
(B) shows the case where there is one coating layer, and (C) shows the case where there are two coating layers.

FIG. 6 is a sectional view of a schematic configuration of an apparatus for cleaning a semiconductor substrate processing apparatus according to an embodiment of the present invention.

FIG. 7 is an internal structural view related to wafer transfer of an apparatus for cleaning a semiconductor substrate processing apparatus according to an embodiment of the present invention, wherein (A), (B), (C), and (D) show wafers loaded; 2 shows the state of each sequence in the process.

FIG. 8 is a perspective view of a conventional general wafer transfer system.

[Explanation of symbols]

101 201 301 401 501: Double-sided adhesive tape to be attached to the main surface of the wafer 102 202: Non-adhesive portion for peeling off double-sided adhesive tape 103 203 403 503 603 7
03: Semiconductor wafer 104 204: Double-sided adhesive tape to be attached to the back of the wafer 105 205: Double-sided adhesive tape to be attached to the side of the wafer 301: Tape attachment range on the wafer surface 302: Wafer end 401: Double-sided tape 402 502: Adhesive 1 404 504: Adhesive 2 405 505: Support 601 701: Wafer cassette 602: Cassette chamber 604 704: Wafer chuck 605: Wafer loading chamber 606 708: Gate valve 607: Cassette holder 608: Etching chamber 702: Wafer holding claw 705 : Wafer transfer arm 706: Wafer transfer blade 707: Wafer transfer blade tab 709: Chamber wall 801: Belt 802: Pulley 804: Drive motor 05: Roller 806: transfer arm 807: wafer contact surface 808: Vacuum holes 809: slide box 810: slide stage

Claims (8)

[Claims] 1. A method of cleaning a substrate processing apparatus, comprising: transporting a substrate having an adhesive substance adhered to at least one of a front surface, a rear surface, and a side surface into a substrate processing apparatus main body. 2. The cleaning method according to claim 1, wherein the sticky substance is a tape-like thin film having stickiness. 3. The cleaning method according to claim 1, wherein a non-adhesive protruding substance is fixed to the adhesive substance. 4. The cleaning method according to claim 2, wherein the peel strength of the tape-shaped thin film on the substrate side is equal to or greater than the peel strength on the surface side. 5. The cleaning method according to claim 1, wherein said adhesive substance is one coated with an adhesive. 6. The cleaning method according to claim 5, wherein said adhesive has a laminated structure in which at least two or more adhesives having different peel strengths are applied. 7. The cleaning method according to claim 6, wherein the pressure-sensitive adhesive has a peel strength of the pressure-sensitive adhesive on the substrate side equal to or greater than a peel strength of the pressure-sensitive adhesive on the surface side. 8. A method for cleaning a substrate processing apparatus, comprising: transferring a dummy wafer having an adhesive substance adhered to at least one of the front, rear, and side surfaces to a transfer path in a substrate processing apparatus main body.