JP2008042099A - Cleaning device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cleaning device which accelerates a processing speed of a wafer based on wafer per unit floor space, notably improves its operation rate by carrying out various kinds of cleaning treatment on a wafer after polishing, enables interchange or rearrangement of a plurality of cleaning treatment baths into a best arrangement depending on a cleaning process, etc. and can further simplify a device configuration without causing a defect on a wafer in pre-process, etc. <P>SOLUTION: According to the present invention, a cleaning device comprising cleaning lines 2A and 2B each composed of a plurality of cleaning treatment baths 2a-2d and 2e-2h on two layers of upper and lower layers, a center conveying means 6 having functions of carrying in the polished wafer and carrying out the processed wafer for each cleaning treatment baths 2a-2h in the lower and upper layers of cleaning lines 2A and 2B, and a conveying means between baths 9 which sequentially conveys wafers to the adjacent cleaning treatment baths in the upper and lower layers of each cleaning line 2A and 2B. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a cleaning apparatus, and more particularly, to a cleaning apparatus that cleans a wafer after polishing by chemical mechanical polishing (CMP) or the like.

  Wafers such as semiconductor devices and electronic components are subjected to various processes such as cutting and polishing in the course of manufacturing. In recent years, with the development of semiconductor technology, miniaturization of design rules of semiconductor integrated circuits and multilayer wiring have progressed, and in order to reduce costs, the diameter of wafers has also increased. For this reason, when the pattern of the next layer is formed as it is on the layer on which the pattern is formed as in the prior art, it becomes difficult to form a good pattern in the next layer due to the unevenness of the previous layer, and defects, etc. Is likely to occur.

  For this reason, a planarization process is performed in which the surface of the layer on which the pattern is formed is planarized, and then the pattern of the next layer is formed. CMP is frequently used in this planarization process. Polishing a wafer by CMP holds the wafer by a polishing head, presses the wafer against the polishing pad while supplying a slurry, which is a mixture of an abrasive and a chemical, and rotates the wafer and / or polishing pad in this state. Is done.

  A large amount of particles such as used abrasives, metal impurities contained in chemicals, and metal ions and fine particles used for metal wiring on the wafer adhere to the wafer surface after polishing by CMP. Yes. Since these particles and the like adversely affect the semiconductor device or the like as a product, it is necessary to clean the surface of the polished wafer to remove particles, metal impurity ions, fine particles, and the like.

  As a conventional technique related to such a cleaning apparatus, for example, the following polishing apparatus and substrate processing apparatus are known. In this prior art, four primary to quaternary cleaning machines (cleaning treatment tanks) for cleaning a wafer after CMP polishing are arranged in one direction. Further, a moving mechanism for sequentially transferring the wafers to the next cleaning machine is provided. The primary and secondary cleaning machines rotate and roll-up sponges arranged on the top and bottom and press them against the front and back surfaces of the wafer to clean the front and back surfaces of the wafer. The tertiary cleaning machine cleans the wafer by pressing it against the wafer while rotating a hemispherical sponge. The quaternary cleaning machine cleans the back surface of the wafer by rinsing and pressing the front surface while rotating a hemispherical sponge. A spin dry function for drying the wafer by rotating it at a high speed after the cleaning is provided (for example, see Patent Document 1).

Further, as another conventional technique related to the cleaning apparatus, for example, the following substrate processing method is known. In this prior art, first to fourth cleaning treatment tanks for cleaning a wafer after CMP polishing are arranged in one direction. In addition, a transfer device for sequentially transferring the wafers to the next cleaning tank is provided. The first cleaning tank is cleaned while supplying an organic alkaline processing liquid to both front and back surfaces of the wafer. The second cleaning treatment tank cleans the wafer with an organic acidic treatment liquid. In the third cleaning treatment tank, pure water is supplied to the front surface of the wafer to form a liquid film, and a high oxidizing power treatment solution is supplied to the back surface of the wafer to perform cleaning. And a 4th washing process tank finishes and cleans the front and back both surfaces of a wafer with an ultrasonic wave, and spin-drys after that (for example, refer patent document 2).
JP2003-309089A (18th and 19th pages, FIG. 1). JP 2002-299300 A (page 5, FIG. 2).

  In the prior arts described in Patent Documents 1 and 2, the wafers after polishing by CMP are cleaned while sequentially transporting each cleaning processing tank, and dried in the final cleaning processing tank to finish the cleaning process. . At this time, since the wafers are sequentially processed one by one in the four cleaning processing tanks arranged in one direction, the cleaning time of the cleaning processing tank having the longest processing time among the four cleaning processing tanks is used. The number of processed sheets per unit time of the entire cleaning apparatus is limited. Further, when the wafer cleaning process is stopped due to a failure of one of the four cleaning processing tanks or the like, a processing defect occurs in the in-process wafer such as pre-processing. Furthermore, the cleaning apparatus has a structurally fixed transfer order from the first cleaning tank to the final cleaning tank, and the processing order cannot be changed according to the cleaning process or the like.

  Therefore, various types of cleaning processes are performed on the polished wafers to increase the processing speed of the wafers per unit floor area and to significantly improve the operation rate, and to optimize the multiple cleaning tanks according to the cleaning process etc. It is possible to replace or rearrange them into a proper arrangement, and there is no technical problem to be solved in order to simplify the equipment configuration without causing defects to the wafers in process such as pretreatment. Therefore, an object of the present invention is to solve this problem.

  The present invention has been proposed to achieve the above object, and the invention according to claim 1 includes a cleaning line provided with a plurality of cleaning processing tanks for performing a required cleaning process and drying on a polished wafer. A central transfer means having two stages of a lower layer and an upper layer, and having a function of loading the polished wafer and a function of unloading the processed wafer to each cleaning treatment tank in the lower and upper layer cleaning lines, In addition, a cleaning apparatus is provided having inter-tank transport means for sequentially transporting wafers to adjacent cleaning processing tanks in the lower and upper cleaning lines.

  According to this configuration, when a series of processing is performed only in the lower cleaning line, the wafer after polishing by chemical mechanical polishing or the like is carried into the cleaning processing tank on the upstream side in the lower cleaning line by the central transfer means. The carried wafers are sequentially transported to adjacent cleaning processing tanks by inter-tank transporting means, are subjected to a required cleaning process, and are subjected to a drying process in the final cleaning processing tank and are carried out.

  When a series of processing is performed only in the upper cleaning line, the polished wafer is carried into the upstream cleaning tank in the upper cleaning line by the central transfer means. The carried wafers are sequentially transported to adjacent cleaning processing tanks by inter-tank transporting means, are subjected to a required cleaning process, and are subjected to a drying process in the final cleaning processing tank and are carried out.

  In the case where the processing is continuously performed from the lower layer cleaning line to the upper layer cleaning line, the polished wafer is carried into the preceding stage cleaning processing tank in the lower layer cleaning line by the central transfer means. The loaded wafer is subjected to a necessary cleaning process while being sequentially transported to the adjacent cleaning processing tank by the inter-tank transporting means, and unloaded by the central transporting means in the subsequent cleaning processing tank. Further, it is carried by the central transfer means into a cleaning tank on the upstream side in the upper cleaning line. The loaded wafer is subjected to a necessary cleaning process while being sequentially transferred to an adjacent cleaning process tank by an inter-tank transfer means, and is dried and carried out in a final cleaning process tank in the upper cleaning line.

  When processing is performed in parallel in the lower cleaning line and the upper cleaning line, the polished wafer is carried into the cleaning tank on the previous stage in the lower cleaning line by the central transfer means, and the required cleaning processing and drying are performed. Carried out and carried out. In parallel with this, the other polished wafers are carried into the upstream cleaning tank in the upper cleaning line by the central transfer means, and are carried out after necessary cleaning and drying. In this way, the lower and upper cleaning lines are simultaneously operated to perform parallel processing of wafers.

  According to a second aspect of the present invention, there is provided a cleaning apparatus in which any one of the lower and upper cleaning lines can be operated even if the other cleaning line is stopped.

  According to this configuration, even if one of the lower and upper cleaning lines is stopped for some reason, the cleaning process is performed on the other cleaning line. Therefore, the cleaning processing function as the whole apparatus is always maintained.

  According to a third aspect of the present invention, there is provided a cleaning apparatus in which each cleaning processing tank in the lower and upper cleaning lines has substantially the same outer shape and can be replaced with another cleaning processing tank.

  According to this configuration, it is possible to replace or rearrange a plurality of cleaning tanks in each of the lower and upper cleaning lines so as to obtain a more optimal cleaning function according to the wafer cleaning process and the like. Become.

  According to the first aspect of the present invention, the cleaning line having a plurality of cleaning processing tanks for performing required cleaning processing and drying on the polished wafer is configured in two stages, a lower layer and an upper layer, and the lower layer and the upper layer are cleaned. Central cleaning means having a function of carrying in the wafer after polishing and a function of carrying out the processed wafer with respect to each cleaning processing tank in the line, and a wafer to the cleaning processing tank adjacent in each of the lower and upper cleaning lines Since the inter-tank transfer means is provided, the processing is performed only by the lower layer cleaning line, by the upper layer cleaning line alone, or continuously from the lower layer cleaning line to the upper layer cleaning line. Therefore, the wafer after polishing can be subjected to various cleaning processes. Moreover, parallel processing can be performed in the lower and upper cleaning lines, the processing speed of wafers per unit floor area can be increased, the operating rate can be remarkably improved, and the cleaning processing is different. Various wafers can be processed simultaneously. In addition, there is an advantage that the wafer configuration can be directly carried in and out of the lower and upper layer cleaning processing tanks by a common central transfer means, and the apparatus configuration can be simplified.

  The invention according to claim 2 is a cleaning processing function as a whole apparatus because any one of the lower and upper cleaning lines can be operated even if the other cleaning line is stopped. Is always maintained, so that there is an advantage that a defect is not generated in a pre-processed wafer.

  The invention according to claim 3 is that the cleaning tanks in the lower and upper cleaning lines have substantially the same outer shape and can be replaced with other cleaning tanks. There is an advantage that it can be replaced or rearranged in a more optimal arrangement according to the wafer cleaning process or the like.

  Various types of cleaning processes are performed on the polished wafers to increase the processing speed of the wafers per unit floor area and to significantly improve the operation rate. Multiple cleaning tanks can be arranged more optimally according to the cleaning process etc. In order to achieve the purpose of making it possible to replace or rearrange the wafers and to prevent in-process wafers such as pretreatments from occurring and to further simplify the apparatus configuration, The cleaning lines each having a plurality of cleaning treatment tanks for performing the required cleaning treatment and drying are configured in two stages, a lower layer and an upper layer, and each polishing treatment tank in the lower and upper layer cleaning lines is subjected to the polishing A central transfer means having a function of carrying in a wafer and a function of carrying out a processed wafer, and an adjacent cleaning process in each of the lower and upper cleaning lines. It was achieved by including the vat between conveying means for sequentially conveying the wafer to the bath.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a view showing a cleaning device, in which (a) is a plan view and (b) is a side view.

  First, the configuration of the cleaning apparatus according to the present embodiment will be described. In FIG. 1, the cleaning device 2 is installed in the chemical mechanical polishing device 1. The chemical mechanical polishing apparatus 1 mainly includes a load port unit 3, a polishing apparatus 4, a first transfer machine 5, a central transfer machine 6 as a central transfer means, an optional chamber 7, and an apparatus control (not shown) in addition to the cleaning apparatus 2. It consists of parts.

  The load port unit 3 includes product wafer load ports 3a and 3a, a dummy wafer load port 3b, and a monitor wafer load port 3c. Each load port 3a, 3b and 3c stores a plurality of wafers W, respectively. A cassette 8 is placed.

  The polishing apparatus 4 is provided to be movable in the arrangement direction of three platens 4a, 4b, and 4c arranged on one side of the chemical mechanical polishing apparatus 1 and the three platens 4a, 4b, and 4c. It is composed mainly of two polishing heads (not shown). Each platen 4a, 4b, 4c is formed in a disk shape, and rotates in one direction by driving a motor (not shown). A polishing pad is attached to the upper surface of each of the platens 4a, 4b, 4c, and slurry is supplied onto the polishing pad from a nozzle (not shown).

  Of the three platens 4a, 4b, 4c, the left and right platens 4a, 4c are used for polishing a first polishing target film (for example, a Cu film), and the central platen 4b is a second polishing target film (for example, for example). Ta film) is used for polishing. In both types of polishing, the type of slurry to be supplied, the rotational speed of the polishing head, the rotational speed of the platens 4a, 4b, and 4c, the pressing force of the polishing head, the material of the polishing pad, and the like are changed.

  In the polishing apparatus 4, the wafer W is held by the polishing head, and the wafer W is pressed against the polishing pad while supplying slurry onto the polishing pad from the nozzle. In this state, the platens 4a, 4b, 4c and the polishing head are connected to each other. Each is rotated to perform chemical mechanical polishing of the wafer W.

  The cleaning device 2 is disposed on the other side of the chemical mechanical polishing device 1 so as to face the polishing device 4. The cleaning device 2 is configured in two stages, a lower layer cleaning line 2A having four cleaning processing tanks 2a to 2d and an upper layer cleaning line 2B having four cleaning processing tanks 2e to 2h. Has been.

  The four cleaning processing tanks 2a to 2d in the lower cleaning line 2A are, for example, a cleaning processing tank 2a for cleaning the front and back surfaces of the wafer W with a sponge brush and spraying steam on the front and back surfaces of the wafer W. Cleaning processing tank 2b for cleaning, cleaning processing tank 2c for cleaning the wafer W with ultrasonic waves, cleaning the surface of the wafer W with a chemical solution to remove remaining dust, rinse cleaning, and finally spin drying It is comprised by the processing tank 2d.

  The four cleaning treatment tanks 2e to 2h in the upper cleaning line 2B are configured in substantially the same manner as the four cleaning treatment tanks 2a to 2d in the lower cleaning line 2A.

The cleaning tanks 2a to 2h in the lower and upper cleaning lines 2A and 2B can be replaced or rearranged with cleaning tanks having substantially the same outer shape and other cleaning functions. Further, the lower and upper cleaning lines 2A and 2B are configured so that at least one of them always operates.

  Between the cleaning treatment tanks 2a to 2h in the lower and upper cleaning lines 2A and 2B, an inter-tank transfer machine 9 is installed as inter-tank transfer means. The inter-vessel transfer device 9 sequentially transfers the wafers W to adjacent cleaning processing tanks (for example, 2a and 2b).

  The first transfer device 5 takes out the unpolished wafer W from the cassette 8 placed on the product wafer load ports 3a, 3a and transfers it to the wafer standby position 10. In addition, the first transfer device 5 receives the wafer W cleaned in the lower and upper cleaning lines 2A and 2B directly from the final cleaning tank 2d or 2h and sends it to the product wafer load ports 3a and 3a. Carry in.

  The central transfer device 6 receives an unpolished wafer W from the wafer standby position 10 and carries it into the polishing apparatus 4 via the delivery position 11. Further, the polished wafer W is received via the delivery position 11 and carried into the cleaning treatment tanks 2a to 2h in the lower and upper cleaning lines 2A and 2B. The central transfer device 6 has a function of directly loading / unloading the wafer W to / from any of the cleaning tanks 2a to 2h in the lower and upper cleaning lines 2A and 2B. For this reason, each of the cleaning treatment tanks 2a to 2h in the lower and upper cleaning lines 2A and 2B is provided with a front transfer port 12 for carrying the wafer W in and out.

  The optional chamber 7 performs predetermined processing and film thickness measurement on the wafer W before polishing, after polishing, and after cleaning processing in addition to the polishing and cleaning processing, and then transfers the wafer W to the central transfer device 6. It has a function of delivering and transporting to the next required process via the central transporter 6. The optional chamber 7 is also provided with a front transfer port 12 for loading and unloading the wafer W.

  Next, the operation of the cleaning apparatus configured as described above will be described. In the cleaning apparatus of this embodiment, the cleaning lines 2A and 2B are configured in two stages, ie, the lower layer and the upper layer, so that (a) a series of cleaning processes are performed only with the lower cleaning line 2A. A series of cleaning processes are performed only with 2B. (C) The cleaning process is performed continuously from the lower cleaning line 2A to the upper cleaning line 2B. (D) The lower cleaning line 2A and the upper cleaning line 2B are parallel. Various kinds of cleaning treatment modes can be taken such as performing a cleaning treatment. Hereinafter, this will be described in order.

  (A) When a series of cleaning processes are performed only in the lower cleaning line 2A. In this case, the wafer W that has been subjected to chemical mechanical polishing by the polishing apparatus 4 is received by the central transfer device 6 via the transfer position 11, and is carried into the cleaning treatment tank 2a on the starting end side in the lower cleaning line 2A. The The transferred wafer W is sequentially transported to the adjacent cleaning processing tanks 2b, 2c, and 2d by the inter-tank transfer device 9, and is subjected to a necessary cleaning process, and a drying process is performed in the final cleaning process tank 2d. Exit.

  After the completion of the cleaning process, the wafer W is directly transferred from the final cleaning tank 2d to the first transfer device 5 and carried into the product wafer load ports 3a and 3a.

  (B) When performing a series of cleaning processes only in the upper cleaning line 2B. In this case, the wafer W that has been subjected to chemical mechanical polishing is directly carried into the cleaning treatment tank 2e on the start end side in the upper cleaning line 2B by the central transfer device 6. The transferred wafer W is sequentially transferred to the adjacent cleaning processing tanks 2f, 2g, and 2h by the inter-tank transfer device 9, and is subjected to a required cleaning process, followed by a drying process in the final cleaning process tank 2h. Exit.

  After completion of the cleaning process, the wafer W is directly transferred from the final cleaning tank 2h to the first transfer device 5 and carried into the product wafer load ports 3a and 3a.

  (C) When performing a cleaning process continuously from the lower cleaning line 2A to the upper cleaning line 2B. In this case, the wafer W subjected to the chemical mechanical polishing is first carried into the cleaning treatment tank 2a on the start end side in the lower cleaning line 2A by the central transfer device 6. The loaded wafer W is sequentially transferred to the adjacent cleaning processing tanks 2b, 2c, and 2d by the inter-tank transfer device 9, and a required cleaning process is performed.

  Then, the stage where the cleaning process is performed only in the cleaning process tank 2a on the start side, the stage where the cleaning process is performed in the two cleaning process tanks 2a and 2b, and the cleaning process in the three cleaning process tanks 2a, 2b and 2c At either the stage where the process is performed or the stage where the cleaning process is performed up to the final cleaning process tank 2d, the wafer W is transferred from the corresponding cleaning process tank 2a, 2b, 2c or 2d by the central transfer device 6. It is carried out. Subsequently, it is carried into the cleaning treatment tank 2e on the start end side in the upper cleaning line 2B by the central transfer device 6.

  The wafer W carried into the upper cleaning line 2B is sequentially transferred to the adjacent cleaning processing tanks 2f, 2g, and 2h by the inter-tank transfer device 9, and is subjected to a required cleaning process, and then dried in the final cleaning processing tank 2h. And the cleaning process from the lower cleaning line 2A to the upper cleaning line 2B is completed.

  After the completion of the cleaning process, the wafer W is transferred from the final cleaning tank 2h in the upper cleaning line 2B to the first transfer device 5 and carried into the product wafer load ports 3a and 3a.

  (D) When the cleaning process is performed in parallel on the lower cleaning line 2A and the upper cleaning line 2B. In this case, the wafer W on which chemical mechanical polishing has been performed is carried into the cleaning treatment tank 2a on the start end side in the lower cleaning line 2A by the central transfer device 6. The loaded wafer W is sequentially transferred to the adjacent cleaning processing tanks 2b, 2c, and 2d by the inter-tank transfer device 9, and a required cleaning process is performed. The wafer W that has been subjected to the cleaning process is transferred from the final cleaning tank 2d to the first transfer device 5 and carried into the product wafer load ports 3a and 3a.

  In parallel with this, another wafer W that has been subjected to chemical mechanical polishing is carried by the central transfer device 6 into the cleaning treatment tank 2e on the starting end side in the upper cleaning line 2B. The loaded wafer W is sequentially transferred to the adjacent cleaning processing tanks 2f, 2g, and 2h by the inter-tank transfer device 9, and a required cleaning process is performed. The wafer W that has been subjected to the cleaning process is transferred from the final cleaning tank 2h to the first transfer device 5 and carried into the product wafer load ports 3a and 3a. In this way, the lower and upper cleaning lines 2A and 2B are simultaneously operated to perform parallel processing of the wafer W.

  As described above, the cleaning baths 2a to 2d in the lower cleaning line 2A and the cleaning baths 2e to 2h in the upper cleaning line 2B are configured to have substantially the same cleaning processing function. . The lower and upper cleaning lines 2A and 2B are configured so that at least one of them always operates.

  For this reason, in the case where the cleaning process is performed only by the lower layer cleaning line 2A or the upper layer cleaning line 2B, if one of the cleaning lines is stopped for some reason, the cleaning process is executed. By switching to the cleaning line, the required cleaning process can be performed without any trouble.

  Further, the cleaning tanks 2a to 2d and 2e to 2h in the lower and upper cleaning lines 2A and 2B can be replaced or rearranged with cleaning tanks having substantially the same outer shape and other cleaning functions. Yes. For this reason, it is possible to appropriately change the cleaning processing function of each cleaning line 2A or 2B by replacing or rearranging the cleaning processing tanks 2a to 2d and 2e to 2h.

  As described above, in the cleaning apparatus according to the present embodiment, various cleaning processes can be performed on the wafer W after chemical mechanical polishing, such as a continuous process from the lower cleaning line 2A to the upper cleaning line 2B. it can.

  Parallel processing can be performed in the lower and upper cleaning lines 2A and 2B, the processing speed of the wafers W per unit floor area can be increased, and the operating rate can be remarkably improved.

  Various types of wafers W having different cleaning processes can be processed simultaneously.

  Loading and unloading of the wafers W with respect to the lower and upper cleaning tanks 2a to 2h can be performed directly by the common central transfer device 6, and the apparatus configuration can be simplified.

  Since the cleaning processing function of the entire cleaning apparatus is always maintained, defects in the in-process wafer W such as preprocessing do not occur.

  In addition, the plurality of cleaning processing tanks 2a to 2d and 2e to 2h in the cleaning lines 2A and 2B can be replaced or rearranged in a more optimal arrangement according to the cleaning processing process of the wafer W or the like.

  The present invention can be variously modified without departing from the spirit of the present invention, and the present invention naturally extends to the modified ones.

It is a figure which shows the washing | cleaning apparatus which concerns on the Example of this invention, (a) is a top view, (b) is a side view.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Chemical mechanical polishing apparatus 2 Cleaning apparatus 2A Lower layer cleaning line 2B Upper layer cleaning line 2a-2h Cleaning process tank 3 Load port part 4 Polishing apparatus 5 1st conveyance machine 6 Central conveyance machine (central conveyance means)
7 Optional chamber 8 Cassette 9 Inter-tank transporter (inter-tank transport means)
10 Wafer standby position 11 Delivery position 12 Front transfer port W Wafer

Claims (3)

  The cleaning line having a plurality of cleaning processing tanks for performing necessary cleaning processing and drying on the polished wafer is configured in two stages, a lower layer and an upper layer, and for each cleaning processing tank in the lower layer and upper layer cleaning lines A central transfer means having a function of carrying in the polished wafer and a function of taking out the processed wafer, and an inter-bath transfer means for sequentially transferring the wafers to adjacent cleaning treatment tanks in each of the lower and upper cleaning lines. And a cleaning device.   2. The cleaning apparatus according to claim 1, wherein even if one of the lower and upper cleaning lines is stopped, the other cleaning line can be operated.   3. The cleaning apparatus according to claim 1, wherein each of the cleaning tanks in the lower and upper cleaning lines has substantially the same outer shape and can be replaced with another cleaning tank.

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