JP2007150359A - Device and method for preventing oxidation reforming on wafer surface - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent wafer residence, and oxidation and reforming on a wafer surface even if troubles occur in a polishing device. <P>SOLUTION: A device prevents the oxidation and reforming on the surface of a wafer that stayed by the troubles occurring in a wafer polishing device. The wafer polishing device comprises at least a polishing means for performing CMP polishing to a conveyed wafer; a cleaning means for cleaning the conveyed wafer; a drying means for drying the conveyed wafer; and a conveyance means for conveying the wafer to the polishing, cleaning, and drying means in this order. The device comprises a detection means for detecting the occurrence of the troubles, a wafer storage chamber filled with an inactive liquid, and a wafer retraction means for carrying the wafer in the wafer storage chamber when the occurrence of the troubles is detected by the detection means. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a wafer surface oxidation reforming prevention apparatus and a wafer surface oxidation reforming prevention method, and more particularly to a wafer surface oxidation reforming prevention apparatus and a wafer surface oxidation reforming prevention method in an inert gas atmosphere. About.

  In recent years, with the development of semiconductor technology, the miniaturization of design rules and the formation of multilayer wiring have progressed. The Cu damascene structure usually formed on the surface of a semiconductor wafer has a Cu film as a wiring film formed on the surface, and a TaN film or Ta film as a barrier film is formed below it, and further a barrier film Below is an oxide film. Therefore, in CMP (Chemical Mechanical Polishing) of Cu, the Cu film is first removed by polishing, and then the barrier film such as TaN film is polished and removed. Yes.

  A wafer to be polished is taken out from a dedicated cassette by handling means such as an indexing robot, and after passing through a film thickness measuring process, is transferred to a polishing process for removing the Cu film and the TaN film. Assuming that the process of removing the Cu film is the first step and the process of removing the TaN film is the second step, the Cu removal process of the first step removes Cu and finishes polishing when TaN comes out. Move on to the step. Generally, in the TaN removal process of the second step, a slurry that polishes TaN relatively well is used. Therefore, the first step and the second step are not processed by the same polishing pad, and separate polishing means are used. Is processed. After the polishing in the second step, the film is again passed through the film thickness measurement process through the rough cleaning process, the precision cleaning process, the rinsing process, and the drying process for removing the polishing slurry and the polishing powder. Store in cassette.

  The wafer surface after polishing is oxidized or modified during the wafer transfer process, rough cleaning process, precision cleaning process, rinse process, drying process, and film thickness measurement process after this polishing process. Is a problem. In particular, a metal material such as Cu, Al, or W used as a conductor of the wiring material has a property that a portion in contact with the outside air is easily oxidized. In recent years, since the wiring portion is miniaturized, the surface area is large for the cross-sectional area. This oxidation of the surface of the wiring material leads to a significant decrease in the electrical conductivity and high frequency characteristics of the wiring and greatly affects the quality of the final product. For example, the wiring width and the wiring depth of Cu are on the order of 0.1 μm, but if the wiring is further miniaturized in the future, the degree of oxidation of the surface of the wiring material will become a big problem.

  Further, in the wafer polishing process, when the product stays due to some trouble of the apparatus or the workpiece, the wafer surface is oxidized or modified to cause a problem that the quality of the wafer is deteriorated.

  In the polishing process of the wafer surface, a polishing slurry that chemically reacts with a wiring material such as Cu as a film to be polished and performs fine etching is used. In addition, a cleaning chemical that chemically reacts with a wiring material such as Cu to perform fine etching is also used. The time during which such polishing slurry and cleaning chemicals are acting on the wafer surface must be managed very strictly. If it is left in a state where it has been infiltrated for a long time by such a liquid, the surface of the wafer is chemically modified such as etching of copper, and the conductivity of the wiring is lowered, and in some cases, the wiring is broken. There was a problem of causing a failure and becoming a defective product.

  Thus, the conventional CMP system has a problem of oxidation or modification after polishing, and an example thereof is introduced in the following documents.

Reference materials: The latest CMP process and material technology Toshiro Dohi, Masaharu Kinoshita Technical Information Association pages 257, 261, 272, etc.

Reference Material: Electronic Materials VOL. 40 No. 3 96 pages, etc.

  The present invention has been made in view of such circumstances, and prevents oxidation and modification of the wafer surface in each process such as a conveyance process, a cleaning process, a drying process, an inspection process, and a storage process after polishing. It is an object of the present invention to provide a wafer surface oxidation reforming prevention apparatus and a wafer surface oxidation reforming prevention method that can be applied.

  In addition, even if trouble occurs in the polishing apparatus, the present invention is in an atmospheric exposure state in the polishing process, immediately after the polishing process, the transport process after the polishing process, the cleaning process, the drying process, the inspection process, the storage process, etc. It is possible to prevent stagnation of the wafer and prevent oxidation and modification of the wafer surface.

  In order to achieve the above object, the invention described in claim 1 is characterized in that at least a polishing means for CMP polishing the transferred wafer, a cleaning means for cleaning the transferred wafer, and a drying for drying the transferred wafer. In an apparatus for preventing oxidation or modification of the surface of a wafer that has accumulated due to a trouble that has occurred in a wafer polishing apparatus comprising: means; and a conveying means that conveys the wafer in order of the polishing means, the cleaning means, and the drying means Detecting means for detecting the occurrence of trouble, a wafer storage chamber filled with an inert liquid, and when the detection means detects the occurrence of the trouble, the wafer is retracted into the wafer storage chamber. And means.

  According to the first aspect of the present invention, even when a trouble occurs in the polishing apparatus, it is possible to prevent the wafer from staying and prevent the wafer surface from being oxidized or modified.

  According to a second aspect of the present invention, when the occurrence of the trouble is detected by the detection means, the wafer retracting means stores the wafer being polished or polished by the polishing means in the wafer storage chamber. It is characterized by that.

  Further, in the invention described in claim 3, in the invention described in claim 1 or 2, the wafer evacuation unit is performing cleaning or cleaning by the cleaning unit when the occurrence of the trouble is detected by the detection unit. A later wafer is stored in the wafer storage chamber.

  According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, when the occurrence of the trouble is detected by the detecting means, the wafer saving means is dried by the drying means. A wafer stored inside or after drying is stored in the wafer storage chamber.

  According to a fifth aspect of the present invention, in the invention according to any one of the first to fourth aspects, when the occurrence of the trouble is detected by the detecting means, the wafer retracting means is The wafer being transferred is stored in the wafer storage chamber.

  The invention according to claim 6 is the invention according to any one of claims 1 to 5, characterized in that the inert liquid flows in the wafer storage chamber.

  The invention according to claim 7 is the invention according to any one of claims 1 to 6, wherein the inert liquid is pure water.

  The invention described in claim 8 includes at least a polishing unit for CMP polishing the transferred wafer, a cleaning unit for cleaning the transferred wafer, a drying unit for drying the transferred wafer, and a wafer. In the method for preventing oxidation and modification of the surface of the wafer staying in the wafer polishing apparatus having the polishing means, the cleaning means, and the transfer means for transferring in order of the drying means, the occurrence of the trouble And a trouble detection step for detecting, and a wafer evacuation step for storing the wafer in a wafer storage chamber filled with an inert liquid when the occurrence of the trouble is detected.

  According to the eighth aspect of the present invention, even when a trouble occurs in the polishing apparatus, it is possible to prevent the wafer from staying and to prevent the wafer surface from being oxidized or modified.

  As described above, according to the present invention, even when a trouble occurs in the polishing apparatus, it is possible to prevent the wafer from staying and to prevent the wafer surface from being oxidized or modified.

  According to another aspect of the invention, a wafer storage chamber for temporarily storing a wafer and blocking the wafer from the outside air, and an inert substance such as an inert gas or an inert liquid are filled in the wafer storage chamber. Inert substance filling means and wafer carry-in means for carrying the wafer into the wafer storage chamber, so that during the polishing process, immediately after the polishing process, after the polishing process, a cleaning process, a drying process, an inspection process, It is possible to prevent oxidation or modification of the wafer surface in the storage process or the like.

  According to another aspect of the invention, there is provided a detecting means for detecting a trouble occurring in the polishing apparatus, and the wafer carry-in means carries the wafer into the wafer storage chamber when the detecting means detects a trouble occurring in the polishing apparatus. As a result, even if trouble occurs in the polishing apparatus, exposure to the atmosphere during the polishing process, immediately after the polishing process, transport process after the polishing process, cleaning process, drying process, inspection process, storage process, etc. It is possible to prevent the wafer from staying in the state, and to prevent oxidation and modification of the wafer surface.

  According to another aspect of the invention, as the inert liquid used in the polishing apparatus, dissolved oxygen of 0.1 ppm to 1 ppm or ultrapure water having a specific resistance of 16 M ohm to 30 MΩ is used. Therefore, it becomes possible to prevent the wafer surface from being oxidized or modified at a low cost.

  According to another invention, a detecting means for detecting a trouble occurring in the polishing apparatus, a storage chamber for temporarily storing a wafer and a wafer storage chamber for shielding the wafer from outside air, and the wafer storage chamber An inert substance filling means for filling an inert substance such as an inert gas or an inert liquid, a wafer carry-in means for carrying a wafer into the wafer storage chamber, and the detection means detecting a trouble occurring in the polishing apparatus; Control means for outputting an instruction to carry the wafer into the wafer storage chamber to the wafer carry-in means, so that even if a trouble occurs in the polishing apparatus, polishing is performed during the polishing process or immediately after the polishing process. Prevents wafer stagnation in post-processing transport, cleaning, drying, inspection, storage, etc. It is possible to prevent or reformed.

  Preferred embodiments of a wafer surface oxidation reforming prevention apparatus and wafer surface oxidation reforming prevention method according to the present invention will be described below in detail with reference to the accompanying drawings. In addition, in each figure, the same number or symbol is attached | subjected about the same member.

  FIG. 1 shows an external perspective view of a wafer surface oxidation reforming prevention apparatus according to the present invention.

  As shown in the figure, the transfer process section, the cleaning process section, and the like in the wafer polishing apparatus 10 are covered with walls, windows, and doors, and the outside and the inside of the wafer polishing apparatus 10 are transferred during the transfer of the wafer W and during the cleaning process. For example, the inside of the wafer polishing apparatus 10 is filled with an inert gas. In addition, the side of the wafer polishing apparatus 10 is provided with a door for the storage section of the inert gas supply means, and an operator can open the work when replacing the inert gas cylinder or during maintenance of the inert gas supply apparatus. Is configured to do.

  FIG. 2 is a plan sectional view showing a first embodiment of the wafer surface oxidation reforming preventing apparatus according to the present invention.

  As shown in FIG. 2, the wafer polishing apparatus 10 includes a wafer storage unit 20, a transfer unit 14, polishing units 16, 16, 16, a cleaning / drying unit 18, a film thickness measuring unit 29, and an inert gas supply unit 69. Has been.

  The wafer storage unit 20 includes a product wafer storage unit 20A, a dummy wafer storage unit 20B, a first monitor wafer storage unit 20C, and a second monitor wafer storage unit 20D. Each storage unit stores a wafer stored in a cassette 24. W is stored. Two product wafer storage portions 20A are provided side by side. The first monitor wafer storage section 20C uses the lower stage of the cassette 24, and the upper stage of the same cassette 24 is the second monitor wafer storage section 20D.

  The transport means 14 includes an index robot 22, a transfer robot 30, and transport units 36A and 36B. The indexing robot 22 includes two arms that can rotate and bend, and is provided so as to be movable along the direction of arrow Y in FIG. The index robot 22 takes out a wafer W to be polished from a cassette 24 placed in each wafer storage unit, transports it to the film thickness measuring means 29 and the delivery ports 26 and 28, and also cleans the wafer W after cleaning. It is received from the cleaning / drying means 18 and stored in the cassette 24. The transfer robot 30 includes a load arm 30A and an unload arm 30B that can be bent and swiveled, and is provided so as to be movable along the arrow X direction in FIG. Here, the loading arm 30A is used for transporting the wafer W before polishing, receives the unpolished wafer W from the delivery ports 26 and 28 with a pad (not shown) provided at the tip thereof, and transports units 36A and 36B. Transport to. On the other hand, the unloading arm 30B is used for transporting the polished wafer W, receives the polished wafer W from the transport units 36A and 36B with a pad (not shown) provided at the tip, and receives the cleaning / drying means 18 or Transport to unload cassette 32. The transport units 36A and 36B are both movably provided along the arrow Y direction in FIG. 2, and move between the receiving positions SA 1 and SB and the delivery positions TA 1 and TB, respectively. The wafer W to be polished is received from the loading arm 30A of the transfer robot 30 at the receiving positions SA 1 and SB, moved to the transfer positions TA 1 and TB 2 and transferred to the polishing heads 38A and 38B. Further, the polished wafer W is received at the delivery positions TA 1 and TB 2, moved to the reception positions SA 2 and SB 1, and delivered to the unloading arm 30 B of the transfer robot 30. Each of the transfer units 36A and 36B has two separate cradles, and these two cradles are used separately for the wafer W before polishing and for the wafer W after polishing. An unload cassette 32 is provided next to the cleaning / drying means 18 and is used when temporarily storing the polished wafer W. For example, the polished wafer W is transferred to the transfer robot 30 and temporarily stored while the operation of the cleaning / drying means 18 is stopped.

  The polishing means 16, 16, and 16 polish the wafer W, and as shown in FIG. 2, polishing surface plates 34A, 34B, and 34C, polishing heads 38A and 38B, slurry supply nozzles 37A, 37B, and 37C, and a carrier cleaning unit 40A and 40B are provided. The polishing surface plates 34A, 34B, 34C are formed in a disk shape, and three of them are arranged in parallel. A polishing pad (not shown) is affixed to the upper surface of each polishing platen 34A, 34B, 34C, and slurry is supplied from the slurry supply nozzles 37A, 37B, 37C onto the polishing pad. Further, each polishing platen 34A, 34B, 34C is driven and rotated by a motor (not shown), and the wafer W is pressed against the rotating polishing platen 34A, 34B, 34C, whereby the wafer W is polished.

  Here, of the three polishing surface plates 34A, 34B, 34C, the left and right polishing surface plates 34A, 34B are used for polishing the first polishing target film, and the central polishing surface plate 34C is the second polishing target film 34C. Used for polishing. In both types of polishing, the type of slurry to be supplied, the rotation speed of the polishing head and the rotation speed of the polishing surface plate, the pressing force of the polishing head, the material of the polishing pad, and the like are changed. Dressing devices 35A, 35B, and 35C are provided in the vicinity of the polishing surface plates 34A, 34B, and 34C, respectively. The dressing devices 35A, 35B, and 35C have a pivotable arm, and dress the polishing pads on the polishing surface plates 34A, 34B, and 34C with a dresser provided at the tip of the arm. Two polishing heads, 38A and 38B, are provided, each being movably provided along the direction of arrow X in FIG.

  The polishing head 38A presses the held wafer W against the polishing pad on the polishing surface plate 34A, and supplies the slurry onto the polishing pad while rotating the polishing surface plate 34A and the polishing head 38A, respectively. Is polished. The polishing head 38B on the other side is similarly configured.

  As shown in FIG. 2, two carrier cleaning units 40A and 40B are installed between the polishing surface plates 34A, 34B and 34C, and are arranged at predetermined delivery positions TA 1 and TB 2 of the transport units 36A and 36B, respectively. Has been. The carrier cleaning units 40A and 40B clean the carriers of the polishing heads 38A and 38B after completion of polishing.

  The cleaning / drying unit 18 cleans the polished wafer W. The cleaning / drying means 18 includes a cleaning device 68A and a drying device 68B. The cleaning device 68A has three cleaning tanks, and is arranged in the order of rough cleaning, precision cleaning, and rinsing. In the rough cleaning section, an alkaline solution is poured onto the wafer W, and the surface of the wafer W is cleaned with a double side brush. In the precision cleaning unit, an acidic chemical solution is poured onto the wafer W, and the surface of the wafer W is cleaned with a double side brush. In the rinsing section, precision cleaning with a pen brush is performed while supplying ultrasonic water. The wafer W polished by the polishing means 16, 16, 16 is transferred to the cleaning / drying means 18 by the transfer robot 30, and after being roughly cleaned, precision cleaned and rinsed by the cleaning device 68 </ b> A of the cleaning / drying means 18. And dried by the drying device 68B. The dried wafer W is taken out from the drying device 68B by the index robot 22 of the transport means 14, and after being measured for the film thickness by the film thickness measuring means 29 as necessary, it is set in the wafer storage unit 20. The cassette 24 is stored in a predetermined position.

  The film thickness measuring means 29 has a centering mechanism for the wafer W and a film thickness measuring machine. In the film thickness measuring device, when the film to be polished is an oxide film, an optical interference type film thickness measuring machine or the like is used. Used.

  Further, the inert gas supply means 69 of the wafer surface oxidation reforming prevention apparatus according to the present invention is filled with a rare gas such as helium, argon, or neon, or an inert gas having a low reactivity such as nitrogen, carbon dioxide, or the like. An inert gas cylinder 70, a valve 72 for controlling supply and stop of supply of the inert gas, a vaporizer 74 for vaporizing the inert gas stored as a liquid, and a supply pressure of the inert gas to atmospheric pressure And a governor 76 for adjusting the pressure to a little higher than the atmospheric pressure.

  During the transfer process or cleaning process of the wafer W, the valve 72 is opened, the inert gas or its liquid flows out from the inert gas cylinder 70 to the vaporizer 74, and the inert gas vaporized by the vaporizer 74 is discharged. After the pressure is set to a predetermined value by the governor 76, it flows out into the transfer cleaning chamber 82 (a storage chamber including a transfer chamber and a cleaning chamber that cuts off the wafer W from the outside air) through the gallery. In this way, since the inside of the transfer cleaning chamber 82 is set to substantially the same pressure as the atmospheric pressure or a pressure slightly higher than the outside world, air containing oxygen does not flow in from the outside. Can be filled with an inert gas. In the transfer cleaning chamber 82 shown in FIG. 2, the wafer W existing up to the transfer process, the cleaning process, the inspection process, and the storage process can be shielded from outside air.

  Further, the transport cleaning chamber 82 is provided with a damper 80 serving as a gas discharge port in the transport cleaning chamber 82. When the pressure in the transport cleaning chamber 82 becomes higher than the atmospheric pressure of the outside, the damper 80 can cause a gas having a flow rate corresponding to the pressure difference to flow out of the transport cleaning chamber 82. Further, instead of providing the damper 80, a blower 78 may be provided to discharge the gas in the transport cleaning chamber 82 to the outside.

  In the above description, the example in which the inert gas flows out at a constant pressure by the action of the governor 76 has been described. However, the present invention is not limited to this, and the pressure in the transport cleaning chamber is measured with a pressure gauge. However, the object of the present invention can be achieved even if the flow rate of the inert gas and the discharge pressure are adjusted based on the measured pressure.

  The transfer cleaning chamber 82 is provided with openings such as doors for loading and unloading the wafer W and maintenance doors such as the polishing head 38A and the dressing apparatus 35A. Is provided with a packing, and employs a structure that substantially blocks the outside atmosphere.

  In addition, since it is mainly the wafer W after polishing that causes oxidation and modification of the wafer surface, the storage chamber that blocks the wafer W from the outside air has a transfer process section and rough cleaning after processing. You may make it provide independently in a process part, a precision cleaning process part, a rinse process part, an inspection process part, or a wafer storage part after processing, respectively. In addition, a wafer cleaning device provided with a transport device 14, a cleaning device 68A, a drying device 68B, a film thickness measuring device 29 (inspection process), etc. is provided in a housing separate from the polishing device 16, and the storage chamber of the cleaning device is provided. It is possible to achieve the object of the present invention by carrying out the transfer process, the cleaning process, the rinsing process, the drying process, the inspection process, the storing process, etc. of the wafer W in the state filled with the inert gas. .

  FIG. 3 shows another embodiment of the containment chamber in the wafer surface oxidation reforming prevention apparatus according to the present invention.

  FIG. 2 is a cross-sectional view of the module storage chamber provided in the polishing means 16, the cleaning device 68 </ b> A, and the drying device 68 </ b> B in the wafer polishing apparatus 10 as viewed from the side of the polishing apparatus 10. The inert gas flows out from the upper part of the wafer polishing apparatus 10 and from the upper parts of the module storage chambers such as the polishing means 16, the cleaning apparatus 68A, and the drying apparatus 68B. It is exhausted from the bottom of the module storage room.

  In the example shown in FIG. 2, the entire wafer polishing apparatus 10 is shown as an example in which one storage chamber is used. However, as shown in FIG. 3, a cleaning process unit, a drying process unit, and a rinse as necessary. It is possible to achieve the object of the present invention by providing a module storage chamber for shutting off the wafer W from the outside air in the process section or the inspection process section and filling it with an inert gas.

  FIG. 4 is a block diagram of a signal processing system of the polishing apparatus.

  As shown in FIG. 4, the signal processing system of the wafer polishing apparatus 10 includes a storage unit 11, a detection unit 12, a polishing performance index calculation unit 13, a polishing status determination unit 15, a polishing condition setting unit 17, a first control unit 19, and the like. Various control blocks are provided. The storage means 11 stores the film thickness data of the wafer W measured by the film thickness measurement means 29, the detection means 12 detects various troubles occurring in the wafer polishing apparatus 10, and the polishing performance index calculation unit 13 determines the film It is possible to calculate polishing performance indicators such as polishing uniformity, polishing rate, and polishing shape from thickness data and processing time required for polishing. In the polishing status determination unit 15, whether to polish the product wafer W or monitor polishing with the monitor wafer from the polishing performance index such as the polishing uniformity, polishing rate, and polishing shape obtained by the polishing performance index calculation unit 13. It has a means to judge. The polishing condition setting unit 17 sets polishing conditions and polishing shape control parameters from polishing performance indexes such as polishing uniformity, polishing rate, and polishing shape obtained by the polishing performance index calculation unit 13. The first control means 19 is a controller that controls the movement of the apparatus in response to the determination signals and setting signals in the above-described units, and the display means 19A is a display that displays polishing performance indicators, polishing conditions, and the like.

  The wafer polishing apparatus 10 configured as described above processes the wafer W as follows.

  First, in the polishing process, the inside of the transport cleaning chamber 82 is filled with an inert gas. In the transfer cleaning chamber 82, the ratio of the inert gas gradually increases, and the amount of oxygen contained in the transfer cleaning chamber 82 relatively decreases. By filling the inside of the transfer cleaning chamber 82 with an inert gas, it is possible to improve the oxidation and modification of the wafer surface in the transfer process, the cleaning process, the drying process, the inspection process and the like after the CMP process. Become.

  When the transfer cleaning chamber 82 is filled with an inert gas, the CMP processing of the wafer W is started. The wafers W stored in the cassette 24 are taken out by the index robot 22 and transferred to the film thickness measuring means 29. The film thickness measuring means 29 performs centering and film thickness measurement as necessary. The centered wafer W is taken out by the index robot 22 and placed on the delivery port 26 or 28. Next, it is taken out from the delivery port 26 or 28 by the loading arm 30A of the transfer robot 30, and is transferred to the transfer unit 36A. In the transfer unit 36A, the loading cradle is waiting in advance at a predetermined receiving position SA, and the wafer W is delivered from the loading arm 30A to the loading cradle positioned at the receiving position SA. The loading cradle to which the wafer W has been delivered moves forward to a predetermined delivery position TA. Above the delivery position TA, the polishing head 38A is waiting in advance, and the wafer W is delivered to the polishing head 38A from the loading cradle.

  The polishing head 38A that has received the wafer W sucks and holds the wafer W with a carrier, and moves to a predetermined polishing position PA. Then, the suction is released at that position, and the wafer W is placed on the polishing pad to polish the wafer W. The polishing is performed by rotating both the polishing platen 34A and the polishing head 38A while pressing the wafer W against the polishing pad with a carrier, and supplying slurry from the slurry supply nozzle 37A onto the rotating polishing pad. Polish the membrane.

  The wafer W after the polishing is again held by the carrier and collected from the polishing surface plate 34A. Thereafter, when polishing the second polishing target film, the polishing head 38A moves to the polishing position PC on the central polishing surface plate 34C as it is. Then, the second polishing target film is polished by changing the polishing characteristics on the center polishing platen 34C. On the other hand, when the polishing is completed with only the first polishing target film, the polishing head 38A moves to the predetermined delivery position TA. Then, the wafer W is delivered to the unload receiving base of the transfer unit 36A that is positioned in advance at the delivery position TA.

  Even when the second polishing target film is polished by the central polishing platen 34C, the polishing head 38A moves from the polishing position PC to the delivery position TA after the polishing is completed, and the wafer is transferred to the unloading cradle. Deliver W.

  The unload receiving table of the transfer unit 36A to which the polished wafer W is transferred at the transfer position TA 1 moves backward to the predetermined receiving position SA. Then, the wafer W is taken out from the unloading pedestal located at the receiving position SA by the unloading arm 30B of the transfer robot 30 and transferred to the cleaning / drying means 18.

  The wafer W transferred to the cleaning / drying means 18 is roughly cleaned, precision cleaned and rinsed by the cleaning device 68A, and then dried by the drying device 68B. Then, the wafer W dried by the drying device 68B is taken out from the drying device 68B by the index robot 22 of the transporting unit 14, and transported to the film thickness measuring unit 29 as necessary, and after the film thickness is measured, the wafer W is measured again. It is stored in a predetermined position of the cassette 24 set in the wafer storage unit 20 by the index robot 22. The polishing of one wafer W is completed in an inert gas atmosphere through a series of steps.

  FIG. 5 is a plan sectional view showing a second embodiment of the apparatus for preventing oxidation modification of a wafer surface according to the present invention.

  As shown in the figure, the wafer polishing apparatus 10A includes a wafer polishing means 16, an unload cassette 32 (which may have a function of a wafer storage chamber 90 described later), and each cleaning module of the cleaning apparatus 68A. And a drying device 68B, and a wafer storage chamber 90 is provided in or near each of them. The wafer storage chamber 90 is filled with a poorly reactive liquid such as pure water or a poorly reactive gas such as an inert gas based on instructions from the first control means 19 or the second control means 21 described later. It is possible.

  FIG. 6 shows a block diagram of a signal processing system of the polishing apparatus.

  The block diagram shown in the figure is a diagram showing an embodiment in which the second control means 21 independent of the block diagram shown in FIG. 4 is provided. Therefore, the description of the block having the same function as in FIG. 4 is omitted.

  As in the embodiment shown in FIG. 4, the detection means 12 can detect various troubles in the polishing apparatus 10 </ b> A and troubles in the first control means 19. The detected trouble information is transmitted from the detection means 12 to the second control means 21. When it is determined that the trouble information detected by the detection means 12 is a trouble that prevents normal polishing from being continued any more and is a serious trouble that cannot be avoided by the first control means 19 In this case, the second control unit 21 outputs switching information indicating that the control of the polishing apparatus 10A is transferred from the first control unit 19 to the second control unit 21 to the first control unit 19 and the switching unit. A specific example of the trouble that occurs in the polishing apparatus 10A will be described later.

  The first control means 19 that has received the switching information interrupts the control of the wafer polishing apparatus 10A. The switching means that has received the switching information switches the control of the transfer means 14, the polishing means 16, the cleaning / drying means 18, the product wafer storage unit 20 </ b> A from the conventional first control means 19 to the second control means 21. Process. By this control switching process, the second control unit 21 can control the transfer unit 14, the polishing unit 16, the cleaning / drying unit 18, the product wafer storage unit 20A, and the like.

  When the overall control of the polishing apparatus 10A is transferred from the first control means 19 to the second control means 21 in response to the occurrence of a trouble in the polishing apparatus 10A, the second control means 21 A “wafer saving program” is executed in which the wafer W being polished or the wafer W that has been polished is loaded into the wafer storage chamber 90 using the polishing head 38A or the like. Further, instead of carrying the wafer W into the wafer storage chamber 90, the wafer W may be carried into the cassette 24 via the transfer unit 36A, the transfer robot 30, the index robot 22, or the like.

  In addition, the wafer loading means such as the transfer robot 30, the polishing head 38, the transfer units 36A and 36B, and the indexing robot 22 may be in trouble with the wafer polishing apparatus 10A based on the instruction of the second control means 21 or the detection means 12. When the occurrence is detected, it is possible to retract and store the wafer during processing, after processing, during cleaning, after cleaning or during movement.

  When the detecting means 12 detects that a trouble has occurred in the wafer polishing apparatus 10A, the second control means 21 selects a wafer during processing, after processing, during cleaning, after cleaning or during movement based on the trouble information. In order to evacuate, an instruction to carry the wafer W into the wafer storage chamber 90 can be output to the wafer carrying means such as the transfer robot 30, the polishing head 38, the transfer units 36 </ b> A and 36 </ b> B, and the index robot 22. Yes.

  Further, instead of the detection means 12 directly detecting various troubles in the wafer polishing apparatus 10A, the polishing means 16, the cleaning / drying means 18, the wafer storage units 20A, 20B, 20C, the transfer robot 30, and the polishing heads 38A, 38B. The wafer carry-in means such as the transfer units 36A and 36B and the index robot 22 detect troubles and errors in the respective modules and output the information directly to the first control means 19 or the second control means 21. Also, the object of the present invention can be achieved.

  The case where the wafer W is retracted into the wafer storage chamber 90 after processing is a case where a trouble has occurred in the wafer polishing apparatus 10A, and the detection means 12 shown in FIG. When it is detected that a defect has occurred in the wafer W in terms of quality, when a defect has occurred in the function of the polishing pad, etc., or when it has been detected that a defect has occurred in the polishing surface plate 34A, etc. When it is detected that a failure has occurred in 35A, etc., when it has been detected that a failure has occurred in the transport unit, or when it has been detected that a failure has occurred in the slurry or cleaning water to be supplied, a failure has occurred in the transfer robot 30 If it is detected that a failure has occurred in the index robot 22, a failure has occurred in another process. And the like when it is detected that was.

  Further, when the wafer W is retracted into the wafer storage chamber 90 during cleaning, when the detecting means 12 detects that a defect has occurred in the quality of the wafer W during cleaning, the cleaning brush itself or the driving of the cleaning brush is driven. When it is detected that a failure has occurred in the transfer robot 30, when it is detected that a failure such as a shortage or clogging has occurred in the supplied cleaning liquid or cleaning water, or when a failure has occurred in the transfer robot 30, the index robot This is the case where it is detected that a defect has occurred in 22 or when it is detected that a defect has been detected in another process.

  Further, when the wafer W is retracted to the wafer storage chamber 90 during the movement, when the detecting means 12 detects that a defect such as cracking and dropping occurs in the wafer W during the movement, a defect occurs in the transfer device. Such as when a failure occurs in the transfer robot 30, when a failure occurs in the index robot 22, or when a failure is detected in another process.

  In the above example, the signal processing system block diagram shown in FIG. 6 has been described with reference to the embodiment in which the detecting means 12 detects a trouble in the polishing apparatus 10A. However, the present invention is limited to the embodiment shown in FIG. However, the object of the present invention can be achieved even with the wafer polishing apparatus 10 using the signal processing system block diagram shown in FIG. In that case, the second control means 21 does not control the wafer polishing apparatus 10 </ b> A in place of the first control means 19, but if a trouble occurs, a normal polishing process in the first control means 19 is performed. Instead of the program, a “wafer saving program” is started when trouble occurs, and an instruction to save the wafer during processing, after processing, during cleaning, after cleaning, or during movement to the wafer storage chamber 90 or the cassette 24 is output. You may do it.

  FIGS. 7A and 7B show the flow of the wafer W when any defect is detected in the wafer polishing apparatus 10A after polishing.

  When the wafer W is processed as shown in FIG. 7A, first, the wafer W existing on the transfer unit 36A is sucked and held by the carrier provided in the polishing head 38A, and the wafer polishing means 16 is used. It moves onto the provided polishing surface plate 34A and polishing pad 34a. Next, the suction is released at that position, and the wafer W is placed on the polishing pad 34a to polish the wafer W. Polishing is performed by rotating both the polishing surface plate 34A and the polishing head 38A while pressing the wafer W against the polishing pad 34a with a predetermined pressing force by a carrier provided on the polishing head 38A, and on the rotating polishing pad 34a. The slurry is supplied from the slurry supply nozzle 37A to polish the first polishing target film and the second polishing target film.

  In a normal polishing process, the polished wafer W is again attracted and held by the carrier provided in the polishing head 38A and recovered from the polishing surface plate 34A, for example, a polishing constant for polishing the second polishing target film. Transfer to the board 34C or transfer onto the transport unit 36A. However, if some trouble occurs in the wafer polishing apparatus 10A during or after polishing, and when it becomes impossible to continue cleaning or inspection of the wafer W, the wafer W is provided in the polishing head 38A. The wafer is sucked and held by the carrier and collected from the polishing surface plate 34A and stored in the wafer storage chamber 90.

  As shown in FIG. 7B, the inside of the wafer storage chamber 90 functions as an inert substance filling means 88 with a liquid or inert gas with poor reactivity such as pure water or nitrogen gas, or a gas with a humidity of 90% or more. Therefore, by saving the processed wafer W in the wafer storage chamber 90, it becomes possible to prevent oxidation or modification of the surface of the wafer W when trouble occurs in the wafer polishing apparatus 10A. ing. Since the slurry adheres to the wafer W during polishing or just after the polishing, pure water may be flowed into the wafer storage chamber 90 to prevent chemical polishing from progressing by the slurry. The liquid filled in the wafer storage chamber 90 does not contain different kinds of metals and the like, and is made of ultrapure water having dissolved oxygen of 1 ppm or less or ultrapure water having a specific resistance of 16 MΩ or more, thereby oxidizing the wafer surface. And the effect of preventing modification. In addition, since ultrapure water with extremely low dissolved oxygen and ultrapure water with extremely high specific resistance are very expensive, ultrapure water with dissolved oxygen of 0.1 ppm or more and 1 ppm or less, or specific resistance of 16 MΩ or more. Also, ultrapure water of 30 MΩ or less may be used.

  When the inert fluid filling means 88 fills the wafer storage chamber 90 with the inert fluid, the inert fluid is supplied to the wafer storage chamber 90 through the valve 86 from the tank 84 in which the inert fluid is stored. .

  Further, when the inert gas filling means 88 is used to fill the wafer storage chamber 90 with an inert gas, the inert gas cylinder 70 storing the inert gas is passed through the valve 72, the vaporizer 74, the governor 76, and the like. Then, an inert fluid is supplied to the wafer storage chamber 90.

  In the above example, the wafer W is stored in the wafer storage chamber 90 provided in the wafer polishing means 16 (polishing module). However, the wafer W is the transfer robot 30 (load / unload robot). If the wafer W is in the processing range of the transfer robot 30, the first control means 19 or the second control means 21 is configured to transfer the wafer storage chamber 90 ( It may be controlled to store the wafer W in the robot wafer storage chamber.

  Similarly, when the detection means 12 detects that the wafer W is being cleaned by each cleaning module of the cleaning device 68A, or after the cleaning, some trouble has occurred in the wafer polishing device 10A, and thereafter the wafer W When the cleaning, drying, transport or inspection cannot be continued, the first control means 19 or the second control means 21 transfers the wafer W to the wafer storage chamber 90 provided in each cleaning module. You may make it store.

  Further, when the detection means 12 detects that a defect has occurred in the wafer polishing apparatus 10A while the wafer W is being dried by the drying apparatus 68B (wafer drying / cleaning module) or after drying, the drying of the wafer W is performed thereafter. When it is determined that the inspection or transfer cannot be continued, the first control unit 19 or the second control unit 21 stores the wafer W in the wafer storage chamber 90 provided in the drying module. You may do it.

  Further, a lid that can be opened and closed is provided on the transfer unit (wafer transfer cup) 36A or 36B like the wafer storage chamber 90, and the detection unit 12 is in a state where the wafer W is placed on the transfer unit 36A or 36B. If it is detected that some trouble has occurred in the wafer polishing apparatus 10A, and the wafer W can no longer be transferred, dried or inspected, the first control means 19 or the second control The means 21 outputs an instruction to close the lid provided in the transport unit 36A or 36B, and the inside of the storage chamber is filled with a gas or fluid with poor reactivity such as inert gas or pure water. Good.

  When some trouble that cannot be dealt with occurs in the wafer polishing apparatus 10A or the like, a warning lamp is turned on or a warning signal is generated to entrust the operator to solve the trouble. Then, when the operator of the wafer polishing apparatus 10A etc. performs the work to solve the trouble and the work is finished, the operator operates the operation buttons and touch panel provided on the wafer polishing apparatus 10A etc. to cancel the error. Instruct to resume the polishing process.

  Then, the 1st control means 19 or the 2nd control means 21 performs the process which carries out the wafer W stored in the wafer storage chamber 90 or the cassette 24 after the process in which the last process was complete | finished. When the second control unit is in charge of controlling the wafer polishing apparatus 10A and returns to normal processing, the switching unit and the first control unit are instructed to transfer control. Then, the control of the wafer polishing apparatus 10A is switched to the first control unit, and the processing and cleaning of the wafer W are continuously performed based on the instruction of the first control unit 19 thereafter.

External perspective view of wafer surface oxidation reforming prevention apparatus according to the present invention 1 is an overall plan sectional view showing a first embodiment of a wafer surface oxidation reforming prevention apparatus according to the present invention; The figure which shows other embodiment of the storage chamber of the oxidation reforming prevention apparatus of the wafer surface which concerns on this invention Signal processing block diagram of polishing equipment Plan sectional drawing which shows 2nd Embodiment of the oxidation reforming prevention apparatus of the wafer surface which concerns on this invention Signal processing block diagram of polishing equipment Diagram showing wafer flow when a defect is detected after polishing

Explanation of symbols

W ... Wafer, 10, 10A ... Wafer polishing apparatus, 11 ... Storage means, 12 ... Detection means, 13 ... Polishing performance index calculation section, 14 ... Conveyance means, 15 ... Polishing condition judgment section, 16 ... Polishing means, 17 ... Polishing Condition setting unit 18 ... Cleaning / drying unit 19 ... First control unit 19A ... Display unit 20A ... Product wafer storage unit 20B ... Dummy wafer storage unit 20C ... First monitor wafer storage unit 20D ... First 2 monitor wafer storage unit, 21 ... second control means, 22 ... index robot, 26, 28 ... delivery port, 29 ... film thickness measuring means, 30 ... transfer robot, 32 ... unload cassette, 34A, 34B, 34C ... Polishing surface plate, 36A, 36B ... Conveyance unit, 38A, 38B ... Polishing head, 68A ... Cleaning device, 68B ... Drying device, 69 ... Inert gas Supply means, 70 ... inert gas cylinder, 72 ... valve, 74 ... vaporizer, 76 ... governor, 78 ... blower, 80 ... damper, 82 ... transport cleaning chamber, 84 ... tank, 86 ... valve, 88 ... filled with inert substance Means, 90 ... wafer storage chamber

Claims (8)

At least polishing means for CMP polishing the transferred wafer, cleaning means for cleaning the transferred wafer, drying means for drying the transferred wafer, polishing means for the wafer, cleaning means, and drying means In the apparatus for preventing oxidation or modification of the surface of the wafer staying in the wafer polishing apparatus equipped with a conveying means that sequentially conveys the trouble due to the trouble that has occurred,
Detecting means for detecting occurrence of the trouble;
A wafer storage chamber filled with an inert liquid;
When the occurrence of the trouble is detected by the detection means, wafer retracting means for carrying the wafer into the wafer storage chamber,
An apparatus for preventing oxidation modification of a wafer surface, comprising:   2. The wafer retracting unit according to claim 1, wherein when the occurrence of the trouble is detected by the detecting unit, the wafer storing unit stores a wafer being polished or polished by the polishing unit in the wafer storage chamber. Oxidation reforming prevention device for wafer surface.   3. The wafer retracting unit according to claim 1, wherein, when the occurrence of the trouble is detected by the detecting unit, the wafer being cleaned by the cleaning unit is stored in the wafer storage chamber. The apparatus for preventing oxidation modification of the wafer surface as described.   4. The wafer retracting unit according to claim 1, wherein when the occurrence of the trouble is detected by the detecting unit, the wafer storing unit stores a wafer being dried or dried by the drying unit. The apparatus for preventing oxidation modification of a wafer surface according to any one of the above.   5. The wafer retracting unit stores the wafer being transferred by the wafer transfer unit in the wafer storage chamber when the occurrence of the trouble is detected by the detecting unit. 6. The apparatus for preventing oxidation of a wafer surface as described in 1.   6. The wafer surface oxidation reforming prevention apparatus according to claim 1, wherein the inert liquid flows in the wafer storage chamber.   7. The apparatus for preventing oxidation of a wafer surface according to claim 1, wherein the inert liquid is pure water. At least polishing means for CMP polishing the transferred wafer, cleaning means for cleaning the transferred wafer, drying means for drying the transferred wafer, polishing means for the wafer, cleaning means, and drying means In a method for preventing oxidation or modification of the surface of a wafer that has accumulated due to a trouble that has occurred in a wafer polishing apparatus equipped with a conveying means that sequentially conveys,
A trouble detection step of detecting the occurrence of the trouble;
When the occurrence of the trouble is detected, a wafer retracting process for storing the wafer in a wafer storage chamber filled with an inert liquid,
A method for preventing oxidation modification of a wafer surface, comprising:

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