JP4469006B2 - Manufacturing method of display substrate - Google Patents

Description

The present invention relates to the production how the display substrate such as a flat panel display.

  An electrostatic chuck is used as means for fixing a substrate to be processed in a substrate processing apparatus such as a semiconductor manufacturing apparatus or a flat panel display manufacturing apparatus. In such a substrate processing apparatus, the electrostatic chucking force is exerted on the electrostatic chuck and the process is performed with the substrate fixed on the electrostatic chuck, and the electrostatic chucking force is removed after the process processing is completed. Then, the substrate is detached from the electrostatic chuck. As described above, in a substrate processing apparatus having an electrostatic chuck, adsorption and separation of the substrate with respect to the electrostatic chuck are repeatedly performed.

  The adsorption surface of the electrostatic chuck with which the substrate is in direct contact is gradually contaminated by repeated contact with the substrate as compared with the original initial clean state. This tendency becomes more prominent in proportion to the increase in the production capacity of the apparatus and the increase in the number of substrates processed.

  It is known that if the contaminants adhere to the chucking surface of the electrostatic chuck, the chucking performance will decrease, and it is possible to restore the chucking force of the electrostatic chuck by cleaning the chucking surface of the electrostatic chuck. . As one means for that, it is conceivable that the electrostatic chuck is removed from the substrate processing apparatus, and the cleaning process similar to that performed in the manufacturing process of the electrostatic chuck is performed on the electrostatic chuck.

  However, it is not realistic to remove the electrostatic chuck from the completed substrate processing apparatus because it requires a huge work scale. Furthermore, in recent years, the electrostatic chuck has also become larger with the trend of increasing the size of the substrate to be processed, so that the demerit related to the work of removing the electrostatic chuck becomes larger.

  In addition, in the trend that substrate processing speed improvement and process cleaning by a substrate processing apparatus are required, it is required to unattended and automatically clean the surface of the electrostatic chuck without involving the operator. . In order to achieve this, Patent Document 1 proposes a means for preventing foreign matter adhesion by performing a special coating on the electrostatic chucking surface of the electrostatic chuck.

  FIG. 3 is a schematic configuration diagram of an electrostatic chuck according to the prior art disclosed in Patent Document 1. As shown in FIG. FIG. 3 shows the substrate of the electrostatic chuck. This electrostatic chuck has a configuration in which a substrate can be held on a substrate holding surface constituted by an insulator layer 1001 and a conductive layer 1002. In this configuration, by dispersing and laminating a plurality of conductive layers 1002 on the adsorption surface, it is possible to greatly reduce the adhesion of the formed conductive foreign matter to the substrate that is the object to be adsorbed. It is intended to suppress and prevent the force drop.

  Further, in Patent Document 2, as a maintenance means for keeping the surface state of the electrostatic chuck constant for the purpose of removing the residual charge of the electrostatic chuck, the suction surface is obtained by irradiating the electrostatic chuck with electromagnetic waves (thermal radiation). A means for increasing the temperature is disclosed.

FIG. 4 is a schematic configuration diagram of an electrostatic chuck according to the prior art disclosed in Patent Document 2. As shown in FIG. As shown in FIG. 4, the electrostatic chuck 2001 holds the workpiece (substrate) 2002 by suction. An electrostatic chuck 2001 shown in FIG. 4 has a configuration in which the electrostatic chuck 2001 is irradiated with radiation by lamps 2003 and 2004 installed at positions facing the attracting surface of the electrostatic chuck 201. If there is residual charge in the electrostatic chuck 2001, the residual charge becomes resistance when the workpiece (substrate) 2002 is detached from the electrostatic chuck 2001, and the workpiece (substrate) 2002 is quickly removed from the electrostatic chuck 2001. I can't. On the other hand, the electrostatic chuck 2001 shown in FIG. 4 can remove the residual charge of the electrostatic chuck 2001 by irradiating the electrostatic chuck 2001 with radiation from the lamps 2003 and 2004. Therefore, the workpiece (substrate) 2002 can be quickly removed from the electrostatic chuck 2001.
JP-A-11-251417 JP 2002-26115 A

  However, in the electrostatic chuck having the configuration shown in FIG. 3, it is necessary to provide an additional function such as coating in the configuration of the electrostatic chuck, which increases the cost of the apparatus. As described above, in recent years, the electrostatic chuck has been enlarged with the increasing trend of the size of the substrate to be processed, so that the cost of coating and the like has increased remarkably.

  In addition, as shown in FIG. 4, the means for irradiating the surface of the electrostatic chuck with an electromagnetic wave to raise the temperature can obtain an effect of removing the residual charge of the electrostatic chuck. The effect of removing the adhered foreign matter can hardly be expected. The reason is that the electrostatic chuck shown in FIG. 4 is not provided with a removal path for adhered foreign matter corresponding to the charge transfer path after the high temperature treatment. That is, by applying external energy to the chucking surface of the electrostatic chuck, the foreign matter adhering to the chucking surface of the electrostatic chuck can be easily removed. Remains on top. Therefore, if the application of external energy to the chucking surface of the electrostatic chuck is stopped, the foreign matter may adhere to the chucking surface of the electrostatic chuck again.

The present invention relates to a method of manufacturing a display substrate that can remove foreign matter adhering to the chucking surface of an electrostatic chuck in a short time in a manufacturing process of a display substrate such as a flat panel display. The purpose is to provide the law .

A method of manufacturing a display substrate according to the present invention that achieves the above object includes: a base material having an adsorption surface made of an insulating material; and a substrate provided inside the base material and placed on the adsorption surface An electrode for generating an electrostatic attraction force for adsorbing the formed substrate, a heating means provided inside the base material for heating the base material, and the substrate placed on the suction surface; And a vacuum evacuation unit that evacuates the space formed between the suction surface and the display substrate manufacturing apparatus. The display substrate manufacturing method includes:
A placing step of placing a dummy substrate different from the substrate on the suction surface;
After the dummy substrate is placed on the suction surface in the placing step, the inside of the space is evacuated by the vacuum evacuation means in order to bring the dummy substrate into close contact with the suction surface. Process,
A heating step of heating the substrate by the heating means in order to make it easier to remove foreign matter adhering to the suction surface after evacuating the interior of the space in the vacuum evacuation step;
A transfer step of transferring the foreign matter adhering to the suction surface from the suction surface to the dummy substrate in close contact with the suction surface after heating the base material in the heating step;
And removing the dummy substrate, to which the foreign matter has been transferred in the transfer step, from the suction surface.

  According to the present invention, in the method for manufacturing a display substrate, foreign matter adhering to the attracting surface of the electrostatic chuck can be removed in a short time with a simple method.

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

  FIG. 1A is a cross-sectional view showing a schematic configuration of an electrostatic chuck constituting a display substrate manufacturing apparatus according to an embodiment of the present invention.

  Inside the base material 10 of the electrostatic chuck 100 constituting the display substrate manufacturing apparatus, there are built-in suction electrodes 101 for exerting an electrostatic suction force on the suction surface 120 and heating means for heating the electrostatic chuck 100. A heater 102 is provided. The suction electrode 101 is electrically connected to the suction power source 150, and the built-in heater 102 is electrically connected to the built-in heater power source 160, and power is supplied from these power sources. . The suction electrode 101 and the suction power source 150 function as an electrostatic suction force generating unit that generates an electrostatic suction force for sucking a substrate placed on the suction surface of the electrostatic chuck 100. The electrostatic chuck 100 has a vacuum exhaust through-hole 111 penetrating between the suction surface 120 and the opposite surface so as to communicate with the suction surface 120. A piping of the vacuum exhaust through-hole 111 is connected to the opening on the surface opposite to the attracting surface 120 of the electrostatic chuck 100, and a vacuum pump 170 is connected to the other end of the piping. An exhaust means is configured.

  The electrostatic chuck 100 is usually used for fixing the glass substrate 200 when processing the glass substrate 200. The processing of the glass substrate 200 is performed on the surface opposite to the surface of the glass substrate 200 that contacts the attracting surface 120 of the electrostatic chuck 100. The base material 10 of the electrostatic chuck 100 is made of an insulating material, and in this example is made of sintered ceramics. However, the material and configuration of the substrate 10 of the electrostatic chuck 100 that can be applied to the present embodiment are not limited thereto, and for example, only the attracting surface 120 of the electrostatic chuck 100 may be configured of an insulating material.

  The attracting electrode 101 generates static electricity that exerts an electrostatic attracting force on the attracting surface 120 when a voltage is applied from the attracting power source 150, and is thereby placed on the attracting surface 120 of the electrostatic chuck 100. The glass substrate 200 is fixed to the suction surface 120.

  Further, since the volume resistivity of the glass substrate 200 decreases as the temperature rises, by heating the glass substrate 200, a stronger electrostatic adsorption force can be exerted at the time of electrostatic adsorption by the electrostatic chuck 100. Therefore, the built-in heater 102 is used to heat the glass substrate 200 placed on the suction surface 120 of the electrostatic chuck 100.

  Further, the vacuum exhaust through-hole 111 is a minute space formed between the suction surface 120 of the electrostatic chuck 100 and the glass substrate 200 placed thereon, for example, helium gas for enhancing the cooling effect. For example, the glass substrate 200 is vacuum-sucked on the suction surface 120 by evacuating a groove or the like for flowing the same. Such vacuum suction is usually performed in order to temporarily fix the glass substrate 200 on the suction surface 120 before performing electrostatic suction by the electrostatic chuck 100.

  The suction electrode 101, the built-in heater 102, the vacuum exhaust through-hole 111, and the vacuum pump 170 are generally provided in an electrostatic chuck. The cleaning method for the electrostatic chuck according to the present embodiment uses these configurations that are generally provided in an electrostatic chuck to remove foreign substances adhering to the chucking surface 120 of the electrostatic chuck in a simple manner and in a short time. It is to be removed with. The electrostatic chuck cleaning method according to the present embodiment is executed by, for example, a control unit (not shown) that controls the overall operation of the display substrate manufacturing apparatus and the operation of the electrostatic chuck 100.

  The flow of the electrostatic chuck cleaning method will be described with reference to the flowchart of FIG. 1B. The electrostatic chuck cleaning method is executed as a process constituting a part of the display substrate manufacturing method.

  When the electrostatic chuck 100 is repeatedly used in a substrate processing apparatus such as a semiconductor manufacturing apparatus or a flat panel display manufacturing apparatus, foreign matter generated along with the substrate processing adheres to the suction surface 120 of the electrostatic chuck 100 and the like. If foreign matter adheres to the suction surface 120, the suction force of the glass substrate 200 is reduced, and the glass substrate 200 may move during the substrate processing, causing a problem. For this reason, it is necessary to remove foreign matter adhering to the suction surface 120. When the glass substrate 200 is attracted by the electrostatic chuck 100, an attracting force confirmation sequence is performed, and the electrostatic chuck 100 is cleaned when it is detected that a predetermined attracting force is not obtained. Done.

  In step S <b> 101, the control unit executes an attracting force confirmation sequence and determines whether or not the attracting force of the electrostatic chuck 100 is a predetermined attracting force. If the predetermined suction force is not obtained, the process proceeds to step S102. On the other hand, if the predetermined attracting force is obtained in the determination in step S101, the process of FIG. 1B ends without executing the electrostatic chuck cleaning method.

  When cleaning the electrostatic chuck 100 (S101-No), first, a dummy glass substrate, which is a clean raw glass, is placed on the suction surface 120 of the electrostatic chuck 100 (S102). Then, a voltage generated by the suction power source 150 is applied to the suction electrode 101 in order to suck the placed dummy glass substrate to the suction surface 120. The dummy glass substrate is attracted to the attracting surface 120 by generating an electrostatic attracting force (S102).

  Next, the vacuum pump 170 is operated to evacuate the inside of the minute space between the suction surface 120 and the dummy glass substrate through the evacuation through-hole 111 (S103). The exhaust pressure at this time is, for example, 1 Pa or less. By evacuation, the dummy glass substrate comes into close contact with the suction surface 120.

  Next, a voltage is applied from the built-in heater power supply 160 to the built-in heater 102 with the vacuum evacuated as described above, and the substrate 10 of the electrostatic chuck 100 is heated to a predetermined temperature, for example, 120 ° C. Then, the heating state at the predetermined temperature is maintained for a predetermined time (in this example, for example, 120 minutes) (S104). Heating makes it easier to remove foreign matter adhering to the suction surface 120 from the suction surface 120.

  In step S105, the foreign matter adhering to the suction surface 120 is transferred from the suction surface 120 to a dummy glass substrate that is in close contact with the suction surface 120.

  Thereafter, the vacuum pump 170 is stopped and the vacuum state of the micro space formed between the suction surface 120 and the dummy glass substrate is returned to the atmospheric pressure state (S106), and voltage is applied from the built-in heater power supply 160. Is stopped to lower the temperature of the base material 10 of the electrostatic chuck 100 (S107). Then, the dummy glass substrate is gripped by a robot arm (not shown), gently lifted above the electrostatic chuck 100, and the dummy glass substrate is removed from the suction surface 120 of the electrostatic chuck 100 (S108). By removing the dummy glass substrate from the suction surface 120, the foreign matter transferred to the dummy glass substrate is removed from the suction surface 120, and the surface of the suction surface 120 is cleaned.

  Thus, the cleaning method for the electrostatic chuck 100 is completed.

  According to the cleaning method for the electrostatic chuck 100 of this embodiment, the substrate 10 of the electrostatic chuck 100 is heated by the built-in heater 102 so that the foreign matter adhering to the suction surface 120 of the electrostatic chuck 100 is removed. Easy to remove from. In this state, the minute space between the suction surface 120 and the glass substrate 200 is evacuated to bring the glass substrate 200 into close contact with the suction surface 120, so that the foreign matter attached to the suction surface 120 is attached to the glass substrate 200. Transcribed.

  At this time, some of the foreign matter may be evaporated from the adsorption surface 120 by evaporation in a vacuum atmosphere. The foreign matter adhering to the suction surface 120 of the electrostatic chuck 100 can be removed from the suction surface 120 by transferring it to the glass substrate 200 in this way. Therefore, since it is not necessary to disassemble and remove the electrostatic chuck 100 from the substrate processing apparatus in order to clean the attracting surface 120 of the electrostatic chuck 100, the cleaning operation of the electrostatic chuck 100 can be performed easily and in a short time. Can do.

  In the above example, the step of heating the base material 10 of the electrostatic chuck 100 (S104) is followed by the step of evacuating the inside of the minute space formed between the suction surface 120 and the glass substrate 200 (S103). Explained the case. However, the order of both is not limited to this, and the step (S104) of heating the base material 10 of the electrostatic chuck 100 is performed by vacuuming the inside of the minute space formed between the suction surface 120 and the dummy glass substrate 200. It may be performed prior to the exhausting step (S103).

  In the above-described example, in step S101, as a process constituting a part of the display substrate manufacturing method, based on the determination result of whether or not the suction force of the electrostatic chuck 100 is a predetermined suction force, The configuration in which the cleaning process of the electrostatic chuck 100 is executed has been described. However, the gist of the present invention is not limited to this example. For example, the cleaning process of the electrostatic chuck 100 is performed when the cumulative number of processed substrates exceeds a predetermined number as a reference. Also good. The cleaning process of the electrostatic chuck 100 can be performed when the display substrate manufacturing apparatus is stopped. However, the execution timing may be between normal substrate processes or a regular maintenance period of the display substrate manufacturing apparatus. It may be inside. That is, the cleaning process for the electrostatic chuck 100 according to the present embodiment can be executed at any time when the display substrate manufacturing apparatus is stopped.

  A method of generating plasma in the substrate processing apparatus and decomposing and removing foreign matter adhering to the suction surface 120 of the electrostatic chuck 100 is also conceivable. However, in this case, the decomposed and removed foreign matter scatters in the substrate processing apparatus and adheres to the inner wall or the like, so that it becomes necessary to clean the inside of the substrate processing apparatus. On the other hand, according to the cleaning method of the present embodiment, foreign matter can be transferred and removed on the glass substrate 200, so that the foreign matter is hardly scattered and the cleaning process can be performed in a clean state. Moreover, the glass substrate 200 onto which the foreign matter has been transferred can be used any number of times by washing the foreign matter. In this example, the case where the glass substrate 200 which is a raw glass is used as a member for transferring foreign matter is illustrated, but if it is a clean and smooth plate-like member having durability against the above-described temperature rise, A member made of another inexpensive material can be applied.

  Further, in the above-described cleaning process, the case where the glass substrate 200 is brought into close contact with the suction surface 120 of the electrostatic chuck 100 only by evacuation by the vacuum pump 170 has been described. In order to generate a stronger adhesion force, the glass substrate 200 may be adsorbed to the adsorption surface 120 by an electrostatic adsorption force generated by applying a voltage to the adsorption electrode 101 in addition to adsorption by vacuum evacuation.

  Although FIG. 1A shows a configuration including a bipolar adsorption electrode 101, the configuration of the electrostatic chuck 100 is not limited to this, and a configuration including a monopolar adsorption electrode may be used. .

  In addition, when the suction surface 120 of the electrostatic chuck 100 cannot be sufficiently cleaned by the above-described cleaning process, the same process as described above is performed by setting the time for maintaining the vacuum exhaust and heating state to 240 minutes. . If the cleaning is still not sufficient, the time for maintaining the evacuation and heating state is set to 720 minutes and the same process as above is performed. By repeating the cleaning process in this manner, the suction surface 120 of the electrostatic chuck 100 can be sufficiently cleaned.

  FIG. 2 is a perspective view showing a schematic configuration of a film forming apparatus for a flat panel display which is an example of a vacuum processing apparatus to which the present invention can be applied.

  In the apparatus shown in FIG. 2, a plurality of electrostatic chuck members 100 a having the same size are divided and arranged in the vertical and horizontal directions on the same plane on the electrostatic chuck arrangement base 130. The electrostatic chuck 2100 is configured by arranging a plurality of electrostatic chuck members 100 a in the same plane on the electrostatic chuck arrangement base 130. The vacuum processing apparatus includes a vacuum chamber (not shown) that houses at least the electrostatic chuck 2100.

  The electrostatic chuck 2100 shown in FIG. 2 can support a large-sized substrate by suction because the suction surface 120 is enlarged as a whole. Each electrostatic chuck member 100a has the same configuration as the electrostatic chuck shown in FIG. 1A. Moreover, all the electrostatic chuck members 100a may be the same size. However, each of the suction power source 150, the built-in heater power source 160, and the vacuum pump 170 is shared by the plurality of electrostatic chuck members 100a. Specifically, one suction power source 150 is connected to a plurality of suction electrodes (not shown) provided in each of the plurality of electrostatic chuck members 100a via a suction power supply distribution terminal 151. . Further, one built-in heater power supply 160 is connected to a plurality of built-in heaters (not shown) provided in each of the plurality of electrostatic chuck members 100a via a heater power supply distribution terminal 161. In addition, one vacuum pump 170 is connected to the plurality of vacuum exhaust through-holes 111 provided in each of the plurality of electrostatic chuck members 100a via a distribution branch manifold 171 of the vacuum exhaust pipe.

  Even in such a large-sized apparatus, the cleaning process of the suction surface 120 of the electrostatic chuck 2100 can be performed in the same process as the cleaning process described with reference to FIG. 1A. Therefore, the foreign matter adhering to the suction surface 120 of the electrostatic chuck 2100 can be removed from the suction surface 120 by transferring it to a glass substrate placed on the suction surface 120 of the electrostatic chuck 2100. The advantage of the cleaning method of the present embodiment that the electrostatic chuck 2100 does not need to be disassembled and removed from the substrate processing apparatus in order to clean the attracting surface 120 of the electrostatic chuck 2100 is the advantage of such a large-sized apparatus. This is more advantageous when cleaning the electrostatic chuck installed in the.

It is sectional drawing which shows schematic structure of the electrostatic chuck which comprises the display substrate manufacturing apparatus which concerns on embodiment of this invention. It is a flowchart explaining the flow of the manufacturing method of the display board | substrate concerning embodiment of this invention. It is a perspective view which shows schematic structure of the film-forming apparatus for flat panel displays (vacuum processing apparatus) which is an example of the vacuum processing apparatus which can apply this invention. It is a schematic block diagram of the electrostatic chuck by a prior art. It is a schematic block diagram of the other electrostatic chuck by a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Electrostatic chuck 101 Suction electrode 102 Built-in heater 111 Vacuum exhaust through-hole 200 Glass substrate

Claims (10)

A base material having an adsorption surface made of an insulating material, an electrode provided inside the base material, and generating an electrostatic adsorption force for adsorbing a substrate placed on the adsorption surface; A vacuum that is provided inside the base material and that evacuates the inside of the space formed between the heating means for heating the base material and the substrate placed on the suction surface and the suction surface. A display substrate manufacturing method in a display substrate manufacturing apparatus having an exhaust means, the manufacturing method of the display substrate,
A placing step of placing a dummy substrate different from the substrate on the suction surface;
After the dummy substrate is placed on the suction surface in the placing step, the inside of the space is evacuated by the vacuum evacuation means in order to bring the dummy substrate into close contact with the suction surface. Process,
A heating step of heating the substrate by the heating means in order to make it easier to remove foreign matter adhering to the suction surface after evacuating the interior of the space in the vacuum evacuation step;
A transfer step of transferring the foreign matter adhering to the suction surface from the suction surface to the dummy substrate in close contact with the suction surface after heating the base material in the heating step;
Removing the dummy substrate from which the foreign matter has been transferred by the transfer step from the suction surface;
A method for manufacturing a display substrate, comprising:   The method for manufacturing a display substrate according to claim 1, wherein the space is for flowing a helium gas for enhancing a cooling effect. A base material having an adsorption surface made of an insulating material, an electrode provided inside the base material, and generating an electrostatic adsorption force for adsorbing a substrate placed on the adsorption surface; A vacuum that is provided inside the base material and that evacuates the inside of the space formed between the heating means for heating the base material and the substrate placed on the suction surface and the suction surface. A display substrate manufacturing method in a display substrate manufacturing apparatus having an exhaust means, the manufacturing method of the display substrate,
A placing step of placing a dummy substrate different from the substrate on the suction surface;
After the dummy substrate is placed on the suction surface in the placing step, the base material is heated by the heating means in order to make it easy to remove foreign matters attached to the suction surface from the suction surface. Heating process;
A vacuum evacuation step of evacuating the interior of the space by the vacuum evacuation means in order to closely attach the dummy substrate to the suction surface after heating the base material in the heating step;
A transfer step of transferring foreign matter adhering to the suction surface from the suction surface to the dummy substrate in close contact with the suction surface after the inside of the space is evacuated in the vacuum evacuation step; ,
Removing the dummy substrate from which the foreign matter has been transferred by the transfer step from the suction surface;
A method for manufacturing a display substrate, comprising:   The method for manufacturing a display substrate according to claim 3, wherein the space is for flowing a helium gas for enhancing a cooling effect.   2. The method for manufacturing a display substrate according to claim 1, wherein in the heating step, the state of heating the dummy substrate is maintained for a predetermined time.   4. The method for manufacturing a display substrate according to claim 3, wherein in the heating step, the state of heating the dummy substrate is maintained for a predetermined time.   In the placing step, the dummy substrate is attracted to the attracting surface by an electrostatic attracting force generated by applying a voltage to the electrode in order to attract the placed dummy substrate to the attracting surface. The method of manufacturing a display substrate according to claim 1, further comprising:   In the placing step, the dummy substrate is attracted to the attracting surface by an electrostatic attracting force generated by applying a voltage to the electrode in order to attract the placed dummy substrate to the attracting surface. The method for manufacturing a display substrate according to claim 3, further comprising a step of:   The method for manufacturing a display substrate according to claim 1, wherein the method is performed when the cumulative number of substrates processed exceeds a predetermined reference number.   4. The method for manufacturing a display substrate according to claim 3, wherein the method is executed when the cumulative number of processed substrates exceeds a predetermined number as a reference.

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