JPWO2010113941A1 - Method for cooling object to be processed and object processing apparatus - Google Patents

Abstract

A cooling method for cooling an object to be processed is disclosed. In this cooling method, the object to be processed is placed on the stage, and a cooling gas is blown to a region in the vicinity of the center including the object center placed on the stage to cool the object to be processed. And a step of performing.

Description

  The present invention relates to a cooling method for cooling a target object and a target object processing apparatus capable of executing this cooling method.

  In a manufacturing process of a semiconductor device or the like, a high-temperature process such as a film formation process or a heat treatment is performed on a semiconductor wafer (hereinafter referred to as a wafer) that is a target object. In order to unload a wafer processed at a high temperature from the processing apparatus, the temperature of the wafer must be cooled to a safe temperature.

  Conventionally, wafer cooling is performed in a load lock chamber that performs pressure conversion between a reduced pressure state and an atmospheric state, and the wafer is naturally cooled when returning from the reduced pressure state to the atmospheric pressure state (for example, Japanese Patent Laid-Open No. 2001-2001). 319885).

  However, when the wafer is naturally cooled while returning from the reduced pressure state to the atmospheric pressure state, the wafer cools from the edge, and thus a temperature difference occurs between the edge and the center.

  Recently, the diameter of the wafer is increasing, and the temperature difference between the edge and the center tends to increase. Further, the miniaturization of elements is also progressing, and there is a tendency that the demand for suppressing the deformation of the wafer, such as the warping of the wafer due to the temperature difference between the edge and the center, becomes severe.

  Therefore, at present, expansion of the temperature difference between the edge and the center is suppressed by slowly returning the pressure from the reduced pressure state to the atmospheric pressure state.

  According to such a method, the expansion of the temperature difference between the edge and the center can be suppressed, and the warping of the wafer and the occurrence of cracks can be suppressed.

  However, there is a situation in which the throughput tends to decrease because the pressure is slowly restored from the reduced pressure state to the atmospheric pressure state.

  The present invention is capable of executing a cooling method of an object to be processed capable of improving the throughput while suppressing the occurrence of wafer warping and cracking exceeding an allowable range, and the cooling method. An object processing apparatus is provided.

  A cooling method for an object to be processed according to a first aspect of the present invention is a cooling method for cooling an object to be processed, the step of placing the object to be processed in a heated state on a stage, And a step of cooling the object to be processed by spraying a cooling gas onto a region in the vicinity of the center including the center of the object to be processed.

  In addition, an object processing apparatus according to a second aspect of the present invention is provided with a load lock chamber capable of pressure conversion between a reduced pressure state and an atmospheric pressure state, the load lock chamber, and the object to be processed is placed thereon. And a cooling gas discharge section that is provided in the load lock chamber so as to be opposed to the stage and blows a cooling gas to the object to be processed placed on the stage.

The top view which shows roughly an example of the to-be-processed object processing apparatus which can perform the cooling method of the to-be-processed object which concerns on one Embodiment of this invention Sectional drawing which shows the 1st example of a load lock chamber roughly Diagram showing temperature distribution of wafer Diagram showing the relationship between wafer position and temperature difference Diagram showing the relationship between wafer position and temperature difference Diagram showing the relationship between wafer position and temperature difference Diagram showing the relationship between wafer position and temperature difference Sectional drawing which expands and shows the shower head vicinity shown in FIG. The figure which shows the relationship between the temperature difference in the wafer surface and the diameter of the shower head The figure which shows the relationship between the temperature difference in the wafer surface and the diameter of the shower head The figure which shows the relationship between the temperature difference in the wafer surface and the diameter of the shower head Sectional drawing which shows the 2nd example of a load lock chamber roughly Sectional drawing which shows the 3rd example of a load lock chamber roughly FIG. 6 is a plan view schematically showing the shower head shown in FIG. Sectional drawing which shows the 4th example of a load lock room roughly Sectional drawing which shows the 5th example of a load lock chamber roughly Sectional drawing which shows the 5th example of a load lock chamber roughly Sectional drawing which shows the 6th example of a load lock chamber roughly Sectional drawing which shows the 6th example of a load lock chamber roughly Sectional drawing which shows the seventh example of a load lock chamber The top view which shows roughly the modification of a substrate processing apparatus

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that common parts are denoted by common reference numerals throughout the drawings.

  FIG. 1 is a plan view schematically showing an example of a target object processing apparatus capable of executing a method for cooling a target object according to an embodiment of the present invention. This example illustrates a target object processing apparatus that is used for manufacturing a semiconductor device as a target object processing apparatus and performs processing on a wafer, for example. However, the present invention is not applied only to an object processing apparatus for processing a wafer.

  As shown in FIG. 1, an object processing apparatus 1 according to an embodiment includes a processing unit 2 that performs processing on a wafer W, a loading / unloading unit 3 that loads / unloads the wafer W into / from the processing unit 2, and an apparatus 1. And a control unit 4 for controlling.

  An object processing apparatus 1 according to this example is a cluster tool type (multi-chamber type) semiconductor manufacturing apparatus.

  In this example, the processing unit 2 includes two processing chambers (PM) for processing the wafer W (processing chambers 21a and 21b). Each of these processing chambers 21a and 21b is configured so that the inside thereof can be depressurized to a predetermined degree of vacuum. For example, in the processing chambers 21a and 21b, PVD processing, for example, sputtering processing, which is processing at high vacuum (low pressure). Then, a predetermined metal or metal compound film is formed on the substrate W to be processed, for example, a semiconductor wafer. The processing chambers 21a and 21b are connected to one transfer chamber (TM) 22 via gate valves G1 and G2.

  The loading / unloading unit 3 includes a loading / unloading chamber (LM) 31. The carry-in / out chamber 31 can be adjusted to be slightly positive with respect to the atmospheric pressure or almost atmospheric pressure, for example, with respect to the external atmospheric pressure. In this example, the plane shape of the carry-in / out chamber 31 is a rectangle having a long side when viewed from the plane and a short side perpendicular to the long side. The long side of the rectangle is adjacent to the processing unit 2. In this example, the direction along the long side is called the Y direction, the direction along the short side is called the X direction, and the height direction is called the Z direction. The loading / unloading chamber 31 includes a load port (LP) to which the carrier C in which the wafer W is accommodated is attached. In this example, three substrate load ports 32 a, 32 b, and 32 c are provided along the Y direction on the long side of the loading / unloading chamber 31 facing the processing unit 2. In this example, the number of load ports is three, but the number is not limited to these, and the number is arbitrary. Each of the load ports 32a to 32c is provided with a shutter (not shown). When a wafer C storing or empty carrier C is attached to these load ports 32a to 32c, the shutter (not shown) is released. The inside of the carrier C and the inside of the carry-in / out chamber 31 are communicated with each other while preventing the entry of outside air.

  Between the processing unit 2 and the loading / unloading unit 3, a load lock chamber (LLM), in this example, two load lock chambers 51a and 51b are provided. Each of the load lock chambers 51a and 51b is configured to be able to switch the inside to a predetermined degree of vacuum and atmospheric pressure or almost atmospheric pressure. The load lock chambers 51a and 51b are connected to one side of the loading / unloading chamber 31 opposite to one side where the load ports 32a to 32c are provided via the gate valves G3 and G4, and are transferred via the gate valves G5 and G6. It is connected to two sides of the chamber 22 other than the two sides to which the processing chambers 21a and 21b are connected. The load lock chambers 51a and 51b communicate with the loading / unloading chamber 31 by opening the corresponding gate valve G3 or G4, and are disconnected from the loading / unloading chamber 31 by closing the corresponding gate valve G3 or G4. Further, the corresponding gate valve G5 or G6 is opened to communicate with the transfer chamber 22, and the corresponding gate valve G5 or G6 is closed to be shut off from the transfer chamber 22.

  A loading / unloading mechanism 35 is provided inside the loading / unloading chamber 31. The loading / unloading mechanism 35 loads / unloads the wafer W with respect to the substrate carrier C to be processed. At the same time, the wafer W is carried into and out of the load lock chambers 51a and 51b. The carry-in / out mechanism 35 has, for example, two articulated arms 36a and 36b, and is configured to be able to run on a rail 37 extending along the Y direction. Hands 38a and 38b are attached to the tips of the articulated arms 36a and 36b. The wafer W is placed on the hand 38a or 38b, and the loading / unloading of the wafer W described above is performed.

  Inside the transfer chamber 22, a transfer mechanism 24 that transfers the wafer W to and from the processing chambers 21 a and 21 b and the load lock chambers 51 a and 51 b is provided. The transport mechanism 24 is disposed substantially at the center of the transport chamber 22. The transport mechanism 24 has, for example, a plurality of transfer arms that can rotate and extend. In this example, for example, holders 25a and 25b are attached to the tips of the transfer arms 24a and 24b having two transfer arms 24a and 24b. The wafer W is held by the holder 25a or 25b, and as described above, the wafer W is transferred between the processing chambers 21a and 21b and the load lock chambers 51a and 51b.

  The processing unit 4 includes a process controller 41, a user interface 42, and a storage unit 43.

  The process controller 41 is composed of a microprocessor (computer).

  The user interface 42 includes a keyboard on which an operator inputs commands for managing the workpiece processing apparatus 1, a display that visualizes and displays the operating status of the workpiece processing apparatus 1, and the like.

  The storage unit 43 performs processing on the workpiece processing apparatus 1 according to a control program, various data, and processing conditions for realizing processing performed in the workpiece processing apparatus 1 under the control of the process controller 41. Stores recipes to be executed. The recipe is stored in a storage medium in the storage unit 43. The storage medium can be read by a computer, and can be, for example, a hard disk or a portable medium such as a CD-ROM, a DVD, or a flash memory. Moreover, you may make it transmit a recipe suitably from another apparatus via a dedicated line, for example. Arbitrary recipes are called from the storage unit 43 by an instruction from the user interface 42 and executed by the process controller 41, whereby processing on the wafer W is performed in the workpiece processing apparatus 1 under the control of the process controller 41. Is implemented.

  FIG. 2 is a cross-sectional view schematically showing a first example of the load lock chamber 51a or 51b.

  As shown in FIG. 2, in the load lock chamber 51a or 51b, a stage on which the wafer W is placed, in this example, a cooling stage, for example, a cooling stage 52 having a water cooling type cooling mechanism 52a is arranged. ing.

  The ceiling wall 53 of the load lock chamber 51a or 51b is provided with a cooling gas discharge part, in this example, a shower head 54. The shower head 54 is provided to face the cooling stage 52. The wafer W is placed on the cooling stage 52 so that the center of the wafer W coincides with the center of the shower head 54.

Cooling gas is supplied to the shower head 54 from the cooling gas supply mechanism 60 via the flow rate adjustment valve 61. Examples of the cooling gas include an inert gas such as nitrogen (N ₂ ) gas, helium (He) gas, and argon (Ar) gas, and a rare gas. A plurality of cooling gas discharge holes 54 a are formed on the surface of the shower head 54 facing the cooling stage 52.

  Furthermore, in this example, the diameter φS of the shower head 54 is set smaller than the diameter φW of the wafer W. By setting the diameter φS to be smaller than the diameter φW, the cooling gas 70 is not sprayed uniformly over the entire surface of the wafer W, but is locally sprayed in the vicinity of the center including the center of the wafer W. be able to.

  A gas exhaust port 56 is formed in the bottom wall 55 of the load lock chamber 51a or 51b. The gas exhaust port 56 is connected to an exhaust device 62 that exhausts the pressure inside the load lock chamber 51a or 51b to a predetermined degree of vacuum.

Further, a gas introduction port 57 is formed in the bottom wall 55 of the load lock chamber 51a or 51b. In this example, the gas inlet 57 is connected to the cooling gas supply mechanism 60 via a flow rate adjusting valve 63. The pressure inside the load lock chamber 51a or 51b is almost the same as the pressure inside the loading / unloading chamber 31 by introducing cooling gas from the gas inlet 57 and the shower head 54, for example, atmospheric pressure, or loading / unloading. The pressure can be increased to a pressure slightly lower than the pressure inside the chamber 31.

  FIG. 3 is a view showing the in-plane temperature distribution of the wafer W. As shown in FIG.

  As shown in FIG. 3, when the wafer W is naturally cooled, the temperature of the wafer W is lowered from the edge, and the center is most unlikely to be lowered. For this reason, in the process of lowering the temperature of the wafer W, an in-plane temperature difference that is high at the center and low at the edge occurs (line I in the figure). If the in-plane temperature difference is large, the wafer W may warp during cooling or the wafer W may crack. The allowable range of warpage of the wafer W is, for example, 0.6 mm or less for the wafer W having a diameter φW of 300 mm.

  The in-plane temperature difference occurring on the wafer W will be described in detail with reference to FIGS. 4A to 4C.

  FIG. 4A shows an in-plane temperature difference in a state where the pressure around the wafer W is 1 Pa and the wafer W is heated to about 500.degree. The diameter W of the wafer W is 300 mm, the temperature measurement points are the center (0 mm), the middle (distance ± 75 mm from the center), and the vicinity of the edge (distance ± 140 mm from the center).

  In FIG. 4A, the temperature near the edge is about 500.degree. The measurement results show that the middle temperature is about 20 ° C. higher than the temperature near the edge (= about 520 ° C.), and the center is about 25 ° C. higher (= about 525 ° C.).

  From the depressurized state shown in FIG. 4A, the atmosphere is released at once, the pressure around the wafer W is changed to the atmospheric pressure state (about 100000 Pa), and the temperature of the wafer W is cooled so as to converge to about 70 ° C. FIG. 4C shows a state cooled to about 70 ° C.

  As shown in FIG. 4C, when cooled to about 70 ° C., the in-plane temperature difference in the vicinity of the center, middle, and edge is about 6 ° C. or less (about 70 ° C. in the center and about 64 ° C. in the vicinity of the edge). Become. That is, the in-plane temperature difference is relaxed as compared to the maximum of about 25 ° C. before the start of cooling.

  However, during the cooling process, the temperature of the wafer W is lowered from the edge, so that the temperature of the center is hardly lowered. In particular, this tendency is prominent in cooling after the air is released to the atmosphere at once, that is, in natural cooling. For this reason, as shown in FIG. 4B, the in-plane temperature difference increases during the cooling process. The expansion of the in-plane temperature difference during cooling can cause, for example, warping of the wafer W exceeding 0.6 mm and generation of cracks.

  In order to suppress such warping and cracking, the pressure return from the reduced pressure state to the atmospheric pressure state is performed slowly, the rapid decrease in the edge temperature during the cooling process is suppressed, and the in-plane temperature difference is alleviated. (II line in FIG. 3 and FIG. 5). However, since the pressure return from the reduced pressure state to the atmospheric pressure state is performed slowly, the throughput is likely to decrease.

  Therefore, in one embodiment, the shower head 54 is used to blow the cooling gas 70 locally to a region near the center including the center of the wafer W. With this configuration, the temperature drop in the region near the center of the wafer W is controlled to be equal to the temperature drop in the region near the edge of the wafer W.

  The cooling gas 70 is sprayed, that is, the wafer W is cooled, for example, when the pressure is changed from the reduced pressure state to the atmospheric pressure state in the load lock chamber 51a or 51b. At this time, the cooling gas may be supplied also from the gas introduction port 57 into the load lock chamber 51a or 51b to perform pressure conversion from the reduced pressure state to the atmospheric pressure state.

  In this example, since the stage 52 has the cooling mechanism 52a for cooling the wafer W, the cooling of the wafer W is performed using the cooling gas 70 and the cooling mechanism 52a.

  As described above, according to the embodiment, the cooling gas 70 is locally blown to a region in the vicinity of the center including the center of the wafer W to forcibly increase the temperature drop in the region in the vicinity of the center of the wafer W. For this reason, the wafer W is cooled more quickly than in the case where the pressure is slowly returned from the reduced pressure state to the atmospheric pressure state and cooling is performed while suppressing the temperature of the edge of the wafer W from rapidly decreasing. Can do.

  In addition, the temperature drop in the region near the center of the wafer W is controlled to be equal to the temperature drop in the region near the edge of the wafer W. For this reason, it is possible to suppress warping of the wafer W and occurrence of cracks exceeding the allowable range.

(First example)
6 is an enlarged cross-sectional view showing the vicinity of the shower head 54 shown in FIG.

  As shown in FIG. 6, the cooling gas 70 discharged from the shower head 54 has a flow velocity distribution that is fast at the center of the wafer W and slows toward the edge of the wafer W (line III in the figure). This is because, for example, the diameter φS of the shower head 54 is set smaller than the diameter φW of the wafer W.

  Further, if the wafer W is placed on the stage 52 so that the center of the wafer W coincides with the center of the shower head 54, the flow rate of the cooling gas 70 can be maximized at the center of the wafer W. Further, the flow velocity distribution of the cooling gas 70 can be fast in a region near the center including the center of the wafer W, and can be slowed toward the edge of the wafer W from the region near the center.

  By setting such a flow velocity distribution, the center of the wafer W where the temperature is most unlikely to be lowered can be efficiently cooled, and conversely, the cooling effect is weakened toward the edge of the wafer W where the temperature is likely to be lowered. Can do. For this reason, it is possible to obtain an advantage that the temperature of the center of the wafer W is easily brought close to the temperature of the edge of the wafer W.

  Next, an example of setting the diameter φS of the shower head 54 will be described.

  As an example of the setting of the diameter φS of the shower head 54, for example, it can be set according to the in-plane temperature difference of the wafer W before the start of cooling.

  For example, when it is desired to reduce the temperature of the wafer W in the region where the in-plane temperature difference is 20 ° C. or more, the diameter φS of the shower head 54 matches the region where the in-plane temperature difference is 20 ° C. or more. It may be the size.

  FIG. 7A shows an in-plane temperature distribution when a wafer W having a diameter φW of 300 mm is heated to about 500 ° C. This in-plane temperature distribution is the same as the in-plane temperature distribution shown in FIG. 4A. As shown in FIG. 7A, the region where the in-plane temperature difference is 20 ° C. or more is a region within a distance of ± 75 mm from the center. In this case, the diameter φS of the shower head 54 is set to 150 mm. The wafer W may be placed on the stage 52 so that the center thereof coincides with the center of the shower head 54. In this case, the area in the vicinity of the center including the center of the wafer W is an area within a radius of 75 mm from the center of the wafer W.

  Of course, the region where the temperature of the wafer W is desired to be reduced is not limited to the region where the in-plane temperature difference is 20 ° C. or more, and the in-plane temperature difference may be other than 20 ° C. In the case where the wafer W is heated to about 500 ° C. and has a diameter φW = 300 mm, and the region where the temperature is to be decreased is, for example, a region where the in-plane temperature difference is 15 ° C. or more, as shown in FIG. The diameter φS of the shower head 54 may be set to 200 mm. Similarly, the wafer W may be placed on the stage 52 so that the center thereof coincides with the center of the shower head 54. In this case, the area in the vicinity of the center including the center of the wafer W is an area within a radius of 100 mm from the center of the wafer W.

  Further, in the case where the wafer W is heated to about 500 ° C. and has a diameter φW = 300 mm, and the region in which the temperature is desired to be reduced is, for example, a region where the in-plane temperature difference is 22 ° C. or more, FIG. Thus, the diameter φS of the shower head 54 may be set to 100 mm. In this case, a region in the vicinity of the center including the center of the wafer W is a region within a radius of 50 mm from the center of the wafer W.

  That is, the diameter φS of the shower head 54 may be set based on the diameter φW of the wafer W and the size of the region where the temperature is desired to be reduced. In addition, the size of the region where the temperature is desired to be lowered may be determined based on the in-plane temperature difference generated in the wafer W during heating.

  This is not limited to the wafer W having a diameter φW = 300 mm, and it can be said that the wafer W has a diameter φW = 450 mm.

(Second example)
Further, the flow velocity distribution as shown by the line III in FIG. 6 can be obtained, for example, by using a nozzle 54b instead of the shower head 54 as shown in FIG.

(Third example)
Further, for example, as shown in FIG. 9, in the case of a shower head 54, the interior of the shower head 54 may be partitioned into two or more spaces concentrically like spaces 54c and 54d. good. FIG. 10 shows a plan view of the plurality of spaces 54c and 54d shown in FIG.

  When the concentric spaces 54c and 54d are provided, for example, the flow rate of the cooling gas 70 discharged from the space 54c including the center of the shower head 54 is changed by changing the supply flow rate of the cooling gas to the space 54c. The flow rate of the cooling gas 70 discharged from the space 54d outside the space 54c can be made faster. That is, in the vicinity of the region including the center of the wafer W, in particular, by blowing the cooling gas 70 at a higher flow rate to the portion close to the center, the cooling efficiency of the region near the center including the center of the wafer W is further increased. It can also be increased.

  In order to adjust the flow rate of the cooling gas 70, a flow rate adjuster, for example, a speed controller may be provided in the cooling gas supply path, and the flow rate of the cooling gas 70 discharged using this speed controller may be adjusted.

In addition, the flow rate of the discharged cooling gas 70 is
Cooling gas flow rate = Cooling gas flow rate / Total area of cooling gas discharge hole 54a
In other words, the flow rate of the discharged cooling gas 70 can also be adjusted by adjusting the flow rate of the cooling gas 70. In this case, a flow rate regulator such as a mass flow controller may be provided in the cooling gas supply path, and the flow rate of the cooling gas may be adjusted using this mass flow controller.

When the interior of the shower head 54 is partitioned into a plurality of spaces, for example, spaces 54c and 54d, a first cooling gas having a high cooling effect is introduced into the space 54c including the center of the shower head 54, A second gas having a cooling effect lower than that of the first gas may be supplied to the space 54d outside the space 54c. An example of the first gas is helium (He) gas, and an example of the second gas is nitrogen (N ₂ ) gas.

  Further, when the first gas is helium gas and the second gas is nitrogen gas, the flow rate of the helium gas can be made faster than the flow rate of the nitrogen gas, and the center of the wafer W can be set. The cooling efficiency of the area in the vicinity of the center can be further increased.

  According to the shower head 54 shown in FIGS. 9 and 10, the cooling efficiency of the center of the wafer W can be further increased, and the cooling effect can be controlled to become weaker toward the edge of the wafer W. The advantage that can be obtained.

(Fourth example)
Further, according to the shower head 54 shown in FIGS. 9 and 10, the diameter of the shower head 54 can be increased to the same size as the diameter of the wafer W as shown in FIG. 11.

  When the diameter of the shower head 54 is increased to the same size as the diameter of the wafer W, there are three concentric circular spaces 54d, 54e, 54f, 54g outside the space 54c including the center of the shower head 54. It is preferable to form as described above. The flow rate of the cooling gas may be gradually decreased toward the outer spaces 54d, 54e, 54f, and 54g so that a flow velocity distribution is obtained toward the outer side as indicated by line III.

  As described in the third example, the flow rate of the discharged cooling gas 70 is adjusted in the cooling gas supply path by, for example, a flow rate regulator such as a speed controller or, for example, a mass flow controller. It can be realized by providing such a flow rate regulator and adjusting the flow rate or flow rate of the cooling gas using the flow rate regulator or the flow rate regulator.

A first cooling gas (for example, helium (He) gas) having a high cooling effect is introduced into the space 54c including the center of the shower head 54, the space 54c including the center, and 54d adjacent to the space 54c. In the spaces 54d to 54g outside the space 54c, or in the spaces 54e to 54g outside the space 54d, a second gas (for example, nitrogen (N ₂ )) having a cooling effect lower than that of the first gas. Gas) may be supplied.

(Fifth example)
Further, the temperature drop of the wafer W is closely related to the distance D between the shower head 54 and the wafer W. For example, when the distance D between the shower head 54 and the wafer W is close, the cooling efficiency increases, and when the distance D is far, the cooling efficiency tends to decrease. It is also possible to control the temperature drop of the wafer W by utilizing such a tendency.

  Therefore, as shown in FIGS. 12A and 12B, the mounting table 52 may be configured to be height-adjustable, and the distance D between the shower head 54 and the wafer W may be variable. .

(Sixth example)
In the case where the distance between the wafer W and the shower head 54 is variable, in the fifth example, the mounting table 52 has a structure capable of adjusting the height in the height direction. However, as shown in FIGS. 13A and 134B, the height of the shower head 54 can be adjusted in the height direction.

  Also in the sixth example, since the distance D between the wafer W and the shower head 54 is variable, the same advantages as in the fifth example can be obtained.

(Seventh example)
In the first to sixth examples, the example in which one shower head 54 or nozzle 54b is attached to the load lock chamber 51a or 51b has been described.

  However, as shown in FIG. 14, one shower head 54 or a plurality of nozzles 54b can be attached to the load lock chamber 51a or 51b to cool a plurality of wafers W at the same time. FIG. 14 shows an example in which two shower heads 54 according to the first example shown in FIG. 6 are attached to the top wall 53 as an example.

  The modification relating to the seventh example is not limited to the first example, and can be applied to any of the second to sixth examples.

(Modification of substrate processing apparatus)
In the first to seventh examples, the example in which the wafer W is cooled in the load lock chamber 51a or 51b of the substrate processing apparatus 1 has been described.

  However, as shown in FIG. 15, the wafer W is not provided with a load lock chamber 51a or 51b, but a cooling chamber (CM) 81 for cooling the wafer W is provided on the processing unit 2 side. Alternatively, it may be cooled after processing. In this case, the cooling chamber 81 employs the structure as shown in the first to seventh examples. Thereby, also in the cooling chamber 81 provided in the process part 2 side, the same advantage as the said 1st example thru | or a 7th example can be acquired.

(Heating temperature of the object to be processed in which one embodiment can be suitably implemented)
In the object to be processed, there is a case where there is a temperature called a deformation point at which the deformation suddenly progresses or sudden deformation occurs. For example, when the object to be processed is the wafer W and the material thereof is silicon, a temperature of about 450 ° C. corresponds to the deformation point. When a silicon wafer is heated from a temperature of 450 ° C. or lower to a temperature exceeding 450 ° C., the silicon wafer is suddenly deformed. On the contrary, even if it is cooled from a temperature of 450 ° C. or higher to a temperature of less than 450 ° C., abrupt deformation occurs.

  Therefore, when the object to be processed is a silicon wafer, the above-described embodiment can be suitably used for a cooling process performed after heating to a temperature of 450 ° C. or higher.

  The physical upper limit of the heating temperature is about 1410 to 1420 ° C. or lower of the melting point of silicon. Moreover, 900 degreeC can be mentioned as a practical upper limit in an actual process.

  As described above, according to one embodiment, a cooling method for an object to be processed capable of improving the throughput while suppressing the occurrence of wafer warping and cracking exceeding an allowable range, and this cooling method. The to-be-processed object processing apparatus which can be performed can be obtained.

  The present invention has been described according to the embodiment. However, the present invention is not limited to the above embodiment, and can be appropriately modified without departing from the spirit of the invention. In the embodiment of the present invention, the above-described embodiment is not the only embodiment.

  For example, in the above embodiment, the stage is the cooling mechanism 52 including the cooling mechanism 52a that cools the wafer W. However, the stage does not necessarily include the cooling mechanism 52a.

  In the above embodiment, the gas inlet 57 is provided in the load lock chamber 51a or 51b, and the cooling gas is introduced from the gas inlet 57 when the pressure is changed from the reduced pressure state to the atmospheric pressure state. An example of the atmospheric pressure state was shown.

  However, the gas introduction port 57 may not be provided, and the cooling gas may not be introduced from the gas introduction port 57 at the time of pressure conversion from the reduced pressure state to the atmospheric pressure state. In this case, the pressure conversion from the reduced pressure state to the atmospheric pressure state is performed only by introducing the cooling gas from the cooling gas discharge unit, in the above-described embodiment, the shower head 54 or the nozzle 54b.

  Further, in the above-described embodiment, the cooling until the object to be processed after heating, for example, the wafer W after heating is placed in a reduced pressure state having a high pressure of 1 Pa and returned to an atmospheric pressure state has been described. However, the above-described embodiment can be used for cooling back from 1 to 70000 Pa to the atmospheric pressure state (about 100000 Pa) even if the pressure around the heated wafer W is not 1 Pa.

  Similarly, even if it does not return to an atmospheric pressure state, it can be used for cooling to return to a pressure between 20000 Pa and atmospheric pressure, for example.

  Moreover, in the said one Embodiment, the semiconductor wafer was illustrated as a to-be-processed object, and the silicon wafer was illustrated as a semiconductor wafer. However, the above-described embodiment is not limited to a silicon wafer, but can be applied to other semiconductor wafers such as SiC, GaAs, InP, and the like.

  Furthermore, the object to be processed is not limited to a semiconductor wafer, and may be a glass substrate used for manufacturing an FPD or a solar cell. The present invention can be applied to any object to be processed as long as it is heated.

  According to the present invention, it is possible to perform a cooling method of an object to be processed capable of improving the throughput while suppressing the occurrence of wafer warping and cracking exceeding an allowable range, and to execute this cooling method. A possible object processing apparatus can be provided.

Claims (22)

A cooling method for cooling a workpiece,
Placing the object to be processed in a heated state on the stage;
Blowing a cooling gas to a region in the vicinity of the center including the center of the object to be processed placed on the stage, and cooling the object to be processed;
A method for cooling an object to be processed.   The method for cooling a target object according to claim 1, wherein the target object heated to a temperature of 450 ° C. or higher is placed on the stage and cooled.   The method for cooling an object to be processed according to claim 1, wherein an area in the vicinity of the center including the center of the object to be processed is an area within a radius of 75 mm from the center of the object to be processed.   The method for cooling an object to be processed according to claim 1, wherein a flow rate of the cooling gas is maximized at a center of the object to be processed. The cooling gas includes a first cooling gas having a high cooling effect and a second cooling gas having a lower cooling effect than the first cooling gas;
Spraying the first cooling gas onto a region in the vicinity of the center including the center of the workpiece;
The method for cooling an object to be processed according to claim 1, wherein the second cooling gas is sprayed to an area outside the area in the vicinity of the center of the object to be processed. The stage has a cooling mechanism for cooling the object to be processed;
The method for cooling an object to be processed according to claim 1, wherein the object to be processed is cooled using the cooling gas and the cooling mechanism. The stage has a cooling mechanism for cooling the object to be processed;
The method for cooling an object to be processed according to claim 4, wherein the object to be processed is cooled using the cooling gas and the cooling mechanism. The stage has a cooling mechanism for cooling the object to be processed;
The method for cooling an object to be processed according to claim 5, wherein the object to be processed is cooled using the cooling gas and the cooling mechanism. A load lock chamber capable of pressure conversion between a reduced pressure state and an atmospheric pressure state;
A stage provided in the load lock chamber and on which a workpiece is placed;
A cooling gas discharge section that is provided in the load lock chamber and is opposed to the stage, and that blows cooling gas to the object to be processed placed on the stage;
The to-be-processed object processing apparatus which comprises.   The target object processing apparatus according to claim 9, wherein the target object heated to a temperature of 450 ° C. or higher is placed on the stage and cooled.   The to-be-processed object processing apparatus of Claim 9 whose said cooling gas discharge part is a nozzle. The cooling gas discharge part is a shower head;
The diameter of the said shower head is a to-be-processed object processing apparatus of Claim 9 smaller than the diameter of the to-be-processed object.   The to-be-processed object processing apparatus of Claim 12 whose diameter of the said shower head is 150 mm or less.   The to-be-processed object processing apparatus of Claim 12 with which the inside of the said shower head is divided concentrically by the some space. The cooling gas discharge part is a shower head;
The to-be-processed object processing apparatus of Claim 9 with which the inside of the said shower head is divided concentrically by the some space. The cooling gas includes a first cooling gas having a high cooling effect and a second cooling gas having a lower cooling effect than the first cooling gas;
Of the plurality of spaces, the first cooling gas is supplied to a space including the center of the shower head,
The to-be-processed object processing apparatus of Claim 14 with which the said 2nd cooling gas is supplied to the space outside the space where the said 1st cooling gas was supplied. The cooling gas includes a first cooling gas having a high cooling effect and a second cooling gas having a lower cooling effect than the first cooling gas;
Of the plurality of spaces, the first cooling gas is supplied to a space including the center of the shower head,
The to-be-processed object processing apparatus of Claim 15 with which the said 2nd cooling gas is supplied to the space outside the space where the said 1st cooling gas was supplied.   The target object processing apparatus according to claim 9, wherein the stage further includes a cooling mechanism that cools the target object.   The target object processing apparatus according to claim 11, wherein the stage further includes a cooling mechanism that cools the target object.   The target object processing apparatus according to claim 12, wherein the stage further includes a cooling mechanism for cooling the target object.   The target object processing apparatus according to claim 14, wherein the stage further includes a cooling mechanism that cools the target object. The load lock chamber includes a loading / unloading chamber for loading / unloading the object to be processed in an atmospheric pressure state, and a transfer chamber for transferring the object to be processed between a plurality of processing chambers for processing the object to be processed in a reduced pressure state. Is a portion that performs pressure conversion between the atmospheric pressure state and the reduced pressure state,
The object processing apparatus according to claim 9, wherein the object to be processed is cooled when pressure conversion is performed from the reduced pressure state to the atmospheric pressure state.

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