Wafer processing apparatus

Abstract

To shorten the time required for wafer recovery in a wafer processing apparatus.SOLUTION: Each of the wafer processing apparatuses IM and IM2 includes a processing chamber 1 that performs high-temperature processing on a wafer W having a circular shape in plan view, a primary cooling chamber X that cools the wafer W taken out from the processing chamber 1, a secondary cooling chamber Y that cools the wafer W taken out from the primary cooling chamber X, and pedestals 6 and 6-1, a 6a, and a 6b disposed in the secondary cooling chamber Y. Each of the seats 6, 6-1, 6a, and 6b includes a support portion 10 that is in surface contact with a region including a peripheral edge of an imaginary circle Wp having the same size as the wafer W.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This relates to a wafer processing apparatus that stores high-temperature processed wafers in a cassette after cooling them. [Background technology]

[0002] Wafer processing equipment that handles semiconductor substrates, such as film deposition equipment and ion implantation equipment, processes wafers at high temperatures of several hundred degrees. After wafer processing, the wafers are stored in cassettes, but if the wafers are stored in the cassettes while still hot, the heat from the wafers will cause the cassette to warp. To prevent distortion of the cassette due to the heat of the wafers, the wafers are cooled to a temperature below the heat-resistant temperature of the cassette along the wafer transport path from the processing chamber to the cassette.

[0003] Patent Document 1 discloses a batch-type film formation apparatus that gradually cools wafers after high-temperature processing. The batch-type film formation apparatus transfers wafers processed in a processing chamber to a load lock chamber adjacent to the processing chamber. In the load lock chamber, primary cooling of the wafers is performed using nitrogen gas. The primary-cooled wafers are transferred from the load lock chamber to a wafer transfer chamber and placed in a cooling stocker in the wafer transfer chamber. In the cooling stocker, secondary cooling of the wafers is performed by supplying clean air from a clean air unit.

[0004] Furthermore, in Patent Document 1, in order to prevent a decrease in the throughput of a batch-type film formation device, film formation processing is performed on unprocessed wafers in parallel with secondary cooling of wafers. This parallel processing absorbs the waiting time for cooling of wafers during secondary cooling. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 2003-92329 Summary of the Invention [Problem to be solved by the invention]

[0006] Due to changes in equipment configuration and reductions in wafer processing time, the waiting time for wafers to cool in the secondary cooling process can become a limiting factor in throughput. For this reason, it is desirable to shorten the waiting time for wafers to cool in the secondary cooling process.

[0007] The main object of the present invention is to shorten the waiting time for cooling the wafer in the secondary cooling in a wafer processing apparatus. [Means for solving the problem]

[0008] The wafer processing equipment includes: a processing chamber for performing high-temperature processing on a wafer that is circular in plan view; a primary cooling chamber for cooling the wafer removed from the processing chamber; a secondary cooling chamber for cooling the wafers removed from the primary cooling chamber; a base disposed in the secondary cooling chamber, The base has a support portion that is in surface contact with an area including the periphery of an imaginary circle having the same dimensions as the wafer.

[0009] The wafers stored in the cassette are supported near their peripheries. Taking this into consideration, a pedestal is placed in the secondary cooling chamber, and the support portion of the pedestal for the wafer is configured to be in surface contact with an area including the periphery of an imaginary circle having the same dimensions as the wafer. This support portion configuration of the pedestal makes it possible to efficiently cool the peripheries of the wafers supported by the cassette during secondary cooling of the wafers on the pedestal, thereby shortening the waiting time for the wafers to cool during secondary cooling.

[0010] the support portion is provided partially in the circumferential direction of the imaginary circle, The support region of the support portion is parallel to a center line that bisects the imaginary circle and includes arcs on the imaginary circle that correspond to two chords drawn at positions sandwiching the center line.

[0011] The cassette supports the wafers partially, and by taking this into consideration, the support portions are provided partially in the circumferential direction of the imaginary circle, which makes it possible to reduce the size of the base. If support parts are provided all around the circumference of the imaginary circle, the configuration of the wafer transfer mechanism is restricted. In contrast, by providing support parts partially around the circumference of the imaginary circle, wafers can be transferred from locations where no support parts are provided, which improves the design freedom for wafer transport. Furthermore, if the support area at the support section is parallel to the center line that bisects the imaginary circle and includes arcs on the imaginary circle that correspond to two chords drawn on either side of the center line, it becomes possible to cool the area near the periphery of the wafer supported by the cassette.

[0012] Preferably, the two chords are spaced equal distances from the center line.

[0013] When the cassette is viewed from the front in the wafer storage direction, the wafers are supported symmetrically on both sides. Taking this into consideration, the two chords are spaced equal distances from the center line, which reduces the temperature difference between the left and right sides of the wafers supported by the cassette.

[0014] It is desirable to provide a temperature measuring device for measuring the temperature at the support region of the wafer supported by the pedestal.

[0015] When the wafer is cooled on the pedestal, by measuring the temperature of the wafer, it is possible to know with certainty whether the wafer is being cooled sufficiently.

[0016] Preferably, the temperature measuring device measures the overall temperature distribution in the wafer support area.

[0017] By employing a configuration that measures the overall temperature distribution in the wafer support area, the accuracy of the temperature measurement is improved.

[0018] a transfer device that transfers the wafer from the pedestal, It is desirable that the wafer transfer be started based on the measurement result by the temperature measuring device.

[0019] By linking the temperature measurement results with the wafer transport, it is possible to reliably transport a sufficiently cooled wafer to the cassette. [Effects of the Invention]

[0020] The wafers stored in the cassette are supported near their peripheries. Taking this into consideration, a pedestal is placed in the secondary cooling chamber, and the support portion of the pedestal for the wafer is configured to be in surface contact with an area including the periphery of an imaginary circle having the same dimensions as the wafer. This support portion configuration of the pedestal makes it possible to efficiently cool the peripheries of the wafers supported by the cassette during secondary cooling of the wafers on the pedestal, thereby shortening the waiting time for the wafers to cool during secondary cooling. [Brief explanation of the drawings]

[0021] [Figure 1] Schematic plan view of a wafer processing apparatus [Figure 2] 2 is a schematic plan view of the wafer processing apparatus as seen from the line AA shown in FIG. 1. [Figure 3] Illustration of wafer support on a pedestal [Figure 4] Cross section along line BB in Figure 3 [Figure 5] Illustration of wafer support in a cassette [Figure 6] Schematic plan view showing a modified example of the base [Figure 7] Schematic plan view showing a modified example of the wafer processing apparatus. [Figure 8] Illustration of wafer support on a pedestal [Figure 9] Cross section along line BB in Figure 8 [Figure 10] Illustration of wafer support area on the pedestal DETAILED DESCRIPTION OF THE INVENTION

[0022] Known wafer processing equipment (IM) that performs predetermined processing on high-temperature wafers include film deposition equipment, dry etching equipment, and ion implantation equipment. Figure 1 shows an example of the configuration of an ion implantation equipment among these wafer processing equipment (IM). 1 is a schematic plan view showing the periphery of a processing chamber 1 of an ion implantation apparatus. Cassettes 7a-7d store a plurality of wafers W. The wafers W are made of SiC, Si, or the like and are circular in plan view. A circular wafer in plan view refers to a wafer that is approximately circular when viewed from the wafer surface on which ion implantation is performed, and includes wafers having a notch or orientation flat formed at the edge of the wafer surface.

[0023] The transfer robots 4a and 4b take out the wafers W from the cassettes 7a-7d and transfer them to the aligner 5. After the circumferential position of the wafers W is adjusted by the aligner 5, the transfer robots 4a and 4b transfer the wafers W to the vacuum spare chambers 3a and 3b. The spare vacuum chambers 3a and 3b allow the wafer W to be transferred between the processing chamber 1 and the transfer chamber 20 in which the aligner 5 is disposed, which have different vacuum degrees, by switching the vacuum degrees therein. The floors of the vacuum pre-chambers 3a and 3b are moved in the front-to-back direction of the drawing by a drive mechanism (not shown) after the interior of the vacuum pre-chambers 3a and 3b is switched from atmosphere to vacuum or from vacuum to atmosphere.

[0024] The vacuum pre-chamber 3a is equipped with a heater for pre-heating the wafer W. The platen 2 is equipped with either an electrostatic chuck or a mechanical clamping mechanism, or both, for supporting the wafer W. Furthermore, the platen 2 is equipped with a heater for raising the temperature of the wafer W pre-heated in the vacuum pre-chamber 3a to a predetermined temperature.

[0025] A high-temperature wafer W is supported by a platen 2 in the processing chamber 1 and is scanned back and forth across an ion beam transported to the processing chamber 1 by an implantation mechanism unit (not shown). By this back and forth scanning, the entire surface of the wafer W is irradiated with the ion beam, and an ion implantation process is performed on the high-temperature wafer W.

[0026] After the processing in the processing chamber 1 is completed, the wafer W passes through the vacuum auxiliary chamber 3b and the transfer chamber 20 and is collected into one of the cassettes 7a-7d. The vacuum pre-chamber 3b also serves as a primary cooling chamber X for temporarily cooling the wafers W. The primary cooling of the wafers W is performed when the pressure inside the chamber is returned to atmospheric pressure. Specifically, this is performed in the vacuum pre-chamber 3b by blowing nitrogen gas from one end of the vacuum pre-chamber 3b to the other end, parallel to the surface of the wafers W. Alternatively, the primary cooling of the wafers W may be performed by blowing nitrogen gas vertically from above toward the surface of the wafers W. The above-mentioned restoration to atmospheric pressure means that the pressure inside the vacuum preparatory chamber 3b is made equal to the pressure inside the transfer chamber 20 in which the transfer robots 4a, 4b, etc. are placed.

[0027] The processing chamber 1 is equipped with vacuum hands V1 and V2 that can independently rotate in the directions of the arrows shown in the figure. The vacuum hands V1 and V2 are equipped with gripping portions C1 and C2 that grip the periphery of the wafer W. The vacuum hands V1 and V2 grip the wafer W in the vacuum auxiliary chambers 3a and 3b and transport it to the platen 2.

[0028] The primarily cooled wafer W is transferred from the vacuum pre-chamber 3b to a transfer chamber 20 which also serves as a secondary cooling chamber Y. In the transfer chamber 20, a pedestal 6 for performing secondary cooling of the wafer W is arranged. FIG. 2 is a schematic plan view of the wafer processing apparatus IM as seen from line AA in FIG. 1. The pedestal 6 is provided above the aligner 5. A lift pin drive unit 9 is disposed below the pedestal 6. The lift pin drive unit 9 is a device that moves three lift pins up and down when transferring the wafer W between the transfer robots 4a, 4b and the pedestal 6. The number of lift pins is an exemplary number. There is no limit to the number as long as the wafer W can be stably supported on the pins. For example, the wafer W may be configured with a single pin that has a large support area. In order to reduce the contact area with the back surface of the wafer W, the number of pins may be three or more, allowing the wafer W to be supported and transported at three or more points.

[0029] 3 is a plan view of the pedestal 6 when viewed from the direction P shown in FIG. 2. The pedestal 6 includes a support portion 10 that is in surface contact with an area including the periphery of an imaginary circle Wp having the same dimensions as the wafer W. The pedestal 6 also includes a frame body 11 on the outside of the support portion 10. The frame 11 is attached with bolts (not shown) to a member that supports the lower part of the base 6. An opening H is formed inside the support part 10. The lift pins are moved up and down by the lift pin driver 9 through the opening H.

[0030] 4 is a cross-sectional view taken along line BB in FIG. 3. The support part 10 and the frame body 11 have different heights in the vertical direction. They may be configured to have the same height, or the frame body 11 may be configured to be lower than the support part 10. However, in order to prevent the wafer W from falling off the support part 10, it is desirable to make the frame body 11 located outside the support part 10 higher than the support part 10, as shown in FIG.

[0031] 5 is an explanatory diagram of how the cassettes 7a-7d support the wafers W. The cassettes 7a-7d each have multiple shelves for storing the wafers W in the front-to-rear direction of the page. The shelf illustrated in FIG. 5 is a shelf located in the middle of the multiple shelves. 5(A), the cassettes 7a-7d have support portions 7s for supporting the peripheral rear edges of the wafers W. The support portions 7s protrude inward from the left and right sides of the shelf. 5(B) shows the state when the wafers W are stored on the shelves of the cassettes 7a to 7d. As shown in the figure, part of the peripheral edge of the wafers W is supported by the support portions 7s of the cassettes 7a to 7d.

[0032] The shelves of cassettes 7a-7d shown in Figure 5 are illustrative, but other cassettes that store wafers W that are circular in plan view also adopt a configuration that supports the peripheral edges of the wafers W from the left and right sides of the shelves.

[0033] 3 enables support of the entire periphery of the wafer W. By supporting the peripheral edge of the wafer W with the support part 10 of the pedestal 6, heat is transferred from the peripheral edge of the wafer W supported by the support part 10 to the pedestal 6, and the temperature in the vicinity of the peripheral edge of the supported wafer W decreases.

[0034] When the wafers W are collected into the cassettes 7a-7d, as shown in Fig. 5, the shelves of the cassettes 7a-7d storing the wafers W partially support the peripheral edges of the wafers W. The support parts 10 of the pedestal 6 shown in Fig. 3 support the peripheral edges of the wafers W, thereby enabling the vicinity of the peripheral edges of the wafers W to be cooled in a short time. This reduces the waiting time for secondary cooling. In the prior art disclosed in Patent Document 1, the wafer W is supported at three points during secondary cooling, and therefore the cooling effect on the vicinity of the wafer periphery is low.

[0035] Fig. 6 is a schematic plan view showing a modified example of the pedestal 6. The difference between the pedestal 6-1 shown in Fig. 6 and the pedestal 6 shown in Fig. 3 is that the frame 11 of the pedestal 6-1 is provided with heat dissipation fins F. By providing the heat dissipation fins F, the heat capacity of the pedestal 6-1 can be increased, and the transfer of heat from the periphery of the wafer W to the pedestal 6 can be promoted.

[0036] The number of heat dissipation fins F is not limited to that shown in Fig. 6. The number may be less than or greater than that shown. The heat dissipation fins F may be disposed above the frame 11 or below the support portion 10. Alternatively, the fins may be disposed at any position as long as they do not interfere with the transfer of the wafers W by the transfer robots 4a and 4b.

[0037] 2, a temperature measuring device 8 is disposed on the ceiling of a transfer chamber 20 in which the aligner 5 and transfer robots 4a and 4b are disposed. The temperature measuring device 8 is one or more radiation thermometers or thermography cameras. The temperature measuring device 8 is used to measure the temperature near the periphery of the wafer W supported on the pedestal 6. 2, the temperature measuring device 8 is disposed on the inner wall of the transfer chamber 20. However, in order to prevent contamination of the temperature measuring device 8 and to facilitate replacement and troubleshooting in the event of a malfunction, a configuration may be adopted in which an infrared-transmitting window is attached to the ceiling of the transfer chamber 20 and the temperature measuring device 8 is disposed outside the transfer chamber 20.

[0038] Based on the measurement results from the temperature measuring device 8, the wafers W are transported from the pedestal 6 to the cassettes 7a-7d by the transport robots 4a and 4b. The control device C shown in FIG. 1 includes a calculation unit, a memory unit, etc., required for carrying out various processes. A reference value is stored in advance in the memory of the control device C. This reference value is, for example, the heat resistance temperature of the cassettes 7a-7d. The peripheral temperature of the wafer W measured by the temperature measuring device 8 is sent to the control device C as an output signal S1. The control device C compares this reference value with the received measured value, and if the measured value is lower than the reference value, it controls the transfer robots 4a and 4b to output a control signal S2 to start transferring the wafer W.

[0039] The temperature measuring device 8 measures the temperature at any one point on the periphery of the wafer W supported by the pedestal 6. However, considering the possibility that the measurement point may be a singular point, the temperature may be measured at multiple points. In this case, the measurement results at all measured points may be compared with a reference value, and whether or not the wafer W can be transported may be determined based on whether or not the measurement results at all points are below the reference value. Furthermore, in order to carry out more accurate transport control of the wafer W, it is desirable to use a thermography camera as the temperature measuring device 8 and measure the overall temperature distribution in the support area of ​​the wafer W supported on the pedestal 6. Although it is possible to arrange multiple radiation thermometers and measure the overall temperature distribution in the support area of ​​the wafer W, it is physically difficult to arrange the radiation thermometers closely, and from the viewpoint of ease of maintenance, it is preferable to use a thermographic camera.

[0040] Fig. 7 is a schematic plan view showing a modified example of the wafer processing apparatus IM. The wafer processing apparatus IM2 shown in Fig. 7 differs from the wafer processing apparatus IM shown in Fig. 2 in that it has two pedestals 6a and 6b, one above the other. Increasing the number of pedestals makes it possible to perform secondary cooling of wafers W in parallel. 2, when wafers W are processed consecutively, the next processed wafer W cannot be transported to the pedestal 6 while the previously processed wafer W is undergoing secondary cooling on the pedestal 6, and must wait in the vacuum spare chamber 3b. However, if an additional pedestal 6 for secondary cooling is provided as in the configuration shown in FIG. 7, it is possible to eliminate this waiting period for the wafer W to be transported to the pedestal 6.

[0041] When additional bases 6 are installed, the number does not need to be two, and three or more bases may be installed. 7, the pedestal 6 is disposed above the aligner 5, but the location of the pedestal 6 is not limited to this. The pedestal 6 may be disposed in any location as long as the wafer W can be transported by the transport robots 4a and 4b.

[0042] When additional pedestals 6 are installed in the vertical direction, like the pedestals 6a and 6b shown in FIG. 7, the wafer W may be transferred using the lift pin driving device 9. However, with such a configuration, the lift pin drive device 9 becomes large in size, and it becomes impossible to transfer the wafer W to the upper pedestal 6a when there is a wafer W on the lower pedestal 6b, etc., which limits the design freedom for transporting the wafer W.

[0043] Therefore, in order to improve the degree of freedom in design for transporting the wafers W, in the wafer processing apparatus IM2 shown in FIG. 7, the transfer of the wafers W to and from the pedestals 6a and 6b is performed only by the transfer robots 4a and 4b. Fig. 8 is a plan view of the base 6a when viewed from the direction P shown in Fig. 7. The base 6b (not shown) has the same configuration as the base 6a. 8, in order to realize the transfer of the wafer W by the transfer robots 4a and 4b, each of the pedestals 6a and 6b is divided into two portions in the circumferential direction of an imaginary circle Wp having the same dimensions as the wafer W. In addition, an open end OP is formed between each divided portion in the circumferential direction of the imaginary circle Wp.

[0044] The base 6a shown in Fig. 8 includes a support portion 10 and a frame body 11, similar to the base 6 shown in Fig. 3. Fig. 9 is a cross-sectional view taken along line BB in Fig. 8. Similar to the configuration shown in Fig. 4, the support portion 10 and the frame body 11 are at different heights.

[0045] 5, the cassettes 7a-7d support the wafers W only partially. That is, the entire peripheral area of ​​the back surface of the wafer W is not supported by the support portions 7s of the cassettes 7a-7d. For this reason, the support portions 10 of the pedestal 6a may be provided so as to support the peripheral areas of the wafers W facing each other.

[0046] The wafer W is transferred between the pedestals 6a and 6b as follows. The transfer robots 4a and 4b have hands that support the wafer W. When transferring the wafer W to the pedestal 6a, the hands of the transfer robots 4a and 4b that support the wafer W are moved horizontally above the pedestal 6a. The hands of the transfer robots 4a and 4b then move downward. At this time, because an opening H and an open end OP are formed in the pedestal 6a, there is no physical interference between the transfer robots 4a and 4b and the pedestal 6a. When the hands of the transfer robots 4a and 4b move below the support part 10, the transfer of the wafer W from the hands of the transfer robots 4a and 4b to the support part 10 is completed.

[0047] When receiving the wafer W from the pedestal 6a, the hands of the transfer robots 4a and 4b are moved horizontally and positioned directly below the wafer W supported on the pedestal 6a. At this time, because the pedestal 6a has an opening H and an open end OP, there is no physical interference between the transfer robots 4a and 4b and the pedestal 6a. Thereafter, the hands of the transfer robots 4a and 4b are moved upward, completing the transfer of the wafer W from the pedestal 6a to the hands of the transfer robots 4a and 4b.

[0048] The support area of ​​the support portion 10 on the base 6a shown in FIG. 8 will be described with reference to FIG. Two chords ST are drawn parallel to a center line CL that bisects an imaginary circle Wp having the same dimensions as the wafer W, and are positioned on either side of the center line CL. The support area of ​​the support part 10 is an area that includes arcs AR (shown by thick lines in FIG. 10) on the imaginary circle Wp that correspond to these chords ST.

[0049] When storing wafers W in cassettes 7a-7d, the transport direction of wafers W is linear, so the transport direction of wafers W by transport robots 4a and 4b is set so that this transport direction is parallel to the center line CL described here. By supporting the wafer W at a location including the arc AR on the pedestal 6a, it becomes possible to sufficiently cool the vicinity of the periphery of the wafer W supported by the support portions 7s of the cassettes 7a-7d.

[0050] 10, the chords ST are drawn at positions spaced at equal distances from the center line CL, but the distances of the chords ST from the center line CL may differ from one another. However, because the wafers W are supported symmetrically in the cassettes 7a-7d, setting the chords ST at equal distances from the center line CL can reduce the temperature difference between the left and right sides of the wafers W supported in the cassettes 7a-7d.

[0051] In the above embodiment, the primary cooling is performed in the vacuum pre-chamber 3b, and the secondary cooling is performed in the pedestals 6, 6-1, 6a, and 6b. However, the present invention is not limited to this configuration, and other configurations may be adopted. For example, a cooling chamber may be additionally provided at a position adjacent to the transfer chamber 20 in which the transfer robots 4a and 4b are disposed, and the primary cooling and secondary cooling may be performed in the additional cooling chamber.

[0052] Although an ion implantation apparatus has been described as an example of the wafer processing apparatuses IM and IM2, the wafer processing apparatus is not limited to an ion implantation apparatus. Other wafer processing apparatuses, such as a film formation apparatus or an etching apparatus, may be used as long as they are configured to cool wafers that have been subjected to high-temperature processing in two stages and collect them in a cassette.

[0053] In the above embodiment, the vacuum preparatory chamber 3b is configured to double as the primary cooling chamber X, but the vacuum preparatory chamber 3a may also double as the primary cooling chamber X. In this case, preheating is carried out in the vacuum preparatory chamber 3b.

[0054] In the above embodiment, the transport of the wafer W is described based on the measurement results of the temperature measuring device 8, but whether or not the wafer W can be transported may also be determined based on the elapsed time since the wafer W was placed on the pedestal 6, 6-1, 6a, or 6b. However, after high-temperature processing, the wafers W are not necessarily flat, and distortion occurs within the wafer surface. Moreover, this distortion varies slightly from wafer to wafer W. Furthermore, in many cases, there are differences in the wafer suppliers, and the types of wafers W handled by the wafer processing equipment IM and IM2 are not the same.

[0055] When considering these points and setting the elapsed time until the peripheral edge of the wafer W is cooled sufficiently, there is a tendency to set the time longer than necessary, which results in a long waiting time for secondary cooling. In contrast, the method of determining whether or not to transport a wafer W based on the measurement results of the temperature measuring device 8 measures the temperature of the wafer W actually being handled, which makes it possible to transport the wafer W at the appropriate time, and is advantageous in terms of shortening the waiting time for secondary cooling.

[0056] The support parts 10 of the pedestals 6, 6-1, 6a, and 6b may be made of a metal with good thermal conductivity, such as aluminum or gold. On the other hand, carbon, which has high wear resistance, may be used to prevent particles from being generated due to friction with the back surface of the wafer W.

[0057] Furthermore, a device having a blowing function similar to the clean air unit described in Patent Document 1 may be added and used in combination for secondary cooling of the wafers W on the pedestals 6, 6-1, 6a, and 6b.

[0058] Furthermore, the present invention is not limited to the above-described embodiment, and it goes without saying that various modifications are possible without departing from the spirit of the present invention. [Explanation of symbols]

[0059] 1 Processing chamber 4a, 4b Transport robot 6, 6a, 6b pedestal 7a, 7b, 7c, 7d cassettes 7s support part 8 Temperature measuring device 10 Support part X Primary cooling room Y Secondary cooling chamber W wafer Wp Virtual Circle CL center line AR Arc ST string H opening OP open end IM, IM2 wafer processing equipment

Claims

1. a processing chamber for performing high-temperature processing on a wafer that is circular in plan view; a primary cooling chamber for cooling the wafer removed from the processing chamber; a secondary cooling chamber for cooling the wafers removed from the primary cooling chamber; a base disposed in the secondary cooling chamber, The wafer processing apparatus, wherein the base has a support portion that comes into surface contact with an area including the periphery of an imaginary circle having the same dimensions as the wafer.

2. the support portion is provided partially in the circumferential direction of the imaginary circle, 2. The wafer processing apparatus according to claim 1, wherein the support area of ​​the support portion is parallel to a center line that bisects the imaginary circle and includes an arc on the imaginary circle corresponding to two chords drawn at positions on either side of the center line.

3. 3. The wafer processing apparatus of claim 2, wherein the two chords are spaced equal distances from the centerline.

4. The wafer processing apparatus according to claim 1 , further comprising a temperature measuring device for measuring the temperature at a region where the wafer is supported by the pedestal.

5. 5. The wafer processing apparatus of claim 4, wherein the temperature measuring device measures the overall temperature distribution in the wafer support area.

6. a transfer device that transfers the wafer from the pedestal, 5. The wafer processing apparatus according to claim 4, wherein the wafer transfer is started based on the measurement result of the temperature measuring device.

Images