JP5875882B2 - Ceramic heater - Google Patents

Description

  The present invention relates to a ceramic heater.

  Conventionally, as a ceramic heater, a ceramic substrate having a wafer mounting surface, a resistance heating element built in the ceramic substrate, a cooling passage formed inside the ceramic substrate, a wafer mounting surface of the ceramic substrate, There is known one provided with a gas introduction path for introducing a cooling gas from the opposite surface toward the cooling passage (see, for example, paragraphs 0024 to 0025 of Patent Document 1). Such a ceramic heater is used, for example, when processing a wafer with plasma. When processing with plasma, the temperature of the wafer rises due to heat input from the plasma to the wafer. Therefore, the wafer may not be maintained at a desired temperature only by on / off control or current control of the resistance heating element. In such a case, in order to lower the temperature of the wafer, an inert gas such as nitrogen gas or argon gas is introduced as a cooling gas from the gas introduction path into the cooling passage.

JP 2003-142564 A

  However, in the ceramic heater described above, the temperature of the wafer may be uneven due to the cooling gas introduced into the cooling passage. That is, in the ceramic heater described above, the cooling passage is formed in a direction along the wafer mounting surface in the ceramic base, whereas the gas introduction path is formed in a direction orthogonal to the wafer mounting surface. . Therefore, the cooling gas that has passed through the gas introduction path hits the wall surface (that is, the ceramic substrate) in the cooling path. In that case, the location where the cooling gas strikes is excessively cooled as compared with other locations, and the temperature of the wafer becomes uneven.

  The present invention has been made to solve such a problem, and a main object of the present invention is to cool the wafer mounting surface without causing a large temperature difference.

The ceramic heater of the present invention is
A ceramic substrate having a wafer mounting surface;
A resistance heating element built in the ceramic substrate and wired over the entire wafer mounting surface;
A cooling passage formed inside the ceramic substrate and configured to allow cooling gas to pass over the entire wafer mounting surface;
A gas introduction path for introducing the cooling gas from a surface of the ceramic base opposite to the wafer mounting surface toward the cooling passage;
A ceramic heater comprising:
The gas introduction path is provided with an avoidance portion for avoiding the cooling gas that has passed through the gas introduction path from hitting the ceramic substrate.

  In this ceramic heater, the wafer placed on the wafer placement surface is heated by the resistance heating element, and the wafer placed on the wafer placement surface is cooled by the cooling gas introduced from the gas introduction path to the cooling passage. Here, the gas introduction path is provided with an avoidance portion for avoiding the cooling gas that has passed through the gas introduction path from hitting the ceramic substrate. When the cooling gas hits the ceramic substrate, the hitting portion is excessively cooled. However, since the avoiding portion is provided here, such an excessively cooled portion does not occur. Therefore, the wafer mounting surface can be cooled without causing a large temperature difference.

  In the ceramic heater according to the present invention, the avoidance portion may be formed by curving the gas introduction path along the cooling passage. If it carries out like this, since the cooling gas introduce | transduced into a cooling channel from a gas introduction path does not collide in a cooling channel, it will become difficult to produce the location cooled too much.

  In the ceramic heater of the present invention, the avoiding portion includes a collision surface on which the cooling gas that has passed through the gas introduction path abuts, and a step portion provided on the back surface of the collision surface, and the step portion and the ceramic base body A space may be formed between the two. In this case, since the cooling gas hits the collision surface, the collision surface may be excessively cooled, but there is a space between the stepped portion provided on the back surface of the collision surface and the ceramic base. For this reason, the temperature of the collision surface is transmitted to the ceramic substrate through the space. Therefore, the ceramic substrate is not easily affected by the excessively cooled collision surface.

  In the ceramic heater according to the present invention, the cooling passage may be constituted by a plurality of divided passages, and the avoidance portion may be provided at a location connected to each divided passage in the gas introduction passage. Since the cooling gas is heated while passing through the cooling passage, the cooling efficiency is inferior to that of the inlet near the outlet of the cooling passage. However, since the cooling passage is composed of a plurality of divided passages here, there is a temperature difference between the inlet and the outlet in each divided passage, but the temperature difference is small compared to the case where it is not divided into a plurality of divided passages. Become.

  In such a case, the division passage may be a passage provided corresponding to each sector area when the wafer mounting surface is equally divided into a predetermined number of sector areas. By doing so, each divided passage cools the fan-shaped region of the same size, so that a temperature difference hardly occurs in each fan-shaped region. Note that the equal division includes not only the case where the division is made to be exactly the same, but also the case where the division is made to the extent that it is considered to be the same based on social wisdom.

  In the ceramic heater of the present invention, the cross-sectional area of the gas outlet of the gas introduction path is formed to be smaller than the cross-sectional area of the cooling path at the connection point between the gas introduction path and the cooling passage. May be. When the cross-sectional area of the gas outlet of the gas introduction path is the same as the cross-sectional area of the cooling passage, the cooling gas tends to contact the wall of the cooling passage as soon as it enters the cooling passage from the gas introduction path. It tends to cause a temperature drop. However, if the cross-sectional area of the gas outlet of the gas introduction path is smaller than the cross-sectional area of the cooling passage, the cooling gas remains straight even if it enters the cooling passage from the gas introduction path. It does not come into contact immediately, and it is difficult to cause a temperature drop at the connection point.

It is a longitudinal cross-sectional view of the member 10 for semiconductor manufacturing apparatuses. It is AA sectional drawing. It is a longitudinal cross-sectional view of the member 60 for semiconductor manufacturing apparatuses. It is BB sectional drawing. 3 is a bottom view of a ceramic disk 76. FIG. It is explanatory drawing of the branch nozzle 88, (a) is a top view, (b) is CC sectional drawing. It is explanatory drawing of the modification of 1st Embodiment. It is explanatory drawing of the modification of 2nd Embodiment. FIG. 3 is a temperature distribution diagram of a wafer mounting surface in Example 1. 6 is a longitudinal sectional view of a member for a semiconductor manufacturing apparatus of Comparative Example 1. FIG. 6 is a temperature distribution diagram of a wafer placement surface in Comparative Example 1. FIG. 6 is a temperature distribution diagram of a wafer placement surface in Example 2. FIG. 6 is a temperature distribution diagram of a wafer placement surface in Example 3. FIG.

[First Embodiment]
1 is a longitudinal sectional view of a semiconductor manufacturing apparatus member 10, and FIG. 2 is an AA sectional view (a gas introduction path 34 is not shown). In the description, up / down, left / right, and front / back are sometimes used. However, this is only used to indicate a relative positional relationship. For example, the top is down, the left is right, and the front is back. You can replace it.

  The semiconductor manufacturing apparatus member 10 includes a ceramic heater 20 and a hollow shaft 40 joined to the lower surface of the ceramic heater 20.

  The ceramic heater 20 is cooled by a ceramic base 22 having a wafer mounting surface 22 a, a resistance heating element 28 built in the ceramic base 22, a cooling passage 30 formed inside the ceramic base 22, and the cooling passage 30. And a gas introduction path 34 for introducing gas.

  The ceramic substrate 22 is a disk-shaped plate made of a ceramic material typified by aluminum nitride or alumina. The ceramic base 22 is formed by joining a pair of ceramic disks 24 and 26. A resistance heating element 28 is embedded in the upper ceramic disk 24. On the upper surface of the lower ceramic disk 26, a cooling passage groove 32 is formed. The groove 32 becomes a cooling passage 30 by joining the lower surface of the upper ceramic disk 24 and the upper surface of the lower ceramic disk 26.

  The resistance heating element 28 is formed so as to reach from the one end 28a to the other end 28b after being wired over the entire wafer mounting surface 22a in the manner of one-stroke writing. Note that power is supplied to the one end 28a and the other end 28b via a power supply line (not shown). This power supply line is disposed inside the hollow of the shaft 40.

  The cooling passage 30 is formed so that the cooling gas passes over the entire wafer placement surface 22a. The groove 32 constituting the cooling passage 30 is formed in the shape shown in FIG. That is, the groove 32 extends from the center of the ceramic base 22 to the vicinity of the outer periphery along the radial direction, and after making about one turn along the circumferential direction, makes a U-turn, and again makes about one turn along the circumferential direction. The pattern is repeated so that it finally returns to the center. A central portion 32c of the groove 32 facing the hollow interior of the shaft 40 passes through the ceramic disk 26 in the vertical direction. The central portion 32 c does not constitute the cooling passage 30. In FIG. 2, a white arrow portion is a gas inlet 30 a (that is, a connecting portion with the gas introduction path 34) of the cooling passage 30, and a black arrow portion is a gas outlet 30 b.

  The gas introduction path 34 includes a gas pipe 36 extending from the lower side toward the ceramic base 22 through the hollow interior of the shaft 40, and a nozzle 38 provided at the tip of the gas pipe 36. Such a gas introduction path 34 is formed of, for example, SUS or Inconel. The distal end side of the gas pipe 36 is curved along the cooling passage 30 at a curved portion 36a, and the direction is changed by about 90 °. Since the curved portion 36 a exists, the cooling gas that has passed through the gas introduction path 34 is prevented from hitting the ceramic base 22. This curved portion 36a corresponds to the avoidance portion of the present invention. The nozzle 38 is fixed to the gas inlet 30 a of the cooling passage 30. The cross-sectional area of the gas outlet of the nozzle 38 is formed to be smaller than the cross-sectional area of the cooling passage 30.

  Next, a manufacturing example of the semiconductor manufacturing apparatus member 10 will be described. First, the ceramic raw material powder used as the raw material of the ceramic discs 24 and 26 is prepared. The ceramic disk 24 is obtained by embedding the resistance heating element 28 in a ceramic raw material powder in a mold, pressurizing the ceramic raw material powder to form a disk-shaped ceramic molded body, and hot-press firing the ceramic molded body. . Alternatively, two ceramic molded bodies may be produced, and the resistance heating element 28 sandwiched between them may be hot-press fired to form a ceramic disk 24, or one ceramic sintered body and one ceramic molded body. And a ceramic disk 24 may be obtained by hot-press firing the sandwiched resistance heating element 28 therebetween. The ceramic disk 26 is obtained by forming a ceramic raw material powder into a disk shape, hot-press firing it into a sintered body, and then forming grooves 32 on the upper surface by grinding or blasting. Subsequently, the ceramic base 22 is obtained by solid phase bonding of the ceramic disks 24 and 26 (refer to JP-A-8-73280 for details of the solid phase bonding). Note that not only solid phase bonding but also row bonding (including TCB bonding) can be applied. Subsequently, the shaft 40 is joined to the center of the lower surface of the ceramic substrate 22. Finally, the gas pipe 36 having the nozzle 38 at the tip and formed with the curved portion 36a is inserted from below into the hollow interior of the shaft 40 upward, and the nozzle 38 is inserted into the gas inlet 30a of the cooling passage 30 and fixed. .

  Next, the usage example of the member 10 for semiconductor manufacturing apparatuses is demonstrated. The semiconductor manufacturing apparatus member 10 is used, for example, when a wafer is subjected to plasma processing. In that case, first, a wafer is mounted on the wafer mounting surface 22a of the ceramic heater 20, and the current to the resistance heating element 28 is controlled so that the temperature of the wafer becomes a set temperature (for example, 200 to 300 ° C.). The amount of cooling gas supplied to the cooling passage 30 is controlled. Specifically, the wafer placed on the wafer placement surface 22 a is heated by the resistance heating element 28 and placed on the wafer placement surface 22 a by the cooling gas introduced from the gas introduction path 34 to the cooling passage 30. Cool the wafer. Here, in the present embodiment, since the curved portion 36 a exists in the gas pipe 36 constituting the gas introduction path 34, the cooling gas that has passed through the gas introduction path 34 is prevented from hitting the ceramic substrate 22. .

  According to the semiconductor manufacturing apparatus member 10 of the present embodiment described above, since the cooling gas that has passed through the gas introduction path 34 is prevented from hitting the ceramic substrate 22, a large temperature is applied to the wafer mounting surface 22 a. Cooling can be performed without causing a difference. That is, when the cooling gas hits the ceramic substrate 22, the hitting portion is excessively cooled. However, since the hitting is avoided here, such an excessively cooled portion does not occur.

  Further, at the gas inlet 30 a of the cooling passage 30, the cross-sectional area of the gas outlet of the nozzle 38 of the gas introduction path 34 is smaller than the cross-sectional area of the cooling passage 30. Hateful. That is, when both cross-sectional areas have the same size, the cooling gas contacts the wall of the cooling passage 30 as soon as it enters the cooling passage 30 from the gas introduction passage 34, which causes a temperature drop of the gas inlet 30 a. Cheap. However, in this embodiment, since the cross-sectional area of the gas outlet of the nozzle 38 of the gas introduction path 34 is smaller than the cross-sectional area of the cooling passage 30, the cooling gas that has entered the cooling passage 30 from the gas introduction path 34 is straightly traveling. Is maintained to some extent. For this reason, the cooling gas does not immediately contact the wall of the cooling passage 30 and the temperature at the gas inlet 30a is hardly lowered.

[Second Embodiment]
3 is a longitudinal sectional view of the semiconductor manufacturing apparatus member 60, FIG. 4 is a sectional view taken along line BB (the gas introduction path 84 is not shown), FIG. 5 is a bottom view of the ceramic disk 76, and FIG. It is a figure, (a) is a top view, (b) is CC sectional drawing.

  The semiconductor manufacturing apparatus member 60 includes a ceramic heater 70 and a hollow shaft 90 joined to the lower surface of the ceramic heater 70.

  The ceramic heater 70 is cooled by a ceramic base 72 having a wafer mounting surface 72 a, a resistance heating element 78 built in the ceramic base 72, a cooling passage 80 formed inside the ceramic base 72, and the cooling passage 80. And a gas introduction path 84 for introducing gas.

  The ceramic substrate 72 is a disk-shaped plate made of a ceramic material typified by aluminum nitride or alumina. The ceramic base 72 is formed by joining a pair of ceramic disks 74 and 76. A resistance heating element 78 is embedded in the upper ceramic disk 74. A cooling passage groove 82 is formed on the upper surface of the lower ceramic disk 76. The groove 82 becomes a cooling passage 80 by joining the lower surface of the upper ceramic disk 74 and the upper surface of the lower ceramic disk 76.

  The resistance heating element 78 is formed so as to extend from one end 78a to the other end 78b after being wired over the entire wafer mounting surface 72a in the manner of one-stroke writing. Note that power is supplied to the one end 78a and the other end 78b via a power supply line (not shown). This power supply line is disposed inside the hollow of the shaft 90.

  The cooling passage 80 is formed so that the cooling gas passes through the entire wafer mounting surface 72a. The groove 82 constituting the cooling passage 80 is formed in the shape shown in FIG. A narrow cross-shaped central portion 82 c facing the hollow inside of the shaft 90 in the groove 82 is a portion into which the branch nozzle 88 is fitted, and thus does not constitute the cooling passage 80. That is, the cooling passage 80 is a portion of the groove 82 having a wide groove width excluding the central portion 82c. The cooling passage 80 is configured by dividing passages 81 formed in each fan-shaped region by equally dividing the wafer mounting surface 72a into four fan-shaped regions. Each divided passage 81 extends from the connecting portion 81a with the cross-shaped central portion 82c to the vicinity of the outer periphery along the radial direction, and then makes a U-turn after about one-quarter round along the circumferential direction. A pattern of approximately one-fourth round along the direction is repeated, and is finally formed to reach the end 81b near the center. The cross-shaped central portion 82c penetrates the ceramic disk 76 in the vertical direction (see FIG. 5). Further, the end 81b of each divided passage 81 also penetrates the ceramic disk 76 in the vertical direction (see FIG. 5).

  The gas introduction path 84 includes a gas pipe 86 that linearly extends from below in the hollow interior of the shaft 90 toward the ceramic base 72, and a branch nozzle 88 provided at the tip of the gas pipe 86. Such a gas introduction path 84 is formed of, for example, SUS or Inconel. As shown in FIG. 6, the branch nozzle 88 has a cross shape when viewed from above, and a tip of a gas pipe 86 extending in the vertical direction is connected to the center of the lower surface, and branches in four directions, front, rear, left, and right. . A counterbore, that is, a stepped portion 88a is provided on the upper surface of the branch nozzle 88, and a space S exists between the stepped portion 88a and the ceramic base body 72 (ceramic disc 74) as shown in the partial enlarged view of FIG. ing. The cooling gas flowing from the bottom to the top of the gas pipe 86 collides with the collision surface 88b that is the inner side of the stepped portion 88a, but the space S is present, so that it does not hit the ceramic substrate 72. The step portion 88a and the collision surface 88b correspond to the avoidance portion of the present invention. The branch nozzle 88 is fixed in a state of being fitted into the cross-shaped central portion 82c of the groove 82. The sectional area of the gas outlet of the branch nozzle 88 is formed to be smaller than the sectional area of the cooling passage 80.

  An example of manufacturing the semiconductor manufacturing apparatus member 60 is substantially the same as that in the first embodiment, and thus the description thereof is omitted here.

  Next, a usage example of the semiconductor manufacturing apparatus member 60 will be described. The semiconductor manufacturing apparatus member 60 is used, for example, when plasma processing is performed on a wafer. In that case, first, a wafer is mounted on the wafer mounting surface 72a of the ceramic heater 70, and the current to the resistance heating element 78 is controlled so that the wafer temperature becomes a set temperature (for example, 200 to 300 ° C.). The amount of cooling gas supplied to the cooling passage 80 is controlled. Specifically, the wafer placed on the wafer placement surface 72 a is heated by the resistance heating element 78 and placed on the wafer placement surface 72 a by the cooling gas introduced from the gas introduction path 84 to the cooling passage 80. Cool the wafer. Here, as shown in the partially enlarged view of FIG. 3, the ceramic heater 70 of the present embodiment is provided on the collision surface 88 b of the branch nozzle 88 against which the cooling gas that has passed through the gas introduction path 84 hits, and on the rear surface of the collision surface 88 b. A step S 88 a is provided, and a space S is formed between the step 88 a and the ceramic base 72. Then, after the cooling gas hits the collision surface 88b, the cooling gas enters the cooling passage 80 (dividing passage 81). For this reason, the collision surface 88b may be excessively cooled, but a space S exists between the stepped portion 88a provided on the back surface of the collision surface 88b and the ceramic base body 72, and therefore the temperature of the collision surface 88b. Is transmitted to the ceramic substrate 72 through the space S.

  According to the semiconductor manufacturing apparatus member 60 of the present embodiment described above, the cooling gas that has passed through the gas introduction path 84 is avoided from hitting the ceramic substrate 72, so that a large temperature is applied to the wafer mounting surface 72 a. Cooling can be performed without causing a difference. That is, since the cooling gas hits the collision surface 88b, the collision surface 88b may be excessively cooled, but since there is a space S between the stepped portion 88a and the ceramic base body 72, the collision surface 88b The temperature is transmitted to the ceramic substrate 72 through the space S. Therefore, the ceramic base 72 is not easily affected by the excessively cooled collision surface 88b, and can be cooled without causing a large temperature difference on the wafer mounting surface 72a.

  In addition, since the cooling passage 80 is composed of four divided passages 81, a temperature difference occurs between the inlet and the outlet when the divided passages 81 are viewed, but the temperature difference is larger than that when not divided into a plurality of portions. Becomes smaller.

  Further, the dividing passage 81 is provided corresponding to each fan-shaped area when the wafer mounting surface 72a is equally divided into four fan-shaped areas and cools the fan-shaped areas of the same size. Temperature differences are unlikely to occur in each region.

  Furthermore, since the cross-sectional area of the gas outlet of the branch nozzle 88 is smaller than the cross-sectional area of the split passage 81 at the connection portion between each division passage 81 and the branch nozzle 88, the temperature drop at the connection portion also in this respect. Hard to invite. The reason is as described in the first embodiment.

  It should be noted that the present invention is not limited to the above-described embodiment, and it goes without saying that the present invention can be implemented in various modes as long as it belongs to the technical scope of the present invention.

  For example, in the first embodiment described above, a gas introduction path 134 similar to the gas introduction path 84 of the second embodiment as shown in FIG. In this case, since the cooling gas that has passed through the gas pipe 136 from the bottom collides with the collision surface 138b of the nozzle 138, the collision surface 138b is easily cooled excessively. However, a space S exists between the stepped portion 138a provided on the back surface of the collision surface 138b and the ceramic base 22 (ceramic disk 24). Therefore, the temperature of the collision surface 138b is transmitted to the ceramic disk 24 of the ceramic base 72 through the space S. Therefore, the ceramic base 72 is not easily affected by the excessively cooled collision surface 138b. In addition, since the cross-sectional area of the gas outlet of the nozzle 138 is formed to be smaller than the cross-sectional area of the cooling passage 30, it is difficult to cause a temperature drop at the connection point in this respect as well.

  In the second embodiment described above, a gas introduction path 184 similar to the gas introduction path 34 of the first embodiment as shown in FIG. In this case, the gas introduction path 184 includes a gas pipe 186 that extends from the lower side toward the ceramic base 22 through the hollow interior of the shaft 90, and a nozzle 188 provided at each tip of the gas pipe 186. And. Each branch portion of the gas pipe 186 is curved along the respective divided passages 81 of the cooling passage 80 at a curved portion 186a, and the direction is changed by about 90 °. Since the curved portion 186 a exists, the cooling gas that has passed through the gas introduction path 184 is prevented from hitting the ceramic base 22. Moreover, since the cross-sectional area of the gas outlet of the nozzle 188 is formed so as to be smaller than the cross-sectional area of the divided passage 81, it is difficult to cause a temperature drop at the connection point in this respect as well.

  In the first and second embodiments described above, the resistance heating elements 28 and 78 are built in the ceramic bases 22 and 72 of the ceramic heaters 20 and 70, but in addition, an electrostatic electrode for functioning as an electrostatic chuck is provided. It may be built in or a high frequency electrode for generating plasma may be built in.

  In the first and second embodiments described above, the resistance heating elements 28 and 78 are wired over the entire surface of the wafer mounting surfaces 22a and 72a in the manner of one stroke, but the wafer mounting surface 22a is divided into a plurality of regions. You may wire a resistance heating element for each area | region in the way of one-stroke writing.

[Example 1]
A member 10 for a semiconductor manufacturing apparatus according to the first embodiment was produced. The ceramic substrate 22 was used having a diameter of 350 mm and a thickness of 20 mm, and the shaft 40 having a height of 200 mm, an outer diameter of 40 mm, an inner diameter of 34 mm, and a flange having an outer diameter of 70 mm was used. The cooling passage 30 has a rectangular cross section, a width of 10 mm, a depth of 5 mm, and the nozzle 38 has an inner diameter of 3 mm. In this semiconductor manufacturing apparatus member 10, the current to the resistance heating element 28 and the supply amount of the cooling gas to the cooling passage 30 are controlled so that the surface temperature of the wafer mounting surface 22 a becomes 200 ° C., and the wafer at that time The temperature distribution on the mounting surface 22a was measured. The result is shown in FIG. FIG. 9 also shows the cooling passage 30 (groove 32) and the gas inlet 30a. As is apparent from FIG. 9, the temperature around the gas inlet 30a of the cooling passage 30 tended to be slightly lower, but the temperature range was 4 ° C.

[Comparative Example 1]
In the semiconductor manufacturing apparatus member 10 of the first embodiment, instead of the gas pipe 36 and the nozzle 38, as shown in FIG. 10, the gas that penetrates the inside of the peripheral wall of the shaft 40 in the gas inlet 30 a of the cooling passage 30 in the vertical direction. An inlet passage 234 was connected, and a gas outlet passage 235 penetrating the interior of the peripheral wall of the shaft 40 in the vertical direction was prepared to the gas outlet 30b of the cooling passage 30. The dimensions of the ceramic substrate 22, the shaft 40, and the cooling passage 30 were the same as in Example 1, and the gas introduction passage 234 had an inner diameter of 5 mm. Then, the temperature distribution was measured in the same manner as in Example 1. The result is shown in FIG. FIG. 11 also shows the cooling passage 30 (groove 32) and the gas inlet 30a. As is apparent from FIG. 11, the temperature of the portion of the cooling passage 30 where the cooling gas hits the ceramic substrate (near the gas inlet 30a) was extremely lowered. Therefore, the temperature range was 7 ° C.

  In Comparative Example 1, since the cooling gas supplied from the gas introduction path 234 hits the ceramic substrate 22, the hitting part was extremely cooled, and as a result, the temperature range became a large value. On the other hand, in the first embodiment, the cooling gas supplied from the gas introduction path 34 does not hit the ceramic base 22, and the sectional area of the gas outlet of the nozzle 38 is larger than the sectional area of the cooling passage 30. The temperature range is kept small, for example, because the cooling gas does not immediately contact the wall of the cooling passage 30.

[Example 2]
In the same manner as in Example 1, the semiconductor manufacturing apparatus member 10 of the first embodiment was produced. However, the nozzle had an inner diameter of 2 mm. Then, the temperature distribution was measured in the same manner as in Example 1. The result is shown in FIG. FIG. 12 also shows the cooling passage 30 (groove 32) and the gas inlet 30a. As apparent from FIG. 12, the temperature around the gas inlet 30a of the cooling passage 30 tended to be slightly lower, but the temperature range was smaller than that of Example 1 and 3 ° C. As described above, the temperature range is smaller than that of the first embodiment because the cross-sectional area of the gas outlet of the nozzle 38 is further reduced, so that the straightness of the cooling gas becomes remarkable. This is thought to be because the section until it touched the wall was extended.

[Example 3]
The member 60 for semiconductor manufacturing apparatus of 2nd Embodiment was produced. A ceramic substrate 72 having a diameter of 350 mm and a thickness of 20 mm was used, and a shaft 90 having a height of 200 mm, an outer diameter of 40 mm, an inner diameter of 34 mm, and a flange having an outer diameter of 70 mm was used. The cooling passage 80 has a rectangular cross section, a width of 10 mm, a depth of 5 mm, and the branch nozzle 88 has an inner diameter of 2 mm. Then, the temperature distribution was measured in the same manner as in Example 1. The result is shown in FIG. In FIG. 13, the cooling passage 80 (groove 82) and the division passage 81 are also shown. As is apparent from FIG. 13, the temperature around the entrance of each divided passage 81 tended to be slightly lower, but the temperature range was 1.2 ° C., which was smaller than those in Examples 1 and 2. The reason for this is that the cooling gas supplied from the gas introduction path 84 does not hit the ceramic substrate 72 as in the first and second embodiments, and the cross-sectional area of the gas outlet of the branch nozzle 88 is the disconnection of the cooling passage 80. Although it is smaller than the area and the cooling gas does not immediately contact the wall of the cooling passage 80, the following causes are conceivable. That is, it is considered that the cooling passage 80 is divided into four division passages 81, so that the temperature of the cooling gas hardly rises while passing through the division passage 81, and the cooling efficiency in the vicinity of the outlet of the division passage 81 is improved. In Example 3, the wafer mounting surface is divided into an in area (a small circular area having a common center with the disk-shaped wafer mounting surface) and an out area (an annular area outside the small circular area). When the resistance heating element is wired for each region, the temperature range becomes 0.8 ° C. when the in-region and the out-region can be controlled in temperature independently (two-zone structure), and the thermal uniformity is further improved.

[Example 4]
In the third embodiment, the cooling passage 80 is divided into four divided passages 81. In the fourth embodiment, the cooling passage is divided into six divided passages. Specifically, the wafer mounting surface was equally divided into six sector regions, and a division passage was provided in each of the six sector regions. The branch nozzle used was branched radially in six directions. As a result, in the temperature distribution, contour lines of three temperatures of 190.2 ° C., 190.6 ° C., and 191 ° C. appeared concentrically with the wafer mounting surface and the center in common. The temperature range was 0.8 ° C., and the thermal uniformity was further improved as compared with Example 3. In Example 4, the temperature range is further improved when the above-described two-zone structure is used.

DESCRIPTION OF SYMBOLS 10 Semiconductor manufacturing apparatus member, 20 Ceramic heater, 22 Ceramic base | substrate, 22a Wafer mounting surface, 24, 26 Ceramic disk, 28 Resistance heating element, 28a One end, 28b Other end, 30 Cooling passage, 30a Gas inlet, 30b Gas outlet 30c Center part, 32 grooves, 34 gas introduction path, 36 gas pipe, 36a curve part, 38 nozzle, 40 shaft, 60 member for semiconductor manufacturing equipment, 70 ceramic heater, 72 ceramic base, 72a wafer mounting surface, 74, 76 Ceramic disk, 78 resistance heating element, 78a one end, 78b other end, 80 cooling passage, 81 division passage, 81a connection place, 81b end, 82 groove, 82c central portion, 84 gas introduction passage, 86 gas pipe, 88 branch nozzle, 88a Stepped portion, 88b Colliding surface, 9 Shaft, 134 a gas introducing path, 136 gas pipe, 138 nozzles, 138a stepped portion, 138b collision surface, 184 gas introduction passage, 186 gas pipe, 186a curved section, 188 nozzles, 234 gas introduction passage, 235 the gas discharge channel, S Space

Claims (5)

A ceramic substrate having a wafer mounting surface;
A resistance heating element built in the ceramic substrate and wired over the entire wafer mounting surface;
A cooling passage formed inside the ceramic substrate and configured to allow cooling gas to pass over the entire wafer mounting surface;
A gas introduction path for introducing the cooling gas from a surface of the ceramic base opposite to the wafer mounting surface toward the cooling passage;
A ceramic heater comprising:
The gas introduction path is provided with an avoidance portion for avoiding the cooling gas that has passed through the gas introduction path from hitting the ceramic substrate ,
The avoiding portion includes a collision surface on which the cooling gas that has passed through the gas introduction path abuts, and a step portion provided on the back surface of the collision surface, and there is a space between the step portion and the ceramic base. Formed,
Ceramic heater.   A ceramic substrate having a wafer mounting surface;
  A resistance heating element built in the ceramic substrate and wired over the entire wafer mounting surface;
  A cooling passage formed inside the ceramic substrate and configured to allow cooling gas to pass over the entire wafer mounting surface;
  A gas introduction path for introducing the cooling gas from a surface of the ceramic base opposite to the wafer mounting surface toward the cooling passage;
  A ceramic heater comprising:
  The gas introduction path is provided with an avoidance portion for avoiding the cooling gas that has passed through the gas introduction path from hitting the ceramic substrate,
  At the connection point between the gas introduction path and the cooling passage, the cross-sectional area of the gas outlet of the gas introduction path is formed to be smaller than the cross-sectional area of the cooling passage.
  Ceramic heater. The avoidance portion is formed by curving the gas introduction path along the cooling passage.
The ceramic heater according to claim 2 . The cooling passage is composed of a plurality of divided passages, and the avoidance portion is provided at a location where the gas introduction passage is connected to each divided passage.
The ceramic heater according to any one of claims 1 to 3. The division passage is a passage provided corresponding to each sector when the wafer mounting surface is equally divided into a predetermined number of sector regions.
The ceramic heater according to claim 4.

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