JP2006049270A - Heater, and wafer heater and wafer heating device using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem wherein it is difficult to reduce the temperature difference in a wafer surface down to be within 0.3°C, because the temperature difference on the wafer surface is very large. <P>SOLUTION: This heater has a strip-like resistance heating element formed on a plate-shaped body, the strip, formed by the resistance heating element, has grooves that are nearly in parallel with the longitudinal direction, and the grooves are positioned eccentrically on the center side of the plate-shaped body. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a heater that energizes and heats a resistance heating element, and is mainly used in a wafer heating apparatus used when heating a wafer. For example, a thin film is formed on a wafer such as a semiconductor wafer, a liquid crystal device, or a circuit board. And a heater suitable for forming a resist film by drying and baking a resist solution applied on the wafer.

  Ceramic heaters for heating semiconductor wafers (hereinafter abbreviated as “wafers”) are used in semiconductor thin film deposition processing, etching processing, resist film baking processing, and the like in the manufacturing process of semiconductor manufacturing equipment. .

  The conventional semiconductor manufacturing apparatus has a batch type that heats a plurality of wafers at once and a sheet type that heats one wafer at a time. The single wafer type has excellent temperature controllability, so wiring of semiconductor elements is possible. Ceramic heaters are widely used in accordance with demands for miniaturization of wafers and improvement in accuracy of wafer heat treatment temperature.

  As such a ceramic heater, for example, Patent Document 1 and Patent Document 2 propose a ceramic heater as shown in FIG.

  The ceramic heater 71 includes a plate-shaped ceramic body 72 and a metal case 79 as main components, and nitride ceramics or carbide ceramics are formed in an opening of a bottomed metal case 79 made of a metal such as aluminum. The plate-shaped ceramic body 72 is fixed with a bolt 80 via a heat insulating connecting member 74 made of resin, and the upper surface thereof is used as a mounting surface 73 on which the wafer W is placed, and the lower surface of the plate-shaped ceramic body 72 is For example, a concentric resistance heating element 75 as shown in FIG. 7 is provided.

  Furthermore, a power supply terminal 77 is brazed to the terminal portion of the resistance heating element 75, and the power supply terminal 77 is inserted into a lead wire drawing hole 76 formed in the bottom portion 79 a of the metal case 79. 78 to be electrically connected.

  By the way, in such a ceramic heater 71, it is important to make the temperature distribution of the wafer uniform in order to form a homogeneous film on the entire surface of the wafer W and to make the heating reaction state of the resist film uniform. is there. Therefore, until now, in order to reduce the temperature difference in the surface of the wafer, the resistance distribution of the resistance heating element 75 is adjusted, or the temperature of the resistance heating element 75 is divided and controlled. However, the resistance heating element produced by the printing method has a problem that the film thickness varies and a resistance value as designed cannot be obtained. Therefore, as a method for adjusting the resistance distribution, Patent Document 3, Patent Document 4 and Patent Document 5, a method of adjusting the resistance by forming a groove with a laser beam is disclosed.

In addition, a method of making the resistance heating element corrugated and trimming the corrugated portion with a laser as in Patent Document 6, or forming a plurality of grooves m with a laser at the end of the band of the resistance heating element as shown in FIG. Patent Document 7 discloses a method of improving the temperature distribution of the wafer W by using a ceramic heater with resistance adjustment.
JP 2001-203156 A JP 2001-313249 A JP 2001-244059 A JP 2002-141159 A JP 2002-151235 A JP 2002-43031 A JP 2002-203666 A

  However, in the methods such as Patent Document 6 and Patent Document 7, it is possible to partially adjust the resistance value of the resistance heating element and obtain the soaking accuracy in the vicinity of the portion, but the temperature distribution over the entire wafer surface. It was difficult to make the temperature uniform and to reduce the temperature difference on the wafer surface to 0.3 ° C.

  In addition, the ceramic heater formed by the above method has a slight difference in resistance value between the above-mentioned parts while heating and cooling are repeated, and this causes the heat balance on the wafer surface to collapse and the temperature difference to increase. There was a problem.

  Therefore, as a result of intensive studies on the above problems, the inventor of the present invention has a strip-like resistance heating element on the surface of the plate-like body, and the resistance heating element has grooves substantially parallel to the longitudinal direction. The groove is unevenly distributed on the center side of the plate-like body.

  The plate-like body is provided with a strip-like resistance heating element, the resistance heating element has a groove substantially parallel to the longitudinal direction, and the groove is unevenly distributed on the outer peripheral side of the plate-like body. To do.

  The groove may be a groove capable of adjusting a resistance value of the resistance heating element.

  Further, a plurality of the grooves are provided substantially in parallel with the longitudinal direction of the resistance heating element, and a group of a plurality of grooves adjacent to each other is formed.

  The group is divided into a plurality along the longitudinal direction of the band of the resistance heating element, and the distance between the group and the group is smaller than the width of the band.

  Further, the length of the group is 30 to 97% of the total length of the center line of the one band in which the group is formed.

  In addition, the resistance heating element includes an arc-shaped band disposed substantially concentrically and a folded arc-shaped band connecting them, and a pair of folded arc-shaped positions located on the same circumference in at least one place. The distance between the bands is smaller than the distance between the arc-shaped bands disposed substantially concentrically.

  The distance between the pair of folded arc-shaped bands located on the same circumference of the resistance heating element is smaller than the distance between the arc-shaped bands disposed substantially concentrically at all locations. Features.

The distance between the pair of folded arc-shaped bands located on the same circumference is 30 to 80% of the distance between the arc-shaped bands disposed substantially concentrically. In addition, the resistance heating element formed in a substantially concentric circle has a concentric circular outermost resistance heating element with a concentric circle of the resistance heating element excluding the outermost resistance heating element. It is characterized by being smaller than the interval between the strips.

  The heater for heating a wafer according to the present invention has one main surface of the plate-like body as a wafer mounting surface, and a belt-like resistance heating element on the other main surface of the plate-like body, Consisting of an arc-shaped band disposed concentrically and a folded band connecting them, the groove formed in the arc-shaped band disposed concentrically with a groove substantially parallel to the longitudinal direction. It is characterized by being unevenly distributed on the center side of the plate-like body.

  Also, one main surface of the plate-like body is used as a wafer mounting surface, and the other main surface of the plate-like body is provided with a belt-like resistance heating element, and the resistance heating element is arranged in an arc shape arranged substantially concentrically. It is composed of a band and a folded band connecting them, and has a groove substantially parallel to the longitudinal direction, and the groove formed in an arc-shaped band arranged concentrically is unevenly distributed on the outer peripheral side of the plate-like body It was made to be characterized.

  The groove may be a groove capable of adjusting a resistance value of the resistance heating element.

  Further, the distance between the pair of folded arc-shaped bands located on the same circumference of the resistance heating element is smaller than the distance between the arc-shaped bands disposed substantially concentrically at one place. Features.

  The distance between the pair of folded arc-shaped bands located on the same circumference of the resistance heating element is smaller than the distance between the arc-shaped bands disposed substantially concentrically at all locations. It is a characteristic.

  The distance between the pair of folded arc-shaped bands located on the same circumference of the resistance heating element is 30 to 80% of the distance between the arc-shaped bands disposed substantially concentrically. It is characterized by.

  In addition, the resistance heating element formed in a substantially concentric circle has a concentric circular outermost resistance heating element with a concentric circle of the resistance heating element excluding the outermost resistance heating element. It is characterized by being smaller than the interval between the strips.

  The groove may be a groove capable of adjusting a resistance value of the resistance heating element.

  The wafer heating apparatus of the present invention includes a resistance heating element zone having a power feeding part capable of independently heating the resistance heating element, and a metal case surrounding the power feeding part. It comprises a circular resistance heating element zone provided in the section and an annular resistance heating element zone surrounding the circular resistance heating element zone.

  As described above, the heater of the present invention and the heater for heating a wafer are provided with a strip-like resistance heating element on the surface of the plate-like body, the resistance heating element has a groove substantially parallel to the longitudinal direction, and the groove is formed on the plate. Due to the uneven distribution on the center side or the outer peripheral side of the body, rapid heating and forced cooling of the heater are repeated to prevent the progress of cracks generated in the width direction of the resistance heating element from the vicinity of the groove. Therefore, a serious failure such as disconnection of the resistance heating element can be prevented, and a change in the resistance value of the resistance heating element can be suppressed. Furthermore, since the resistance value of the resistance heating element is adjusted by arranging the grooves with good symmetry, the heating area of the resistance heating element can be maintained at a substantially uniform temperature. Furthermore, since the temperature difference in the wafer surface can be reduced by applying it to a wafer heating heater having a strip-like resistance heating element formed symmetrically with respect to the wafer, the temperature difference in the wafer surface is 0.3. It is possible to provide a heater for heating a wafer that is excellent in heat uniformity as small as below.

  In addition, it is possible to provide a heater with a good manufacturing yield of the heater, easy to mass-produce and inexpensive.

  Embodiments of the present invention will be described below.

  FIG. 1 is a cross-sectional view showing an example of a heater 1 according to the present invention, a wafer heating heater 110 manufactured using the heater 1, and a wafer heating device 111 using the wafer heating heater 110. One main surface of the plate-like body 2 is a wafer mounting surface 3 on which the wafer W is placed, and a resistance heating element 5 is formed on the other main surface, and gold or silver which can be electrically connected to the resistance heating element 5 When the resistance heating element 5 is provided with a plurality of grooves m and the resistance value is adjusted after the feeding portion 6 made of a material such as palladium or platinum is provided, the heater 110 for heating the wafer using the heater 1 can be manufactured.

  Next, the metal case 19 surrounding the power feeding unit 6 is fixed to the peripheral portion of the other main surface of the heater 1 through the connection member 17 so as not to directly contact the heater 1.

  Next, the bolt 16 is passed through the outer periphery in the vicinity of the opening of the metal case 19 and is elastically fixed by screwing the nut 20 through the elastic body 18 from the metal case 19 side. Thereby, even if the metal case 19 is deformed when the temperature of the heater 1 fluctuates, the deformation force is absorbed by the elastic body 18, thereby suppressing the warpage of the plate-like body 2, It is possible to prevent the occurrence of temperature variations due to warping of the body 2.

  Here, the metal case 19 has a bottom surface 21 and a side wall portion 22, and the plate-like body 2 is installed so as to cover the opening of the bottomed metal case 19. Further, the bottom surface 21 of the metal case 19 is provided with a gas injection port 24 for cooling the plate-like body 2 and a hole 23 for discharging the cooling gas, and a power supply unit for supplying power to the heater 1. When the power supply terminal 11 for conducting to 6 and the temperature measuring element 27 for measuring the temperature of the heater 1 are installed, the wafer heating apparatus 111 of the present invention can be manufactured.

  Then, lift pins 25 are provided through the through holes 26 penetrating the heater 1, and the lift pins 25 are lowered after the wafer W carried to the upper side of the mounting surface 3 by the transfer arm (not shown) is supported by the lift pins 25. The wafer W is then placed on the placement surface 3. Then, the power supply terminal 11 is connected to the power supply unit 6 and electric power is supplied from the outside, and the wafer W can be heated while the temperature measuring element 27 measures the temperature of the plate-like body 2.

  The wafer W is held in a state of being lifted from the mounting surface 3 by the wafer support pins 8 so as to prevent temperature variations caused by, for example, contact of the wafer W with one piece. Further, when the resistance heating element 5 is divided into a plurality of zones, the temperature of each zone is independently measured and each resistance heating element 5 is controlled to supply power to the power supply terminals 11 of each power supply unit 6. The power applied to the power supply terminal 11 is adjusted so that the temperature of each temperature measuring element 27 becomes each set value, so that the surface temperature of the wafer W placed on the mounting surface 3 becomes uniform.

  Then, after processing the wafer W, the wafer W can be lifted by the lift pins 25 through the guide member 10 and carried out by the transfer arm.

  FIG. 2A is a plan view showing an example of the heater 1 of the present invention, and a strip-like resistance heating element 5 formed by a screen printing method or the like is provided on one main surface of the plate-like body 2. .

  Here, the band formed of the resistance heating element 5 includes arc-shaped bands 5i, 5j, 5k, 5m, 5n, 5o, and 5p having substantially the same line width, and folded arc-shaped bands 5q, 5r that connect them. 5s, 5t, 5u, and 5v are continuously formed in a concentric shape, and the end portions of the arc-shaped bands 5i and 5j are used as the power feeding unit 6. Therefore, the arc-shaped band 5i and the arc-shaped band 5j, the arc-shaped band 5k and the arc-shaped band 5m, the arc-shaped band 5n and the arc-shaped band 5o, and the arc-shaped band 5p each constitute a circle. Since each circle is arranged concentrically, if the resistance heating element 5 is heated, the temperature distribution of the mounting surface 3 is distributed concentrically from the center toward the peripheral edge. Can do.

  Further, arc-shaped bands 5i and 5j adjacent to each other in the radial direction and arc-shaped bands 5k and 5m, arc-shaped bands 5k and 5m, arc-shaped bands 5n and 5o, and arc-shaped bands 5n and 5o Since the distances L4, L5, and Lr from the belt 5p are arranged at substantially equal intervals, the calorific value per unit volume in each of the arc-shaped belts 5i to 5p can be equalized. In the radial direction, heat generation unevenness in the radial direction can be suppressed.

  The heater 1 has a group g composed of a plurality of grooves m1, m2,... Substantially parallel to the longitudinal direction of the band of the resistance heating element 5 and the group g is formed at the center of the band width. Preferably there is. Here, the fact that the group g is at the center of the band of the resistance heating element 5 indicates that the center of the group g in the width direction is at the center of the band, and more specifically, the width direction of the group g. It is more preferable that the center of the region is in a range smaller than two regions at the center of the region obtained by dividing the belt into four equal parts in the width direction, that is, the central portion is 50%.

  Thus, by forming the groove m in at least a part of the resistance heating element 5, a resistance adjustment unit is provided, and by adjusting the heat generation amount of the resistance heating element 5, the temperature of the heater 1 is made uniform. It is also possible to reduce the in-plane temperature difference.

  In the cross-sectional view perpendicular to the longitudinal direction of the band of the resistance heating element 5, the sectional areas of the bands of the resistance heating element 5 on both sides of the band of the resistance heating element 5 divided by the group g are substantially equal. That is, the resistance values of the bands of the resistance heating elements 5 on both sides are substantially equal. For this reason, the heating amount of the resistance heating element 5 is approximately equal to the left and right in the width direction, and the width of the band of the resistance heating element 5 is adjusted even if the group g is formed to adjust the variation in the partial resistance value of the resistance heating element 5. The center line of the direction does not change greatly from the design position, and the heater 1 can be heated uniformly by adjusting the resistance by forming a groove in the designed resistance heating element 5 pattern. As the wafer heating heater 110, the temperature difference in the W plane can be reduced.

  On the other hand, when the center in the width direction of the group g is shifted from the center in the width direction of the resistance heating element 5 as shown in FIGS. That part is likely to generate heat. For this reason, the right and left heat generation balance is lost in the width direction of the band of the resistance heating element 5 and a temperature difference is generated in the width direction, so that the in-plane temperature difference of the wafer W may be increased.

  As shown in FIG. 2A, the heater 1 of the present invention includes a strip-like resistance heating element 5 on the surface of a plate-like body 2, and the resistance heating element 5 has a plurality of grooves m substantially parallel to the longitudinal direction. And the groove m is unevenly distributed on the center side of the plate-like body 2. Alternatively, as shown in FIG. 2 (b), the groove m is unevenly distributed on the outer peripheral side of the plate-like body 2. This is because when the groove m for adjusting the resistance value is provided in an irregular place of the resistance heating element 5, the resistance heating element 5 is removed from the plate-like body 2 by rapidly heating the heater or repeating forced cooling. This is because peeling or the resistance value of the resistance heating element 5 tends to vary. This is because, in particular, cracks that occur in the width direction of the resistance heating element 5 travel and grow to the central portion of the resistance heating element 5 and the resistance heating element is disconnected, which may cause a serious failure of the heater 1. Furthermore, even if the resistance heating element 5 is disposed on the surface of the plate-like body 2 with good symmetry, the heating area of the resistance heating element 5 is likely to change slightly depending on the position of the groove m. The in-plane temperature difference may be increased.

  On the other hand, when the groove m formed in the resistance heating element 5 is formed so as to be unevenly distributed on the center side of the plate-like body 2 or unevenly distributed on the outer peripheral side, the progress of the crack is prevented and the variation of the resistance value is suppressed. In addition, since the grooves m can be arranged with good symmetry, the heating region of the resistance heating element 5 can be maintained at a substantially uniform temperature, and the temperature difference within the wafer W surface is within 0.3 ° C. Can be.

  Further, when heating the disk-shaped wafer, the plate-shaped body constituting the heater 1 is also formed in a disk shape, and in order to heat the wafer uniformly, it can be heated symmetrically with respect to the center of the wafer. In addition, it is preferable to form a resistance heating element on the plate-like body. This is because if the center symmetry with respect to the center of the wafer is lost, the heat difference to the container for housing the heater 1 and peripheral members cannot be adjusted, so that the temperature difference in the wafer surface may increase. Therefore, for the strip-shaped resistance heating element formed symmetrically with respect to the wafer, the groove formed in the belt is unevenly distributed on the outside of the belt or formed on the inside of the wafer. By making the calorific value of the resistance heating element 5 that heats the center symmetrical, the temperature difference in the wafer surface can be reduced. In order to effectively suppress the progress of the cracks, the grooves m may be formed in the band substantially equally on the center side and the outer peripheral side of the plate-like body 2.

  Here, when the groove m is unevenly distributed on the center side or the outer periphery side of the plate-like body 2, the groove m is provided closer to the center side than the center line in the longitudinal direction of the resistance heating element 5, or closer to the outer periphery side. This means that the groove m is provided. Further, if the width of the groove m is half or more of the width of the resistance heating element 5 (short direction), the groove m straddles the center line. In this case, the groove m on the resistance heating element 5 The direction that occupies a large area is the uneven distribution direction. Further, as will be described in detail below, even when the grooves m constitute the group G, the same idea may be taken.

  Further, it is preferable that the width of the band of the resistance heating element 5 is 0.5 to 8 mm in order to reduce the in-plane temperature difference of the wafer W. When the width of the band is 0.5 mm or less, it is not preferable to form by a printing method because the line width is too small and bleeding occurs. On the other hand, if the thickness exceeds 8 mm, the amount of heat generated varies greatly between the inner and outer circumferences of the curved portion of the band, and it is difficult to generate heat uniformly. More preferably, it is 1-4 mm.

  Further, as shown in FIG. 3, it is preferable that a plurality of grooves m are provided substantially in parallel with the longitudinal direction of the belt, and a group G1 including a plurality of grooves m1, m2,. This is because the width of the groove m is as small as several tens of μm for such a band and the depth is as small as about 20 to 80% of the thickness of the band, so that the resistance value of the section can be adjusted with a single groove. The amount is about 0.025 to 1.6%. Therefore, by providing a plurality of these grooves m substantially parallel to the longitudinal direction of the band and having a group G1 composed of a plurality of grooves m1, m2,... Adjacent to each other, the resistance value of each section can be adjusted with high accuracy. In addition, even if resistance variation of about 10% occurs in each section, the resistance value can be adjusted to a predetermined value by forming a plurality of grooves m.

  Further, as shown in FIG. 3, the groups G1 to G3 are divided into a plurality along the longitudinal direction of the band of the resistance heating element 5, and the interval Gg between the group G1 and the group G2 is the width Wh of the band. Preferably it is smaller. This is because if the gap Gg is larger than the width Wh of the band, the resistance is reduced at this portion, and the amount of heat generation is reduced, so that a cool spot may be formed. If the interval Gg is not provided, the length of one group G increases, so that a slight positional deviation increases as shown in FIG. And even if it matches with the center at the start point P1, the group G is formed at the position deviated from the center of the band width at the end point P2. Therefore, the cross-sectional areas serving as current paths are greatly different on the left and right of the cross section of the resistance heating element 5 adjacent to the end point P2 of the group G, and the amount of heat generation is different on the left and right of the band in the cross section of the band of the resistance heating element 5. There is a risk that the in-plane temperature difference becomes large.

  Moreover, it is preferable that the length of the said group G is 30 to 97% of the total length of the centerline of one said band in which each group G is formed. This is because it is difficult to adjust the thickness variation of the band produced by the screen printing method with the groove m or the group G if the total length of the projection line in the length direction of the band of the groove m or the group G is less than 30%. If it exceeds 97%, it is difficult to produce a groove formed in the curved portion of the band, which is not practical. Preferably it is 60 to 90%, More preferably, it is 70 to 85%.

  The belt is composed of arc-shaped belts 5i to 5p arranged substantially concentrically and folded arc-shaped belts 5q to 5v connecting them, and a pair of belts located on the same circumference at least at one place. The distance Lm between the folded arcuate bands 5u to 5v is preferably smaller than the distance Lr between the arcuate bands 5n to 5p and 5o to 5p.

  This is because when the distance Lm is larger than the distance Lr, the heat generation density of the gap portion Q around the folded portion between the arc-shaped bands 5n to 5p and the folded arc-shaped bands 5u to 5v becomes small. This is because the in-plane temperature difference of the wafer W becomes large and the heat uniformity may be impaired.

  On the other hand, when the distance Lm is smaller than the distance Lr, the amount of heat generated in the gap Q is compensated by the heat generated from the opposed arcuate bands 5u to 5v, and the temperature drop in the gap Q is suppressed. Therefore, the in-plane temperature difference of the wafer W placed on the placement surface 3 can be reduced, and the thermal uniformity can be improved.

  Further, arc-shaped bands in which the distances L1, L2, and Lm between the pair of folded arc-shaped bands 5q to 5v located on the same circumference of the resistance heating element 5 are arranged substantially concentrically at all points. More preferably, it is smaller than the distances L4, L5 and Lr between 5i and 5p.

  In particular, the distances L1, L2, and Lm between the pair of folded arc-shaped bands 5q to 5v located on the same circumference are distances L4 between the arc-shaped bands 5i to 5p disposed substantially concentrically. , L5, Lr 30 to 80%, more preferably 40 to 60%, it is possible to further improve the thermal uniformity on the mounting surface 3. The distances L1 to Lm are obtained by measuring the distance between the resistance heating elements 5 at several locations and calculating the average distance.

  In addition, the resistance heating element 5 formed in a substantially concentric shape has an interval Lr between the outermost resistance heating element band 5p and the inner bands 5o, 5n of the concentric circular outer resistance heating element. It is preferable that the distance between the concentric strips L5 and L4 of the resistance heating element to be removed is smaller. The peripheral part of the heater 1 is easily deprived of heat by radiating heat or convection to the peripheral part, and the temperature of the peripheral part of the heater 1 may be lowered. This is because the amount of heat generated in the peripheral portion can be increased by reducing the distance Lr between the bands 5o and 5n. This is because when the object to be heated is placed on the heater 1 and heated, the surface of the object to be heated can be heated uniformly.

  Further, the heater 111 for heating a wafer according to the present invention has one main surface of the plate-like body 2 as a wafer mounting surface 3, and the other main surface of the plate-like body 2 includes a strip-like resistance heating element 5, The resistance heating element 5 includes arc-shaped bands 5i to 5p arranged substantially concentrically and folded bands 5q to 5v connecting them, and has a groove m substantially parallel to the longitudinal direction, and is arranged concentrically. The groove m formed in the arc-shaped bands 5i to 5p to be provided is unevenly distributed on the center side of the plate-like body 2. This is because it is important that the arc-shaped strips arranged substantially concentrically around the center of the plate-like body 2 generate heat symmetrically with respect to the center of the plate-like body 2 and are arranged concentrically. The arcs 5i to 5p of the grooves m are unevenly distributed on the center side, so that the heater is rapidly heated, or the resistance heating element 5 is peeled off from the plate-like body 2 by repeating forced cooling, Variations in the resistance value of the resistance heating element 5 can be suppressed. Further, the rapid heating and forced cooling of the heater can be repeated to prevent the progress of cracks generated in the width direction of the resistance heating element from the vicinity of the groove, so that a serious failure can be avoided. Furthermore, since the grooves m can be arranged with good symmetry, it is possible to maintain the heat generating area of the resistance heating element 5 at a substantially uniform temperature, and the temperature difference in the wafer W plane is within 0.3 ° C. Can be small. Note that the arc-shaped bands 5i to 5p arranged substantially concentrically and the folded bands 5q to 5u connecting them may be arc-shaped as shown in FIG. 2 or linear (not shown).

  Similarly, one main surface of the plate-like body 2 is a wafer mounting surface 3, and the other main surface of the plate-like body 2 is provided with a strip-like resistance heating element 5, and the resistance heating element 5 is substantially concentric. Arc-shaped bands 5i to 5p arranged on the inner side and folded bands 5q to 5v connecting them, and having grooves m substantially parallel to the longitudinal direction, and arranged in a concentric manner. The groove m formed in 5p is unevenly distributed on the outer peripheral side of the plate-like body 2. By making the groove m unevenly distributed on the outer peripheral side in this way, the progress of cracks can be prevented and the temperature difference in the wafer W plane can be reduced, as in the case where the groove m described above is unevenly distributed on the center side of the plate-like body. Can do. It should be noted that, in the band of one resistance heating element 5 arranged substantially concentrically, thermal expansion occurs at the boundary line between the plate-like body 2 and the heating resistance 5 on the projection surface obtained by projecting the resistance heating element 5 onto the plate-like body 2. Due to this, cracks extending from the outer boundary line of the resistance heating element 5 to the center side of the plate-like body through the inside of the band are likely to occur in the resistance heating element 5, but the groove is unevenly distributed on the outer peripheral side. In this case, since the extension of cracks can be suppressed by this groove, the resistance change of the resistance heating element can be suppressed to a small value and the effect of preventing disconnection of the resistance heating element is great. Therefore, it is more preferable that the groove is unevenly distributed on the outer peripheral side.

  The groove m is preferably a groove m capable of adjusting the resistance value of the resistance heating element 5.

Here, the groove m can be formed by melting and removing the resistance heating element 5 formed of a conductive material made of a noble metal and a glassy binder with a laser beam. In addition, a laser beam is preferable because it is easy to accurately form the narrow groove m. The size of the laser beam is preferably 5 to 100 μm, more preferably 30 to 80 μm, and still more preferably 50 to 70 μm. The groove m is formed by a laser beam or the like, but the size of the groove m is determined by the output of the laser beam and the irradiation time, and since the output and the irradiation time are not normally changed during processing of the groove m, the depth of the groove m is It is almost equivalent. Therefore, when the groove m is formed in a location within 90% of the width of the band of the resistance heating element 5 excluding the region having a small thickness at the peripheral portion, there is no possibility that the groove m penetrates the resistance heating element 5, and the groove m The possibility of generating cracks at the bottom is small and preferable. However, when the groove m is formed so as to exceed 90% of the width of the band of the resistance heating element 5, the groove m is formed in a portion where the film thickness at both ends of the resistance heating element 5 is thin. There is a possibility that microcracks may be caused by penetrating 5 or irradiating the plate-like body 2 with a laser beam.

  Further, as shown in FIG. 5, the distances Lm and Lm2 between the pair of folded arc-shaped strips located on the same circumference of the resistance heating element 5 are arranged in a substantially concentric circle at least at one place. It is preferable to be smaller than the distances Lr and Lr2 between the bands. If the distances Lm and Lm2 are smaller than the distances Lr and Lr2, the temperature drop in the vicinity of Lm, for example, at the Q position can be prevented, so that the temperature difference in the wafer surface can be reduced.

Further, a distance Lm between a pair of folded arc-shaped bands located on the same circumference of the resistance heating element, Lm2 is a distance Lr between arc-shaped bands disposed substantially concentrically at all locations, It is preferably smaller than Lr2. Thus, it is preferable that the distances Lm and Lm2 are smaller than the distances Lr and Lr2 corresponding to the distances, respectively, because variations in temperature difference are reduced in all surface areas of the wafer.

  The distances Lm and Lm2 between the pair of folded arc-shaped bands located on the same circumference are 30 to 80% of the distances Lr and Lr2 between the arc-shaped bands disposed substantially concentrically. More preferably, if it is 40 to 60%, the thermal uniformity on the mounting surface 3 can be further enhanced. The distances L1 to Lm are obtained by measuring the distance between the resistance heating elements 5 at several locations and calculating the average distance.

  Further, the resistance heating element 5 formed in a substantially concentric shape has a distance Lr between a concentric outermost resistance heating element band and an inner band of the resistance heating element excluding the outermost resistance heating element. It is preferable that the distance between the concentric strips L4, Lr5 and Lr2 is smaller. The peripheral portion of the wafer heating heater 110 is easily deprived of heat by radiating heat or convection to the peripheral portion, and the temperature of the peripheral portion of the wafer heating heater 110 may be lowered. This is because the amount of heat generated in the peripheral portion can be increased by reducing the distance Lr between the band 5p and the inner bands 5o, 5n. This is because when the wafer is placed on the placement surface 3 and heated, the inside of the wafer can be heated uniformly.

  Having described the features of the present invention, other related configurations will be described.

  The width Wg of the group G is preferably within 90% of the width Wh of the band of the resistance heating element 5. This is because the fine and complicated resistance heating element 5 is usually formed by the screen printing method, so that the cross-sectional area of the resistance heating element 5 formed by the screen printing method is the band of the resistance heating element 5 as shown in FIG. This is because the thickness of the region 5% left and right of the width is small. The groove m is formed by a laser beam or the like. The size of the groove m is determined by the output of the laser beam and the irradiation time, and the output and irradiation time are not changed during processing of the normal groove m. This is almost the same. Therefore, when the groove m is formed in a location within 90% of the width of the band of the resistance heating element 5 excluding the region having a small thickness at the peripheral portion, there is no possibility that the groove m penetrates the resistance heating element 5, and the groove m The possibility of generating cracks at the bottom is small and preferable. However, when the groove m is formed so as to exceed 90% of the width of the band of the resistance heating element 5, the groove m is formed in a portion where the film thickness at both ends of the resistance heating element 5 is thin. This is because there is a possibility that micro cracks may be caused by penetrating 5 or irradiating the plate-like body 2 with a laser beam.

  Further, the depth of each of the grooves m1, m2,... Constituting the group G of the grooves m is preferably in the range of 20 to 75% of the width Wm of the grooves m (groove depth / groove width = 20 to 75%). This is because if it is less than 20%, the change in resistance value due to the formation of one groove m is small and the adjustment range of the resistance value is also small, so it becomes difficult to sufficiently reduce the in-plane temperature difference of the wafer W. It is.

  Further, when the depth of the groove m exceeds 75% of the width Wm, the energy of the first pulse of the laser is large and microcracks are generated at the bottom of the resistance heating element 5, and microcracks grow when heating and cooling are repeated. This is because a change in the resistance value of the resistance heating element 5 occurs, and if the resistance value changes, the in-plane temperature difference of the wafer W becomes large and it may not be possible to maintain the thermal uniformity.

  In addition, since laser trimming is normally performed in the atmosphere, the main component is Pt, Au, or an alloy thereof, which is a noble metal having good heat resistance and oxidation resistance, as a conduction component contained in the resistance heating element 5. Is preferably used. As the resistance heating element 5, it is preferable to mix 30 to 70% by weight of a glass component in order to improve adhesion to the insulating layer and sinterability of the resistance heating element itself.

  As an example of the pattern shape of the resistance heating element 5, as shown in FIG. 4A, a zone (hereinafter referred to as resistance) consisting of a plurality of concentric and annular resistance heating elements 5 located on the outer peripheral portion of the plate-like body 2. A heating element zone) and a resistance heating element zone comprising a concentric resistance heating element 5 in the center. Further, in FIG. 4B, the resistance heating element 5 is divided so that a total of eight resistance heating element zones comprising four zones at the outer peripheral portion of the plate-like body 2 and four zones at the central portion are formed. ing. In addition, since each resistance heating element zone has the electric power feeding part 6, each resistance heating element zone can be heated independently. FIG. 5 shows an example of a wafer heating heater comprising four resistance heating element zones.

  FIG. 4A includes a plurality of resistance heating element zones 4 on one main surface of the plate-like body 2, and a circular resistance heating element zone 4 a at the center and three concentric rings on the outer side thereof. Resistance heating element zones 4b, 4c, and 4d are provided. This is to improve the thermal uniformity of the wafer W by dividing the resistance heating element 5 corresponding to the four resistance heating element zones.

  Further, the outer diameter D1 of the resistance heating element zone 4a located at the center of the plate-like body 2 is 20 to 40% of the outer diameter D of the resistance heating element zone 4d at the outermost peripheral part, outside the resistance heating element zone 4a. The outer diameter D2 of a certain resistance heating element zone 4b is 40 to 55% of the outer diameter D, and the outer diameter D3 of the resistance heating element zone 4c outside the resistance heating element zone 4b is 55 to 85% of the outer diameter D. This is preferable because the in-plane temperature difference of the wafer W can be reduced.

  More preferably, the outer diameter D1 is 23 to 33% of the outer diameter D of the resistance heating element zone 4d at the outermost periphery, and the outer diameter D2 of the resistance heating element zone 4b outside the resistance heating element zone 4a is the outer diameter D. Further, the outer diameter D3 of the resistance heating element zone 4c outside the resistance heating element zone 4b is 63 to 83% of the outer diameter D, thereby further reducing the in-plane temperature difference of the wafer W. This is preferable.

  The outer diameter D of the outermost resistance heating element zone 4d is a circumscribed circle surrounding the resistance heating element constituting the resistance heating element zone 4d when viewed from a projection plane parallel to the other main surface of the plate-like body 2. Is the diameter. The circumscribed circle can be obtained along a concentric circular arc except for the protruding portion of the resistance heating element 5 connected to the power feeding unit 6.

  Here, if the outer diameter D1 is less than 20% of D, the outer diameter of the resistance heating element zone 4a at the center is too small. Therefore, even if the heating value of the resistance heating element zone 4a is increased, the center of the resistance heating element zone 4a is increased. There is a possibility that the temperature of the central part does not rise and the temperature of the central part decreases. Further, if the outer diameter D1 exceeds 40%, the outer diameter of the resistance heating element zone 4a at the center is too large, so when the temperature at the center is increased, the temperature at the periphery of the resistance heating element zone 4a also increases. This is because the temperature around the resistance heating element zone 4a may become too high. Preferably, the outer diameter D1 is 20 to 35% of D, and more preferably the outer diameter D1 is 23 to 33% of D, so that the in-plane temperature difference of the wafer W can be further reduced. .

  Further, when the outer diameter D2 is less than 40% of the outer diameter D, the peripheral portion of the heater 1 is easily cooled. Therefore, when the amount of heat generated in the resistance heating element zone 4c is increased in order to prevent a decrease in the temperature around the wafer W. In addition, the temperature inside the resistance heating element zone 4c close to the center of the wafer W may be increased, and the in-plane temperature difference of the wafer W may be increased. When the outer diameter D2 exceeds 55% of the outer diameter D, the temperature of the resistance heating element zone 4cd increases even if the heating value of the resistance heating element zone 4c is increased in order to prevent the temperature around the wafer W from decreasing. There is a risk that the temperature decrease around the wafer W reaches the resistance heating element zone 4b, and the temperature outside the resistance heating element zone 4b is lowered. Preferably, when the outer diameter D2 is 41 to 55% of the outer diameter D, and more preferably 45 to 55%, the in-plane temperature difference of the wafer W can be further reduced.

  Further, when the outer diameter D3 is less than 55% of the outer diameter D, the peripheral portion of the heater 1 is easily cooled. Therefore, when the amount of heat generated in the resistance heating element zone 4d is increased in order to prevent the temperature around the wafer W from being lowered, There is a possibility that the temperature inside the resistance heating element zone 4d close to the center of the wafer W becomes high and the in-plane temperature difference of the wafer W becomes large. When the outer diameter D3 exceeds 85% of the outer diameter D, the temperature of the resistance heating element zone 4eh increases even if the heating value of the resistance heating element zone 4d is increased so as to prevent the temperature around the wafer W from being lowered. However, there is a possibility that the temperature decrease around the wafer W reaches the resistance heating element zone 4c and the temperature outside the resistance heating element zone 4c is lowered. Preferably, when the outer diameter D3 is 60 to 85% of the outer diameter D, and more preferably 63 to 83%, the in-plane temperature difference of the wafer W can be further reduced.

  Further, FIG. 4 (b) shows that among the three annular resistance heating element zones 4b, 4c, 4d, the innermost resistance heating element zone 4b is a resistance heating element zone 4b formed of an annular shape, and the outer side thereof. The resistance heating element zone 4c is two fan-like resistance heating element zones 4c1 and 4c2 obtained by dividing the ring into two in the circumferential direction, and the outer resistance heating element zone 4d is arranged in the circumferential direction. In order to make the surface temperature of the wafer W uniform, it is preferably composed of four fan-like resistance heating element zones 4d1, 4d2, 4d3 and 4d4.

  The annular resistance heating element zones 4c and 4d are divided into two and four in the radial direction, respectively, but the invention is not limited to this.

  According to FIG. 4B, the boundary lines dividing the resistance heating element zones 4c and 4d are straight lines, but they are not necessarily straight lines, and may be wavy lines. It is preferably centrosymmetric with respect to the center of the concentric heating element zone.

  It is preferable that each of the resistance heating elements 5 is manufactured by a printing method or the like, and the band of the resistance heating element 5 is formed with a width of 1 to 5 mm and a thickness of 5 to 50 μm. When the printing surface to be printed at one time becomes large, there is a concern that the printing thickness may not be constant due to the difference in pressure between the squeegee and the screen on the left and right or front and back of the printing surface. In particular, when the size of the resistance heating element 5 is increased, the thickness of the resistance heating element 5 on the left and right sides is different, and the designed heat generation may vary. If the amount of generated heat varies, the in-plane temperature difference of the wafer W increases, which is not preferable. In order to prevent the temperature variation resulting from the variation in thickness of the resistance heating element, it can be reduced by dividing each resistance heating element 5 having a large outer diameter, which is composed of one resistance heating element.

  As shown in FIG. 5, at least one of the plurality of strip-like resistance heating elements 5a, 5b, 5c, 5d, 5e, 5f, 5g, and 5h that can be heated independently is located on the same circumference. The distance between the pair of folded arc-shaped bands is preferably smaller than the distance between the bands of the resistance heating element 5. Thereby, since the temperature fall in the space | gap part Q periphery can be suppressed, the temperature difference in the wafer W surface can be made small.

  Further, in all of the plurality of resistance heating elements 5a, 5b, 5c, 5d, 5e, 5f, 5g, and 5h, an arc-shaped band positioned on the same circumference and a folded arc-shaped band that connects them. In addition, the distance between the pair of folded arc-shaped bands located on the same circumference is smaller than the distance between the arc-shaped bands, in order to reduce the temperature difference in the wafer W plane. preferable.

  Further, the resistance heating element 5 is composed of a plurality of heating elements that can be heated concentrically independently, and the distance between the outermost resistance heating element strip in the concentric circle and the inner band is independent of the outermost periphery. It is preferable that it is smaller than the interval between the concentric bands of the resistance heating element excluding the resistance heating element. By adopting such a configuration, the amount of heat generated in the peripheral portion of the plate-like body 2 can be increased, and therefore, a temperature drop in the peripheral portion of the wafer W due to thermal shrinkage in the peripheral portion can be prevented.

  In addition, it is preferable that the diameter D of the circumscribed circle C of the resistance heating element 5 closest to the outer periphery of the plate-like body 2 is 90 to 97% of the diameter DP of the plate-like body 2. This is because if the diameter D of the circumscribed circle C of the resistance heating element 5 is smaller than 90% of the diameter DP of the plate-like body 2, the time for rapidly raising or lowering the temperature of the wafer W increases and the temperature of the wafer W increases. Response characteristics are inferior. In order to uniformly heat the surface temperature of the wafer W so as not to lower the temperature at the periphery of the wafer W, the diameter D is preferably about 1.02 times the diameter of the wafer W. On the other hand, the diameter DP of the plate-like body 2 is increased, and the size of the wafer W that can be uniformly heated is smaller than the diameter DP of the plate-like body 2, and the wafer W is heated with respect to the input power for heating the wafer W. Heating efficiency is reduced. Furthermore, since the plate-like body 2 becomes large, the installation area of the wafer manufacturing apparatus becomes large, which is not preferable because the operation rate with respect to the installation area of the semiconductor manufacturing apparatus that needs to perform the maximum production with the minimum installation area is lowered.

  On the other hand, if the diameter D of the circumscribed circle C of the resistance heating element 5 is larger than 97% of the diameter DP of the plate-like body 2, the distance between the contact member 17 and the outer periphery of the resistance heating element 5 is small. Heat flows unevenly from the contact member 17 to the contact member 17. In particular, heat flows from a portion where the arc-shaped resistance heating element zone 51 in contact with the outer circumscribed circle C does not exist, and the arc-shaped resistance heating element zone 51 on the outer periphery is formed. Since the bent portion 2 is bent toward the center of the plate-like body 2, the temperature of the gap Q where the arc-shaped resistance heating element zone 51 is missing decreases along the circumscribed circle C surrounding the resistance heating element 5, and the in-plane temperature difference of the wafer W is reduced. May increase. More preferably, the diameter D of the circumscribed circle C of the resistance heating element 5 is 92 to 95% of the diameter DP of the plate-like body 2.

  The distance Lm between the folded arc-shaped bands of the resistance heating elements 5e, 5f, 5g, and 5h located closest to the outer periphery of the plate-like body 2 is the diameter DP of the plate-like body 2 and the diameter of the circumscribed circle C. It is preferably smaller than the difference from D (hereinafter abbreviated as LL). If the distance L10 is larger than LL, the heat of the gap portion Q flows to the peripheral portion of the plate-like body 2 and the temperature of the gap portion Q may be lowered. However, if the distance L10 is smaller than LL, the temperature of the gap Q is difficult to decrease, and the temperature of a part of the periphery of the wafer W placed on the mounting surface 3 of the plate-like body 2 does not decrease, and the temperature difference within the wafer W surface. Is preferable.

  In addition, in the heater 1 in which the one main surface side of the plate-like body 2 having a plate thickness of 1 to 7 mm is used as the mounting surface 3 on which the wafer is placed, and the lower surface of the plate-like body 2 includes the resistance heating element 5. The resistance heating element 5 has a thickness of 5 to 50 μm, and the circumscribed circle C is surrounded by the area of the circumscribed circle C surrounding the resistance heating element 5 when viewed in a projection plane parallel to the main surface of the plate-like body 2. The area ratio of the resistance heating element 5 to the circle C is preferably 5 to 30%. When the ratio of the area of the resistance heating element 5 in the circumscribed circle C to the area of the circumscribed circle C surrounding the resistance heating element 5 is less than 5%, the band of the pair of folded arc resistance heating elements 5 is formed. Since the distances Lm, L1,... Between them become too large, the surface temperature of the mounting surface 3 corresponding to the gap portion Q becomes smaller than the other portions, and the temperature of the mounting surface 3 is made uniform. It becomes difficult to do.

When the ratio of the area of the resistance heating element 5 in the circumscribed circle C to the area of the circumscribed circle C surrounding the resistance heating element 5 exceeds 30%, the space between the plate-like body 2 and the resistance heating element 5 is increased. Even when the thermal expansion difference is approximated to 2.0 × 10 ⁻⁶ / ° C. or less, the thermal stress acting between the two is too large, so that the plate-like body 2 is hardly deformed, but the plate thickness is 1 to 1 If the resistance heating element 5 is heated because it is as thin as 7 mm, the plate-like body 2 may be warped so that the mounting surface 3 side is concave. As a result, the temperature of the central portion of the wafer W becomes lower than the peripheral edge, and there is a possibility that the temperature variation becomes large.

  The ratio of the area of the resistance heating element 5 in the circumscribed circle C to the area of the circumscribed circle C surrounding the resistance heating element 5 is preferably 7 to 20%, more preferably 8 to 15%. .

  More specifically, the distance L1 is preferably 0.5 mm or more and 3 times or less the plate thickness of the plate-like body 2. When the distance L1 is 0.5 mm or less, when the resistance heating element 5 is printed and formed, a whisker-like protrusion may be generated in the opposing region of the resistance heating element 5 and the portion may be short-circuited. Further, if the distance L1 exceeds three times the thickness of the plate-like body 2, a cool spot may be generated on the surface of the wafer W corresponding to the distance L1, and the in-plane temperature difference of the wafer W may be increased.

  Furthermore, in order to efficiently exhibit such an effect, the thickness of the resistance heating element 5 is preferably set to 5 to 50 μm. This is because if the thickness of the resistance heating element 5 is less than 5 μm, it is difficult to print the resistance heating element 5 uniformly by screen printing. If it exceeds 50 μm, even if the ratio of the area occupied by the resistance heating element 5 to the circumscribed circle C is 30% or less, the thickness of the resistance heating element 5 is increased, the rigidity of the resistance heating element 5 is increased, and the plate-like ceramic body 5 There is a possibility that the plate-like body 2 is deformed due to the influence of expansion and contraction of the resistance heating element 5 due to the temperature change. Preferably, the thickness of the resistance heating element 5 is 10 to 30 μm.

  Hereinafter, members used for the heater, the wafer heating heater, and the wafer heating apparatus of the present invention will be described.

  As the material of the plate-like body 2, alumina, silicon nitride, sialon, aluminum nitride and silicon carbide having a Young's modulus at 100 to 200 ° C. of about 200 to 450 MPa can be used. m · K) or higher, more preferably 100 W / (m · K) or higher, and excellent corrosion resistance and plasma resistance against corrosive gases such as fluorine and chlorine. .

  In addition, the plate-like body 2 can use a metal plate instead of the ceramic material. As the material of the metal plate, tungsten, molybdenum, Fe—Ni—Co alloy, SUS, or the like can be used. However, for a metal material having a small Young's modulus, it is preferable that the plate-like body 2 is provided with a reinforcing member, or the plate-like body 2 is thicker than the ceramic plate-like body 2.

  On the other hand, when the heater 1 is used for forming a resist film, if the main component of the plate-like body 2 is made of silicon carbide, it does not react with moisture in the atmosphere and does not generate gas. Even if it is used for applying a resist film to the substrate, fine wirings can be formed at a high density without adversely affecting the structure of the resist film. At this time, it is necessary that the sintering aid does not contain nitrides that may react with water to form ammonia or amines.

When the silicon carbide sintered body is formed as the plate-like body 2, boron (B) and carbon (C) are added as sintering aids to the main component silicon carbide, or alumina (Al ₂ It can be obtained by adding a metal oxide such as O ₃ ) yttria (Y ₂ O ₃ ), mixing it well, processing it into a flat plate, and firing it at 1900-2100 ° C. Silicon carbide may be either mainly α-type or β-type.

  At this time, as the insulating layer for maintaining insulation between the plate-like body 2 and the resistance heating element 5, glass or resin can be used. When glass is used, the withstand voltage is 1 when the thickness is less than 100 μm. If the insulation is not maintained below 0.5 kV and the thickness exceeds 400 μm, the thermal expansion difference from the silicon carbide sintered body forming the plate-like body 2 becomes too large, and cracks are generated. It will not function as an insulating layer. Therefore, when glass is used as the insulating layer, the thickness of the insulating layer 4 is preferably formed in the range of 100 to 400 μm, and more preferably in the range of 200 to 350 μm.

  Furthermore, the main surface opposite to the mounting surface 3 of the plate-like body 2 has a flatness of 20 μm or less and a surface roughness with a centerline average roughness from the viewpoint of improving the adhesion with the insulating layer 4 made of glass or resin. It is preferable to polish it to 0.1 to 0.5 μm with (Ra).

Further, when the plate-like body 2 is formed of a sintered body containing aluminum nitride as a main component, a rare earth element such as Y ₂ O ₃ or Yb ₂ O ₃ as a sintering aid with respect to the main component aluminum nitride. It is obtained by adding an oxide and an alkaline earth metal oxide such as CaO as necessary and mixing them well, processing them into a flat plate, and then firing at 1900 to 2100 ° C. in nitrogen gas. In order to improve the adhesion of the resistance heating element 5 to the plate-like body 2, an insulating layer made of glass may be formed. However, when sufficient glass is added in the resistance heating element 5 and sufficient adhesion strength can be obtained by this, it can be omitted.

  The thickness of the plate-like body 2 is preferably 2 to 5 mm. When the thickness of the plate-like body 2 is less than 2 mm, the strength of the plate-like body 2 is lost, and when the cooling air from the gas injection port 24 is blown when the resistance heating element 5 is heated by heat generation, It is because it cannot endure and there exists a possibility that the crack may generate | occur | produce in the plate-shaped body 2. FIG. On the other hand, if the thickness of the plate-like body 2 exceeds 5 mm, the heat capacity of the plate-like body 2 increases, so that there is a possibility that the time until the temperature during heating and cooling becomes stable becomes longer.

The glass forming the insulating layer may be crystalline or amorphous, and the thermal expansion coefficient in the temperature range of 200 ° C. or higher and 0 to 200 ° C. constitutes the plate-like body 2. It is preferable to appropriately select and use a ceramic having a thermal expansion coefficient in the range of −5 to + 5 × 10 ⁻⁷ / ° C. That is, if a glass having a thermal expansion coefficient outside the above range is used, the difference in thermal expansion from the ceramic forming the plate-like body 2 becomes too large, so that there are defects such as cracks and peeling during cooling after baking the glass. It is because it is easy to occur.

  In addition, as means for depositing an insulating layer made of glass on the plate-like body 2, an appropriate amount of the glass paste is dropped on the center of the plate-like body 2 and stretched by a spin coating method, or applied uniformly. After applying uniformly by a screen printing method, dipping method, spray coating method or the like, the glass paste may be baked at a temperature of 600 ° C. or higher. Moreover, when using glass as an insulating layer, the plate-like body 2 made of a silicon carbide sintered body or an aluminum nitride sintered body is heated to a temperature of about 850 to 1300 ° C. in advance, and the surface on which the insulating layer is deposited is formed. By performing the oxidation treatment, the adhesion with the insulating layer made of glass can be enhanced.

  The resistance heating element zone shape of the resistance heating element 5 of the present invention is divided into a plurality of blocks as shown in FIG. 4, and each block is composed of an arc-shaped resistance heating element zone and a linear resistance heating element zone. Since the heater 1 of the present invention is important to uniformly heat the wafer W, these resistance heating element zone shapes are the parts of the belt-like resistance heating element 5. It is preferable that the density is uniform.

  Further, when the resistance heating element 5 is divided into a plurality of blocks, it is preferable to uniformly heat the wafer W on the mounting surface 3 by independently controlling the temperature of each block.

The resistance heating element 5 is obtained by printing and baking an electrode paste containing glass frit or metal oxide on conductive metal particles on the plate-like body 2 by a printing method. As the metal particles, Au having a relatively low electrical resistance is used. , Ag, Cu, Pd, Pt, Rh are preferably used, and the glass frit is made of an oxide containing B, Si, Zn, and is smaller than the thermal expansion coefficient of the plate-like body 4. It is preferable to use a low expansion glass having a size of 5 × 10 ⁻⁶ / ° C. or less, and it is preferable to use at least one selected from silicon oxide, boron oxide, alumina, and titania as the metal oxide.

The glass frit is made of an oxide containing B, Si, Zn, and the thermal expansion coefficient of the metal particles constituting the resistance heating element 5 is larger than the thermal expansion coefficient of the plate-like body 2. This is because it is preferable to use a low expansion glass having a thermal expansion coefficient of 4.5 × 10 ⁻⁶ / ° C. or less, which is smaller than the thermal expansion coefficient of the plate-like body 2, in order to bring the thermal expansion coefficient of .

  Further, as the metal oxide, at least one selected from silicon oxide, boron oxide, alumina, and titania is used because it has excellent adhesion to the metal particles in the resistance heating element 5 and has a coefficient of thermal expansion. This is because the thermal expansion coefficient is close to that of the plate-like body 2 and the adhesion to the plate-like body 2 is also excellent.

  However, if the content of the metal oxide exceeds 80% with respect to the resistance heating element 5, the adhesion with the plate-like body 2 is increased, but the resistance value of the resistance heating element 5 is not preferable. Therefore, the content of the metal oxide is preferably 60% or less.

The resistance heating element 5 made of conductive metal particles and glass frit or metal oxide preferably has a thermal expansion difference of 3.0 × 10 ⁻⁶ / ° C. or less with respect to the plate-like body 2. .

That is, it is difficult to make the difference in thermal expansion between the resistance heating element 5 and the plate-like body 2 0.1 × 10 ⁻⁶ / ° C. On the contrary, the difference in thermal expansion between the resistance heating element 5 and the plate-like body 2 is difficult. If the temperature exceeds 3.0 × 10 ⁻⁶ / ° C., when the resistance heating element 5 is heated, the mounting surface 3 side may be warped in a concave shape due to thermal stress acting between the resistance heating element 5 and the plate-like body 2. Because.

  The cross section of the ring-shaped contact member 17 may be either polygonal or circular. However, when the plate-like body 2 and the contact member 17 are in contact with each other in a plane, the width of the contact portion where the plate-like body 2 and the contact member 17 are in contact is as follows. If it is 0.1-13 mm, the amount of heat of the plate-like body 2 can be reduced to the bottomed metal case 19 via the contact member 17. And the temperature difference in the surface of the wafer W is small, and the wafer W can be heated uniformly. More preferably, it is 0.1-8 mm. If the width of the contact portion of the contact member 17 is 0.1 mm or less, the contact portion may be deformed when the contact member 17 is fixed in contact with the plate-like body 2, and the contact member may be damaged. When the width of the contact portion of the contact member 17 exceeds 13 mm, the heat of the plate-like body 2 flows to the contact member, the temperature of the peripheral portion of the plate-like body 2 is lowered, and the wafer W is heated uniformly. Becomes difficult. Preferably, the width of the contact portion between the contact member 17 and the plate-like body 2 is 0.1 to 8 mm, more preferably 0.1 to 2 mm.

  Further, the thermal conductivity of the contact member 17 is preferably smaller than the thermal conductivity of the plate-like body 2. If the thermal conductivity of the contact member 17 is smaller than the thermal conductivity of the plate-like body 2, the temperature distribution in the surface of the wafer W placed on the plate-like body 2 can be heated uniformly, and the temperature of the plate-like body 2 can be changed. When raising or lowering, the amount of heat transfer with the contact member 17 is small, and there is little thermal interference with the bottomed metal case 19, making it easy to change the temperature quickly.

  In the heater 1 in which the thermal conductivity of the contact member 17 is smaller than 10% of the thermal conductivity of the plate-like body 2, it is difficult for the heat of the plate-like body 2 to flow into the bottomed metal case 19. The heat of the metal case 19 increases due to heat transfer by atmospheric gas (here, air) or radiation heat transfer, and the effect is small.

  When the thermal conductivity of the contact member 17 is larger than the thermal conductivity of the plate-like body 2, the heat of the peripheral part of the plate-like body 2 flows to the bottomed metal case 19 through the contact member 17, While heating the metal case 19, the temperature of the peripheral part of the plate-shaped body 2 falls and the temperature difference in the wafer W surface becomes large, which is not preferable. In addition, since the bottomed metal case 19 is heated, even if it is attempted to cool the plate-like body 2 by injecting air from the gas injection port 24, the cooling time increases because the temperature of the bottomed metal case 19 is high. When heating to a constant temperature, there is a concern that the time until the temperature reaches a certain temperature may increase.

  On the other hand, as a material constituting the contact member 17, the Young's modulus of the contact member is preferably 1 GPa or more, and more preferably 10 GPa or more in order to hold a small contact portion. With such a Young's modulus, even if the width of the contact portion is as small as 0.1 to 8 mm and the plate-like body 2 is fixed to the bottomed metal case 19 with the bolt 16 via the contact member 17, the contact The member 17 is not deformed, and the plate-like body 2 can be held with high accuracy without being displaced or changing the parallelism.

  In addition, the precision which cannot be obtained with the contact member which consists of resin which added fluororesin and glass fiber like patent document 2 can be achieved.

  As the material of the contact member 17, metals such as carbon steel made of iron and carbon and special steel added with nickel, manganese, and chromium are preferable because of their large Young's modulus. Further, as the material having low thermal conductivity, so-called Kovar such as stainless steel or Fe—Ni—Co alloy is preferable, and the material of the contact member 17 may be selected so as to be smaller than the thermal conductivity of the plate-like body 2. preferable.

  Furthermore, since the contact portion between the contact member 17 and the plate-like body 2 is small, and the contact portion is small, there is no possibility of the contact portion being lost and particles are generated, so that the stable contact portion can be held. The cross-section of the contact member 17 cut along a plane perpendicular to the polygonal shape is preferably circular rather than polygonal. When a circular wire having a cross-sectional diameter of 1 mm or less is used as the contact member 17, the position of the plate-like body 2 and the bottomed metal case 19 is It is possible to raise and lower the temperature of the wafer W uniformly and quickly without changing.

  In addition, the depth of the bottomed metal case 19 is 10 to 50 mm, and the bottom surface 21 is desirably installed at a distance of 10 to 50 mm from the plate-like body 2. More preferably, it is 20-30 mm. This is because heat equalization of the mounting surface 3 is facilitated by radiant heat between the plate-like body 2 and the bottomed metal case 19, and at the same time, there is a heat insulating effect from the outside, so the temperature of the mounting surface 3 is constant. This is because the time until the temperature is uniform is shortened.

  Further, regarding the method of feeding power to the resistance heating element 5, the feeding terminal 11 installed on the bottomed metal case 19 is connected to the feeding part 6 formed on the surface of the plate-like body 2 by pressing it with a spring (not shown). Secure and supply power. This is because when the terminal portion made of metal is embedded in the plate-like body 2 having a thickness of 2 to 5 mm, the thermal uniformity is deteriorated due to the heat capacity of the terminal portion. Therefore, as in the present invention, by pressing the power supply terminal 11 with a spring to ensure electrical connection, the thermal stress due to the temperature difference between the plate-like body 2 and the bottomed metal case 19 is relaxed, Electrical continuity can be maintained with high reliability. Further, an elastic conductor may be inserted as an intermediate layer in order to prevent the contact from becoming a point contact. This intermediate layer is effective by simply inserting a foil-like sheet. And it is preferable that the diameter by the side of the electric power feeding part 6 of the electric power feeding terminal 11 shall be 1.5-5 mm.

  Further, the temperature of the plate-like body 2 is measured by a thermocouple 27 whose tip is embedded in the plate-like body 2. As the thermocouple 27, it is preferable to use a sheath-type thermocouple 27 having an outer diameter of 0.8 mm or less from the viewpoint of responsiveness and workability of holding. In order to improve the reliability of temperature measurement, it is preferable that the tip of the thermocouple 27 has a hole formed in the plate-like body 2 and is fixed to the inner wall surface of the hole by a fixing member installed therein. Similarly, it is also possible to perform temperature measurement by embedding a temperature measuring resistor such as a thermocouple of a wire or Pt.

  As shown in FIG. 1, a plurality of support pins 8 are provided on one main surface of the plate-like body 2 to hold the wafer W at a certain distance from the one main surface of the plate-like body 2. It doesn't matter if you do.

  1 shows the heater 1 having only the resistance heating element 5 on the other main surface 3 of the plate-like body 2. However, the present invention provides an electrostatic adsorption between the main surface 3 and the resistance heating element 5. Needless to say, the electrodes may be embedded for use in plasma generation.

  The wafer heating heater 110 of the present invention and the wafer heating apparatus 111 using the same were manufactured as follows.

  (Example 1) A silicon carbide sintered body having a thermal conductivity of 80 W / (m · K) is ground to produce a plurality of plate-shaped bodies having a plate thickness of 4 mm and an outer diameter of 230 mm, In order to deposit an insulating layer on one main surface of each plate-like body, a glass paste prepared by kneading ethyl cellulose as a binder and terpineol as an organic solvent with respect to glass powder is laid by a screen printing method, After drying the organic solvent by heating to 150 ° C., degreasing treatment was performed at 550 ° C. for 30 minutes, and baking was further performed at a temperature of 700 to 900 ° C. to form an insulating layer made of glass having a thickness of 200 μm. Next, in order to deposit a resistance heating element on the insulating layer, 20 wt% Au powder, 10 wt% Pt powder, and 70 wt% glass as a conductive material are printed in a predetermined amount of resistance heating element zone shape, The organic solvent was dried by heating to 150 ° C., degreased at 450 ° C. for 30 minutes, and then baked at a temperature of 500 to 700 ° C. to form a resistance heating element having a thickness of 50 μm. The resistance heating element is composed of an arc-shaped band and a folded arc connecting them, and has a configuration of eight resistance heating element zones in which the central portion and the outer peripheral portion of the plate-like body are divided into four in the circumferential direction.

  Then, each resistance heating element zone of the resistance heating element thus manufactured is divided into about 50 locations, and in order to eliminate the difference between the resistance value designed at each location and the actually measured resistance value, a plurality of laser beams are irradiated to irradiate a plurality of resistance heating element zones. A group of grooves was formed to adjust the resistance. The above-described adjustment of the resistance value was performed for a resistance smaller than the design value based on the maximum resistance value measured by measuring the resistance value of each resistance heating element zone.

  Here, as the formation position of the group G composed of a plurality of grooves m, the center side of the plate-like body 2 (sample No. 1) from the longitudinal center line of the resistance heating element and the longitudinal center line of the resistance heating element 5 Further, wafer heaters provided on the outer peripheral side (sample No. 2) of the plate-like body 2 were produced.

  Further, as a comparative example, a heater (sample No. 3) in which a group consisting of a plurality of grooves is randomly provided on the resistance heating element, such as the center side and the outer peripheral side, or the central portion of the resistance heating element is provided. Produced.

  As a method for forming the groove, a YAG laser manufactured by NEC was used. The laser beam was irradiated with a wavelength of 1.06 μm, a pulse frequency of 1 KHz, a laser output of 0.4 W, and a processing speed of 5 mm / sec.

  In addition, the width | variety of the groove | channel produced on the said conditions was about 50-60 micrometers, and the depth was about 20-25 micrometers. And the pitch which is the space | interval of the groove | channel formed in each group was about 65 micrometers, and the number of the largest groove | channels was 13.

  Then, the wafer heating heater 110 manufactured as described above was attached to a metal case, and a temperature measuring element, a power supply terminal, and the like were attached to manufacture a wafer heating apparatus 111.

Evaluation of the produced wafer heating apparatus was performed using a temperature measuring wafer having a diameter of 300 mm in which temperature measuring resistors were embedded in 29 locations. A power supply is attached to each wafer heating device, the temperature of the wafer W is raised from 25 ° C. to 200 ° C. in 5 minutes, the temperature of the wafer W is set to 200 ° C., the wafer W is removed, and a temperature measuring wafer W at room temperature is mounted. The time until the average temperature of the wafer W became constant in the range of 200 ° C. ± 0.5 ° C. was measured as a response time. Further, after the temperature cycle of 30 ° C. to 200 ° C. in 5 minutes and holding for 5 minutes and then cooling for 30 minutes is repeated 1000 cycles, the temperature is set from room temperature to 200 ° C. and the maximum value of the wafer temperature after 10 minutes The difference between the minimum values was measured as a temperature difference in the wafer W plane. The results are as shown in Table 1.

  As shown in Table 1, sample No. In the heater 3 for heating the wafer, since the group G consisting of the grooves m is randomly provided on the resistance heating element, cracks generated by the above temperature cycle grow, and the resistance value of the resistance heating element 5 slightly varies. At the same time, since the symmetry of the groove m with respect to the plate-like body 2 is deteriorated, a temperature difference is generated in the heat generation region of each resistance heating element, and the temperature difference in the wafer surface is increased to 0.38 ° C., so that the heat uniformity is deteriorated. .

  On the other hand, sample No. which is an embodiment of the present invention. The heaters for heating the wafers 1 and 2 are provided with the groove m on the resistance heating element 5 being unevenly distributed in one direction with respect to the center of the plate-like body. At the same time, the symmetry of the groove m with respect to the plate-like body 2 is good, and the temperature difference in the heat generation region of each resistance heating element 5 can be reduced, so that the temperature difference in the wafer surface can be reduced.

  (Example 2) In the same manner as in Example 1 described above, the band of the resistance heating element 5 is formed with a width of 1.5 mm, and a group G of a plurality of grooves m is formed on the center side of the plate-like body 2 by laser. An unevenly distributed resistance heating element 5 was formed.

  And the relationship between the space | interval of several groups G and the width | variety of the resistance heating element 5 was verified.

  The interval between the groups G described above can be indicated by the interval between the smallest group in each resistance heating element zone.

And the temperature difference in the wafer W surface was measured by the method similar to Example 1. FIG. The results are as shown in Table 2.

  As shown in Table 2, the sample No. 1 in which the gap between the groups G is larger than the width of the band made of the resistance heating element 5 is used. 24, it was difficult to make the temperature at the interval the same as the other portions, and the temperature difference in the wafer surface was slightly large at 0.26 ° C.

  In contrast, sample no. In Nos. 21 to 24, the gap between the groups G was smaller than the width of the band made of the resistance heating element 5, and therefore the temperature difference in the wafer plane could be further reduced.

  (Example 3) First, 1.0% by mass of yttrium oxide in terms of weight is added to aluminum nitride powder, and further, kneaded for 48 hours by a ball mill using isopropyl alcohol and urethane balls to obtain an aluminum nitride slurry. Produced.

  Next, the aluminum nitride slurry was passed through 200 mesh to remove urethane balls and ball mill wall debris, and then dried at 120 ° C. for 24 hours in an explosion-proof dryer.

  Next, an acrylic binder and a solvent were mixed into the obtained aluminum nitride powder to produce an aluminum nitride slip, and a plurality of aluminum nitride green sheets were produced by a doctor blade method.

  Then, a laminate was formed by laminating a plurality of obtained aluminum nitride green sheets.

  Thereafter, the laminate is degreased at a temperature of 500 ° C. for 5 hours in a non-oxidizing gas stream, and then fired at a temperature of 1900 ° C. for 5 hours in a non-oxidizing atmosphere to obtain various thermal conductivities. An aluminum nitride sintered body having this was manufactured.

  Then, the aluminum nitride sintered body is ground to produce a plurality of disk-shaped ceramic bodies having a disk thickness of 3 mm and a diameter of 330 mm, and three through holes are evenly formed on a concentric circle 60 mm from the center. Formed. The through-hole diameter was 4 mm.

  Next, in order to deposit the resistance heating element 5 on the surface of the plate-like body 2, a conductor paste prepared by kneading a glass paste to which Au powder, Pd powder and a binder having the same composition as described above are added as a conductive material is prepared. After printing in a predetermined pattern shape by screen printing, heating to 150 ° C. to dry the organic solvent, degreasing treatment at 550 ° C. for 30 minutes, and baking at 700 to 900 ° C. Thus, the resistance heating element 5 having a thickness of 50 μm was formed.

  As shown in FIG. 5, the resistance heating element 5 is printed in a pattern shape consisting of a resistance heating element 5 consisting of arc-shaped strips in a substantially concentric circular shape, and a folded arc-shaped strip connecting them, and the resistance value is A groove m for adjustment is provided so as to be unevenly distributed on the center side of the plate-like body 2.

  Further, as shown in FIG. 4, the arrangement of the resistance heating element zones that divide the resistance heating element 5 described above is arranged in a circular shape of 25% of the diameter D of the plate-like body 2 at the center of the plate-like body 2. A resistance heating element zone 4a is formed, an annular resistance heating element zone 4b is formed on the outer side thereof, and a 45% outer ring having an outer diameter D is divided on the outer side thereof into two resistance heating element zones 41c and 42c. In addition, a 70% outer diameter D ring was divided into four resistance heating element zones 41d, 42d, 43d, and 44d, for a total of eight resistance heating element zones, and a sample was prepared with an outer diameter D of 310 mm. did.

  After that, the heater 110 for heating the wafer was manufactured by brazing and fixing the feeding portion 6 to the resistance heating element 5. In this embodiment, the central resistance heating element zone and the outer annular resistance heating element zone are connected in parallel, and heating control is performed simultaneously.

  A distance Lm between a pair of folded arc-shaped bands located on the same circumference and a distance Lr between two arc-shaped bands connected to the folded arc-shaped band are expressed as Lm / Lr × 100%. The heater 1 having different ratios was produced.

  Thereafter, a heater 110 for heating the wafer is installed in the opening of the metal case 19, a bolt is passed through the outer periphery thereof, and the ring-shaped contact member 17 is interposed so that the heater 1 and the metal case 19 do not directly contact each other, The wafer heating device 111 was fixed by screwing the nut 20.

  The bottom surface 21 of the metal case 19 is made of 2.0 mm of aluminum and 1.0 mm of aluminum constituting the side wall, and the gas injection port 24, the thermocouple 27, and the power supply terminal 11 are provided on the bottom surface 21 with a predetermined thickness. Installed in position. The distance from the bottom surface 21 to the heater 1 was 20 mm.

  The cross section of the contact member 17 is L-shaped and annular. The upper surface of the L-shaped stepped portion, the lower surface of the heater 1 and the lower surface of the heater 1 are in annular contact, and the width of the contact surface with the heater 1 is 3 mm. Moreover, the material of the contact member was a heat resistant resin.

  Samples Nos. 31 to 39 were prepared by providing the wafer heating apparatus prepared above with the wafer heating heater 1 in which the ratio of Lm / Lr was changed.

And the temperature difference in the wafer W surface was measured by the method similar to Example 1. FIG. The results are as shown in Table 3.

  As shown in Table 3, Sample No. 37 has a large Lm / Lr ratio of 120%, so that the gap Q between the pair of folded arc-shaped bands located on the same circumference widens, and the gap Q that does not have the resistance heating element 5 is provided. As a result, the temperature difference in the wafer W surface could not be reduced efficiently.

  In contrast, sample no. Nos. 31 to 38 have a ratio of Lm / Lr of less than 100% and a wafer temperature difference of 0.22 ° C. or less is preferable.

  Sample No. In Nos. 32-36, the Lm / Lr ratio was 30-80%, and the temperature uniformity within the wafer surface was excellent because the temperature uniformity in the wafer surface was excellent, and the Lm / Lr ratio was 40--40. Sample No. 60% In 33 to 35, the temperature difference could be further reduced.

It is sectional drawing which shows the wafer heating apparatus of this invention. The groove | channel provided in the resistance heating element in the heater of this invention is shown, (a) It is the top view which unevenly distributed the groove | channel on the center side of a plate-shaped object, (b) is unevenly distributed in the outer peripheral side of a plate-shaped object. FIG. It is an enlarged view which shows a part of belt | band | zone of the resistance heating element in the heater of this invention. It is a top view which shows the zone of the resistance heating element in the heater of this invention. (A) is a top view which shows the resistance heating element in the heater of this invention. (B) is a partially enlarged view thereof. It is sectional drawing which shows the conventional wafer heating apparatus. It is a top view which shows the resistance heating element in the conventional heater. It is sectional drawing of the resistance heating element in the conventional heater. It is an enlarged view which shows the groove | channel formed in the resistance heating element in the conventional heater.

Explanation of symbols

W: Wafer m: Groove G: Group of grooves
DESCRIPTION OF SYMBOLS 1, 71: Heater 2, 72: Plate-like body 3, 73: Mounting surface 5, 75: Resistance heating element 6: Power supply part 8: Support pin 10: Temperature measuring element 11, 77: Power supply terminal 12: Gas injection port 16, 80: Bolt 18: Elastic body 19, 79: Metal case 20: Nut 25: Lift pin 26: Through hole 27: Temperature measuring element 110: Heater for wafer heating 111: Wafer heating device

Claims (18)

A heater comprising a strip-like resistance heating element on the surface of a plate-like body, the resistance heating element having a groove substantially parallel to the longitudinal direction, and the groove being unevenly distributed on the center side of the plate-like body . A heater comprising a strip-like resistance heating element on the surface of a plate-like body, the resistance heating element having a groove substantially parallel to the longitudinal direction, and the groove being unevenly distributed on the outer peripheral side of the plate-like body . The heater according to claim 1, wherein the groove is a groove capable of adjusting a resistance value of the resistance heating element. The heater according to any one of claims 1 to 3, wherein a plurality of the grooves are provided substantially in parallel with the longitudinal direction of the resistance heating element to form a group of a plurality of grooves adjacent to each other. The heater according to claim 4, wherein the group is divided into a plurality along the longitudinal direction of the band of the resistance heating element, and the interval between the group and the group is smaller than the width of the band. The heater according to claim 4 or 5, wherein the length of the group is 30 to 97% of the total length of the center line of one of the bands in which each group is formed. The resistance heating element is composed of an arc-shaped band disposed substantially concentrically and a folded arc-shaped band connecting them, and a pair of folded arc-shaped bands positioned on the same circumference at least at one place. The heater according to any one of claims 1 to 6, wherein a distance between them is smaller than a distance between arc-shaped strips arranged substantially concentrically. The distance between the pair of folded arc-shaped bands located on the same circumference of the resistance heating element is smaller than the distance between the arc-shaped bands disposed substantially concentrically at all locations. The heater according to claim 7. The distance between the pair of folded arc-shaped bands located on the same circumference is 30 to 80% of the distance between the arc-shaped bands disposed substantially concentrically. The heater according to 7 or 8. The resistance heating element formed in a substantially concentric shape has a concentric circular outermost resistance heating element band and an inner band whose interval is concentric with the resistance heating element excluding the outermost resistance heating element. The heater according to any one of claims 7 to 9, wherein the heater is smaller than the interval between the bands. One main surface of the plate-like body is a wafer mounting surface, and the other main surface of the plate-like body is provided with a belt-like resistance heating element, and the resistance heating element is provided with an arc-shaped band disposed substantially concentrically. In addition to the folded band connecting them, the groove formed in the arc-shaped band having a substantially parallel groove in the longitudinal direction and arranged in a concentric circle shape is unevenly distributed on the center side of the plate-like body A heater for heating a wafer. One main surface of the plate-like body is a wafer mounting surface, and the other main surface of the plate-like body is provided with a belt-like resistance heating element, and the resistance heating element is provided with an arc-shaped band disposed substantially concentrically. In addition to the folded band connecting them, the groove formed in the arc-shaped band having a substantially parallel groove in the longitudinal direction and arranged in a concentric circle is unevenly distributed on the outer peripheral side of the plate-like body A heater for heating a wafer. The heater according to claim 11 or 12, wherein the groove is a groove capable of adjusting a resistance value of the resistance heating element. The distance between the pair of folded arc-shaped bands located on the same circumference of the resistance heating element is smaller than the distance between the arc-shaped bands disposed substantially concentrically at one place. The heater for heating a wafer according to any one of claims 11 to 13. The distance between the pair of folded arc-shaped bands located on the same circumference of the resistance heating element is smaller than the distance between the arc-shaped bands disposed substantially concentrically at all locations. The heater for heating a wafer according to claim 14. The distance between the pair of folded arc-shaped bands located on the same circumference of the resistance heating element is 30 to 80% of the distance between the arc-shaped bands disposed substantially concentrically. The heater for heating a wafer according to claim 14 or 15. The resistance heating element formed in a substantially concentric shape has a concentric circular outermost resistance heating element band and an inner band whose interval is concentric with the resistance heating element excluding the outermost resistance heating element. The heater for heating a wafer according to any one of claims 11 to 16, wherein the heater is smaller than the interval between the bands. A wafer heating apparatus comprising the wafer heating heater according to any one of claims 11 to 17, wherein the resistance heating element zone having a power feeding portion capable of independently heating the resistance heating body, and the power feeding portion are surrounded. The resistance heating element zone includes a circular resistance heating element zone provided in the center, and an annular resistance heating element zone surrounding the circular resistance heating element zone. Wafer heating device.

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