JP4658913B2 - Wafer support member - Google Patents

Description

  The present invention relates to a wafer heating apparatus mainly used for 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, or a resist solution applied on the wafer. The present invention relates to a wafer support member suitable for forming a resist film by dry baking.

  A wafer support member for heating a semiconductor wafer (hereinafter abbreviated as a wafer) is used in a semiconductor thin film forming process, an etching process, a resist film baking process, and the like in a manufacturing process of a semiconductor manufacturing apparatus.

  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. Wafer support members have been widely used in accordance with demands for miniaturization of wafers and improved accuracy of wafer heat treatment temperature.

  As such a wafer support member, for example, Patent Document 1, Patent Document 2, and Patent Document 3 propose a wafer support member as shown in FIG.

  The wafer support member 71 includes a plate-shaped ceramic body 72 and a metal case 79 as main components, and nitride ceramics or carbide is formed in an opening of a bottomed metal case 79 made of a metal such as aluminum. A plate-shaped ceramic body 72 made of ceramics is fixed with a bolt 80 via a heat insulating connecting member 74 made of a 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 placed on the lower surface. For example, a concentric resistance heating element 75 as shown in FIG. 10 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 79 a of the metal case 79. 78 to be electrically connected.

  By the way, in such a wafer support member 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. It is. Therefore, until now, in order to reduce the temperature difference in the surface of the wafer, the resistance heating element 75 is divided and the temperature is controlled independently.

  Patent Document 4 discloses a wafer support member provided with a plurality of resistance heating element blocks that are easy to control the temperature. As shown in FIG. 7, this resistance heating element forms a block radially divided into four from the center. Further, as shown in FIG. 8, a wafer support member is disclosed in which the resistance heating element at the outer peripheral portion is divided into four blocks and the resistance heating element at the central portion is divided into circular blocks.

  Further, as shown in FIG. 9, Patent Document 5 includes eight resistance heating elements that have the same rectangular planar shape and are controlled independently of each other or in combination with each other. The four resistance heating elements are perpendicular to the radial direction of the wafer whose long sides of the rectangle pass through the center of the arc at positions facing the arcs obtained by dividing the peripheral edge of the wafer into four equal parts in the circumferential direction. The other four resistance heating elements are arranged in the middle of any two resistance heating elements that occupy positions 180 degrees apart from each other in the circumferential direction, among the four resistance heating elements. A wafer support member arranged in parallel to these is disclosed.

However, both have the problem that a very complicated and delicate structure and control are required, and a wafer support member that can heat the temperature distribution more uniformly with a simple structure has been demanded.
JP 2001-203156 A JP 2001-313249 A JP 2002-76102 A JP-A-11-121385 Japanese Patent Laid-Open No. 11-354528

  In recent years, the size of wafers has been increased to improve production efficiency, but the semiconductor elements themselves have also diversified. Manufacturing with large-sized wafers does not necessarily lead to improvement in production efficiency. Therefore, an apparatus that can cope with the wafer size and heat treatment conditions is desired.

  Furthermore, in the chemically amplified resist that has begun to be used with the miniaturization of the wiring of the semiconductor element, not only the uniformity of the temperature of the wafer but also from the moment when the wafer is placed on the heat treatment apparatus until the heat treatment is finished. The transient temperature history is also extremely important, and it is desired that the wafer temperature be stabilized uniformly within about 60 seconds immediately after the wafer is placed.

  However, in the apparatus introduced in Patent Document 3 and Patent Document 5, the semiconductor wafer is directly or at a certain distance from the surface inside the surface region corresponding to the region where the resistance heating element of the plate-like ceramic body is formed. Although a wafer support member having a region to be mounted is shown, the temperature difference in the wafer surface is as large as 0.5 to 1 ° C., and the influence of the low temperature region on the outer periphery of the plate-like ceramic body is large. There is a concern that the response time until the temperature becomes stable may increase.

  In the wafer support member described in Patent Document 4, in the resistance heating element zone shown in FIG. 7, there is a possibility that the temperature difference between the peripheral portion and the center portion of the wafer W cannot be adjusted. In the body zone, even if the temperature difference between the outer peripheral portion and the central portion can be adjusted, the temperature at the intermediate portion may not be adjusted.

  Furthermore, all of them are metal heaters, and there is a possibility that the time for heating the wafer W uniformly, or for rapidly raising or lowering the temperature of the wafer W may be increased.

  As a result of intensive studies on the above problems, the present inventors have provided a wafer support having a plurality of resistance heating element zones on one main surface of a plate-like ceramic body and a mounting surface on which the wafer is placed on the other main surface. The member is fixed via a power supply part that supplies power independently to the resistance heating element in the resistance heating element zone, and a ring-shaped contact member whose thermal conductivity is smaller than the thermal conductivity of the plate-like ceramic body A metal case surrounding the power feeding portion, the metal case having a gas injection port for cooling the plate-like ceramic body, and the resistance heating element zone having a circular resistance heating at the center. A body zone and three annular resistance heating element zones concentrically outside the circular resistance heating element zone, and the outermost resistance heating element zone includes a plurality of outermost circles divided in the circumferential direction. Arc pattern and the circle And a coupling pattern are connected in sequence to Jo pattern, the spacing between the arc-like pattern, smaller than the difference between the outer diameter of the resistance heating element zone diameter and the outermost of the plate-like ceramic body.

  Further, the present invention is a wafer support member comprising a plurality of resistance heating element zones on one main surface of a plate-like ceramic body, and a mounting surface on which the wafer is placed on the other main surface, the resistance heating element A power supply part that supplies power independently to the resistance heating element of the zone, and a metal that surrounds the power supply part fixed via a ring-shaped contact member having a thermal conductivity smaller than that of the plate-like ceramic body And having the case interposed through the contact member so that the plate-shaped ceramic body and the metal case do not directly contact, the resistance heating element zone is a circular resistance heating element zone provided in the center, The circular resistance heating element zone is composed of three concentric annular resistance heating element zones outside the circular resistance heating element zone, and the outermost peripheral resistance heating element zone includes a plurality of outermost arc-shaped patterns divided in the circumferential direction, Arc shape And a coupling pattern are connected in sequence to turn, the spacing between the arc-like pattern, smaller than the difference between the outer diameter of the resistance heating element zone diameter and the outermost of the plate-like ceramic body.

  Furthermore, the outer diameter D1 of the resistance heating element zone at the center is 15 to 40% of the outer diameter D of the outermost resistance heating element zone. The outer diameter D2 of the body zone is 40 to 60% of the outer diameter D, and the inner diameter D3 of the outermost resistance heating element zone is 60 to 85% of the outer diameter D of the outermost resistance heating element zone.

  The diameter of a circle surrounding all the resistance heating elements in the resistance heating element zone and in contact with the plurality of resistance heating elements is 90 to 99% of the diameter of the plate-like ceramic body.

  In particular, the ratio of the area of the resistance heating element in the circle to the area of the circle surrounding all the resistance heating elements in the resistance heating element zone and in contact with the plurality of resistance heating elements is 5 to 50%.

  The contact member has a circular cross section.

  As described above, according to the present invention, there is provided a wafer support member including a plurality of resistance heating element zones on one main surface of a plate-shaped ceramic body and a mounting surface on which a wafer is placed on the other main surface. A power supply unit for supplying power independently to the resistance heating element in the resistance heating element zone, and the power supply fixed via a ring-shaped contact member having a thermal conductivity smaller than that of the plate-like ceramic body. A metal case surrounding the portion, the metal case is provided with a gas injection port for cooling the plate-like ceramic body, the resistance heating element zone is a circular resistance heating element zone provided in the center, The resistance heating element zone is composed of three concentric annular resistance heating element zones on the outer side of the circular resistance heating element zone, and the outermost resistance heating element zone includes a plurality of outermost arc-shaped patterns divided in the circumferential direction, Continuing to arc pattern A temperature difference in the wafer plane when the interval between the arc-shaped patterns is smaller than the difference between the diameter of the plate-shaped ceramic body and the outer diameter of the outermost resistance heating element zone. And a wafer holding member having excellent temperature response characteristics can be obtained.

  The plate-like ceramic body has a plurality of resistance heating element zones on one main surface, and a wafer support member having a mounting surface on which the wafer is placed on the other main surface, wherein the resistance heating element zone generates heat. A power supply section that supplies power independently to the body, and a metal case that surrounds the power supply section and that is fixed via a ring-shaped contact member having a thermal conductivity smaller than that of the plate-shaped ceramic body. The plate-like ceramic body and the metal case are interposed directly through the contact member, and the resistance heating element zone includes a circular resistance heating element zone provided at the center, and the circular resistance It comprises three concentric annular resistance heating element zones outside the heating element zone, and the outermost resistance heating element zone includes a plurality of outermost arc-shaped patterns divided in the circumferential direction, and the arc-shaped pattern. In If the distance between the arc-shaped patterns is smaller than the difference between the diameter of the plate-shaped ceramic body and the outer diameter of the outermost resistance heating element zone, A wafer holding member having a small temperature difference and excellent temperature response characteristics can be obtained.

  The outer diameter D1 of the central resistance heating element zone is 15 to 40% of the outer diameter D of the outermost resistance heating element zone, and the outer resistance heating element next to the central resistance heating element zone. The outer diameter D2 of the zone is 40 to 60% of the outer diameter D, and the inner diameter D3 of the outermost resistance heating element zone is 60 to 85% of the outer diameter D of the outermost resistance heating element zone. A wafer holding member having a small temperature difference and excellent temperature response characteristics can be obtained.

  The plate-like ceramic body has a plurality of resistance heating element zones on one main surface, and a wafer support member having a mounting surface on which the wafer is placed on the other main surface, wherein the resistance heating element zone generates heat. A power supply section for supplying power independently to the body; and a metal case surrounding the power supply section, wherein the resistance heating element zone includes a circular resistance heating element zone provided at a central portion, and the circular resistance heat generation. It consists of three annular resistance heating element zones that are concentric outside the body zone, and of the three annular resistance heating element zones, the innermost resistance heating element zone is divided into two equal parts. The next outer resistance heating element zone has four fan-like shapes in which the ring is divided into four equal parts in the circumferential direction, and the outermost resistance heating element zone has an annular shape in the circumferential direction. Wafers with high thermal uniformity due to eight fan-shaped parts Support member is obtained.

  Embodiments of the present invention will be described below.

  FIG. 1 is a cross-sectional view showing an example of a wafer support member 1 according to the present invention, on which one main surface of a plate-like ceramic body 2 made of ceramics mainly composed of silicon carbide or aluminum nitride is mounted. In addition to the surface 3, a resistance heating element 5 is formed on the other main surface, and a power supply unit 6 electrically connected to the resistance heating element 5 is provided, and a power supply terminal 11 is connected to the power supply unit 6. A metal case 19 surrounding these power feeding portions 6 is fixed to the peripheral portion of the other main surface of the plate-like ceramic body 2 via a connecting member 17.

  Further, the wafer lift pins 25 can move the wafer W up and down through the holes penetrating the plate-like ceramic body 2 to place or drop the wafer W on the mounting 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 temperature W of the plate ceramic body 2 can be heated by the temperature measuring element 27 to heat the wafer W.

  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 due to contact of the wafer W or the like. In addition, when the resistance heating element 5 is divided into a plurality of zones, the temperature of each zone is controlled independently to supply power to the power supply terminals 11 of each power supply unit 6, and the temperature of each temperature measuring element 27 is changed. The electric power applied to the power supply terminal 11 is adjusted so as to be each set value so that the surface temperature of the wafer W placed on the placement surface 3 is uniform.

  The resistance heating element 5 is formed with a power feeding portion 6 made of a material such as gold, silver, palladium, platinum or the like, and the power feeding terminal 11 is brought into contact with the power feeding portion 6 to ensure conduction. As long as the power supply terminal 11 and the power supply unit 6 are a method that can ensure conduction, a method such as soldering or brazing may be used.

  The concentric three circular resistance heating element zones 4 corresponding to the mounting surface 3 of the wafer W are divided into the atmosphere around the wafer W in order to uniformly heat the surface of the disk-shaped wafer W. Although it is affected by the wall surface and gas flow that opposes the wafer W, in order not to vary the surface temperature of the disk-shaped wafer W, the opposing surface of the periphery of the wafer W, the upper surface, and the flow of atmospheric gas are This is because it is designed to be symmetric with respect to the center. In order to uniformly heat the wafer W, the wafer support member 1 matched to the above-mentioned environment that is symmetric with respect to the wafer W is necessary, and it is preferable to form the resistance heating element zone 4 by dividing the mounting surface 3 symmetrically. .

  In particular, in order to uniformly heat the surface temperature of the wafer W of 300 mm or more, it is preferable that there are three concentric annular resistance heating element zones.

  FIG. 2A shows a wafer support member 1 according to the present invention, which includes a plurality of resistance heating element zones on one main surface of a plate-like ceramic body, a circular resistance heating element zone 4a at the center, and a concentric circle on the outside thereof. The example of arrangement | positioning of each resistance heating element zone 4 provided with resistance heating element zones 4bc and 4dg and resistance heating element zone 4ho in these three rings is shown. In this example, in order to improve the thermal uniformity of the wafer W, the resistance heating element 5 is divided corresponding to four resistance heating element zones.

  The outer diameter D1 of the resistance heating element zone 4a at the center of the wafer support member 1 of the present invention is 15 to 40% of the outer diameter D of the resistance heating element zone 4ho at the outer periphery, and the outer resistance heating element zone 4bc. The outer diameter D2 is 40 to 60% of the outer diameter D of the outer peripheral resistance heating element zone, and the inner diameter D3 of the outermost resistance heating element zone is 60 to 85 of the outer diameter D of the outermost resistance heating element zone. % Is preferable because the in-plane temperature difference of the wafer W can be reduced.

  The outer diameter D of the resistance heating element zone 4ho on the outer peripheral portion is the resistance heating element 5h, 5i constituting the resistance heating element zone 4ho when viewed from a projection plane parallel to the other main surface of the plate-like ceramic body 2. 5j, 5k, 5l, 5m, 5n, and 5o. Similarly, the outer diameter D2 of the resistance heating element zone 4bc is the diameter of a circle surrounding and contacting the resistance heating elements 5b and 5c constituting the resistance heating element zone 4bc. D3 is the diameter of a circle in contact with the inside of the resistance heating elements 5h, 5i, 5j, 5k, 5l, 5m, 5n, 5o.

If the outer diameter D1 is less than 15% 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 temperature at the center of the resistance heating element zone 4a is increased. This is because there is a risk that the temperature in the center portion will not rise. 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. The outer diameter D1 is preferably 20 to 30% of D.
More preferably, the in-plane temperature difference of the wafer W can be further reduced by setting the outer diameter D1 to 22 to 26% of D.

  Further, when the outer diameter D2 is less than 40% of the outer diameter D, the peripheral portion of the wafer support member 1 is easily cooled. Therefore, the amount of heat generated in the resistance heating element zone 4dg is increased in order to prevent a decrease in the temperature around the wafer W. In this case, the temperature inside the resistance heating element zone 4dg close to the center of the wafer W becomes high, and the in-plane temperature difference of the wafer W may be increased. When the outer diameter D2 exceeds 60% of the outer diameter D, the temperature of the resistance heating element zone 4dg rises even if the heating value of the resistance heating element zone 4dg is increased so as to prevent a decrease in the temperature around the wafer W. However, there is a possibility that the temperature decrease around the wafer W reaches the resistance heating element zone 4bc and the temperature outside the resistance heating element zone 4bc is lowered. Preferably, when the outer diameter D2 is 45% to 54% of the outer diameter D, and more preferably 48 to 51%, the in-plane temperature difference of the wafer W can be further reduced.

  Further, when the outer diameter D3 is less than 60% of the outer diameter D, the peripheral portion of the wafer support member 1 is easily cooled, so that the amount of heat generated in the resistance heating element zone 4ho is increased in order to prevent a decrease in the temperature around the wafer W. In this case, the temperature inside the resistance heating element zone 4ho close to the center of the wafer W is increased, and the in-plane temperature difference of the wafer W may be increased. If the outer diameter D2 exceeds 85% of the outer diameter D, the temperature of the resistance heating element zone 4ho rises even if the heating value of the resistance heating element zone 4ho is increased in order to prevent a decrease in the temperature around the wafer W. However, there is a possibility that the temperature decrease around the wafer W reaches the resistance heating element zone 4dg, and the temperature outside the resistance heating element zone 4dg is lowered. Preferably, when the outer diameter D2 is 65% to 75% of the outer diameter D, and more preferably 67 to 70%, the in-plane temperature difference of the wafer W can be further reduced.

  Further, it was found that the in-plane temperature difference of the wafer W can be reduced by correcting the left and right subtle asymmetry generated from the environment around the wafer support member 1 and the symmetric heating element thickness variation.

  FIG. 2B shows an example of the resistance heating element zone 4 of the wafer support member 1 of the present invention. Out of the three annular resistance heating element zones 4bc, 4dg, 4ho, the innermost resistance heating element zone 4bc is two fan-shaped resistance heating element zones 4b, 4c obtained by dividing the ring into two equal parts. The outer resistance heating element zone 4dg is four fan-shaped resistance heating element zones 4d, 4e, 4f, and 4g obtained by dividing the ring into four in the circumferential direction, and the outer resistance heating element zone 4ho is a circular shape. In order to make the surface temperature of the wafer W uniform, it is composed of eight fan-shaped resistance heating element zones 4h, 4i, 4j, 4k, 4l, 4m, 4n, and 4o obtained by dividing the ring into eight equal parts in the circumferential direction. Is preferable.

  Each of the resistance heating element zones 4a to 4o of the wafer support member 1 can generate heat independently, and includes resistance heating elements 5a to 5o corresponding to the resistance heating element zones 4a to 4o.

  Although the annular resistance heating element zones 4bc, 4dg, and 4ho are respectively divided into two, four, and eight in the radial direction, this is not restrictive.

  The boundary line of the resistance heating element zones 4b and 4c in FIG. 2B is a straight line, but is not necessarily a straight line and may be a wavy line. The resistance heating element zones 4b and 4c are concentric heating element zones. It is preferable that it is centrosymmetric with respect to the center.

  Similarly, the boundary lines of the resistance heating element zones 4d and 4e, 4e and 4f, 4f and 4g, 4g and 4d do not necessarily have to be straight lines, and may be wavy lines. It is preferably centrosymmetric with respect to the center of the zone.

  Each of the resistance heating elements 5 is preferably produced by a printing method or the like, and is formed to have 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. The amount of heat generation varies, and the in-plane temperature difference between the wafer W increases, which is not preferable. In order to prevent the temperature variation caused by the variation in thickness of the resistance heating element, it has been found that it is effective to divide the individual resistance heating elements 5 having a large outer diameter, which is composed of one resistance heating element.

  Therefore, the concentric annular resistance heating element zone 4bc excluding the central portion of the wafer W mounting surface 3 is divided into left and right parts, and the larger annular resistance heating element zone 4dg is divided into four parts. By dividing the resistance heating element zone 4ho into eight, the printing size of the resistance heating element 5 in the resistance heating element zone 4 can be reduced, so that the thickness of each part of the resistance heating element 5 can be made uniform. Furthermore, the subtle temperature difference between the front, back, left and right of the wafer W can be corrected to make the surface temperature of the wafer W uniform.

  It should be noted that the resistance heating elements 5b, 5c, 5d, 5e, 5f, 5g, 5h, 5i, 5j, 5k, 5l, 5m, 5n, and 5o shown in FIG. The heating element shows an example in which these folding patterns are spiral. Moreover, the pattern which compounded these patterns may be sufficient.

  Further, the wafer support member 1 of the present invention is a wafer support member 1 provided with a resistance heating element 5 on one main surface of a plate-like ceramic body 2, and the outer periphery of the plate-like ceramic body 2 as shown in FIG. The resistance heating elements 5b, 5c, 5d, 5e, 5f, 5g, 5h, 5i, 5j, 5k, 5l, 5m, 5n, and 5o located in the section are concentric with the portion far from the center of the plate-like ceramic body 2. It is preferable that the circular arc pattern 51 and the connection pattern 52 continuously connected to these arc-shaped patterns 51 are formed. The power supply unit 6 that supplies power to the resistance heating element 5 and a metal case 19 that surrounds the power supply unit 6 are provided with a wafer heating surface on the other main surface of the plate-like ceramic body 2, and the other main surface. Is preferably 90 to 99% of the diameter DP of the plate-like ceramic body 2.

  If the diameter D of the circle C is smaller than 90% of the diameter DP of the plate-like ceramic body 2, the time for rapidly raising or lowering the temperature of the wafer increases, and the temperature response characteristics of the wafer W 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-shaped ceramic 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-shaped ceramic body 2. The heating efficiency for heating the is deteriorated. Furthermore, since the plate-like ceramic body 2 becomes large, the installation area of the wafer manufacturing apparatus becomes large, which is not preferable because the operating 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.

  When the diameter D of the circle C is larger than 99% of the diameter DP of the plate-like ceramic body 2, the distance between the contact member 17 and the outer periphery of the resistance heating element 5 is small, and heat is transferred from the outer periphery of the resistance heating element 5 to the contact member 17. Heat flows even from a portion where the arc-shaped pattern 51 in contact with the outer circumference circle C does not exist, and the outer arc-shaped pattern 51 is bent toward the center of the plate-like ceramic body 2. There is a possibility that the temperature of the portion P where the arc-shaped pattern 51 is missing is lowered along the circle C surrounding the resistance heating element 5 and the in-plane temperature difference of the wafer W is increased. More preferably, the diameter D of the circle C of the resistance heating element 5 is 92 to 97% of the diameter DP of the plate-like ceramic body 2.

  Further, as shown in FIG. 1, when the plate ceramic body 2 and the metal case 19 have substantially the same outer diameter and the plate ceramic body 2 is supported by the metal case 19 from below, the temperature difference in the surface of the wafer W is reduced. The diameter D of the circle C of the resistance heating element 5 is 92 to 95%, more preferably 93 to 95% of the diameter DP of the plate-like ceramic body 2.

  On the other hand, when the metal case is connected so as to cover the outer peripheral surface of the plate-like ceramic body 2 as shown in FIG. 5, the diameter D of the circle C of the resistance heating element 5 is 95 of the diameter DP of the plate-like ceramic body 2. -98% is preferable, More preferably, it is 96-97%.

  Further, the wafer support member 1 of the present invention includes, for example, an arc-shaped pattern 51 in contact with the circle C of the resistance heating element 5 of FIG. 3 and a connection pattern 52 continuously connected to the arc-shaped pattern 51. The space S between the blank areas P having no arc-shaped pattern in a part of C is smaller than the difference between the diameter DP of the plate-like ceramic body and the diameter D of the circle C (hereinafter abbreviated as L). preferable. If the distance S is larger than L, the heat of the blank area P flows to the peripheral part of the plate-shaped ceramic body, and the temperature of the blank area P may be lowered. However, if the interval S is smaller than L, the temperature of the blank area P is unlikely to decrease, and the temperature in the peripheral portion of the wafer W placed on the mounting surface 3 of the plate-like ceramic body 2 does not decrease, but the temperature within the wafer W surface. This is preferable because the difference is reduced.

  In order not to lower the temperature of the blank area P, it is necessary to increase the temperature of the blank area. If the resistance of the connection pattern 52 for heating the blank area is equal or increased to increase the heat generation amount, The possibility that the temperature is lowered is reduced, and the in-plane temperature of the wafer W is preferably uniform. When the resistance heating element 5 created by a printing method or the like is planar, the resistance of the connection pattern 52 can be increased by making the line width Ws of the connection pattern 52 smaller than the line width Wp of the arc-shaped pattern 51. By increasing the temperature of the pattern 52 above the temperature of the arc-shaped pattern 51, the in-plane temperature of the wafer W can be made uniform.

  One main surface side of the plate-like ceramic body 2 having a plate thickness of 1 to 7 mm is used as a mounting surface 3 on which a wafer is placed, and a wafer support member provided with a resistance heating element 5 on the lower surface of the plate-like ceramic body 2 1, the thickness of the resistance heating element 5 is 5 to 50 μm, and the area of the circle C surrounding the resistance heating element 5 when viewed in a projection plane parallel to the main surface of the plate-like ceramic body 2. The ratio of the area of the resistance heating element 5 in the circle C is preferably 5 to 50%.

That is, if the ratio of the area of the resistance heating element 5 in the circle C to the area of the circle C surrounding the resistance heating element 5 is less than 5%, Is too large, the surface temperature of the mounting surface 3 corresponding to the space S1 without the resistance heating element 5 is smaller than the other portions, and the temperature of the mounting surface 3 is made uniform. Conversely, if the ratio of the area of the resistance heating element 5 in the circle C to the area of the circle C surrounding the resistance heating element 5 exceeds 50%, the plate-like ceramic body 2 and the resistance heating element Even if the difference in thermal expansion coefficient between the body 5 and the body 5 is approximated to 3.0 × 10 ⁻⁶ / ° C. or less, the thermal stress acting between the two is too large, so that the plate-like ceramic body 2 is deformed. Although it is made of a hard ceramic sintered body, the thickness t is 1 mm to 7 mm. Therefore, when the resistance heating element 5 is heated, warping occurs in the plate-like ceramic body 2 so that the mounting surface 3 side is concave, and as a result, the temperature of the central portion of the wafer W is lower than the peripheral edge. This is because there is a risk of temperature variation.

  Preferably, the ratio of the area of the resistance heating element 5 in the circle C to the area of the circle C surrounding the resistance heating element 5 is 10% to 30%, more preferably 15% to 25%. .

  More specifically, the resistance heating element 5 has a counter area that opposes the outer peripheral portion, and the interval S1 between the counter areas is 0.5 mm or more, and is not more than three times the plate thickness of the plate-like ceramic body 2. Preferably there is. If the interval S1 between the opposing regions is 0.5 mm or less, when the resistance heating element 5 is printed and formed, whisker-like protrusions may occur in the opposing region of the resistance heating element 5 and the portion may be short-circuited. Further, when the interval S1 between the opposing regions exceeds three times the thickness of the plate-like ceramic body 2, a cool zone is generated on the surface of the wafer W corresponding to the opposing region S1, and the in-plane temperature difference of the wafer W may be increased. Because there is.

  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 becomes difficult to uniformly print the resistance heating element 5 by screen printing, and the thickness of the resistance heating element 5 exceeds 50 μm. And even if the ratio of the area occupied by the resistance heating element 5 to the circle C is 50% or less, the thickness of the resistance heating element 5 is large, the rigidity of the resistance heating element 5 is increased, and the temperature change of the plate-like ceramic body 5 There is a possibility that the plate-like ceramic body 2 is deformed due to the influence of expansion and contraction of the resistance heating element 5. In addition, it is difficult to print to a uniform thickness by screen printing, and the temperature difference on the surface of the wafer W may increase. A preferable thickness of the resistance heating element 5 is 10 to 30 μm.

  A more detailed configuration will be described.

  FIG. 1 is a cross-sectional view showing an example of a wafer support member according to the present invention, and shows one main surface of a plate-like ceramic body 2 having a plate thickness t of 1 to 7 mm and a Young's modulus of 100 to 200 ° C. of 200 to 450 MPa. In addition to the mounting surface 3 on which the wafer W is placed, a resistance heating element 5 is formed on the other main surface, and a power feeding unit 6 electrically connected to the resistance heating element 5 is provided.

  As the material of the plate-like ceramic body 2 having a Young's modulus of 100 to 200 ° C. of 200 to 450 MPa, alumina, silicon nitride, sialon, and aluminum nitride can be used. Of these, aluminum nitride is particularly 50 W / (m · K). ) Or more, and also has a high thermal conductivity of 100 W / (m · K) or more, and is excellent in corrosion resistance and plasma resistance against corrosive gases such as fluorine and chlorine. It is suitable as the material.

  The thickness of the plate-like ceramic body 2 is more preferably 2 to 5 mm. When the thickness of the plate-like ceramic body 2 is less than 2 mm, the strength of the plate-like ceramic body 2 is lost, and the heat generated during cooling when the cooling air from the gas injection port 24 is blown when heated by the heat generated by the resistance heating element 5. This is because the plate-shaped ceramic body 2 may not be able to withstand stress and may crack. On the other hand, if the thickness of the plate-like ceramic body 2 exceeds 5 mm, the heat capacity of the plate-like ceramic body 2 increases, so that there is a possibility that the time until the temperature at the time of heating and cooling becomes stable becomes longer.

  The plate-like ceramic body 2 has a ring-shaped contact member 17 so that the bolt 16 passes through the outer periphery of the opening of the bottomed metal case 19 and the plate-like ceramic body 2 and the bottomed metal case 19 do not directly contact each other. The elastic body 18 is interposed from the bottomed metal case 19 side, and the nut 20 is screwed to be elastically fixed. Thereby, even if the bottomed metal case 19 is deformed when the temperature of the plate-like ceramic body 2 fluctuates, the elastic body 18 absorbs this, thereby suppressing the warp of the plate-like ceramic body 2, It is possible to prevent temperature variations due to warpage of the plate-shaped ceramic body 2 from occurring on the wafer surface.

  The cross-section of the ring-shaped contact member 17 may be polygonal or circular, but when the plate-like ceramic body 2 and the contact member 17 are in contact with each other in a plane, the contact portion where the plate-like ceramic body 2 and the contact member 17 are in contact with each other If the width is 0.1 mm to 13 mm, the amount of heat of the plate-like ceramic body 2 flowing to the bottomed metal case 19 via the contact member 17 can be reduced. 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 is fixed to the plate-like ceramic body 2, and the contact member may be damaged. Further, when the width of the contact portion of the contact member 17 exceeds 13 mm, the heat of the plate-like ceramic body 2 flows to the contact member, the temperature of the peripheral portion of the plate-like ceramic body 2 is lowered, and the wafer W is heated uniformly. It becomes difficult to do. Preferably, the width of the contact portion between the contact member 17 and the plate-like ceramic body 2 is 0.1 mm 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 ceramic body 2. If the thermal conductivity of the contact member 17 is smaller than the thermal conductivity of the plate-like ceramic body 2, the temperature distribution in the wafer W surface placed on the plate-like ceramic body 2 can be heated uniformly, and the plate-like ceramic body 2. When the temperature is raised or lowered, the amount of heat transferred to the contact member 17 is small, and there is little thermal interference with the bottomed metal case 19, so that it is easy to change the temperature quickly.

  In the wafer support member 1 in which the thermal conductivity of the contact member 17 is smaller than 10% of the thermal conductivity of the plate-like ceramic body 2, the heat of the plate-like ceramic body 2 hardly flows to the bottomed metal case 19, and the atmosphere gas (here In this case, the amount of heat flowing due to heat transfer by air) or radiant heat transfer increases and the effect is small.

  When the thermal conductivity of the contact member 17 is higher than the thermal conductivity of the plate-like ceramic body 2, the heat around the plate-like ceramic body 2 flows to the bottomed metal case 19 via the contact member 17 and is present. While heating the bottom metal case 19, the temperature of the peripheral part of the plate-shaped ceramic 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 ceramic body 2 by injecting air from the gas injection port 24, the cooling time is large because the temperature of the bottomed metal case 19 is high. Or when it is heated to a certain temperature, there is a possibility that the time until the temperature reaches a certain temperature is increased.

  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. By setting such a Young's modulus, the width of the contact portion is as small as 0.1 mm to 8 mm, and the plate-like ceramic body 2 is fixed to the bottomed metal case 19 with the bolt 16 via the contact member 17, The contact member 17 is not deformed, and the plate-shaped ceramic body 2 can be held with high accuracy without being displaced or changing in parallelism.

  In addition, the precision which cannot be obtained with the contact member which consists of resin which added fluororesin and glass fiber like Unexamined-Japanese-Patent No. 2001-313249 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 a low thermal conductivity, so-called kovar of stainless steel or Fe—Ni—Co alloy is preferable, and the material of the contact member 17 is selected so as to be smaller than the thermal conductivity of the plate-like ceramic body 2. Is preferred.

  Furthermore, since the contact portion between the contact member 17 and the plate-like ceramic body 2 is small, and even if the contact portion is small, the contact portion is not liable to be lost and particles can be generated. The cross section of the contact member 17 cut at a plane perpendicular to the body 2 is preferably circular rather than polygonal. When a circular wire having a cross section diameter of 1 mm or less is used as the contact member 17, the plate-like ceramic body 2 and the bottomed metal case 19 are used. It is possible to raise and lower the temperature of the wafer W evenly and quickly without changing the position of the wafer W.

  Next, the bottomed metal case 19 has a side wall portion 22 and a bottom surface 21, and the plate-like ceramic body 2 is installed so as to cover the opening of the bottomed metal case 19. Further, the bottomed metal case 19 is provided with a hole 23 for discharging a cooling gas, and a power supply terminal for conducting to a power supply portion 6 for supplying power to the resistance heating element 5 of the plate-like ceramic body 2. 11. A gas injection port 24 for cooling the plate-like ceramic body 2 and a thermocouple 27 for measuring the temperature of the plate-like ceramic body 2 are provided.

  The depth of the bottomed metal case 19 is 10 to 50 mm, and the bottom surface 21 is preferably installed at a distance of 10 to 50 mm from the plate-like ceramic 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 ceramic body 2 and the bottomed metal case 19, and at the same time, there is a heat insulation effect from the outside, so the temperature of the mounting surface 3 is constant. This is because the time until the temperature becomes uniform is shortened.

  Then, work such as placing the wafer W on the placement surface 3 or lifting it from the placement surface 3 is performed by lift pins 25 installed in the bottomed metal case 19 so as to be movable up and down. 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 variation due to contact with each other.

  Further, in order to heat the wafer W by the wafer heating apparatus 1, the lift pin 25 is 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 pin 25. The wafer W is then placed on the placement surface 3.

  Next, when the wafer support member 1 is used for forming a resist film, if the main component of the plate-like ceramic body 2 is silicon carbide, it does not react with moisture in the atmosphere and does not generate gas. Even when the resist film is applied to the wafer W, 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.

In the silicon carbide sintered body forming the plate-like ceramic 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.

  On the other hand, when the silicon carbide sintered body is used as the plate-like ceramic body 2, glass or resin is used as an insulating layer for maintaining insulation between the plate-like ceramic body 2 having semiconductivity and the resistance heating element 5. When glass is used, if the thickness is less than 100 μm, the withstand voltage is less than 1.5 kV and the insulation cannot be maintained. Conversely, if the thickness exceeds 400 μm, the plate-like ceramic body 2 is formed. Since the thermal expansion difference between the silicon carbide sintered body and the aluminum nitride sintered body becomes too large, cracks are generated and the insulating layer does not function. 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 desirably in the range of 200 μm to 350 μm.

  Furthermore, the main surface opposite to the mounting surface 3 of the plate-shaped ceramic body 2 has a flatness of 20 μm or less and a surface roughness of the center line average roughness from the viewpoint of improving the adhesion with the insulating layer 4 made of glass or resin. The thickness (Ra) is preferably polished to 0.1 μm to 0.5 μm.

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

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

  In addition, as a means for depositing an insulating layer made of glass on the plate-like ceramic body 2, an appropriate amount of the glass paste is dropped on the center of the plate-like ceramic body 2, and is spread and applied uniformly by a spin coating method. Alternatively, the glass paste may be baked at a temperature of 600 ° C. or higher after being uniformly applied by a screen printing method, a dipping method, a spray coating method, or the like. When glass is used as the insulating layer, the surface of the plate-like ceramic 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. to deposit the insulating layer. By subjecting to an oxidation treatment, adhesion to an insulating layer made of glass can be enhanced.

  As the pattern shape of the resistance heating element 5 of the present invention, it is divided into a plurality of blocks as shown in FIG. 3 and FIG. 4, and each block is a spiral or zigzag pattern composed of an arc-shaped pattern and a linear pattern. Since the wafer support member 1 of the present invention is important to heat the wafer W uniformly, it is important that these pattern shapes have a uniform density of each part of the strip-shaped resistance heating element 5. preferable. However, in the resistance heating element pattern in which a portion where the resistance heating elements 25 are closely spaced and a rough portion appear alternately in the radial direction from the center of the plate-like ceramic body 22 as shown in FIG. The surface temperature of the wafer W corresponding to is small, the temperature of the wafer W corresponding to the dense portion is large, and the entire surface of the wafer W cannot be heated uniformly, which is not preferable.

  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 ceramic body 2 by a printing method. As the metal particles, Au, Ag, Cu, It is preferable to use at least one metal of Pd, Pt, and Rh, and the glass frit is made of an oxide containing B, Si, and Zn, and is 4.5 × 10 4 smaller than the thermal expansion coefficient of the plate-like ceramic body 2. It is preferable to use a low expansion glass of ⁻⁶ / ° C. or lower, and it is preferable to use at least one selected from silicon oxide, boron oxide, alumina, and titania as the metal oxide.

  Here, the reason why at least one kind of metal of Au, Ag, Cu, Pd, Pt, Rh is used as the metal particles forming the resistance heating element 5 is that the electric resistance is small.

The glass frit forming the resistance heating element 5 is made of an oxide containing B, Si, and 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 ceramic body 2. In order to make the thermal expansion coefficient of the resistance heating element 5 close to the thermal expansion coefficient of the plate-like ceramic body 2, a low expansion glass of 4.5 × 10 ⁻⁶ / ° C. or less which is smaller than the thermal expansion coefficient of the plate-like ceramic body 2 is used. It is because it is preferable to use.

  In addition, as the metal oxide forming the resistance heating element 5, using at least one selected from silicon oxide, boron oxide, alumina, and titania has excellent adhesion to the metal particles in the resistance heating element 5, In addition, the thermal expansion coefficient is close to the thermal expansion coefficient of the plate-like ceramic body 2 and the adhesiveness with the plate-like ceramic 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 ceramic 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 has a thermal expansion coefficient difference of 3.0 × 10 ⁻⁶ / ° C. or less from the plate-like ceramic body 2. It is preferable.

That is, it is difficult to manufacture the difference in coefficient of thermal expansion between the resistance heating element 5 and the plate-like ceramic body 2 to 0.1 × 10 ⁻⁶ / ° C. Conversely, the resistance heating element 5 and the plate-like ceramic body 2 When the difference between the thermal expansion coefficients of the two exceeds 3.0 × 10 ⁻⁶ / ° C., when the resistance heating element 5 is heated, the mounting surface 3 side is affected by the thermal stress acting between the plate-like ceramic body 2. This is because there is a risk of warping in a concave shape.

Further, as the resistance heating element 5 material deposited on the insulating layer, a simple metal such as gold (Au), silver (Ag), copper (Cu), palladium (Pd) or the like is directly applied by a vapor deposition method or a plating method. Either a metal paste or a conductive metal oxide such as rhenium oxide (Re ₂ O ₃ ) or lanthanum manganate (LaMnO ₃ ) or a paste in which the above metal material is dispersed in a resin paste or glass paste. The conductive material may be prepared and printed in a predetermined pattern shape by a screen printing method or the like and then baked, and the conductive material may be bonded with a matrix made of resin or glass. When glass is used as the matrix, either crystallized glass or amorphous glass may be used, but crystallized glass is preferably used in order to suppress a change in resistance value due to thermal cycling.

  However, when silver (Ag) or copper (Cu) is used for the resistance heating element 5 material, migration may occur. In such a case, the same as the insulating layer is provided so as to cover the resistance heating element 5. What is necessary is just to coat | coat the coating layer which consists of material with the thickness of about 40-400 micrometers.

  Further, regarding a method of feeding power to the resistance heating element 5, the power feeding terminal 11 installed on the bottomed metal case 19 is pressed against the power feeding portion 6 formed on the surface of the plate-like ceramic body 2 by a spring (not shown). Secure the connection and supply power. This is because if the terminal portion made of metal is embedded in the plate-like ceramic 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, the thermal stress due to the temperature difference between the plate-shaped ceramic body 2 and the bottomed metal case 19 is reduced by pressing the power supply terminal 11 with a spring to ensure electrical connection. The electrical conduction 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 ceramic body 2 is measured by a thermocouple 27 whose tip is embedded in the plate-like ceramic 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-shaped ceramic 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. 5, a plurality of support pins 8 are provided on one main surface of the plate-like ceramic body 2, and the wafer W is placed at a certain distance from one main surface of the plate-like ceramic body 2. You may make it hold | maintain.

  Although FIG. 1 shows the wafer support member 1 having only the resistance heating element 5 on the other main surface 3 of the plate-like ceramic body 2, the present invention is arranged between the main surface 3 and the resistance heating element 5. Needless to say, an electrode for electrostatic adsorption or plasma generation may be embedded.

  First, 1.0% by mass of yttrium oxide in terms of weight was added to the aluminum nitride powder, and further kneaded for 48 hours with a ball mill using isopropyl alcohol and urethane balls to produce an aluminum nitride slurry.

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

  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. A plate-like ceramic body having the same was produced.

  Then, the aluminum nitride sintered body is ground to produce a plurality of disk-shaped ceramic bodies 2 having a disk thickness of 3 mm and a diameter of 315 mm to 330 mm, and further penetrates three places evenly on a concentric circle of 60 mm from the center. A hole was formed. The through-hole diameter was 4 mm.

  Next, in order to deposit the resistance heating element 5 on the plate-like ceramic body 2, a conductor paste produced 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 printed in a predetermined pattern shape by a screen printing method, heated to 150 ° C. to dry the organic solvent, further degreased at 550 ° C. for 30 minutes, and then baked at a temperature of 700 to 900 ° C. Thus, the resistance heating element 5 having a thickness of 50 μm was formed.

  The resistance heating element zone 4 is arranged such that a resistance heating element zone is formed in a circular shape having a diameter of D1 mm at the center, the outer ring is divided into two equivalent resistance heating element zones, and the outer side is outside. A total of 15 resistance heating element zone configurations in which an annular ring having a diameter of D2 mm is divided into four resistance heating element zones, and an annular ring having an inner diameter D3 of the outermost resistance heating element zone is divided into eight resistance heating element zones. did. And the sample of which the diameter of the circle C of the four outermost resistance heating element zones was 310 mm and the ratio of D1, D2, and D3 was changed was produced. After that, the plate-like ceramic body 2 was manufactured by brazing and fixing the feeding portion 6 to the resistance heating element 5.

  For comparison, a resistance heating element zone having the configuration shown in FIG. 9 is used, the size of the rectangular heating element zone is 212 × 53 mm, and sample No. 8 using eight rectangular heating element zones is used. 31 was produced. Similarly, sample no. Reference numeral 32 denotes a resistance heating element zone configured as shown in FIG. 8, wherein D1r is 150 mm and D2r is 310 mm. Sample No. Reference numeral 33 denotes the shape of the resistance heating element zone configured as shown in FIG. Sample No. A resistance heating element zone 34 was circular, and a wafer support member made of one resistance heating element was produced.

  The bottom of the bottomed metal case is made of 2.0mm of aluminum and 1.0mm of aluminum constituting the side wall, and the gas injection port, thermocouple, and conduction terminal are attached to the bottom of the case. It was. The distance from the bottom surface to the plate-like ceramic body was 20 mm.

  After that, a plate-shaped ceramic body is overlaid on the opening of the bottomed metal case, and a bolt is passed through the outer periphery thereof, so that the plate-shaped ceramic body and the bottomed metal case do not directly contact each other. A wafer support member was obtained by interposing a member and elastically fixing the member by screwing a nut through an elastic body from the contact member side.

  In addition, a wafer support member was produced with two structures, a support structure (1) for supporting the lower surface of the peripheral portion of the plate-shaped ceramic body and a support structure (2) for supporting the outer peripheral surface of the plate-shaped ceramic body. In the support structure (1), the diameter of the plate-like ceramic body is the same as the diameter that is the outer diameter of the metal case.

  The contact member 17 has a circular cross section and a ring shape. The size of the circular cross section was 1 mm in diameter. The material of the contact member was SUS304 or carbon steel. The prepared various wafer support members are sample Nos. 1-34.

  Evaluation of the produced wafer support member 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 support member, the wafer W is heated from 25 ° C. to 200 ° C. in 5 minutes, the temperature of the wafer W is set to 200 ° C., and then the average temperature of the wafer W is 200 ° C. ± 0.5 ° C. The time until it became constant in the range of was measured as the 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 the temperature difference of the wafer W.

Each result is as shown in Table 1.

  In the wafer support member 1 of the present invention, sample No. 1 having a circular resistance heating element zone in the center and resistance heating element zones in three concentric rings on the outer side thereof. The wafer support members 1 to 1 were excellent in that the temperature difference of the wafer W was less than 0.5 ° C. and the response time was 59 seconds or less. Further, the outer diameter D1 of the resistance heating element zone at the center is 15 to 40% of the outer diameter D of the outermost resistance heating element zone, and the outer diameter D2 is 40 to 60% of the outer diameter D. The wafer support member 1 whose diameter D3 is 60 to 85% of the outer diameter D is the sample No. 1 in Table 1. It was found that the temperature difference of the wafer W was as small as 0.45 ° C. or less and the response time was as small as 48 seconds or less, indicating excellent characteristics.

  Further, the outer diameter D1 of the resistance heating element zone at the center is 20 to 30% of the diameter D of the circle C of the resistance heating element. It was found that the wafer support members of 4 to 7 were excellent because the temperature difference of the wafer was as small as 0.31 ° C. or less and the response time was as small as 39 seconds or less. The outer diameter D1 is 22 to 26% of D. It was found that the wafer temperature difference between the wafer support members of 5 to 6 was as small as 0.22 ° C. or less, and the response time was as small as 37 seconds or less.

  The outer diameter D2 is 45 to 54% of D. It was found that the wafer support members 14 to 17 had a small wafer temperature difference of 0.35 ° C. or less and a response time of 36 seconds or less. The outer diameter D2 is 48 to 51% of D. It was found that with the wafer support members of 15 to 16, the temperature difference of the wafer was as small as 0.21 ° C. or less, and the response time was as small as 32 seconds or less, which was further preferable.

  The outer diameter D3 is 65 to 75% of D. It was found that the wafer support members of 24 to 27 were preferable because the temperature difference of the wafer was as small as 0.32 ° C. or less and the response time was as small as 35 seconds or less. The outer diameter D3 is 67 to 70% of D. It was found that the wafer support members of 25 to 26 have a smaller wafer temperature difference of 0.20 ° C. or less and a response time of 31 seconds or less, which is more preferable.

  A plate-like ceramic body was produced in the same manner as in Example 1.

  Then, the aluminum nitride sintered body is ground to produce a plurality of disk-shaped ceramic bodies 2 having a disk thickness of 3 mm and a diameter of 315 mm to 345 mm, and further penetrates three places evenly on a concentric circle of 60 mm from the center. A hole was formed. The through-hole diameter was 4 mm.

  Next, in order to deposit the resistance heating element 5 on the plate-like ceramic body 2, a conductor paste produced 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 printed in a predetermined pattern shape by a screen printing method, heated to 150 ° C. to dry the organic solvent, further degreased at 550 ° C. for 30 minutes, and then baked at a temperature of 700 to 900 ° C. Thus, the resistance heating element 5 having a thickness of 50 μm was formed. The pattern arrangement of the resistance heating element 5 is divided into a circle and an annular shape radially from the central portion, a pattern is formed in one circular shape in the central portion, and two patterns are formed in the outer annular portion. Four patterns are provided on the outer annular portion, and eight patterns are provided on the outermost periphery, for a total of 15 patterns. Then, the diameter of the circle C of the eight outermost patterns was set to 310 mm, and the diameter of the plate ceramic was changed. After that, the plate-like ceramic body 2 was manufactured by brazing and fixing the feeding portion 6 to the resistance heating element 5.

  Further, the bottom of the bottomed metal case is made of 2.0 mm aluminum and 1.0 mm thick aluminum constituting the side wall, and the gas injection port, the thermocouple, and the conduction terminal are arranged at predetermined positions on the bottom. Attached to. The distance from the bottom surface to the plate-like ceramic body was 20 mm.

  After that, a plate-shaped ceramic body is overlaid on the opening of the bottomed metal case, and a bolt is passed through the outer periphery thereof, so that the plate-shaped ceramic body and the bottomed metal case do not directly contact each other. A wafer support member was obtained by interposing a member and elastically fixing the member by screwing a nut through an elastic body from the contact member side.

  In addition, a wafer support member was produced with two structures, a support structure (1) for supporting the lower surface of the peripheral portion of the plate-shaped ceramic body and a support structure (2) for supporting the outer peripheral surface of the plate-shaped ceramic body. In the support structure (1), the diameter of the plate-shaped ceramic body is the same as the diameter of the metal case.

  The contact member 17 has a circular cross section and a ring shape. The size of the circular cross section was 1 mm in diameter. The material of the contact member was SUS304 or carbon steel. The prepared various wafer support members are sample Nos. 31-41.

  Evaluation of the produced wafer support member 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 support member, the wafer W is heated from 25 ° C. to 200 ° C. in 5 minutes, the temperature of the wafer W is set to 200 ° C., and then the average temperature of the wafer W is 200 ° C. ± 0.5 ° C. The time until it became constant in the range of was measured as the 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 the temperature difference of the wafer W.

Each result is as shown in Table 2.

  Sample No. in Table 2 In No. 35, the ratio of the diameter of the circle in contact with the resistance heating element to the diameter of the plate-like ceramic body was as small as 85%, the in-plane temperature difference of the wafer was as large as 0.48 ° C., and the response time was particularly large at 55 seconds.

  Sample No. 45, the ratio of the diameter of the circle in contact with the resistance heating element to the diameter of the plate-like ceramic body was 99.5%, the in-plane temperature difference of the wafer was as large as 1.02 ° C., and the response time was as large as 62 seconds, which was not preferable. .

  In contrast, sample no. 36 to 44 are excellent because the temperature difference in the plane of the wafer is as small as 0.22 ° C. or less and the response time is as small as 32 seconds or less. It can be seen that 90 to 99% of the ratio is an excellent wafer support member.

  Furthermore, in the support structure (1) connected to the lower surface of the outer peripheral portion of the plate-like ceramic body via a metal case and a contact member, the sample No. 37 to 39, the ratio of the diameter of the circle in contact with the resistance heating element to the diameter of the plate-like ceramic body is 92 to 95%, the in-plane temperature difference of the wafer is 0.19 ° C. or less, and the response time is 31 seconds. The following and better. In particular, sample no. 38 and 39 have an in-plane temperature difference of 0.17 ° C. or less and a response time of 30 seconds or less, so the ratio of the diameter of the circle in contact with the resistance heating element to the diameter of the plate-like ceramic body is 93 to 95%. And more preferable.

  On the other hand, in the support structure (2) connected to the metal case and the contact member on the outer peripheral side surface of the plate-shaped ceramic body, 40 to 43, the ratio of the diameter of the circle in contact with the resistance heating element to the diameter of the plate-like ceramic body is 95% to 98%, the in-plane temperature difference of the wafer is 0.21 ° C. or less, and the response time is 26 Excellent with less than a second. In particular, sample no. Since the in-plane temperature difference of 41 and 42 is both 0.19 ° C. or less and the response time is as small as 24 seconds or less, the ratio of the diameter of the circle in contact with the resistance heating element to the diameter of the plate-like ceramic body is 96% to 97 % Is more preferable.

  A plate-like ceramic body was produced in the same process as in Example 1. Then, a resistance heating element was printed on the main surface of the plate-like ceramic body in the same process as in Example 1. The pattern of the resistance heating element has the same configuration as that of the first embodiment. As a resistance heating element, a space S between the blank areas P having no arc-shaped pattern in a part of a circle in contact with the outermost eight patterns, and the resistance heating element A wafer support member was manufactured by changing the diameter of the plate-like ceramic body with the diameter of the contacting circle being 310 mm.

  In addition, a bottomed metal case made of aluminum was attached to the plate-like ceramic body via the contact member to produce a wafer support member.

And it evaluated similarly to Example 1. FIG. The results are shown in Table 3.

  Sample No. in which the difference L between the diameter of the plate-shaped ceramic body and the diameter of the circle in contact with the resistance heating element is larger than the space S between the blank areas. 51, 55, and 57 had wafer temperature differences of 0.44, 0.45, and 0.44 ° C., respectively, and response times of 35, 33, and 31 seconds were slightly large.

  In contrast, sample no. It was found that the blank space interval S of 52, 53, 54, 56, 58 is smaller than the difference L, the temperature difference of the wafer is 0.19 ° C. or less, and the response time is 25 seconds or less, showing excellent characteristics. .

  A plate-like ceramic body was produced in the same manner as in Example 1.

  However, the paste had a printed thickness of 20 μm, and a paste having a different ratio of the area occupied by the resistance heating element to a circle surrounding and contacting the resistance heating element was prepared.

And it evaluated similarly to Example 1. FIG. The results are shown in Table 4.

  As a result, sample no. As in 60, the sample in which the ratio of the area occupied by the resistance heating element to the circle surrounding and contacting the resistance heating element was less than 5% had a slightly large temperature difference of 0.35 ° C. in the wafer surface. Sample No. When the ratio of the area occupied by the resistance heating element exceeds 50% with respect to the circle surrounding and contacting the resistance heating element as in 69, a hot area having a high temperature appears in a part of the wafer, and the in-plane temperature difference of the wafer is increased. It was as large as 0.38 ° C.

  In contrast, sample no. As shown in 61 to 68, in the sample in which the ratio of the area occupied by the resistance heating element to the circle in contact with the resistance heating element is 5 to 50%, the in-plane temperature difference of the wafer is as small as 0.25 ° C. or less. Could be better.

  Sample No. Like 62-66, the ratio of the area which a resistance heating element occupies with respect to the circle which touches a resistance heating element shall be 10-30%, and the temperature difference in the surface of a wafer shall be less than 0.19 degreeC. In addition, sample no. As in 63 to 65, the ratio of the area occupied by the resistance heating element to the circumscribed circle of the resistance heating element is 15 to 25%, so that the temperature difference in the wafer surface is reduced to within 0.13 ° C. Can be particularly good.

It is sectional drawing which shows an example of the wafer heating apparatus of this invention. (A) (b) is the schematic which shows the shape of the resistance heating element zone of this invention. It is the schematic which shows the shape of the resistance heating element of this invention. It is the schematic which shows the shape of the other resistance heating element of this invention. It is sectional drawing which shows an example of the other wafer heating apparatus of this invention. It is sectional drawing which shows an example of the conventional wafer heating apparatus. It is the schematic which shows the shape of the conventional resistance heating element. It is the schematic which shows the shape of the other conventional resistance heating element. It is the schematic which shows the shape of the other conventional resistance heating element. It is the schematic which shows the shape of the other conventional resistance heating element.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 71: Wafer support member 2, 72: Plate-shaped ceramic body 3, 73: Mounting surface 5, 75: Resistance heating element 6: Power supply part 8: Support pin 11, 77: Power supply terminal 12: Guide member 16: Bolt 17: Contact member 18: Elastic body 19, 79: Metal case 20: Nut 21: Bottom 23: Hole 24: Gas injection port 25: Wafer lift pin 26: Through hole 27: Thermocouple 28: Guide member W: Semiconductor wafer

Claims (6)

A wafer supporting member having a plurality of resistance heating element zones on one main surface of a plate-shaped ceramic body and a mounting surface on which a wafer is placed on the other main surface, the resistance heating element in the resistance heating element zone A power supply section that supplies power independently, and a metal case that surrounds the power supply section, which is fixed via a ring-shaped contact member having a thermal conductivity smaller than that of the plate-like ceramic body, The metal case is provided with a gas injection port for cooling the plate-like ceramic body, and the resistance heating element zone includes a circular resistance heating element zone provided at the center and a concentric circle outside the circular resistance heating element zone. The outermost resistance heating element zone is composed of a plurality of outermost arc-shaped patterns divided in the circumferential direction and a continuous connection to the arc-shaped pattern. Pattern and be equipped , The spacing between the arc-like pattern, the wafer support member and is smaller than the difference between the outer diameter of the resistance heating element zone diameter and the outermost of the plate-like ceramic body. A wafer supporting member having a plurality of resistance heating element zones on one main surface of a plate-shaped ceramic body and a mounting surface on which a wafer is placed on the other main surface, the resistance heating element in the resistance heating element zone A power supply section that supplies power independently, and a metal case that surrounds the power supply section, which is fixed via a ring-shaped contact member having a thermal conductivity smaller than that of the plate-like ceramic body, The plate-like ceramic body and the metal case are interposed directly through the contact member, and the resistance heating element zone includes a circular resistance heating element zone provided at the center, and the circular resistance heating element. It is composed of three annular resistance heating element zones that are concentric outside the zone, and the outermost resistance heating element zone is continuous with a plurality of outermost arc-shaped patterns divided in the circumferential direction and the arc-shaped pattern. Shi A wafer support member, wherein a distance between the arc-shaped patterns is smaller than a difference between a diameter of the plate-shaped ceramic body and an outer diameter of the outermost resistance heating element zone. . The outer diameter D1 of the central resistance heating element zone is 15-40% of the outer diameter D of the outermost resistance heating element zone, and the outer resistance heating element zone next to the central resistance heating element zone. The outer diameter D2 is 40 to 60% of the outer diameter D, and the inner diameter D3 of the outermost resistance heating element zone is 60 to 85% of the outer diameter D of the outermost resistance heating element zone. The wafer support member according to claim 1. The diameter of a circle surrounding all the resistance heating elements in the resistance heating element zone and in contact with the plurality of resistance heating elements is 90 to 99% of the diameter of the plate-like ceramic body. The wafer support member in any one. 5. The wafer support member according to claim 1, wherein the ratio of the area of the resistance heating element in the circle is 5 to 50% with respect to the area of the circle. The wafer support member according to claim 1, wherein a cross section of the contact member is circular.

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