JP4051305B2 - Wafer support member - Google Patents

Description

【００５６】
表１からわかるように、板状セラミックス体３２を支持体４１に直接ネジ締めした試料Ｎｏ．３は、ウェハ面内の昇温時の過渡温度バラツキが１２．５℃と大きくなる。また、１５０℃キープ時の温度バラツキも１℃を越えてしまい好ましくない。これに対し、板状セラミックス体５２を弾性体５８を介して支持体６１にネジ締めしてある試料Ｎｏ．２は、ウェハＷ面内の昇温時の過渡温度バラツキが１０．５℃と大きかった。
【００５７】
これらに対し、本発明実施例であるＮｏ．１では、ウェハ面内の過渡温度バラツキ、保持温度バラツキのいずれも小さかった。これは有底の支持体よりも支柱で板状セラミックス体を支持した本発明のウェハ支持部材の方が、支持体と支柱との熱容量が小さい為、温度追従性が良い事に起因している。
【００５８】
（実施例２）
ここでは板状セラミックス体２の支柱２５への弾性体１８による押圧力の合計がウェハの温度分布に与える影響を調べた。
【００５９】
弾性体としてコイルバネを用いて、その押圧力の合計を１、２、１０、４０、７２，８２、９０、１００，１５０Ｎとなるように調整して、温度分布に与える影響を確認した。
【００６０】
なお板状セラミックス体２の弾性体１８による支柱への押圧力は、図２において、ナットの締込量を調整することで変化させた。
【００６１】
【表２】

【００６２】
表２からわかるように、押圧力の合計が２Ｎ〜１００Ｎの試料Ｎｏ．２２〜２８は、ウェハ面内の昇温時の過渡温度バラツキは６℃以下および１５０℃キープ時の保持温度バラツキも０．５℃以下となっている。
【００６３】
押圧力の合計が上記の条件のウェハ支持部材においては、全てウェハ面内の温度バラツキを抑えることができる。中でも押圧力の合計が４０〜１００Ｎの試料Ｎｏ．２４〜２８において、ウェハ面内の昇温時の過渡温度バラツキは５℃以下および１５０℃キープ時の保持温度バラツキも０．４℃以下となっており、レジスト膜形成において更に均一性が良好となることが分った。
【００６４】
（実施例３）
次に、板状セラミックス体２の支柱２５の数がウェハの温度分布に与える影響を調べた。
【００６５】
支柱の数を２、３、５、８、１２、１６、２０個として、板状セラミックス体２を支持して、それぞれ温度分布に与える影響を確認した。
【００６６】
なお板状セラミックス体２への支柱２５の弾性体１８による押圧力の合計は７０Ｎとした。
【００６７】
【表３】

【００６８】
表３からわかるように、支柱２５の数が３〜１６個であれば、ウェハ面内の過渡温度バラツキを５℃以内に抑えることができる。
【００６９】
しかし、支柱の数が２である試料Ｎｏ．３０は、板状セラミックス体２を二点で支持することから、板状セラミックス体の平坦度が大きく、ウェハ面内の過渡温度バラツキが７．２℃と大きくなった。
【００７０】
また、支柱の数が２０個の試料Ｎｏ．３６においては、支柱が多い為、熱容量が大きくなり、ウェハ面内の過渡温度バラツキが６．５℃と大きくなった。
【００７１】
【発明の効果】
以上のように、本発明によれば、板状セラミックス体の一方の主面をウェハを載せる載置面とし、他方の主面あるいは内部に抵抗発熱体を備えるとともに、前記抵抗発熱体に電力を供給する給電部と、該給電部を覆う支持体を備え、該支持体と板状セラミックス体とは複数の支柱を介して接合していると共に、該支柱は前記板状セラミックス体を支持する一方の端部を備えた円柱状の支持部と該支持部の他方の端部を支える補強部とからなり、該補強部の端部が前記支持体に固定され、前記板状セラミックス体と前記支持部と前記補強部とを貫通する貫通孔にボルトが挿入され、該ボルトの一方の端部が板状セラミックス体を押さえ、前記ボルトの他方の端部に固定されたナットと前記ボルトと前記補強部とで、前記ボルトが貫通して前記ナットと前記補強材との間に挟まれて保持された弾性体を有するウェハ支持部材を構成することで、支持体の反りが板状セラミックス体に反映されることを防止し、ウェハの昇温過渡時および定温保持時のウェハ面内の温度バラツキを抑制し、ウェハに良好な膜が形成されるようにすることができる。
【図面の簡単な説明】
【図１】（ａ）は本発明のウェハ支持部材を示す斜視図であり、（ｂ）はその断面図である。
【図２】本発明のウェハ支持部材の拡大断面図である。
【図３】本発明の他のウェハ支持部材の拡大断面図である。
【図４】本発明のウェハ支持部材を装置に取り付けた時の断面図である。
【図５】従来のウェハ支持部材を示す断面図である。
【図６】従来のウェハ支持部材を示す断面図である。
【符号の説明】
Ｗ：ウェハ
１、３１、５１：ウェハ支持部材
２、３２、５２：板状セラミックス体
３、３３、５３：載置面
４：支持体
５：抵抗発熱体
６：給電部
７：絶縁層
８：支持ピン
１０：測温素子
１１：導通端子
１６：ボルト
１８：弾性体
２０：ナット
２１：ボルト
２２：ナット
２４：サポートリング
２５：支柱
２６：補強部
２７：支持部[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a wafer support member mainly used for heating a wafer. For example, a semiconductor thin film is formed on a wafer such as a semiconductor wafer, a liquid crystal substrate, or a circuit substrate, or applied to the wafer. It is suitable for forming a resist film by drying and baking a resist solution.
[0002]
[Prior art]
For example, a wafer support member is used to heat a semiconductor wafer (hereinafter abbreviated as “wafer”) 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. Yes.
[0003]
Conventional semiconductor manufacturing equipment used batch-type processing that forms a plurality of wafers at once. To increase the processing speed as the wafer size increases from 8 inches to 12 inches, In recent years, a method called single wafer processing for processing one sheet at a time has been implemented. However, since the number of wafers processed at one time is reduced in the single wafer type, it is necessary to shorten the wafer processing time. For this reason, the wafer support member has been required to improve the accuracy of the heating temperature at the same time as shortening the wafer heating time and accelerating the desorption.
[0004]
In forming the resist film on the wafer, one main surface of the plate-like ceramic body 32 made of ceramics such as silicon carbide, aluminum nitride, or alumina as shown in FIG. 5 is used as a mounting surface 33 on which the wafer W is placed. On the other main surface, a resistance heating element 35 is installed via an insulating layer 34, and a conductive terminal 37 is fixed to the resistance heating element 35 by a brazing material layer (not shown), and a bottomed cylinder is formed so as to cover them. There has been proposed a wafer support member 31 having a structure including a support 41 having a shape. The plate-like ceramic body 32 is fixed to the support body 41 with bolts 47, and a thermocouple 40 is inserted into the plate-like ceramic body 32, whereby the temperature of the plate-like ceramic body 32 is set to a predetermined temperature. In order to maintain the power, the electric power supplied from the conductive terminal 37 to the resistance heating element 35 is adjusted. In addition, the conduction terminal 37 is fixed to the support body 41 via the insulating layer 39.
[0005]
Then, after the wafer W coated with the resist solution is placed on the placement surface 33 of the wafer support member 31, the resistance heating element 35 is heated to cause the wafer on the placement surface 33 via the plate-like ceramic body 32. W was heated and the resist solution was dried and baked to form a resist film on the wafer W.
[0006]
However, the wafer support member as described above has a structure in which the plate-like ceramic body 32 is fastened to the metal support body 41 with bolts 47 as shown in FIG. In order to form a resist film on the ceramic body 32, the support body 41 warps due to the temperature difference generated on the upper and lower surfaces of the support body 41 that occurs when the wafer W is placed, and the plate-like ceramic body 32 is fixed. There is a problem that stress concentrates on the bolts 47 and cracks occur in the plate-like ceramic body 32.
[0007]
Therefore, as a wafer support member that solves this problem, there is an example as in Patent Document 1. As shown in FIG. 6, the wafer support member 51 includes a bottomed support 61 and a plate-like ceramic body 52 as main components. A feature of the wafer support member 51 is that the outer peripheral portion of the plate-like ceramic body 52 is pressed and fixed to the metal support 61 by an elastic body 58. Thereby, even if the support 61 is deformed when the temperature of the plate-like ceramic body 52 fluctuates, this is absorbed by the elastic body 58, thereby preventing the warpage of the plate-like ceramic body 52 and the wafer. Temperature distribution was prevented from occurring on the surface of the wafer W during W heating.
[0008]
Patent Documents 1 and 2 disclose a wafer support member having a plate-like ceramic body provided with support pins. The wafer support member supports the wafer W with support pins so as to reduce a temperature difference in the wafer W surface at a certain distance from the mounting surface.
[0009]
[Patent Document 1] Japanese Patent Application No. 2001-210450
[Patent Document 2] JP 2002-359172 A
[Patent Document 3] Japanese Patent Application No. 2002-198417
[0010]
[Problems to be solved by the invention]
However, the wafer support member as described above has a structure in which the plate-like ceramic body 52 is supported by the bottomed support body 61 as shown in FIG. There is a problem that the temperature difference in the wafer surface is large in rapid heating.
[0011]
In addition, the in-plane temperature difference on the surface of the wafer W during the transition in which the wafer W at room temperature is heated on the plate-like ceramic body 52 heated to a predetermined temperature is large, and uniformity in film formation such as resist is impaired. There was a problem.
[0012]
[Means for Solving the Problems]
As a result of the present inventors diligently studying the above problems, the wafer support member of the present invention has one main surface of the plate-shaped ceramic body as a mounting surface on which the wafer is placed, and a resistance heating element on the other main surface or inside. In addition, a power supply unit that supplies power to the resistance heating element and a support that covers the power supply unit, the support and the plate-like ceramic body are joined via a plurality of support columns. Consists of a columnar support portion having one end portion for supporting the plate-shaped ceramic body and a reinforcement portion supporting the other end portion of the support portion, and the end portion of the reinforcement portion is fixed to the support body. A bolt is inserted into a through-hole penetrating the plate-shaped ceramic body, the support portion, and the reinforcing portion, and one end of the bolt holds the plate-shaped ceramic body, and the other end of the bolt A fixed nut and the bolt In between the reinforcement part and The bolt penetrates and is sandwiched between the nut and the reinforcing material It has the elastic body hold | maintained, It is characterized by the above-mentioned.
[0013]
In addition, the reinforcing part is The cross-sectional shape is composed of a horizontally long portion that supports the other end portion of the support portion and a vertical portion that is positioned at both ends of the horizontally long portion and is fixed to the support body. Portal shape or It consists of the said horizontally long part and the vertical part located in the end of this horizontally long part, and being fixed to the said support body It is any one of L-shaped shapes.
[0014]
Furthermore, the total pressing force for pressing the plate-like ceramic body by the elastic body against the support is 2 to 100 N. Moreover, 3-16 said support | pillars were provided.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described.
[0016]
FIG. 1A is a perspective view showing an example of a wafer support member according to the present invention, and FIG. 1B is a cross-sectional view taken along line AA of FIG. One main surface of the plate-like ceramic body 2 made of ceramics mainly composed of silicon carbide, boron carbide, boron nitride, silicon nitride, and aluminum nitride is used as the mounting surface 3 on which the wafer W is placed, and the other main surface. The resistance heating element 5 is formed through an insulating layer 7 made of glass or resin.
[0017]
Further, the mounting surface 3 includes support pins 8 that support the wafer W, and the support pins 8 support the wafer W so that the wafer W can be indirectly heated.
[0018]
As a pattern of the resistance heating element 5, a pattern shape capable of uniformly heating the mounting surface 3, such as a substantially concentric or spiral shape composed of an arc-shaped strip electrode portion and a straight strip electrode portion. If it is good. In order to improve the thermal uniformity, it is preferable to divide the resistance heating element 5 into a plurality of patterns. The resistance heating element 5 can be made of gold, silver, palladium, platinum group metal, or high melting point metal such as tungsten or nickel.
[0019]
In addition, the resistance heating element 5 is formed with a power feeding portion 6 made of a material such as gold, silver, palladium, or platinum, and the conduction terminal 11 is pressed and brought into contact with the power feeding portion 6 to ensure conduction.
[0020]
In the wafer support member 1 of the present invention, the support 4 that covers the power feeding unit 6 is joined to the plate-like ceramic body 2 via a plurality of support columns 25.
[0021]
The support of the plate-like ceramic body 2 by the plurality of support columns 25 is because the volume of the support columns 25 can be reduced as compared with the bottomed cylindrical support members 41 and 61. 25 and the support 4 are small in heat capacity, and the weight is advantageously reduced. Since the heat capacity can be reduced by supporting the plate-like ceramic body 2 by the plurality of support columns 25, the temperature followability in the wafer W surface is excellent during rapid heating, and the temperature difference in the wafer W surface is reduced. As a result, the temperature difference on the surface of the wafer W becomes small during the transient state when the wafer W at room temperature is placed on the plate-like ceramic body 2 heated to a predetermined temperature and heated rapidly, and the film quality is uniform in forming a film such as a resist. A product with excellent properties can be obtained.
[0022]
FIG. 2 is a sectional view taken along line BB in FIG. The support column 25 has a portal shape including a support portion 27 that supports the plate-like ceramic body 2 and a reinforcing portion 26 for obtaining the pressing force.
[0023]
The plate-like ceramic body 2 is pressed and elastically joined to the plurality of support posts 25 using an elastic body 18 made of a coil spring. That is, the elastic body 18 and the nut 20 for holding the elastic body 18 are fixed to the tip of the bolt 16 inserted through the support column 25. For example, when the support body 4 is thermally deformed, the plate-like ceramic body 2 is removed from the support column 25. By floating, the warp of the plate-like ceramic body 2 due to thermal deformation of the metal support 4 can be reduced. As described above, since the effect of suppressing the warpage of the plate-like ceramic body 2 is great and the change in the distance between the wafer W and the mounting surface 3 can be minimized, the increase in the in-plane temperature difference of the wafer W can be prevented. And a good resist film can be formed.
[0024]
The shape of the support 25 may be an L-shape as shown in FIG.
[0025]
FIG. 4 is a cross-sectional view showing a part of the mounting base and the wafer support member 1 when the wafer support member 1 of the present invention is incorporated in a semiconductor device.
[0026]
The wafer support member 1 in which the support 4 and the plate-shaped ceramic body 2 are joined via a plurality of support columns 25 is screwed to a ring-shaped support ring 24 by bolts 21 and nuts 22 when incorporated in a semiconductor device. The Here, the surface on which the support body 4 is fastened to the support ring 24 and the surface on which the support ring 24 is fastened to the support body 4 are ordinary machined surfaces, and are several tens of μm flat with respect to a diameter of 200 mm or 300 mm. There is a difference in degree, and when the support body 4 is fastened to the support ring 24, the support body 4 is deformed by several tens of μm along the fastening surface of the support ring 24. However, even if the support 4 is deformed, the support 25 and the plate-like ceramic body 2 fastened to the support 4 are elastically fixed by the spring, so that the distortion of the support 4 is absorbed by the elastic body 18. Further, it is possible to prevent the plate-like ceramic body 2 from being deformed to a size of several μm and to reduce the variation in the in-plane temperature difference of the wafer W.
[0027]
Further, even if the temperature of the plate-like ceramic body 2 is changed, or the set temperature of the plate-like ceramic body 2 is changed by placing the wafer W on the mounting surface 3 and the support body 4 is deformed, the elastic body 18 absorbs this. Thus, warpage of the plate-like ceramic body 2 can be prevented. As a result, the distance between the plate-shaped ceramic body 2 and the wafer W can be kept constant, and temperature distribution on the wafer surface during the wafer W heating can be prevented.
[0028]
Moreover, it is preferable that the total pressing force for pressing the plate-like ceramic body 2 against the support column 25 with these elastic bodies 18 is 2 to 100N. If the total pressing force is less than 2N, the pressing force of the plate-like ceramic body 2 to the support column 25 is small, so that the plate-like ceramic body 2 vibrates due to the impact or vibration generated when the wafer is placed on the plate-like ceramic body 2. However, the in-plane temperature difference of the wafer W may change.
[0029]
When the total pressing force exceeds 100 N, when the support body 4 is deformed, the pressing force of the plate-like ceramic body 2 and the support column 25 causes the plate-like ceramic body 2 to be deformed at a micron level, and the flatness of the plate-like ceramic body 2 is increased. The degree will get worse. In particular, management of the plate-like ceramic body 2 at the micron level is necessary to achieve the temperature variation of 1.0 ° C. or less in the wafer W surface currently required. Therefore, if the total pressing force exceeds 100 N, the distance between the plate-like ceramic body 2 and the wafer cannot be kept constant, and the temperature difference on the wafer surface may increase.
[0030]
Furthermore, it is more preferable that the total pressing force is 40 to 100N. By suppressing the total of the pressing forces within the above range, the warpage of the outermost peripheral portion of the plate-like ceramic body 2 can be suppressed within 20 μm. As a result, the distance between the plate-shaped ceramic body 2 and the wafer W can be made more uniform, the temperature distribution on the surface of the wafer W can be made uniform, and the film formation of the wafer resist film can be made uniform.
[0031]
Moreover, it is preferable to use a wafer support member having 3 to 16 support columns 25 for supporting the plate-like ceramic body 2. If the number of the support columns 25 is less than 3, the heat capacity becomes small, but the number of support of the plate-like ceramic body 2 becomes two points, which is not preferable because the flatness of the plate-like ceramic body 2 becomes large. On the other hand, if the number of the support columns 25 is more than 16, the plate-like ceramic body 2 is supported at a large number of points, and the heat capacity is increased. Therefore, the transient temperature variation in the wafer surface is large during rapid heating. Na There is a risk.
[0032]
The plate-like ceramic body 2 is formed of a silicon carbide sintered body, a boron carbide sintered body, a boron nitride sintered body, a silicon nitride sintered body, or an aluminum nitride sintered body. Since the deformation is small even when heat is applied and the plate thickness can be reduced, the heating time until heating to a predetermined processing temperature and the cooling time until cooling from the predetermined processing temperature to room temperature can be shortened. The productivity can be increased and the thermal conductivity is 60 W / (m · K) or more, so that the Joule heat of the resistance heating element 5 is quickly transmitted and the temperature variation of the mounting surface 3 is extremely reduced. be able to. In addition, since it does not generate gas by reacting with moisture in the atmosphere, even if it is used for attaching a resist film on the semiconductor wafer W, it does not adversely affect the structure of the resist film, and is fine. Wiring can be formed with high density.
[0033]
The silicon carbide sintered body includes a sintered body containing boron (B) and carbon (C) as sintering aids for silicon carbide as a main component, and a sintering aid for silicon carbide as a main component. Alumina (Al ₂ O ₃ ) And Yttria (Y ₂ O ₃ ) And sintered at 1900 to 2200 ° C., and silicon carbide may be either α-type or β-type.
[0034]
Moreover, as a boron carbide sintered body, 3 to 10% by weight of carbon as a sintering aid is mixed with boron carbide as a main component, and hot press firing is performed at 2000 to 2200 ° C. to obtain a sintered body. Can do.
[0035]
As the boron nitride sintered body, 30 to 45% by weight of aluminum nitride and 5 to 10% by weight of rare earth oxide are mixed as a sintering aid with the main component boron nitride, and hot at 1900 to 2100 ° C. A sintered body can be obtained by press firing. As another method for obtaining a sintered body of boron nitride, there is a method in which borosilicate glass is mixed and sintered, but this is not preferable because the thermal conductivity is remarkably lowered.
[0036]
As the silicon nitride sintered body, 3 to 12% by weight of rare earth element oxide and 0.5 to 3% by weight of Al as a sintering aid with respect to silicon nitride as a main component. ₂ O ₃ Furthermore, SiO contained in the sintered body ₂ SiO in an amount of 1.5 to 5% by weight ₂ Can be mixed and subjected to hot press firing at 1650 to 1750 ° C. to obtain a sintered body. SiO shown here ₂ The amount is SiO as an impurity contained in the silicon nitride raw material. ₂ And intentionally added SiO ₂ Is the sum of
[0037]
Moreover, as an aluminum nitride sintered body, Y as a sintering aid is used for the main component aluminum nitride. ₂ O ₃ And Yb ₂ O ₃ It is obtained by adding rare earth element oxides such as CaO and alkaline earth metal oxides such as CaO as necessary, mixing well, processing on a flat plate, and firing in nitrogen gas at 1900-2100 ° C. .
[0038]
The sintered body constituting the plate-like ceramic body 2 is used by selecting a material depending on its use. For example, when used for drying a resist film, a nitride reacts with moisture to generate ammonia gas, which cannot be used because it adversely affects the resist film. Further, in the case of a CVD wafer support member that may be used at a high temperature of about 800 ° C., the boron nitride-based material containing a large amount of glass is deformed during use so that the plate-like ceramic body 2 is deformed. May be damaged.
[0039]
Furthermore, the main surface opposite to the mounting surface 3 of the plate-like 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 7 made of glass or resin. The thickness (Ra) is preferably polished to 0.1 μm to 0.5 μm.
[0040]
On the other hand, when the silicon carbide sintered body is used as the plate-like ceramic body 2, the insulating layer 7 that maintains insulation between the plate-like ceramic body 2 and the resistance heating element 5 having a certain conductivity is made of glass or resin. 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 350 μm, the plate-shaped ceramic body 2 is formed. Since the thermal expansion difference between the silicon carbide sintered body and the aluminum nitride sintered body is too large, cracks are generated and the insulating layer 7 does not function. Therefore, when glass is used as the insulating layer 7, the thickness of the insulating layer 7 is preferably formed in the range of 100 μm to 350 μm, and more preferably in the range of 200 to 350 μm.
[0041]
Further, in the case where the plate-like ceramic body 2 is formed of a ceramic sintered body mainly composed of aluminum nitride, in order to improve the adhesion of the resistance heating element 5 to the plate-like ceramic body 2, an insulating material made of glass. Layer 7 is formed. However, when sufficient glass is added in the resistance heating element 5 and sufficient adhesion strength is obtained by this, it can be omitted.
[0042]
As a means for depositing the insulating layer 7 made of glass on the plate-like ceramic body 2, the glass paste is uniformly applied by a screen printing method, a dipping method, a spray coating method or the like, and then 800 to 1000 ° C. Bake at a temperature of. When glass is used as the insulating layer 7, a soaking plate made of a silicon carbide sintered body or a boron carbide sintered body is heated to a temperature of about 1200 ° C. in advance, and the surface on which the insulating layer 7 is to be deposited is formed. By performing the oxidation treatment, the adhesion with the insulating layer 7 made of glass can be enhanced.
[0043]
Furthermore, as the resistance heating element 5 deposited on the insulating layer 7, a metal such as gold (Au), silver (Ag), copper (Cu), palladium (Pd), platinum group metal, or rhenium oxide (Re ₂ O ₃ ), Lanthanum manganate (LaMnO) ₃ Prepare a glass paste containing one or more of the conductive oxides as a conductive material, print it in a predetermined pattern shape by screen printing, etc., and bake it to bond the conductive material with a matrix made of glass. It ’s fine. 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.
[0044]
However, when silver or copper is used for the resistance heating element 5, migration occurs. fear Therefore, in such a case, a protective film made of the same material as the insulating layer 7 may be covered with a thickness of about 30 μm so as to cover the resistance heating element 5.
[0045]
The glass for forming the insulating layer 7 may be either crystalline or amorphous. For example, when used for resist drying, the thermal resistance is 200 ° C. or higher and the thermal expansion in the temperature range of 0 ° C. to 200 ° C. The coefficient is −5 to + 5 × 10 with respect to the thermal expansion coefficient of the ceramic constituting the plate-like ceramic body 2. ^-7 It is preferable to select and use one in the range of / ° 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 ceramic body 2 becomes too large. This is because warpage is likely to occur and defects such as cracks and peeling are likely to occur.
[0046]
【Example】
Example 1
Examples of the present invention will be described below.
[0047]
A silicon carbide sintered body having a thermal conductivity of 80 W / (m · K) is ground to produce a plurality of disk-shaped ceramic plates having a plate thickness of 4 mm and an outer diameter of 300 mm. In order to adhere the insulating layer 7 to the main surface, a glass paste prepared by kneading ethyl cellulose as a binder and terpineol as an organic solvent to a glass powder is laid by screen printing and heated at 150 ° C. After the organic solvent was dried, degreasing treatment was performed at 550 ° C. for 30 minutes, and baking was performed at a temperature of 700 to 900 ° C., thereby forming an insulating layer 7 made of glass having a thickness of 200 μm. Next, in order to deposit the resistance heating element 5 on the insulating layer 7, a glass paste to which Au powder and Pt powder are added as a conductive material is printed in a predetermined pattern shape by a screen printing method, and then heated to 150 ° C. The organic solvent was dried, and after degreasing at 550 ° C. for 30 minutes, baking was performed at a temperature of 700 to 900 ° C. to form a resistance heating element 5 having a thickness of 50 μm. The resistance heating element 5 has a five-pattern configuration in which a circular central portion and an outer peripheral portion are divided into four in the circumferential direction. After that, the plate-like ceramic body 2 was manufactured by fixing the power supply portion 6 containing Au to the resistance heating element 5 using a conductive adhesive.
[0048]
Further, a support 4 made of SUS304 having a thickness of 2.5 mm with an opening formed in 30% of the main surface was prepared, and the thermocouple 10 and the ten conduction terminals 11 were formed at predetermined positions.
[0049]
Thereafter, the plate-like ceramic body 2 is overlaid on the support column 25 fastened to the support body 4, and the outer peripheral portion thereof is fixed via the elastic body 18, thereby obtaining the wafer support member 1 of the present invention shown in FIG. (No. 1 in Table 1).
[0050]
Further, as shown in FIG. 5, a wafer support member 31 in which the plate-like ceramic body 32 made of silicon carbide is screwed to a support 41 at eight locations is used as a sample for comparison. It was set to 3.
[0051]
Further, as shown in FIG. 6, a wafer support member 51 in which the plate-like ceramic body 52 made of silicon carbide is screwed to a support 51 at eight positions is used as a sample for comparison. 2.
[0052]
The conductive terminals 11, 37, and 57 of the three types of wafer support members 1, 31, and 51 thus obtained were energized and held at 150 ° C. for 30 minutes. Then, the temperature distribution of the wafer surface placed on the placement surfaces 3, 33, 53 is measured and the holding temperature is measured by measuring the temperature variation of a total of 7 points including 6 division points on the circumference of the center and a half of the wafer radius. It was uneven. Thereafter, the wafer is removed without changing the energization state, and the maximum value of the temperature variation in the wafer surface at the time of transition until the wafer W is held at 150 ° C. after 20 minutes is placed on each sample is 5 for each sample. The maximum value was taken as the transient temperature variation.
[0053]
As evaluation criteria, the resist film formation was uniform when the temperature variation on the wafer surface was within 10 ° C., and the resist film formation was non-uniform when the temperature was higher. Further, regarding the holding temperature variation at the time of the temperature keeping, the resist film formation was uniform within 1 ° C., and the resist film formation was non-uniform when exceeding this.
[0054]
Each result is as shown in Table 1.
[0055]
[Table 1]

[0056]
As can be seen from Table 1, sample No. 1 was obtained by screwing the plate-like ceramic body 32 directly to the support 41. No. 3 has a transient temperature variation of 12.5 ° C. at the time of temperature rise in the wafer surface. Moreover, the temperature variation at the time of 150 degreeC keeps exceeding 1 degreeC, and is not preferable. On the other hand, the sample ceramics 52 in which the plate-like ceramic body 52 is screwed to the support body 61 via the elastic body 58. No. 2 had a large transient temperature variation of 10.5 ° C. during the temperature rise in the wafer W plane.
[0057]
On the other hand, No. which is an embodiment of the present invention. In No. 1, both the transient temperature variation and the holding temperature variation in the wafer surface were small. This is because the wafer support member of the present invention in which the plate-like ceramic body is supported by the support column has a lower temperature capacity between the support member and the support column than the bottomed support member, and thus has better temperature followability. .
[0058]
(Example 2)
Here, the influence of the total pressing force of the elastic body 18 on the support 25 of the plate-like ceramic body 2 on the temperature distribution of the wafer was examined.
[0059]
Using a coil spring as an elastic body, the total pressing force was adjusted to 1, 2, 10, 40, 72, 82, 90, 100, and 150 N, and the influence on the temperature distribution was confirmed.
[0060]
In addition, the pressing force to the support | pillar by the elastic body 18 of the plate-shaped ceramic body 2 was changed by adjusting the tightening amount of a nut in FIG.
[0061]
[Table 2]

[0062]
As can be seen from Table 2, sample Nos. With a total pressing force of 2N to 100N. In Nos. 22 to 28, the transient temperature variation at the time of temperature rise in the wafer surface is 6 ° C. or less, and the holding temperature variation at the 150 ° C. keep is also 0.5 ° C. or less.
[0063]
In the wafer support member in which the total pressing force is the above condition, temperature variations in the wafer surface can all be suppressed. Among them, the sample No. having a total pressing force of 40 to 100N. 24 to 28, the transient temperature variation at the time of temperature rise in the wafer surface is 5 ° C. or less, and the holding temperature variation at the time of 150 ° C. keep is 0.4 ° C. or less, which further improves the uniformity in resist film formation. I found out that
[0064]
(Example 3)
Next, the influence of the number of support posts 25 of the plate-like ceramic body 2 on the temperature distribution of the wafer was examined.
[0065]
The number of struts was 2, 3, 5, 8, 12, 16, and 20 to support the plate-like ceramic body 2 and confirm the influence on the temperature distribution.
[0066]
The total pressing force by the elastic body 18 of the support column 25 to the plate-like ceramic body 2 was 70N.
[0067]
[Table 3]

[0068]
As can be seen from Table 3, if the number of support columns 25 is 3 to 16, the variation in transient temperature within the wafer surface can be suppressed to within 5 ° C.
[0069]
However, sample no. Since No. 30 supports the plate-like ceramic body 2 at two points, the flatness of the plate-like ceramic body is large, and the transient temperature variation in the wafer surface is as large as 7.2 ° C.
[0070]
In addition, sample No. 20 with 20 struts was used. In 36, since there were many support | pillars, heat capacity became large and the transient temperature variation in a wafer surface became large with 6.5 degreeC.
[0071]
【The invention's effect】
As described above, according to the present invention, one main surface of the plate-shaped ceramic body is used as a mounting surface on which a wafer is placed, and a resistance heating element is provided on the other main surface or inside, and power is supplied to the resistance heating element. A power feeding unit to be supplied; and a support that covers the power feeding unit. The support and the plate-like ceramic body are joined to each other via a plurality of columns, and the columns support the plate-like ceramic body. And a reinforcing part that supports the other end of the supporting part, the end of the reinforcing part being fixed to the supporting body, and the plate-like ceramic body and the supporting part. A bolt is inserted into a through-hole penetrating the portion and the reinforcing portion, one end of the bolt holds the plate-like ceramic body, and the nut fixed to the other end of the bolt, the bolt, and the reinforcement In the department The bolt penetrates and is sandwiched between the nut and the reinforcing material By constituting a wafer support member having a held elastic body, it is possible to prevent the warp of the support body from being reflected in the plate-shaped ceramic body, and the temperature within the wafer surface during the temperature rise transient of the wafer and the constant temperature hold. Variations can be suppressed, and a good film can be formed on the wafer.
[Brief description of the drawings]
FIG. 1A is a perspective view showing a wafer support member of the present invention, and FIG. 1B is a cross-sectional view thereof.
FIG. 2 is an enlarged cross-sectional view of a wafer support member of the present invention.
FIG. 3 is an enlarged cross-sectional view of another wafer support member of the present invention.
FIG. 4 is a cross-sectional view when the wafer support member of the present invention is attached to the apparatus.
FIG. 5 is a cross-sectional view showing a conventional wafer support member.
FIG. 6 is a cross-sectional view showing a conventional wafer support member.
[Explanation of symbols]
W: Wafer
1, 31, 51: Wafer support member
2, 32, 52: Plate-shaped ceramic body
3, 33, 53: Placement surface
4: Support
5: Resistance heating element
6: Feeder
7: Insulating layer
8: Support pin
10: Temperature measuring element
11: Conduction terminal
16: Bolt
18: Elastic body
20: Nut
21: Bolt
22: Nut
24: Support ring
25: Prop
26 : Supplement Strong part
27 : Support Holding part

Claims (4)

One main surface of the plate-shaped ceramic body is used as a mounting surface on which a wafer is placed, a resistance heating element is provided on the other main surface or inside, and a power feeding unit that supplies power to the resistance heating body, and covers the power feeding unit A columnar support having a support, the support and the plate-shaped ceramic body being joined via a plurality of columns, and the column having one end for supporting the plate-shaped ceramic body And a reinforcing part that supports the other end of the support part, the end of the reinforcing part being fixed to the support, and penetrating through the plate-like ceramic body, the support part, and the reinforcement part A bolt is inserted into the hole, one end of the bolt holds the plate-shaped ceramic body, and the bolt passes through the nut, the bolt, and the reinforcing portion fixed to the other end of the bolt. Between the nut and the reinforcing material Wafer support member, characterized in that it has a Marete retained elastic body. The reinforcing part has a gate-like shape in which a cross-sectional shape includes a horizontally long part that supports the other end of the support part and a vertical part that is positioned at both ends of the horizontally long part and is fixed to the support body, or the horizontally long part. 2. The wafer support member according to claim 1, wherein the wafer support member has an L-shape that is positioned at one end of the horizontally long portion and a vertical portion fixed to the support.   3. The wafer support member according to claim 2, wherein a total pressing force of pressing the plate-like ceramic body by the elastic body against the support is 2 to 100 N. 4.   The wafer support member according to claim 1, wherein 3 to 16 of the support columns are provided.

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