JP4359927B2 - Wafer heating apparatus and manufacturing method thereof - 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 wafer, a liquid crystal device, or a circuit board, or a resist solution applied on the wafer is used. The present invention relates to a wafer heating apparatus suitable for forming a resist film by dry baking.

  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, a wafer heating apparatus for heating a semiconductor wafer (hereinafter abbreviated as a wafer) is used.

  Conventional semiconductor manufacturing apparatuses include a batch type that heats a plurality of wafers at once and a single-wafer type that heats one wafer at a time. The single-wafer type has excellent temperature controllability. As the miniaturization of wafers and the improvement of the accuracy of the wafer heat treatment temperature are required, single wafer type wafer heating apparatuses are widely used.

  As shown in FIG. 5, such a wafer heating device 71 includes a plate-like ceramic body 72 having a resistance heating element 75 as a main component, and is a plate-like ceramic made of nitride ceramic or carbide ceramic. The upper surface of the body 72 is used as a mounting surface 73 on which the wafer 90 is placed, and a concentric resistance heating element 75 as shown in FIG. 4 is provided on the lower surface of the plate-like ceramic body 72, for example.

  The plate-like ceramic body 72 can be rapidly cooled by blowing a cooling gas from the gas injection port 82 to the plate-like ceramic body 72.

  Further, such a wafer heating device 71 is easily affected by light heat, processing gas, and the like when the semiconductor manufacturing apparatus is used, so that durability against oxidation of the surface of the resistance heating element 75 is required. Therefore, in order to increase the durability of the resistance heating element 75, a part or all of the resistance heating element 75 is covered with the insulating layer 83 (see Patent Document 1).

Furthermore, since this insulating layer 83 can also be a heat insulating material for the resistance heating element 75, there is a case where the temperature of the wafer heating device 71 is raised and then cooled, and thus the temperature cannot be rapidly lowered. There has also been a wafer heating apparatus having a surface roughness Ra of 0.01 to 10 μm (see Patent Document 2).
JP 2001-297857 A JP 2001-297858 A

  However, in the plate-shaped ceramic body 72, the resistance heating element 75, and the insulating layer 83, due to the difference in mutual thermal expansion, the resistance heating element 75 and the insulating layer 83 of the plate-shaped ceramic body 72 are different from each other. The adhesion strength is weak, and in particular, when heating and cooling are repeated, or when the cooling gas is discharged from the nozzle 82, the resistance heating element 75 and the insulating layer 83 are peeled off and damage such as cracks occurs.

  That is, it is insufficient to protect the resistance heating element 75 simply by providing the insulating layer 83 in the entire region of the resistance heating element 75 provided on the plate-like ceramic body 72.

  Therefore, the present invention provides a highly reliable wafer heating apparatus that does not deteriorate in performance such as peeling of the resistance heating element 75 and the insulating layer 83 and generation of cracks even when the temperature is raised and lowered or the refrigerant is discharged. Objective.

In view of the prior SL, the present invention is to provide a mounting surface mounting the wafer one main surface of the ceramic plate, a wafer heating with one or two circuits or more resistance heating elements on the other major surface The resistance heating element has a ratio (tp / tv) × 100 of the thickness (tv) of the concave portion and the thickness (tp) of the convex portion of the surface of the resistance heating element of 105 to 200%. It is characterized by being an uneven surface with an average thickness of 3 to 60 μm .

Also includes an insulating layer covering a part or all of the pre-Symbol resistance heating element, the surface of the insulating layer, the ratio of the concave portion of the thickness of the (tv) and the thickness of the convex portion (tp) (tp / tv) × 100 is 105 to 200%, and the insulating layer has an uneven surface with an average thickness of 3 to 60 μm .

Furthermore, a wafer heating apparatus having one main surface of the plate-like ceramic body as a mounting surface on which a wafer is placed and the other main surface having one or more resistance heating elements, the resistance heating element Is provided with an insulating layer covering a part or all of the resistance heating element, and the surface of the insulating layer is a ratio of the thickness (tv) of the concave portion to the thickness (tp) of the convex portion ( (tp / tv) × 100 is 105 to 200%, and the insulating layer has an uneven surface with an average thickness of 3 to 60 μm.

Moreover, the uneven surface is characterized by groove der Rukoto substantially lattice shape.

Moreover, the substantially lattice-shaped grooves, characterized that you have parallel with 0.2 to 80 lines per 1mm width.

  The resistance heating element is made of at least two kinds of metals selected from Pt, Au, and Ag and glass.

  The insulating layer is mainly composed of glass.

Also characterized in that it comprises means for cooling by blowing gas before Symbol uneven surface.

Also includes a power supply unit for supplying power independently to each of the resistance heating element, and a casing surrounding the power feeding section, a gas injection port for cooling the pre-Symbol ceramic plate in the case It is characterized by that.

Further, and forming an uneven surface before Symbol wafer heating apparatus by screen printing.

  In the wafer heating apparatus of the present invention, one main surface of the plate-like ceramic body is used as a mounting surface on which a wafer is placed, and one or more resistance heating elements and a part of the resistance heating element are provided on the other main surface. Or, by providing an insulating layer covering all of the surface and making the surface of the resistance heating element and / or the surface of the insulating layer uneven, it is possible to suppress the deterioration damage of the resistance heating element while absorbing the thermal expansion difference. A highly reliable wafer heating apparatus can be obtained.

Moreover, the uneven surface of the front Symbol resistance heating element and / or pre-Symbol insulating layer, a substantially lattice-like, the ratio of the concave portion of the thickness of the (tv) and the thickness of the convex portion (tp) (tp / tv) × 100 is 105 It was 200%, by and average thickness before Symbol resistance heating element or a pre-Symbol insulating layer has a 3～60Myuemu, the reliability of the wafer heating apparatus can be dramatically increased.

Further, it is possible to reduce the temperature of the plate-shaped ceramic body rapidly by prior Symbol uneven surface blow a cooling gas.

  The present invention relates to a wafer heating apparatus mainly used for heating a wafer.

FIG. 1 is a cross-sectional view showing an example of a wafer heating apparatus 1 according to the present invention. One main surface of a plate-like ceramic body 2 is used as a mounting surface 3 on which a wafer 90 is placed, and 1 is provided on the other main surface. or it comprises two circuits or more resistance heating elements 4 has an insulating layer 5 thereon as necessary. The resistance heating element 4 includes a power supply unit 6 that supplies power independently to each other, and includes a case 11 that surrounds the power supply unit 6.

  Further, the lift pins 10 are installed so as to be movable up and down, and the wafer 90 can be placed on the placement surface 3 or lifted from the placement surface 3.

  The bottom surface 21 of the case 11 is provided with a gas injection port 12 for injecting a cooling gas.

  The cooling gas injected from the gas injection port 12 is poured onto the lower surface of the plate-like ceramic body 2, depriving the heat of the lower surface of the plate-like ceramic body 2, and the heated cooling gas transfers heat to the enclosed case 11. However, the plate-shaped ceramic body 2 can be rapidly cooled by being discharged to the outside through the hole provided in the bottom surface 21 of the metal case 11.

  In order to heat the wafer 90 by the wafer heating apparatus 1, the wafer 90 carried to the upper side of the mounting surface 3 is supported by the lift pins 10 by a transfer arm (not shown), and then the lift pins 10 are lowered to lower the wafer 90. Is placed on the mounting surface 3.

  Next, the power supply unit 6 is energized to cause the resistance heating element 5 to generate heat, and the wafer 90 on the mounting surface 3 can be heated via the plate-like ceramic body 2.

  The wafer heating apparatus 1 of the present invention is characterized in that the surface of the resistance heating element 4 is an uneven surface 40.

It shows a schematic diagram of a prior SL uneven surface in FIG. 2.

  By forming the surface of the resistance heating element 4 to be a concavo-convex surface 40, when the resistance heating element 4 is energized to generate heat and the temperature rapidly rises, the resistance heating element 4 generates resistance heating due to a temperature difference from the plate-like ceramic body 2 and a difference in thermal expansion coefficient. Thermal stress is generated between the body 4 and the plate-shaped ceramic body 2, and there is a possibility that the resistance heating element 4 may be damaged due to generation of a large compressive stress in the resistance heating element 4. It has been found that stress can be relaxed.

  Although a large compressive stress is generated on the surface of the thermal stress, if the uneven surface 40 is formed, this stress can be received in a wide range of the uneven surface 40, and the surface stress can be dispersed over a wide surface. The resistance heating element 4 can be prevented from peeling and cracking due to stress. In particular, when the resistance heating element 4 is repeatedly heated and cooled, the stress is repeatedly applied to the resistance heating element 4. It was found that the repetitive life for the resistance heating element 4 is improved by the relaxation.

  Further, although the explanation has been made taking the uneven surface 40 on the surface of the resistance heating element 4 as an example, the same effect can be seen also in the wafer heating apparatus in which the insulating layer 5 is formed on the surface of the resistance heating element 4.

FIG. 3 is a perspective view showing another example of the wafer heating apparatus 1 according to the present invention, in which one main surface of the plate-like ceramic body 2 is a mounting surface 3 on which a wafer is placed, and the other main surface is irregularities and 1 or 2 circuit more resistance heating elements 4, a wafer heating apparatus 1 formed by including an insulating layer 5 that covers a part or all of the resistance heating body 4, the surface of the insulating layer 5 The surface 50 is preferable because there is no possibility of peeling or cracking in the resistance heating element 4 even if heating and cooling are repeated.

  The stress resulting from the temperature difference and the difference in thermal expansion is likely to appear on the surface of the insulating layer 5 which is the outer surface. However, if the surface is the uneven surface 50, the stress can be dispersed in the same manner as described above. The peeling of the body 4 and the occurrence of cracks can be prevented.

Further, as shown in FIGS. 2 and 3, the uneven surface 40 of the surface of the ceramic plate 2 of the resistance heating element 4 and / or pre-Symbol insulating layer 5, 50 has a large stress relaxation effect as a substantially grid-like preferable. It can be considered that the stress relaxation effect is exhibited because the stress is easily dispersed from front to back and from side to side in the lattice shape.

The front Symbol lattice-like grooves are 0.2 to 80 fibers per 1mm width, more preferably preferably be present 0.4 to 40. The groove is small, the effect of lower than the stress relaxation of 0.2 fibers per 1mm width, a repetition heating cooling the resistance heating element 4 resistance heating body 4 is cracking or peeling there is a risk or to occur.

The front Kimizo there is a possibility that crack 80 fibers per 1mm from the recess 42, 52 is too small to ultra El and grooves to the resistance heating body 4. Therefore, by making the groove of the concavo-convex surface 40 0.4 to 80 per 1 mm, the deterioration damage of the resistance heating element 4 can be suppressed while absorbing the difference in thermal expansion between the plate-like ceramic body 2 and the resistance heating element 4. Therefore, the highly reliable wafer heating apparatus 1 can be provided.

  At first glance, it seems as if the thickness of the insulating layer 5 should be increased in order to suppress the deterioration damage of the resistance heating element 4, but the insulating layer 5 serving as a protective layer is different from the resistance heating element 4. Since it is a material, the stress relaxation effect is weakened by the difference in mutual thermal expansion. That is, the insulating layer 5 that is too thick has an adverse effect, and a large stress acts on the insulating layer 5 when the insulating layer 5 is baked, which may reduce reliability. Therefore, in the present invention, the resistance heating element 4 and / or the insulating layer 5 of the plate-like ceramic body 2 is provided with an uneven surface, preferably approximately as a means for preventing deterioration of the resistance heating element 4 without increasing the thickness of the entire insulating layer 5. We found that the lattice shape is effective.

  That is, by forming the insulating layer 5 covering the resistance heating element 4 in a substantially lattice shape, the protrusions in the substantially lattice of the insulating layer 5 strongly suppress the resistance heating element 4 and cause the resistance heating element 4 to peel off. There is no.

  In addition, the entire insulating layer 5 is not thick, and stress due to the difference in thermal expansion is relieved in the recesses 52 in the substantially lattice, so that problems such as cracks do not occur. The same can be said for the plate-like ceramic body 2 and the resistance heating element 4, and it is preferable that the resistance heating element 4 itself has a substantially lattice shape.

The front Symbol of the uneven surface 40, 50, the ratio of the concave portion of the thickness of the (tv) and the thickness of the convex portion (tp) (tp / tv) × 100 is 105 to 200%, and pre-Symbol resistance heating element 4 or the average thickness before Symbol insulating layer 5 is Ru 3~60μm der. By doing so, the deterioration heating damage of the resistance heating element 4 can be suppressed while absorbing the difference in thermal expansion between the plate-like ceramic body 2 and the resistance heating element 4 in particular, and the highly reliable wafer heating apparatus 1 and can do.

  If the value of the ratio (tp / tv) × 100 is less than 105%, the heat exchange is bad and the number of temperature raising / lowering tests until cracks occur may be less than 4200, which is not preferable.

  Further, if the ratio value exceeds 200%, the difference between the convex portion 41 and the concave portion 42 is too large, the temperature difference becomes large, and there is a possibility that the number of temperature raising / lowering tests in which cracks occur is reduced.

  Further, if the resistance heating element 4 is formed by the printing method when the average thickness of the insulating layer 5 is less than 3 μm, the thickness variation is increased to 30% or more and the surface temperature difference of the wafer 90 may be increased.

  Further, when the average thickness of the insulating layer 5 exceeds 60 μm, there is a problem that minute cracks are likely to occur in the insulating layer 5 due to the difference in thermal expansion coefficient from the plate-like ceramic body 2.

In addition, the thickness (tv ) of a recessed part can be shown by the average value of five places of the center of each recessed part 42,52. The thickness of the convex portion (tp) can be determined as an average of maximum thickness 5 points of each convex section 41 and 51. Furthermore, the average thickness can be determined as an average value before Symbol thicknesses of the convex portions 41, 51 of the recesses 42 and 52.

  The resistance heating element 4 may be a composite material of at least two kinds of metals and glass selected from Pt, Au, and Ag. The reason for this is that since it is a noble metal, its oxidation resistance is essentially high, and matching with glass that holds these noble metals firmly is good.

  Preferably, the resistance heating element 4 made of Pt and Au and glass, or Pt and Ag and glass is preferable. Of these, glass made of the same component as the insulating layer 5 is more preferable. As a result, the fusibility between the resistance heating element 4 and the insulating layer 5 is enhanced, and it is possible to make it difficult for peeling and cracking to occur.

  Furthermore, the ratio of the composite material constituting the resistance heating element 4 is preferably Pt: Au: glass = 20 to 40:10 to 30:40 to 60% by mass, particularly preferably Pt: when Pt and Au are used. Au: Glass = 30: 20: 50% by mass is preferable.

  On the other hand, when Pt and Ag are used, Pt: Ag: Glass = 20 to 40:10 to 30:40 to 60% by mass is good, particularly preferably Pt: Ag: Glass = 30: 20: 50% by mass. Is good.

Note that the glass here is preferably a ZnO—B ₂ O ₃ —SiO ₂ —MnO ₂ -based crystallized glass mainly containing ZnO. Further, a glass having 50 to 70% by mass of ZnO, 20 to 30% by mass of B ₂ O _3, 5 to 20% by mass of SiO ₂ , and 1 to 3% by mass of MnO ₂ is preferable.

The insulating layer 5 is preferably composed mainly of glass, and in particular, ZnO—B ₂ O ₃ —SiO ₂ based crystallized glass composed mainly of ZnO. Further, a glass having 50 to 70% by mass of ZnO, 20 to 30% by mass of B ₂ O _3, 5 to 20% by mass of SiO ₂ , and 1 to 3% by mass of MnO ₂ is preferable. The crystallization temperature of this glass is about 740 ° C., and the thermal expansion coefficient is about 4 ppm / ° C. Therefore, the difference in thermal expansion from silicon carbide or aluminum nitride forming the plate-like ceramic body 2 is relatively small, and sufficient heat resistance can be obtained for the wafer heating apparatus 1 used at 300 ° C. or lower. The difference in thermal expansion between the resistance heating element 4 and the plate-like ceramic body 2 is 3.0 × 10 ⁻⁶ / ° C. or less. It is particularly preferable because it can be more easily absorbed.

However, other PbO—SiO ₂ , PbO—B ₂ O ₃ —SiO ₂ and PbO—ZnO—B ₂ O ₃ glasses mainly composed of PbO contain toxic Pb and have a crystallization temperature. Is not preferable because it is as low as 500 ° C. or less.

  In this way, one main surface of the plate-like ceramic body 2 is used as a mounting surface on which a wafer is placed, and one or more resistance heating elements 4 are formed on the other main surface. The wafer heating apparatus 1 provided with the insulating layer 5 having a shape for a part or all of the above can be obtained.

Then, before Symbol wafer heating apparatus 1, by heating the resistance heating element 4 can be heated wafer 90, but upon cooling cools stop energizing the resistance heating body 4, the cooling time of the gas injection port 12 air was injected as the cooling gas from the resistance heating element 4 and the plate-shaped ceramic body 2 is preferably cooled. And when this cooling gas is sprayed on the uneven surfaces 40 and 50, heat exchange is easily performed between the uneven surfaces 40 and 50 and the gas, and the plate-like ceramic body 2 can be efficiently cooled. found.

  Further, in forming the grid-like uneven surfaces 40 and 50 on the surface of the resistance heating element 4 and / or the insulating layer 5, a method of screen printing as a paste material for the resistance heating element 4 and / or the insulating layer 5 is used. Can be used. In other words, it may be formed using a plate making shape used for screen printing, or may be formed by processing by a transfer method or the like. Specifically, the resistance heating element 4 and / or the insulating layer 5 is made to have a paste having a viscosity of 3000 poise or more and printing is performed using a mesh-like plate making, and the substantially grid-like resistance heating element 4 and / or The insulating layer 5 can be formed by direct printing.

Also, the resistance heating body 4 and / or the insulating layer 5 was once smooth printed prior to drying-curing, by pressing the dimple-like jig, there is a method of transferring form a generally grid-like shape on the printing surface.

  By firing such a printed surface in the vicinity of the crystallization temperature of the glass, the substantially grid-like resistance heating element 4 and / or the insulating layer 5 can be obtained.

  The resistance heating element 4 and / or the insulating layer 5 do not have to be formed only on the surface of the resistance heating element 4, and there is no problem even if the resistance heating element 4 and / or the insulating layer 5 spread over the underlying plate-like ceramic body 2. It is not necessary to cover the entire surface of the resistance heating element 4. That is, the resistance heating element 4 and / or the insulating layer 5 may be formed only in a portion where stress is locally large and a crack is likely to occur, such as a portion where the coolant is sprayed.

  The resistance heating element 4 and / or the insulating layer 5 having such rough lattice-like uneven surfaces 40 and 50 are not entirely thick, and the stress due to the difference in thermal expansion is relieved in the concave portions 42 in the substantially lattice. As a result, the resistance heating element 4 and the insulating layer 5 are free from defects such as cracks.

  That is, according to the present invention, it is possible to suppress deterioration damage of the resistance heating element 4 and / or the insulating layer 5 while absorbing the difference in thermal expansion between the plate-shaped ceramic body 2 and the resistance heating element 4 and / or the insulating layer 5. An extremely reliable wafer heating apparatus can be obtained.

  Next, another configuration of the present invention will be described.

  Since the plate-like ceramic body 2 is formed of a ceramic having a large Young's modulus, deformation is small even when heat is applied, and the plate thickness can be reduced. Therefore, the heating time until heating to a predetermined processing temperature and a predetermined The cooling time from the processing temperature to the vicinity of room temperature can be shortened, the productivity can be improved, the Joule heat of the resistance heating element 5 can be quickly transmitted even with a thin plate thickness, and the temperature of the mounting surface 3 The variation can be made extremely small.

By the way, in order to satisfy such characteristics, the plate thickness of the plate-like ceramic body 2 is preferably 2 mm to 7 mm. If the plate thickness t is less than 2 mm, the plate thickness is too thin, so that the effect is small as a plate-like ceramic body 2 in which temperature variations are leveled, and variations in Joule heat in the resistance heating element 5 are placed as they are. since current is the temperature variation of the surface 3, mounting is because the temperature control of the surface 3 is difficult, the thickness t is obtain ultra the 7mm reversed, silicon carbide plate-shaped ceramic body 2 has a high thermal conductivity Edomo have a or a ceramic material such as aluminum nitride, as compared to the metal for the thermal conductivity is small, too large heat capacity of the ceramic plate 2, heating up it is heated to a predetermined process temperature This is because the cooling time from the time and the processing temperature to the cooling to around room temperature becomes long, and the productivity cannot be improved.

  Further, the depth of the bottomed metal case 11 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 the radiant heat between the plate-shaped ceramic body 2 and the bottomed metal case 11, and at the same time, there is a heat insulating effect from the outside. This is because the time until the temperature reaches a constant and uniform temperature is shortened.

  The wafer 90 is held in a state of being lifted from the mounting surface 3 by a wafer support pin 10 (not shown), and temperature variations due to contact with each other can be prevented.

Next, when the wafer heating apparatus 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 if it is used for attaching a resist film on the wafer 90, 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, the insulating layer 5 for maintaining insulation between the plate-like ceramic body 2 having semiconductivity and the resistance heating element 4 is made of glass or resin. it is possible to use, in the case of using a glass, the thickness thereof can not be maintained insulating withstand voltage is below 1.5kV in less than 100 [mu] m, the thickness conversely obtain ultra the 400 [mu] m, the ceramic plate 2 Since the difference in thermal expansion between the silicon carbide sintered body and the aluminum nitride sintered body to be formed becomes too large, cracks are generated and the insulating layer 5 does not function. Therefore, when glass is used as the insulating layer 5, the thickness of the insulating layer 5 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-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 5 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 for the main component aluminum nitride. It can be obtained by adding an elemental oxide and, if necessary, an alkaline earth metal oxide such as CaO and mixing them sufficiently to form a flat plate, followed by firing at 1900 to 2100 ° C. in nitrogen gas.

  In order to improve the adhesion of the resistance heating element 4 to the plate-like ceramic body 2, an insulating layer 5 made of glass may be formed. However, when sufficient glass is added to the resistance heating element 4 and sufficient adhesion strength is obtained by this, it can be omitted.

The glass forming the insulating layer 5 may be crystalline or amorphous, and has a heat-resistant temperature of 200 ° C. or higher and a coefficient of thermal expansion in the temperature range of 0 ° C. to 200 ° C. It is preferable to appropriately select and use one having a thermal expansion coefficient in the range of −5 × 10 ⁻⁷ / ° C. to + 5 × 10 ⁻⁷ / ° C. That is, if glass having a coefficient of thermal expansion outside 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 the insulating layer 5 made of glass on the plate-like ceramic body 2, the glass paste may be baked at a temperature of 600 ° C. or higher after the glass paste is applied by a screen printing method or the like. .

  When glass is used as the insulating layer 5, 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. in advance, and the insulating layer 5 is deposited. By subjecting the surface to be oxidized to an adhesion treatment, the adhesion to the insulating layer 5 made of glass can be enhanced.

  Hereinafter, examples and comparative examples of the present invention will be described (hereinafter, reference numerals indicating parts common to the examples and comparative examples may be indicated by either one).

  A plate made of aluminum nitride sintered body with a thermal conductivity of 100 W / (m · K), a specific gravity of 3.2, and a water absorption of 0%. A plurality of ceramic bodies 2 were produced.

  Next, in order to deposit the resistance heating element 4 on the plate-like ceramic body 2, a paste in which each powder of Pt, Au, Ag and glass is mixed is printed in a pattern shape of the resistance heating element 4 by a screen printing method. did. In order to improve the printability, the paste was made into a highly fluid body with a viscosity of about 100 poise, so that the uneven surfaces 40 and 50 after printing were naturally filled, regardless of the mesh size of the plate making, Finished with a very smooth printing surface.

Then, before the printing surface was completely dried, a dimple-like jig having various sizes was pressed to transfer a substantially lattice shape. Since the resistance heating element 4 immediately after printing has poor shape retention, a substantially lattice-like shape is not transferred, while the completely dried resistance heating element 4 has a high hardness and cannot be transferred.

  However, when the resistance heating element 4 was printed, it was possible to transfer a substantially lattice shape under the condition of drying at about 80 ° C. for about 10 minutes. Thereafter, the plate-like ceramic body 2 on which the resistance heating element 4 having the substantially lattice-shaped uneven surfaces 40 and 50 is formed is fired at 700 ° C., which is near the crystallization temperature of glass. A resistance heating element 4 could be obtained.

The resistance heating body 4 in order to sintering shrinkage at a rate of about several percent by baking, have good by using the dimple-shaped jig this shrinkage in advance expecting it size.

Here, the dimple-like jig, the method of transferring a substantially grid-like shape, Ru possible der to form a substantially grid-like shape by utilizing the mesh itself for making used during screen printing . Specifically, although the printability is slightly inferior, using a 40-600 mesh plate making based on JIS R6002, using a paste for a resistance heating element having a viscosity of about 3000 poise and a very high viscosity and shape retention. By printing, traces of plate making remain on the printed surface, and drying and baking as it is can form a grid-like groove with 0.2 to 80 irregularities per 1 mm width. The In other words, if you want to change the lattice-like grooves are not good if selected mesh size commensurate with the lattice shape to be formed. Thus, the plate making mesh used during screen printing, the method of making a substantially lattice-like shape, the dimple-shaped jig is not required, since the process is simplified, convenient. Of course, since the paste of the resistance heating element 4 is baked and shrunk at a rate of several percent depending on firing, it is needless to say that the shrinkage rate may be set to a mesh size that is expected in advance.

After that, the insulating layer 5 having the substantially lattice-shaped uneven surfaces 40 and 50 was formed on the resistance heating element 4. As a method of forming the insulating layer 5 having the substantially lattice-shaped uneven surfaces 40 and 50, a glass paste prepared by kneading ethyl cellulose as a binder and terpineol as an organic solvent into a glass powder by a screen printing method. First, it printed smoothly. Thereafter, like the resistance heating element 4, before the glass paste was completely dried, a dimple-like jig having various sizes was pressed to transfer a substantially lattice-like shape. Thereafter, the plate-like ceramic body 2 having the resistance heating element 4 formed with the substantially lattice-like insulating layer 5 is fired at 700 ° C., which is near the glass crystallization temperature, to obtain the substantially lattice-like insulating layer 5. .

In order to sintering shrinkage at a rate of about several percent by glass paste also firing, have good be used previously expected but the size of the dimple-like jig this shrinkage.

Here, the dimple-like jig, the method of transferring a substantially grid-like shape, Ru possible der to form a substantially grid-like shape by utilizing the mesh itself for making used during screen printing . Specifically, by using the plate making of 40 to 600 mesh based on JIS R6002, Ru can der the lattice-shaped grooves forming the uneven shape of 0.2 to 80 present / mm.

That is, it is needless to say that when changing the lattice-shaped groove, a mesh size corresponding to the lattice shape to be formed may be selected. Thus, the method of creating a substantially lattice-like shape using a plate-making mesh used at the time of screen printing is advantageous because a dimple-like jig is not required and the process is simplified. Of course, since glass paste is baked and shrunk at a rate of several percent depending on firing, it is needless to say that the shrinkage rate may be set to a mesh size with the expected size.

Before SL and the ceramic plate 2 in a case 11 attached, such as to produce a wafer heating apparatus 1.

  And 200V was applied to this, and after heating up to room temperature 300 degreeC, the refrigerant | coolant was discharged | emitted from the discharge port and the heating / cooling cycle test which cools from 300 degreeC to room temperature rapidly was repeated. Then, the number of heating / cooling cycles and the relationship between the resistance heating element 4 and peeling or cracking were examined.

  In the first heating / cooling cycle, the time from 300 ° C. to 50 ° C. was measured as the cooling time.

The results are shown in Table 1.

  Thus, the sample No. of the wafer heating apparatus 1 having uneven surfaces 40 and 50 such as a substantially lattice shape on the surface of the resistance heating element 4 and / or the insulating layer 5 is obtained. It was found that Nos. 2 to 31 were preferable because the resistance heating element 4 was not peeled off or cracked even when the heating / cooling cycle exceeded 4000 times.

  However, Sample No. which is a comparative example. As shown in FIG. 1, the wafer heating apparatus 1 having a flat surface of the resistance heating element 4 was cracked in the resistance heating element 4 in 2400 cycles, and was not practical.

  Further, the uneven surfaces 40 and 50 formed on the resistance heating element 4 and / or the insulating layer 5 of the plate-like ceramic body 2 have a substantially lattice shape, and the number of lattice-like grooves is 0.2 to 80 per 1 mm width. Sample No. which is an example of the wafer heating apparatus 1 is shown. 6 to 9 have resistance because they can suppress deterioration damage of the resistance heating element 4 and / or the insulating layer 5 while absorbing the difference in thermal expansion between the plate-shaped ceramic body 2 and the resistance heating element 4 and / or the insulating layer 5. It has been found that the number of times until the heating element 4 is cracked or peeled off is as large as 9,000, and the wafer heating apparatus 1 can be made highly reliable.

Still, before Symbol of the uneven surface 40, 50, the ratio of the concave portion of the thickness of the (tv) and the thickness of the convex portion (tp) (tp / tv) × 100 is 105 to 200%, and pre-Symbol resistance samples average thickness of the heating element 4 or a pre-Symbol insulating layer 5 is 3～60Myuemu No. 12-15, the heating and cooling cycles to crack or peeling occurs 1 0000 times, it was Tsu or partial greater preferred.

  And it turned out that it can be set as the wafer heating apparatus 1 with especially high reliability.

  In addition, Sample No., which is an example in which the surfaces of the resistance heating element 4 and the insulating layer 5 are uneven surfaces 40 and 50, are used. Sample Nos. 2 to 31 are comparative examples having no uneven surfaces 40 and 50. Compared to 1, the cooling time was as short as 300 seconds or less, and it was found that the uneven surface 40, 50, particularly the substantially lattice-shaped grooves, is preferable because the cooling time is small.

As the glass, ZnO—B ₂ O ₃ —SiO ₂ —MnO ₂ -based crystallized glass containing ZnO as a main component was good. Further, in an embodiment in which the insulating layer is preferably glass having 50 to 70% by mass of ZnO, 20 to 30% by mass of B ₂ O _3, 5 to 20% by mass of SiO ₂ , and 1 to 2% by mass of MnO _2. Some sample No. It was found that 17 to 19 had the most preferable heating and cooling cycle of 15,000 to 23200 times.

  The resistance heating element 4 is preferably made of at least two kinds of metals selected from Pt, Au, and Ag and glass, and this ratio is Pt: Au: glass = 30: 20: 50 mass by weight. %, Or Pt: Ag: Glass = 30: 20: 50 mass%.

  Each error should be within ± 5% by mass.

  By the way, the insulating layer 5 does not have to be formed only on the surface of the resistance heating element 4, and there is no problem even if it spreads over the underlying plate-like ceramic body 2.

It is sectional drawing of the wafer heating apparatus of this invention. (A) is a perspective sectional view of the plate-like ceramic body of the wafer heating apparatus of the present invention, and (b) is the sectional view. It is a perspective sectional view of the plate-like ceramic body of the wafer heating device of the present invention. It is a surface view of the plate-shaped ceramic body of the wafer heating apparatus of this invention. It is sectional drawing of the conventional wafer heating apparatus.

Explanation of symbols

1: Wafer heating device 2: Plate-like ceramic body 3: Placement surface 4: Resistance heating element 40: Concavity and convexity surface 41 of the resistance heating element: Convex part 42 of the resistance heating element 5: Concavity 5 of the resistance heating element 5: Insulating layer 50: Irregular surface 51 of the insulating layer: convex portion 52 of the insulating layer 52: concave portion of the insulating layer 6: power feeding portion 11: case 82: gas injection port 90: wafer Tv: thickness of the concave portion Tp: thickness of the convex portion

Claims (10)

The one main surface of the ceramic plate with a mounting surface mounting the wafer, a wafer heating apparatus having one or two circuits or more resistance heating elements on the other main surface, of the resistance heating element The surface is an uneven surface in which the ratio (tp / tv) × 100 of the thickness (tv) of the concave portion and the thickness (tp) of the convex portion is 105 to 200%, and the average thickness of the resistance heating element is 3 to 60 μm A wafer heating apparatus characterized by the above. Comprising an insulating layer covering some or all of the pre-Symbol resistance heating element, the surface of the insulating layer, the ratio of the concave portion of the thickness of the (tv) and the thickness of the convex portion (tp) (tp / tv) × 100 is 2. The wafer heating apparatus according to claim 1, wherein the wafer heating device is an uneven surface having an average thickness of 105 to 200% and an insulating layer thickness of 3 to 60 [mu] m . A wafer heating apparatus having one main surface of a plate-shaped ceramic body as a mounting surface on which a wafer is placed and having one or more resistance heating elements on the other main surface, the surface of the resistance heating body Is an uneven surface, and includes an insulating layer covering a part or all of the resistance heating element, and the surface of the insulating layer has a ratio (tp / thickness) of the thickness (tv) of the concave portion and the thickness (tp) of the convex portion. tv) A wafer heating apparatus, wherein x100 is 105 to 200%, and the insulating layer has an uneven surface with an average thickness of 3 to 60 μm. Before SL uneven surface is a wafer heating apparatus according to any one of claims 1-3, characterized in that a substantially lattice-shaped grooves. Wafer heating apparatus according to claim 4, before Symbol substantially lattice-shaped grooves, characterized in that in parallel with 0.2 to 80 lines per 1mm width.   The wafer heating apparatus according to claim 1, wherein the resistance heating element is made of at least two kinds of metals selected from Pt, Au, and Ag and glass.   The wafer heating apparatus according to claim 2, wherein the insulating layer contains glass as a main component. Wafer heating apparatus according to claim 1, characterized in that it comprises means for cooling by blowing gas before Symbol uneven surface. A feeding unit for supplying power independently to each of the resistance heating element, and a casing surrounding the power feeding unit, further comprising a gas injection port for cooling the pre-Symbol ceramic plate in the case The wafer heating apparatus according to claim 1, wherein: Method of manufacturing a wafer heating apparatus, and forming by screen printing an uneven surface of a wafer heating apparatus according to any one of the previous SL claims 1-9.

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