JP2008066295A - Heating element circuit pattern, susceptor mounted therewith and semiconductor manufacturing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heating element circuit pattern capable of uniforming temperature distribution of a susceptor, a hot plate, etc. not only in a steady state at a predetermined temperature but also in a transient state where the temperature drops or rises. To do.
A heating element circuit pattern is arranged such that a plurality of island-like heating elements 1 are distributed in an independent island shape on a substrate 2 or inside the substrate 2, and the heat generation density in the substrate 2 is substantially uniform. At the same time, all the island-shaped heating elements 1 are connected in parallel by the lead circuit 3. These island-shaped heating elements 1 have a characteristic that the resistance value increases as the temperature rises, and the lead circuit 3 needs to have a lower resistance value than the island-shaped heating element 1.
[Selection] Figure 1

Description

  The present invention relates to a heating element circuit pattern used for a heating element such as a heater when heat-treating an object to be processed such as a wafer, and more particularly to a heating element circuit pattern capable of making the temperature distribution of the object to be processed uniform. is there.

  2. Description of the Related Art Conventionally, particularly in a semiconductor manufacturing apparatus, a predetermined temperature is applied when a wafer or the like is heat-treated. At this time, it is necessary to perform processing without variation by making the temperature distribution of the wafer as uniform as possible. For example, in a film forming apparatus such as a CVD, the temperature distribution of the wafer, that is, the temperature distribution of the susceptor on which the wafer is placed affects the film thickness, and if the temperature is relatively high, the film thickness is relatively thick. If the temperature is relatively low, the film thickness becomes relatively thin. For this reason, it is required to make the temperature distribution of the susceptor uniform, and various heating element circuit patterns have been proposed.

  For example, Japanese Patent Laid-Open No. 2003-018224 proposes a heating element circuit pattern that can achieve a uniform temperature distribution even with a large wafer. In this heating element circuit pattern, an input electrode and an output electrode are provided at a substantially central portion of an insulating substrate, a substantially spiral heating element circuit is formed from a portion including the input electrode toward the outer periphery of the substrate, and further from the outermost periphery. A substantially spiral heating element circuit is formed toward the output electrode in the center.

  Further, even in a hot plate used for curing a resist in a process of forming a circuit pattern on a wafer, the temperature distribution affects the pattern resolution of the resist. Therefore, it is necessary to make the temperature distribution uniform. Moreover, in the case of the resist curing process, when the wafer is placed on the hot plate, the temperature of the hot plate once decreases, and then the temperature of the hot plate rises again, and a predetermined amount of heat is applied to the wafer. Remove from hot plate. At that time, it is desired to make the temperature distribution uniform even in a transient state in which the temperature of the wafer drops or rises.

However, in the heating element circuit pattern described in Japanese Patent Application Laid-Open No. 2003-018224, the temperature distribution in a steady state at a predetermined temperature is excellent, but as described above, the temperature drops or rises transiently. The temperature distribution in the state was not necessarily uniform.
Japanese Patent Laid-Open No. 2003-017224

  In view of the above-described conventional circumstances, the present invention makes the temperature distribution of the susceptor, hot plate, etc. uniform not only in a steady state at a predetermined temperature but also in a transient state where the temperature drops or rises. An object of the present invention is to provide a heating element circuit pattern that can be used.

  In order to achieve the above object, the heating element circuit pattern provided by the present invention is such that a plurality of island-like heating elements are distributed in an independent island shape on the substrate or inside the substrate, and the heat generation density in the substrate becomes substantially uniform. All the island-shaped heating elements are connected in parallel by a lead circuit so that the voltage applied to each island-shaped heating element becomes substantially constant, and these island-shaped heating elements become resistant as the temperature rises. The lead circuit has a characteristic of increasing the value, and the lead circuit has a lower resistance value than the island-shaped heating element.

  According to the present invention, not only in a steady state of a susceptor and a hot plate, but also in a transient state in which the temperature drops or rises, a heating element circuit pattern having a uniform temperature distribution, that is, excellent heat uniformity is provided. can do.

  In the heating element circuit pattern of the present invention, a plurality of independent heating elements are used as heating elements provided on or in the substrate, instead of a single continuous heating element. Then, as shown in FIG. 1, for example, a plurality of island-like heating elements 1 are arranged in an island-like manner on the substrate 2 so that the heat generation density in the substrate is substantially uniform, and all these island-like heating elements are arranged. 1 are connected in parallel by a lead circuit 3. The shape of the island-shaped heating element 1 is not particularly limited, and may be, for example, one formed by bending a metal foil (unit heating element 1a) as shown in FIG. For example, FIG. 1 shows an island-shaped heating element 1 having three unit heating elements 1a as one set.

  About the said island-shaped heat generating body, it is necessary to have the characteristic that resistance value rises with a rise in temperature. In addition, the resistance value of the lead circuit connecting each island-shaped heating element needs to be lower than the resistance value of the island-shaped heating element. This is because when the resistance value of the lead circuit is higher than the resistance value of the island-shaped heating element, the heating value of the lead circuit is higher than the heating value of the island-shaped heating element, making it difficult to obtain a uniform temperature distribution. . Moreover, the voltage applied to each island-shaped heating element can be made uniform by making the resistance value of the lead circuit lower than that of the island-shaped heating element.

  According to the heating element circuit pattern of the present invention, the temperature distribution on the substrate can be made uniform. That is, when a current is passed through the island-shaped heating elements connected in parallel, the island-shaped heating elements each start to rise in temperature. At this time, the voltage applied to each island-shaped heating element needs to be substantially constant. The temperature of each island-shaped heating element that rises in temperature often varies due to the influence of the position in the substrate. However, since the island-shaped heating element has a characteristic that the resistance value increases as the temperature rises, the island-like heating element having a relatively high temperature has a relatively high resistance value, and conversely, the island-like heating element has a relatively low temperature. The resistance value of the heating element is relatively low.

  At this time, since each island-shaped heating element is connected in parallel by a lead circuit, if the resistance value of the lead circuit is sufficiently lower than the resistance value of the island-like heating element, the voltage applied to each island-like heating element Are the same. Therefore, an island-like heating element having a relatively high temperature (high resistance value) has a smaller current flow than an island-like heating element having a relatively low temperature (low resistance value). Or the rate of temperature increase decreases. On the contrary, the island-like heating element having a relatively low temperature has a relatively low resistance value, but since the applied voltage is the same, the amount of flowing current increases and the temperature rises or the temperature rises. The speed of ascent increases.

  By such a mechanism, the temperature and resistance value of each island-shaped heating element are relatively small in variation, and the temperature distribution in the substrate can be made uniform. Moreover, even when the temperature rises or falls, the temperature changes by detecting the temperature difference between the island-like heating elements by their resistance values and adjusting the amount of current supplied to the heating element circuit pattern. Even in a transient state, the temperature of each island-shaped heating element can be made substantially uniform and a good temperature distribution can be achieved.

  In addition, as shown in FIG. 3, the island-like heating element 1 can be installed on the substrate 2 and the lead circuits 3 and 3 can be installed so as to sandwich the heating element 1. In this case, for example, the island-shaped heating elements are arranged in a dot shape so that the temperature distribution is uniform on the substrate. Although there is no restriction | limiting in particular regarding the shape of arrangement | positioning, if it arrange | positions at substantially equal intervals, since it becomes easy to become uniform, it is preferable. In particular, regarding the heating element used in this case, a voltage is applied in the thickness direction of the island-shaped heating element, and a current flows. Therefore, the volume resistance value of the island-shaped heating element is preferably higher than that of the above-described embodiment.

  In order to achieve the mechanism described above, it is preferable that each of the independent island-like heating elements is the same. Naturally, the resistance value and the temperature-resistance characteristics at room temperature (initially energized) Are preferably substantially the same. Moreover, it is preferable that the occupied area of each island-shaped heating element is also made substantially the same. That is, by making the area occupied by each island-shaped heating element substantially the same, the area of the substrate heated by each island-like heating element can be made the same, and the responsiveness to temperature can be made the same for each island-like heating element. The uniformity of temperature distribution on the substrate can be further improved.

  The resistance value of each island-shaped heating element is preferably within 5% of the average value in consideration of the recent increase in demand for heat uniformity. If there is more variation in resistance value than this, it is not preferable because the function of trying to make the temperature of each island-like heating element uniform does not work. If the resistance value varies within 5%, a temperature distribution of about ± 1% can be achieved. However, in order to achieve a soaking property of 0.5% or less and an excellent soaking property in a transient state, it is necessary to further suppress the resistance value of each island-like heating element to within 1%.

  Moreover, there is no restriction | limiting in particular regarding the width | variety and space | interval of the pattern which form an island-like heat generating body. However, in order to achieve uniform heat generation, the width and interval of the pattern is preferably 10 mm or less, and more preferably 1 mm or less. However, when the width of the pattern is 50 μm or less, for example, the variation in the width and interval of the metal foil that forms the heating element and the film formed by screen printing increases with respect to the pattern width, and the resistance value of each island-like heating element This is not preferable because the variation becomes large. The pattern interval is preferably 0.1 mm or more. This is because if the pattern interval is less than this, a short circuit between the circuits is likely to occur.

  With regard to the form in which the island-shaped heating element is sandwiched between the upper and lower lead circuits, the lead circuit can use, for example, a metal plate having substantially the same shape as the substrate. In this case, the lead circuit preferably has a low electrical resistance value, but the lead circuit on the wafer mounting surface side preferably has a high thermal conductivity. That is, the heat generated in the island-shaped heating element is transferred to the substrate through the lead circuit and heats the mounted object such as a wafer. Therefore, if the thermal conductivity of the lead circuit is low, it becomes a thermal resistance, and soaking is disturbed. Absent. Specifically, copper, aluminum and the like are preferable. In order to improve the heat resistance of the lead circuit, it is also possible to form a heat resistant coating such as a film of gold, silver, nickel, etc. on the surface by plating, vapor deposition, sputtering, thermal spraying, or the like.

  The resistance value of each island-shaped heating element may be designed in consideration of the number of island-shaped heating elements to be formed and the resistance value of the entire circuit, and is not particularly limited. For example, if a large number of island-shaped heating elements are arranged, the overall resistance value can be adjusted by increasing the resistance value of each island-shaped heating element accordingly. For example, if the overall resistance value is 10Ω, and the resistance value of the lead circuit is sufficiently small, if 10 island heating elements are formed, the resistance value of each island heating element is reduced to 100Ω. In addition, if 20 island-shaped heating elements are formed, the resistance value of each island-shaped heating element can be set to 20Ω as a whole.

  Moreover, there is no restriction | limiting in particular regarding the number of island-shaped heat generating bodies, and if it is two or more, the function of this invention can be expressed. However, in practice, since the temperature distribution can be reduced by forming a large number of island-shaped heating elements, it is needless to say that a larger number of island-shaped heating elements per unit area is preferable. For example, if the area of the substrate is about 320 mm on which a 300 mm wafer can be placed, it is preferable to form at least five, preferably 10 or more island-shaped heating elements. Furthermore, if the area is about this, it is possible to form about 100 island-shaped heating elements.

  Further, when the island-like heating elements are arranged on the circular substrate, it is preferable that the island-like heating elements 1 are arranged concentrically as shown in FIG. In FIG. 1, three island-shaped heating elements are arranged at the center, eight island-shaped heating elements are arranged on the outer side, and twelve island-like heating elements are arranged on the outer side in a concentric manner. The temperature distribution on the substrate 2 can be made uniform. Of course, in addition to such an arrangement, it goes without saying that various arrangements can be changed according to the temperature distribution and the environment.

  In addition, the same arrangement method as described above can be applied to the method of sandwiching the island-shaped heating element as shown in FIG. For example, in FIG. 4, 13 island-shaped heating elements 1 are arranged concentrically. In FIG. 5, the island-shaped heating elements 1 are arranged at equal intervals. By arranging in this way, a uniform temperature distribution can be achieved.

  Moreover, as a formation method of the island-shaped heat generating body in this method, it can be set as an island-shaped heat generating body by press-molding the powder used as a raw material to a predetermined shape, for example, and baking it. At this time, by making the shape and weight of the pressed body the same, it is possible to obtain an island-shaped heating element having a relatively uniform resistance value. At this time, an electrode can be formed on the surface in contact with the lead circuit. Moreover, a solvent can be added to the powder used as the raw material of the island-shaped heating element to form a paste, which can be applied onto a lead circuit (substrate) by a method such as screen printing and baked. In this case, by making the pattern shape and the film thickness of each island-shaped heating element uniform, an island-shaped heating element having a uniform resistance value can be obtained.

  The island-shaped heating element and the lead circuit described above can be formed from, for example, a metal foil. There is no restriction | limiting in particular about the kind of metal foil, What is necessary is just to have the characteristic that it has a substantially uniform thickness and a resistance value rises with a raise in temperature. Moreover, since it uses as a heater, it is preferable that an island-like heat generating body and a lead circuit have oxidation resistance. Preferred metal foils include stainless steel foil and nichrome foil. An island-like heating element and a lead circuit are formed by etching from these metal foils and mounted on a substrate, whereby a susceptor or a hot plate having a heating element circuit pattern can be manufactured.

  Although there is no restriction | limiting in particular regarding the thickness of the metal foil to be used, It is preferable that it is 0.01 mm or more. A thickness less than this is not preferable because it often breaks during handling and the yield decreases. A particularly preferable thickness is 0.02 mm or more, and when this thickness is reached, it is not damaged by handling. Moreover, although there is no restriction | limiting also about the upper limit of the thickness of metal foil, in order to make resistance value uniform and to suppress the dispersion | variation by an etching to the minimum, it is preferable that it is 1 mm or less. When the thickness exceeds 1 mm, the etching time becomes longer, and variations in the line width of the island-shaped heating element and the lead circuit often occur. A particularly preferable upper limit of the thickness is 0.3 mm.

  In addition, when an island-like heating element is formed on the surface of the substrate, it is particularly preferable to use a metal foil. By using the metal foil, in particular, in the thickness range of 0.01 to 1 mm, the variation in thickness and line width after etching is relatively small, so that a stable heating element circuit pattern can be provided. This is because the temperature distribution can be made uniform.

  Further, in the structure in which the island-shaped heating element is sandwiched from above and below by the lead circuit as shown in FIG. 3, it is necessary to increase the resistance value in the thickness direction of the island-shaped heating element to some extent. For this reason, as a material of a heat generating body, what doped strontium and lead to barium titanate or barium titanate can be used. Since these materials have a relatively high resistance value and a resistance value change with respect to temperature is very large, it is possible to achieve soaking by controlling the composition of the island heating elements according to the temperature used. For example, in barium titanate, the volume resistivity changes by three orders of magnitude between 120 ° C and 170 ° C. For this reason, the resistance value becomes very large in the portion where the temperature is high, the current flowing through the island-shaped heating element is relatively small, the heat generation amount is lowered, and the temperature is also lowered. On the other hand, since the resistance value is low in the low temperature portion, the amount of flowing current increases and the amount of heat generation also increases, so the temperature also rises. Further, when strontium is doped into this barium titanate, the temperature at which the resistance value changes rapidly according to the amount of doping decreases. On the other hand, when lead is doped, the temperature at which the resistance value changes abruptly increases. Therefore, the doping amount may be adjusted according to the temperature to be used.

  In addition, the island-shaped heating element in the form of FIG. 3 has a much higher volume resistivity than the metal foil in the case of barium titanate as described above, for example. It is preferable to form an electrode such as silver, gold, or nickel to reduce the contact resistance with the lead circuit. In addition, a lead circuit is formed on a ceramic substrate such as aluminum nitride by metallizing with tungsten or the like, and then a paste is formed by adding a solvent or the like to a powder of barium titanate or the like which is a raw material of the island-like heating element. It is also possible to form an island-shaped heating element by printing on and firing.

  As a method of using a heating element circuit pattern using an island-shaped heating element made of metal foil, for example, there is a method in which a metal foil etched into a predetermined shape is sandwiched between two substrate members while ensuring insulation. . For example, a stainless steel plate on which an island-shaped heating element formed from a metal foil is mounted on an insulating substrate such as aluminum nitride and a resin having heat resistance such as polyimide resin, silicon resin, epoxy resin, phenol resin, etc. is applied, Alternatively, using a stainless steel plate with these resin sheets affixed to the surface, it is stacked on the aluminum nitride substrate so as to sandwich the gold island-like heating element, and the aluminum nitride substrate and the stainless steel plate are fixed using a method such as screwing. do it.

  Further, in order to make the adhesion between the island-shaped heating element and the aluminum nitride substrate uniform, the above resin may be inserted between the metal foil island-shaped heating element and the aluminum nitride substrate. In addition, since the above-mentioned resin has comparatively low thermal conductivity, the temperature responsiveness may be slow. Therefore, you may add the filler for improving thermal conductivity in resin. The filler in this case is not particularly limited as long as it has insulating properties and heat resistance and has higher thermal conductivity than the above resin, and for example, silica, alumina, aluminum nitride, boron nitride, or the like can be used.

  The island-shaped heating element and lead circuit of the present invention can be formed not only by the metal foil described above but also by screen printing. For example, a paste mainly composed of tungsten (W) or molybdenum (Mo) is applied to an insulating ceramic green sheet, another green sheet is laminated, and then degreased and fired. A heating element circuit pattern can be embedded.

  Moreover, as a board | substrate in this invention, in order to improve the uniformity of temperature distribution, the thing whose heat conductivity is 100 W / mK or more is preferable. For example, in addition to conductive substrates such as metals or metal-ceramic composites, insulating ceramic substrates such as aluminum nitride can be used. In the case of a conductive substrate such as a metal or a composite of metal and ceramics, it is necessary to interpose a resin or the like for insulation between the island-like heating element and the substrate as described above. The use temperature depends on the heat-resistant temperature of the resin.

  The heating element circuit pattern of the present invention described above is suitable for heaters such as susceptors and hot plates. That is, a susceptor or a hot plate for a semiconductor manufacturing apparatus can obtain a uniform temperature distribution by mounting the substrate on which the heating element circuit pattern of the present invention is mounted. In particular, since a uniform temperature distribution can be obtained even in a transient state in which the temperature of the wafer drops or rises, it is particularly excellent as a coater developer.

  Furthermore, it is possible to mount a cooling module on the susceptor or hot plate on which the heat generating circuit pattern of the present invention is formed. The cooling module is formed using a metal plate such as aluminum or copper on the opposite side of the wafer mounting surface of the susceptor, for example. The cooling module may be movable or may be attached to the susceptor by a mechanical method such as screwing. In particular, if the cooling module is made movable and is brought into contact with or separated from the susceptor, the susceptor can be quickly cooled, so that the throughput can be improved.

  Further, more efficient cooling can be achieved by providing a flow path in the cooling module and flowing a refrigerant. For example, a stainless steel pipe is attached to a metal plate such as aluminum or copper, or a countersink process is applied to the metal plate, and then another metal plate is joined to form a cooling module having a flow path. it can. The refrigerant flowing through the flow path is not particularly limited as long as it does not corrode the cooling module, and a gas such as air or inert gas, or a liquid such as water, galden, or an organic solvent such as alcohol can be used. .

[Example 1]
As substrates, three types of aluminum nitride (AlN) substrates having thermal conductivity of 100 W / mK, 150 W / mK, and 200 W / mK were processed into a diameter of 330 mm and a thickness of 5 mm, and two each were prepared. Using these three types of AlN substrates, the heating element circuit pattern shown in FIG. 1 is formed on one of the substrates, and the other substrate is overlapped and sandwiched, and then the two substrates are fixed by screwing. A susceptor for heating the wafer was prepared.

  The island-like heating element in the heating element circuit pattern is formed by bending a stainless steel foil having a thickness of 50 μm as shown in FIG. 2 to form a unit heating element 1a, and three unit heating elements 1a in one set are shown in FIG. It was set as the island-shaped heat generating body 1 shown. The pattern width of the island-shaped heating element 1 was 0.2 mm, and the pattern interval was 0.3 mm. In addition, each island-shaped heating element 1 has a substantially identical shape, and 23 are arranged on three concentric circles so that the heat generation density in the substrate 2 is substantially uniform.

  These island-shaped heating elements 1 are connected in parallel by a lead circuit 3 having a width of several millimeters arranged substantially concentrically. In addition, a through hole was provided in a portion corresponding to the electrode position on the opposite side of the wafer mounting surface of the substrate 2, the electrode 4 (black circle portion in FIG. 1) was taken out, and connected to an external power source. The resistance value of each island-shaped heating element 1 was 40Ω, and the variation of the resistance value was within 0.5%.

As a comparative example, in the same manner as the heating element circuit pattern described in Japanese Patent Application Laid-Open No. 2003-018224, an input electrode and an output electrode are provided at a substantially central portion of the AlN substrate, and a stainless steel foil is provided from the portion including the input electrode toward the outer periphery of the substrate. A substantially spiral heating element circuit was formed, and a substantially spiral heating element circuit was formed of stainless steel foil from the outermost periphery toward the output electrode at the center. The same AlN substrate and stainless steel foil as those described above were used. Further, an alumina (Al ₂ O ₃ ) substrate having a thermal conductivity of 30 W / mK is processed into the same shape as above, and the heating element circuit pattern of FIG. 1 is sandwiched between them and screwed to produce a susceptor as described above. did.

  About the obtained susceptor of each sample, proximity was arrange | positioned on the mounting surface and it formed so that the distance between a wafer and a mounting surface might become uniform with 0.1 mm. The susceptor of each sample was heated to 130 ° C., and the temperature distribution was measured with a wafer thermometer. Next, with each susceptor kept at 130 ° C., a wafer at room temperature was placed on the susceptor, and the temperature distribution of the wafer 30 seconds and 60 seconds after the placement was measured with a wafer thermometer. The obtained results are shown in Table 1 below. From this result, it can be seen that the heating element circuit pattern of the present invention exhibits excellent temperature uniformity not only in a steady state (130 ° C.) but also in a transient state (30 seconds and 60 seconds after placement).

[Example 2]
The heating element circuit pattern of FIG. 1 was formed by screen-printing W paste on the same three types of AlN substrates as in Example 1, and susceptors were respectively produced. However, the thickness of the substrate at this time was 10 mm, and a heating element circuit pattern was formed on the opposite side of the wafer placement surface. Each island-shaped heating element had a resistance value of 50Ω and a variation in resistance value was within ± 1%.

  About the obtained susceptor of each sample, the test similar to the said Example 1 was performed, the thermal uniformity in a steady state (130 degreeC) and a transient state (30 seconds and 60 seconds after mounting) was evaluated, and the result was obtained. The results are shown in Table 2 below. Also from this result, it can be seen that the heating element circuit pattern of the present invention exhibits excellent thermal uniformity not only in a steady state but also in a transient state.

[Example 3]
As a substrate, a Si—SiC composite having a thermal conductivity of 150 W / mK, an Al—SiC composite having a thermal conductivity of 180 W / mK, and copper having a thermal conductivity of 400 W / mK are used in the above Example 1. 1 were prepared, and the heating element circuit pattern of FIG. 1 was formed in the same manner as in Example 1 to prepare susceptors. However, since these substrate materials are conductive, insulation with the substrate is secured by sandwiching the island-shaped heating element and the lead circuit with a polyimide resin having a thickness of 100 μm.

  About the obtained susceptor of each sample, the test similar to the said Example 1 was performed, the thermal uniformity in a steady state (130 degreeC) and a transient state (30 seconds and 60 seconds after mounting) was evaluated, and the result was obtained. The results are shown in Table 3 below. Also from this result, it can be seen that the heating element circuit pattern of the present invention exhibits excellent thermal uniformity not only in a steady state but also in a transient state.

[Example 4]
Barium titanate powder was press-molded and fired in a nitrogen atmosphere at 1400 ° C. to form an island-shaped heating element having a diameter of 10 mm and a thickness of 2 mm. Silver paste was applied to the upper and lower surfaces of this island-shaped heating element, placed on a copper plate having a diameter of 330 mm and a thickness of 3 mm, and baked in a nitrogen atmosphere at 850 ° C. Then, the copper plate of the same shape was installed so that an island-shaped heat generating body might be inserted | pinched, and it mutually fixed with the screw. The island-shaped heating elements were arranged on the copper plate at equal intervals with a pitch of 50 mm. Next, an AlN substrate having a diameter of 330 mm, a thickness of 5 mm, and a thermal conductivity of 150 W / mK is prepared for mounting the wafer, a screw hole is formed in the AlN substrate on the opposite side of the wafer mounting surface, and the copper plate corresponding to the position In addition, large through-holes were formed so as not to break each other due to thermal expansion, and were fixed with screws. This was tested for heat uniformity in the same manner as in Example 1 above. The results are shown as sample 12 in Table 4 below.

  Further, as in Example 1, two AlN substrates having a diameter of 330 mm, a thickness of 5 mm, and a thermal conductivity of 150 W / mK were prepared. On one side of these substrates, 1% of yttria, an organic solvent, and a binder were added to W powder to prepare a paste. This was printed on almost the entire surface by screen printing and baked in a nitrogen atmosphere at 1800 ° C. to form a lead circuit. Next, an organic solvent and a binder are added to barium titanate on one of the substrates on which the lead circuit is formed to form a paste, a pattern with a diameter of 30 mm is formed at a pitch of 60 mm, and fired in a nitrogen atmosphere at 1500 ° C. A heating element was formed. Then, another substrate on which only the lead circuit was formed was screwed in the same manner as described above to obtain a wafer holder. This was evaluated in the same manner as in Example 1 above. The results are shown as sample 13 in Table 4 below.

[Example 5]
Each of the above susceptors of Samples 1 to 13 was actually used for the resist curing process. As a result, good patterns could be formed except for Samples 4 to 5, which are comparative examples. Among them, the susceptors of Samples 2 to 3 and Samples 7 to 13 were particularly excellent in pattern accuracy.

It is a schematic plan view showing one specific example of the heating element circuit pattern according to the present invention. It is a schematic plan view which shows one specific example of the island-shaped heat generating body in this invention. It is a schematic sectional drawing which shows the other specific example of the island-shaped heat generating body in this invention. It is a schematic top view which shows the example of arrangement | positioning of the island-shaped heat generating body in this invention. It is a schematic plan view which shows the other example of arrangement | positioning of the island-shaped heat generating body in this invention.

Explanation of symbols

1 Island Heating Element 1a Unit Heating Element 2 Substrate 3 Lead Circuit 4 Electrode

Claims (14)

  A plurality of island-shaped heating elements are distributed in an independent island shape on the substrate or inside the substrate, and are arranged so that the heat generation density in the substrate is substantially uniform. The island heating elements are connected in parallel so that the voltage applied to the island heating elements is substantially constant. These island heating elements have a characteristic that the resistance value increases as the temperature rises, and the lead circuit is more than the island heating elements. A heating element circuit pattern characterized by a low resistance value.   2. The heating element circuit pattern according to claim 1, wherein the lead circuit sandwiches the island-shaped heating element vertically. 3.   The heating element circuit pattern according to claim 1 or 2, wherein the occupying areas of the island heating elements are substantially the same.   The heating element circuit pattern according to claim 1, wherein the resistance values of the island-shaped heating elements are substantially the same.   The heating element circuit pattern according to claim 1, wherein the island-shaped heating element and the lead circuit are made of metal foil.   The heating element circuit pattern according to claim 5, wherein the metal foil is made of nichrome or stainless steel.   The heating element circuit pattern according to claim 1, wherein the island-shaped heating element and the lead circuit are made of tungsten or molybdenum.   The heating element circuit pattern according to claim 2, wherein the island-shaped heating element is a ceramic heating element.   The heating element circuit pattern according to any one of claims 1 to 8, wherein the substrate has a thermal conductivity of 100 W / mK or more.   The heating element circuit pattern according to claim 9, wherein the substrate is aluminum nitride.   The heating element circuit pattern according to claim 9, wherein the substrate is a metal-ceramic composite.   A susceptor for a semiconductor manufacturing apparatus, comprising a substrate on which the heating element circuit pattern according to claim 1 is formed.   A semiconductor manufacturing apparatus comprising the susceptor according to claim 12.   The semiconductor manufacturing apparatus according to claim 12, wherein the semiconductor manufacturing apparatus is a coater developer.

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