JP4325083B2 - Ceramic heater unit for semiconductor manufacturing apparatus and semiconductor manufacturing apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ceramic heater unit for a semiconductor manufacturing apparatus and a semiconductor manufacturing apparatus using the ceramic heater unit. In particular, in a semiconductor manufacturing apparatus such as a CVD (Chemical Vapor Deposition) apparatus, a plasma CVD apparatus, an etching apparatus, etc. The present invention relates to a ceramic heater unit for a semiconductor manufacturing apparatus for heating and reacting uniformly and a semiconductor manufacturing apparatus using the ceramic heater unit.
[0002]
[Prior art]
When a film is formed on the surface of a semiconductor wafer, a large number of semiconductor wafers are held in a rack and placed in a container such as quartz glass, and heated from the outer periphery of the container to a predetermined temperature with a heater (hot wall Formula), a method of supplying a gas for etching or film formation into a container and reacting it has been used.
[0003]
FIG. 4 is a diagram conceptually showing a form of a conventional semiconductor manufacturing apparatus adopting the above-described method. As shown in FIG. 4, a plurality of semiconductor wafers 2 to be processed are held by a rack 53 in a chamber 100 for a CVD apparatus, a plasma CVD apparatus, or a high temperature etching apparatus. A film forming reaction gas and an etching gas are introduced from the gas inlet 200 and supplied onto the semiconductor wafer 2 through the gas shower unit 4. A heater 51 is disposed so as to surround the chamber 100. Inside the chamber 100, a predetermined film is formed on the surface of the semiconductor wafer 2 by the supplied gas, or etching is performed on the surface of the semiconductor wafer 2. Note that a temperature measuring tube 400 is provided inside the chamber 100, a thermocouple 401 is arranged therein, and an exhaust port 300 is provided for exhausting the inside of the chamber 100.
[0004]
In the apparatus shown in FIG. 4, since the semiconductor wafer 2 and the heater 51 are separated from each other, the heating rate of the wafer cannot be increased, and the entire semiconductor wafer 2 is made uniform after heating is started by the heater 51. It took time to get heated. Although the temperature inside the chamber 100 is measured by the thermocouple 401 inserted inside the chamber 100, it is difficult to rapidly raise the temperature inside the chamber 100 because it is heated by the heater 51 from the outside of the chamber 100. Met. For this reason, the processing speed of the semiconductor wafer per batch was limited, and the manufacturing cost was increased.
[0005]
Therefore, by setting as many semiconductor wafers as possible in one batch and processing in large quantities, the processing cost per semiconductor wafer has been reduced. For example, if a large number of semiconductor wafers, such as 100 wafers per batch, are processed at the same time, the time required for temperature increase, temperature equalization, and temperature decrease required for each semiconductor wafer becomes less problematic. In a semiconductor device for a memory IC such as a DRAM (Dynamic Random Access Memory) capable of mass production of a small number of products, by increasing the throughput of semiconductor wafers per batch in this manner, The manufacturing cost of the semiconductor device has been reduced.
[0006]
[Problems to be solved by the invention]
However, for example, in a logic IC semiconductor device that requires a wide range of required performance and requires a small amount of various types of custom production, the processing amount of semiconductor wafers per batch is limited. The method cannot be adopted. Therefore, it is required to shorten the cycle of temperature increase, reaction, and temperature decrease per batch to reduce the manufacturing cost per batch. Since the reaction time is related to performance such as the film thickness of the semiconductor device product, it cannot be shortened, and it is required to shorten the temperature raising and lowering time.
[0007]
In the system using the conventional apparatus shown in FIG. 4, it takes time to raise the temperature because of indirect heating by an external heater. For example, it took 20 minutes or more to hold 100 semiconductor wafers in a rack and heat from room temperature to 600 ° C. It is required that the temperature raising time be ½ or less, preferably 1/10 or less. Therefore, it is required that the time for raising the temperature from room temperature to 600 ° C. is within 10 minutes, preferably within 2 minutes.
[0008]
Furthermore, it is also required to uniformly heat the semiconductor wafer so that variations in the performance of IC products do not occur due to variations in the thickness of the laminated film and etching depth in the wafer. Therefore, there is a need for a semiconductor manufacturing apparatus that can quickly heat a semiconductor wafer to a predetermined temperature, soak the temperature, start reaction quickly, and cool it quickly after reaction to take out the semiconductor wafer from the chamber. It has been.
[0009]
Accordingly, an object of the present invention is for a semiconductor manufacturing apparatus capable of rapidly raising the temperature of a semiconductor wafer to a predetermined temperature, allowing the reaction to be uniformly heated, and allowing the temperature to be lowered rapidly even after completion of the reaction. A ceramic heater unit and a semiconductor manufacturing apparatus using the ceramic heater unit are provided. Hereinafter, in the present invention, a collective heater in which a plurality of single heaters are arranged is referred to as a heater unit.
[0010]
[Means for Solving the Problems]
In the conventional indirect heating method in which a semiconductor wafer is held in a rack and heated by the heater from the outside of the chamber with the heater, even if the output of the heater is increased, there is a limit to the improvement of the heating rate. In addition, the temperature uniformity after the temperature rise is not sufficient, and as a result, the uniform and rapid film forming or etching function on the wafer surface is impaired, and the required performance of the semiconductor device as a heater product may be satisfied. I examined the cause of the failure. Based on the results of the study, the inventors came up with the idea of setting and heating one semiconductor wafer between each heater of a ceramic heater unit in which a plurality of thin heaters are arranged in the vertical direction as shown in FIG. . That is, the ceramic heater unit for a semiconductor manufacturing apparatus according to the present invention includes a ceramic sintered body base and a semiconductor manufacture having a thickness of 5 mm or less, including a ceramic sintered body base and a conductive layer that forms a heater circuit pattern on the ceramic sintered base. A plurality of ceramic heaters for the device are arranged at a predetermined interval, The conductive layer is formed on the surface of the ceramic sintered body substrate, and further includes a protective layer formed so as to cover the surface of the conductive layer, and the protective layer includes 50 masses of either aluminum nitride or silicon nitride. % Or more, A semiconductor wafer to be processed is disposed between the plurality of ceramic heaters. Preferably, the thickness of the ceramic heater is 2 mm or less. Preferably, the ceramic includes one selected from the group consisting of aluminum nitride, silicon nitride, aluminum oxide, aluminum oxynitride, and silicon carbide.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
By adopting the heater configuration as described above, the distance between the semiconductor wafer and the heater is reduced, so that the semiconductor wafer can be rapidly heated. More specifically, the semiconductor wafer set on the heater is directly heated by heat conduction, and the semiconductor wafer is heated by radiation and heat conduction through the reaction gas from the heater arranged above the wafer. The inventors of the present application have obtained the knowledge that the semiconductor wafer can be efficiently heated and the semiconductor wafer can be rapidly heated.
[0012]
However, even if the heating method based on the above knowledge is adopted, if the thickness of the heater is increased, it takes time to raise or lower the temperature due to the heat capacity of the heater itself. If the heater is thicker than 5 mm, it takes 10 minutes or more to raise the temperature of the semiconductor wafer from room temperature to 600 ° C. Therefore, the request cannot be satisfied. Therefore, the inventors of the present application can increase and decrease the temperature by using a heater as thin as possible, specifically by using a heater having a thickness of 5 mm or less, preferably by using a heater having a thickness of 2 mm or less. It has been found that the time required can be greatly reduced.
[0013]
By the way, in a heater of a conventional single wafer type semiconductor manufacturing apparatus, a coil in which a molybdenum wire having a diameter of 0.5 to 1.0 mm is wound with a winding diameter of about 4 mm is disposed in the groove of the aluminum nitride molded body. After covering the above coil with a single aluminum nitride molded body, the coil was embedded in the aluminum nitride sintered body by a hot press method. In the heater manufactured as described above, the thickness of the heater depends on the coil winding diameter. Since the minimum winding diameter of the coil is about 4 mm, it is difficult to produce a thin heater having a thickness of 5 mm or less. Further, when the aluminum nitride molded body is handled, if the strength of the molded body is low, cracks and chips are likely to occur in the molded body. For this reason, it is difficult to manufacture a thin heater using the above-described coil, and considering the handling at the time of manufacturing, considering the maintenance of the quality at the time of mass production of heaters and heaters having a thickness of about 10 mm, even the thinnest ones Only a heater having a thickness of about 15 to 30 mm can be produced.
[0014]
As a result of various investigations, the inventors of the present application formed a conductive layer as a heater heating circuit on the surface of the ceramic thin sintered body by printing or the like, and baked. It has been found that a thin heater can be produced by bonding with an adhesive layer interposed. Alternatively, a thin heater can be manufactured by baking a conductive layer on the surface of a thin sintered body in the same manner as described above, and then forming a protective layer for protecting the conductive layer from a corrosive reaction gas such as halogen. The present inventors have found that this can be done.
[0015]
Accordingly, the ceramic heater for a semiconductor manufacturing apparatus according to the present invention is a ceramic heater having a thickness of 5 mm or less, and a ceramic sintered body base material and a conductive layer for forming a heater circuit pattern on the ceramic sintered body base material With. Preferably, the thickness of the ceramic heater is 2 mm or less.
[0016]
The ceramics preferably contains, as a main component, one selected from the group consisting of aluminum nitride, silicon nitride, aluminum oxide, aluminum oxynitride, and silicon carbide from the viewpoint of heat resistance and corrosion resistance. It is particularly desirable that the ceramic contains aluminum nitride as a main component from the viewpoint that it has high thermal conductivity due to the thermal uniformity of the ceramic heater and high corrosion resistance against halogen gases such as fluorine and chlorine.
[0017]
The conductive layer preferably contains at least one metal selected from the group consisting of tungsten, molybdenum, silver, palladium, platinum, nickel and chromium from the viewpoint of heat generation characteristics at a high temperature.
[0018]
In the ceramic heater for a semiconductor manufacturing apparatus according to one aspect of the present invention, the ceramic sintered body base includes a first ceramic sintered body and a second ceramic sintered body. The ceramic heater further includes an adhesive layer. The conductive layer is formed on the surface of the first ceramic sintered body. The adhesive layer is interposed between the surface of the first ceramic sintered body on which the conductive layer is formed and the second ceramic sintered body, and the first ceramic sintered body, the second ceramic sintered body, Join.
[0019]
Moreover, a ceramic heater for a semiconductor manufacturing apparatus according to another aspect of the present invention includes a protective layer formed so that a conductive layer is formed on a surface of a ceramic sintered body substrate and covers the surface of the conductive layer. Further prepare.
[0020]
From the viewpoint of heat resistance, the adhesive layer or the protective layer is made of, for example, B-Si-O-based, Al-Si-O-based, Y-Al-O-based, Yb-Nd-Ca-O-based glass, or the like. It is desirable to include non-oxide ceramics. From the viewpoint of heat resistance and corrosion resistance, the adhesive layer or protective layer preferably contains non-oxide ceramics. When the adhesive layer or the protective layer includes a non-oxide ceramic, it is preferable to include 50% by mass or more of aluminum nitride or silicon nitride from the viewpoint of heat resistance and corrosion resistance.
[0021]
From the viewpoint of suppressing damage to the ceramic heater due to thermal stress during rapid heating and rapid cooling, the thermal expansion coefficient of the adhesive layer or protective layer constituting the heater of the present invention is comparable to that of the ceramic sintered body substrate described above. Desirably 3 × 10 ^-6 / ℃ or more 8 × 10 ^-6 It is desirable to be within the range of / ° C. or less. For example, as durability, it is preferable that the ceramic heater can be used without cracking even if a heat cycle of 1000 cycles or more is applied in a heat cycle in which the temperature is raised from room temperature to the reaction temperature and cooled to room temperature.
[0022]
A semiconductor manufacturing apparatus according to the present invention is configured such that a plurality of ceramic heaters configured as described above are arranged at predetermined intervals, and a semiconductor wafer to be processed is arranged between the plurality of ceramic heaters. It is what is done. Preferably, the semiconductor manufacturing apparatus is configured to dispose a plurality of ceramic heaters so that the lower part of the semiconductor wafer is heated by heat conduction and the upper part of the semiconductor wafer is heated by radiation and heat conduction. With this configuration, the length of the chamber can be shortened by limiting the number of batch processes in accordance with custom production, so that the semiconductor manufacturing apparatus can be made compact. Moreover, since the volume of the chamber can be reduced, the heat capacity of the chamber is reduced, and the temperature drop rate of the semiconductor wafer can be improved.
[0023]
By using the semiconductor manufacturing apparatus of this invention, after setting a semiconductor wafer between individual ceramic heaters, the temperature is rapidly raised from room temperature to a predetermined reaction temperature, and after completion of the reaction, the semiconductor wafer is rapidly cooled. Can be taken out. As a result, for example, the manufacture of a semiconductor device for a memory IC capable of reducing the manufacturing cost by mass production by improving the throughput even in the manufacture of a semiconductor device for a logic IC that requires custom production of a small variety of products. It becomes possible to manufacture a semiconductor device for a logic IC at a cost similar to the above.
[0024]
The semiconductor manufacturing apparatus of the present invention can be applied to a CVD process, a plasma CVD process, or a high temperature etching process.
[0025]
FIG. 1 is a diagram conceptually showing one embodiment of a semiconductor manufacturing apparatus for reacting the surface of a semiconductor wafer using a heater unit according to the present invention.
[0026]
As shown in FIG. 1, a large number of semiconductor wafers 2 to be processed are arranged in a chamber 100 for a plasma CVD apparatus, a CVD apparatus or a high temperature etching apparatus. The semiconductor wafer 2 is held on each ceramic heater 1. A number of ceramic heaters 1 are attached to a heater support 3 to constitute a heater unit. The ceramic heater 1 is configured by forming a heater circuit pattern 11 as a conductive layer on a ceramic sintered body base material. A film forming reaction gas and an etching gas are introduced from the gas inlet 200 and supplied onto the respective semiconductor wafers 2 through the gas shower unit 4. By energizing the heater circuit pattern 11 of the ceramic heater 1, each semiconductor wafer 2 is heated by direct heat conduction from each ceramic heater 1 positioned in contact with the semiconductor wafer 2. The ceramic heaters 1 are also positioned on the respective semiconductor wafers 2 at a distance of about 10 mm. Each semiconductor wafer 2 is also heated by the radiation of the far-infrared effect of the ceramic heater 1 and the heat conduction through the reaction gas. Since the semiconductor wafer 2 can be simultaneously heated from above and below as described above, the semiconductor wafer 2 can be rapidly heated.
[0027]
As shown in FIG. 1, even if a heater unit including ceramic heaters 1 is configured, if the thickness of each ceramic heater 1 is large, the semiconductor wafer 2 is rapidly heated by the heat capacity of the ceramic heater 1 itself. In addition, it takes time to cool the semiconductor wafer 2 even in the cooling process after the completion of the reaction. Therefore, when the thickness of the ceramic heater 1 is large, even if the semiconductor manufacturing apparatus having the structure shown in FIG. 1 is adopted, it takes time to raise and lower the temperature, and the processing time of the semiconductor wafer per batch is shortened. It is not possible.
[0028]
Therefore, the ceramic heater 1 of the present invention has a thickness of 5 mm or less, preferably 2 mm or less. By disposing such a thin ceramic heater 1 in the apparatus shown in FIG. 1, it is possible to greatly shorten the time required for temperature rise and temperature drop of the semiconductor wafer 2.
[0029]
In the apparatus shown in FIG. 1, a predetermined film is formed on the surface of the semiconductor wafer 2 by the supplied gas while the semiconductor wafer 2 is rapidly heated from above and below by the ceramic heater 1 and heated uniformly. Alternatively, etching is performed on the surface of the semiconductor wafer 2. After the reaction is completed, the semiconductor wafer 2 is rapidly cooled by stopping energization of the heater circuit pattern 11 of the ceramic heater 1.
[0030]
An exhaust port 300 is provided for exhausting the inside of the chamber 100, and a temperature measuring tube 400 is provided for measuring the temperature inside the chamber 100, and a thermocouple 401 is inserted therein.
[0031]
FIG. 2 is a conceptual cross-sectional view showing one embodiment of the ceramic heater of the present invention. As shown in FIG. 2, a heater circuit pattern 11 made of a conductive layer is formed on one surface of a ceramic sintered body 10a such as an aluminum nitride sintered body. Another ceramic sintered body 10b is arranged on one surface of the ceramic sintered body 10a on which the heater circuit pattern 11 is formed, and the ceramic sintered bodies 10a and 10b are interposed with an adhesive layer 12 interposed therebetween. And join. In this way, the ceramic heater 1 is configured.
[0032]
FIG. 3 is a sectional view conceptually showing another embodiment of the ceramic heater of the present invention. As shown in FIG. 3, a heater circuit pattern 11 made of a conductive layer is formed on one surface of a ceramic sintered body 10a such as an aluminum nitride sintered body. A protective layer 13 is formed on the ceramic sintered body 10 a so as to cover the surface of the heater circuit pattern 11. In this way, the ceramic heater 1 is configured.
[0033]
【Example】
Example 1
Yttrium oxide (Y) as a sintering aid in aluminum nitride (AlN) powder ₂ O _Three ) Was added to 2% by mass and PVB (polyvinyl butyral) as a binder, dispersed and mixed, and then formed into a plate shape using a doctor blade method so as to have a thickness of 1.0 mm after sintering. After drying this molded body, it was punched into a disk shape so that the outer diameter after sintering was 350 mm. The punched molded body was degreased in a nitrogen gas stream at a temperature of 800 ° C. and then sintered at a temperature of 1800 ° C. for 4 hours. The upper and lower surfaces of the obtained sintered body were polished using diamond abrasive grains. Thus, the aluminum nitride sintered compact base material was produced. The obtained aluminum nitride sintered body has a thermal conductivity of 170 W / mK and a thermal expansion coefficient of 4.5 × 10. ^-6 / ° C.
[0034]
On one surface of a single aluminum nitride sintered base, tungsten powder and Al are formed as a heater heating circuit pattern. ₂ O _Three -SiO ₂ What knead | mixed the baking aid of the type | system | group with the ethyl cellulose binder was printed and apply | coated. The printed pattern was a spiral pattern having a line width of 1.0 mm and a line interval of 1.0 mm. The aluminum nitride sintered body on which the printed pattern was formed was degreased in nitrogen gas at a temperature of 800 ° C., and then baked in nitrogen gas at a temperature of 1700 ° C. to form a conductive layer (base material A).
[0035]
On the other hand, 10 masses of ethyl cellulose binder is added to one surface of another aluminum nitride sintered base material in which 5 mass% of Yb—Nd—Ca—O-based oxide powder is added to aluminum nitride powder. % Paste was applied by printing and then degreased at an atmospheric temperature of 500 ° C. The surface of the aluminum nitride layer coated on the aluminum nitride sintered base material (base material B) was superposed on the surface of the aluminum nitride sintered base material on which the conductive layer was formed (lamination specimen 1). ). Furthermore, the aluminum nitride sintered compact base material B which apply | coated the aluminum nitride layer on this lamination | stacking specimen 1 was piled up respectively 1 sheet and 3 sheets, and it was set as the lamination | stacking specimens 2 and 3, respectively. Each of these specimens was fixed with a jig made of molybdenum, and bonded in nitrogen gas at a temperature of 1650 ° C. with a weight placed thereon, thereby producing a ceramic heater. The thickness of the heater is 2 mm for each of the overlapped specimen 1 (two base materials in total), the same specimen 2 (three base materials in total), and the same specimen 3 (five base materials in total). 3 mm and 5 mm. Adhesive layer is 4.5 × 10 ^-6 It was configured to have a coefficient of thermal expansion of / ° C.
[0036]
A set of heater units composed of six heaters having the same thickness obtained by the above procedure was prepared for each heater thickness. These units are placed in a semiconductor manufacturing apparatus as shown in FIG. 1, and after placing a silicon (Si) wafer between the heaters, a voltage of 200 V is applied to the heater heating circuit in nitrogen gas at a pressure of 66.5 Pa. When the temperature was raised, it took 2 minutes, 4 minutes, and 9 minutes in order from the room temperature to the temperature of 600 ° C. in order of the units with the thin heaters. The temperature drop time after turning off was almost the same.
[0037]
(Comparative Example 1)
Using the same method as in Example 1, one aluminum nitride sintered base A having a conductive layer formed on the surface and five aluminum nitride sintered base B having an aluminum nitride layer applied thereto were produced. The aluminum nitride sintered base material on which the conductive layer was formed and the aluminum nitride sintered base material on which the aluminum nitride layer was applied were superposed in the same manner as in Example 1, and an aluminum nitride layer was applied on both sides thereof. It joined by arrange | positioning and inserting | pinching the aluminum nitride sintered compact base material. Thus, the ceramic heater was produced so that the thickness after joining might be 6 mm.
[0038]
When the temperature of the ceramic heater was raised by applying a voltage of 200 V to the heater heating circuit in nitrogen gas at a pressure of 66.5 Pa, it took 12 minutes from room temperature to 600 ° C.
[0039]
(Example 2)
Silicon nitride (Si _Three N _Four ) Yttrium oxide (Y ₂ O _Three 2% by mass and aluminum oxide (Al ₂ O _Three 2% by mass), PVB (polyvinyl butyral) as a binder was added and dispersed and mixed, and then formed into a plate shape using a doctor blade method so that the thickness after sintering was 1.0 mm. After drying this molded body, two disk-shaped molded bodies were prepared by punching with a mold so that the outer diameter after sintering was 350 mm. These molded bodies were degreased in a nitrogen gas stream at a temperature of 800 ° C. and then sintered at a temperature of 1750 ° C. for 4 hours. The upper and lower surfaces of the obtained two sintered bodies were polished with diamond abrasive grains. The obtained sintered body has a thermal conductivity of 80 W / mK and a thermal expansion coefficient of 3.0 × 10. ^-6 / ° C.
[0040]
A paste in which 10% by mass of an ethylcellulose binder was added to a sintered powder base material and tungsten powder and an Al—Si firing aid was printed as a heater heating circuit pattern. The printed pattern was a spiral pattern with a line width of 1.0 mm and a line interval of 1.0 mm. The sintered body on which the conductor pattern was formed was degreased in nitrogen gas at a temperature of 800 ° C. and then baked in nitrogen gas at a temperature of 1700 ° C. (base material A). Further, a paste in which 5% by mass of a Y—Al—O-based oxide powder and 10% by mass of an ethyl cellulose binder was added to an aluminum nitride powder was printed and applied onto another sintered base material. The sintered body was degreased at an atmospheric temperature of 500 ° C. (base material B). Thereafter, the base material B is overlaid on the base material A on which the conductive layer pattern is formed, fixed with a jig made of molybdenum, and a weight is placed thereon and bonded in nitrogen gas at a temperature of 1650 ° C. A ceramic heater having a thickness of 2 mm was produced. The thermal expansion coefficient of the adhesive layer is 4.5 × 10 ^-6 / ° C.
[0041]
A set of heater units composed of six heaters having the same thickness obtained as described above was produced. After placing this unit in a semiconductor manufacturing apparatus as shown in FIG. 1, when a voltage of 200 V was applied to the heater heating circuit in nitrogen gas at a pressure of 66.5 Pa, the temperature was raised from room temperature to 600 ° C. It took 3 minutes to become. The temperature drop time after turning off was almost the same.
[0042]
(Example 3)
Add 2% by mass of magnesium oxide (MgO) as a sintering aid to aluminum oxynitride (AlON) powder, add PVB (polyvinyl butyral) as a binder, disperse and mix to a thickness of 1.0 mm after sintering. It shape | molded by the doctor blade method so that it might become. After drying this molded body, two disk-shaped molded bodies were produced by punching with a mold so that the outer diameter after sintering was 350 mm. These molded bodies were degreased in a nitrogen stream at a temperature of 800 ° C. and then sintered at a temperature of 1770 ° C. for 4 hours. The upper and lower surfaces of the obtained two sintered bodies were polished with diamond abrasive grains. The obtained sintered body has a thermal conductivity of 50 W / mK and a thermal expansion coefficient of 5.0 × 10. ^-6 / ° C.
[0043]
A paste obtained by adding 10% by mass of an ethylcellulose binder to a tungsten powder and an Al—Si firing aid was printed on the obtained sintered base material. The printed pattern was a spiral pattern with a line width of 0.5 mm and a line interval of 0.5 mm. The sintered base material on which the conductive layer pattern of the heater heating circuit was printed was degreased in nitrogen gas at a temperature of 800 ° C. and then baked in nitrogen gas at a temperature of 1700 ° C. (base material A). Moreover, the aluminum nitride powder was printed on the other sintered compact base material (base material B). After degreasing this sintered base material B at a temperature of 500 ° C., it is superposed on the surface of the base material A on which the conductive layer pattern is formed, fixed with a jig made of molybdenum, and a weight is placed on the surface at a temperature of 1600 ° C. A ceramic heater having a thickness of 2 mm was manufactured by bonding in a nitrogen gas. The thermal expansion coefficient of the adhesive layer is 4.5 × 10 ^-6 / ° C.
[0044]
A set of heater units composed of six ceramic heaters obtained in this manner was produced. After this unit is placed in a semiconductor manufacturing apparatus as shown in FIG. 1, a voltage of 200 V is applied to the heater heating circuit in nitrogen gas at a pressure of 66.5 Pa, and the temperature is raised from room temperature to 600 ° C. It took 6 minutes. The temperature drop time after turning off was almost the same.
[0045]
(Example 4)
Zirconium oxide (ZrO ₂ ) Yttrium oxide (Y ₂ O _Three 2% by mass) and 1% by mass of calcium oxide (CaO), and PVB as a binder and dispersed and mixed using a doctor blade method so that the thickness after sintering becomes 1.0 mm And formed into a plate shape. After drying this molded body, two disk-shaped molded bodies were produced by punching with a mold so that the outer diameter after sintering was 350 mm. These molded bodies were degreased in a nitrogen stream at a temperature of 800 ° C. and then sintered at a temperature of 1450 ° C. for 4 hours. The upper and lower surfaces of the two obtained sintered bases were polished with diamond abrasive grains. The sintered body has a thermal conductivity of 10 W / mK and a thermal expansion coefficient of 8.5 × 10. ^-6 / ° C.
[0046]
A paste obtained by adding 10% by mass of an ethylcellulose binder to a tungsten powder and an Al—Si firing aid was printed on the obtained sintered base material. The printed pattern was a spiral pattern with a line width of 1.0 mm and a line interval of 1.0 mm. The sintered base material on which the conductor pattern of the heater heating circuit was printed was degreased in nitrogen gas at a temperature of 800 ° C. and then baked in nitrogen gas at a temperature of 1700 ° C. (base material A). In addition, the thermal expansion coefficient is 4.5 × 10 4 on the other sintered body substrate. ^-6 Aluminum nitride powder at / ° C was printed. This sintered base material was degreased at a temperature of 500 ° C. (base material B). Thereafter, the base material B is superposed on the surface of the base material A on which the conductive layer pattern is formed, fixed with a jig made of molybdenum, and a weight is placed thereon and joined in nitrogen gas at a temperature of 1500 ° C. Thus, a ceramic heater was produced. The thickness of the heater was 2 mm.
[0047]
A set of heater units composed of six obtained ceramic heaters was produced. After placing this unit in a semiconductor manufacturing apparatus as shown in FIG. 1, when a voltage of 200 V was applied to the heater heating circuit in nitrogen gas at a pressure of 66.5 Pa, the temperature was raised from room temperature to 600 ° C. It took 9 minutes. The temperature drop time after turning off was almost the same.
[0048]
(Examples 5 to 8)
The aluminum nitride sintered compact base material A which formed the conductive layer of the same shape and the same spiral pattern with the same method as Example 1 was prepared.
[0049]
In Example 5, a paste containing molybdenum as a main component was applied onto one sintered body and baked at a temperature of 1700 ° C. to obtain a substrate A.
[0050]
In Example 6, a paste mainly composed of silver-palladium (Ag—Pd) was applied on one sintered body and baked at a temperature of 850 ° C. to obtain a substrate A.
[0051]
In Example 7, a paste containing silver-platinum (Ag—Pt) as a main component was applied onto one sintered body and baked at a temperature of 850 ° C. to obtain a substrate A.
[0052]
In Example 8, a paste mainly composed of nickel-chromium (Ni-Cr) was applied onto one sintered body and baked at a temperature of 800 ° C. to obtain a substrate A.
[0053]
As described above, an aluminum nitride sintered base material on which a conductive layer pattern of the heater heating circuit was formed was prepared.
[0054]
In each of the examples, a B-Si-O-based glass was coated on another aluminum nitride sintered base material and degreased in the atmosphere at a temperature of 600 ° C. (base material). B).
[0055]
In Example 5, the aluminum nitride sintered base material A on which the conductive layer pattern was formed and the aluminum nitride sintered base material B on which the glass was applied were superposed and fixed with a molybdenum jig, and the weight was fixed. The ceramic heater was produced by joining in nitrogen gas of 1650 degreeC in the mounted state. In Examples 6 to 8, the aluminum nitride sintered body base A on which the conductive layer pattern was formed and the aluminum nitride sintered body base B on which glass was applied were superposed and fixed with a jig made of molybdenum. A ceramic heater was manufactured by bonding in a nitrogen gas at a temperature of 750 ° C. in a state where was placed. The thermal expansion coefficient of the adhesive layer formed in Example 5 is 4.5 × 10. ^-6 / ° C. The thermal expansion coefficient of the adhesive layers formed in Examples 6 to 8 was 5.0 × 10. ^-6 / ° C.
[0056]
A set of heater units each composed of six ceramic heaters obtained in each of Examples 5 to 8 was produced. After this unit was placed in the semiconductor manufacturing apparatus as shown in FIG. 1, the temperature was increased by applying a voltage of 200 V to the heater heating circuit in nitrogen gas at a pressure of 66.5 Pa. It took 3 minutes from room temperature to 600 ° C. The temperature drop time after turning off was almost the same.
[0057]
(Examples 9 to 12)
An aluminum nitride sintered base material having the same shape was produced in the same manner as in Example 1.
[0058]
A paste containing tungsten as a main component was applied onto one sintered body substrate and baked at a temperature of 1700 ° C. Thus, the sintered compact base material A which formed the conductive layer pattern of the heater heating circuit of the same shape as Example 1 was prepared.
[0059]
An Al—Si—O-based glass was applied onto another aluminum nitride sintered base material to obtain a base material B.
[0060]
In Example 9, the thermal expansion coefficient of the glass is 2.0 × 10. ^-6 / ° C. In Example 10, the thermal expansion coefficient of the glass is 3.0 × 10. ^-6 / ° C. In Example 11, the thermal expansion coefficient of the glass is 8.0 × 10. ^-6 / ° C. In Example 12, the thermal expansion coefficient of the glass is 9.0 × 10 ^-6 / ° C.
[0061]
In each of Examples 9 to 12, the aluminum nitride sintered base material A on which the conductive layer pattern was formed and the aluminum nitride sintered base material B on which the glass was applied were overlapped and fixed with a jig made of molybdenum, A ceramic heater was fabricated by bonding in a nitrogen gas at a temperature of 1100 ° C. with a weight placed.
[0062]
A set of units each composed of six ceramic heaters obtained in Examples 9 to 12 was produced. After this unit was placed in the semiconductor manufacturing apparatus as shown in FIG. 1, the temperature was increased by applying a voltage of 200 V to the heater heating circuit in nitrogen gas at a pressure of 66.5 Pa. It took 3 minutes to reach 600 ° C from room temperature. The temperature drop time after turning off was almost the same. Moreover, when the heat cycle test which hold | maintains alternately for 15 minutes each between room temperature and the temperature of 800 degreeC was performed using each ceramic heater of Examples 9-12, base material A in each of Examples 9-12 The number of cycles at which fine cracks started to occur near the boundary between B and B was 300, 1000, 1000, and 700.
[0063]
(Examples 13 and 14)
Aluminum nitride sintered bases A and B having the same size were prepared in the same manner as in Example 1.
[0064]
A paste containing tungsten as a main component was applied onto one aluminum nitride sintered compact substrate and baked at a temperature of 1700 ° C. In this way, an aluminum nitride sintered base material A in which the conductive layer pattern of the heater heating circuit was formed was produced.
[0065]
On the surface of the aluminum nitride sintered base material on which the conductor pattern is formed, a paste mainly composed of aluminum nitride (AlN) is used in Example 13, and silicon nitride (Si) is used in Example 14. _Three N _Four 3) was applied and fired in nitrogen gas at temperatures of 1650 ° C. and 1550 ° C. to form a protective layer as shown in FIG. The thermal expansion coefficient of the protective layer formed in Example 13 is 4.5 × 10. ^-6 The thermal expansion coefficient of the protective layer formed in Example 14 is 3.0 × 10. ^-6 / ° C.
[0066]
A set of heater units each composed of six ceramic heaters obtained in Examples 13 and 14 was produced. After placing this unit in a semiconductor manufacturing apparatus as shown in FIG. 1, when a voltage of 200 V was applied to the heater heating circuit in nitrogen gas at a pressure of 66.5 Pa, the temperature was raised from room temperature to 600 ° C. It took 1.5 minutes and 2 minutes respectively. The temperature drop time after turning off was almost the same.
[0067]
Moreover, when the heat cycle test was performed between the same room temperature as Example 9-12 and the temperature of 800 degreeC using the ceramic heater obtained in Example 13 and 14, in any Example, it was based on 1000 times. No cracks or the like were observed at the interface between the materials A and B.
[0068]
(Example 15)
A heater unit was manufactured by arranging six ceramic heaters manufactured in Example 1 at predetermined intervals as shown in FIG. This heater unit was incorporated in a CVD apparatus as shown in FIG. When a silicon wafer 2 having a diameter of 300 mm was placed between the ceramic heaters 1 and a voltage was applied to the ceramic heaters 1 to raise the temperature, it took 2 minutes from room temperature to 600 ° C. The in-plane thermal uniformity of the silicon wafer was ± 0.5 ° C.
[0069]
In the apparatus shown in FIG. 1, silane (SiH) is introduced into the chamber 100 as a reaction gas from a gas inlet 200. _Four ) And a reaction on the surface of the silicon wafer 2 to form a silicon film by a CVD method.
[0070]
On the other hand, after raising the temperature from room temperature to 600 ° C. over 20 minutes using a conventional CVD apparatus as shown in FIG. 4, silane is supplied into the chamber and a silicon film is formed on the silicon wafer by the CVD method. did.
[0071]
When the film thickness uniformity and defects of the silicon films formed using the respective apparatuses shown in FIGS. 1 and 4 were compared, they were almost the same.
[0072]
(Comparative Example 2)
100 silicon wafers were set in the conventional apparatus shown in FIG. 4 and heated from the outside of the chamber in a nitrogen gas atmosphere. When a silicon wafer in nitrogen gas having a pressure of 66.5 Pa was heated from the outside of the chamber with a heater with an output of 200 W, it took 20 minutes from room temperature to 600 ° C.
[0073]
(Comparative Example 3)
Yttrium oxide (Y) as a sintering aid in aluminum nitride powder ₂ O _Three 2% by mass), a binder is further added, dispersed and mixed, dried, and then formed into two discs with a die press so that the sintered shape is a disc having an outer diameter of 350 mm and a thickness of 10 mm. Was made. On the surface of one aluminum nitride molded body, a molybdenum wire having a diameter of 0.5 mm was arranged in a coil shape. The winding diameter of the coil was 5 mm and the pitch was 10 mm to form a spiral coil. A ceramic heater was manufactured by placing another aluminum nitride molded body on one surface of the aluminum nitride molded body on which the coiled wire was arranged, and performing hot press sintering at a temperature of 1800 ° C. The obtained sintered body has a thermal conductivity of 173 W / mK and a thermal expansion coefficient of 4.5 × 10. ^-6 / ° C.
[0074]
The ceramic heater thus obtained was placed in the same CVD apparatus as in Example 15 and heated at a voltage of 200 V applied to the wire in nitrogen gas at a pressure of 66.5 Pa. It took 30 minutes to reach 600 ° C.
[0075]
The embodiments and examples disclosed above are exemplarily shown in all points, and should be considered as not restrictive. The scope of the present invention is shown not by the above-described embodiments and examples but by the scope of claims, and includes all modifications and changes within the meaning and scope equivalent to the scope of claims.
[0076]
【The invention's effect】
As described above, according to the present invention, it is possible to rapidly raise the temperature of a semiconductor wafer to a predetermined temperature in a semiconductor manufacturing apparatus, to uniformly heat the reaction, and to rapidly lower the temperature to room temperature after completion of the reaction. A ceramic heater unit can be provided. Therefore, the throughput can be improved even in the production of a small quantity and a variety of products by custom production such as the production of a semiconductor device for logic IC or the like, and the production cost can be reduced.
[Brief description of the drawings]
FIG. 1 is a diagram conceptually showing one embodiment of a semiconductor manufacturing apparatus according to the present invention.
FIG. 2 is a sectional view conceptually showing one embodiment of a ceramic heater for a semiconductor manufacturing apparatus according to the present invention.
FIG. 3 is a sectional view conceptually showing another embodiment of a ceramic heater for a semiconductor manufacturing apparatus according to the present invention.
FIG. 4 is a diagram conceptually showing a conventional semiconductor manufacturing apparatus.
[Explanation of symbols]
1: Ceramic heater, 10a, 10b: Ceramic sintered body, 11: Heater circuit pattern, 12: Adhesive layer, 13: Protective layer.

Claims (9)

A ceramic sintered body substrate;
A plurality of ceramic heaters for a semiconductor manufacturing apparatus, each having a thickness of 5 mm or less, provided with a conductive layer for forming a heater circuit pattern on the ceramic sintered body base material, are arranged at predetermined intervals,
The conductive layer is formed on the surface of the ceramic sintered body base material, and further includes a protective layer formed to cover the surface of the conductive layer,
The protective layer contains 50% by mass or more of either aluminum nitride or silicon nitride,
A ceramic heater unit for a semiconductor manufacturing apparatus, wherein a semiconductor wafer to be processed is disposed between the plurality of ceramic heaters.   The ceramic heater unit for a semiconductor manufacturing apparatus according to claim 1, wherein the thickness of the ceramic heater is 2 mm or less.   The ceramic heater unit for a semiconductor manufacturing apparatus according to claim 1 or 2, wherein the ceramic includes one selected from the group consisting of aluminum nitride, silicon nitride, aluminum oxide, aluminum oxynitride, and silicon carbide.   The ceramic heater unit for a semiconductor manufacturing apparatus according to claim 3, wherein the ceramic includes aluminum nitride.   5. The ceramic for a semiconductor manufacturing apparatus according to claim 1, wherein the conductive layer includes at least one selected from the group consisting of tungsten, molybdenum, silver, palladium, platinum, nickel, and chromium. Heater unit. 6. The semiconductor manufacturing apparatus according to claim 1 , wherein the protective layer has a thermal expansion coefficient of 3.0 × 10 ⁻⁶ / ° C. or more and 8.0 × 10 ⁻⁶ / ° C. or less. Ceramic heater unit. Includes a ceramic heater unit according to any of claims 1 to 6, placing the semiconductor wafer to be processed among a plurality of the ceramic heater, a semiconductor manufacturing device. 8. The semiconductor manufacturing apparatus according to claim 7 , further comprising a ceramic heater unit in which the plurality of ceramic heaters are arranged so that a lower portion of the semiconductor wafer is heated by heat conduction and an upper portion of the semiconductor wafer is heated by radiation and heat conduction. The semiconductor manufacturing apparatus according to claim 7 or 8 , which is used for any one process selected from the group consisting of a CVD process, a plasma CVD process, and a high temperature etching process.

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