JP2006173601A - Semiconductor manufacturing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor manufacturing apparatus having an electrode component that is improved so that oxidation resistance may be raised. <P>SOLUTION: This invention is related to an electrode component 11 for power supply that is used for the semiconductor manufacturing apparatus where a wafer is mounted on a susceptor 1 made of ceramics and the wafer is heated by heating the foregoing susceptor 1, and is also used for supplying power to the foregoing susceptor 1 from the outside. Regarding the electrode component 11 for power supply, its coefficient of thermal expansion is not less than 3.0×10<SP>-6</SP>/K and not more than 8.0×10<SP>-6</SP>/K for room temperature to 500°C, electrical conductivity in room temperature is no more than 10<SP>-3</SP>Ωcm, and a weight increase caused by oxidation in an atmosphere at 500°C is not more than 0.1% per hour. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention also generally relates to a semiconductor manufacturing apparatus, and more specifically, a semiconductor manufacturing apparatus and a liquid crystal substrate used for plasma CVD, reduced pressure CVD, metal CVD, insulating film CVD, ion implantation, etching, and the like. It relates to a manufacturing apparatus.

  Conventionally, in a semiconductor manufacturing process, for example, in a CVD method or etching, a semiconductor wafer is mounted on a susceptor, and the mounted wafer is heated by heating the susceptor. For this reason, a susceptor generally includes a heater circuit for heating a wafer, an electrostatic chuck electrode for closely attaching the wafer to the susceptor, or an RF electrode for generating plasma as required. Has been. Furthermore, various electrode structures for feeding power to these electric circuits from the outside have been proposed.

  For example, Japanese Patent Application Laid-Open No. 11-12053 discloses an electrode structure using molybdenum as an electrode material. In this prior art, an embedded member made of a metal containing molybdenum is embedded in a ceramic member, and in a structure in which the embedded member in the ceramic member and the metal joint member are joined, air or the like is operated for a long time in a high temperature region. There has been proposed a structure that does not cause erosion or insulation failure of the embedded member even if exposed to the above.

Japanese Patent Application Laid-Open No. 10-273371 discloses joining of electrodes by active metal brazing. According to this method, a predetermined bonding strength can be obtained by controlling the “flowability” of the brazing material to the electrode.
JP-A-11-12053 JP-A-10-273371

However, in the technique disclosed in the above Japanese Patent Application Laid-Open No. 11-12053, there are too many brazed parts, and if there is a place where brazing is insufficient even at one place, the atmosphere leaks and oxidation of the electrode occurs. However, there was a part with poor reliability, and there were problems such as a decrease in yield during manufacturing.

  Further, in the technique disclosed in Japanese Patent Laid-Open No. 10-273371, when a “stack” of brazing material is generated between the metal member and the ceramic in the joint, the thermal expansion coefficient between the brazing material and the ceramic (AlN). Due to this difference, after brazing or when a heat cycle test was carried out, cracks occurred on the ceramic side, bonding strength was significantly reduced, and there were parts that lacked reliability, such as breaking from the bonded part .

  The present invention has been made to solve the above-described problems, and it is an object of the present invention to provide a semiconductor manufacturing apparatus using a power supply electrode member with improved oxidation resistance.

  A semiconductor manufacturing apparatus according to the present invention includes a susceptor made of ceramics, on which a wafer is mounted. An electric circuit is embedded in the susceptor. A recess is provided on the other surface of the susceptor so as to expose the external power connection terminal of the electric circuit. A power supply electrode member is fitted in the recess. The electrode member for electric power feeding is electrically connected to the said external power supply connection terminal of the said electric circuit. A glass sealing material is provided across the exposed surface of the power supply electrode member and the other surface of the susceptor so as to prevent outside air from entering the recess.

  Wiring is connected to the power supply electrode member. Electricity is supplied from the wiring to the electric circuit through the power supply electrode member and the power supply terminal.

  According to a preferred embodiment of the present invention, there is further provided an anchor member provided in the recess, one end of which is screwed into the power supply electrode member, and the other end fixed to the bottom of the recess.

According to a further preferred embodiment of the present invention, the power supply electrode member has a coefficient of thermal expansion from room temperature to 500 ° C. of 3.0 × 10 ⁻⁶ / K or more and 8.0 × 10 ⁻⁶ / K or less. The electric conductivity at room temperature is 10 ⁻³ Ωcm or less, and the weight increase due to oxidation in the atmosphere at 500 ° C. is 0.1% / hour or less.

Specific examples of the substance that satisfies the above characteristics include titanium diboride, silicon carbide-zirconium boride composite, molybdenum-zirconium oxide composite, and the like. These materials are preferable because they have a coefficient of thermal expansion of 3 to 8 × 10 ⁻⁶ / K, and further, the electrical conductivity and characteristics due to weight increase due to oxidation at 500 ° C. satisfy the above conditions.

  In addition, as a material satisfying the above characteristics, a metal or alloy mainly composed of tungsten or molybdenum and nickel, gold, or nickel-gold plated on the surface thereof can be used. When these metals or alloys containing tungsten or molybdenum as the main component are left in the atmosphere at 500 ° C., an oxide film is formed on the surface. Therefore, they cannot be used as electrodes, but oxidation-resistant nickel or gold is used on the surface. The above characteristics can be satisfied by plating.

  Examples of ceramics that form the susceptor include aluminum nitride, silicon nitride, silicon carbide, and aluminum oxide. Among these, since aluminum oxide is a relatively inexpensive material, a susceptor can be manufactured at low cost. Furthermore, aluminum nitride and silicon carbide have a merit that the thermal conductivity is high, and when a heater circuit is formed in the susceptor, the temperature distribution tends to be uniform. In addition, since silicon nitride has high strength, ceramics are less likely to be damaged by thermal shock in response to rapid temperature rise and fall.

  In addition, these power supply electrode materials can be directly bonded to the ceramic forming the susceptor because the coefficient of thermal expansion is relatively close to that of the ceramic. By doing so, it is possible to prevent oxidation of power supply components such as tungsten and molybdenum.

  Furthermore, when these materials are used as power supply electrodes, the electrode surfaces can be plated. For example, it is preferable to apply Ni plating, Au plating, and further Ni—Au plating because the oxidation resistance can be further improved and the electrical conductivity can be improved to some extent.

  According to a preferred embodiment of the present invention, the electric circuit is selected from the group consisting of a heater circuit, a high frequency electrode, and an electrostatic chuck electrode.

  In the semiconductor manufacturing apparatus according to the present invention, since the thermal expansion coefficients of the glass sealing material, the power supply electrode member, and the susceptor 1 are close to each other, it is possible to prevent the occurrence of these cracks.

Embodiments of the present invention will be described below with reference to the drawings.
Embodiment 1
FIG. 1 is a schematic cross-sectional view of the semiconductor manufacturing apparatus according to the first embodiment.

  The semiconductor manufacturing apparatus includes a susceptor 1 made of ceramics. A wafer 2 is mounted on one surface of the susceptor 1. An electric circuit such as an RF / electrostatic chuck electrode 3 and a heater circuit 9 is embedded in the susceptor 1.

  A recess 4 is provided on the other surface of the susceptor 1 so as to expose the external power connection terminal of the electric circuit. A wiring 13 is connected to the electric circuit through the recess 4. The susceptor 1 is fixed to the bottom of the vacuum chamber 7 by a shaft 6 with an O-ring 20 interposed. The thickness t of the susceptor 1 is, for example, 3 to 20 mm. The inside of the vacuum chamber 7 is normally evacuated. The inside of the shaft 6 is exposed to the atmosphere.

  FIG. 2 is a plan view of the susceptor 1. The wafer 2 is placed on a recess 8 provided on the surface of the susceptor 1. The wafer 2 is fixed on the recess 8 by the electrostatic force.

The shaft 6 is usually made of the same material as that of the susceptor 1 and is made of, for example, AlN / Al ₂ O ₃ / SiC.

  Next, a detailed structure will be described with reference to FIG. 3 which is an enlarged view of a connection portion between the wiring 13 and the electric circuit, for example, a portion A in FIG.

  Referring to FIG. 3, a recess 4 is provided on the other surface of susceptor 1 so as to expose external power supply connection terminal 9 a of heater circuit 9. A washer 10 that is connected to the external power supply connection terminal 9 a of the heater circuit 9 and functions as a power supply terminal is fitted in the recess 4. A power supply electrode member 11 is provided so as to cover the recess 4. The power supply electrode member 11 is electrically connected to the washer 10 by an anchor member 12.

  One end of the anchor member 12 is screwed into the washer 10, further screwed into the power supply electrode member 11, and the other end is fixed to the bottom of the recess 4. The fixing of the other end of the anchor member 12 and the bottom of the recess 4 will be described later.

  As described above, the power supply electrode member 11 includes a bowl-shaped wall member 11 a whose concave portion faces the concave portion 4 of the susceptor 1. A bowl-shaped wall member 11a covers the concave portion 4 of the susceptor 1 so as to seal the washer 10 and the anchor member 12 from the outside air. The recess 4 of the susceptor 1 is provided with a step 4a for receiving the edge of the wall member 11a. The power supply electrode member 11 is screwed into the wiring 13.

  A glass sealing material 15 is sealed across the exposed surface of the power supply electrode member 11 and the other surface of the susceptor 1 so that outside air does not enter the recess 4. The heater circuit is energized from the wiring 13 through the power supply electrode member 11 and the washer 10. An arrow 14 in the figure indicates a path along which current flows.

The thermal expansion coefficient of the power supply electrode member 11 from room temperature to 500 ° C. is selected to be 3.0 × 10 ⁻⁶ / K or more and 8.0 × 10 ⁻⁶ / K or less. When the thermal expansion coefficient is less than this, the difference in thermal expansion coefficient from the ceramic forming the susceptor becomes large, so that the glass sealing portion in close contact with the ceramic (thermal expansion coefficient of glass: 3.0 to 8.00 × 10 ^{− 6} / K) is not preferable because a crack occurs, the outside air enters the power supply electrode member 11, and the power supply components 10 and 12 are oxidized.

Further, as the material of the power supply electrode member 11, a material having an electric conductivity of 10 ⁻³ Ωcm or less at room temperature is selected. When the electric conductivity is higher than this, it is not preferable because when the electricity is supplied to the electric circuit 9, the power supply electrode member 11 generates heat and may disturb the thermal uniformity of the susceptor 1.

  Further, as the material of the power supply electrode member 11, a material whose weight increase due to oxidation at 500 ° C. is 0.1% / hour or less is selected. Since the power supply electrode member 11 is used in the atmosphere, if the oxidation proceeds at a speed higher than this, the electrode begins to oxidize and deteriorates when the susceptor 1 is used, and eventually electricity stops flowing or is difficult to flow. This is not preferable because adverse effects such as abnormal heating of the oxidized portion are manifested.

  Specifically, at least one of titanium diboride, silicon carbide-zirconium boride composite, and molybdenum-zirconium oxide composite is selected as the main component of the power supply electrode member 11.

  Further, as the material of the power supply electrode member 11, a material made of a metal or alloy mainly containing tungsten or molybdenum and having a surface plated with nickel, gold, or nickel-gold can be used.

  Furthermore, the main component of the ceramic forming the susceptor 1 is selected from aluminum nitride, silicon nitride, silicon carbide, and aluminum oxide.

  These selections are based on the idea that the material of the glass sealing material is first selected so as to match the thermal expansion coefficient of the susceptor, and the material of the electrode member for feeding is selected so as to match the thermal expansion coefficient of the glass sealing material. Is based. That is, the occurrence of these cracks is prevented by bringing the thermal expansion coefficients of the glass sealing material 15, the power supply electrode member 11, and the susceptor 1 close to each other.

Embodiment 2
4 is a diagram showing a further specific aspect of the semiconductor manufacturing apparatus according to the second embodiment in the vicinity of part A of the apparatus of FIG.

  3 that are the same as or correspond to those in FIG. 3 are denoted by the same reference numerals, and description thereof will not be repeated. The same applies to the drawings describing Embodiments 3 to 6 described below.

  In the first embodiment, the example in which the step of receiving the edge of the wall member 11a is provided in the concave portion of the susceptor is shown, but the present invention is not limited to this. That is, as shown in FIG. 4, a step may not be provided in the concave portion 4 of the susceptor, and the edge portion of the wall member 11 a may be in contact with the flat portion of the other surface of the susceptor 1.

Embodiment 3
FIG. 5 is a cross-sectional view of the vicinity of part A of the apparatus of FIG. 1 according to the third embodiment. In the present embodiment, the other end of the anchor member 12 and the bottom of the concave portion 4 are fixed by screws 16. Even in such an embodiment, the same effects as in the first embodiment can be obtained.

Embodiment 4
FIG. 6 is a cross-sectional view of the vicinity of part A of the apparatus of FIG. 1 according to the fourth embodiment. In the present embodiment, the other end of the anchor member 12 and the bottom of the recess 4 are fixed by the glassing 17. Even in such an embodiment, the same effects as in the first embodiment can be obtained.

Embodiment 5
FIG. 7 is an enlarged view of a portion A of the semiconductor device according to the fifth embodiment in the device of FIG.

  Referring to FIG. 7, power supply electrode member 11 is fitted in recess 4. The power supply electrode member 11 is directly electrically connected to the external power supply connection terminal 9 a of the heater circuit 9. That is, in this embodiment, the washer 10 used in the apparatus of FIG. 3 is omitted. A glass sealing material 15 is sealed across the exposed surface of the power supply electrode member 11 and the other surface of the susceptor 1 so that outside air does not enter the recess 4. A wiring 13 is connected to the power supply electrode member 11. Electric power is supplied from the wiring 13 directly to the heater circuit 9 through the power supply electrode member 11. Even in such an embodiment, the same effects as in the first embodiment can be obtained.

Embodiment 6
FIG. 8 is an enlarged view of part A of FIG. 1 of the semiconductor manufacturing apparatus according to the sixth embodiment.

  Although the anchor member 12 is used in the fifth embodiment, the anchor member is also omitted in the present embodiment. Power is supplied from the wiring 13 to the heater circuit 9 through the power supply electrode member 11. Even in such an embodiment, the same effects as in the first embodiment can be obtained.

Examples of the present invention will be described below.
Example 1
First, the manufacturing method of the ceramic used for this invention is demonstrated.

  A slurry was prepared by adding a binder and a solvent to the powder having the composition ratio shown below and mixing them with a ball mill.

Composition _{1 ... AlN: 95wt% -Y 2} O 3: 5wt%
Composition 2 ... Si ₃ N ₄ : 95 wt% -Y ₂ O ₃ : 2.5 wt% -Al ₂ O ₃ : 2.5 wt%
Composition _{3 ... Al 2 O 3: 98wt} % -CaO: 1.0wt% -MgO: 1.0wt%
Composition _{4 ... SiC: 98wt% -B 2} O 3: 2.0wt%
A green sheet was produced from this slurry by the doctor blade method. Next, the produced green sheet was cut so that the size after sintering was a circle having a diameter of 350 mm. A heater circuit was formed on the cut sheet using a W paste by a screen printing method.

  Next, a sheet on which a heater circuit is formed is laminated with a plurality of sheets that are not formed with a heater circuit, and further, an RF electrode and an electrostatic chuck electrode are laminated by screen printing W paste, Degreased in nitrogen at 700 ° C.

  Next, composition 1 was sintered at 1800 ° C. in a nitrogen atmosphere, composition 2 was sintered at 1700 ° C. in a nitrogen atmosphere, composition 3 was sintered at 1600 ° C. in a nitrogen atmosphere, and composition 4 was sintered at 2000 ° C. in a nitrogen atmosphere to prepare a susceptor.

  Next, the granule was produced from the slurry of the said compositions 1-4 by the spray-drying method. A cylindrical molded body was produced from the finished granule by a dry press method. This was degreased at 700 ° C. in a nitrogen stream and sintered under the same conditions as in the sheet sintering. Thereafter, a cylindrical member having an inner diameter of 50 mm, an outer diameter of 60 mm, and a length of 200 mm was manufactured by machining the completed cylindrical sintered body. This cylindrical molded body is used as a shaft 6 with reference to FIG.

Referring to FIG. 1, a slurry of Al ₂ O ₃ —Y ₂ O ₃ —AlN is applied to one surface of this tubular member 6 and brought into close contact with susceptor 1. The member 6 and the susceptor 1 were joined. At this time, all of the power supply terminal portions 10, 11, and 12 for feeding the heater circuit 9 and the RF / electrostatic chuck electrode 3 from the outside can be installed in the cylindrical member 6.

  Thereafter, W or molybdenum as the power feeding component 10 was connected to the electric circuit 9 by an active metal brazing containing titanium. Titanium diboride, a silicon carbide-zirconium boride composite, and a molybdenum-zirconium oxide composite were attached to the power supply electrode member 11, and these electrode materials were sealed with glass 15. Thereafter, nickel was attached to each electrode material as a power supply member (wiring) 13 to complete the susceptor 1.

  At this time, the power supply terminal 10, the electrode 11, and the power supply member 13 were mechanically connected by screws. Thereafter, the completed susceptor 1 was set in the chamber 7 and a film was formed on the silicon wafer 2. At this time, the temperature of the susceptor 1 was 500 ° C., and the atmosphere in the shaft 6 was air. As a result, the silicon wafer 2 could be processed without any problems with each electrode material. However, a thin oxide film was formed on each material.

Example 2
A susceptor 1 was produced by the same method as described above. However, regarding the electrode material at this time, each material was subjected to nickel plating, Au plating, or nickel-Au plating. As a result, as in Example 1, each electrode material was able to be processed without any defects, and no oxide film was formed.

Example 3
A susceptor 1 was produced in the same manner as in Example 1. However, as the electrode material at this time, tungsten or molybdenum was used, and nickel or Au plated ones were used. The conditions are summarized in Table 1.

  As a result, similarly to Example 1, each electrode material could be processed without any defects.

Comparative Example 1
A susceptor was produced by the same method as described above. However, the electrode material used at this time was tungsten or nickel. As a result, tungsten was not able to process the silicon wafer because the electrode was oxidized during the temperature rise of the susceptor. Regarding nickel, cracks were formed in the glass at the time of glass sealing, and tungsten serving as the power supply terminal was oxidized, and the silicon wafer could not be processed.

  In the above-described embodiment, the heater circuit is described as an example of the electric circuit. However, the same effect can be obtained even when the electric circuit is a high-frequency electrode and an electrostatic chuck electrode.

  It should be understood that the embodiments and examples disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

1 is a sectional view of a semiconductor manufacturing apparatus according to a first embodiment. 2 is a plan view of a susceptor used in the semiconductor manufacturing apparatus according to Embodiment 1. FIG. It is the A section enlarged view of the apparatus of FIG. 1 based on Embodiment 1. FIG. FIG. 4 is an enlarged view of a part A of the apparatus in FIG. 1 according to the second embodiment. FIG. 6 is an enlarged view of part A of the apparatus of FIG. 1 according to Embodiment 3. FIG. 6 is an enlarged view of part A of the apparatus of FIG. FIG. 10 is an enlarged view of a part A of the apparatus of FIG. It is the A section enlarged view of the FIG. 1 apparatus based on Embodiment 6. FIG.

Explanation of symbols

  Reference Signs List 1 susceptor, 2 wafer, 3 RF (electrostatic chuck) electrode, 4 recess, 6 shaft, 7 vacuum chamber, 9 heater circuit, 9a heater circuit external power connection terminal, 10 washer, 11 power supply electrode member, 12 anchor Member, 13 Wiring, 14 Current flow.

Claims (4)

A susceptor made of ceramics, on which a wafer is mounted,
An electrical circuit embedded in the susceptor;
A recess provided on the other surface of the susceptor to expose an external power connection terminal of the electric circuit;
A power supply electrode member that fits into the recess and is electrically connected to the external power connection terminal of the electrical circuit;
A glass sealing material that is provided across the exposed surface of the power supply electrode member and the other surface of the susceptor, and seals the gap so that outside air does not enter the recess,
Wiring connected to the power supply electrode member,
A semiconductor manufacturing apparatus that supplies electricity to the electric circuit from the wiring through the power supply electrode member and the power supply terminal.   The semiconductor manufacturing apparatus according to claim 1, further comprising an anchor member provided in the recess, one end of which is screwed into the power supply electrode member, and the other end fixed to the bottom of the recess. The electrode member for power supply has a thermal expansion coefficient of 3.0 × 10 ⁻⁶ / K or more and 8.0 × 10 ⁻⁶ / K or less from room temperature to 500 ° C.,
The electrical conductivity at room temperature is 10 ⁻³ Ωcm or less,
The semiconductor manufacturing apparatus according to claim 1, wherein an increase in weight due to oxidation in the atmosphere at 500 ° C. is 0.1% / hour or less.   The semiconductor manufacturing apparatus according to claim 1, wherein the electric circuit is selected from the group consisting of a heater circuit, a high-frequency electrode, and an electrostatic chuck electrode.

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