Abstract:
A semiconductor manufacturing equipment is provided herein. The semiconductor manufacturing equipment includes a heater element configured to heat a wafer, a first connection part and a second connection part integrated with the heater element, a first electrode electrically contacted with and fixed to the first connection part on a first surface of the first electrode, and a second electrode electrically contacted with and fixed to the second connection part on a second surface of the second electrode. The second surface is perpendicular to the direction of the first surface, and the heater element produces heat by applying a voltage between the first electrode and the second electrode.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2006-83517 filed on Mar. 24, 2006, the entire contents of which are incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a heater to heat, from a rear surface in forming a film onto, for example, a semiconductor wafer, and relates to semiconductor manufacturing equipment. 
     2. Description of the Related Art 
     In recent years, with miniaturizing semiconductor manufacturing equipment, high film-forming uniformity in its manufacturing process has been required. A rear surface heating system used for chemical vapor deposition (CVD) device such as an epitaxial growth device, having no heating source above a wafer, and enabling a reaction gas to flow in a vertical direction, can form a uniform film. 
     In such a rear surface heating system, a resistance heating heater being used as the heating source, the heater must be stable in high temperature (above 1300° C. at a heater temperature), and also must be highly-pure (heating with fewer pollutants). Therefore, for instance, a SiC material etc. is used as a heater element material in order to be stable and not to cause low metal-staining in high temperatures. 
     A heater element like this, as described in [0019] and FIG. 10 of Jpn. Pat. Appln. Publication No. 10-208855, is fixed to a heater support body  18  with bolts. However, it presents problems such that a connection surface at a fixed position adjacent to the heater element to be heated in high temperatures cause surface roughness due to variations in heat or gas and increases connection resistance. 
     For instance, if there are deviations in the height and position of the heater support body  18 , and in the dimensions of a heater, using a hard material with low flexibility, such as a SiC material, poses the problems that it is difficult to correct the deviations, and it is impossible to surely fix the heater. In addition, failures are generated, such as a bad electrical contact between heater and electrode, heating and thermal degradation due to electric field concentration at a connection part, or damage of a heater caused by thermal stresses. 
     SUMMARY OF THE INVENTION 
     An object of the present invention is to provide semiconductor manufacturing equipment capable of connecting a heater for heating a rear surface to an electrode certainly at an optimum position, and to provide a heater. 
     Semiconductor manufacturing equipment according to an aspect of the invention includes a heater element configured to heat a wafer, a first connection part and a second connection part which are integrated with the heater element, configured to apply voltages to the heater element, a first electrode contacted with and fixed to the first connection part on a first surface of the first electrode configured to be to apply a voltage to the first connection part, a second electrode which is contacted with and fixed to the second connection part on a second surface of the second electrode, configured to apply a voltage to the second connection part, and the second surface is perpendicular to the direction of the first surface. 
     Further, Semiconductor manufacturing equipment according to an aspect of the invention includes a heater element configured to heat a wafer, a first connection part and a second connection part configured to apply voltages to the heater element, both of the connection parts integrated with the heater element, a first electrode contacted with and fixed to the first connection part on a first surface of the first electrode configured to be to apply a voltage to the first connection part, a second electrode contacted with and fixed to the second connection part on a second surface of the second electrode configured to apply a voltage to the second connection part, openings prepared in the first and the second connection parts, and the first and the second electrodes, respectively, a first bolt configured to fix the first connection part and the first electrode by passing though the opening of the first connection part, the first bolt having smaller diameter than the opening of the first connection part, and a second bolt which has smaller diameter than the opening of the second connection part, configured to fix the second connection part and the second electrode by passing through the opening of the second connection part. 
     Further, A heater according to an aspect of the invention includes a heater element configured to heat a wafer from a rear surface, a first connection part which is integrated with the heater element, configured to apply voltages to the heater element, a second connection part which is integrated with the heater element, configured to apply voltages to the heater element, and the second surface is perpendicular to the direction of the first surface. 
     Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention, and together with the general description given above and the detailed description of the embodiments given below, serve to explain the principles of the invention. 
         FIG. 1  is a cross-section view showing the semiconductor manufacturing equipment relating to the first embodiment of the present invention; 
         FIG. 2  is a perspective view showing the heater relating to an embodiment of the present invention; 
         FIG. 3  is a side view showing the heater shown in  FIG. 2 ; 
         FIG. 4  is a drawing showing another pattern of a heater element relating to an embodiment of the present invention; 
         FIG. 5  is a drawing showing a connection part and a connecting portion of an electrode relating to an embodiment of the present invention; 
         FIG. 6  is a drawing showing connection parts and connecting portions of the electrodes relating to an embodiment of the present invention; 
         FIG. 7  is a cross-section view showing the semiconductor manufacturing equipment relating to another embodiment of the present invention; 
         FIG. 8  is a perspective view showing the heater relating to another embodiment of the present invention; and 
         FIG. 9  is a side view showing the heater shown in  FIG. 8 . 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     Embodiments of the present invention will be described with reference to the drawings hereinafter. 
     First Embodiment 
       FIG. 1  depicts a cross-section view of semiconductor manufacturing equipment of the first embodiment. A reaction chamber  2  to which a wafer  1  is guided, as shown in  FIG. 1 , is provided with a gas supply port  3  to supply a reaction gas consisting of a film-forming gas and a carrier gas from above the reaction chamber  2 , and with a gas discharge port  4  to discharge the reaction gas from below the reaction chamber  2 . A rotational driving means  5  to rotate the wafer  1  and a ring-shaped (or “annular-shaped”) holder  6  to hold the wafer at its outer circumference portion on the driving means  5  are disposed in the reaction chamber  2 . Further, an in-heater  7  is installed therein to heat the wafer  1  from below. 
       FIG. 2  depicts a perspective view of the in-heater  7 , and  FIG. 3  depicts its side view. As shown in the views, the in-heater  7  is integrally structured with welding, etc., of a resistance-heating-type heater element  11  composed of, for instance, a SiC based material, and of a pair of connection parts  12   a  and  12   b . With regard to the pattern of the heater element  11 , an example is shown in Figures, any type of the pattern can be used if uniformly heating to a semiconductor substrate and corresponding to a change in temperature are possible. As for another pattern, for example, a heater element  11 ′ with a pattern shown in  FIG. 4  is available. 
     The connection parts  12   a  and  12   b  are fixed with bolts  13   a  and  13   b  composed of the SiC based material, etc., so as to come into surface contact with electrodes (booth bars)  14   a  and  14   b . At this moment, a contact surface between the lower part of the connection parts  12   a  and the electrode  14   a , and a contact surface between the lower part of the connection part  12   b  and the electrode  14   b  are different in surface direction by 90°. The electrodes  14   a  and  14   b  are fixed to electrode rods  15   a  and  15   b  with bolts, respectively, and connected, through the electrode rods  15   a  and  15   b , to a temperature control mechanism (not shown) to electrically control temperatures. A heater shaft  16  ( FIG. 1 ) holds the electrode rods  15   a  and  15   b , and the upper part of the heater shaft  16  and the head sections of the electrodes rods  15   a  and  15   b  make play therebetween. 
       FIG. 5  shows the connecting section of the connection part  12   a  and the electrode  14   a . As shown in  FIG. 5 , the connection part  12   a  has an opening  18   a . The diameter of the opening  18   a  is set to, for example, 7.5 mm in comparison to the standardized diameter 6 mm of the bolt  13   a . That is, a tolerance of ±0.75 mm is allowed, and in the range, the fixed position of the connection part  12   a  and the electrode  14   a  can be moved in a contact surface direction. Therefore, if the dimension tolerance of the heater element is within ±0.2 mm, and the attachment dimension tolerance of the electrode is within ±0.5 mm, the fixed position falls with in a movable range. Similarly, in the connection part  12   b  and the electrode  14   b , with the similar tolerances are allowed, the fixed position being movable in its contact surface direction, any deviation in an in-plane direction and a height direction of the heater element  11  can be corrected if the fixed position is within the movable range. 
     In terms of the positional relationship between the connection part and the electrode, it is enough for the movable range in both directions of the in-plane direction and the height direction of the heater element, and it is not limited to the present embodiment. For instance, as shown in  FIG. 6 , between a connection part  12   a ′ and an electrode  14   a ′ and between a connection part  12   b ′ and an electrode  14   b ′ may be fixed with a bolt  13   a ′ and  13   b ′, respectively. 
     Like this manner, fixing between the connection part and the electrode at a position away from the heater element by a certain distance makes it possible to restrain a change resulted from heat and gas at the connection part caused by an increase in temperature at the contact surface. By fixing each connection part and each electrode of the heater in addition to the correction of the deviations, secure connection is achieved, and a failure, such as a defective connection between the connection part of the heater and the electrode or damage of the heater, can be suppressed. Fine adjustment of the heater position in a vertical direction becoming possible, optimizing the positions makes an improvement of uniformity of film thickness of formed coating. Further, providing play on a heater shaft side holding the electrode rods enables responding to the positional variations of the electrodes resulted from such a structure. 
     Second Embodiment 
       FIG. 7  illustrates a partial cross-section view of semiconductor manufacturing equipment of the present embodiment. The embodiment differs, from the first embodiment, in having, in addition to an in-heater  27   a , an out-heater  27   b  to heat a ring-shaped holder  26 . 
       FIG. 8  depicts a perspective view of the out-heater  27   b , and  FIG. 9  depicts its side view. As shown in Figures, in a like manner in the first embodiment, the out-heater  27   b  is integrally structured with welding, etc., of a resistance-heating-type heater element  31  made of, for instance, a SiC based material, and of a pair of connection parts  32   a  and  12   b.    
     Connection parts  32   a  and  32   b  are fixed so as to come into surface contact with electrodes  34   a  and  34   b  with bolts  33   a  and  33   b  made of the SiC based material. The electrodes  34   a  and  34   b , in a similar way in the first embodiment, are connected to a temperature control mechanism (not shown) to electrically control temperatures through electrode rods (not shown) held to heater shafts (not shown), respectively. 
     Like the first embodiment, the connection parts  32   a  and  32   b  each has openings. The diameter of each opening is set to, for example, 7.5 mm, and in comparison to the standardized diameter 6 mm of each bolt  33   a  and  33   b , tolerances are allowed in a similar manner in the first embodiment. Therefore, the fixed position between the connection part  32   a  and the electrode  34   a  can be moved in a contact surface direction. 
     In the second embodiment, the out-heater is shaped in a ring; its electrodes are formed on the same plane. Therefore, the contact surface at which the lower part of the connection part  32   a  is contacted with the electrode  34   a  is substantially same as the contact surface at which the lower part of the connection part  32   b  is contacted with the electrode  34   b  in the surface direction. Because the variations of the electrode positions due to heater, etc., are restrained almost only in the surface direction. However, to adjust the dimension difference, etc., in the surface direction and the vertical direction, like the first embodiment, the surface direction may be different by 90°. It is not always necessary for the electrodes to be formed on the same plane, as similar way in the first embodiment; they may be formed to face each other. In such a case, like the first embodiment, it is needed for both directions to be different by 90°. 
     According to this manner, fixing the connection parts and the electrodes at the positions away from the heater element by certain distances enables suppressing changes due to heat and gas at the connection parts caused from the increase in temperature at the contact surfaces. In addition to the correction of the deviations, by fixing between each connection part and each electrode of the heater, as is the case of the first embodiment, the second example can obtain assure connection and suppress a failure such as a connection fault and damage. Becoming possible to finely adjust the heater position in the vertical direction, by optimizing the position, it becomes possible, in the similar manner in the first embodiment, to improve the film thickness uniformity of the coating to be formed. Further, just like the first embodiment, providing the play on the heater shaft side holding the electrode rods enables responding to the variations of the positions of the electrodes resulted from such a structure. 
     Using the SiC based material for a heater element material, so long as a material which does not cause low-temperature pollution at high temperatures and is stable, the material is not specially limited, and using, for example, a carbon material, a material in which SiC coating is performed onto the carbon material or a SiC material, and a high-melting point metal material such as Ir is available. For the bolt, the SiC material like the heater element material being used, the material similar to the heater element material or the electrode material is preferable. 
     The opening diameter of the connection part having set to 7.5 mm compared with the bolt diameter 6 mm, and the tolerance having set to ±0.75 mm, the tolerance can be appropriately set in response to the bolt diameter. It is preferable for the opening diameter to be set to 10-20% of the bolt diameter. If the tolerance is too large, the stability of the connection cannot be secured. On the contrary, if the tolerance is too small, the deviation due to the tolerance of the dimension and the position cannot be corrected. 
     These embodiments make it possible for the heater for the rear surface heating of the semiconductor substrate to surely connect to the electrode at the optimum position. Accordingly, these embodiments can make the coating forming process onto the semiconductor substrate, and can uniform the thickness of the film formed on the semiconductor substrate. In the wafer formed by this semiconductor manufacturing equipment, and the semiconductor device formed through an element forming process and an element isolating process, it becomes possible to stabilize yield and an electron property. Especially, these embodiments are effective for applying to a thick film forming process of a power semiconductor device such as a Power MOSFET and an IGBT (insulated gate bipolar transistor) in which thick films on the order of several 10 μm through 100 μm are used for an N-type base region, P-type base region, insulating isolation region, etc. 
     Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to specific details and representative embodiments shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.