JP2006100755A - Substrate processing equipment and electric heater for substrate processing equipment, and substrate processing equipment equipped with this - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make a heating element long in life by suppressing a generation of heat strain of a heating element, and by preventing the heating element from contacting with each other and with a structure of liner tube or the like simultaneously in a substrate processing equipment and an electric heater for the substrate processing equipment. <P>SOLUTION: The equipment comprises a processing chamber processing by housing a substrate 12, and a heating arrangement 2, having a heating element 43, heating inside of the processing chamber with the heating element. The heating element is held in only one end by a holding portion. And, the heating element is formed so that at least one portion may be profiled in convex toward the substrate. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a substrate processing apparatus for manufacturing a semiconductor device on a substrate such as a silicon wafer and a glass substrate, an electric heater for the substrate processing apparatus, and a substrate processing apparatus including the same.

  As a device for manufacturing a semiconductor device, there is a substrate processing apparatus that performs processing such as generation of a thin film, annealing treatment, impurity diffusion, etching, etc. on a substrate such as a silicon wafer, a glass substrate, etc. Alternatively, there are a single-wafer type substrate processing apparatus that processes a plurality of sheets and a batch type substrate processing apparatus that processes a predetermined number of sheets at a time. As a batch type substrate processing apparatus, there is a vertical substrate processing apparatus having a vertical furnace or a horizontal substrate processing apparatus having a horizontal furnace.

Hereinafter, there is a batch type substrate processing apparatus having a vertical furnace as a conventional substrate processing apparatus, for example, one disclosed in Patent Document 1. With reference to FIG. 22, a vertical furnace 1 of a conventional substrate processing apparatus will be described.
A cylindrical heating device 2, a soaking tube 3 inside the heating device 2, and reaction tubes 4 are provided concentrically inside the soaking tube 3, and a boat 5 is inserted into the reaction tube 4. The boat 5 holds wafers 12 in multiple stages in a horizontal posture, and is placed on an elevator cap 7 via a boat cap 6. The elevator cap 7 is provided on a boat elevator (not shown) and can be raised and lowered.

  A gas introduction tube 8 is communicated with the upper end of the reaction tube 4, and an exhaust port 9 is provided at the lower end of the reaction tube 4. The lower end of the gas introduction pipe 8 is connected to a gas supply pipe 10, and the exhaust port 9 is connected to an exhaust pipe 11.

  With the boat 5 pulled out from the reaction tube 4, a required number of wafers 12 are held by the boat 5, and the boat 5 is raised by the boat elevator (not shown) and loaded into the reaction tube 4. To do. The inside of the reaction tube 4 is heated to a predetermined temperature by the heating device 2, a reaction gas is introduced into the reaction tube 4 through the gas supply tube 10 and the gas introduction tube 8, and a thin film is generated on the surface of the wafer 12. The gas after the reaction is exhausted through the exhaust port 9 and the exhaust pipe 11.

Next, the heating device 2 will be described with reference to FIGS.
Cylindrical peripheral heat insulating materials 15 and 16 are provided concentrically with the reaction tube 4, and the upper ends of the peripheral heat insulating materials 15 and 16 are closed by a ceiling heat insulating material 17. The outer surface of the surrounding heat insulating material 15 is covered with a heater case (not shown).

  A holding member 18 extending in the vertical direction is provided at a position of the inner wall of the surrounding heat insulating material 16 equally divided in the circumference. The holding member 18 includes a plurality of holding pieces 19 made of high alumina (containing 94.2% alumina) connected in the vertical direction, and holding holes 22 are formed between the holding pieces 19 and the holding pieces 19. A heating wire 21 to be described later is inserted into the holding hole 22.

  A heating wire 21 that is a heating element is provided so as to surround the soaking tube 3, the heating wire 21 has a circular cross section and is coiled, and the heating wire 21 passes through the holding hole 22, The holding member 18 is supported at a position where the circumference is equally divided.

  During the film forming process on the wafer 12 in the vertical furnace 1, the heating wire 21 generates heat and expands, so that the coil diameter of the heating wire 21 is expanded, and the holding member 18 has the vertical furnace 1. A force acts in the direction opposite to the center, and the holding member 18 moves together with the heating wire 21 in the direction opposite to the center of the vertical furnace 1. Further, the surrounding heat insulating material 16 also becomes hot and expands due to the heat generated by the heating wire 21.

  When the heating wire 21 stops generating heat after the film formation process is completed, the temperature of the heating wire 21 drops and the diameter of the coil contracts, so that the holding member 18 has a force in the center direction of the vertical furnace 1. The holding member 18 moves in the central direction of the vertical furnace 1 together with the heating wire 21. Further, the surrounding heat insulating material 16 also shrinks due to the temperature drop due to the temperature drop of the heating wire 21.

  Each time the wafer 12 is subjected to a film forming process in the vertical furnace 1, the temperature in the vertical furnace 1 is repeatedly raised and lowered, and the heating wire 21 and the surrounding heat insulating material 16 are expanded as described above. Repeat the contraction.

  In the above-described conventional heating apparatus, the relative displacement in the circumferential direction between the holding pieces is not restricted due to the structure of the holding pieces, so that the heating wire and the heat insulating material are expanded by repeatedly raising and lowering the temperature in the furnace. , Repeated shrinkage, the holding piece is pulled out from the heat insulating material, and the relative displacement in the circumferential direction occurs between the holding pieces, the connection between the holding pieces is disconnected, the heating wires come into contact with each other, and a short circuit accident occurs There is a risk of doing.

Also, due to the expansion and contraction of the heating wire, the heating wire moves with the holding piece in the radial direction of the vertical furnace, or deforms irregularly due to thermal strain, and when the deformation is in the circumferential direction, the heating wires contact each other. If the deformation is in the radial direction, the heating wire may come into contact with the conductive soaking tube.
JP 11-67424 A

  In view of such circumstances, the first object of the present invention is to suppress the generation of thermal distortion of the heating wires, and prevent the heating wires from contacting the heating wires or structures such as the soaking tubes. The purpose is to extend the service life.

  A second object of the present invention is to provide an electric heater for a substrate processing apparatus capable of performing more uniform heating and a substrate processing apparatus provided with the same. A third object of the present invention is to provide an electric heater for a substrate processing apparatus capable of reliably supporting a heating element and a substrate processing apparatus having the same.

  In order to achieve the first object, the present invention includes a processing chamber for storing and processing a substrate, and a heating device that has a heating element and heats the processing chamber by the heating element. Only the substrate is held by the holding unit, and the substrate processing apparatus is formed so that at least a part thereof is convex toward the substrate.

  In order to achieve the second and third objects, the electric heater for a substrate processing apparatus according to the present invention is characterized in that the upper end of the serpentine heating element is fixed to a support and the lower end of the heating element is moved up and down. The upper end and the lower end are brought close to each other and the intermediate portion of the heating element is separated from the insulator. Since the upper end and the lower end are close to each other, the distance between the heating elements is not increased, and more uniform heating is possible. In this case, it is desirable to separate the lower end from the insulator rather than the upper end of the heating element.

  When fixing the heating element, a bent portion may be formed on the upper end of the heating element, and the bent portion may be hooked on the support. In this case, the bent portion may be bent at a substantially right angle, and the hooking portion of the support may be formed at a substantially right angle for receiving the bent portion. For example, the latching portion is substantially parallel to the lower wall portion and the lower wall portion on which the bent portion is hooked, and the upper wall portion and the bent portion are prevented from falling off in the horizontal direction to prevent the bent portion from being pulled upward. And a horizontal wall portion that hangs down from the upper wall portion, so that the lower wall portion can be divided into the upper wall portion and the horizontal wall portion.

A first insulating piece for preventing a short circuit of the heating element between the upper release slits may be interposed in the bent portion of the upper release slit of the heating element.
In order to fix the heating element by other means, the support for fixing the upper end of the heating element may be passed through the lower release slit of the heating element. In this case, the support passes through an insulating piece interposed between the heating element and the insulator.

  The lower end side of the heating element may be held by an insulator in such a manner that a lower fixing body (pin) passes through the slit and is movable in the slit longitudinal direction and restricted in the movement in the slit vertical direction.

In each of the above features, the lower end of the upper heating element may be overlapped with the support supporting the upper end of the lower heating element in the horizontal direction. In addition, a curved portion may be formed on the upper side of the heating element so that a part of the heating element is suspended while providing an offset distance with respect to the heat dissipation side between the upper end and the lower end of the heating element. Furthermore, you may curve so that the intermediate part of the up-down direction of a heat generating body may protrude on the opposite side to an insulator.
The electric heater described in any of the above features can be implemented as a substrate processing apparatus including the electric heater.

  According to the present invention, there is provided a processing chamber for storing and processing a substrate, and a heating device that has a heating element and heats the processing chamber by the heating element, and the heating element is held only at one end by the holding portion. Since at least a portion is formed to be convex toward the substrate, the buckling phenomenon is prevented even when the heating element becomes hot and the strength is reduced, and when the heating element is thermally expanded, the heating element Due to the convex shape, deformation is induced to the substrate side, and when the heat shrinks, the deformation is absorbed by the convex shape, so that the generation of thermal distortion in the heating elements is suppressed and the heating elements are uniform or between the heating elements. It exhibits excellent effects such as preventing contact with a structure such as a heat tube and extending the life of the heating element.

On the other hand, according to the characteristics of the electric heater for a substrate processing apparatus and the substrate processing apparatus provided with the same according to the present invention, the upper end and the lower end are close to each other, so that heating can be performed uniformly. Further, since the intermediate portion of the heating element is separated from the insulator, the heat dissipation efficiency is good and uniform heating is possible. In addition, the upper end is fixed and the lower end is free, so there is no risk of dropout even if thermal expansion or deformation occurs, and it can be reliably supported and can be manufactured at low cost without requiring assembly accuracy. is there.
Other objects, configurations, and effects of the present invention will become apparent from the following embodiments of the present invention.

The best mode for carrying out the present invention will be described below with reference to the drawings.
First, an outline of a substrate processing apparatus according to the present invention will be described with reference to FIG. In FIG. 1, the same reference numerals as those in FIG.

  A soaking tube 3 and a reaction tube 4 are provided concentrically inside the cylindrical heating device 2, and a processing chamber is formed in the reaction tube 4, and a boat 5 for holding wafers 12 in a horizontal multistage in the processing chamber. The boat 5 can be loaded and withdrawn by a boat elevator (not shown).

  A reaction gas introduction pipe 31 and an exhaust pipe 32 are communicated in the reaction pipe 4, a flow rate controller 33 is provided in the reaction gas introduction pipe 31, and a pressure controller 34 is provided in the exhaust pipe 32, The exhaust gas is discharged so that the reaction gas is introduced at a predetermined flow rate and the inside of the reaction tube 4 is maintained at a predetermined pressure. The boat 5, the boat elevator and the like are the same as those of the conventional substrate processing apparatus described above, and a description thereof is omitted.

  The heating device 2 includes a heat generating part 25 and a heater case 26 that surrounds the heat generating part 25 and forms a cylindrical space 24 between the heat generating part 25, and the heater case 26 functions as an outer heat insulating part. A ceiling portion 27 is provided at the upper ends of the heater case 26 and the heat generating portion 25, and an elbow-shaped exhaust conduit 28 that opens to the lower surface and the side surface is formed in the ceiling portion 27.

A forced exhaust line having an exhaust blower (not shown) that performs forced exhaust is connected to the exhaust conduit 28.
A cooling gas introduction duct 36 is provided so as to surround the lower portion of the heat generating portion 25, and the cooling gas introduction duct 36 communicates with the cylindrical space 24.

  A cooling gas supply line 37 is communicated with the cooling gas introduction duct 36, and a cooling gas supply line 38 is communicated with a soaking tube inner space 39 formed between the soaking tube 3 and the reaction tube 4. Air valves 40 and 41 are provided in the supply lines 37 and 38, respectively.

  The heater case 26 includes a metal heater cover 55 and a cylindrical outer heat insulator 42. The heat generating portion 25 includes a heat generating body 43 and an inner layer heat insulating body 45 that supports the heat generating body 43, and the heat generating body 43 is provided over the entire inner surface of the inner layer heat insulating body 45. A large number of gas blowing holes 46 penetrating the inner layer insulator 45 are formed in the heat generating part 25 in a required distribution, and a furnace space 35 formed between the heat generating part 25 and the heat equalizing tube 3. It communicates with the cylindrical space 24.

As materials of the outer layer heat insulator 42 and the inner layer heat insulator 45, for example, alumina (aluminum oxide: Al ₂ O ₃ ) and silica (SiO ₂ ) are used as main components. The heating element 43 is made of a heat-generating material that can be rapidly heated, for example, an Fe-Al-Cr alloy, and the cross section has a flat plate shape or the like so as to increase the heat-generating surface area.

  As will be described later, the heat generating portion 25 is configured by stacking a plurality of heat generating step portions 57, and the heat generating body 43 is provided for each heat generating step portion 57. As will be described later, the heating element 43 is divided into necessary zones in the axial direction of the heating device 2, and zone control is possible. In each zone, heater temperature detection for detecting the heating temperature of each zone is possible. A vessel 52 is provided. Further, the heating element 43 may have the same heating pattern in each zone by making the molding pattern of each zone the same.

  The processing state of the wafer 12 processed in the reaction tube 4 is controlled by the main controller 47. The main control unit 47 includes a temperature control unit 48 for controlling the temperature in the furnace, a gas flow rate control unit 49 for controlling the flow rate of the processing gas and the cooling gas, and a pressure control unit for controlling the pressure in the reaction tube 4. 50. A drive control unit 51 for controlling a mechanism unit such as the boat elevator is provided.

  A furnace temperature detector 53 is erected along the inner surface of the reaction tube 4. The furnace temperature detected by the furnace temperature detector 53 and the heater temperature detected by the heater temperature detector 52 are as follows. Input to the temperature control unit 48. The opening and closing of the air valves 40 and 41 are controlled by the gas flow rate control unit 49, the gas flow rate control unit 49 controls the gas introduction amount by the flow rate controller 33, and the pressure control unit 50 is controlled by the pressure controller 34. The exhaust pressure is controlled via the pressure to control the pressure in the reaction tube 4.

The heat generating part 25 will be described.
The inner-layer heat insulator 45 is configured by concentrically stacking required steps of a heat insulating member 56 (see FIG. 2), which is a short cylindrical insulator, and covers the inner wall surface of the heat insulating member 56 for each step. 43 is provided. As will be described later, the heating element 43 for each stage is controlled by heating, and the heating element 43 and the heat insulating member 56 constitute a heating stage part 57, and the heating part 25 concentrics the heating stage part 57. It has become a required stacking.

The heat generating step portion 57 will be further described with reference to FIGS.
FIG. 2 shows the lowermost heat generating step portion 57. In FIGS. 2 and 3, 58 indicates a ring-shaped heat insulating portion base as a heat insulating material, and the outer-layer heat insulating body 42 is provided on the heat insulating portion base 58. The inner-layer heat insulator 45 is mounted.

  Support members 59 and 59, which are heater holding portions, are disposed at the lower and upper ends of the heat insulating member 56, respectively. The heater holding portion 59 is further provided with a lower holding member 61 and an upper holding member that is superposed on the lower holding member 61. 62.

  The lower holding member 61 has a ring plate shape, an outer diameter matches the heat insulating member 56, an inner diameter is smaller than the heat insulating member 56, and an inner end (substrate side end, 1) protrudes in a bowl shape toward the inside.

  The upper holding member 62 has a ring plate shape, an outer diameter matches the heat insulating member 56, an inner diameter is smaller than the lower holding member 61, and an inner end portion is the lower holding member. A protrusion 63 is formed on the inner end of the upper holding member 62 and protrudes downward. The inner end of the upper holding member 62 has a hook shape.

  Between the upper holding member 62 and the protrusion 63, a heating element holding groove 64 having a bowl-shaped cross-section opened inward is formed in a ring shape, and the heating element 43 is formed in the heating element holding groove 64. The bent portion 43a is held. The bent portion 43a and the heating element holding groove 64 are formed with appropriate play in both the vertical direction and the radial direction, and the protrusion 63 prevents the bent portion 43a from being pulled out to the center side. Yes.

The heating element 43 will be described with reference to FIG.
The developed shape of the heating element 43 is a twisted shape in which slits 65a and 65b are alternately engraved on both sides of the strip at a predetermined pitch. The bent portion 43a which is the upper end portion of the band plate is bent in the horizontal direction at an obtuse angle slightly larger than a right angle toward the outside, and the bent portion 43a is sandwiched between the lower holding member 61 and the upper holding member 62. Has been.

  A main body portion 43b of the heating element 43 is suspended along the heat insulating member 56, is in contact with the inner end of the upper holding member 62 of the lower heater holding portion 59, and the lower end of the main body portion 43b is restrained. There is no free state. The main body 43b is curved convexly toward the center or bent at an obtuse angle. It should be noted that a part of the main body 43b may be convexly curved toward the center side or bent at an obtuse angle.

  In the state where the heat generating stepped portion 57 is stacked up and down, the lower end of the heating element 43 of the upper heat generating stepped portion 57 is not in contact with or close to the inner end of the upper holding member 62, and the lower heat generating stepped portion Since the gap is formed at least by the protrusion 63 with respect to the upper end of the heating element 43 of 57, the lower end of the upper heating element 43 and the upper end of the lower heating element 43 are not opened or overfilled. Even if the upper heating element 43 extends downward due to thermal expansion, it does not come into contact with the lower heating element 43.

  The heating element 43 is curved along the inner wall surface of the heat insulating member 56, and has a substantially cylindrical shape concentric with the heat insulating member 56 as a whole, and as shown in FIG. A gap is formed between both ends of the heat generating element 43 so that both ends do not come into contact with each other even when the heat generating element 43 expands in the circumferential direction. A temperature control unit 48 is connected, and the connection between the heating element 43 and the temperature control unit 48 is a flexible connection so that both ends can be displaced. The temperature is controlled by the temperature controller 48 independently for each heating element 43 of the heating stage 57.

The operation will be described below.
In the processing of the wafer 12, the boat 5 loaded with the wafer 12 is loaded into the reaction tube 4 by a boat elevator (not shown) and rapidly heated to a predetermined temperature by the heating device 2. While the wafer 12 is heated to a predetermined temperature by the heating device 2, a reaction gas is introduced from the reaction gas introduction pipe 31, exhaust gas is exhausted through the exhaust pipe 32, and a necessary heat treatment is performed on the wafer 12. Made.

  Usually, the temperature of the boat 5 is kept at a required temperature, for example, 550 ° C. before the boat 5 is charged, and after the boat 5 is charged, the temperature is raised to a wafer processing temperature, for example, 850 ° C. In addition, the temperature before loading and the processing temperature are appropriately selected according to the processing content in the substrate processing apparatus.

  The heating stage 57 of each stage of the heating unit 25 is temperature-controlled as an independent zone by the temperature control unit 48, and the heating element 43 of each heating stage 57 is one continuous heating element, When there is an abnormality in the heating element 43, for example, when there is a disconnection, it can be detected immediately, and the deterioration state of the heating element at each stage can be easily grasped.

  The heating element 43 of the heating stage 57 of each stage of the heating part 25 is configured so that no gap is formed between the upper and lower sides, so that no non-heating part is generated. Further, since the heating element 43 is provided up to the lowest heating stage 57, and the heating part 25 has no non-heating part, a uniform temperature-uniforming area in the furnace can be taken, and the uniformity of wafer processing is improved.

  The heat generating element 43 thermally expands due to the heat generated by the heat generating element 43, but the lower end is free, and a gap is formed between the main body 43b and the heat insulating member 56. The thermal deformation of the heating element 43 is free without restraining the thermal strain in the vertical direction. Further, since the bent portion 43a is held with play, there is no restriction in the circumferential direction and the radial direction, and the slits 65a and 65b are formed. The distortion is absorbed by the slits 65a and 65b, and the heat generating body 43 is restrained from generating thermal stress in any of the vertical direction, the circumferential direction, and the radial direction.

  Even if the lower end of the heating element 43 is restrained from thermal expansion in the vertical direction for some reason, since the main body 43b is curved inward, the main body is subject to thermal deformation of the main body. It is induced to bulge further toward the inside, and irregular thermal deformation is prevented from occurring. Further, since only the upper end of the heating element 43 is held, the buckling phenomenon caused by the generated stress is prevented even when the heating element 43 becomes hot and the strength decreases, for example, when the lower end is also restrained. For example, irregular deformation can be prevented. The heating element 43 is bent at the bent portion 43a, and since the strength of the heating element 43 itself is increased, it is difficult to deform.

  When the process is complete, it is rapidly cooled to the wafer exit temperature, eg, 550 ° C. For cooling after the processing of the wafer 12, the air valves 40 and 41 are opened, and an inert gas such as air or nitrogen gas is supplied from the cooling gas supply lines 37 and 38 as a cooling gas.

  The cooling gas from the cooling gas supply line 38 is supplied to the soaking tube inner space 39. The cooling gas from the cooling gas supply line 37 is supplied to the cooling gas introduction duct 36 and introduced into the cylindrical space 24. The flow path from the cooling gas introduction duct 36 to the cylindrical space 24 is not greatly changed in direction, the pressure loss is small, and the flowability of the cooling gas is good. The cooling gas rising in the cylindrical space 24 further flows into the furnace space 35 through the gas blowing holes 46 and further through the slits 65a and 65b, so that the heat generating part 25 can be rapidly moved from both the outer surface and the inner surface. Cool down.

  The cooling gas introduced into the cylindrical space 24 is dispersed through the cooling gas introduction duct 36 having a large volume, so that the cooling gas uniformly flows into the cylindrical space 24 and the occurrence of uneven cooling is prevented. . Although the cooling gas introduction duct 36 itself has a large heat radiation characteristic, the heat insulating portion base 58 is interposed, and the heat transfer coefficient in the radial direction is the same as the other portions. Increase in the amount of heat release is suppressed.

  The cooling gas rises in the cylindrical space 24, the furnace space 35, and the soaking tube space 39 and is exhausted from the exhaust conduit 28. The inner layer insulator 45 is cooled by a cooling gas that rises in the cylindrical space 24 and the furnace space 35, and the soaking tube 3 and the reaction tube 4 ascend the furnace space 35 and the soaking tube space 39. It is cooled rapidly by the cooling gas.

  Thus, the wafer 12 in the reaction tube 4 is rapidly cooled. By adopting a ceramic heating element as the heating element 43, rapid heating and high-temperature heating are possible, and further rapid cooling is possible by cooling the heating device 2 with a cooling gas.

  When the cooling is completed, the boat 5 is lowered by a boat elevator (not shown), and the processed wafers 12 are discharged from the boat 5. In the case of decompression processing, the boat 5 is lowered after the reaction chamber is returned to atmospheric pressure.

  Next, a second embodiment of the present invention will be described with reference to FIGS. In the following embodiments and modifications, members similar to those described above are denoted by the same reference numerals.

  In the lower portion of the present embodiment, an insulator (heat insulating member) 56 is configured by stacking a plurality of divided bodies 56a. A through hole 59a is formed in the support body (heater holding portion) 59, and is fixed to the insulator by an L-shaped fixing nail 59b. A first insulating piece 66, which is a small soot tube (insulator), is inserted into the upper release slit 65b of the bent portion 43a of the heat generator 43 to prevent a short circuit between the heat generators 43 sandwiching the upper release slit 65b. The first insulating piece 66 is housed in a latching portion 74 surrounded by the upper support portion 62 and the lower support portion 61, and is prevented from falling off. A lower insulating pin 52, which is an insulator, passes through the slit 65 at the lower portion of the heat generating body 43, and is movable in the longitudinal direction of the slit 65 and in a state where movement in the vertical direction of the slit 65 is restricted. It is fixed to the insulator 56 through 67. Further, the fixing by the lower fixing pin 52 may be performed at the position of the lower release slit 65a as indicated by reference numeral 52x in addition to the upper release slit 65b.

  In the upper part of FIG. 6, the heating element 43 is suspended and supported by an upper fixing pin 53 that is an insulator. The insulator 56 is formed by stacking second to fourth divided bodies 56b to 56d. The upper fixing pin 53 is passed through each lower release slit 65a, and the heating element 43 is fixed to the insulator 56 via a third insulating piece 68 which is an insulator.

  A gas outlet 69a is formed at an appropriate location between the heating elements 43, 43 by penetrating a nozzle 69 for blowing out gas through the insulator 59. Each gas outlet 69a is located between each heat generating body 43 and 43, and it arrange | positions so that the blown-out gas may not hit the heat generating body 43 directly. As a result, the gas directly hits the heating element 43, so that only a part of the heating element 43 is locally cooled to prevent heat unevenness, and the deterioration of the heating element 43 is prevented.

  In the present embodiment, the heating element 43 is supported by using the bent portion 43 a in the lowermost zone, and the heating element 43 is supported by using the pin 53 in the middle zone. In this manner, the heating element unit (the heating step part) using the bent portion 43a is arranged for the lowermost stage and / or the uppermost zone, and the heating elements using other supports are arranged in the other parts. By arranging it, the temperature tends to fluctuate up to the support body 59 due to the influence of disturbance most in each zone (e.g. heat escape when entering and leaving the boat and heat escape from the lower end opening of the heating device). By providing the heating element 43 in an overlapping manner, the temperature control range can be expanded. Further, for example, when four zones are formed on the upper and lower sides, only one of the zones may be used as the heat generating step portion 57 according to the present invention, or two or three may be used. As a result, it is possible to prevent deterioration of the heating element in the lowermost zone that is likely to be overloaded due to the influence of disturbances in each zone.

  Next, a third embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 9, the electric heater H according to the present invention is roughly a plurality of heating elements 43, a support body 59 that supports the heating elements 43, an insulator that supports the support body 59, and is a heat insulating member. It consists of a certain ceramic board 56.

  The heating element 43 is formed with a plurality of slits 65 intersecting with the longitudinal direction of the heating element 43, and the heating element 43 constitutes a meandering circuit. Further, as shown in FIG. 10A, at one end of the heating element 43, there is provided a bent portion 43a bent substantially at an L shape, that is, bent at a substantially right angle to be hooked on the support body 59. ing. Further, the heating element 43 is continuous in a planar shape with respect to the width direction.

  As shown in FIG. 10A, the support body 59 is formed by forming a substantially L-shaped latching portion 74 between the upper support portion 62 and the lower support portion 61. The hook portion 74 includes a lower wall portion 61a to which the bent portion 43a is hooked, an upper wall portion 62b that is substantially parallel to the lower wall portion 61a and prevents the bent portion 43a from being pulled upward, and a bent portion. A horizontal wall portion 62a that hangs down from the upper wall portion 62b to prevent the horizontal displacement of 43a.

  Since the heat generating body 43 is supported only by the latching portion 74, the heat escape from the heat generating body 43 is suppressed, so that the heat efficiency is good. And since the lower end of the heat generating body 43 overlaps with the support body 59 in the horizontal direction view (or the orthogonal direction Dh to the heat generating surface of the entire electric heater H), it is separated from the ceramic board 56 than the upper end of the heat generating body 43. Even if the heating element 43 is thermally expanded, there is no fear that the upper and lower ends are in contact with each other. In this case, the lower end of the heating element 43 may ride on the horizontal wall portion 62a or may have a gap with the horizontal wall portion 62a. The horizontal distance between the lower end and the upper end of the heating element 43 may be adjusted so that the heating between them is uniformly performed. In addition, the ceramic board 56 which is a heat insulator is continuous in a planar shape with respect to the width direction.

Next, a modified example of the third embodiment of the present invention will be described.
In the modified example shown in FIG. 10B, the shape of the heating element 43 is different from the modified example shown in FIG. A curved portion 73 is formed in the heat generating element 43, and most of the heat generating element 43 is vertically suspended while providing an offset distance with respect to the heat radiation side between the upper end and the lower end of the heat generating element 43.

In the modified example shown in FIG. 10C, the lower end of the heating element 43 does not ride on the lateral wall 62 a and is separated from the support body 59 by the amount of thermal expansion.
In the modified example shown in FIG. 10D, the shape of the lower support portion 61 is different from that in FIG. 10A, and a protrusion 75 that is an insulator is provided at the tip of the adjacent upper support portion 62. The lower support portion 61 is shaped flat, and the protrusion 75 prevents the heating element 43 from being thermally deformed and its lower end protruding from the front side.

  In the fourth embodiment shown in FIGS. 11A and 12, as shown in FIG. 12, the heating element 43, the support body 59 and the ceramic board 56 are curved, and the fixing element 77 causes the heating element to be curved. The third embodiment is different from the third embodiment in that the support body 59 supporting 43 is fixed to the ceramic board 56. As shown in FIG. 11, the fixture 77 includes a bolt 78a, a nut 78b, and a washer 78c, and a support body 59 having a stopper 78d attached at an appropriate interval is attached to a ceramic board 56 to which a stainless steel plate 76 is attached by a bolt 78a. The washer 78c is sandwiched between the bolts 78a and the nuts 78b are fastened and fixed. The support body 59 is increased in strength by being fixed to the ceramic board 56 by a fixing tool 77 at an appropriate interval.

  FIG. 11B shows a modified example of the fourth embodiment. In this modification, the structure of the support is different. The support 79 includes a fixing portion 81 fixed to the ceramic board 56, an adjustment portion 82 that can be inserted into and removed from the fixing portion 81, and a hooking portion 83. The fixing portion 81 is provided with a concave portion 81 a corresponding to the lower wall portion for hooking the bent portion 43 a of the heating element 43, and the adjustment portion 82 is grasped for insertion into and removal from the fixing portion 81. It consists of a knob 82a that functions as a horizontal wall portion and an insertion shaft 82b that functions as an upper wall portion. By adjusting the insertion position of the adjustment portion 82, the insertion shaft 82b serves as an upper wall portion that prevents the bent portion 43a from falling off, and maintenance work such as removal of the heating element 43 is facilitated.

  Next, in the fifth embodiment shown in FIG. 13, as shown in FIG. 13B, the support body 85 is composed of an L-shaped hanger pin 86, a spacer 87, and an insulator 88. 43 is not provided with a bent portion 43a and is formed flat. 13 to 19 use the curved support body 59 and the ceramic board 56 as in the embodiment of FIG. The hanger pins 86 are fixed to the ceramic board 56 so as to have the same height at appropriate intervals, and the heating element 43 is hooked on the hanger pins 86 by the slits 65. The heating element 43 is sandwiched between the spacer 87 attached to the hanger pin 86 and the insulator 88 attached to the protruding portion of the hanger pin 86. Further, the lower end of the heating element 43 is close to the adjacent insulator 88 so as to ride on or overlap with the adjacent insulator 88 and close to the upper end of the heating element 43.

  Here, a modified example of the fifth embodiment will be described with reference to FIGS. In the modified example shown in FIG. 14, the shape of the insulator 88 is different, and the stability of the heating element 43 is enhanced by forming the insulator 88 wider in the horizontal direction.

  In the modified example shown in FIG. 15, the lower end of the heating element 43 is separated from the ceramic board 56 rather than the upper end by the convex portion 56 x provided on the ceramic board 56 without using the insulator 88, and the lower end and the upper end are separated. Are in close proximity.

  In the modified example shown in FIG. 16, a convex portion 56 y having a height different from that of the convex portion 56 x shown in FIG. 15 is provided on the ceramic board 56, and the upper end and the lower end of the heating element 43 are brought close to each other. Furthermore, by using a hanger pin 86 for the convex portion 56x and penetrating the lower end of the upper release slit 65a of the heating element 43, the heating element 43 can move in the longitudinal direction of the slit 65, but the slit moves in the vertical direction. Is regulated by a hanger pin 86.

In the modified example shown in FIG. 17, the upper end and the lower end of the heating element 43 are brought close to each other by an insulator 89 that is a plate-like insulator fixed to the ceramic board 56.
In the modified example shown in FIG. 18, a hanger pin 86 provided with a recess 86 a having substantially the same width as the thickness of the heating element 43 is used, the slit 65 is fitted into the recess 86 a, and the heating element 43 is hooked.

  The sixth embodiment shown in FIG. 19 relates to modification of the shape of the heating element 43. The heating element 43 is deformed toward the ceramic board 56 due to thermal expansion. For this reason, the intermediate portion of the heating element 43 is curved so as to protrude in the opposite direction to the ceramic board 56 so that the intermediate portion in the vertical direction is separated from the ceramic board 56 in advance, thereby preventing the support member from falling off due to deformation. is doing. Furthermore, when the deformation causes the deformation to protrude largely toward the opposite side of the ceramic board 56, the hanger pin 86, which is an insulator, is used to form the slit 65 of the heating element 43. By penetrating and arranging at the most curved part, the deformation of the heating element 43 to the curved side is restricted to a predetermined size.

  The reference embodiment of FIG. 20A is mainly used for a ceiling portion, and the structure of the support is different. The support 90 fixed to the ceramic board 56 via a fixing tool 77 includes a fixing portion 90a fixed to the ceramic board 56 and an adjustment portion 90b that can be inserted into and removed from the fixing portion 90a. The fixing portion 90 a is provided with an insertion portion 91 for latching the bent portions 43 a provided at both ends of the heating element 43. The bent portion 43a is inserted into the insertion portion 91 of the support 90, the adjustment portion 90b is inserted into the fixing portion 90a, and the heating element 43 is fixed.

  FIG. 20B shows a modification of the present embodiment. In this modified example, the support body 92 is fixed to the ceramic board 56 by the fixing member 77 without attaching a clasp. Further, on both sides of the support 92, there are provided insertion portions 94 formed so as to make it easier to attach the heating element. The insertion portion 94 is formed with a recess in the opposite direction to the insertion portion 91 shown in FIG. 20A, and the bent portion 43 a is hooked on the insertion portion 94 to fix the heating element 43. ing.

  Furthermore, in the modified example shown in FIG. 20C, in the curved ceramic board 56, the bent portions 43 a of the heating elements 43 are respectively inserted into the insertion portions 95 provided in the support body 93, and the repulsive force of the heating elements 43 The support 93 is fixed to the ceramic board 56. This modified example can be used not only on the ceiling but also on the wall as long as it is curved.

  In the reference embodiment shown in FIG. 21A, a protrusion 98 that prevents the heating element 43 from falling off due to distortion is provided. The protrusion 98 is provided between the ceramic boards 56 and 56 so that the tip of the protrusion 98 is positioned substantially at the center of the heating element 43, and the tip of the protrusion 98 and the center of the heating element 43 are close to each other. Yes. Therefore, even if the heat generating element 43 is distorted toward the ceramic board 56, the distortion is suppressed by the protruding portion 98, and the heat generating element 43 is removed from the insertion portion 97 in which the upper end portion of the heat generating element 43 is inserted. Can be prevented.

  21 (b) and 21 (c) show modified examples of this embodiment. The modified example shown in FIG. 21B plays the same role as the protruding portion projecting portion 98 by providing the protruding portion 56 z at the substantially central portion of the ceramic board 56. Further, in the modified example shown in FIG. 21C, a slight gap C is provided between the heating element 43 and the ceramic board 56. Due to the gap C, the heat generating element 43 in which distortion due to heat is generated contacts the ceramic board 56z, and the heat generating element 43 can be prevented from falling off due to distortion. In addition, this invention is not limited to the said embodiment, A various change is possible in the range which does not deviate from the summary.

  The electric heater shown in the embodiment of FIGS. 6 to 21 can be used in the substrate processing apparatus shown in FIGS. Further, in each of the above embodiments, in the embodiment of FIGS. 9, 10, 20 (a) and (b), the heating element 43 and the heat insulator 56 are linearly continuous with respect to the longitudinal direction of the heating element 43, and FIGS. 11 to 19, 20 (c), 21, the heating element 43 and the heat insulator 56 are curved and continuous with respect to the longitudinal direction of the heating element 43. However, in the embodiment of FIGS. 9, 10, 20 (a) and (b), the heating element 43 and the heat insulator 56 are curvedly continuous with respect to the longitudinal direction of the heating element 43, and FIGS. In the embodiments of (c) and 21, the heating element 43 and the heat insulator 56 may be linearly continuous with respect to the longitudinal direction of the heating element 43.

In each of the above-described embodiments and modifications, the meandering heater is not limited to a flat plate shape, and a wire rod developed in a meandering shape may be used.
In each of the above embodiments and modifications, the heating element is not only arranged vertically in the vertical direction, but the plane of the heating element may be arranged inclined in the vertical direction or arranged horizontally.

  Examples of the insulating material constituting the support, protrusions, fixing pins, insulating pieces, insulators, etc. include ceramics, silicon carbide, silicon nitride mainly composed of alumina, alumina silica, mullite, zircon, or cordierite. In addition to the above, various materials can be used as long as they are harder and have better heat conductivity than the heat-insulating refractory of the heat insulator. As the heat insulating refractory constituting the heat insulating member (insulator) 56, various materials such as ceramic fibers and ceramic powder mixed with organic / inorganic binder can be used. The kind and the mixing | blending of the material which comprise these heat insulation bodies and a support body can be suitably changed according to the operating temperature etc. of an electric heater.

  A substrate processing apparatus according to the present invention, an electric heater for the substrate processing apparatus, and a substrate processing apparatus provided with the substrate processing apparatus are used for manufacturing a semiconductor device, forming a thin film on a substrate such as a silicon wafer and a glass substrate, annealing, It can be used in a substrate processing apparatus that performs processing such as diffusion and etching, and the electric heater for a substrate processing apparatus of the present invention can be applied from room temperature to heating up to 1400 ° C.

1 is a schematic cross-sectional view of a vertical furnace of a substrate processing apparatus according to an embodiment of the present invention. It is sectional drawing of the lowest step part of the heating apparatus of this vertical furnace. It is sectional drawing of the inner-layer heat insulating body of this heating apparatus. It is a perspective view of the heat generating body of this heating device. It is a schematic plan view which shows the connection state of a heat generating body. 2nd Embodiment of the substrate processing apparatus which concerns on this invention is shown, (a) is a front view of an electric heater, (b) is AA sectional drawing of (a). It is an enlarged view of the support body part of FIG.6 (b). It is a figure which shows the relationship between a heat generating body upper part and an insulation piece. It is a front view of 3rd embodiment of the electric heater applicable to the substrate processing apparatus which concerns on this invention. (A) is BB sectional drawing of FIG. 9, (b)-(d) is sectional drawing which shows the modification of (a). (A) is a figure equivalent to Drawing 10 (a) showing a 4th embodiment of the present invention, and (b) is a sectional view showing a modification of (a). It is CC sectional drawing of Fig.11 (a). (A) is a front view which shows 5th embodiment of this invention, (b) is DD sectional drawing of (a). (A) is a front view which shows the modification of 5th embodiment of this invention, (b) is EE sectional drawing of (a). (A) is a front view which shows the modification of 5th embodiment of this invention, (b) is FF sectional drawing of (a). (A) is a front view which shows the modification of 5th embodiment of this invention, (b) is GG sectional drawing of (a). (A) is a front view which shows the modification of 5th embodiment of this invention, (b) is HH sectional drawing of (a). (A) is a front view which shows the modification of 5th embodiment of this invention, (b) is II sectional drawing of (a). (A) is a front view which shows 6th embodiment of this invention, (b) is JJ sectional drawing of (a). FIG. 10A is a view corresponding to FIG. 10A showing a reference embodiment, and FIGS. 10B and 10C are cross-sectional views showing modified examples of FIG. FIG. 10A is a view corresponding to FIG. 10A showing a reference embodiment, and FIGS. 10B and 10C are cross-sectional views showing modified examples of FIG. It is sectional drawing which shows the conventional substrate processing apparatus. It is a sectional elevation view of the conventional heating device. It is a plane sectional view of the heating device of the conventional example. It is a fragmentary sectional view of the heating device of the conventional example.

Explanation of symbols

H: Electric heater, 2: Heating device, 3: Soaking tube, 4: Reaction tube, 5: Boat, 12: Wafer, 25: Heat generation part, 42: Outer insulation, 43: Heat generation element, 43a: Bending part, 43b: body part, 43x, 43y: terminal, 45: inner layer insulator, 43: heating element, 43a: bent part, 52: lower fixing pin, 53: upper fixing pin, 56: ceramic board (insulator, heat insulating member) ), 56a to d: first to fourth divided bodies, 56x, 56y, 56z: convex portion, 57: heat generating step portion, 59: support, 59a: through hole, 59b: fixing nail, 61: lower support portion, 61a: tip portion, 62: upper support portion, 62a: lateral wall portion, 62b: upper wall portion, 63: ridge, 65: slit, 65a: lower open slit, 65b: upper open slit, 66: first insulating piece, 67: Second insulating piece, 68: Third insulating piece, 69: Nozzle, 72: Edge 73: curved portion, 74: latching portion, 75: protrusion, 76: stainless steel plate, 77: fixing tool, 78a: bolt, 78b: nut, 78c: washer, 78d, 78e: clasp, 79: support, 81: fixing part, 81a: recess (tip part), 82: adjustment part, 82a: knob (lateral wall part), 82b: insertion shaft (upper wall part), 83: latching part, 85: support, 86: hanger Pin, 86a: recess, 87: spacer, 88, 89: insulator, 90: support, 90a: fixing part, 90b: adjustment part, 91: insertion part, 92, 93: support, 94, 95: insertion Part, 96: support, 97: insertion part, 98: protruding part, 100: heater, 101, 101a: heating element, 102: support, 102a: insertion part, 103: molded article

Claims (14)

  A processing chamber that houses and processes the substrate; and a heating device that has a heating element and heats the processing chamber by the heating element, wherein the heating element is held only at one end by a holding portion, at least a part of which is A substrate processing apparatus formed so as to be convex toward a substrate. The upper end of the serpentine heating element (43) is fixed to the support (59), the lower end of the heating element (43) is movable in the vertical direction, and the upper end and the lower end are connected to each other. An electric heater for a substrate processing apparatus, which is brought close to each other and an intermediate portion of the heating element (43) is separated from the insulator (56). The electric heater for a substrate processing apparatus according to claim 2, wherein the lower end of the heating element (43) is separated from the insulator (56) with respect to the upper end. The substrate according to claim 2 or 3, wherein a bent portion (43a) is formed at an upper end of the heating element (43), and the bent portion (43a) is hooked on the support body (59). Electric heater for processing equipment. The bent portion (43a) is bent at a substantially right angle, and the latching portion (74) of the support (59) is also formed at a substantially right angle to receive the bent portion (43a). Item 5. The electric heater for a substrate processing apparatus according to Item 4. The hooking portion (74) is substantially parallel to the lower wall portion (61a) and the lower wall portion (61a) on which the bent portion (43a) is hooked, and prevents the bent portion (43a) from coming out upward. An upper wall portion (72b) and a lateral wall portion (62a) hanging from the upper wall portion (62b) for preventing the bent portion (43a) from falling off in the horizontal direction are provided. The electric heater for a substrate processing apparatus according to claim 5, wherein the wall portion (62b) and the horizontal wall portion (62a) are separable. A first insulating piece (66) for preventing a short circuit of the heating element (43) between the upper release slits (65b) is interposed in the bent part (43a) of the upper release slit (65b) of the heating element (43). The electric heater for a substrate processing apparatus according to claim 4, wherein the electric heater is used. The said support body (59) for fixing the upper end of the said heat generating body (43) penetrates the lower release slit (65a) of the said heat generating body (43), Any one of Claims 2-7 An electric heater for a substrate processing apparatus according to claim 1. 9. The electric for substrate processing apparatus according to claim 8, wherein the support (59) passes through an insulating piece (68) interposed between the heating element (43) and the insulator (56). heater. The lower end side of the heating element (43) is insulated in such a manner that the lower fixing body (52) passes through the slit (11), is movable in the longitudinal direction of the slit (11), and restricts movement in the vertical direction of the slit (11). The electric heater for a substrate processing apparatus according to any one of claims 2 to 9, wherein the electric heater is held by a body (56). The lower end of the upper heating element (43) is overlapped with the support body (59) supporting the upper end of the lower heating element (43) in the horizontal direction, according to any one of claims 2 to 10. The electric heater for substrate processing apparatuses as described. A curved portion (73) is provided on the upper side of the heating element (43) so that a part of the heating element (43) is suspended while providing an offset distance to the heat dissipation side between the upper end and the lower end of the heating element (43). It formed, The electric heater for substrate processing apparatuses in any one of Claims 2-11 characterized by the above-mentioned. The electric heater for a substrate processing apparatus according to any one of claims 2 to 11, wherein an intermediate portion in the vertical direction of the heating element (43) is curved so as to protrude to the side opposite to the insulator (56). The substrate processing apparatus provided with the electric heater for substrate processing apparatuses in any one of Claims 2-13

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