Ceiling heater, method for manufacturing semiconductor device, substrate processing method, and substrate processing apparatus

Abstract

The present invention suppresses the deformation of heating elements.　A ceiling heater provided above a reaction tube includes a disk-shaped base material and heating elements continuously spread on the base material over a plurality of areas obtained by dividing a circle centered at the center of the base material into sectors, wherein each of the heating elements spread over the plurality of areas is connected to the heating element in the adjacent area at a predetermined portion, the base material has a groove corresponding to the shape of the heating elements, a wall is formed by portions other than the portion where the groove is provided, and the space between the heating elements respectively spread over the two regions adjacent to each other is configured to be wider than the width of the wall separating the two regions.

Description

Technical Field

[0001] The present disclosure relates to a ceiling heater, a method for manufacturing a semiconductor device, a substrate processing method, and a substrate processing apparatus.

Background Art

[0002] As one step in the manufacturing process of a semiconductor device, a process of forming a film on a substrate placed in a processing container while heating the inside of the processing container with a heater may be performed (see, for example, Patent Documents 1 to 3).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object of the present disclosure is to provide a technique capable of suppressing deformation of a heating element.

Means for Solving the Problems

[0005] According to one aspect of the present disclosure, a ceiling heater provided above a reaction tube, a disk-shaped base material, a heating element continuously spread on the base material over a plurality of regions obtained by dividing a circle centered on the center of the base material into a fan shape, and each heating element spread in the plurality of regions is connected to the heating element in an adjacent region at a predetermined location, The base material has grooves corresponding to the shape of the heating element, and a wall is formed by a portion other than the portion where the grooves are provided. The distance between the heating elements laid flat in two adjacent regions is configured to be wider than the width of the wall separating the two regions. A ceiling heater is used. A technique is provided.

Advantages of the Invention

[0006] According to the present disclosure, deformation of the heating element can be suppressed.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Embodiments for Carrying Out the Invention

[0008] (1) Configuration of Substrate Processing Apparatus Hereinafter, embodiments will be described with reference to the drawings. However, in the following description, the same reference numerals may be assigned to the same components, and repeated descriptions may be omitted. Note that, for the sake of clarity of explanation, the drawings may schematically represent the width, thickness, shape, etc. of each part compared to the actual aspect, but this is merely an example and does not limit the interpretation of the present disclosure.

[0009] As shown in FIG. 1, the substrate processing apparatus 10 includes a cylindrical heating device 12, a cylindrical reaction tube 16 accommodated in the heating device 12 with a furnace interior space 14 therein, and a boat 20 as a substrate holder for holding a substrate 18 to be processed in the reaction tube 16. The boat 20 can load a plurality of substrates 18 in multiple stages with a gap in a horizontal state, and hold the plurality of substrates 18 in the reaction tube 16 in this state. The boat 20 is placed on an elevator (not shown) via a cap 22 and can be moved up and down by this elevator. Therefore, the loading of the substrate 18 into the reaction tube 16 and the removal of the substrate 18 from the reaction tube 16 are performed by the operation of the elevator.

[0010] Further, the reaction tube 16 forms a processing chamber 24 for accommodating the substrate 18. A gas introduction tube 26 is communicated in the reaction tube 16, and gas pipes 61a, 61b, 61c are connected to the gas introduction tube 26. Mass flow controllers (MFCs) 62a, 62b, 62c as flow controllers and valves 64a, 64b, 64c as on-off valves are installed in the gas pipes 61a, 61b, 61c in order from the upstream. Also, a gas exhaust pipe 56 is communicated in the reaction tube 16 to exhaust the inside of the processing chamber 24. A pressure sensor 68, an APC valve 66 as a pressure adjustment device, and a vacuum pump 65 as a vacuum device are installed in the gas exhaust pipe 56 in order from the upstream side.

[0011] The heating device 12 has a cylindrical shape and further includes a side heater 30 which is a side heating part for heating the furnace inner space 14 from the side, as a side heating part inside a heat insulation structure body having a structure in which a plurality of heat insulators are laminated, and a ceiling heater 31 which is an upper heating part for heating the furnace inner space 14 from above. The ceiling heater 31 is disposed below the upper wall portion 33 of the heat insulation structure body and above the reaction tube 16. The side heater 30 is divided into a plurality of parts in the substrate loading direction, for example, divided into four zones 30-1 to 30-4 from above. The side heater 30 is configured such that the heating temperature can be individually controlled in each of the divided zones. Details of the ceiling heater 31 will be described later.

[0012] The heat insulation structure body has a side wall portion 32 as a heat insulation part formed in a cylindrical shape and an upper wall portion 33 as a heat insulation part formed so as to cover the upper end of the side wall portion 32. The side wall portion 32 is formed in a multi-layer structure and is composed of a side wall outer layer 32a formed on the outer side of the plurality of layers of the side wall portion 32 and a side wall inner layer 32b formed on the inner side of the plurality of layers. A cooling gas passage 34 which is a cylindrical space is formed between the side wall outer layer 32a and the side wall inner layer 32b. And the side heater 30 is provided inside the side wall inner layer 32b, and the inside of the side heater 30 is a heat generation region. It goes without saying that the side wall portion 32 has a structure in which a plurality of heat insulators are laminated, but is not limited to such a structure.

[0013] A cooling gas supply port 36 is formed in the upper part of the side wall outer layer 32a. Further, a rapid cooling gas discharge port 42 communicating with the furnace inner space 14 is formed in the upper wall portion 33. Further, a cooling gas discharge port 43 is formed in the lower part of the side wall outer layer 32a. The rapid cooling gas discharge port 42 and the cooling gas discharge port 43 are respectively connected to exhaust pipes 45a, 45b and merged in a duct 50. A radiator 52 and an exhaust fan 54 are connected to the duct 50 from the upstream side, and the heated cooling gas in the heating device 12 is discharged to the outside of the device through the duct 50, the radiator 52 and the exhaust fan 54.

[0014] Here, a valve 39a that can be opened and closed is provided near the cooling gas supply port 36 and the duct 38a. Also, a valve 39b that can be opened and closed is provided near the rapid cooling gas discharge port 42 and the duct 50. Further, a valve 39c that can be opened and closed is provided near the cooling gas discharge port 43 and the duct 38b. By arranging the valves 39b and 39c near the duct 50 or the duct 38b, the influence of convection from the duct at the discharge port during non-use can be reduced, and the temperature uniformity within the substrate around the duct can be improved.

[0015] Furthermore, the supply of the cooling gas is controlled by opening and closing the valve 39a and turning the exhaust fan 54 ON / OFF. The cooling gas passage 34 is closed and opened by opening and closing the valve 39b or the valve 39c and turning the exhaust fan 54 ON / OFF, and the cooling gas is discharged from the rapid cooling gas discharge port 42 or the cooling gas discharge port 43, respectively.

[0016] As shown in FIG. 2, in each zone 30-1, 30-2, 30-3, 30-4 of the side heater 30, first temperature sensors 27-1, 27-2, 27-3, 27-4 as temperature detectors are installed, respectively. Also, a second temperature sensor 28 is installed in the ceiling heater 31. Further, third temperature sensors 29-1, 29-2, 29-3, 29-4 are installed in the processing chamber 24. The third temperature sensors may be installed only when acquiring the profile at the time of device startup and may be removed from the inside of the processing chamber 24 during the film formation process.

[0017] Next, the configuration of the control device 60 will be described. As shown in FIG. 2, the control device 60 is configured to control each component of the semiconductor manufacturing apparatus as the substrate processing apparatus 10 based on the set values of temperature, pressure, and flow rate set from the control computer 82 by components such as the first temperature sensors 27-1, 27-2, 27-3, 27-4, the second temperature sensor 28, the third temperature sensors 29-1, 29-2, 29-3, 29-4, the MFCs 62a, 62b, 62c, the valves 64a, 64b, 64c, the APC valve 66, and the pressure sensor 68.

[0018] The temperature control device 74 controls the power supplied by each of the heater driving devices 76-1 to 76-4 to each of the zones 30-1 to 30-4 of the side heater 30 so that the temperatures measured by the first temperature sensors 27-1 to 27-4 respectively become the temperatures set by the control computer 82. Also, the temperature control device 74 controls the power supplied by the heater driving devices 76-1 and 76-5 to the zone 30-1 and the ceiling heater 31 respectively so that the temperatures measured by the first temperature sensor 27-1 and the second temperature sensor 28 become the temperatures set by the control computer 82, specifically, so that the temperature of the upper substrate becomes the desired temperature.

[0019] The flow rate control device 78 controls the MFCs 62a to 62c and the valves 64a to 64c respectively so that the value of the flow rate of the gas measured by the flow rate sensor becomes equal to the value of the gas flow rate set by the control computer 82, and controls the flow rate of the gas introduced into the reaction tube 16 in the processing chamber 24. The pressure control device 80 controls the APC valve 66 etc. so that the pressure inside the reaction tube 16 measured by the pressure sensor 68 becomes equal to the value of the pressure set by the control computer 82, and controls the pressure in the processing chamber 24.

[0020] (2) Substrate processing step Next, using a substrate processing apparatus as a semiconductor manufacturing apparatus, an outline of a substrate processing step, which is a step in a semiconductor device manufacturing process and a substrate processing method for processing a substrate, will be described with reference to FIG. 3. This substrate processing step is, for example, a step for manufacturing a semiconductor device. In the following description, the operations and processes of each part constituting the substrate processing apparatus are controlled by the control device 60.

[0021] Here, an example of forming a film on the substrate 18 by alternately supplying a first processing gas (raw material gas) and a second processing gas (reaction gas) to the substrate 18 will be described. Hereinafter, an example of forming a SiN (silicon nitride) film as a thin film on the substrate 18 using a Si raw material gas, which is a Si-containing raw material gas in a liquid state at room temperature, as the raw material gas and NH3 (ammonia) gas, which is an N-containing raw material gas, as the reaction gas will be described. Note that, for example, a predetermined film may be formed on the substrate 18 in advance, and a predetermined pattern may be formed on the substrate 18 or the predetermined film in advance.

[0022] (Substrate loading step S102) First, the substrate 18 is loaded into the boat 20, carried into the processing chamber 24, and the substrate loading step S102 is performed.

[0023] (Film formation step S104) Next, a film formation step S104 of forming a thin film on the surface of the substrate 18 is performed. The film formation step sequentially executes the following four steps. During steps 1 to 4, the substrate 18 is heated to a predetermined temperature by the side heater 30. Also, specifically, the upper part of the reaction tube 16 is heated to a predetermined set temperature by the ceiling heater 31, which will be described in detail later. The predetermined set temperature is appropriately set according to the raw material gas. [Step 1] In step 1, the Si raw material gas is supplied into the processing chamber 24. Specifically, it is as follows. First, both the valve 64a provided in the gas pipe 61a and the APC valve 66 provided in the gas exhaust pipe 56 are opened, and the Si raw material gas whose flow rate is adjusted by the MFC62a is passed through the gas introduction pipe 26 and supplied into the processing chamber 24 from the gas supply holes formed in the gas introduction pipe 26 while exhausting from the gas exhaust pipe 56. At this time, the pressure in the processing chamber 24 is maintained at a predetermined pressure. By supplying the Si raw material gas, a thin film containing silicon (Si) is formed on the surface of the substrate 18. [Step 2] In Step 2, valve 64a is closed to stop the supply of Si raw material gas into the processing chamber 24. The APC valve 66 of the gas exhaust pipe 56 remains open, and the processing chamber 24 is evacuated by the vacuum pump 65 to remove the residual gas from the processing chamber 24. Also, valve 64c provided in the gas pipe 61c is opened, and an inert gas such as N2 whose flow rate is adjusted by the MFC62c is supplied into the processing chamber 24 to purge the residual gas in the processing chamber 24. [Step 3] In Step 3, NH3 gas is supplied into the processing chamber 24. Both the valve 64b provided in the gas pipe 61b and the APC valve 66 provided in the gas exhaust pipe 56 are opened, and the NH3 gas whose flow rate is adjusted by the MFC62b is passed through the gas introduction pipe 26 and supplied from the gas supply holes formed in the gas introduction pipe 26 to the processing chamber 24 while exhausting from the gas exhaust pipe 56. Also, the pressure in the processing chamber 24 is adjusted to a predetermined pressure. By the supply of NH3 gas, the Si raw material gas reacts with the Si thin film formed on the surface of the substrate 18 and a SiN film is formed on the substrate 18. [Step 4] In Step 4, the inside of the processing chamber 24 is purged again with an inert gas. Valve 64b is closed to stop the supply of NH3 gas into the processing chamber 24. The APC valve 66 of the gas exhaust pipe 56 remains open, and the processing chamber 24 is evacuated by the vacuum pump 65 to remove the residual gas from the processing chamber 24. Also, valve 64c provided in the gas pipe 61c is opened, and an inert gas such as N2 whose flow rate is adjusted by the MFC62c is supplied into the processing chamber 24 to purge the residual gas in the processing chamber 24.

[0024] The above Steps 1 to 4 are taken as one cycle, and by repeating this cycle a plurality of times, a SiN film with a predetermined film thickness is formed on the substrate 18.

[0025] (Substrate unloading process S106) Next, the boat 20 on which the substrate 18 on which the SiN film is formed is placed is unloaded from the processing chamber 24.

[0026] According to this embodiment, the processing gas is supplied to the processing chamber 24 in a state heated by at least the side heater 30 and the ceiling heater 31. That is, while the cycles of steps 1 to 4 are repeated a plurality of times, at least the ceiling heater 31 continuously heats the upper part of the reaction tube 16 so as to maintain a predetermined set temperature.

[0027] (3) Configuration of the ceiling heater Next, the details of the ceiling heater 31 will be described with reference to FIGS. 4 to 10. Hereinafter, the ceiling heater 31 provided above the reaction tube 16 will be used for the description.

[0028] As shown in FIG. 4, the ceiling heater 31 is provided substantially horizontally above the reaction tube 16. The ceiling heater 31 is fixed in a suspended state by a support portion 101 provided on the upper wall portion 33 of the heating device 12. A power supply portion 103 provided on the upper wall portion 33 of the heating device 12 is connected to a substantially central portion of the ceiling heater 31. The outer diameter of the ceiling heater 31 is formed to be equal to or larger than the outer diameter of the substrate 18.

[0029] As shown in FIG. 5, the ceiling heater 31 includes a disk-shaped base material 98 having electrical insulation, a heating element 100 which is a heating wire, and a lid member 102 having electrical insulation. The heating element 100 is accommodated in a groove 98a formed in the base material 98. The base material 98 has no opening below the heating element 100, and can substantially support the entire bottom surface of the heating element 100 and keep it flat. With such a configuration, while allowing the movement of the heating element 100 in the groove 98a due to the thermal expansion of the heating element 100, even when the heating element 100 undergoes plastic deformation, it is possible to prevent the heating element 100 from sagging downward and coming into contact with the reaction tube 16.

[0030] As shown in FIG. 6, the heating element 100 meanders in a region divided into a plurality of fan shapes from the center outward, and each arc is formed concentrically. An end portion 104 of the heating element 100 located at the center of the ceiling heater 31 is a power supply end portion for connecting a power supply wire, and is connected to the power supply portion 103 respectively.

[0031] The heating element 100 is continuously spread over a plurality of regions obtained by dividing a virtual circle centered at the center of the base material 98 into fan shapes. Specifically, the heating element 100 is configured to be continuously spread over the base material 98 in a meandering manner within regions A1 to A8 obtained by dividing a circle A, which is a virtual circle centered at the center of the base material 98, into 8 fan shapes. The regions A1 to A8 are formed by equally dividing the circle A into 8 fan shapes. The heating element 100 extends in the circumferential direction within each of the regions A1 to A8 and is formed to meander by turning back at the circumferential ends of each region. The meandering patterns in the regions A1 to A2, the regions A3 to A4, the regions A5 to A6, and the regions A7 to A8 are the same except for the end portion 104 and are rotationally symmetric about the center of the circle A, which is a virtual circle. That is, the heating element 100 has rotational symmetry.

[0032] Specifically, starting from one of the end portions 104, the heating element 100 draws a semi-circle, then turns back radially outward, draws a semi-circle with a larger diameter than the semi-circle before the turn-back, and turns back radially outward again at the circumferential end of the region A1. Then, while repeating the process of drawing an arc with a central angle of 45 degrees or less and a larger diameter than the arc before the turn-back and turning back radially outward at the circumferential end of the region A1, the heating element 100 is formed concentrically while meandering radially outward within the region A1.

[0033] When the heating element 100 is turned back so as to reach the outermost circumferential arc on the circumferential side of the circle A, it draws an arc with a central angle greater than 45 degrees and within 90 degrees and a larger diameter than the arc before the turn-back, and turns back radially inward at the circumferential end of the region A2 on the side opposite to the region A1. Then, while repeating the process of drawing an arc with a central angle of 45 degrees or less and a smaller diameter than the arc before the turn-back and turning back radially inward at the circumferential end of the region A2, the heating element 100 is formed concentrically while meandering radially inward within the region A2.

[0034] When the heating element 100 is folded so as to reach the arc on the central side of circle A, it draws an arc with a central angle greater than 45 degrees and within 90 degrees, having a smaller diameter than the arc before folding, and is folded radially outward at the circumferential end on the side opposite to region A2 in region A3. While repeating the process of drawing an arc with a central angle within 45 degrees, having a larger diameter than the arc before folding, and folding again at the circumferential end of region A3, it is formed concentrically while meandering radially outward within region A3.

[0035] When the heating element 100 is folded so as to reach the outermost arc on the circumferential side of circle A in region A3, it is formed concentrically while meandering radially inward within region A4 by repeating the process of folding at the circumferential end of region A4 radially inward in the same manner as the heating element 100 in region A2.

[0036] When the heating element 100 is folded so as to reach the arc on the central side of circle A in region A4, it is formed concentrically while meandering radially outward within region A5 by repeating the process of folding at the circumferential end of region A5 radially outward in the same manner as the heating element 100 in region A3.

[0037] When the heating element 100 is folded so as to reach the outermost arc on the circumferential side of circle A in region A5, it is formed concentrically while meandering radially inward within region A6 by repeating the process of folding at the circumferential end of region A6 radially inward in the same manner as the heating element 100 in region A2.

[0038] When the heating element 100 is folded so as to reach the arc on the central side of circle A in region A6, it is formed concentrically while meandering radially outward within region A7 by repeating the process of folding at the circumferential end of region A7 radially outward in the same manner as the heating element 100 in region A3.

[0039] Then, when the heating element 100 is folded back so as to reach the outermost arc on the circumferential side of the circle A in region A7, it is formed concentrically while meandering radially inward in region A8, repeating the process of folding back at the circumferential end of region A8 radially inward in the same manner as the heating element 100 in region A2. After being folded back inward to the central arc, it draws a concentric semicircle to the circumferential end on the region 5 side of region A6 parallel to the outer circle, and then folds back again in the inner diameter direction, drawing a concentric semicircle with a smaller diameter than the outer circle to the circumferential end on the region A1 side of region A8 to become the other end point of end portion 104.

[0040] In this way, the heating element 100 is formed so as to connect between the two end portions 104 in one stroke. Generally, the heating element 100 may have a constant cross-sectional area so that the current density is uniform. When the heating element 100 is formed from a plate-like material, it may have a substantially constant width. However, in order to improve the uniformity of the current density or the rising temperature or to extend the life, the cross-sectional area at the folding portion 100a or the like may be increased or decreased. The heating element 100 in the present embodiment is configured to have a plurality of folding portions 100a, which are folding locations, on the same circumference. Also, the folding positions of the respective folding portions 100a of the heating element 100 within each region coincide in the radial direction and are configured to be adjacent in the circumferential direction.

[0041] Further, the maximum angle of the central angle of the section where the heating element 100 is continuously formed in an arc shape is configured to be 90 degrees or less. Also, each heating element 100 laid out within each of the regions A1 to A8 is configured to be connected to the heating element 100 in an adjacent region at a predetermined location on the circumferential side or the central side of the circle A. Also, the heating element 100 is separated from the heating element 100 in an adjacent region by a predetermined interval.

[0042] Thus, the heating element 100 extends in the circumferential direction within each of the fan-shaped regions A1 to A8, and is configured to meander while repeatedly turning radially outward or inward at the circumferential ends within each of the regions A1 to A8, such that the respective arcs are formed concentrically. By configuring it to turn within a plurality of fan-shaped regions in this way, the amount and direction of displacement due to thermal expansion of the heating element become closer inside and outside the folding portion 100a, and deformation of the heating element 100 is suppressed.

[0043] In the heating element 100 formed with such a pattern, the elongation due to thermal expansion or plastic deformation is greatest in the outermost peripheral arc that connects between the respective regions on the circumference of circle A and has a length approximately twice the arc length in each region of circle A. The outermost peripheral arc should be allowed an elongation amount of approximately twice or more the elongation amount of the arc when arranged on the circumference of circle A within each region. Also, the allowable elongation amount at other locations of the heating element 100 is set to be smaller than or equal to the allowable elongation amount in the section of the arc one layer outside. The heating element 100 set in this way moves through the groove 98a due to elongation. In particular, with the elongation of the outermost peripheral arc, the heating elements 100 in the two regions connected by the outermost peripheral arc can move in a direction away from each other, but this movement converges within the two regions and does not spread to other regions. That is, the elongation of each outermost peripheral arc only affects locally, and since they are symmetric with respect to the center of circle A, displacement and deformation of the entire heating element 100 are suppressed.

[0044] As shown in FIG. 7, the base material 98 has a groove 98a corresponding to the shape of the heating element 100, and a wall 98b is formed by the portion other than the location where the groove 98a is provided. Also, the back surface (lower surface) of the surface of the base material 98 where the groove 98a is formed and on the side where the reaction tube 16 is installed is formed in a flat plate shape. Further, the base material 98 has a transparent or opaque interior and is composed of, for example, synthetic quartz, alumina, etc., and the inner surface of the groove 98a is roughened.

[0045] As shown in Fig. 8, the lid member 102 has eight arms 102a extending radially from the center. The lid member 102 is made of, for example, synthetic quartz.

[0046] Then, as shown in Fig. 9, the heating element 100 is housed and spread in the groove 98a of the base material 98, and the lid member 102 is mounted thereon. That is, the heating element 100 is simply placed on the bottom of the groove 98a. Then, the base material 98 and the lid member 102 are fixed by screwing on the outer peripheral side of the heating element 100. At this time, each arm 102a is arranged along the boundary of the adjacent regions between the heating elements 100 in the adjacent regions and between the folded portions 100a. That is, the folded portions 100a of the adjacent regions are sandwiched and held between the base material 98 and the lid member 102 (arm 102a). That is, at least a part above the base material 98 and the heating element 100 is open. Thereby, it is possible to prevent the folded portion 100a from protruding from the groove 98a and contacting the heating elements 100 in the adjacent regions, and the lid member 102 can be configured to be lightweight.

[0047] Here, as shown in Fig. 10, the distance D1 between the folded portions 100a of the adjacent regions is configured to be wider than the width D2 of the wall 98b separating the two regions. That is, it is set so that D1 > D2. Also, the distance D3 between the wall 98b separating the regions and the folded portion 100a of the outermost circumferential heating element 100 is configured to be longer than the elongation amount due to the plastic deformation of the outermost circumferential heating element 100. This elongation amount is obtained empirically as that occurring in normal use during the assumed service life. Also, the distance between the side portion of the heating element 100 spread so as to extend in the circumferential direction within each region and the wall 98b is configured such that the distance D5 between the side portion of the heating element 100 on the circumferential side of circle A and the wall 98b is longer than the distance D4 between the side portion of the heating element 100 on the center side of circle A and the wall 98b in the non-heated state. That is, it is set so that D4 < D5. Thereby, a space is ensured such that the heating element does not hit the wall 98b constituting the base material 98 even when the heating element expands due to repeated heating and cooling.

[0048] Here, when the substrate 18 placed on the upper part of the boat 20 is heated only by the side heater 30 (when the ceiling heater 31 is OFF), the peripheral part of the substrate 18 is actively heated, and due to the heat dissipation effect in the central part of the substrate 18, especially the heating in the central part is insufficient. As a result, variations occur in the in-plane temperature distribution, and the in-plane temperature uniformity may deteriorate. That is, when the substrate 18 is heated only by the side heater 30, the in-plane temperature distribution of the substrate 18 placed on the upper part of the boat 20 may be a concave distribution with a lower temperature in the central part.

[0049] Also, an iron-based alloy can be used as the material of the heating element. However, such a heating element is plastically deformed (elongated) by repeating temperature rise and fall. This plastic deformation is considered to be caused by annealing while at least a part of the cross-section of the heating element is subjected to tensile stress during the temperature drop process, and the elongation amount accumulates according to the number of times of repeating temperature rise and fall. Note that while the number of repetitions is small, it may not elongate or may even contract. Since elongation can occur without an external force, it is difficult to completely suppress it. Therefore, when the heating element that has elongated to the limit that can be accommodated in the base material thermally expands in a state of being partially constrained on the base material, buckling may occur where the unconstrained part of the heating element pops out from the base material. This buckling is also plastic deformation and deteriorates as the elongation progresses. That is, it was an issue to improve the durability of the ceiling heater.

[0050] According to the present disclosure, in a plurality of fan-shaped regions, they are formed so as to be folded back at the circumferential direction ends respectively, and the arc length on the same circumference is shortened. As a result, the elongation amount per arc becomes small, deformation of the heating element is suppressed, and it is possible to suppress the heating element from popping out of the groove formed in the base material.

[0051] Also, by providing the ceiling heater 31 above the reaction tube 16, it is possible to stabilize the temperature above the reaction tube 16 and improve the uniformity of the film formation film thickness.

[0052] That is, it is possible to prevent unfavorable deformations such as the lifting of the heating element due to plastic deformation, suppress contact, short circuit, and disconnection of the heating element, and achieve a longer service life of the ceiling heater 31.

[0053] (4) Modified Example The ceiling heater 31 in the above-described embodiment can be modified as shown in the following modified examples. Unless otherwise specified, the configuration in the modified example is the same as the configuration in the above-described embodiment, and the description thereof will be omitted.

[0054] (Modified Example) The modified example of the above-described ceiling heater 31 will be described with reference to FIG. 11. The ceiling heater 110 in the modified example is different in shape from the above-described ceiling heater 31, the heating element, and the base material that houses the heating element. In FIG. 11, the lid member 102 is shown by a dashed line to make the shapes of the heating element and the base material easier to understand.

[0055] In the ceiling heater 110, the heating element 100 is configured to be divided into two parts. That is, two heating elements, a first heating element 100-1 and a second heating element 100-2, are used as the heating element 100. The base material 112 has grooves 112a corresponding to the shapes of the first heating element 100-1 and the second heating element 100-2, and a wall 112b is formed by a portion other than the portion where the grooves 112a are provided. The first heating element 100-1 and the second heating element 100-2 are configured to be respectively housed in the grooves 112a. The first heating element 100-1 and the second heating element 100-2 are formed to extend in the circumferential direction within the fan-shaped regions A1 to A8 and to be laid out so as to fold back and meander at the circumferential ends of each region.

[0056] The first heating element 100-1 starts from the center of the center of the base material 112 at the end 104. Similar to the above-described ceiling heater 31, within the regions A1 to A8, it extends in the circumferential direction and repeatedly folds back at the circumferential ends of each region, and is laid out to about half of the radius of the base material 112 within each region, and the end 104 of the other end is arranged at the center of the center of the base material 112.

[0057] The second heating element 100-2 extends circumferentially within any region on the outer peripheral side of the first heating element 100-1, starting from the end 104a, within regions A1 to A8. While repeatedly folding back at the circumferential ends of each region, it is spread to the outer peripheral side of the base material within each region, and the end point of the other end 104a is arranged at a position facing the end 104a. At this time, the two ends 104a are partitioned by the wall 112b, the two ends 104a are at positions not adjacent to the folded-back portion 100a, and are arranged on the inner peripheral side of the second heating element 100-2.

[0058] At this time, the second temperature sensor 28 is configured to be able to measure the temperatures of both the first heating element 100-1 and the second heating element 100-2. The temperature sensor 28 independently measures the temperature of the first heating element 100-1 and the temperature of the second heating element 100-2, and the heater driving device 76-5 is configured to be able to independently control the first heating element 100-1 and the second heating element 100-2.

[0059] With such a configuration, in addition to the effects of the ceiling heater 31 in the above-described embodiment, since the applied power can be made different between the first heating element 100-1 and the second heating element 100-2, the heat generation amounts of the first heating element 100-1 and the second heating element 100-2 can be made different. Thereby, the temperature distribution of the ceiling heater can be made into a convex distribution or a concave distribution. For example, by making the amount of electric power applied to the second heating element 100-2 at least larger than the amount of electric power applied to the first heating element 100-1, the temperature distribution of the ceiling heater can be made into a concave distribution.

[0060] Also, since the applied power can be made different between the first heating element 100-1 and the second heating element 100-2, the temperature distribution of the ceiling heater during temperature rise can be made into a convex distribution. Thereby, by turning on the ceiling heater from the temperature rising stage of the substrate, the temperature controllability of the upper substrate can be improved, and the surface-to-surface temperature uniformity of the upper substrate can be improved. Thereby, the temperature stabilization time of the substrate can be shortened, and the productivity can be improved.

[0061] The embodiments and modifications of the present disclosure have been specifically described above. However, the present disclosure is not limited to the above-described embodiments and modifications, and various changes can be made without departing from the gist thereof.

[0062] For example, in the above-described embodiments and modifications, the case of using one or two heating elements has been described as an example. However, the present disclosure is not limited thereto, and it can also be preferably applied to the case of using three or more heating elements.

[0063] Also, in the above-described embodiments and modifications, the case where the heating element 100 is laid out in a meandering manner within each of the eight fan-shaped divided regions has been described. However, the present disclosure is not limited thereto, and it may be meandering within each of the regions divided into a plurality of fan shapes, and it can also be preferably applied to the case where it is laid out in a meandering manner within each of the regions divided into eight or more fan shapes.

[0064] Also, in the above-described embodiment, an example of the step of forming a SiN film on the substrate 18 has been described. However, the present disclosure is not limited thereto, and it can be preferably applied when forming, modifying, or etching a film using the ceiling heater 31.

[0065] It is applied to a vertical processing apparatus for collectively processing a plurality of objects to be processed.

Explanation of Reference Numerals

[0066] 10 Substrate processing apparatus 18 Substrate 30 Side heater 31 Ceiling heater 98 Base material 100 Heating element 102 Cover member

Claims

1. A ceiling heater provided above a reaction tube, comprising: a disc-shaped base material; a heating element spread continuously over a plurality of regions formed by dividing a circle centered at the center of the base material into fan shapes; each of the heating elements spread in the plurality of regions is connected to the heating element in an adjacent region at a predetermined location; the base material has grooves corresponding to the shape of the heating element, and walls are formed by portions other than the portions where the grooves are provided, and the distance between the heating elements spread in two adjacent regions is configured to be wider than the width of the wall separating the two regions; a ceiling heater.

2. The ceiling heater according to claim 1, wherein each of the heating elements extends in the circumferential direction within each region and is spread so as to fold back and meander at the circumferential end of the region.

3. The ceiling heater according to claim 1, wherein the heating element is connected to the heating element in an adjacent region on the circumferential side or the center side of the circle.

4. The ceiling heater according to claim 1, wherein the distance between the wall separating the regions and the outermost circumferential heating element is configured to be longer than the elongation amount due to plastic deformation of the outermost circumferential heating element.

5. The ceiling heater according to claim 3, wherein the distance between the wall separating the regions and the outermost circumferential heating element is configured to be longer than the elongation amount due to plastic deformation of the outermost circumferential heating element.

6. The ceiling heater according to claim 1, wherein at least a part above the base material or the heating element is open.

7. further comprising a lid member having an arm portion extending radially along the boundary of the plurality of regions, The ceiling heater according to claim 1, wherein a folding portion, which is a portion where the heating element folds back, is held between the base material and the lid member.

8. The ceiling heater according to claim 1, wherein the plurality of regions are formed by dividing a circle centered at the center of the base material into 8 or more fan shapes.

9. The ceiling heater according to claim 1, wherein the maximum angle of the central angle of the section where the heating element is continuously formed in an arc shape is 90 degrees or less.

10. The ceiling heater according to claim 2, wherein the distance between the side portion of the heating element spread so as to extend in the circumferential direction within the region and the wall of the base material is configured to be longer on the circumferential side than on the center side of the circle.

11. The ceiling heater according to claim 1, wherein the base material contains transparent quartz.

12. The ceiling heater according to claim 1, wherein the groove has a roughened bottom.

13. The ceiling heater according to claim 1, wherein the base material is configured to be able to substantially support the entire bottom surface of the heating element.

14. The ceiling heater according to claim 7, wherein the base material and the lid member have electrical insulation properties.

15. The ceiling heater according to claim 2, wherein the heating element has rotational symmetry.

16. The ceiling heater according to claim 3, wherein the heating element has rotational symmetry.

17. A ceiling heater provided above a reaction tube, comprising a disc-shaped base material and a heating element continuously spread on the base material over a plurality of regions obtained by dividing a circle centered on the center of the base material into fan-shaped regions. Each of the heating elements spread in the plurality of regions is connected to the heating element in an adjacent region at a predetermined location. The base material has a groove corresponding to the shape of the heating element, and a wall is formed by a portion other than the portion where the groove is provided. The interval between the heating elements spread in two adjacent regions is configured to be wider than the width of the wall separating the two regions. A step of controlling the heating amount of the ceiling heater to heat a substrate in the reaction tube; A step of supplying a processing gas to the substrate to process the substrate; A method for manufacturing a semiconductor device comprising the above steps.

18. A ceiling heater provided above a reaction tube, comprising a disc-shaped base material and a heating element continuously spread on the base material over a plurality of regions obtained by dividing a circle centered on the center of the base material into fan-shaped regions. Each of the heating elements spread in the plurality of regions is connected to the heating element in an adjacent region at a predetermined location. The base material has a groove corresponding to the shape of the heating element, and a wall is formed by a portion other than the portion where the groove is provided. The interval between the heating elements spread in two adjacent regions is configured to be wider than the width of the wall separating the two regions. A step of controlling the ceiling heater to heat a substrate in the reaction tube; A step of supplying a processing gas to the substrate to process the substrate; A substrate processing method comprising the above steps.

19. A reaction tube A ceiling heater comprising: a disc-shaped base material provided above the reaction tube; and a heating element spread continuously on the base material over a plurality of regions obtained by dividing a circle centered on the center of the base material into fan-shaped regions, wherein each of the heating elements spread in the plurality of regions is connected to the heating element of an adjacent region at a predetermined location, the base material has grooves corresponding to the shape of the heating element, a wall is formed by a portion other than the portion where the grooves are provided, and the interval between the heating elements spread in two adjacent regions is configured to be wider than the width of the wall separating the two regions. A substrate processing apparatus comprising the same.

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