Substrate processing apparatus, substrate heating method, and method for producing semiconductor device

Abstract

Provided is a technique for heating a substrate so as to equalize the temperature of the substrate.　The present invention comprises a heat insulator including a heat storage material disposed in the vicinity of a substrate accommodated in a reaction container configured to be heated to a predetermined temperature, wherein the heat storage material is configured such that, when the melting point of the heat storage material is higher than the predetermined temperature, the heat storage material is solid, and when the melting point of the heat storage material is lower than the predetermined temperature, the heat storage material is liquid.

Description

Substrate processing apparatus, substrate heating method, and method of manufacturing a semiconductor device

[0001] The present disclosure relates to a substrate processing apparatus, a substrate heating method, and a method of manufacturing a semiconductor device.

[0002] As one step of a semiconductor device manufacturing process, a process of forming a film on a substrate may be performed (see, for example, Patent Document 1). Patent Document 1 describes a technique for improving the temperature uniformity of a substrate disposed near a furnace mouth portion. However, it is difficult to heat these substrates so that their temperatures become equal, and further improvement is required.

[0003] Japanese Patent Application Laid-Open No. 2019-021910

[0004] The present disclosure provides a technique for heating so as to equalize the temperature of a substrate.

[0005] According to one aspect of the present disclosure, there is provided a heat insulator including a heat storage material disposed near a substrate accommodated in a reaction vessel configured to be heated to a predetermined temperature, wherein if the melting point of the heat storage material is higher than the predetermined temperature, the heat storage material is solid, and if the melting point of the heat storage material is lower than the predetermined temperature, the heat storage material is liquid.

[0006] According to the present disclosure, it is possible to heat so as to equalize the temperature of a substrate.

[0007] Figure 1 is a longitudinal cross-sectional view showing a schematic of a vertical processing furnace of a substrate processing apparatus in one aspect of the present disclosure. Figure 2 is a diagram illustrating the functional configuration of a controller of a substrate processing apparatus in one aspect of the present disclosure. Figure 3 is a cross-sectional view showing the structure of an insulating body in one aspect of the present disclosure. Figure 4 is a diagram showing the properties of the heat storage material shown in Figure 3. Figure 5 is a diagram comparing the properties of a phase-change heat storage material and a sensible heat storage material. Figure 6(a) is a diagram showing a first example of the arrangement of insulating bodies in a boat, illustrating the image of heat storage from heating by a heater when the furnace temperature is higher than the temperature of the insulating body. Figure 6(b) is a diagram showing the image of heating the wafer by heat dissipation from the insulating body when the furnace temperature is lower than the temperature of the insulating body in the arrangement of insulating bodies shown in Figure 6(a). Figure 6(c) is a diagram showing a second example of the arrangement of insulating bodies in a boat. Figure 6(d) is a diagram showing an example of further arrangement of reflectors in the arrangement of insulating bodies shown in Figure 6(a). Figure 6(e) is a diagram showing a third example of the arrangement of insulating bodies in a boat. Figure 7 is a diagram illustrating heat storage and heat dissipation using overshoot. Figure 8 illustrates the RDD assistance provided by heat storage and heat dissipation.

[0008] Hereinafter, one aspect of this disclosure will be described, mainly with reference to Figures 1 to 8. Note that the drawings used in the following description are all schematic, and the dimensional relationships and ratios of the elements shown in the drawings do not necessarily correspond to reality. Furthermore, the dimensional relationships and ratios of the elements do not necessarily correspond between multiple drawings. Also, substantially identical elements are denoted by the same reference numerals across multiple drawings, and each element is described in the drawing in which it first appears; in subsequent drawings, the description is omitted unless specifically required. Unless otherwise specified in the specification, each element is not limited to one, and there may be multiple elements.

[0009] (1) Configuration of the substrate processing apparatus A substrate processing apparatus 1 in one embodiment of the present disclosure will be described with reference to Figure 1. Figure 1 shows a schematic diagram in which a heating pipe 100 is provided in the exhaust pipe 231. In this embodiment, the heating pipe 100 is not necessary, and the heating pipe 100 is used in other embodiments.

[0010] (Processing Furnace) As shown in Figure 1, a reaction tube 203 is provided inside the heater 207, which is a heating means (heating section), as a processing vessel (reaction vessel) for processing the wafer 200, which is a substrate. The lower end opening of this reaction tube 203 is airtightly closed by a seal cap 219, which is a lid, via an O-ring 220, which is an airtight member. At least the heater 207, reaction tube 203, manifold 209 as a furnace opening, and seal cap 219 form a processing furnace 202. At least the reaction tube 203, manifold 209, and seal cap 219 form a processing chamber 201. A boat 217, which is a holder, is installed on the seal cap 219 via a quartz cap 218 and inserted into the processing chamber 201. Multiple wafers 200 to be batch processed are stacked horizontally in multiple layers on the boat 217. The heater 207 heats the wafers 200 inserted into the processing chamber 201 to a predetermined temperature.

[0011] The supply piping 10 is connected to a gas supply source 4 that supplies a first processing gas as a processing gas, a flow controller (mass flow controller: MFC) 41 for controlling the flow rate, a valve 34 which is an on / off valve, and a nozzle 234, from the upstream side of the gas flow. The first processing gas is supplied into the processing chamber 201 via the nozzle 234. The supply piping 10, MFC 41, valve 34, and nozzle 234 constitute the first processing gas supply system. The gas supply source 4 may also be included in the first processing gas supply system. The first processing gas supply system can also be referred to as the gas supply system.

[0012] The supply piping 11 is connected to a gas supply source 5, an MFC 32, a valve 35, and a nozzle 233, which supply a second processing gas as a processing gas from the upstream side of the gas flow. The second processing gas is supplied into the processing chamber 201 via the nozzle 233. The supply piping 11, MFC 32, valve 35, and nozzle 233 constitute the second processing gas supply system. The gas supply source 5 may also be included in the second processing gas supply system. The second processing gas supply system can also be referred to as the gas supply system.

[0013] A supply pipe 40 for supplying inert gas is connected downstream of valve 34 in supply pipe 10. A valve 39 is provided in supply pipe 40. Also, a supply pipe 6 for supplying inert gas is connected downstream of valve 35 in supply pipe 11. A valve 36 is provided in supply pipe 6.

[0014] An exhaust pipe 231, which is an exhaust pipe for exhausting gas, is connected to the processing chamber 201. A pressure sensor 245, an APC valve 243, and a vacuum pump 246 are connected to the exhaust pipe 231 from the upstream side of the gas flow. The exhaust pipe 231, pressure sensor 245, and APC valve 243 constitute the gas exhaust system. The vacuum pump 246 may also be included in the gas exhaust system. The gas exhaust system can also be referred to as the exhaust system.

[0015] A nozzle 234 is installed along the wafer 200 stacking direction from the bottom to the top of the reaction tube 203. The nozzle 234 is provided with multiple gas supply holes for supplying gas. These gas supply holes are opened at intermediate positions between adjacent wafers 200, and gas is supplied to the surface of the wafers 200. A nozzle 233 is similarly installed along the wafer 200 stacking direction, approximately 120° around the inner circumference of the reaction tube 203 from the position of nozzle 234. This nozzle 233 is also similarly provided with multiple gas supply holes. Nozzle 234 supplies a first processing gas from supply pipe 10 and an inert gas from supply pipe 40 into the processing chamber 201. Nozzle 233 supplies a second processing gas from supply pipe 11 and an inert gas from supply pipe 6 into the processing chamber 201. The processing gas is supplied alternately from nozzles 234 and 233 into the processing chamber 201 to perform film formation.

[0016] The reaction tube 203 is equipped with boats 217 on which multiple wafers 200 are placed in multiple stages at equal intervals. These boats 217 can move in and out of the reaction tube 203 by a boat elevator (not shown). In addition, a rotating mechanism 267 is provided to rotate the boats 217 in order to improve the uniformity of the processing. By rotating the rotating mechanism 267, the boats 217, which are held in place by the quartz cap 218, are rotated.

[0017] (Control Unit) The controller 321, which serves as the control unit (control means), will be explained using Figure 2. The controller 321 is configured as a computer equipped with a CPU (Central Processing Unit) 321a, RAM (Random Access Memory) 321b, storage device 321c, and I / O port 321d. The RAM 321b, storage device 321c, and I / O port 321d are configured to exchange data with the CPU 321a via an internal bus 321e. An input / output device 322, configured as, for example, a touch panel, is connected to the controller 321.

[0018] The storage device 321c is composed of, for example, flash memory, an HDD (Hard Disk Drive), etc. The storage device 321c contains, in a readable format, control programs for controlling the operation of the substrate processing device 1, and process recipes that describe the procedures and conditions for the substrate processing described later. The process recipe is a combination of elements that allows the controller 321 to execute each step in the substrate processing process described later and obtain predetermined results. The RAM 321b is configured as a memory area (work area) where programs and data read by the CPU 321a are temporarily held.

[0019] The I / O port 321d is connected to the MFCs 32, 33, 41, valves 34, 35, 36, 39, pressure sensor 245, APC valve 243, vacuum pump 246, heater 207, temperature sensor 263, rotating mechanism 267, and the pipe heating system 400 described later. In this embodiment, the pipe heating system 400 is not required and is used in other embodiments.

[0020] The CPU 321a is configured to read and execute a control program from the storage device 321c, and to read a process recipe from the storage device 321c in response to input of operation commands from the input / output device 322. The CPU 321a is configured to control the flow rate adjustment operations of various gases by the MFCs 32, 33, and 41, the opening and closing operations of valves 34, 35, 36, and 39, the opening and closing operations of the APC valve 243 and the pressure adjustment operations based on the pressure sensor 245 by the APC valve 243, the temperature adjustment operations of the heater 207 based on the temperature sensor 263, the starting and stopping of the vacuum pump 246, the rotation and rotation speed adjustment operations of the boat 217 by the rotating mechanism 267, and the temperature adjustment operations in the piping heating system 400, etc., in accordance with the contents of the read process recipe.

[0021] The controller 321 can be configured by installing the above-mentioned program, stored in an external storage device (for example, a semiconductor memory such as a USB memory or memory card) 323, onto a computer. The storage device 321c and the external storage device 323 are configured as computer-readable recording media. Hereinafter, these will be collectively referred to simply as recording media. In this specification, the term recording media may include only the storage device 321c, only the external storage device 323, or both. The program may also be provided to the computer using communication means such as the Internet or a dedicated line, without using the external storage device 323.

[0022] (2) Substrate Processing Process Next, an example sequence of a process for forming a film on a substrate (hereinafter also referred to as film formation process) as one step in the manufacturing process of a semiconductor device (device), using the substrate processing apparatus 1 described above, will be explained. Here, an example of forming a film on a wafer 200 by alternately supplying a first processing gas and a second processing gas to the wafer 200 will be explained. In the following explanation, the operation of each part constituting the substrate processing apparatus 1 is controlled by the controller 321.

[0023] In this specification, the term "wafer" may refer to the wafer itself or to a laminate of a wafer and a predetermined layer or film formed on its surface. In this specification, the term "surface of the wafer" may refer to the surface of the wafer itself or to the surface of a predetermined layer formed on the wafer. In this specification, when it is stated that "a predetermined layer is formed on the wafer," it may mean that the predetermined layer is formed directly on the surface of the wafer itself or that the predetermined layer is formed on a layer already formed on the wafer. In this specification, the term "substrate" has the same meaning as when it is used with the term "wafer."

[0024] (Wafer Charging and Boat Loading) Once multiple wafers 200 are loaded into the boat 217, the boat 217 is moved into the processing chamber 201 by a boat elevator (not shown). At this time, the seal cap 219 hermetically seals the lower end of the reaction tube 203 via the O-ring 220.

[0025] (Pressure and Temperature Adjustment) The processing chamber 201, i.e., the space where the wafer 200 is located, is evacuated (reduced pressure exhaust) by the vacuum pump 246 so that it reaches a predetermined pressure (vacuum level). At this time, the pressure inside the processing chamber 201 is measured by the pressure sensor 245, and the APC valve 243 is feedback controlled based on this measured pressure information. The vacuum pump 246 is kept running continuously at least until the processing of the wafer 200 is completed.

[0026] Furthermore, the wafer 200 inside the processing chamber 201 is heated by the heater 207 so that it reaches a predetermined temperature. At this time, the amount of power supplied to the heater 207 is feedback-controlled based on the temperature information detected by the temperature sensor 263 so that the processing chamber 201 has a predetermined temperature distribution. Heating of the processing chamber 201 by the heater 207 is continued at least until the processing of the wafer 200 is completed.

[0027] Furthermore, the rotation mechanism 267 initiates the rotation of the boat 217 and the wafer 200. The rotation of the boat 217 by the rotation mechanism 267 causes the wafer 200 to rotate. The rotation of the boat 217 and the wafer 200 by the rotation mechanism 267 continues at least until the processing of the wafer 200 is completed.

[0028] (Substrate Processing) Once the temperature inside the processing chamber 201 stabilizes at a preset processing temperature, the following two steps, namely the first and second steps, are executed sequentially. In this specification, processing temperature refers to the temperature of the wafer 200 or the temperature inside the processing chamber 201, and processing pressure refers to the pressure inside the processing chamber 201. Processing time refers to the time during which the processing is continued. These terms are also used in the following description.

[0029] [First Step] In the first step, valve 34 is opened, and the first processing gas is flowed from the gas supply source 4 into the supply piping 10. The flow rate of the first processing gas is adjusted by the MFC 41, and it is supplied into the processing chamber 201 via valve 34 and nozzle 234, and exhausted from the exhaust piping 231. At this time, the first processing gas is supplied to the wafer 200. At the same time, valve 39 is opened, and an inert gas is flowed into the supply piping 10 via supply piping 40. The inert gas is supplied into the processing chamber 201 together with the first processing gas and exhausted from the exhaust piping 231. By supplying the first processing gas to the wafer 200, a first layer is formed on the outermost surface of the wafer 200.

[0030] After the first layer is formed, valve 34 is closed and the supply of the first processing gas is stopped. At this time, APC valve 243 is left open and vacuum pump 246 evacuates the processing chamber 201, discharging any unreacted or remaining first processing gas that has contributed to the formation of the first layer from the processing chamber 201. At this time, valve 39 is left open and the supply of inert gas to the processing chamber 201 is maintained. The inert gas acts as a purge gas, thereby enhancing the effect of discharging any remaining gas from the processing chamber 201.

[0031] [Second Step] After the first step is completed, a second processing gas is supplied to the wafer 200 in the processing chamber 201, that is, to the first layer formed on the wafer 200. The second processing gas is activated by heat and supplied to the wafer 200.

[0032] In the second step, the opening and closing of valves 35 and 36 is controlled in the same manner as the opening and closing of valves 34 and 39 in the first step. Specifically, valve 35 is opened, and the second processing gas is allowed to flow from the gas supply source 5 into the supply piping 11. The flow rate of the second processing gas is adjusted by the MFC 32, and it is supplied into the processing chamber 201 via valve 35 and nozzle 233, and exhausted through exhaust piping 231. At this time, the second processing gas is supplied to the wafer 200. Simultaneously, valve 36 is opened, and an inert gas is allowed to flow into the supply piping 11 via supply piping 6. The inert gas is supplied into the processing chamber 201 together with the second processing gas and exhausted through exhaust piping 231. The second processing gas supplied to the wafer 200 reacts with at least a portion of the first layer formed on the wafer 200 in the first step. As a result, the first layer is transformed (modified) into the second layer.

[0033] After the second layer is formed, the valve 35 is closed and the supply of the second process gas is stopped. Then, using the same processing procedure as in the first step, any unreacted or second process gas and reaction by-products remaining in the processing chamber 201 that have contributed to the formation of the second layer are discharged from the processing chamber 201.

[0034] (Performed a predetermined number of times) By performing the above two steps non-simultaneously, that is, without synchronization, a predetermined number of cycles (n times, where n is an integer of 1 or more) can be performed to form a film of a predetermined thickness on the wafer 200.

[0035] (Purge and return to atmospheric pressure) After the substrate processing is complete, valves 36 and 39 are opened, and inert gas is supplied into the processing chamber 201 from supply pipes 11 and 10 via supply pipes 6 and 40, and exhausted from exhaust pipe 231. The inert gas acts as a purge gas. This purges the processing chamber 201, removing any remaining gases and reaction by-products from the processing chamber 201 (purging). Subsequently, the atmosphere inside the processing chamber 201 is replaced with inert gas (inert gas replacement), and the pressure inside the processing chamber 201 is returned to normal pressure (return to atmospheric pressure).

[0036] (Boat Unloading and Wafer Discharge) The seal cap 219 is lowered by the boat elevator, opening the lower end of the reaction tube 203. The processed wafer 200, supported by the boat 217, is then discharged from the lower end of the reaction tube 203 to the outside of the reaction tube 203. The processed wafer 200 is removed from the boat 217.

[0037] (3) Configuration of the Insulator The insulator 300 is placed near the wafers 200 housed in a reaction tube 203 configured to be heated to a predetermined temperature. For example, the insulator 300 is placed near a plurality of wafers 200 held in a boat 217. As shown in Figure 3, the insulator 300 includes a heat storage material 301. Specifically, the insulator 300 is configured to seal the heat storage material 301 with a quartz member 302. The quartz member 302 is composed of two quartz substrates, and the two quartz substrates are, for example, high-temperature diffusion bonded. In other words, the heat storage material 301 is sealed between the two quartz substrates. By sealing the heat storage material 301 with the quartz substrates, it can be prevented from leaking to the outside even if it becomes liquid. The insulator 300 is a plate-shaped substrate having the same external shape as the wafers 200. For example, the diameter (φ) of the insulator 300 is 320 mm and the thickness (d) is 2 mm. By sealing the heat storage material 301 with a quartz member 302 to form a plate, it can be treated as a component similar to the wafer 200 and loaded into the boat 217 in the same way as the product wafer 200, dummy wafers (dummy substrates), and heat insulating plates.

[0038] If the melting point of the heat storage material 301 is higher than the temperature inside the reaction tube 203, the heat storage material 301 is a solid; if it is lower than the temperature inside the reaction tube 203, the heat storage material 301 is a liquid. Details of the heat storage material 301 will be described later. As such a heat storage material 301, for example, a phase change material (PCM) can be used.

[0039] As shown in Figure 4, PCM is a substance that stores latent heat when it melts from solid to liquid at its melting point, and releases latent heat when it solidifies from liquid to solid. In other words, the heat storage material 301 has a melting point, and at its melting point, it is configured to either release latent heat or store latent heat. The heat storage material 301 has a constant temperature at its melting point. The heat storage material 301 is capable of accumulating or releasing latent heat at its melting point. Here, latent heat is heat that does not involve a change in temperature (heat that changes the state of a substance). Latent heat storage (latent heat release) is heat storage (heat release) that utilizes the thermal energy required for phase change, that is, for a change in the state of a substance (gas, liquid, solid).

[0040] As shown in Figure 5, the heat storage material 301 at its melting point can store more heat internally (heat storage capacity) than, for example, a substrate without heat storage properties such as an insulating board (sensible heat storage material: a solid component in which the temperature rise and the amount of heat stored are proportional), by storing latent heat in addition to sensible heat. For example, the amount of heat stored is 1.3 times that of a sensible heat storage material of the same volume. By utilizing this characteristic, the effect of heating the wafer 200 can be increased.

[0041] In the temperature range where no phase change occurs (temperatures other than the melting point), the heat storage material 301 releases sensible heat when its temperature decreases and stores sensible heat when its temperature increases. In other words, the heat storage material 301 is configured to decrease in temperature while releasing heat and to increase in temperature while storing heat. As a result, the wafer 200 placed near the heat storage material 301 is heated by the heat released by the heat storage material 301. Sensible heat is heat that is accompanied by a temperature change (heat that changes the temperature of a substance). Sensible heat storage (sensible heat release) is heat storage (heat release) that utilizes the specific heat of a substance, that is, the thermal energy required to change its temperature.

[0042] An example of the arrangement of the heat insulator 300 provided near the wafer 200 will be described with reference to FIGS. 6(a) to 6(e).

[0043] In FIGS. 6(a) to 6(e), the plate-shaped heat insulator 300 shown in FIG. 3 is loaded into the support portion that supports the wafer 200 and the heat insulating plate 310 of the boat 217, so that the heat insulator 300 is arranged near the wafer 200. More specifically, as shown in FIG. 6(a), the boat 217 is configured to be able to hold a plurality of wafers 200 and heat insulating plates 310. The boat 217 is divided into a substrate processing region SPA where the wafer 200 is held and a heat insulating region IA where the heat insulating plate 310 is held, and is configured such that the heat insulator 300 is held at least at the upper end of the heat insulating region IA. In FIG. 6(a), three heat insulators 300 are arranged below (directly below) five wafers 200 from the upper end of the heat insulating region IA. This is an example, and the number of these is not limited.

[0044] As described above, since the heat insulator 300 can be loaded into the boat 217 in the same manner as plate-shaped substrates such as the wafer 200, the dummy substrate, and the heat insulating plate, it can be arranged near the wafer 200. As shown in FIG. 6(a), it can be arranged at the upper end portion of the heat insulating region IA instead of the heat insulating plate 310.

[0045] The upper end portion of the heat insulating region IA is a region where the heater 207 is arranged on the side surface of the heat insulator 300, and the heat insulator 300 is arranged at the upper end portion so as to face the heater 207. When the temperature inside the reaction tube 203, which is the temperature inside the furnace, is higher than the temperature of the heat insulator 300, as shown by the arrow in FIG. 6(a), the heat insulator 300 stores heat by the heating of the heater 207. When the temperature inside the furnace is lower than the temperature of the heat insulator 300, as shown by the arrow in FIG. 6(b), the wafer 200 arranged near the heat insulator 300 is heated by the heat radiation from the heat insulator 300.

[0046] As described above, by providing the heat insulator 300 including the heat storage material 301 at the upper end portion of the heat insulating region IA, the heat storage material 301 can heat the wafer 200 at the lower end portion of the substrate processing region SPA. Thereby, the inside of the surface of the wafer 200 can be heated evenly.

[0047] As shown in FIG. 6(c), the boat 217 may be configured such that the heat insulator 300 is held at at least one of the lower end and the upper end of the substrate processing region SPA. Thereby, at least one of the lower end and the upper end of the wafer 200 in the substrate processing region SPA can be heated by the heat dissipation of the heat insulator 300. Thereby, the wafer 200 can be evenly heated within the surface thereof.

[0048] For example, the heat insulator 300 may be disposed instead of the side dummy substrate disposed below the wafer 200. Thereby, the wafer 200 close to the furnace mouth (close to the opening for loading and unloading the wafer 200) can be heated, and the in-plane temperature uniformity of the wafer 200 supported at the lower end of the substrate processing region SPA can be improved. For example, the heat insulator 300 may be disposed instead of the side dummy substrate above the wafer 200. Thereby, the influence due to heat retention can be reduced.

[0049] As shown in FIG. 6(d), at least one reflector 320 may be provided below the heat insulator 300. The reflector 320 is preferably disposed directly below the heat insulator 300.

[0050] By disposing the reflector 320, efficient heating of the wafer 200 can be expected. For example, in FIG. 6(b), the heat dissipation from the heat insulator 300 is directed toward the wafer 200. Although not shown, heat dissipation toward the lower side also occurs. Therefore, as shown in FIG. 6(d), by loading at least one reflector 320 below the three heat insulators 300, the heat dissipation toward the lower side can be directed upward. Since the heat dissipation downward of the heat insulator 300 can be reflected, the heating effect of the wafer 200 by providing the heat insulator 300 at the upper end of the heat insulation region IA can be increased.

[0051] In the arrangement of the heat insulating body 300 shown in Figure 6(c), the boat 217 may be configured to hold the reflector 320 so that it does not face the wafer 200 with the heat insulating body 300 in between. The reflector 320 can reflect the heat radiated downward or upward from the heat insulating body 300. Therefore, by providing the heat insulating body 300 at the upper or lower end of the boat 217, the heat insulating body 300 is placed in the vicinity of the wafer 200, thereby increasing the heating effect on the wafer 200.

[0052] In Figures 6(a) to 6(d), the heat insulating body 300 is positioned adjacent to at least one of the wafers 200 at the upper and lower ends of a plurality of wafer rows. The heat insulating body 300 may also be positioned within a plurality of wafer rows. In other words, the heat insulating body 300 may be positioned between two wafers 200. For example, as shown in Figure 6(e), the heat insulating body 300 may be positioned above and below a wafer 200, adjacent to it. In other words, one wafer 200 is positioned between two heat insulating bodies 300.

[0053] Furthermore, when the temperature of the insulator 300 matches the furnace temperature (processing temperature), if that matching temperature is not the melting point of the heat storage material 301, sensible heat is stored. By matching the temperature of the insulator 300 with the furnace temperature (the temperature at which the substrate is processed), or by setting the temperature of the insulator 300 slightly higher than the furnace temperature, the heating of the wafer 200 by heat dissipation from the insulator 300 can be made more efficient.

[0054] The use of overshoot in temperature control during the substrate processing process described above will be explained using Figure 7. In Figure 7, the temperature of the heat storage material 301 is shown by a solid line, and the furnace temperature is shown by a dashed line.

[0055] An insulating body 300 containing a heat storage material 301 having a melting point slightly higher than the processing temperature, which is the furnace temperature, is provided near the wafer 200. As shown in Figure 7, latent heat is stored in the heat storage material 301 during the period when the furnace temperature overshoots above the temperature (melting point) of the heat storage material 301. Latent heat is released from the heat storage material 301 during the period when the furnace temperature falls below the temperature of the heat storage material 301. After that, the furnace temperature and the temperature of the heat storage material 301 become the same. In other words, the heat storage material 301 stores heat during the overshoot relative to the set temperature (processing temperature) of the heater 207, and spontaneously releases heat from the furnace opening during film formation. This makes it possible to improve the in-plane uniformity of the wafer 200.

[0056] The RDD (Ramp Down Deposition) assistance in temperature control during the substrate processing process described above will be explained using Figure 8. In Figure 8, the temperature of the heat storage material 301 is shown by a solid line, and the furnace temperature is shown by a dashed line.

[0057] RDD is a film deposition method that lowers the furnace temperature. As the furnace temperature is lowered, the temperature cools from the edges of the wafer 200, and when film is deposited in this state, the film at the edges of the wafer 200 can be made thinner, improving in-plane uniformity. After the film deposition is complete, the temperature is raised, and then the next film deposition is performed.

[0058] Even with RDD alone, the temperature of the wafer 200 decreases from the edges, improving the concave distribution of the film within the wafer 200's plane. A concave distribution is one in which the film is thin in the center of the wafer 200 and thicker at the edges. The presence of an insulating material 300 near the wafer 200 enhances the RDD effect. Alternatively, it is possible to create a convex distribution of the film within the wafer 200's plane more quickly. A convex distribution is one in which the film is thicker in the center of the wafer 200 and thinner at the edges. This makes it possible to shorten the film deposition time for the recipe.

[0059] As shown in Figure 8, during the film deposition period, the furnace temperature decreases over time. Meanwhile, the heat storage material 301 maintains a constant temperature while releasing heat. Therefore, the wafer 200 near the insulator 300 containing the heat storage material 301 is heated. During the heating period, the furnace temperature rises over time. Meanwhile, the heat storage material 301 maintains a constant temperature while storing heat. In other words, the heat storage material 301 stores or releases heat while maintaining a constant temperature in the latent heat region. Since there is a heating source at a constant temperature higher than the heater set temperature, it helps to create a convex distribution.

[0060] As described above, this embodiment includes an insulating body 300 containing a heat storage material 301 that is placed near a substrate housed in a reaction vessel configured to be heated to a predetermined temperature. This provides one or more of the following effects.

[0061] (a) According to this embodiment, the wafer 200 can be heated by utilizing the heat storage and heat release of the heat storage material 301, thereby improving the uniformity of the in-plane temperature of the wafer 200.

[0062] (b) According to this embodiment, the effect of heat escape can be reduced, so that the temperature uniformity of the wafer 200 placed near the furnace opening can be improved.

[0063] (c) According to this embodiment, the effects of heat retention can be reduced, making it possible to improve the temperature uniformity of the wafer 200 at the upper end of the substrate processing area SPA.

[0064] (d) Furthermore, according to this embodiment, by improving the temperature uniformity of the wafer 200 located near the furnace opening, an improvement in temperature uniformity between the wafers 200 can be expected.

[0065] (e) According to this embodiment, the wafer 200 can be heated by utilizing the heat storage effect without providing a heater (for example, a heater that heats the furnace opening). Therefore, since no heater is provided, costs can be reduced.

[0066] (f) Furthermore, according to this embodiment, since no heater is provided, there is naturally no need for a power supply (electricity) for a heater. This makes energy saving possible.

[0067] The above describes one aspect of this disclosure in detail, but this disclosure is not limited to the above-described aspect and can be modified in various ways without departing from its essence.

[0068] Furthermore, in the embodiments described above, film deposition was used as the processing performed by the substrate processing apparatus. This disclosure is not limited to this and can be applied not only to semiconductor manufacturing apparatus but also to apparatus that process glass substrates, such as LCD apparatus. Film deposition processes include, for example, processes for forming CVD, PVD, oxide films, nitride films, or both, and processes for forming metal-containing films. Moreover, the disclosure is similarly applicable even when processes such as annealing, oxidation, nitriding, and diffusion are performed.

[0069] Furthermore, the above-described embodiments described an example of forming a film using a batch-type substrate processing apparatus that processes multiple substrates at once. This disclosure is not limited to the above-described embodiments and can be suitably applied, for example, to forming a film using a single-wafer substrate processing apparatus that processes one or several substrates at once. Furthermore, the above-described embodiments described an example of forming a film using a substrate processing apparatus having a hot-wall type processing furnace. This disclosure is not limited to the above-described embodiments and can be suitably applied to forming a film using a substrate processing apparatus having a cold-wall type processing furnace.

[0070] Even when using these substrate processing devices, each process can be carried out using the same processing procedures and conditions as described above, and the same effects as described above can be obtained.

[0071] While various typical embodiments of this disclosure have been described above, this disclosure is not limited to these embodiments and can be used in combination as appropriate.

[0072] 1: Substrate processing device 300: Insulator 301: Heat storage material

Claims

1. A substrate processing apparatus having an insulating body containing a heat storage material placed near a substrate housed in a reaction vessel configured to be heated to a predetermined temperature, wherein the heat storage material is solid if its melting point is higher than the predetermined temperature, and liquid if its melting point is lower than the predetermined temperature.

2. The substrate processing apparatus according to claim 1, wherein the insulating body is configured to seal the heat storage material with a quartz member.

3. The substrate processing apparatus according to claim 1, wherein the heat storage material is configured to perform either latent heat dissipation or latent heat storage at its melting point.

4. The substrate processing apparatus according to claim 3, wherein the heat storage material has a constant temperature at the melting point.

5. The substrate processing apparatus according to claim 1, wherein the heat storage material is configured to decrease in temperature while dissipating heat and increase in temperature while storing heat.

6. The substrate processing apparatus according to claim 5, wherein the substrate, which is placed near the heat storage material, is configured to be heated by the heat dissipation of the heat storage material.

7. The substrate processing apparatus according to claim 1, wherein the insulating body is configured to heat the substrate by dissipating heat from the heat storage material, which has a melting point above the predetermined temperature and at least a portion of it is in a liquid state.

8. The substrate processing apparatus according to claim 1, further comprising a holder for holding a plurality of substrates and insulating plates, wherein the holder is divided into a substrate processing area for holding the substrates and an insulating area for holding the insulating plates, and is configured such that the insulating body is held at least at the upper end of the insulating area.

9. The substrate processing apparatus according to claim 8, wherein the substrate at the lower end of the substrate processing area is configured to be heated by the heat dissipation of the heat storage material.

10. The substrate processing apparatus according to claim 8, wherein the insulating material is provided in multiple layers from the upper end of the insulating region.

11. The substrate processing apparatus according to claim 8, wherein the upper end of the heat insulating region is a region on the side surface of the heat insulating plate where a heating element is arranged, and the heat insulating body is arranged at the upper end so as to face the heating element.

12. The substrate processing apparatus according to claim 8, further comprising at least one reflector below the heat insulating body.

13. The substrate processing apparatus according to claim 12, wherein the reflector is disposed directly below the heat insulating body.

14. The substrate processing apparatus according to claim 1, further comprising a holder having a substrate processing region for holding a plurality of substrates, wherein the holder is configured such that the heat insulating body is held at least one of the lower end and upper end of the substrate processing region.

15. The substrate processing apparatus according to claim 14, wherein the holder is configured to hold the reflector so as not to be in contact with the substrate, with the heat insulating material interposed between them.

16. A method for heating a substrate, comprising the steps of: preparing a substrate processing apparatus, which is placed near a substrate housed in a reaction vessel configured to be heated to a predetermined temperature, and which has an insulating body containing a heat storage material, wherein the heat storage material is solid if its melting point is higher than the predetermined temperature, and liquid if its melting point is lower than the predetermined temperature; and heating the substrate in the reaction vessel.

17. A method for manufacturing a semiconductor device, comprising the step of processing a substrate using the substrate heating method described in claim 16.

Images