JP7534458B2 - Substrate processing apparatus, semiconductor device manufacturing method and program - Google Patents

Description

This disclosure relates to a substrate processing apparatus, a method for manufacturing a semiconductor device, and a program.

As one step in the manufacturing process of semiconductor devices, there is a modification process typified by annealing, in which a heating device is used to heat a substrate in a processing chamber to change the composition and crystal structure in a thin film formed on the surface of the substrate, or to repair crystal defects in the thin film. In recent years, semiconductor devices have become significantly finer and more highly integrated, and this has led to a demand for modification processes for high-density substrates on which patterns with high aspect ratios are formed. As a method for modifying such high-density substrates, a heat treatment method using electromagnetic waves, as seen in Patent Document 1, for example, has been considered.

JP 2015-070045 A

In conventional processes using electromagnetic waves, heat treatment can cause the semiconductor substrate to warp or crack due to uneven temperature across the substrate.

This disclosure provides technology that makes it possible to prevent substrate warping and cracking due to heat treatment.

According to one aspect of the present disclosure, a technology is provided that includes a processing chamber for processing multiple substrates held by a substrate holder, an electromagnetic wave generator for supplying electromagnetic waves into the processing chamber, and a gas supply unit for supplying cooling gas between the multiple substrates from multiple gas supply ports provided to match the spacing between the multiple substrates.

This disclosure makes it possible to prevent warping and cracking of the substrate due to heat treatment.

1 is a schematic configuration diagram showing, in vertical cross section, a processing furnace portion of a substrate processing apparatus suitably used in an embodiment of the present disclosure; 1 is a longitudinal sectional view showing a schematic configuration of a substrate processing apparatus suitably used in an embodiment of the present disclosure, at the position of a processing furnace. 1 is a cross-sectional view showing a cross-sectional configuration of a substrate processing apparatus preferably used in an embodiment of the present disclosure. FIG. 2 is a schematic configuration diagram of a controller of a substrate processing apparatus preferably used in an embodiment of the present disclosure. 1A and 1B are diagrams for explaining heat build-up in a substrate processing apparatus preferably used in an embodiment of the present disclosure. 4A to 4C are diagrams for explaining hole spacing, the number of holes, and hole diameters of a nozzle of a substrate processing apparatus preferably used in an embodiment of the present disclosure, and examples thereof. 13A and 13B are diagrams showing the results of changing the blowing direction of a nozzle of a substrate processing apparatus preferably used in an embodiment of the present disclosure toward a substrate. 1A and 1B are diagrams for explaining an example of installation of a plurality of nozzles in a substrate processing apparatus suitably used in an embodiment of the present disclosure. 11A and 11B are diagrams showing blowing control to a hot spot of a nozzle of a substrate processing apparatus preferably used in an embodiment of the present disclosure. FIG. 1 is a diagram showing an example of a flow of a substrate processing method preferably used in an embodiment of the present disclosure. FIG. 1 is a diagram showing an example of a substrate processing apparatus equipped with a thermo camera that is preferably used in an embodiment of the present disclosure. 11A to 11C are diagrams showing an example of a simulation result of a substrate processing apparatus preferably used in an embodiment of the present disclosure.

Embodiments of the present disclosure will be described below with reference to Figures 1 to 11. Note that all drawings used in the following description are schematic, and the dimensional relationships between elements, the ratios of elements, etc. shown in the drawings do not necessarily match those in reality. Furthermore, the dimensional relationships between elements, the ratios of elements, etc. do not necessarily match between multiple drawings.

Embodiments of the present disclosure will be described below with reference to the drawings.

(1) Configuration of the Substrate Processing Apparatus The substrate processing apparatus according to the embodiment of the present disclosure is configured as a single-wafer heat processing apparatus that performs various heat treatments on a plurality of wafers, and will be described as an apparatus that performs an annealing process (i.e., a modification process) using electromagnetic waves, which will be described later. In the substrate processing apparatus in this embodiment, a FOUP (Front Opening Unified Pod: hereinafter, referred to as a pod) is used as a storage container (carrier) that contains wafers as substrates inside a processing chamber. The pod is also used as a transport container for transporting wafers between various substrate processing apparatuses.

As shown in Figures 1, 2 and 3, the substrate processing apparatus 100 includes a transport housing 202 having a transport chamber 203 therein for transporting the wafer 200, and cases 102-1 and 102-2, which are provided on the side walls of the transport housing 202 and serve as processing vessels having processing chambers 201-1 and 201-2 therein for processing the wafer 200, as described below. In addition, a cooling case 109 that forms a cooling chamber 204 is provided between the processing chambers 201-1 and 201-2.

2 (lower side in FIG. 3 ), which is the front side of the transport housing 202, a load port unit (LP) 106 is disposed as a pod opening/closing mechanism for opening and closing the lid of the pod 110 and loading/unloading the wafer 200 into/from the transport chamber 203. The load port unit 106 includes a housing 106a, a stage 106b, and an opener 106c. The stage 106b is configured to place the pod 110 thereon and bring the pod 110 close to a substrate loading/unloading port 134 formed in the front of the housing of the transport chamber 203, and the opener 106c opens and closes a lid (not shown) provided on the pod 110. The load port unit 106 may also have a function capable of purging the inside of the pod 110 with a purge gas such as N ₂ gas. The transport housing 202 also has a purge gas circulation structure (described later) for circulating the purge gas in the transport chamber 203.

Gate valves (GV) 205-1 and 205-2 for opening and closing the processing chambers 201-1 and 201-2 are disposed on the rear side of the transfer housing 202, on the left side as viewed in FIG. 2 (upper side as viewed in FIG. 3). A substrate transfer robot, which is a substrate transfer mechanism for transferring the wafer 200, and a transfer machine 125 as a substrate transfer section are disposed in the transfer chamber 203. The transfer machine 125 is composed of tweezers (arms) 125a-1 and 125a-2 as a placement section for placing the wafer 200, a transfer device 125b that can rotate or move each of the tweezers 125a-1 and 125a-2 horizontally, and a transfer device elevator 125c that raises and lowers the transfer device 125b. The continuous operation of the tweezers 125a-1, 125a-2, the transfer device 125b, and the transfer device elevator 125c allows the wafers 200 to be charged or discharged from the substrate holder (substrate holder) 217, the cooling chamber 204, and the pod 110, which will be described later. Hereinafter, the cases 102-1, 102-2, the processing chambers 201-1, 201-2, and the tweezers 125a-1 and 125a-2 will be simply referred to as the case 102, the processing chamber 201, and the tweezers 125a, respectively, when there is no need to distinguish between them.

The tweezers 125a-1 are made of normal aluminum material and are used to transport low-temperature and room-temperature wafers. The tweezers 125a-2 are made of aluminum, quartz, or other material that has high heat resistance and poor thermal conductivity and are used to transport high-temperature and room-temperature wafers. In other words, the tweezers 125a-1 are low-temperature substrate transport parts, and the tweezers 125a-2 are high-temperature substrate transport parts. The high-temperature tweezers 125a-2 are preferably configured to have a heat resistance of, for example, 100°C or higher, and more preferably, 200°C or higher. A mapping sensor can be installed on the low-temperature tweezers 125a-1. By providing a mapping sensor on the low-temperature tweezers 125a-1, it becomes possible to check the number of wafers 200 in the load port unit 106, the number of wafers 200 in the reaction chamber 201, and the number of wafers 200 in the cooling chamber 204.

In the substrate processing apparatus according to the embodiment of the present disclosure, the tweezers 125a-1 are described as low-temperature tweezers, and the tweezers 125a-2 are described as high-temperature tweezers, but the present disclosure is not limited to this. The tweezers 125a-1 may be made of a material with high heat resistance and poor thermal conductivity, such as aluminum or quartz, and used to transport high-temperature and room-temperature wafers, and the tweezers 125a-2 may be made of a normal aluminum material and used to transport low-temperature and room-temperature wafers. In addition, both the tweezers 125a-1 and 125a-2 may be made of a material with high heat resistance and poor thermal conductivity, such as aluminum or quartz.

(Processing furnace)
In an area A enclosed by a dashed line in Fig. 2, a processing furnace (processing chamber) 201 having a substrate processing structure as shown in Fig. 1 is configured. As shown in Fig. 3, a plurality of processing furnaces are provided in this embodiment, but since the processing furnaces have the same configuration, only the configuration of one of them will be described and the description of the configuration of the other processing furnace will be omitted.

As shown in FIG. 1, the processing furnace has a case 102 as a cavity (processing vessel) made of a material that reflects electromagnetic waves, such as metal. A cap flange (closing plate) 104 made of a metal material closes the upper end of the case 102 via an O-ring (not shown) as a sealing member. The inner space of the case 102 and the cap flange 104 mainly constitutes a processing chamber 201 for processing substrates such as silicon wafers. A reaction tube (not shown) made of quartz that transmits electromagnetic waves may be installed inside the case 102, or the processing vessel may be configured so that the inside of the reaction tube serves as the processing chamber. Alternatively, the processing chamber 201 may be formed using a case 102 with a closed ceiling without providing the cap flange 104.

A mounting table 210 is provided in the processing chamber 201, and a boat 217 is placed on the upper surface of the mounting table 210 as a substrate holder that holds a wafer 200 as a substrate. The boat 217 holds the wafer 200 to be processed and susceptors 103a and 103b placed vertically above and below the wafer 200 so as to sandwich the wafer 200 at a predetermined interval. The susceptors 103a and 103b are made of materials such as silicon plates (Si plates) and silicon carbide plates (SiC plates) and are arranged above and below the wafer 200 to suppress the concentration of electric field intensity on the edge of the wafer 200. In other words, the susceptor suppresses the absorption of electromagnetic waves by the edge of the wafer. Quartz plates 101a and 101b as heat insulating plates may also be held at a predetermined interval on the upper and lower surfaces of the susceptors 103a and 103b. In this embodiment, the quartz plates 101a and 101b and the susceptors 103a and 103b are each composed of the same parts, and hereafter, unless there is a need to distinguish between them, they will be referred to as the quartz plate 101 and the susceptor 103.

The case 102 as a processing vessel is, for example, circular in cross section and configured as a flat sealed vessel. The transport housing 202 as a lower vessel is configured, for example, of a metal material such as aluminum (Al) or stainless steel (SUS), or quartz. The space surrounded by the case 102 may be referred to as the processing chamber 201 or reaction area 201 as a processing space, and the space surrounded by the transport housing 202 may be referred to as the transport chamber or transport area 203 as a transport space. The processing chamber 201 and the transport chamber 203 are not limited to being configured adjacent to each other in the horizontal direction as in this embodiment, but may also be configured adjacent to each other in the vertical direction and to raise and lower a substrate holder having a predetermined structure.

As shown in Figures 1, 2 and 3, a substrate loading/unloading port 206 adjacent to a gate valve 205 is provided on the side of the transport housing 202, and the wafer 200 moves between the processing chamber 201 and the transport chamber 203 through the substrate loading/unloading port 206. A choke structure having a length of 1/4 the wavelength of the electromagnetic wave used is provided around the gate valve 205 or the substrate loading/unloading port 206 as a measure against leakage of the electromagnetic wave, which will be described later.

An electromagnetic wave supply unit serving as a heating device, which will be described in detail later, is installed on the side of the case 102, and electromagnetic waves such as microwaves supplied from the electromagnetic wave supply unit are introduced into the processing chamber 201 to heat the wafers 200, etc., and process the wafers 200.

The mounting table 210 is supported by a shaft 255 as a rotation axis. The shaft 255 passes through the bottom of the processing chamber 201 and is connected to a drive mechanism 267 that performs a rotation operation outside the processing chamber 201. By operating the drive mechanism 267 to rotate the shaft 255 and the mounting table 210, it is possible to rotate the wafer 200 placed on the boat 217. The lower end of the shaft 255 is surrounded by a bellows 212, and the processing chamber 201 and the transfer area 203 are kept airtight.

Here, the mounting table 210 may be configured to be raised or lowered by the drive mechanism 267 depending on the height of the substrate loading/unloading port 206 so that when the wafer 200 is being transported, the wafer 200 is moved up or down to a wafer transport position, and when the wafer 200 is being processed, the wafer 200 is moved up or down to a processing position (wafer processing position) within the processing chamber 201.

Below the processing chamber 201, on the outer periphery of the mounting table 210, an exhaust section is provided to exhaust the atmosphere of the processing chamber 201. As shown in FIG. 1, the exhaust section is provided with an exhaust port 221. An exhaust pipe 231 is connected to the exhaust port 221, and a pressure regulator 244 such as an APC valve that controls the valve opening depending on the pressure inside the processing chamber 201, and a vacuum pump 246 are connected in series to the exhaust pipe 231.

Here, the pressure regulator 244 is not limited to an APC valve, and may be configured to use both a normal opening/closing valve and a pressure adjustment valve, as long as it can receive pressure information within the processing chamber 201 and a feedback signal from a pressure sensor 245 (described later) and adjust the exhaust volume.

The exhaust section (also called the exhaust system or exhaust line) is mainly composed of the exhaust port 221, the exhaust pipe 231, and the pressure regulator 244. The exhaust system may also include a vacuum pump 246. In addition, exhaust ports may be provided to surround the mounting table 210, allowing gas to be exhausted from the entire circumference of the wafer 200.

The cap flange 104 is provided with a gas supply pipe 232 for supplying various processing gases for substrate processing, such as an inert gas, a raw material gas, and a reaction gas, into the processing chamber 201. The gas supply pipe 232 is provided with a mass flow controller (MFC) 241, which is a flow rate controller (flow rate control unit), and a valve 243, which is an on-off valve, in that order from upstream. For example, an inert gas source is connected to the upstream side of the gas supply pipe 232, and the gas is supplied into the processing chamber 201 via the MFC 241 and the valve 243. When multiple types of gas are used during substrate processing, multiple types of gas can be supplied by using a configuration in which a gas supply pipe provided with an MFC, which is a flow rate controller, and a valve, which is an on-off valve, is connected downstream of the valve 243 of the gas supply pipe 232 in that order from the upstream side. A gas supply pipe provided with an MFC and a valve for each gas type may be installed.

The process chamber 201 is provided with a nozzle 105 connected to a gas supply pipe 232. A gas supply port is provided on the side of the nozzle 105 for supplying gas. The gas supply port opens toward the wafer 200 and supplies gas parallel to the surface of the wafer 200. A plurality of gas supply ports are provided from the bottom to the top of the process chamber 201 (i.e., in the direction (vertical direction) in which the wafer 200 is held (loaded) on the substrate holder 217) so as to match the intervals between the wafers 200 held by the substrate holder 217. Each of the plurality of gas supply ports has the same opening area, and is provided at the same opening pitch.
A gas supply system (gas supply unit) is mainly composed of the gas supply pipe 232, the MFC 241, the valve 243, and the nozzle 105. When an inert gas is flowed through the gas supply system, it is also called an inert gas supply system. As the inert gas, for example, _N2 gas or a rare gas such as Ar gas, He gas, Ne gas, or Xe gas can be used.

The cap flange 104 is provided with a temperature sensor 263 as a non-contact temperature measuring device. The output of the microwave oscillator 655 described later is adjusted based on the temperature information detected by the temperature sensor 263 to heat the substrate and obtain the desired temperature distribution of the substrate temperature. The temperature sensor 263 is, for example, a radiation thermometer such as an IR (Infrared Radiation) sensor. The temperature sensor 263 is installed to measure the surface temperature of the quartz plate 101a or the surface temperature of the wafer 200. If a susceptor is provided as the heating element described above, the temperature sensor 263 may be configured to measure the surface temperature of the susceptor. In this embodiment, the term "wafer temperature" refers to the wafer temperature converted by the temperature conversion data described later, that is, the estimated wafer temperature, the temperature obtained by directly measuring the temperature of the wafer 200 by the temperature sensor 263, or both of them.

The temperature sensor 263 may acquire the temperature change trends for the quartz plate 101 or susceptor 103 and the wafer 200 in advance, and store temperature conversion data showing the correlation between the temperatures of the quartz plate 101 or susceptor 103 and the wafer 200 in the storage device 121c or the external storage device 123. By creating the temperature conversion data in advance in this manner, the temperature of the wafer 200 can be estimated by measuring only the temperature of the quartz plate 101, and the output of the microwave oscillator 655, i.e., the heating device, can be controlled based on the estimated temperature of the wafer 200.

The temperature measurement unit for measuring the temperature of the substrate is not limited to the radiation thermometer described above. Temperature measurement may be performed using a thermocouple, or a combination of a thermocouple and a non-contact thermometer. However, when temperature measurement is performed using a thermocouple, the thermocouple must be placed near the wafer 200 to perform the temperature measurement. In other words, since the thermocouple must be placed inside the processing chamber 201, the thermocouple itself is heated by the microwaves supplied from the microwave oscillator described below, making it impossible to measure the temperature accurately. Therefore, it is preferable to use a non-contact thermometer as the temperature sensor 263.

The temperature sensor 263 is not limited to being provided on the cap flange 104, but may be provided on the mounting base 210. The temperature sensor 263 may not only be directly provided on the cap flange 104 or mounting base 210, but may also be configured to indirectly measure the temperature by reflecting the radiation from a measurement window provided on the cap flange 104 or mounting base 210 with a mirror or the like. The temperature sensor 263 is not limited to being provided in a single unit, but may be provided in multiple units.

Electromagnetic wave introduction ports 653-1 and 653-2 are installed on the side wall of the case 102. One end of waveguides 654-1 and 654-2 for supplying electromagnetic waves (microwaves) into the processing chamber 201 is connected to each of the electromagnetic wave introduction ports 653-1 and 653-2. Microwave oscillators (electromagnetic wave source, electromagnetic wave generator) 655-1 and 655-2 are connected to the other end of each of the waveguides 654-1 and 654-2 as heating sources that supply electromagnetic waves into the processing chamber 201 to heat it. The microwave oscillators 655-1 and 655-2 supply electromagnetic waves such as microwaves to the waveguides 654-1 and 654-2, respectively. In addition, magnetrons, klystrons, etc. are used as the microwave oscillators 655-1 and 655-2. Hereinafter, when there is no need to distinguish between the electromagnetic wave introduction ports 653-1 and 653-2, the waveguides 654-1 and 654-2, and the microwave oscillators 655-1 and 655-2, they will be referred to as the electromagnetic wave introduction port 653, the waveguide 654, and the microwave oscillator 655.

The frequency of the electromagnetic waves generated by microwave oscillator 655 is preferably controlled to be in the frequency range of 13.56 MHz to 24.125 GHz. More preferably, it is controlled to be 2.45 GHz or 5.8 GHz. Here, the frequencies of microwave oscillators 655-1 and 655-2 may be the same or different.

In addition, in this embodiment, two microwave oscillators 655 are described as being arranged on the side of the case 102, but this is not limiting and one or more may be provided, and the case 102 may be arranged so as to be arranged on different side surfaces, such as opposing side surfaces. An electromagnetic wave supply unit (also referred to as an electromagnetic wave supply unit, microwave supply unit, or microwave supply unit) serving as a heating device is mainly composed of microwave oscillators 655-1, 655-2, waveguides 654-1, 654-2, and electromagnetic wave introduction ports 653-1, 653-2.

The microwave oscillators 655-1 and 655-2 are each connected to a controller 121, which will be described later. The controller 121 is connected to a temperature sensor 263 that measures the temperature of the quartz plate 101a or 101b or the wafer 200 housed in the processing chamber 201. The temperature sensor 263 measures the temperature of the quartz plate 101 or the wafer 200 using the method described above and transmits it to the controller 121, which then controls the output of the microwave oscillators 655-1 and 655-2 to control the heating of the wafer 200. As a method for controlling the heating using the heating device, a method for controlling the heating of the wafer 200 by controlling the voltage input to the microwave oscillator 655, and a method for controlling the heating of the wafer 200 by changing the ratio of the time when the microwave oscillator 655 is turned on to the time when it is turned off can be used.

Here, the microwave oscillators 655-1 and 655-2 are controlled by the same control signal transmitted from the controller 121. However, this is not limited to the above, and the microwave oscillators 655-1 and 655-2 may be configured to be individually controlled by transmitting individual control signals from the controller 121 to each of the microwave oscillators 655-1 and 655-2.

(Control device)
As shown in Fig. 4, the controller 121, which is a control unit (control device, control means), is configured as a computer including a CPU (Central Processing Unit) 121a, a RAM (Random Access Memory) 121b, a storage device 121c, and an I/O port 121d. The RAM 121b, the storage device 121c, and the I/O port 121d are configured to be able to exchange data with the CPU 121a via an internal bus 121e. An input/output device 122 configured as, for example, a touch panel, is connected to the controller 121.

The storage device 121c is composed of, for example, a flash memory, a HDD (Hard Disk Drive), etc. In the storage device 121c, a control program for controlling the operation of the substrate processing device, a process recipe in which the procedure and conditions of the annealing (modification) process are described, etc. are readably stored. The process recipe is a combination of procedures in the substrate processing process described later that are executed by the controller 121 to obtain a predetermined result, and functions as a program. Hereinafter, the process recipe and the control program are collectively referred to simply as a program. In addition, the process recipe is also simply referred to as a recipe. When the word program is used in this specification, it may include only a recipe, only a control program, or both. The RAM 121b is configured as a memory area (work area) in which the programs and data read by the CPU 121a are temporarily stored.

The I/O port 121d is connected to the above-mentioned transfer machine 125, MFC 241, valve 243, pressure sensor 245, APC valve 244, vacuum pump 246, temperature sensor 263, drive mechanism 267, microwave oscillator 655, etc.

The CPU 121a is configured to read and execute a control program from the storage device 121c, and to read a recipe from the storage device 121c in response to input of an operation command from the input/output device 122, etc. The CPU 121a is configured to be able to control the transfer operation of the substrate by the transfer machine, the flow rate adjustment operation of various gases by the MFC 241, the opening and closing operation of the valve 243, the pressure adjustment operation by the APC valve 244 based on the pressure sensor 245, the start and stop of the vacuum pump 246, the output adjustment operation of the microwave oscillator 655 based on the temperature sensor 263, the rotation and rotation speed adjustment operation of the mounting table 210 (or the boat 217) by the drive mechanism 267, or the lifting and lowering operation, etc., in accordance with the contents of the read recipe.

The controller 121 can be configured by installing the above-mentioned program stored in an external storage device (for example, a magnetic disk such as a hard disk, an optical disk such as a CD, a magneto-optical disk such as an MO, or a semiconductor memory such as a USB memory) 123 into a computer. The storage device 121c and the external storage device 123 are configured as computer-readable recording media. Hereinafter, these will be collectively referred to as recording media. When the term recording media is used in this specification, it may include only the storage device 121c alone, only the external storage device 123 alone, or both. The program may be provided to the computer using a communication means such as the Internet or a dedicated line, without using the external storage device 123.

In this embodiment, by supplying cooling gas from a nozzle while heating the substrate, the substrate is maintained at a predetermined temperature while irradiating it with microwaves for a predetermined time, thereby maintaining the substrate at a predetermined temperature and suppressing temperature variations on the wafer substrate, thereby suppressing the occurrence of warping and cracking of the semiconductor substrate. This embodiment improves the processing quality of the semiconductor substrate (or reduces processing defects), suppresses warping and cracking, and increases the number of substrates that can be processed simultaneously by spraying gas from a nozzle to improve the in-plane temperature uniformity of the semiconductor substrate, thereby fully resolving the problems with the prior art described above.

An example of the conditions of the gas nozzle (nozzle) 105 serving as a gas supply unit according to this embodiment shown in Fig. 6 is shown below. The gas nozzle 105 is provided in the processing chamber 201 and supplies gas to the wafer 200.
Hole spacing: Same as wafer spacing.
Gas flow rate: The flow rate of the gas supplied to each wafer is set to 1 slm or more and 50 slm or less.
Gas flow velocity: The flow velocity of the gas supplied to each wafer is set to 0.2 m/s or more and 40.0 m/s or less.
Number of gas supply holes: equal to the number of wafers and susceptors. Specifically, in the case of five wafers and two susceptors arranged above and below the wafers, the number of holes is seven.
Hole diameter: Φ0.2 mm or more and Φ5.0 mm or less. The smaller the hole diameter, the faster the gas flow rate can be, and the gas flow rate can be reduced. Also, heat loss can be minimized.
Regarding the gas flow rate, if it is less than 1 slm, the gas may not reach the center of the wafer, and if it exceeds 50 slm, the gas supply amount becomes excessive, leading to waste of cooling gas. Regarding the gas flow rate, if it is less than 0.2 m/s, the gas may not reach the center of the wafer, and if it exceeds 40.0 m/s, the gas that has passed between the wafers hits the wall surface, causing the gas flow to become turbulent and adversely affecting the wafer. Regarding the hole diameter, if it is less than Φ0.2 mm, it is difficult to process, and if it exceeds Φ5.0 mm, a large amount of gas must be used to ensure a predetermined gas flow rate, which may result in waste of gas. By performing heat treatment (modification treatment) while supplying gas between the substrates using a nozzle, it is possible to reduce processing defects of the substrate, prevent warping and cracking, and increase the number of substrates that can be processed simultaneously.

By providing a gas nozzle as a gas supply section and supplying gas between the substrates, it is possible to improve uniformity within the substrate surface.

Figure 7 shows the change in uniformity when the nozzle direction is adjusted in this embodiment. As shown in the figure, the in-plane uniformity can be improved by shifting the direction of the gas nozzle 105, which serves as the gas supply unit, from the center of the substrate toward the edge, for example by adjusting it in a 1/2 direction from the center of the substrate to the edge. Uniformity is improved by flowing cooling gas between the wafers and removing excess heat buildup. As shown in Figure 5, heat buildup is greater at the center of the wafer, but if the nozzle 105 is facing the center, only the center of the wafer will be too cold. On the other hand, the cooling gas coming out of the nozzle 105 has a wide spread, so even if it is not facing the wafer center, it is possible to remove heat buildup at the center of the wafer.

(Microwave cycle supply)
When microwaves are applied to the wafer intermittently, the location where gas is supplied to the rotating substrate is changed (in other words, the timing is staggered so that the gas is not supplied to the same location). The heat generated when the microwaves are supplied (On) is removed by cooling gas, and when the microwaves are stopped (Off), the supply of cooling gas is reduced or stopped to prevent the wafer from cooling down too much. Note that in cases where the wafer becomes suddenly high or when microwaves with high output are applied for heating, the cooling gas may be supplied without reducing or stopping the supply of cooling gas when the microwaves are Off.

Furthermore, by making the microwave output (power) power On/Off cycle and the wafer rotation not synchronized, it is possible to reduce the impact on the in-plane distribution. Specifically, the time for one rotation (in this case, 60/rpm) and the microwave cycle (i.e., the On+Off time) are controlled so that they are not an integer multiple. Figure 11 shows an example of a simulation result of the wafer rotation speed and the microwave ON/OFF cycle. In this embodiment, the microwave ON: 2 seconds, OFF: 4 seconds. If the wafer rotation speed is 2.5 rpm, the supply of cooling gas will overlap with a specific part of the wafer, and the specific part will be cooled. In other words, if the microwave ON/OFF cycle and the wafer rotation are synchronized, the same parts may overlap and deteriorate the in-plane distribution. On the other hand, if the wafer rotation speed is 2.4 rpm, the supply of cooling gas will be dispersed from a specific part of the wafer. Furthermore, at 2.3 rpm, the supply of cooling gas to the wafer is further dispersed, allowing for more uniform cooling across the wafer surface.

Figure 8A shows an embodiment in which multiple nozzles 105 are installed, making it possible to adjust the gas flow rate for each substrate. For example, by installing the same number of nozzles 105 as the number of wafers, it becomes possible to make fine adjustments for each wafer. The conditions to be adjusted include the flow rate of the cooling gas and the direction in which the cooling gas is supplied. By measuring multiple points on the top wafer with an IR sensor, such as the center, edges, and spaces between them, it becomes possible to supply cooling gas toward the hotter parts and to supply a larger amount of cooling gas to the hotter parts, thereby improving the cooling efficiency.

(Board warpage control)
During preheating of the substrate, the gas flow rate, direction, and timing are controlled to reduce the temperature difference within the substrate surface and suppress deformation (e.g., warping). Furthermore, it is more effective to control the flow by detecting it with an IR sensor or a thermo camera. If a thermo camera 111 as shown in FIG. 10 is used, one camera can function as multiple IR sensors and accurately measure the temperature distribution. If the temperature is measured from diagonally above the wafer, the temperature between the wafers can be measured. FIG. 8B shows how gas is flowed to target the hot spot 700. Since deformation can be suppressed without cooling the wafer, it is advantageous for rapid heating.

(Flow Control Table)
The film type of the substrate to be processed, the gas flow rate (or flow velocity), the microwave output, and the processing time are stored in advance in a storage unit in table format, and processing is performed under conditions corresponding to the substrate to be processed. Here, by performing control using a control table, it becomes possible to respond to changes due to time (or recipe steps) and changes due to the type of film to be processed. Furthermore, it becomes possible to control the amount of heat buildup by measuring the distribution using multiple IR sensors (or thermo cameras).

Figure 9 shows an example of the substrate processing flow according to this embodiment. Here, an example of a method for modifying (e.g., crystallizing) an amorphous silicon film as a silicon-containing film formed on a substrate as one step in the manufacturing process of a semiconductor device using the above-mentioned substrate processing apparatus will be described along the processing flow shown in Figure 9. In the following description, the operation of each part constituting the substrate processing apparatus is controlled by the control unit described in Figure 4. Here, when the word "wafer" is used, it can mean the wafer itself or a laminate of the wafer and a predetermined layer or film formed on its surface.

First, after the substrate removal step (S801), the substrate loading step (S802) is performed, and the wafers 200 are loaded (boat loaded) into a predetermined processing chamber 201 by opening and closing the gate valve 205. That is, for example, five wafers are loaded into the processing chamber 201 using the low-temperature tweezers 125a-1 and the high-temperature tweezers 125a-2.

(Furnace pressure/temperature adjustment process (S803))
After the wafer 200 has been loaded into the processing chamber 201, the atmosphere in the processing chamber 201 is controlled to a predetermined pressure (for example, 10 to 102,000 Pa). Based on the pressure information detected by the pressure regulator 245, the valve opening of the pressure regulator 244 is feedback-controlled to maintain a predetermined pressure inside the processing chamber 201. The expression "10 to 102,000 Pa" means that the lower and upper limits are included in the range. For example, "10 to 102,000 Pa" means "10 Pa or more and 102,000 Pa or less." The same applies to other numerical ranges. be.

(Inert gas supply step (S804))
When the pressure and temperature in the process chamber 201 are controlled to a predetermined value by the furnace pressure/temperature adjustment step S803, the drive mechanism 267 rotates the shaft 255 to rotate the wafer 200 via the boat 217 on the mounting table 210. At this time, an inert gas such as nitrogen gas is supplied via the gas supply pipe 232 (S804). Furthermore, at this time, the pressure in the process chamber 201 is adjusted to a predetermined value in the range of 10 Pa to 102000 Pa, for example, 101300 Pa to 101650 Pa. Note that the shaft may be rotated during the substrate loading step S402, that is, after the wafer 200 has been loaded into the process chamber 201.

(Preheating step (S805))
Next, when the inside of the processing chamber 201 reaches a predetermined pressure, the microwave oscillator 655 supplies a first microwave into the processing chamber 201 via the above-mentioned components. A preheating process is performed to heat the wafer 200 with the first microwave output (e.g., 3600 W) and the microwave supply ON time (e.g., 150 seconds). This makes it possible to prevent the substrate from warping or cracking by slowing down the temperature rise of the substrate.

(Modification process (S806))
While maintaining the inside of the processing chamber 201 at a predetermined pressure, the microwave generator 655 supplies the second microwave (e.g., 5130 W) into the processing chamber 201 through the above-mentioned components for a predetermined time (e.g., 600 seconds). By supplying the second microwave into the processing chamber 201, the wafer 200 is heated to a temperature of 100° C. or more and 1000° C. or less, preferably 400° C. or more and 900° C. or less, and more preferably 500° C. or more and 700° C. or less. By processing the substrate at such a temperature, the wafer 200 is processed at a temperature at which the wafer 200 efficiently absorbs the microwave, and the speed of the modification process can be improved. In other words, if the wafer is processed at a temperature lower than 100° C. or higher than 1000° C., the surface of the wafer is altered, making it difficult to absorb the microwave, and therefore difficult to heat the wafer. For this reason, it is desirable to perform the substrate processing in the above-mentioned temperature range.

(Substrate unloading process (S807))
After the pressure in the processing chamber 201 is returned to atmospheric pressure, the gate valve 205 is opened to spatially communicate the processing chamber 201 with the transfer chamber 203. The wafer 200 is transferred to the transfer chamber 203 by the high-temperature tweezers 125a-2 of the transfer machine 125 (S807).

(Substrate cooling step (S808))
The heated (i.e., processed) wafer 200 is transferred by the high-temperature tweezers 125a-2 to the cooling chamber 204 by the continuous operation of the transfer device 125b and the transfer device elevator 125c. By -2, for example, five wafers 200 are placed in the cooling chamber 204 and cooled by being left there for a predetermined time (S808).

(Substrate accommodation step (S809))
The wafer 200 cooled in the substrate cooling step S808 is removed from the cooling chamber 204 and transferred to a predetermined pod.

In the above embodiment, the first microwave output is described as 3600W, but the first output is 2000W to 4000W. The advantage of a first output of 2000W to 4000W is that it shortens the time from when the wafer starts to warp until it reaches its maximum and settles down. The disadvantage of a first output lower than 2000W is that it takes too long for the wafer temperature to start to rise. The disadvantage of a first output higher than 4000W is that the wafer temperature rises too quickly, causing the wafer to warp too much, raising the risk of contact with other objects.

In the above embodiment, the second microwaves are described as being 5130W, but the second output is 4000W to 12000W. The advantage of using 4000W to 12000W is that the process wafers can be adjusted to an appropriate temperature for treatment. The disadvantage of using a power lower than 4000W is that a long treatment time is required or insufficient processing may occur. The disadvantage of using a power higher than 12000W is that, depending on the number of wafers being processed at one time, the microwave absorption limit of the wafer may be exceeded, which may result in discharge or plasma generation.

According to the device of this embodiment described above, when the substrate is heated in order to make the temperature distribution across the surface of the semiconductor substrate uniform, gas is supplied from a nozzle to the substrate for a predetermined time while maintaining the substrate at a predetermined temperature, thereby performing modification processing, thereby reducing the temperature difference on the semiconductor substrate, improving the processing quality of the semiconductor substrate and suppressing the occurrence of warping and cracking. Furthermore, it becomes possible to process multiple substrates simultaneously, which also improves productivity.

The above-described embodiment can be modified as appropriate and the effects thereof can be obtained. For example, the above description describes a process for modifying an amorphous silicon film into a polysilicon film as a film mainly composed of silicon, but the present invention is not limited to this. A gas containing at least one of oxygen (O), nitrogen (N), carbon (C), and hydrogen (H) may be supplied to modify a film formed on the surface of the wafer 200. For example, when a hafnium oxide film (HfxOy film) is formed on the wafer 200 as a high dielectric film, the missing oxygen in the hafnium oxide film can be replenished and the characteristics of the high dielectric film can be improved by supplying microwaves while supplying a gas containing oxygen to heat the hafnium oxide film.

Although hafnium oxide film has been described here, the present invention is not limited to this, and can also be suitably applied to oxide films containing metal elements including at least one of aluminum (Al), titanium (Ti), zirconium (Zr), tantalum (Ta), niobium (Nb), lanthanum (La), cerium (Ce), yttrium (Y), barium (Ba), strontium (Sr), calcium (Ca), lead (Pb), molybdenum (Mo), tungsten (W), etc., i.e., when modifying metal-based oxide films. That is, the above-mentioned film formation sequence can be suitably applied to the case of modifying a TiOCN film, a TiOC film, a TiON film, a TiO film, a ZrOCN film, a ZrOC film, a ZrON film, a ZrO film, a HfOCN film, a HfOC film, a HfON film, a HfO film, a TaOCN film, a TaOC film, a TaON film, a TaO film, a NbOCN film, a NbOC film, a NbON film, a NbO film, an AlOCN film, an AlOC film, an AlON film, an AlO film, a MoOCN film, a MoOC film, a MoON film, a MoO film, a WOCN film, a WOC film, a WON film, or a WO film on the wafer 200.

In addition to high-dielectric films, films mainly composed of silicon doped with impurities may be heated. Films mainly composed of silicon include Si-based oxide films such as silicon nitride film (SiN film), silicon oxide film (SiO film), silicon oxycarbide film (SiOC film), silicon oxycarbonitride film (SiOCN film), and silicon oxynitride film (SiON film). The impurities include at least one of bromine (B), carbon (C), nitrogen (N), aluminum (Al), phosphorus (P), gallium (Ga), and arsenic (As).

The resist film may also be based on at least one of methyl methacrylate resin (Polymethyl methacrylate: PMMA), epoxy resin, novolac resin, polyvinyl phenyl resin, etc.

Although the above describes one step in the manufacturing process of a semiconductor device, the present invention is not limited to this and can also be applied to substrate processing techniques such as patterning processes in the manufacturing process of liquid crystal panels, patterning processes in the manufacturing process of solar cells, and patterning processes in the manufacturing process of power devices.

Note that the present disclosure is not limited to the embodiments described above, and further includes various modified examples. For example, the embodiments described above are described in detail to clearly explain the present disclosure, and are not necessarily limited to those having all of the configurations described.

Furthermore, although the above-mentioned configurations, functions, and controllers serving as control units have been described with a focus on examples in which programs are created to realize all or part of them, it goes without saying that all or part of them may be realized in hardware, for example by designing them as integrated circuits. In other words, all or part of the functions of the processing unit may be realized by integrated circuits such as ASICs (Application Specific Integrated Circuits) and FPGAs (Field Programmable Gate Arrays) instead of programs.

100 Substrate processing apparatus 105 Nozzle 200 Wafer (semiconductor substrate)
655 Microwave oscillator (electromagnetic wave source, electromagnetic wave generator)

Claims (15)

a processing chamber for processing a plurality of substrates held by a substrate holder;
an electromagnetic wave generator for supplying electromagnetic waves into the processing chamber;
a gas supply unit that supplies a cooling gas between the plurality of substrates from a plurality of gas supply ports that are provided so as to match the intervals at which the plurality of substrates are held;
a rotation mechanism that rotates the plurality of substrates held by the substrate holder;
A control unit ,
The control unit is configured to be capable of controlling the electromagnetic wave generator and the rotation mechanism so that, when the electromagnetic waves generated by the electromagnetic wave generator are turned off, the amount of cooling gas supplied between the multiple substrates by the gas supply unit is reduced to less than the amount supplied when the electromagnetic waves generated by the electromagnetic wave generator are turned on, or to stop the supply of the cooling gas, and so that the ON/OFF cycle of the electromagnetic waves and the rotation of the multiple substrates are asynchronous . The substrate processing apparatus according to claim 1 , wherein the number of the plurality of gas supply ports is the same as the number of the plurality of substrates. The substrate processing apparatus according to claim 1, wherein the plurality of gas supply ports are open so as to supply the cooling gas in a direction shifted from the center of the substrate toward the edge. The substrate processing apparatus according to claim 1, wherein the flow rate of the cooling gas is 0.2 m/s or more and 40.0 m/s or less. The substrate processing apparatus according to claim 1, wherein the flow rate of the cooling gas is 1 slm or more and 50 slm or less. The substrate processing apparatus according to claim 1, wherein the diameter of the plurality of gas supply ports is 0.2 mm or more and 5.0 mm or less. The substrate processing apparatus according to claim 1, wherein the electromagnetic wave generator is provided on a side wall of the processing chamber. The substrate processing apparatus according to claim 1, wherein the electromagnetic waves are microwaves. The substrate processing apparatus according to claim 1 , wherein the plurality of gas supply ports are provided in a direction in which the plurality of substrates are held by the substrate holding part . a step of loading the substrates into a processing chamber of a substrate processing apparatus, the processing chamber including: a processing chamber for processing a plurality of substrates held by a substrate holder; an electromagnetic wave generator for supplying electromagnetic waves into the processing chamber; a gas supply unit for supplying a cooling gas between the plurality of substrates from a plurality of gas supply ports provided to match the intervals at which the plurality of substrates are held; and a rotation mechanism for rotating the plurality of substrates held by the substrate holder;
processing the substrate;
having
a gas supply unit that supplies a cooling gas between the plurality of substrates to a gas supply unit that is not asynchronous with the rotation of the plurality of substrates when the electromagnetic waves generated by the electromagnetic wave generator are turned on, and a cooling gas supply unit that supplies a cooling gas between the plurality of substrates to a gas supply unit that is not asynchronous with the rotation of the plurality of substrates when the electromagnetic waves generated by the electromagnetic wave generator are turned on, the gas supply unit being configured to supply a cooling gas between the plurality of substrates to a gas supply unit that is not asynchronous with the rotation of the plurality of substrates when the electromagnetic waves generated by the electromagnetic wave generator are turned on . The method for manufacturing a semiconductor device according to claim 10 , wherein in the step of processing the substrate, the cooling gas is supplied in a direction shifted from a center of the substrate toward an edge of the substrate. 11. The method for manufacturing a semiconductor device according to claim 10 , wherein in the step of processing the substrate, a flow velocity of the cooling gas is 0.2 m/s or more and 40.0 m/s or less, or a flow rate of the cooling gas is 1 slm or more and 50 slm or less. a step of loading the substrates into a processing chamber of a substrate processing apparatus, the processing chamber comprising: a processing chamber for processing a plurality of substrates held by a substrate holder; an electromagnetic wave generator for supplying electromagnetic waves into the processing chamber; a gas supply unit for supplying a cooling gas between the plurality of substrates from a plurality of gas supply ports provided to match the intervals at which the plurality of substrates are held; and a rotation mechanism for rotating the plurality of substrates held by the substrate holder;
processing the substrate;
A program for causing the substrate processing apparatus to execute the above,
In the procedure for processing the substrate, when the electromagnetic waves generated by the electromagnetic wave generator are turned off, the amount of cooling gas supplied between the multiple substrates by the gas supply unit is reduced to less than the amount supplied when the electromagnetic waves generated by the electromagnetic wave generator are turned on, or the supply of the cooling gas is stopped, and the program controls the electromagnetic wave generator and the rotation mechanism so that the ON/OFF cycle of the electromagnetic waves and the rotation of the substrate are asynchronous . The program according to claim 13 , wherein in the step of processing the substrate, the cooling gas is supplied in a direction shifted from a center of the substrate toward an edge of the substrate. The program according to claim 13 , wherein in the step of processing the substrate, the flow velocity of the cooling gas is 0.2 m/s or more and 40.0 m/s or less, or the flow rate of the cooling gas is 1 slm or more and 50 slm or less.

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