Substrate processing method, method for manufacturing semiconductor device, program, and substrate processing device

Abstract

Provided is a technique enabling an improvement in film properties.　The substrate processing method comprises the steps of: a) supplying a first raw material to a substrate, b) supplying a first reactant to the substrate in a first amount, c) supplying a second reactant to the substrate in a second amount, d) performing steps a) and b) a predetermined number of times and forming a first layer on the substrate, and e) performing the steps a) and c) a predetermined number of times and forming a second layer on the substrate.

Description

Substrate processing method, semiconductor device manufacturing method, program, and substrate processing apparatus

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

[0002] 2. Description of the Related Art One step in the manufacturing process of a semiconductor device is to form a film on a substrate (see, for example, Japanese Patent Application Laid-Open No. 2003-122998).

[0003] JP 2008-124184 A

[0004] The present disclosure provides techniques that can improve film properties.

[0005] According to one aspect of the present disclosure, there is provided a technique comprising: a) supplying a first source to a substrate; b) supplying a first amount of a first reactant to the substrate; c) supplying a second amount of a second reactant to the substrate; d) performing a) and b) a predetermined number of times to form a first layer on the substrate; and e) performing a) and c) a predetermined number of times to form a second layer on the substrate.

[0006] According to the present disclosure, it is possible to improve the properties of the film.

[0007] Fig. 1 is a longitudinal cross-sectional view showing an outline of a substrate processing apparatus. Fig. 2 is a schematic cross-sectional view taken along line A-A in Fig. 2. Fig. 3 is a schematic configuration diagram of a controller of the substrate processing apparatus, showing a control system of the controller in a block diagram. Fig. 4 is a series of flowcharts including a substrate processing process. Fig. 5 is a flowchart showing the first processing to the modification processing.

[0008] <One Aspect of the Present Disclosure> One aspect of the present disclosure will be described below, mainly with reference to Figures 1 to 5. Note that all drawings used in the following description are schematic, and the dimensional relationships between elements, the ratios of elements, and the like shown in the drawings do not necessarily match those in reality. Furthermore, the dimensional relationships between elements, the ratios of elements, and the like do not necessarily match between multiple drawings.

[0009] (1) Configuration of the Substrate Processing Apparatus The substrate processing apparatus 10 includes a processing furnace 202 provided with a heater 207 as a heating means (heating mechanism, heating system). The heater 207 has a cylindrical shape and is installed vertically by being supported by a heater base (not shown) as a holding plate.

[0010] An outer tube 203 concentrically arranged inside the heater 207 constitutes a processing vessel. The outer tube 203 is made of a heat-resistant material such as quartz or silicon carbide (SiC) and has a cylindrical shape with a closed upper end and an open lower end. A manifold 209 (hereinafter referred to as MF 209) is arranged concentrically below the outer tube 203. The MF 209 is made of a metal such as stainless steel and has a cylindrical shape with open upper and lower ends. An O-ring 220a is provided as a sealing member between the upper end of the MF 209 and the outer tube 203. The MF 209 is supported by a heater base, so that the outer tube 203 is installed vertically.

[0011] An inner tube 204 that constitutes the processing vessel is disposed inside the outer tube 203. The inner tube 204 is made of a heat-resistant material such as quartz or SiC, and is formed in a cylindrical shape with a closed upper end and an open lower end. The processing vessel is mainly constituted by the outer tube 203, the inner tube 204, and the MF 209. A processing chamber 201 is formed in the cylindrical hollow portion of the processing vessel (inside the inner tube 204).

[0012] The processing chamber 201 is configured to accommodate wafers 200 as substrates arranged in multiple stages in the vertical direction in a horizontal position on a boat 217 (described later).

[0013] Nozzles 410, 420, 430, and 440 are provided in the processing chamber 201 so as to penetrate the sidewall of the MF 209 and the inner pipe 204. Gas supply pipes 310, 320, 330, and 340 are connected to the nozzles 410, 420, 430, and 440, respectively. However, the processing furnace 202 of this embodiment is not limited to the above-mentioned configuration.

[0014] Mass flow controllers (MFCs) 312, 322, 332, and 342, which are flow rate controllers (flow rate control parts), are respectively provided in the gas supply pipes 310, 320, 330, and 340, in this order from the upstream side. Also, valves 314, 324, 334, and 344, which are on-off valves, are respectively provided in the gas supply pipes 310, 320, 330, and 340. Gas supply pipes 510, 520, 530, and 540, which supply inert gas, are connected to the downstream sides of the valves 314, 324, 334, and 344 of the gas supply pipes 310, 320, 330, and 340, respectively. The gas supply pipes 510, 520, 530, and 540 are provided with MFCs 512, 522, 532, and 542, which are flow rate controllers (flow rate control parts), and valves 514, 524, 534, and 544, which are on-off valves, in this order from the upstream side.

[0015] Nozzles 410, 420, 430, and 440 are respectively connected to the tip ends of the gas supply pipes 310, 320, 330, and 340. The nozzles 410, 420, 430, and 440 are configured as L-shaped nozzles, and their horizontal portions are provided so as to penetrate the side wall of the MF 209 and the inner pipe 204. The vertical portions of the nozzles 410, 420, 430, and 440 are provided inside the channel-shaped (groove-shaped) pre-chamber 201a, which protrudes radially outward from the inner pipe 204 and extends vertically, and are provided in the pre-chamber 201a along the inner wall of the inner pipe 204 facing upward (upward in the arrangement direction of the wafers 200) along the inner wall of the inner pipe 204.

[0016] The nozzles 410, 420, 430, and 440 are provided extending from the lower region of the processing chamber 201 to the upper region thereof, with multiple gas supply holes 410a, 420a, 430a, and 440a respectively provided at positions facing the wafer 200. This allows processing gas to be supplied to the wafer 200 from the gas supply holes 410a, 420a, 430a, and 440a of the nozzles 410, 420, 430, and 440. The gas supply holes 410a, 420a, 430a, and 440a are provided in multiple locations from the bottom to the top of the inner tube 204, each having the same opening area and arranged at the same opening pitch. However, the gas supply holes 410a, 420a, 430a, and 440a are not limited to the above configuration. For example, the opening area may gradually increase from the bottom to the top of the inner tube 204. This makes it possible to make the flow rates of the gases supplied from the gas supply holes 410a, 420a, 430a, and 440a more uniform.

[0017] The gas supply holes 410a, 420a, 430a, and 440a of the nozzles 410, 420, 430, and 440 are provided at a plurality of positions at a height from the bottom to the top of the boat 217, which will be described later. Therefore, the process gas supplied into the process chamber 201 from the gas supply holes 410a, 420a, 430a, and 440a of the nozzles 410, 420, 430, and 440 is supplied to the entire area of ​​the wafers 200 accommodated in the boat 217 from the bottom to the top. The nozzles 410, 420, 430, and 440 may be provided so as to extend from the lower region to the upper region of the process chamber 201, but are preferably provided so as to extend to near the ceiling of the boat 217.

[0018] A first element-containing gas containing a first element is supplied as a first source material (first process gas) from the gas supply pipe 310 into the process chamber 201 via the MFC 312 , the valve 314 , and the nozzle 410 .

[0019] A second element-containing gas containing a second element is supplied as a second source material (second process gas) from the gas supply pipe 320 into the process chamber 201 via the MFC 322 , the valve 324 , and the nozzle 420 .

[0020] A first reactant (third process gas) is supplied from the gas supply pipe 330 into the process chamber 201 via the MFC 332 , the valve 334 , and the nozzle 430 .

[0021] A second reactant (fourth process gas) is supplied from the gas supply pipe 340 into the process chamber 201 via an MFC 342 , a valve 344 , and a nozzle 440 .

[0022] From the gas supply pipes 510, 520, 530, and 540, an inert gas such as nitrogen (N ２ ) gases are supplied into the processing chamber 201 via MFCs 512, 522, 532, and 542, valves 514, 524, 534, and 544, and nozzles 410, 420, 430, and 440, respectively. ２ An example using gas will be described. As an inert gas, N ２ In addition to the gas, for example, a rare gas such as Ar gas, He gas, Ne gas, or Xe gas may be used.

[0023] The process gas supply system is mainly composed of the gas supply pipes 310, 320, 330, and 340, the MFCs 312, 322, 332, and 342, the valves 314, 324, 334, and 344, and the nozzles 410, 420, 430, and 440. However, only the nozzles 410, 420, 430, and 440 may be considered to be the process gas supply system. The process gas supply system may also be simply referred to as a gas supply system. When the first source material is flowed from the gas supply pipe 310, the first source material supply system (also referred to as a first supply system or a first supply unit) is mainly composed of the gas supply pipe 310, the MFC 312, and the valve 314. However, the nozzle 410 may also be considered to be included in the first source material supply system. Furthermore, when the second raw material is flowed from the gas supply pipe 320, a second raw material supply system (also referred to as a second supply system) is mainly constituted by the gas supply pipe 320, the MFC 322, and the valve 324, but the nozzle 420 may be considered to be included in the second raw material supply system. Furthermore, when the first reactant is flowed from the gas supply pipe 330, a first reactant supply system (also referred to as a third supply system or a second supply unit) is mainly constituted by the gas supply pipe 330, the MFC 332, and the valve 334, but the nozzle 430 may be considered to be included in the first reactant supply system. Furthermore, when the second reactant is flowed from the gas supply pipe 340, a second reactant supply system (also referred to as a fourth supply system or a third supply unit) is mainly constituted by the gas supply pipe 340, the MFC 342, and the valve 344, but the nozzle 440 may be considered to be included in the second reactant supply system. Furthermore, the gas supply pipes 510, 520, 530, and 540, the MFCs 512, 522, 532, and 542, and the valves 514, 524, 534, and 544 mainly constitute an inert gas supply system.

[0024] In this embodiment, gas is supplied via nozzles 410, 420, 430, and 440 arranged in a preliminary chamber 201a in a vertically elongated annular space defined by the inner wall of the inner tube 204 and the ends of the wafers 200. Gas is then ejected into the inner tube 204 from a plurality of gas supply holes 410a, 420a, 430a, and 440a provided in the nozzles 410, 420, 430, and 440 at positions facing the wafers.

[0025] The exhaust hole (exhaust port) 204a is an opening formed in the sidewall of the inner tube 204 at a position facing the nozzles 410, 420, 430, and 440. The opening has, for example, a slit shape. Gas is supplied into the processing chamber 201 from the gas supply holes 410a, 420a, 430a, and 440a of the nozzles 410, 420, 430, and 440 and flows over the surface of the wafer 200. The gas flows through the exhaust hole 204a into the exhaust path 206, which is formed by a gap between the inner tube 204 and the outer tube 203. The gas that flows into the exhaust path 206 then flows into the exhaust pipe 231 and is discharged to the outside of the processing furnace 202.

[0026] The exhaust hole 204a is provided at a position facing the plurality of wafers 200, and gas supplied from the gas supply holes 410a, 420a, 430a, and 440a to the vicinity of the wafers 200 in the processing chamber 201 flows horizontally and then flows into the exhaust path 206 through the exhaust hole 204a. The exhaust hole 204a is not limited to being configured as a slit-shaped through-hole, and may be configured as a plurality of holes.

[0027] The MF 209 is provided with an exhaust pipe 231 that exhausts the atmosphere inside the process chamber 201. The exhaust pipe 231 is connected to, in order from upstream, a pressure sensor 245 serving as a pressure detector (pressure detection unit) that detects the pressure inside the process chamber 201, an APC (Auto Pressure Controller) valve 243, and a pump 246 serving as an exhaust device. The APC valve 243 can exhaust or stop exhausting the atmosphere inside the process chamber 201 by opening and closing the valve while the pump 246 is operating. Furthermore, the pressure inside the process chamber 201 can be adjusted by adjusting the valve opening while the pump 246 is operating. An exhaust system is mainly composed of the exhaust hole 204a, the exhaust path 206, the exhaust pipe 231, the APC valve 243, and the pressure sensor 245. The pump 246 may be included in the exhaust system.

[0028] A seal cap 219 (hereinafter referred to as SC219) is provided below the MF209 as a furnace port cover capable of airtightly closing the lower end opening of the MF209. The SC219 is configured to abut against the lower end of the MF209 from below in the vertical direction. The SC219 is made of a metal such as SUS and is formed in a disk shape. An O-ring 220b is provided on the upper surface of the SC219 as a sealing member that abuts against the lower end of the MF209. A rotation mechanism 267 is installed on the opposite side of the SC219 from the process chamber 201 to rotate a boat 217 that accommodates wafers 200. A rotation shaft 255 of the rotation mechanism 267 is connected to the boat 217 through the SC219. The rotation mechanism 267 is configured to rotate the boat 217 to rotate the wafers 200. The SC 219 is configured to be raised and lowered in the vertical direction by a boat elevator 115 (hereinafter referred to as BE 115) as a lifting mechanism installed vertically outside the outer tube 203. The BE 115 is configured to be able to load and unload the boat 217 into and out of the processing chamber 201 by lifting and lowering the SC 219. The BE 115 is configured as a transfer device (transfer system) that transfers the boat 217 and the wafers 200 accommodated in the boat 217 into and out of the processing chamber 201.

[0029] The boat 217, which serves as a substrate support, is configured to hold a plurality of wafers 200, e.g., 10 to 200 wafers 200, arranged horizontally and spaced apart in the vertical direction. The boat 217 is made of a heat-resistant material such as quartz or SiC. A heat insulating cylinder 218, which is a cylindrical member made of a heat-resistant material such as quartz or SiC, is provided at the bottom of the boat 217. This configuration makes it difficult for heat from the heater 207 to be transmitted to the SC 219. However, this embodiment is not limited to the above-described embodiment. For example, instead of providing the heat insulating cylinder 218 at the bottom of the boat 217, the boat 217 may be configured so that heat insulating plates made of a heat-resistant material such as quartz or SiC are supported in multiple stages in a horizontal position.

[0030] 2, a temperature sensor 263 serving as a temperature detector is installed inside the inner pipe 204, and the amount of power supplied to the heater 207 is adjusted based on temperature information detected by the temperature sensor 263, thereby achieving a desired temperature distribution inside the processing chamber 201. The temperature sensor 263 is configured in an L-shape similar to the nozzles 410, 420, 430, and 440, and is provided along the inner wall of the inner pipe 204.

[0031] 3, the controller 121, which is a control unit (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. An input / output device 122, which is configured as, for example, a touch panel, is connected to the controller 121.

[0032] The storage device 121c is composed of, for example, a flash memory, an HDD (Hard Disk Drive), etc. The storage device 121c readably stores a control program for controlling the operation of the substrate processing apparatus, a process recipe describing the procedures and conditions of a semiconductor device manufacturing method described later, and the like. The process recipe is a combination of processes (steps) in a semiconductor device manufacturing method described later that are executed by the controller 121 to obtain a predetermined result, and functions as a program recorded on a computer-readable recording medium. Hereinafter, the process recipe, control program, etc. are collectively referred to simply as a program. In this specification, the term "program" may refer to a process recipe alone, a control program alone, or a combination of a process recipe and a control program. The RAM 121b is configured as a memory area for temporarily storing programs, data, etc. read by the CPU 121a.

[0033] The I / O port 121d is connected to the above-mentioned MFCs 312, 322, 332, 342, 512, 522, 532, 542, valves 314, 324, 334, 344, 514, 524, 534, 544, pressure sensor 245, APC valve 243, pump 246, heater 207, temperature sensor 263, rotation mechanism 267, BE 115, etc.

[0034] The CPU 121a is configured to read and execute a control program from the storage device 121c, and to read a recipe or the like from the storage device 121c in response to an input of an operation command from the input / output device 122. The CPU 121a is configured to be able to control, in accordance with the contents of the read recipe, the flow rate adjustment operation of various gases by the MFCs 312, 322, 332, 342, 512, 522, 532, and 542, the opening and closing operation of the valves 314, 324, 334, 344, 514, 524, 534, and 544, the opening and closing operation of the APC valve 243 and the pressure adjustment operation by the APC valve 243 based on the pressure sensor 245, the temperature adjustment operation of the heater 207 based on the temperature sensor 263, the start and stop of the pump 246, the rotation and rotation speed adjustment operation of the boat 217 by the rotation mechanism 267, the lifting and lowering operation of the boat 217 by the BE 115, the accommodation operation of the wafers 200 in the boat 217, and the like.

[0035] The controller 121 can be configured by installing the above-mentioned program stored in an external storage device (e.g., a magnetic disk such as a hard disk, an optical disk such as a CD or DVD, or a semiconductor memory such as a flash memory) 123 into a computer. The storage device 121c and the external storage device 123 are configured as computer-readable recording media on which the program is recorded. Hereinafter, these will be collectively referred to simply as recording media. In this specification, the recording medium may include only the storage device 121c, only the external storage device 123, or both. The program (program product) 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.

[0036] (2) Substrate Processing Step (Substrate Processing Method) As one step in the manufacturing process of a semiconductor device, an example of a step of forming a film on a wafer 200 will be described with reference to Fig. 4. This step is performed using the processing furnace 202 of the substrate processing apparatus 10 described above. In the following description, the operation of each part constituting the substrate processing apparatus 10 is controlled by a controller 121.

[0037] The substrate processing process (device manufacturing process) according to this embodiment includes: a) a step of supplying a first source material to the wafer 200; b) a step of supplying a first amount of a first reactant to the wafer 200; c) a step of supplying a second amount of a second reactant to the wafer 200; d) a step of performing a) and b) a predetermined number of times to form a first layer on the wafer 200; and e) a step of performing a) and c) a predetermined number of times to form a second layer on the wafer 200.

[0038] In this specification, the term "wafer" may mean "the wafer itself" or "a laminate of a wafer and a predetermined layer, film, etc. formed on its surface." In this specification, the term "surface of a wafer" may mean "the surface of the wafer itself" or "the surface of a predetermined layer, film, etc. formed on the wafer." In this specification, the term "substrate" is synonymous with the term "wafer."

[0039] (Wafer Loading) When multiple wafers 200 are placed on the boat 217, as shown in FIG. 1, the boat 217 supporting the multiple wafers 200 is lifted by the BE 115 and loaded into the processing chamber 201 of the processing vessel, and is accommodated in the processing vessel.

[0040] (Pressure Regulation and Temperature Regulation) The processing chamber 201, i.e., the space in which the wafer 200 resides, is evacuated by the pump 246 to a desired pressure. 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 (pressure regulation). The pump 246 is kept in a constantly operating state at least until processing of the wafer 200 is completed. The processing chamber 201 is also heated by the heater 207 to a desired temperature. At this time, the amount of power supplied to the heater 207 is feedback-controlled based on temperature information detected by the temperature sensor 263 so that the processing chamber 201 has a desired temperature distribution (temperature regulation). The heating of the processing chamber 201 by the heater 207 continues at least until processing of the wafer 200 is completed. In the process of forming a film on the wafer 200, the wafer 200 is controlled to be maintained at a temperature of 150 to 400°C. In this specification, when a numerical range such as "150 to 400°C" is expressed, it means that the lower limit and the upper limit are included in the range. Thus, for example, "150 to 400°C" means "150°C or higher and 400°C or lower." The same applies to other numerical ranges.

[0041] (Film Formation Process) Subsequently, the film formation process is performed. In the film formation process, a first process, a second process, and a third process are performed as shown in Fig. 4. Note that the third process indicated by the dashed line may or may not be performed.

[0042] (First Treatment) The first treatment includes a step of forming a first element-containing layer and a step of forming a second element-containing layer.

[0043] (First Element-Containing Layer Forming Step) (First Source Material Supply Step) The valve 314 is opened, and the first source material is supplied into the gas supply pipe 310. The first source material, the flow rate of which is adjusted by the MFC 312, is supplied into the processing chamber 201 through the gas supply hole 410a of the nozzle 410, and is exhausted through the exhaust pipe 231.

[0044] At this time, the supply amount of the first raw material is adjusted by adjusting the APC valve 243 and the MFC 312. Examples of processing conditions when supplying the first raw material include: first raw material supply flow rate (excluding dilution gas): 0.1 to 10 g / min, more preferably 0.5 to 5 g / min inert gas (dilution gas) supply flow rate: 100 to 100,000 sccm, more preferably 1,000 to 50,000 sccm first raw material supply time: 10 to 600 seconds, more preferably 30 to 300 seconds inert gas supply flow rate (per gas supply pipe): 0 to 50,000 sccm, more preferably 5,000 to 15,000 sccm

[0045] At this time, the first source material is supplied to the wafer 200. By supplying the first source material to the wafer 200, a material containing the first element is adsorbed onto the wafer 200 (the base film on the surface).

[0046] The first source gas can be a gas containing molecules having a first element and a ligand bonded to the first element. The first element can be a metal element, preferably a transition metal element, more preferably a Group 4 element such as zirconium (Zr), hafnium (Hf), or titanium (Ti). The ligand bonded to the first element can be an organic ligand, preferably a hydrocarbon group containing at least one selected from the group consisting of alkyl groups such as methyl, ethyl, propyl, and butyl, amino groups (at least NH- groups), alkylamino groups, cyclopentadienyl groups, cyclohexadienyl groups, and cycloheptatrienyl groups. More preferably, the first source gas contains the first element, an amine group, and another group.

[0047] The first raw material containing Zr as the first element is, for example, tetrakisethylmethylaminozirconium (Zr[N(CH ３ ) C ２ H ５ ] ４ ), tetrakis(diethylamino)zirconium (Zr[N(C ２ H ５ ) ２ ] ４ ), tetrakisdimethylaminozirconium (Zr[N(CH ３ ) ２ ] ４), Zr(MMP) ４ , Zr(O-tBu) ４ , tris(dimethylamino)cyclopentadienyl zirconium ((C ５ H ５ )Zr[N(CH ３ ) ２ ] ３ As the first source material, one or more of these can be used.

[0048] The first source material containing Hf as the first element is, for example, tetrakisethylmethylaminohafnium (Hf[N(CH ３ ) C ２ H ５ ] ４ ), tetrakisdiethylaminohafnium (Hf[N(C ２ H ５ ) ２ ] ４ ), tetrakisdimethylaminohafnium (Hf[N(CH ３ ) ２ ] ４ ), Hf(O-tBu) ４ , Hf(MMP) ４ , tris(dimethylamino)cyclopentadienyl hafnium ((C ５ H ５ )Hf[N(CH ３ ) ２ ] ３ As the first source material, one or more of these can be used.

[0049] The first raw material containing Ti as the first element is, for example, tetrakisethylmethylaminotitanium (Ti[N(CH ３ ) C ２ H ５ ] ４ ), tetrakis(diethylamino)titanium (Ti[N(C ２ H ５ ) ２ ] ４ ), tetrakisdimethylaminotitanium (Ti[N(CH ３ ) ２ ]４ ), Ti(O-tBu) ４ , Ti(MMP) ４ , tris(dimethylamino)cyclopentadienyltitanium ((C ５ H ５ )Ti[N(CH ３ ) ２ ] ３ As the first source material, one or more of these can be used.

[0050] (Inert Gas Supply (Purge) Step) After a predetermined time has elapsed since the start of the supply of the first source material, the valve 314 is closed to stop the supply of the first source material. At this time, the valves 514, 524, 534, and 544 are opened to flow an inert gas into the gas supply pipes 510, 520, 530, and 540 (purge). That is, the inert gas is supplied into the processing chamber 201.

[0051] At this time, the APC valve 243 is adjusted to set the pressure inside the processing chamber 201 within a range of, for example, 1 to 3990 Pa. The supply flow rates of the inert gases controlled by the MFCs 512, 522, 532, and 542 are set within a range of, for example, 0.1 to 30 slm, respectively.

[0052] (Exhaust (Purge) Process) After a predetermined time has elapsed since the start of the supply of the inert gas, the valves 514, 524, 534, and 544 are closed to stop the supply of the inert gas. At this time, the APC valve 243 of the exhaust pipe 231 is opened, and the processing chamber 201 is evacuated to a vacuum by the pump 246. As a result, residual gas is removed from above the wafer 200, and gases and reaction by-products remaining in the processing chamber 201 are expelled from the processing chamber 201. This removes residual gas from above the wafer 200, and reduces the amounts of the first source material and decomposition products remaining in the processing chamber 201. At this time, the time for evacuating the processing chamber 201 is set to, for example, a time within a range of 0.1 to 30 seconds.

[0053] In the purging step, at least one of an inert gas supplying step and an exhausting step is performed.

[0054] (First reactant supply process) Subsequently, the valve 334 is opened to allow the first reactant to flow into the gas supply pipe 330. The first reactant has a flow rate adjusted by the MFC 332, is supplied into the processing chamber 201 through the gas supply hole 430a of the nozzle 430, and is exhausted from the exhaust pipe 231.

[0055] At this time, the APC valve 243 and the MFC 332 are adjusted to adjust the supply amount of the first reactant to a first amount. The processing conditions for supplying the first reactant include: First reactant supply flow rate: 100 to 100,000 sccm, more preferably 1,000 to 10,000 sccm. It may also be 0.1 to 10 g / min, more preferably 0.2 to 5 g / min. Supply time: 10 to 600 seconds, more preferably 30 to 300 seconds. Inert gas supply flow rate (per gas supply pipe): 0 to 50,000 sccm, more preferably 5,000 to 15,000 sccm.

[0056] At this time, a first reactant is supplied to the wafer 200. Here, for example, an oxidizing agent (oxidizing gas) can be used as the first reactant. For example, a gas containing oxygen (O) and a gas containing O and hydrogen (H) can be used as the oxidizing agent. For example, water vapor (H ２ O gas), hydrogen peroxide (H ２ O ２ ) gas, hydrogen (H ２ ) gas + oxygen (O ２ ) Gas, H ２ Gas + ozone (O ３ ) gas, etc. can be used. As the gas containing O, for example, O ２ Gas, O ３ Gases, etc. can be used. As the oxidizing agent, one or more of these can be used. ２ Gas + O ２ In the case of a combination of two gases, such as "gas," ２ Gas and O ２When supplying a mixed gas, the two gases may be mixed (premixed) in a supply pipe and then supplied into the processing chamber 201, or the two gases may be supplied separately from different supply pipes into the processing chamber 201 and then mixed (postmixed) in the processing chamber 201. ３ For example, O ２ Oxygen can be generated from the gas by an ozonizer. Therefore, the nozzle from the ozonizer ２ and O ３ The gas thus produced contains O ３ is supplied to the processing chamber and the wafer 200. Specifically, the oxidizing agent supply nozzle is ２ Gas + O ３ Other nozzles may provide inert gas, and the supply of inert gas may be ３ When the oxidizing agent supply nozzle does not supply both the oxidizing agent and the inert gas, the oxidizing agent supply nozzle and other nozzles can prevent O 2 from entering the processing vessel and the wafer 200. ３ , O ２ , and an inert gas is supplied. Note that the term "agent" used in this disclosure includes at least one of a gaseous substance and a liquid substance. A liquid substance includes a mist-like substance. That is, a film-forming agent, a modifying agent, and an etching agent may contain a gaseous substance, a liquid substance such as a mist-like substance, or both.

[0057] (Inert Gas Supply Process) After a predetermined time has elapsed since the start of the supply of the first reactant, the valve 334 is closed to stop the supply of the first reactant. At this time, the valves 514, 524, 534, and 544 are opened to allow the inert gas to flow into the gas supply pipes 510, 520, 530, and 540. That is, the inert gas is supplied into the processing chamber 201.

[0058] At this time, the APC valve 243 is adjusted to set the pressure inside the processing chamber 201 within a range of, for example, 1 to 3990 Pa. The supply flow rates of the inert gases controlled by the MFCs 512, 522, 532, and 542 are set within a range of, for example, 0.1 to 30 slm. The time for which the inert gas is supplied to the wafers 200 is set within a range of, for example, 0.1 to 30 seconds.

[0059] At this time, an inert gas is supplied into the processing chamber 201. This makes it possible to reduce the first reactant and reaction by-products remaining in the processing chamber 201 without reacting or after contributing to film formation.

[0060] (Exhaust Process) After a predetermined time has elapsed since the start of the supply of the inert gas, the valves 514, 524, 534, and 544 are closed to stop the supply of the inert gas. At this time, the APC valve 243 of the exhaust pipe 231 is opened, and the inside of the processing chamber 201 is evacuated by the pump 246. This removes residual gas from above the wafer 200, and the first reactant and reaction by-products remaining in the processing chamber 201, which have not reacted or have contributed to film formation, are removed from the processing chamber 201. At this time, the time for evacuating the inside of the processing chamber 201 is set to, for example, a time within a range of 0.1 to 30 seconds.

[0061] (Predetermined number of times 1) By performing the above-mentioned first raw material supply process to exhaust process in sequence a predetermined number of times (A times, where A is 1 or an integer greater than or equal to 2), a first first element-containing layer of a predetermined thickness is formed on wafer 200.

[0062] (Step of forming second element-containing layer) (Step of supplying second raw material) The valve 324 is opened, and the second raw material is supplied into the gas supply pipe 320. The second raw material, the flow rate of which is adjusted by the MFC 322, is supplied into the processing chamber 201 through the gas supply hole 420a of the nozzle 420, and is exhausted through the exhaust pipe 231.

[0063] At this time, the supply amount of the second raw material is adjusted by adjusting the APC valve 243 or the MFC 322. Examples of processing conditions when supplying the second raw material include: second raw material supply flow rate (excluding dilution gas): 0.1 to 10 g / min, more preferably 0.5 to 5 g / min inert gas (dilution gas) supply flow rate: 100 to 100,000 sccm, more preferably 1,000 to 50,000 sccm second raw material supply time: 10 to 600 seconds, more preferably 30 to 300 seconds inert gas supply flow rate (per gas supply pipe): 0 to 50,000 sccm, more preferably 5,000 to 15,000 sccm

[0064] At this time, the second source material is supplied to the wafer 200. By supplying the second source material to the wafer 200, a material containing the second element is adsorbed onto the wafer 200 (underlying film on the surface).

[0065] The second source material can be a gas containing molecules having a second element and a ligand bonded to the second element. The second element can be the same as the first element or a different element, preferably a different element. Specific materials for the second source material can be the materials described above as the first source material.

[0066] (Inert Gas Supply Process) After a predetermined time has elapsed since the start of the supply of the second source material, the valve 324 is closed to stop the supply of the second source material. At this time, the valves 514, 524, 534, and 544 are opened to flow an inert gas into the gas supply pipes 510, 520, 530, and 540 (purging). That is, the inert gas is supplied into the processing chamber 201.

[0067] At this time, the APC valve 243 is adjusted to set the pressure inside the processing chamber 201 within a range of, for example, 1 to 3990 Pa. The supply flow rates of the inert gases controlled by the MFCs 512, 522, 532, and 542 are set within a range of, for example, 0.1 to 30 slm, respectively.

[0068] (Exhaust Process) After a predetermined time has elapsed since the start of the supply of inert gas, the valves 514, 524, 534, and 544 are closed to stop the supply of inert gas. At this time, the APC valve 243 of the exhaust pipe 231 is opened, and the processing chamber 201 is evacuated to a vacuum using the pump 246. As a result, residual gas is removed from above the wafer 200, and gases and reaction by-products remaining in the processing chamber 201 are expelled from the processing chamber 201. This removes residual gas from above the wafer 200, thereby reducing the amount of the second source material and decomposition products remaining in the processing chamber 201. The time required for evacuating the processing chamber 201 is, for example, within a range of 0.1 to 30 seconds.

[0069] (First reactant supplying step) Subsequently, the first reactant supplying step is performed in the same manner as described above. The supplying conditions of the first reactant in the second element-containing layer forming step can be set similarly to the supplying conditions of the first reactant in the first element-containing layer forming step.

[0070] (Inert Gas Supplying Step) After a predetermined time has elapsed since the start of the supply of the first reactant, the inert gas supplying step is performed in the same manner as described above.

[0071] (Exhaust Step) After a predetermined time has elapsed since the start of the supply of the inert gas, the exhaust step is carried out in the same manner as described above.

[0072] (Predetermined number of times 2) By performing the above-mentioned second raw material supply process to exhaust process in sequence a predetermined number of times (B times, where B is 1 or an integer greater than or equal to 2), a first second element-containing layer of a predetermined thickness is formed on the wafer 200.

[0073] (Predetermined Number of Times 3) The above-described first element-containing layer forming process (forming the first first element-containing layer) and second element-containing layer forming process (forming the first second element-containing layer) are sequentially performed a predetermined number of times (C times, where C is 1 or an integer equal to or greater than 1), thereby stacking a first first element-containing layer and a first second element-containing layer on the wafer 200. This stacked structure is called the first layer. The first layer is a layer that can be crystallized by a modification process, which will be described later.

[0074] (Second Treatment) Next, the second treatment is performed. As shown in Fig. 4, the second treatment is similar to the first treatment, but differs in that the supply step of the first reactant is replaced by a supply step of the second reactant. Below, the supply step of the reactant different from that of the first treatment (the second reactant supply step) will be described in detail, and a detailed description of the similar steps will be omitted.

[0075] (First element-containing layer formation process) The first element-containing layer formation process in the second process is performed in a flow in which the first reactant supply process in the first element-containing layer formation process in the first process is replaced with a second reactant supply process.

[0076] (Purge Step) At least one of the inert gas supply step and the evacuation step is carried out in the same manner as described above.

[0077] (Second Reactant Supply Process) The valve 344 is opened, and the second reactant is supplied into the gas supply pipe 340. The flow rate of the second reactant is adjusted by the MFC 342, and the second reactant is supplied into the processing chamber 201 through the gas supply hole 440a of the nozzle 440 and exhausted through the exhaust pipe 231.

[0078] At this time, the APC valve 243 and the MFC 342 are adjusted to adjust the supply amount of the second reactant to a second amount. The processing conditions for supplying the second reactant include: Second reactant supply flow rate: 100 to 100,000 sccm, more preferably 1,000 to 10,000 sccm. It may also be 0.01 to 10 g / min, more preferably 0.1 to 2 g / min. Supply time: 10 to 600 seconds, more preferably 30 to 300 seconds. Inert gas supply flow rate (per gas supply pipe): 0 to 50,000 sccm, more preferably 5,000 to 15,000 sccm.

[0079] The oxidizing power of the second reactant is preferably set to be different from that of the first reactant, i.e., the supply conditions (supply amount, gas type) of the second reactant are preferably set so that the oxidizing power of the second reactant is smaller (weaker) than that of the first reactant.

[0080] For example, when the material (gas type) of the first reactant and the material of the second reactant are the same, the second amount, which is the supply amount of the second reactant, is set to be different from the first amount, which is the supply amount of the first reactant. Specifically, the second amount, which is the supply amount of the second reactant, is set to be smaller than the first amount, which is the supply amount of the first reactant. Here, the supply amount is adjusted by controlling at least one of the supply flow rate and the supply time. Specifically, the supply flow rate of the second reactant is set to be smaller than the supply flow rate of the first reactant. Furthermore, the supply time of the second reactant is set to be shorter than the supply time of the first reactant. Note that the partial pressure of the second reactant may be set to be smaller than the partial pressure of the first reactant.

[0081] The oxidizing power may be adjusted by making the material of the first reactant different from the material of the second reactant. For example, in the oxidizing agent of the present disclosure, ３ Gas containing H ２ O ２ The gas and the activated gas of the present disclosure have relatively stronger oxidizing power than other gases of the present disclosure. For example, O ３ , H ２ O ２ , H ２ +O ２ and activated gases, and O ２ , H ２ O, H ２ +O ２ By using at least one of the above, the oxidizing power of the second reactant can be made weaker than the oxidizing power of the first reactant.

[0082] The oxidizing power may be adjusted by combining the materials and the supply conditions.

[0083] (Purge Step) At least one of the inert gas supply step and the evacuation step is carried out in the same manner as described above.

[0084] (Predetermined number of times 1) The processes including the second reactant supply process described above are performed in sequence a predetermined number of times (D times, where D is an integer of 1 or 2 or more) to form a second first element-containing layer of a predetermined thickness on wafer 200.

[0085] (Step of forming second element-containing layer) The step of forming the second element-containing layer in the second treatment is carried out by replacing the step of supplying the first reactant in the step of forming the second element-containing layer in the first treatment with the step of supplying the second reactant described above.

[0086] (Predetermined number of times 2) The above-mentioned processes including the second reactant supply process are sequentially performed a predetermined number of times (E times, where E is an integer of 1 or 2 or more) to form a second second element-containing layer of a predetermined thickness on wafer 200.

[0087] (Predetermined Number of Times 3) In the second process, the first element-containing layer formation process (formation of a second first element-containing layer) and the second element-containing layer formation process (formation of a second second element-containing layer) are sequentially performed a predetermined number of times (F times, where F is an integer of 1 or greater), thereby stacking a second first element-containing layer and a second second element-containing layer on the wafer 200. This stacked structure is called the second layer. Here, the second layer is formed using a second reactant, so that the amount of oxygen contained in the second layer is less than the amount of oxygen contained in the first layer. The second layer is a layer that can contain amorphous matter through a modification process described below.

[0088] (Third Process) Subsequently, a third process may be performed. The flow and various conditions of the third process are set to be different from those of the second process. Furthermore, the flow and various conditions of the third process may be the same as those of the first process, or may be appropriately different.

[0089] In this manner, a process of forming a film in which the first layer and the second layer are stacked on the wafer 200 is carried out.

[0090] In a preferred embodiment of the present disclosure, a gas containing Hf can be used as the first source material, and a gas containing Zr can be used as the second source material. By forming an oxide film containing Hf and Zr in this manner, a film of a ferroelectric material with an extremely high dielectric constant can be formed.

[0091] The first and second layers each form an oxide film containing Hf and Zr. However, as described above, due to the relationship between the oxidizing power of the first reactant and the oxidizing power of the second reactant, the amount of oxygen contained in the second layer is less than the amount of oxygen contained in the first layer. The ratio of the first element to the second element contained in the first layer is close to the ratio of the first element to the second element contained in the second layer. In other words, the ratio of the first element to the second element is approximately the same in the first and second layers. Based on this relationship, the second layer can also be referred to as an oxygen-poor layer relative to the first layer. The second layer can also be referred to as a layer that is more oxygen-deficient than the first layer. Conversely, the first layer can also be referred to as an oxygen-rich layer relative to the second layer. Furthermore, while the first layer has a composition close to the stoichiometric composition, the second layer can also be referred to as an oxygen-poor layer relative to the stoichiometric composition.

[0092] The first process (third process) described above can be expressed by the following sequence (A). The second process can be expressed by the following sequence (B). The first process (third process) may be modified as shown in the following sequences (C) and (D). The second process may be modified as shown in the following sequences (E) and (F). In the following description, purging is omitted. The sequence may be configured so that purging is omitted. (A) [(First raw material supply → First reactant supply) × A → (Second raw material supply → First reactant supply) × B] × C (B) [(First raw material supply → Second reactant supply) × D → (Second raw material supply → Second reactant supply) × E] × F (C) (First raw material supply → First reactant supply → Second raw material supply) × C (D) (First raw material supply → Second reactant supply → First reactant supply) × C (E) (First raw material supply → Second reactant supply → Second raw material supply) × F (F) (First raw material supply → Second reactant supply → Second raw material supply) × F

[0093] (Purge and Return to Atmospheric Pressure) An inert gas is supplied into the processing chamber 201 from each of the gas supply pipes 510 to 540 and exhausted from the exhaust pipe 231. The inert gas acts as a purge gas, thereby purging the processing chamber 201 with the inert gas and removing gases and reaction by-products remaining in the processing chamber 201 from the processing chamber 201. Thereafter, the atmosphere in the processing chamber 201 is replaced with the inert gas, and the pressure in the processing chamber 201 is returned to atmospheric pressure.

[0094] (Wafer Unloading) Thereafter, the SC 219 is lowered by the BE 115 to open the lower end of the outer tube 203. Then, the processed wafers 200 supported by the boat 217 are unloaded from the lower end of the outer tube 203 to the outside of the outer tube 203. Thereafter, the processed wafers 200 are removed from the boat 217.

[0095] 5, a modification process may be performed on the wafer 200 on which the first and second layers have been formed. The modification process may be performed in the same substrate processing apparatus 10 following the first process, second process, and (third process) described above. Furthermore, after the wafer is unloaded, the wafer 200 may be transferred to a substrate processing apparatus 10 different from the substrate processing apparatus 10 that performed the first process, second process, and (third process) described above, and the modification process may be performed thereon.

[0096] The modification process can be, for example, a heat treatment that heats the wafer 200 or a plasma treatment. If the film formed on the wafer 200 is a dielectric (particularly a ferroelectric), a heat treatment (annealing) can be performed. The heat treatment involves heating the wafer 200 to a temperature higher than that used in the film formation process. For example, the wafer 200 is heated to 350°C to 800°C for the heat treatment. The modification process crystallizes the first layer and modifies the second layer into a layer containing amorphous.

[0097] (3) Effects of This Aspect This aspect can achieve one or more of the following effects. (a) By reducing the amount of oxygen contained in the second layer compared to the amount of oxygen contained in the first layer, when a modification process (e.g., heat treatment) is performed, the first layer can be crystallized, and the second layer can become a layer containing amorphous. (b) When a dielectric layer is crystallized, the dielectric constant of the dielectric can be improved. In particular, in a ferroelectric, the properties of the ferroelectric can be expressed. However, there may be a problem of increased leakage current due to crystal grain boundaries. In the present disclosure, a structure is formed in which a crystallized first layer and a second layer containing amorphous are stacked. The number of grain boundaries contained in such a second layer is smaller than that of the first layer. As a result, even if a path that could generate leakage current exists in the first layer, the second layer can block (shut off) the path that could generate leakage current. Therefore, leakage current can be suppressed.

[0098] (4) Other Aspects The above describes specific aspects of the present disclosure. However, the present disclosure is not limited to the above aspects and can be modified in various ways without departing from the spirit and scope of the present disclosure.

[0099] In the above embodiment, an oxidizing agent is used as the first reactant and the second reactant. However, the present disclosure is not limited to this. When forming a film of a simple metal instead of an oxide film on the wafer 200, a reducing agent can be used. Examples of the reducing agent include H ２ Gas, deuterium (D ２ ) gas, etc. Also, when forming a nitride film, a nitriding agent may be used. As the nitriding agent, a gas containing nitrogen may be used. Specifically, NH ３ Gas, N ２ H ４ Gas, N ２ H ２ At least one or more of the gases disclosed herein can be used. The nitriding agent, reducing agent, and oxidizing agent can each be an activated gas of at least one or more of the gases disclosed herein.

[0100] It is preferable that process recipes (programs describing processing procedures, processing conditions, etc.) used to form these various thin films are individually prepared (prepared in multiple numbers) depending on the content of substrate processing (such as the type, composition ratio, film quality, film thickness, processing procedure, and processing conditions of the thin film to be formed). Then, when starting substrate processing, it is preferable to appropriately select an appropriate process recipe from the multiple process recipes depending on the content of substrate processing. Specifically, it is preferable that multiple process recipes (program products) individually prepared depending on the content of substrate processing are pre-stored (installed) in the storage device 121c of the substrate processing apparatus via an electric communication line or a recording medium (external storage device 123) on which the process recipes are recorded. Then, when starting substrate processing, it is preferable that the CPU 121a of the substrate processing apparatus appropriately selects an appropriate process recipe from the multiple process recipes stored in the storage device 121c depending on the content of substrate processing. This configuration makes it possible to versatility and reproducibility in forming thin films of various film types, composition ratios, film qualities, and film thicknesses using a single substrate processing apparatus. Furthermore, the operational burden on the operator (such as the burden of inputting processing procedures and processing conditions) can be reduced, and substrate processing can be started promptly while avoiding operational errors.

[0101] The present disclosure can also be realized, for example, by changing the process recipe of an existing substrate processing apparatus. When changing the process recipe, the process recipe according to the present disclosure can be installed in the existing substrate processing apparatus via an electric communication line or a recording medium on which the process recipe is recorded, or the process recipe itself can be changed to the process recipe according to the present disclosure by operating an input / output device of the existing substrate processing apparatus.

[0102] Furthermore, the present disclosure can be used, for example, in the word line portion of a NAND flash memory or DRAM having a three-dimensional structure.

[0103] In the above-described embodiments and modifications, an example of forming a film using a batch-type substrate processing apparatus that processes multiple wafers 200 at a time has been described. The present disclosure is not limited to the above-described embodiments and can be suitably applied, for example, to a case where a film is formed using a single-wafer substrate processing apparatus that processes one or several wafers 200 at a time. In the above-described embodiments, an example of forming a film using a substrate processing apparatus having a hot-wall processing furnace has been described. The present disclosure is not limited to the above-described embodiments and can be suitably applied to a case where a film is formed using a substrate processing apparatus having a cold-wall processing furnace.

[0104] In the above-described embodiment, the processing sequence is performed in the same processing chamber of the same processing apparatus (in-situ). The present disclosure is not limited to the above-described embodiment, and for example, one step and another step of the processing sequence may be performed in different processing chambers of different processing apparatuses (ex-situ), or may be performed in different processing chambers of the same processing apparatus.

[0105] When using these substrate processing apparatuses, each process can be performed using the same processing procedures and conditions as in the above-described embodiments and modifications, and the same effects as in the above-described embodiments and modifications can be obtained.

[0106] The above-described embodiments and modifications may be used in combination as appropriate. The processing procedures and processing conditions in such a case may be the same as those of the above-described embodiments and modifications, for example.

[0107] 200 wafers (substrates)

Claims

1. A substrate processing method comprising: a) supplying a first source to a substrate; b) supplying a first amount of a first reactant to the substrate; c) supplying a second amount of a second reactant to the substrate; d) performing a) and b) a predetermined number of times to form a first layer on the substrate; and e) performing a) and c) a predetermined number of times to form a second layer on the substrate.

2. The substrate processing method of claim 1, wherein the first amount and the second amount are different amounts.

3. The substrate processing method according to claim 1, wherein the second amount is less than the first amount.

4. The substrate processing method according to claim 1, further comprising the step of performing steps d) and e) a predetermined number of times to stack the first layer and the second layer.

5. The substrate processing method according to claim 1, further comprising the step of: f) supplying a second source material to the substrate; in d), a), b) and f) are performed a predetermined number of times; and in e), a), c) and f) are performed a predetermined number of times.

6. The substrate processing method according to claim 5, wherein the first source material contains a first element, the second source material contains a second element, and the ratio of the first element to the second element contained in the first layer and the ratio of the first element to the second element contained in the second layer are close to each other.

7. The substrate processing method according to claim 1, further comprising the step of: g) modifying the first layer and the second layer.

8. The substrate processing method according to claim 7, wherein in step g), the first layer is crystallized and the second layer is modified to a layer containing amorphous.

9. A substrate processing method according to claim 7, wherein the first layer is a layer that can be crystallized by modification, and the second layer is a layer that can contain an amorphous phase by said modification.

10. The substrate processing method according to claim 7, wherein the modification is a heat treatment.

11. The substrate processing method according to claim 1, wherein the oxidizing power of the first reactant and the oxidizing power of the second reactant are different.

12. The substrate processing method according to claim 1, wherein the oxidizing power of the second reactant is weaker than the oxidizing power of the first reactant.

13. The substrate processing method according to claim 1, wherein the supply amount of the first reactant and the supply amount of the second reactant are different.

14. The substrate processing method according to claim 1, wherein the supply amount of the second reactant is less than the supply amount of the first reactant.

15. The substrate processing method according to claim 1, wherein the partial pressure of the second reactant is lower than the partial pressure of the first reactant.

16. The substrate processing method according to claim 1, wherein the supply flow rate of the second reactant is lower than the supply flow rate of the first reactant.

17. The substrate processing method of claim 1, wherein the first reactant and the second reactant are different materials.

18. A method for manufacturing a semiconductor device, comprising: a) supplying a first raw material to a substrate; b) supplying a first amount of a first reactant to the substrate; c) supplying a second amount of a second reactant to the substrate; d) performing a) and b) a predetermined number of times to form a first layer on the substrate; and e) performing a) and c) a predetermined number of times to form a second layer on the substrate.

19. A program that causes a substrate processing apparatus to execute, via a computer, the following steps: a) supplying a first raw material to a substrate; b) supplying a first amount of a first reactant to the substrate; c) supplying a second amount of a second reactant to the substrate; d) performing steps a) and b) a predetermined number of times to form a first layer on the substrate; and e) performing steps a) and c) a predetermined number of times to form a second layer on the substrate.

20. A substrate processing apparatus comprising: a first supply unit that supplies a first raw material to a substrate; a second supply unit that supplies a first reactant to the substrate; a third supply unit that supplies a second reactant to the substrate; and a control unit configured to be able to control the first supply unit, the second supply unit, and the third supply unit to perform the following processes: a) a process of supplying the first raw material to the substrate; b) a process of supplying the first reactant to the substrate in a first amount; c) a process of supplying the second reactant to the substrate in a second amount; d) a process of performing a) and b) a predetermined number of times to form a first layer on the substrate; and e) a process of performing a) and c) a predetermined number of times to form a second layer on the substrate.

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