Method for processing substrate, method for manufacturing semiconductor device, program and substrate processing apparatus

Abstract

To provide a technology that can improve property of a film to be formed on a substrate.SOLUTION: A method for processing a substrate includes the steps of: (a) supplying a promoter that promotes adsorption of a modifier containing an organic ligand and is not reducible to a substrate; (b) supplying the modifier to the substrate; and (c) forming a film on the substrate after (a) and (b).SELECTED DRAWING: Figure 4

Description

[Technical field]

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

[0002] 2. Description of the Related Art As one step in the manufacturing process of a semiconductor device, a process of forming a metal-containing film on a substrate is sometimes performed (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2022-50996 Summary of the Invention [Problem to be solved by the invention]

[0004] When a film is formed on a substrate, the continuity of the film may be reduced, resulting in deterioration of the properties of the film formed on the substrate.

[0005] The present disclosure provides a technique capable of improving the properties of a film formed on a substrate. [Means for solving the problem]

[0006] According to one aspect of the present disclosure, (a) providing a non-reducing promoter to the substrate that promotes adsorption of the modifier comprising an organic ligand; (b) applying the modifier to the substrate; (c) after performing (a) and (b), forming a film on the substrate; The present invention provides a technique having the following features: Effect of the Invention

[0007] According to the present disclosure, it is possible to improve the characteristics of a film formed on a substrate. [Brief description of the drawings]

[0008] [Figure 1] 1 is a schematic vertical cross-sectional view of a vertical processing furnace of a substrate processing apparatus according to an embodiment of the present disclosure. [Diagram 2] 2 is a schematic cross-sectional view taken along line AA in FIG. 1. [Diagram 3] FIG. 2 is a schematic configuration diagram of a controller of a substrate processing apparatus according to an embodiment of the present disclosure, showing a control system of the controller in a block diagram. [Figure 4] 1A to 1C are diagrams illustrating a substrate processing sequence according to one embodiment of the present disclosure. [Diagram 5] FIG. 13 is a top view illustrating a modified example of the substrate processing apparatus according to the embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, one embodiment of the present disclosure will be described mainly with reference to Figures 1 to 4. Note that all of the drawings used in the following description are schematic, and the dimensional relationships of the elements, the ratios of the elements, etc. shown in the drawings do not necessarily match those in reality. Furthermore, the dimensional relationships of the elements, the ratios of the elements, etc. between multiple drawings do not necessarily match.

[0010] (1) Configuration of the substrate processing device 1, the process furnace 202 has a heater 207 as a heating system (temperature adjustment unit). The heater 207 has a cylindrical shape. The heater 207 also functions as an activation mechanism (excitation unit) that activates (excites) gas by heat.

[0011] A reaction tube 203 is disposed concentrically with the heater 207 inside the heater 207. The reaction tube 203 is made of a heat-resistant material such as quartz (SiO2) or silicon carbide (SiC) and is formed in a cylindrical shape with a closed upper end and an open lower end. A manifold 209 is disposed concentrically with the reaction tube 203 below the reaction tube 203. The manifold 209 is made of a metal such as stainless steel (SUS) and is formed in a cylindrical shape with an open upper end and a closed lower end. The upper end of the manifold 209 engages with the lower end of the reaction tube 203 and is configured to support the reaction tube 203. An O-ring 220a is provided between the manifold 209 and the reaction tube 203 as a seal member. The reaction tube 203 is installed vertically like the heater 207. The reaction tube 203 and the manifold 209 mainly constitute a processing vessel (reaction vessel). A processing chamber 201 is formed in a cylindrical hollow portion of the processing vessel. The processing chamber 201 is configured to be capable of accommodating a plurality of wafers 200 as substrates.

[0012] Nozzles 249a and 249b are provided in the processing chamber 201 so as to penetrate a sidewall of the manifold 209. Gas supply pipes (pipes) 232a and 232b are connected to the nozzles 249a and 249b, respectively.

[0013] Gas supply pipes 232a and 232b are provided with mass flow controllers (MFCs) 241a and 241b, which are flow rate controllers (flow rate control units), and valves 243a and 243b, which are on-off valves, in order from the upstream side. Gas supply pipes 232c and 232e are connected to the gas supply pipe 232a downstream of the valve 243a. Gas supply pipes 232c and 232e are provided with MFCs 241c and 241e and valves 243c and 243e, in order from the upstream side. Gas supply pipes 232d and 232f are connected to the gas supply pipe 232b downstream of the valve 243b. Gas supply pipes 232d and 232f are provided with MFCs 241d and 241f and valves 243d and 243f, in order from the upstream side.

[0014] 2, the nozzles 249a and 249b are provided in a circular space between the inner wall of the reaction tube 203 and the wafers 200 in a plan view, along the inner wall of the reaction tube 203 from the lower part to the upper part, so as to rise upward in the loading direction of the wafers 200. Gas supply holes 250a and 250b for supplying gas are provided on the side of the nozzles 249a and 249b, respectively. The gas supply holes 250a and 250b are each opened to face the center of the reaction tube 203, so that gas can be supplied toward the wafers 200. A plurality of gas supply holes 250a and 250b are provided from the lower part to the upper part of the reaction tube 203.

[0015] A source gas containing a halogen element is supplied from the gas supply pipe 232a into the processing chamber 201 via the MFC 241a, the valve 243a, and the nozzle 249a.

[0016] A reactive gas containing hydrogen elements is supplied from the gas supply pipe 232b into the processing chamber 201 via the MFC 241b, the valve 243b, and the nozzle 249b.

[0017] From the gas supply pipe 232c, a promoter that promotes adsorption of the modifying agent is supplied through the MFC 241c, the valve 243c, and the nozzle 249a into the processing chamber 201. As the promoter, a promoter with no reducing properties is used.

[0018] The term "agent" used in this specification includes at least one of a gaseous substance and a liquid substance. A liquid substance includes a mist-like substance. In other words, the modifier and accelerator may contain a gaseous substance, may contain a liquid substance such as a mist-like substance, or may contain both.

[0019] A modifying agent containing an organic ligand is supplied from the gas supply pipe 232d into the processing chamber 201 via the MFC 241d, the valve 243d, and the nozzle 249b.

[0020] An inert gas is supplied from the gas supply pipes 232e and 232f into the processing chamber 201 via the MFCs 241e and 241f, the valves 243e and 243f, the gas supply pipes 232a and 232b, and the nozzles 249a and 249b.

[0021] A raw material gas supply system is mainly composed of the gas supply pipe 232a, the MFC 241a, and the valve 243a. A reactive gas supply system is mainly composed of the gas supply pipe 232b, the MFC 241b, and the valve 243b. The raw material gas supply system and the reactive gas supply system may be collectively referred to as a gas supply system. A promoter supply system as a first gas supply system is mainly composed of the gas supply pipe 232c, the MFC 241c, and the valve 243c. A modifying agent supply system as a second gas supply system is mainly composed of the gas supply pipe 232d, the MFC 241d, and the valve 243d. An inert gas supply system is mainly composed of the gas supply pipes 232e, 232f, the MFCs 241e, 241f, and the valves 243e, 243f. The promoter supply system, the modifying agent supply system, and the inert gas supply system may be included in the gas supply system.

[0022] Any or all of the various supply systems described above may be configured as an integrated supply system 248 in which the valves 243a-243f, MFCs 241a-241f, etc. are integrated. The integrated supply system 248 is connected to the gas supply pipes 232a-232f, respectively, and is configured so that the supply operation of various gases into the gas supply pipes 232a-232f, i.e., the opening and closing operation of the valves 243a-243f and the flow rate adjustment operation by the MFCs 241a-241f, etc., are controlled by a controller 121, which will be described later. The integrated supply system 248 is configured as an integrated or separate type integrated unit, and can be attached and detached to and from the gas supply pipes 232a-232f, etc., in units of integrated units, and is configured so that maintenance, replacement, expansion, etc. of the integrated supply system 248 can be performed in units of integrated units.

[0023] The reaction tube 203 is provided with an exhaust pipe 231 for exhausting the atmosphere in the processing chamber 201. A vacuum pump 246 as a vacuum exhaust device is connected to the exhaust pipe 231 via a pressure sensor 245 as a pressure detector (pressure detection unit) for detecting the pressure in the processing chamber 201 and an APC (Auto Pressure Controller) valve 244 as a pressure regulator (pressure adjustment unit). The APC valve 244 can evacuate and stop the evacuation of the processing chamber 201 by opening and closing the valve while the vacuum pump 246 is in operation, and further, can adjust the pressure in the processing chamber 201 by adjusting the valve opening based on pressure information detected by the pressure sensor 245 while the vacuum pump 246 is in operation. An exhaust system is mainly configured by the exhaust pipe 231, the APC valve 244, and the pressure sensor 245. The vacuum pump 246 may be included in the exhaust system.

[0024] Below the manifold 209, a seal cap 219 is provided as a furnace port cover body capable of airtightly closing the lower end opening of the manifold 209. The seal cap 219 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 seal cap 219 as a seal member that abuts against the lower end of the manifold 209. Below the seal cap 219, a rotation mechanism 267 is provided for rotating the boat 217 described later. A rotation shaft 255 of the rotation mechanism 267 is connected to the boat 217 through the seal cap 219. The rotation mechanism 267 is configured to rotate the wafers 200 by rotating the boat 217. The seal cap 219 is configured to be raised and lowered in the vertical direction by a boat elevator 115 as a lifting mechanism installed outside the reaction tube 203. The boat elevator 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 seal cap 219. The boat elevator 115 is configured as a transfer device (transfer mechanism) that transfers the boat 217, that is, the wafers 200, into and out of the processing chamber 201.

[0025] The boat 217 as a substrate support is configured to support multiple wafers, for example 25 to 200 wafers 200, in a horizontal position and aligned vertically with their centers aligned, i.e., arranged at intervals. The boat 217 is made of a heat-resistant material such as quartz or SiC. At the bottom of the boat 217, heat insulating plates 218 made of a heat-resistant material such as quartz or SiC are supported in multiple stages. In this specification, a numerical range such as "25 to 200 sheets" means that the lower limit and the upper limit are included in the range. Therefore, for example, "25 to 200 sheets" means "25 sheets or more and 200 sheets or less". The same applies to other numerical ranges.

[0026] A temperature sensor 263 serving as a temperature detector is installed inside the reaction tube 203. By adjusting the power supply to the heater 207 based on temperature information detected by the temperature sensor 263, the temperature inside the processing chamber 201 can have a desired temperature distribution. The temperature sensor 263 is configured in an L-shape and is installed along the inner wall of the reaction tube 203.

[0027] As shown in FIG. 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 121e. An input / output device 122 configured as, for example, a touch panel is connected to the controller 121. The substrate processing apparatus may be configured to include one control unit or multiple control units. That is, the control for performing the processing sequence described later may be performed using one control unit or multiple control units. The multiple control units may be configured as a control system connected to each other by a wired or wireless communication network, and the control for performing the processing sequence described later may be performed by the entire control system. When the term "control unit" is used in this specification, it may include one control unit, multiple control units, or a control system configured by multiple control units.

[0028] The storage device 121c is composed of, for example, a flash memory, a HDD (Hard Disk Drive), etc. A control program for controlling the operation of the substrate processing apparatus 100, a process recipe in which procedures and conditions of the substrate processing described later are described, etc. are readably stored in the storage device 121c. The process recipe is a combination of procedures in the substrate processing described later that are executed by the controller 121 to obtain a predetermined result, and functions as a program. Hereinafter, the process recipe, the control program, etc. are collectively referred to simply as a program. In addition, the process recipe is also simply referred to as a recipe. In this specification, when the word program is used, 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, data, etc. read by the CPU 121a are temporarily stored.

[0029] The I / O port 121d is connected to the above-mentioned MFCs 241a to 241f, the valves 243a to 243f, the pressure sensor 245, the APC valve 244, the vacuum pump 246, the heater 207, the temperature sensor 263, the rotation mechanism 267, the boat elevator 115, and the like.

[0030] 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 an input of an operation command from the input / output device 122, etc. The CPU 121a is configured to control the flow rate adjustment operation of various gases by the MFCs 241a to 241f, the opening and closing operations of the valves 243a to 243f, the opening and closing operation of the APC valve 244 and 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 temperature adjustment operation of the heater 207 based on the temperature sensor 263, 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 boat elevator 115, etc., in accordance with the contents of the read recipe.

[0031] 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 on which the program is recorded. Hereinafter, these are collectively referred to simply 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 of them. 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.

[0032] (2) Substrate processing As one step in the manufacturing process of a semiconductor device, an example of a step of forming a thin film on a wafer 200 will be described with reference to Fig. 4. In the following description, the operation of each part constituting the substrate processing apparatus 100 is controlled by a controller 121.

[0033] The term "wafer" used in this specification may mean the wafer itself or a laminate of the wafer and a predetermined layer or film formed on its surface. The term "surface of a wafer" used in this specification may mean the surface of the wafer itself or the surface of a predetermined layer or the like formed on the wafer. When described in this specification, "forming a predetermined layer on a wafer" may mean forming a predetermined layer directly on the surface of the wafer itself or forming a predetermined layer on a layer or the like formed on the wafer. When used in this specification, the term "substrate" is synonymous with the term "wafer".

[0034] (Wafer loading) 1, when a plurality of wafers 200 are loaded into the boat 217 (wafer charge), the boat 217 supporting the plurality of wafers 200 is lifted by the boat elevator 115, carried into the processing chamber 201 (boat load), and accommodated in the processing vessel. In this state, the seal cap 219 closes the lower end opening of the manifold 209 via the O-ring 220b.

[0035] (Pressure and temperature regulation) The inside of the processing chamber 201, i.e., the space in which the wafer 200 exists, is evacuated by the vacuum pump 246 so as to reach a desired pressure (vacuum level). At this time, the pressure inside the processing chamber 201 is measured by the pressure sensor 245, and the APC valve 244 is feedback-controlled (pressure adjustment) based on the measured pressure information. The vacuum pump 246 is kept in a constantly operating state at least until the processing of the wafer 200 is completed. Also, the inside of the processing chamber 201 is heated by the heater 207 so as to reach a desired temperature. At this time, the amount of electricity supplied to the heater 207 is feedback-controlled (temperature adjustment) based on temperature information detected by the temperature sensor 263 so as to achieve a desired temperature distribution inside the processing chamber 201. The heating inside the processing chamber 201 by the heater 207 is continued at least until the processing of the wafer 200 is completed.

[0036] [Pre-process] (Time-division supply of accelerator, 1st step) First, in this step, the accelerator is supplied in a time-division manner. In other words, the accelerator is supplied a predetermined number of times (at least once, preferably multiple times). Specifically, the accelerator supply process of opening the valve 243c and supplying the accelerator into the gas supply pipe 232c and the accelerator removal process of closing the valve 243c and stopping the accelerator supply to remove the accelerator from the processing chamber 201 are performed in this order a predetermined number of times (p times, where p is an integer of 1 or 2 or more). In other words, the supply and stop (also called exhaust or purging) of the accelerator are alternately performed in a time-division manner.

[0037] In the accelerator supply step, the accelerator is adjusted in flow rate by the MFC 241c, supplied from the nozzle 249a into the processing chamber 201, and exhausted from the exhaust pipe 231. At this time, the valve 243e may be opened to allow an inert gas to flow into the gas supply pipe 232e. In addition, in order to prevent the accelerator from entering the nozzle 249b, the valve 243f may be opened to allow an inert gas to flow into the gas supply pipe 243b. In addition, in the accelerator removal step, the APC valve 244 of the exhaust pipe 231 is left open, the processing chamber 201 is evacuated by the vacuum pump 246, the accelerator is removed from the wafer 200, and unreacted accelerator and reaction by-products remaining in the processing chamber 201 are removed from the processing chamber 201. At this time, the valves 243e and 243f are left open to maintain the supply of the inert gas as a purge gas into the processing chamber 201.

[0038] In this specification, "time-division" means that the accelerator is divided (separated) in time. For example, in this specification, supplying the accelerator in a time-division manner means that the accelerator is not supplied continuously. In other words, it means that the accelerator is supplied in a pulsed manner. The accelerator can also be supplied intermittently.

[0039] At this time, the main gas supplied in a time-division manner into the processing chamber 201 is the accelerator. In this manner, by supplying the accelerator to the wafer 200 multiple times, the accelerator can be adsorbed onto the wafer 200 without any gaps.

[0040] As the accelerator, a non-reducing oxidizing gas is used. As the oxidizing gas, for example, oxygen (O2) gas, ozone (O3) gas, water vapor (H2O gas), hydrogen peroxide (H2O2) gas, hydrogen (H2) gas + O2 gas, etc. can be used. As the accelerator, one or more of these activated gases can be used. Activated gases include those activated by plasma or thermally. The same applies hereinafter.

[0041] In this specification, the description of two gases together, such as "H2 gas + O2 gas," means a mixed gas of H2 gas and O2 gas. When 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 separately supplied into the processing chamber 201 through different supply pipes and mixed (postmixed) in the processing chamber 201.

[0042] As the promoter, an oxidizing gas that does not contain hydrogen element (H) can be used. As the oxidizing gas that does not contain H, for example, O2 gas, O3 gas, etc. can be used. As the promoter, an activated gas of one or more of these can be used.

[0043] As the inert gas, for example, in addition to nitrogen (N2) gas, rare gases such as argon (Ar) gas, helium (He) gas, neon (Ne) gas, xenon (Xe) gas, etc., can be used. One or more of these can be used as the inert gas.

[0044] By supplying the accelerator, atoms or molecules that accelerate the adsorption of the modifier containing an organic ligand are adsorbed on the wafer 200 (underlying film on the surface). Specifically, by supplying, for example, an oxidizing gas as the accelerator, oxygen radicals (hereinafter, referred to as O-) and O2 are adsorbed on the wafer 200. That is, the surface of the wafer 200 is terminated with O- and O2. In this disclosure, "termination" and "adsorption" may also include a state in which the entire surface of the wafer 200 is not covered. Depending on the gas supply conditions and the surface state of the wafer 200, the entire surface of the wafer 200 may not be covered. In addition, the entire surface of the wafer 200 may not be covered due to the reaction stopping in a self-limiting manner. In this disclosure, the amount of accelerator adsorbed on the wafer 200 can be increased by supplying the accelerator multiple times. In other words, it is possible to approach adsorption of the accelerator to all of the adsorption sites to which the accelerator can be adsorbed.

[0045] In the first step, the pressure of the space above the wafer 200 (processing chamber 201) is set to, for example, 1 to 3990 Pa. The supply flow rate of the accelerator controlled by the MFC 241c is set to, for example, 0.01 to 5.0 slm. In the following, the temperature of the heater 207 is set to such a temperature that the temperature of the wafer 200 is, for example, within a range of 300 to 550° C. In addition, in this disclosure, the expression of a numerical range such as "1 to 3990 Pa" means that the lower limit and the upper limit are included in the range. Therefore, for example, "1 to 3990 Pa" means "1 Pa or more and 3990 Pa or less". The same applies to other numerical ranges.

[0046] (Purge, 2nd step) After a predetermined time has elapsed since the start of the time-division supply of the accelerator, the valve 243c is closed to stop the supply of the accelerator. At this time, the APC valve 244 of the exhaust pipe 231 is left open, and the processing chamber 201 is evacuated by the vacuum pump 246 to remove the residual gas from above the wafer 200, and the unreacted accelerator and reaction by-products remaining in the processing chamber 201 are removed from the processing chamber 201. At this time, the valves 243e and 243f are left open to maintain the supply of the inert gas as a purge gas into the processing chamber 201. The inert gas acts as a purge gas to remove the residual gas from above the wafer 200, and can enhance the effect of removing the unreacted accelerator and reaction by-products remaining in the processing chamber 201 from the processing chamber 201.

[0047] In the second step, the supply flow rates of the inert gases controlled by the MFCs 241e and 241f are set to, for example, 0.1 to 10 slm, respectively.

[0048] (Modifier supply, 3rd step) The valve 243d is opened to allow the modifying agent to flow into the gas supply pipe 232d. The modifying agent has its flow rate adjusted by the MFC 241d, is supplied into the processing chamber 201 from the gas supply hole 250b of the nozzle 249b, and is exhausted from the exhaust pipe 231. At the same time, the valve 243f may be opened to allow an inert gas to flow into the gas supply pipe 232f. Also, in order to prevent the modifying agent from entering the nozzle 249a, the valve 243e may be opened to allow an inert gas to flow into the gas supply pipe 232e.

[0049] At this time, the main gas flowing in the processing chamber 201 is the modifying agent. That is, the modifying agent is supplied to the wafer 200.

[0050] The modifier is a gas containing an organic ligand, i.e., a gas containing an organic compound, such as a gas containing a hydrocarbon group (CH-) or an amine group (NH-).

[0051] As the gas containing an organic compound, a gas not containing a metal element is used. As the gas not containing a metal element, a gas containing at least one selected from the group consisting of an ether compound, a ketone compound, an amine compound containing an amine, and an organic hydrazine compound can be used. As the gas containing an ether compound, a gas containing at least one of dimethyl ether, diethyl ether, methyl ethyl ether, propyl ether, isopropyl ether, furan, tetrahydrofuran, pyran, tetrahydropyran, etc. can be used. As the gas containing a ketone compound, a gas containing at least one of dimethyl ketone, diethyl ketone, methyl ethyl ketone, methyl propyl ketone, etc. can be used. As the gas containing an amine compound, a gas containing at least one of methylamine compounds such as monomethylamine (CH3NH2, also called methylamine), dimethylamine, and trimethylamine, ethylamine compounds such as monoethylamine, diethylamine, and triethylamine, and methylethylamine compounds such as dimethylethylamine and methyldiethylamine can be used. As the gas containing an organic hydrazine compound, a gas containing at least one of methylhydrazine-based gases such as monomethylhydrazine, dimethylhydrazine, trimethylhydrazine, etc. As the modifier, one or more of these can be used.

[0052] As the gas containing an organic compound, a gas containing a metal element is used. As the gas containing a metal element, trimethylaluminum ((CH3)3Al) gas, trimethylgallium ((CH3)3Ga) gas, trimethylindium ((CH3)3In) gas, etc. can be used. As the modifier, one or more of these can be used.

[0053] By supplying the modifier, a part of the modifier reacts with O-, O2, etc. on the wafer 200 to generate reaction by-products such as H2O, and hydrocarbon groups such as alkyl groups such as methyl group (CH3-), ethyl group (C2H5-), propyl group, isopropyl group, and amine groups are adsorbed. By supplying the modifier, it is possible to increase the amount of adsorption of the hydrocarbon groups and amine groups on the wafer 200. Then, in a film forming process described later, a source gas is supplied to the wafer 200 to which the hydrocarbon groups and amine groups are adsorbed, whereby the halogen elements contained in the source gas react with the hydrocarbon groups and amine groups present on the wafer 200, and molecules having a smaller number of molecules and less steric hindrance than the source gas are adsorbed on the wafer 200, and a continuous film with a large amount of adsorption of the source elements is formed.

[0054] Specifically, when an oxidizing gas, O2 gas, is used as the accelerator and a modifier, such as CH3NH2 gas, the supply of CH3NH2 gas causes the O and O2 adsorbed on the wafer 200 to react with CH3NH2, and O and O2 are desorbed from the wafer 200, generating and discharging H2O. Then, hydrocarbon groups such as (CH3)-, (CH3)N-, and (CH3)NH- and amine groups are adsorbed and remain on the wafer 200. At this time, some O and O2 may remain on the wafer 200, but since they are present at the interface between the underlying oxide film and the film formed in the film formation process described below, it is considered that there is little effect on the device characteristics. When titanium tetrachloride (TiCl4) gas is used as the source gas, Cl contained in the TiCl4 gas reacts with (CH3)-, (CH3)N-, (CH3)NH-, etc. on the wafer 200 in the film forming process described later, and is desorbed and discharged as (CH3)Cl, (CH3)NCl, and (CH3)NHCl from the wafer 200. That is, the generation of reaction by-products such as hydrogen chloride (HCl) that inhibit the adsorption of the source element is suppressed.

[0055] In the third step, the pressure in the processing chamber 201 is set to, for example, within a range of 1 to 3990 Pa. The supply flow rate of the modifying agent controlled by the MFC 241d is set to, for example, within a range of 0.01 to 5.0 slm.

[0056] (Purge, 4th step) After a predetermined time has elapsed since the start of the supply of the modifying agent, the valve 243d is closed to stop the supply of the modifying agent. At this time, the APC valve 244 of the exhaust pipe 231 is left open, and the inside of the processing chamber 201 is evacuated by the vacuum pump 246 to remove the residual gas from above the wafer 200, and the unreacted modifying agent and reaction by-products remaining in the processing chamber 201 are removed from the inside of the processing chamber 201. At this time, the valves 243e and 243f are left open to maintain the supply of the inert gas as a purge gas into the processing chamber 201. The supply amount of the inert gas supplied in the fourth step can be the same as that in the second step. In addition, the purge amount (supply amount of the inert gas) can be appropriately adjusted according to the gas remaining in the processing chamber 201. Here, the supply amount means either or both of the supply flow rate and the supply time set by the MFC.

[0057] (Performed a set number of times, 5th step) By performing a cycle of performing the above-mentioned first to fourth steps in this order a predetermined number of times (m times, where m is an integer of 1 or 2 or more), hydrocarbon groups, amine groups, etc. are adsorbed onto the wafer 200. Here, hydrocarbon groups and amine groups such as (CH3)-, (CH3)N-, (CH3)NH-, etc. are adsorbed onto the wafer 200. This suppresses the generation of reaction by-products such as HCl that inhibit the adsorption of source elements by supplying source gas and reactive gas in the film formation process described later.

[0058] For convenience, the above-mentioned pre-processing may be expressed as follows. Similar notations will be used in the following explanations of other embodiments. Here, "→" means to flow in order.

[0059] ((Promoter supply → Purge) × p → Purge → Modifier → Purge) × m (m and p are each an integer of 1 or 2 or greater)

[0060] Although an example in which the modifying agent is supplied only once has been shown, the present invention is not limited to this, and the modifying agent may be supplied as (modifying agent supply→purge)×o (where o is an integer of 1 or 2 or more). By setting o to 2 or more, the amount of the modifying agent adsorbed on the surface of the wafer 200 can be increased. Furthermore, by performing purging, by-products generated when the modifying agent is supplied can be removed from the space in which the wafer 200 exists, and the amount of the modifying agent that reaches the surface of the wafer 200 can be increased.

[0061] [Film forming process] After the above-mentioned pre-processing is performed, the following film-forming process is performed to form a film on the wafer 200.

[0062] (raw gas supply, 6th step) The valve 243a is opened to allow the source gas to flow into the gas supply pipe 232a. The flow rate of the source gas is adjusted by the MFC 241a, and the source gas is supplied into the processing chamber 201 from the gas supply hole 250a of the nozzle 249a and exhausted from the exhaust pipe 231. At this time, the valve 243e may be opened at the same time to allow the inert gas to flow into the gas supply pipe 232e. At this time, in order to prevent the source gas from entering the nozzle 249b, the valve 243f may be opened to allow the inert gas to flow into the gas supply pipe 232f.

[0063] At this time, the main gas flowing in the processing chamber 201 is the source gas. That is, the source gas is supplied to the wafers 200.

[0064] A gas containing a halogen element can be used as the source gas. For example, a gas containing at least one of fluorine (F), chlorine (Cl), bromine (Br), iodine (I), etc. can be used as the source gas. One or more of these can be used.

[0065] As the source gas, a gas containing a halogen element and a metal element can be used. Here, the metal element includes at least one of transition metals from Group 3 to Group 12, Group 13 elements (e.g., aluminum (Al), gallium (Ga), indium (In)), silicon element (Si), etc.

[0066] As a gas containing a halogen element and a group 13 element, for example, aluminum chloride (AlCl3) gas can be used. As a gas containing a halogen element and Si, for example, silicon tetrachloride (SiCl4) gas, dichlorosilane (SiH2Cl2) gas, hexachlorodisilane (Si2Cl6) gas can be used.

[0067] As a gas containing a halogen element and a transition metal, a gas containing at least one of a halogen element and a Group 3 element such as yttrium (Y) or lanthanum (La), a Group 4 element such as cerium (Ce), titanium (Ti), zirconium (Zr), or hafnium (Hf), or a Group 6 element such as chromium (Cr), molybdenum (Mo), or tungsten (W), can be used. Examples of gases that contain halogen elements and transition metals include TiCl4 gas, hafnium chloride (HfCl4) gas, zirconium chloride (ZrCl4) gas, tungsten hexafluoride (WF6) gas, tungsten hexachloride (WCl6) gas, molybdenum pentachloride (MoCl5) gas, molybdenum dioxide dichloride (MoO2Cl2) gas, molybdenum oxide tetrachloride (MoOCl4) gas, molybdenum hexafluoride (MoF6) gas, molybdenum dioxide difluoride (MoO2F2) gas, and molybdenum oxide tetrafluoride (MoOF4) gas. Examples of gases that contain halogen elements and transition metals include one or more of these.

[0068] At this time, the source gas containing a halogen element is supplied to the wafer 200 on which the hydrocarbon group, amine group, etc. derived from the organic ligand-containing gas is adsorbed, i.e., the wafer 200 whose surface is terminated with the hydrocarbon group or amine group. Here, the hydrocarbon group or amine group is adsorbed on the wafer 200 in the pre-process before the film formation process is started.

[0069] The raw material gas is supplied to the wafer 200 on which organic ligands such as hydrocarbon groups and amine groups are exposed. As a result, the halogen elements contained in the raw material gas react with the hydrocarbon groups and amine groups present on the wafer 200, and raw material elements having a smaller molecular size than the raw material gas are adsorbed on the wafer 200. Therefore, steric hindrance is reduced compared to when the raw material gas is adsorbed. That is, the raw material elements having a small molecular size are adsorbed on the wafer 200 (underlying film on the surface), and the adsorption density of the raw material elements on the wafer 200 can be increased, and a raw material-containing layer having a high content of the raw material elements can be formed. At this time, (CH3)Cl, (CH3)NCl, and (CH3)NHCl are generated as by-products. Most of these by-products are desorbed from the wafer 200 and discharged. That is, the generation of reaction by-products such as hydrogen chloride (HCl) that inhibit the adsorption of the raw material elements is suppressed.

[0070] Specifically, as described above, when TiCl4 gas is used as the source gas in this step, Cl in the TiCl4 gas reacts with (CH3)- and (CH3)NH- on the wafer, and is desorbed from the wafer 200 as (CH3)Cl, (CH3)NCl, (CH3)NHCl, etc. Then, TiClx (x is smaller than 4) is adsorbed onto the wafer 200. That is, TiClx, which has less steric hindrance compared to when TiCl4 is adsorbed, is adsorbed onto the wafer 200, and the adsorption density of Ti element on the wafer 200 can be increased, and a Ti-containing layer with a high content of Ti element can be formed.

[0071] In the sixth step, the APC valve 244 is adjusted to set the pressure inside the processing chamber 201 within a range of, for example, 1 to 3990 Pa. The supply flow rate of the source gas controlled by the MFC 241a is set within a range of, for example, 0.1 to 2.0 slm. The time for which the source gas is supplied to the wafer 200 is set within a range of, for example, 0.01 to 30 seconds.

[0072] (Purge, 7th step) After a predetermined time has elapsed since the start of the supply of the source gas, the valve 243a is closed to stop the supply of the source gas. At this time, the APC valve 244 of the exhaust pipe 231 is left open, and the inside of the processing chamber 201 is evacuated by the vacuum pump 246 to remove the residual gas from above the wafer 200, and the unreacted source gas and reaction by-products remaining in the processing chamber 201 are removed from the inside of the processing chamber 201. At this time, the valves 243e and 243f are left open to maintain the supply of the inert gas as the purge gas into the processing chamber 201. The seventh step can be performed under the same conditions as the other purge steps.

[0073] (Reaction gas supply, 8th step) After a predetermined time has elapsed since the start of purging, the valve 243b is opened to allow the reactive gas to flow into the gas supply pipe 232b. The reactive gas has a flow rate adjusted by the MFC 241b, is supplied into the processing chamber 201 through the gas supply holes 250b of the nozzle 249b, and is exhausted from the exhaust pipe 231. At the same time, the valve 243f may be opened to allow the inert gas to flow into the gas supply pipe 232f. Furthermore, in order to prevent the reactive gas from entering the nozzle 249a, the valve 243e may be opened to allow the inert gas to flow into the gas supply pipe 232e.

[0074] At this time, the main gas flowing in the processing chamber 201 is a reactive gas. That is, the reactive gas is supplied to the wafer 200.

[0075] As the reactive gas, for example, an H-containing gas containing hydrogen element (H) can be used. As the H-containing gas, for example, a gas containing H2 gas, ammonia (NH3) gas, hydrazine (N2H4) gas, diazene (N2H2) gas, H2O gas, H2O2 gas, a mixed gas of H2+O2, deuterium (D2) gas, deuterium (ND3) gas, monosilane (SiH4) gas, disilane (Si2H6) gas, trisilane (Si3H8) gas, monoborane (BH3) gas, diborane (B2H6) gas, B3H8 gas, phosphine (PH3) gas, etc. can be used. As the reactive gas, an activated gas of one or more of these can be used.

[0076] By supplying the reactive gas, the reactive gas undergoes a substitution reaction with at least a part of the first layer formed on the wafer 200 to form a second layer. Specifically, when NH3 gas is used as the reactive gas, for example, the NH3 gas undergoes a substitution reaction with at least a part of the Ti-containing layer formed on the wafer 200 by supplying the NH3 gas. During the substitution reaction, Ti contained in the Ti-containing layer and N contained in the NH3 gas are bonded to form a TiN layer on the wafer 200. In addition, during the substitution reaction, the amount of adsorption of halogen elements is reduced in the previous process and the amount of adsorption of Ti is increased in the film formation process, so that the generation of reaction by-products such as HCl is suppressed.

[0077] In the eighth step, the APC valve 244 is adjusted to set the pressure inside the processing chamber 201 to within a range of, for example, 1 to 3990 Pa. The supply flow rate of the reactive gas controlled by the MFC 241b is set to within a range of, for example, 0.1 to 30 slm. The time for which the reactive gas is supplied to the wafer 200 is set to within a range of, for example, 0.01 to 30 seconds.

[0078] (Purge, 9th step) After a predetermined time has elapsed since the start of the supply of the reactive gas, the valve 243b is closed to stop the supply of the reactive gas. At this time, the APC valve 244 of the exhaust pipe 231 is left open, and the processing chamber 201 is evacuated by the vacuum pump 246 to remove residual gas from above the wafer 200, and the unreacted reactive gas or the reactive gas that has contributed to the formation of the second layer remaining in the processing chamber 201 and the reaction by-products are removed from the processing chamber 201. At this time, the valves 243e and 243f are left open to maintain the supply of the inert gas as a purge gas into the processing chamber 201.

[0079] That is, the unreacted gas remaining in the processing chamber 201 or the reaction gas that has contributed to the formation of the second layer and the above-mentioned reaction by-products are removed from the processing chamber 201. The inert gas acts as a purge gas.

[0080] The ninth step can be carried out under the same conditions as the other purge steps.

[0081] (Performed a set number of times, 10th step) By performing a cycle of sequentially performing the above-mentioned sixth to ninth steps a predetermined number of times (n times, where n is an integer of 1 or 2 or more), a predetermined film of a predetermined thickness is formed on the wafer 200. In this case, a metal-containing film, for example, a titanium nitride (TiN) film, is formed as the predetermined film.

[0082] The above film forming process can be described as follows.

[0083] (Source gas → Purge → Reactant gas → Purge) × n (n is an integer of 1 or 2 or more)

[0084] (Performed a set number of times, step 11) After the above-mentioned tenth step is performed, the process returns to the first step. Then, the cycle of performing the above-mentioned fifth step and the above-mentioned tenth step in this order is performed a predetermined number of times (q times, where q is an integer of 1 or 2 or more) to form a predetermined film of a predetermined thickness on the wafer 200. Here, a metal-containing film, for example, a titanium nitride (TiN) film, is formed as the predetermined film.

[0085] Therefore, the processing in the above substrate processing steps can be expressed as follows.

[0086] [((Promoter supply → Purge 1) × p → Purge 2 → Modifier → Purge 3) × m → (Raw material gas → Purge 4 → Reactant gas → Purge 5) × n] × q (p, m, n, and q are integers of 1 or 2 or more, and may be different numbers and are adjusted appropriately.) Here, purge 1, purge 2, and purge 3 do not necessarily have to be performed.

[0087] (After purging and atmospheric pressure recovery) An inert gas is supplied into the processing chamber 201 from each of the gas supply pipes 243e and 243f, and exhausted from the exhaust pipe 231. The inert gas acts as a purge gas, whereby the processing chamber 201 is purged with the inert gas, and gas and reaction by-products remaining in the processing chamber 201 are removed from the processing chamber 201 (after-purge). Thereafter, the atmosphere in the processing chamber 201 is replaced with the inert gas (inert gas replacement), and the pressure in the processing chamber 201 is returned to normal pressure (return to atmospheric pressure).

[0088] (Wafer removal) Thereafter, the seal cap 219 is lowered by the boat elevator 115 to open the lower end of the manifold 209. Then, the processed wafers 200 supported by the boat 217 are unloaded from the lower end of the manifold 209 to the outside of the reaction tube 203 (boat unloading). Thereafter, the processed wafers 200 are removed from the boat 217 (wafer discharging).

[0089] Here, a film formed on the wafer 200 using a substrate processing sequence that does not include a pre-processing step may grow in islands rather than as a continuous film. That is, the adsorption of the raw material elements onto the wafer 200 becomes insufficient, resulting in poor coverage. In contrast, a film formed on the wafer 200 using the substrate processing sequence described above has small crystal grains, is densely formed continuously, and has a high coverage.

[0090] In other words, by performing a pre-processing step before the film formation step, it is possible to promote the adsorption of the source elements onto the wafer 200, thereby increasing the adsorption density of the source elements and forming a film with a high content of the source elements.

[0091] That is, by supplying an accelerator and a modifier before forming a film, it is possible to promote the adsorption of the source elements onto the wafer surface, thereby forming a thin film with a high coverage rate.

[0092] (3) Effects of this mode According to this aspect, one or more of the following effects can be obtained. (a) The properties of the film formed on the substrate can be improved. (b) The film formed on the substrate can be grown continuously. Here, "continuous" means that the crystals of the film material are connected and the spacing between the crystals is small. (c) It becomes possible to increase the adsorption density of the raw material elements and improve the coverage rate. (d) In the film formation process, the generation of reaction by-products such as HCl that inhibit the adsorption of raw material elements can be suppressed.

[0093] (4) Other aspects Although one embodiment of the present disclosure has been specifically described above, the present disclosure is not limited to the above embodiment and can be modified in various ways without departing from the spirit and scope of the present disclosure.

[0094] (Variation 1) In this modification, an organic gas is used as the accelerator in the above-mentioned pre-process. As the organic gas, for example, a gas containing an alkane is used. As the gas containing an alkane, C n H 2n+2 For example, gases including methane (CH4), ethane (C2H6), propane (C3H8), etc. As the promoter, one or more of these can be used.

[0095] By supplying an organic gas as a promoter, a hydrocarbon group is adsorbed on the wafer 200. That is, by supplying an organic gas, the surface of the wafer 200 is terminated with CH-. This promotes the adsorption of the modifier. When an organic gas is used, the possibility of excessively altering the state of the film exposed on the surface of the wafer 200 can be reduced. For example, when the surface of the wafer 200 is a film containing a metal element, an oxide film containing a metal element may be formed when the oxidizing gas of the present disclosure is used. The formation of the oxide film may affect the characteristics of the semiconductor device. On the other hand, when an organic gas is used, it is possible to suppress the occurrence of such a problem. When the film exposed on the surface of the wafer 200 contains oxygen, the possibility of such a problem occurring is low even when the oxidizing gas of the present disclosure is used.

[0096] Even in this case, the same effects as those of the substrate processing sequence shown in FIG. 4 described above can be obtained.

[0097] (Variation 2) In this modification, the above-mentioned film forming process is performed as shown below. "+" means that there is a timing for flowing simultaneously. "( )" means that it may be omitted.

[0098] (raw material gas → raw material gas + reducing gas → (reducing gas) → purge → reactive gas → purge) × n (n is an integer of 1 or 2 or more)

[0099] Even in this case, the same effects as those of the substrate processing sequence shown in FIG. 4 described above can be obtained.

[0100] Specifically, for example, TiCl4 gas can be used as the source gas, NH3 gas as the reactive gas, and SiH4 gas as the reducing gas. The above sequence can also be suitably applied to the formation of a TiN film or the like.

[0101] (Variation 3) In the above embodiment, the above substrate processing sequences are continuously (in-situ) performed in the same processing chamber (processing vessel). The present disclosure is not limited to the above embodiment, and may be performed using a cluster-type substrate processing apparatus 10 having a plurality of processing furnaces 202a-202d and a plurality of processing chambers 201a-201d connected to a vacuum transfer chamber 103 in which a substrate transfer device 112 is installed, for example, as shown in FIG. That is, at least one process in the above substrate processing sequence and another process may be performed in different processing chambers (processing vessels) (ex-situ).

[0102] In this modification, the controller 121 performs, for example, the above-mentioned pre-process and the above-mentioned film-forming process separately in different processing chambers of different processing furnaces. In this case, the controller 121A that performs the pre-process in the processing furnace that performs the pre-process and the controller 121B that performs the film-forming process in the processing furnace that performs the film-forming process are controlled by the host computer or the controller 121 as a group management control device. That is, the pre-process of supplying the accelerator and the modifier and the film-forming process of supplying the raw material gas and the reactive gas are separately performed in different processing chambers by the substrate processing apparatus 10. In either case, the same effect as the above-mentioned embodiment can be obtained. Note that, when these processes are performed in-situ, contamination of the substrate and changes in the surface state of the substrate that may occur due to the substrate being carried out of the processing chamber or carried in from outside the processing chamber between processes can be suppressed. Also, when these processes are performed in-situ, the transition time between processes can be shortened. On the other hand, when these processes are performed ex-situ, the processes can be performed in parallel in different processing chambers, and the productivity can be increased accordingly.

[0103] When using these substrate processing apparatuses, each process can be performed according to the same process procedures and under the same process conditions as in the above-described aspects and modifications, and the same effects as in the above-described aspects and modifications can be obtained.

[0104] In the above embodiment, the accelerator is supplied in a time-division manner in the pre-processing step, but the present invention is not limited to this and may be applied to a case where the accelerator is supplied continuously.

[0105] In the above embodiment, the inert gas is continuously supplied during the substrate processing step. However, the present invention is not limited to this, and the inert gas may be supplied only during the purge step.

[0106] In the above-mentioned embodiment, an example of forming a film using a batch-type substrate processing apparatus that processes multiple substrates at a time has been described. The present disclosure is not limited to the above-mentioned embodiment, and can be suitably applied to, for example, a case where a film is formed using a single-wafer type substrate processing apparatus that processes one or several substrates at a time. In the above-mentioned embodiment, an example of forming a film using a substrate processing apparatus having a hot-wall type processing furnace has been described. The present disclosure is not limited to the above-mentioned embodiment, and can be suitably applied to, for example, a case where a film is formed using a substrate processing apparatus having a cold-wall type processing furnace.

[0107] The above-mentioned aspects and modifications may be used in appropriate combination. The processing procedures and processing conditions in such a case may be the same as those of the above-mentioned aspects and modifications.

[0108] The above describes the aspects and modifications of the present disclosure in detail. However, the aspects and modifications of the present disclosure are not limited to the above aspects and modifications, and various changes can be made without departing from the spirit of the present disclosure. [Explanation of symbols]

[0109] 200 wafers (substrates)

Claims

1. (a) providing a substrate with a non-reducing promoter that promotes adsorption of a modifier comprising an organic ligand; (b) applying the modifier to the substrate; (c) after carrying out (a) and (b), forming a film on the substrate; A substrate processing method comprising the steps of:

2. The substrate processing method according to claim 1 , wherein the modifying agent does not contain a metal element.

3. The substrate processing method according to claim 1 , wherein the modifying agent contains a metal element.

4. 2. The method of claim 1, wherein the modifying agent includes a hydrocarbon group.

5. The method of claim 1 , wherein the modifying agent comprises an amine.

6. 2. The method of claim 1, wherein the accelerator is oxidizing.

7. 7. The substrate processing method according to claim 6, wherein the accelerator is a gas that does not contain hydrogen elements.

8. 2. The substrate processing method according to claim 1, wherein the accelerator is an organic gas.

9. 9. The method of claim 8, wherein the accelerator is a gas containing an alkane.

10. 2. The substrate processing method according to claim 1, wherein in (c), a gas containing a halogen element is used.

11. The substrate processing method according to claim 10 , wherein the gas containing a halogen element contains a metal element.

12. 2. The substrate processing method according to claim 1, wherein in (c), a gas containing a metal element and a halogen element is used, and the modifying agent does not contain a metal element.

13. The method of claim 1 , wherein (a) is performed multiple times.

14. (d) removing the promoter; 2. The substrate processing method according to claim 1, wherein steps (a) and (d) are performed in this order a predetermined number of times.

15. 14. The substrate processing method according to claim 1, further comprising repeating steps (a) and (b) in this order a predetermined number of times.

16. The method of claim 15, further comprising repeating steps (e) and (c) a predetermined number of times.

17. 11. The substrate processing method according to claim 10, wherein in (c), a reactive gas containing hydrogen elements is supplied.

18. (a) providing a substrate with a non-reducing promoter that promotes adsorption of a modifier comprising an organic ligand; (b) applying the modifier to the substrate; (c) after carrying out (a) and (b), forming a film on the substrate; A method for manufacturing a semiconductor device having the above structure.

19. (a) providing a substrate with a non-reducing promoter that promotes adsorption of a modifier comprising an organic ligand; (b) applying the modifier to the substrate; (c) after carrying out (a) and (b), forming a film on the substrate; A program for causing a computer to execute the above in a substrate processing apparatus.

20. a first gas supply system capable of supplying a non-reducing promoter that includes an organic ligand and promotes adsorption of the modifier to the substrate; a second gas supply system capable of supplying the modifier to the substrate; (a) providing the promoter to the substrate; (b) supplying the modifying agent to the substrate; (c) a control unit configured to be able to control the first gas supply system and the second gas supply system so as to perform a process of forming a film on the substrate after performing the processes (a) and (b); and A substrate processing apparatus comprising:

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