Processing method, method of manufacturing semiconductor device, processing apparatus, and program product

Abstract

The invention relates to a processing method, a method of manufacturing a semiconductor device, a processing apparatus, and a program product. Provided is a technique for improving controllability of an etching amount. A first film exposed on the surface of a substrate is etched by performing a cycle for a predetermined number of times in which the following steps are not performed at the same time: (a) a step for forming a first modified layer on at least a part of the surface of the first film by supplying a first gas to the substrate; and (b) a step of supplying a second gas having a molecular structure different from that of the first gas to the substrate, thereby generating an etching seed by reacting the second gas with the first modified layer and / or activating the first modified layer using the second gas, and etching at least a portion of the first film using the etching seed.

Description

[0001] This application is a divisional application of Chinese invention patent application No. 202110634870.4, with the application date of June 7, 2021 and the invention name of "Manufacturing method, substrate processing device and recording medium of semiconductor device". Technical Field

[0002] The present invention relates to a method for manufacturing a semiconductor device, a substrate processing apparatus and a recording medium. Background Art

[0003] As one of the steps in the manufacturing process of a semiconductor device, a process of etching a film exposed on the surface of a substrate is sometimes performed (for example, see Patent Document 1).

[0004] As semiconductor devices become larger in size, their processing dimensions become smaller and more complex, it is necessary to repeat the high-precision patterning process including the above-mentioned etching process, which has become one of the reasons for the increase in cost. In response to this, there is a technology for performing the above-mentioned etching process at the atomic layer level (hereinafter also referred to as atomic layer etching). Such a highly controllable process has attracted attention as an effective technology for reducing the number of processes. In the past, the technology related to atomic layer etching was mainly a method using plasma.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2019-160962 Summary of the invention

[0008] Problems to be solved by the invention

[0009] In the conventional etching of films by etching gas, the etching amount depends on the partial pressure of the etching gas (≈ the supply amount). Therefore, the etching amount varies due to the pressure distribution of the gas generated in the reaction system. For example, in the case of etching a film formed inside a groove, even with the same processing time, the etching amount of the film formed at the bottom of a deep groove where gas is difficult to be supplied is less than that of the film formed near the opening of the groove where gas is easily supplied. As such, in the conventional etching process of films by etching gas, there is a problem in the controllability of the etching amount.

[0010] Therefore, an object of the present invention is to provide a technique for improving the controllability of the etching amount.

[0011] Means for solving problems

[0012] According to one aspect of the present invention, there is provided a technique for etching a first film exposed on a surface of a substrate by performing a cycle of the following steps non-simultaneously for a predetermined number of times:

[0013] (a) supplying a first gas to a substrate to form a first modified layer on at least a portion of a surface of the first film; and

[0014] (b) supplying a second gas having a molecular structure different from that of the first gas to the substrate, thereby generating an etching species by at least one of causing the second gas to react with the first modified layer and activating the first modified layer using the second gas, and etching at least a portion of the first film using the etching species.

[0015] The present invention specifically relates to the following items:

[0016] <1> , a method for manufacturing a semiconductor device, wherein a first film exposed on a surface of a substrate is etched by performing a cycle of the following steps non-simultaneously for a predetermined number of times:

[0017] (a) supplying a first gas to the substrate to form a first modified layer on at least a portion of the surface of the first film; and

[0018] (b) supplying a second gas having a molecular structure different from that of the first gas to the substrate, thereby generating an etching species by at least one of causing the second gas to react with the first modified layer and activating the first modified layer using the second gas, and etching at least a portion of the first film using the etching species.

[0019] <2> ,according to <1> The method for manufacturing a semiconductor device is characterized in that, in (a), at least a portion of the molecules of the first gas are physically adsorbed or chemically adsorbed on at least a portion of the surface of the first film, thereby forming the first modified layer.

[0020] <3> ,according to <1> The method for manufacturing a semiconductor device, wherein in (a), the first modified layer is formed by generating a compound through a chemical reaction between at least a portion of the molecules of the first gas and at least a portion of the atoms or molecules on the surface of the first film.

[0021] <4> ,according to <1> The method for manufacturing a semiconductor device, wherein in (b), the second gas is supplied to the substrate under the condition that a reaction of the second gas with the first modified layer occurs predominantly compared with a reaction of the second gas with the first film.

[0022] <5> ,according to <1> The method for manufacturing a semiconductor device, wherein in (b), the second gas is supplied to the substrate under the condition that a reaction between the second gas and the first modified layer proceeds but a reaction between the second gas and the first film does not proceed.

[0023] <6> ,according to <1> The method for manufacturing a semiconductor device, wherein, in (b), the second gas is supplied to the substrate under the condition that activation of the first modified layer caused by the second gas is dominant over activation of the first film caused by the second gas.

[0024] <7> ,according to <1> The method for manufacturing a semiconductor device, wherein in (b), the second gas is supplied to the substrate under the condition that activation of the first modified layer by the second gas proceeds but activation of the first film by the second gas does not proceed.

[0025] <8> ,according to <1> The method for manufacturing a semiconductor device, wherein, in (b), the second gas is supplied to the substrate under conditions where etching of at least a portion of the first film caused by the etching species predominantly occurs compared to the reaction of the second gas with the first film.

[0026] <9> ,according to <1> The method for manufacturing a semiconductor device, wherein in (b), the second gas is supplied to the substrate under the condition that etching of at least a portion of the first film by the etching species proceeds but a reaction of the second gas with the first film does not proceed.

[0027] <10> ,according to <1> The method for manufacturing a semiconductor device, wherein in (b), a second modified layer is further formed on at least a portion of the surface of the first film at least partially etched.

[0028] <11> ,according to <10> The method for manufacturing a semiconductor device, wherein, in (a) after the second cycle, the first gas is supplied to the substrate so that the first gas reacts with the second modified layer to remove the second modified layer, and the first modified layer is formed on at least a portion of the surface of the first film from which the second modified layer is removed.

[0029] <12> ,according to <1> In the method for manufacturing a semiconductor device, the first film includes a nitrogen-containing film, a transition metal film or a semiconductor film.

[0030] <13> ,according to <1> The method for manufacturing a semiconductor device, wherein a second film is exposed on the surface of the substrate,

[0031] By performing the cycle a predetermined number of times, the first film is selectively etched with respect to the second film.

[0032] <14> ,according to <13> In the method for manufacturing a semiconductor device, the first film includes a nitrogen-containing film, a transition metal film or a semiconductor film, and the second film includes an oxygen-containing film or a non-transition metal film.

[0033] <15> ,according to <14> In the method for manufacturing a semiconductor device, the nitrogen-containing film comprises a silicon-based nitrogen-containing film, a boron-based nitrogen-containing film or a metal-based nitrogen-containing film.

[0034] <16> ,according to <14> In the method for manufacturing a semiconductor device, the oxygen-containing film comprises a silicon-based oxygen-containing film or a metal-based oxygen-containing film.

[0035] <17> ,according to <13> In the method for manufacturing a semiconductor device, the first film is etched with a selectivity of 5:1 or more with respect to the second film by performing the cycle a predetermined number of times.

[0036] <18> ,according to <1> The method for manufacturing a semiconductor device, wherein the first gas includes one or more of a silicon-containing gas, a metal-containing gas, an oxygen-containing gas, a nitrogen- and hydrogen-containing gas, a boron-containing gas, a phosphorus-containing gas, and a halogen-containing gas,

[0037] The second gas includes at least one of a halogen-containing gas and an acetylacetone-based gas.

[0038] <19> ,according to <1> The method for manufacturing a semiconductor device, wherein the cycle is performed a specified number of times in a non-plasma atmosphere.

[0039] <20> ,according to <1> In the method for manufacturing a semiconductor device, the cycle is performed a predetermined number of times under the condition that the etching reaction of the first film is difficult to proceed when at least one of the first gas and the second gas exists alone.

[0040] <21> , a substrate processing method, wherein a first film exposed on a surface of a substrate is etched by performing a cycle of the following steps non-simultaneously for a predetermined number of times:

[0041] (a) supplying a first gas to the substrate to form a first modified layer on at least a portion of the surface of the first film; and

[0042] (b) supplying a second gas having a molecular structure different from that of the first gas to the substrate, thereby generating an etching species by at least one of causing the second gas to react with the first modified layer and activating the first modified layer using the second gas, and etching at least a portion of the first film using the etching species.

[0043] <22> , a substrate processing device, comprising:

[0044] a processing chamber in which the substrate is processed;

[0045] a first gas supply system for supplying a first gas to the substrate in the processing chamber;

[0046] a second gas supply system for supplying a second gas having a molecular structure different from that of the first gas to the substrate in the processing chamber;

[0047] a temperature regulator that regulates the temperature of the substrate within the processing chamber; and

[0048] A control unit configured to control the first gas supply system, the second gas supply system, and the temperature regulator to perform a process of etching the first film exposed on the surface of the substrate in the process chamber by performing a cycle of non-simultaneously performing the following processes a predetermined number of times:

[0049] (a) supplying the first gas to the substrate to form a first modified layer on at least a portion of the surface of the first film; and

[0050] (b) supplying the second gas to the substrate to generate etching species by at least one of causing the second gas to react with the first modified layer and activating the first modified layer by the second gas, and etching at least a portion of the first film using the etching species.

[0051] <23> , a computer-readable recording medium having the following program recorded thereon, the program causing a substrate processing apparatus to perform, through a computer, a step of etching a first film exposed on a surface of a substrate by performing a cycle of performing the following steps non-simultaneously a predetermined number of times in a processing chamber of the substrate processing apparatus:

[0052] (a) supplying a first gas to a substrate to form a first modified layer on at least a portion of a surface of the first film; and

[0053] (b) supplying a second gas having a molecular structure different from that of the first gas to the substrate, thereby generating an etching species by at least one of causing the second gas to react with the first modified layer and activating the first modified layer using the second gas, and etching at least a portion of the first film using the etching species.

[0054] Effects of the Invention

[0055] According to the present invention, it is possible to provide a technique for improving the controllability of the etching amount. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 11 is a schematic diagram of the structure of a vertical processing furnace of a substrate processing apparatus preferably used in one embodiment of the present invention, and shows a processing furnace 202 portion in a vertical cross-sectional view.

[0057] Figure 2 This is a schematic diagram of a vertical processing furnace of a substrate processing device preferably used in one embodiment of the present invention. Figure 1 A cross-sectional view taken along line AA shows a portion of the processing furnace 202 .

[0058] Figure 3 1 is a schematic diagram of the configuration of a controller 121 of a substrate processing apparatus preferably used in one embodiment of the present invention, and is a diagram showing a control system of the controller 121 in the form of a block diagram.

[0059] Figure 4 This is a diagram showing a gas supply sequence in an etching process according to one embodiment of the present invention.

[0060] Figure 5 (a) is a partially enlarged cross-sectional view of the wafer 200 in which the first gas 10 is supplied to the wafer 200 having the base 200a exposed on the surface, the first gas 10 is adsorbed on the surface of the base 200a and a first modified layer 200b is formed; Figure 5 (b) is a partially enlarged cross-sectional view of the wafer 200 in a state where the second gas 20 is supplied to the wafer 200 on which the first modified layer 200 b is formed; Figure 5 (c) is a partially enlarged cross-sectional view of the wafer 200 in a state where the first modified layer 200b is activated using the second gas 20 to generate etching species 200c;

[0061] Figure 5 (d) is a partially enlarged cross-sectional view of the wafer 200 in a state where a portion of the surface of the substrate 200a is etched using the etching species 200c and a first product 12 and a second product 14 are generated during the etching; Figure 5 (e) is a partially enlarged cross-sectional view of the wafer 200 showing the behavior of the first product 12 and the second product 14 on the surface of the substrate 200a whose surface is partially etched; Figure 5 (f) is a partially enlarged cross-sectional view of the wafer 200 showing a state in which the second product 14 remains and / or is adsorbed on the surface of the substrate 200a whose surface is partially etched; Figure 5 (g) is a partially enlarged cross-sectional view of a wafer 200 in a state where at least one of the second product 14, the second gas 20, and the substrate 200a whose surface is partially etched reacts, and a second modified layer 200d is formed on the surface of the substrate 200a whose surface is partially etched; Figure 5(h) is a partially enlarged cross-sectional view of the wafer 200 in which the first gas 10 is supplied to the wafer 200 having the second modified layer 200d formed on the surface of the substrate 200a whose surface is partially etched, and the first gas is adsorbed on the surface of the second modified layer 200d; Figure 5 (i) is a partially enlarged cross-sectional view of a wafer 200 in which a product 30 is generated on the surface of a base 200a whose surface is partially etched due to the reaction between the first gas 10 and the second modified layer 200d; Figure 5 (j) is a partially enlarged cross-sectional view of the wafer 200 in a state where a product 30 generated on the surface of the substrate 200a, a portion of the surface of which is etched, is separated from the surface of the substrate 200a; Figure 5 (k) is a partially enlarged cross-sectional view of the wafer 200 showing a state in which the surface of the partially etched substrate 200 a is exposed again after the product 30 on the surface of the partially etched substrate 200 a is detached.

[0062] Figure 6 This is a graph showing the measurement results of the etching rate in Reference Example 1.

[0063] Figure 7 This is a graph showing the measurement results of the etching rate in Reference Example 2.

[0064] Figure 8 This is a graph showing the measurement results of the etching rate in Examples.

[0065] Fig. 9 (a) is a partially enlarged cross-sectional view of the wafer 200 before etching the wafer 200 with the substrate 200a and the substrate 200e exposed on the surface; Fig. 9 (b) is a partially enlarged cross-sectional view of the wafer 200 in the middle of the etching process when the wafer 200 with the base 200a and the base 200e exposed on the surface is etched; Fig. 9 (c) is a partially enlarged cross-sectional view of the wafer 200 after the wafer 200 with the base 200a and the base 200e exposed on the surface is etched. DETAILED DESCRIPTION

[0066] <One aspect of the present invention>

[0067] The following mainly refers to Figure 1 to Figure 4 , Figure 5 (a)~ Figure 5(k) This describes one embodiment of the present invention. It should be noted that the drawings used in the following description are all schematic diagrams, and the dimensional relationships of the elements in the drawings, the ratios of the elements, etc. are not necessarily consistent with the actual ones. In addition, among multiple drawings, the dimensional relationships of the elements and the ratios of the elements are not necessarily consistent either.

[0068] (1) Configuration of the substrate processing apparatus

[0069] As Figure 1 shown, the processing furnace 202 has a heater 207 as a heating mechanism (temperature regulator, temperature adjustment unit). The heater 207 is cylindrical in shape and is vertically installed by being supported on a holding plate. The heater 207 also functions as an activation mechanism (excitation unit) that activates (excites) a gas using heat.

[0070] Inside the heater 207, a reaction tube 203 is arranged concentrically with the heater 207. The reaction tube 203 is made of a heat-resistant material such as quartz (SiO 2 ) or silicon carbide (SiC), and is formed in a cylindrical shape with a closed upper end and an open lower end. Below the reaction tube 203, a manifold 209 is arranged concentrically with the reaction tube 203. The manifold 209 is made of a metal material such as stainless steel (SUS), and is formed in a cylindrical shape with open upper and lower ends. The upper end portion of the manifold 209 is configured to engage with the lower end portion of the reaction tube 203 and support the reaction tube 203. An O-ring 220a is provided between the manifold 209 and the reaction tube 203 as a sealing member. The reaction tube 203 is vertically installed in the same way as the heater 207. The processing container (reaction container) is mainly composed of the reaction tube 203 and the manifold 209. A processing chamber 201 is formed in the cylindrical hollow portion of the processing container. The processing chamber 201 is configured to be able to accommodate a wafer 200 as a substrate. Processing of the wafer 200 is performed inside this processing chamber 201.

[0071] Inside the processing chamber 201, nozzles 249a to 249c as the first to third supply portions are provided so as to penetrate the side walls of the manifold 209. The nozzles 249a to 249c are also respectively referred to as the first to third nozzles. The nozzles 249a to 249c are made of a heat-resistant material such as quartz or SiC. Gas supply pipes 232a to 232c are respectively connected to the nozzles 249a to 249c. The nozzles 249a to 249c are different nozzles from each other, and the nozzles 249a and 249c are respectively adjacently arranged to the nozzle 249b.

[0072] On the gas supply pipes 232a to 232c, mass flow controllers (MFC) 241a to 241c as flow controllers (flow control units) and valves 243a to 243c as on-off valves are provided in order from the upstream side of the gas flow. Gas supply pipes 232d to 232f are connected to the downstream side of the gas supply pipes 232a to 232c compared to the valves 243a to 243c. On the gas supply pipes 232d to 232f, MFCs 241d to 241f and valves 243d to 243f are provided in order from the upstream side of the gas flow. The gas supply pipes 232a to 232f are made of metal materials such as SUS, for example.

[0073] like Figure 2 As shown in FIG. 1 , the nozzles 249a to 249c are arranged in a circular ring-shaped space between the inner wall of the reaction tube 203 and the wafer 200 in a plan view, and are respectively arranged in a manner of standing upward in the arrangement direction of the wafer 200 from the lower part to the upper part of the inner wall of the reaction tube 203. That is, the nozzles 249a to 249c are respectively arranged along the wafer arrangement area in the area which is on the side of the wafer arrangement area where the wafers 200 are arranged and horizontally surrounds the wafer arrangement area. When viewed from above, the nozzle 249b is arranged in a manner of facing the exhaust port 231a described later on a straight line with the center of the wafer 200 carried into the processing chamber 201 sandwiched therebetween. The nozzles 249a and 249c are arranged in a manner of sandwiching a straight line L passing through the center of the nozzle 249b and the exhaust port 231a from both sides along the inner wall of the reaction tube 203 (the outer periphery of the wafer 200). The straight line L is also a straight line passing through the nozzle 249b and the center of the wafer 200. That is, the nozzle 249c may be arranged on the opposite side of the nozzle 249a with the straight line L sandwiched therebetween. The nozzles 249a and 249c are arranged symmetrically with the straight line L as the axis of symmetry. Gas supply holes 250a to 250c for supplying gas are respectively provided on the side surfaces of the nozzles 249a to 249c. The gas supply holes 250a to 250c are respectively opened in a manner opposite to (facing) the exhaust port 231a when viewed from above, so that gas can be supplied to the wafer 200. A plurality of gas supply holes 250a to 250c are provided in a range from the lower part to the upper part of the reaction tube 203.

[0074] The first gas is supplied from the gas supply pipe 232a through the MFC 241a, the valve 243a, and the nozzle 249a into the processing chamber 201. The first gas functions as a modifier or a modified gas.

[0075] The second gas is supplied from the gas supply pipe 232b via the MFC 241b, the valve 243b, and the nozzle 249b into the processing chamber 201. The second gas is a gas having a molecular structure different from that of the first gas, and functions as an activation gas or a reaction gas.

[0076] The third gas is supplied from the gas supply pipe 232c through the MFC 241c, the valve 243c, and the nozzle 249c into the processing chamber 201. The third gas functions as a pre-processing gas.

[0077] Inert gas is supplied from gas supply pipes 232d to 232f into the processing chamber 201 via MFCs 241d to 241f, valves 243d to 243f, gas supply pipes 232a to 232c, and nozzles 249a to 249c. The inert gas functions as a purge gas, a carrier gas, a dilution gas, and the like.

[0078] The first gas supply system (modifier supply system, modified gas supply system) is mainly composed of the gas supply pipe 232a, MFC241a, and valve 243a. The second gas supply system (activation gas supply system, reaction gas supply system) is mainly composed of the gas supply pipe 232b, MFC241b, and valve 243b. The third gas supply system (pretreatment gas supply system) is mainly composed of the gas supply pipe 232c, MFC241c, and valve 243c. The inactive gas supply system is mainly composed of the gas supply pipes 232d to 232f, MFC241d to 241f, and valves 243d to 243f.

[0079] Any or all of the various gas supply systems described above may be configured as an integrated gas supply system 248 that is integrated with valves 243a to 243f, MFCs 241a to 241f, and the like. The integrated gas supply system 248 is configured to be connected to the gas supply pipes 232a to 232f, respectively, and the controller 121 described later controls the supply of various gases to the gas supply pipes 232a to 232f, that is, the opening and closing of the valves 243a to 243f, the flow rate adjustment by the MFCs 241a to 241f, and the like. The integrated gas supply system 248 is configured as an integrated unit of an integral type or a split type, and is configured to be detachable relative to the gas supply pipes 232a to 232f, and the integrated gas supply system 248 can be maintained, replaced, or added, and the like, as an integrated unit.

[0080] An exhaust port 231a for exhausting the atmosphere in the processing chamber 201 is provided at the lower side wall of the reaction tube 203. Figure 2 As shown, the exhaust port 231a is provided at a position opposite (facing) the nozzles 249a to 249c (gas supply holes 250a to 250c) sandwiching the wafer 200 when viewed from above. The exhaust port 231a may also be provided from the lower part to the upper part of the side wall of the reaction tube 203, that is, along the wafer arrangement area. The exhaust pipe 231 is connected to the exhaust port 231a.

[0081] On the exhaust pipe 231, a vacuum pump 246 as a vacuum exhaust device is connected 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 regulation unit). The APC valve 244 is configured to open and close the valve in a state where the vacuum pump 246 is operating, so that vacuum exhaust and stop of vacuum exhaust in the processing chamber 201 can be performed. In addition, by adjusting the valve opening based on the pressure information detected by the pressure sensor 245 in a state where the vacuum pump 246 is operating, the pressure in the processing chamber 201 can be adjusted. The exhaust system is mainly composed of the exhaust pipe 231, the APC valve 244, and the pressure sensor 245. It is also possible to consider including the vacuum pump 246 in the exhaust system.

[0082] Below the manifold 209, a sealing cover 219 as a furnace opening cover is provided, and the sealing cover 219 can airtightly seal the lower end opening of the manifold 209. The sealing cover 219 is made of a metal material such as SUS and is formed in a disc shape. An O-ring 220b as a sealing member that abuts against the lower end of the manifold 209 is provided on the upper surface of the sealing cover 219.

[0083] Below the sealing cover 219, a rotation mechanism 267 for rotating a susceptor 217 described later is provided. The rotation shaft 255 of the rotation mechanism 267 is connected to the susceptor 217 so as to penetrate the sealing cover 219. The rotation mechanism 267 is configured to rotate the wafer 200 by rotating the susceptor 217. The sealing cover 219 is configured to move up and down in the vertical direction by a susceptor elevator 115 as a lifting mechanism provided outside the reaction tube 203. The susceptor elevator 115 is a transfer device (transfer mechanism) configured to transfer the wafer 200 into and out of (transfer) the processing chamber 201 by moving the sealing cover 219 up and down.

[0084] Below the manifold 209, a shutter 219s as a furnace opening cover is provided, and the shutter 219s can airtightly seal the lower end opening of the manifold 209 in a state where the sealing cover 219 is lowered and the susceptor 217 is taken out of the processing chamber 201. The shutter 219s is made of a metal material such as SUS and is formed in a disc shape. An O-ring 220c as a sealing member that abuts against the lower end of the manifold 209 is provided on the upper surface of the shutter 219s. The opening and closing operation (lifting operation, rotation operation, etc.) of the shutter 219s is controlled by a shutter opening and closing mechanism 115s.

[0085] The susceptor 217 as a substrate support is configured to support multiple wafers 200, for example, 25 to 200 wafers, in a horizontal posture with their centers aligned with each other and arranged in multiple segments in the vertical direction, that is, arranged at intervals. The susceptor 217 is made of a heat-resistant material such as quartz or SiC. A heat insulating plate 218 made of a heat-resistant material such as quartz or SiC is supported in multiple segments at the lower part of the susceptor 217.

[0086] A temperature sensor 263 as a temperature detector is provided in the reaction tube 203. Based on the temperature information detected by the temperature sensor 263, the energization state of the heater 207 is adjusted so that the temperature in the processing chamber 201 becomes a desired temperature distribution. The temperature sensor 263 is provided along the inner wall of the reaction tube 203.

[0087] As Figure 3 shown, the controller 121 as a control unit (control mechanism) is configured in the form of a computer having a CPU (Central Processing Unit), a RAM (Random Access Memory), 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 perform data exchange with the CPU 121a via an internal bus 121e. An input / output device 122 configured in the form of a touch panel or the like is connected to the controller 121.

[0088] The storage device 121c is composed of, for example, a flash memory, an HDD (Hard Disk Drive), an SSD (Solid State Drive), etc. A control program for controlling the operation of the substrate processing apparatus, process recipes including steps, conditions, etc. of substrate processing described later are stored in the storage device 121c in a readable manner. The process recipe is obtained by combining the steps in the substrate processing described later in such a way that the controller 121 can execute them and obtain a specified result, and functions as a program. Hereinafter, the process recipe, the control program, etc. will also be simply referred to as programs. In addition, the process recipe will also be simply referred to as a recipe. In this specification, when the term "program" is used, it may include only the recipe, only the control program, or both the recipe and the program. The RAM 121b is configured as a memory area (working area) that temporarily holds programs, data, etc. read by the CPU 121a.

[0089] The I / O port 121d is connected to the MFCs 241a to 241f, valves 243a to 243f, pressure sensor 245, APC valve 244, vacuum pump 246, temperature sensor 263, heater 207, rotation mechanism 267, boat elevator 115, shutter opening and closing mechanism 115s, and the like.

[0090] The CPU 121a is configured to read a control program from the storage device 121c and execute it, and to read a recipe from the storage device 121c in response to input of an operation command from the input / output device 122. The CPU 121a is configured to control, according to the contents of the read recipe, the flow rate adjustment operation of various gases by the MFCs 241a to 241f, the opening and closing operation 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 wafer boat 217 by the rotation mechanism 267, the lifting and lowering operation of the wafer boat 217 by the wafer boat elevator 115, the opening and closing operation of the shutter 219s by the shutter opening and closing mechanism 115s, and the like.

[0091] The controller 121 can be configured by installing the above-mentioned program stored in the external storage device 123 on a computer. The external storage device 123 includes, for example, a disk such as an HDD, an optical disk such as a CD, an optical disk such as an MO, a semiconductor memory such as a USB memory, an SSD, etc. The storage device 121c and the external storage device 123 are configured in the form of a computer-readable recording medium. Hereinafter, they are also referred to as recording media. In this specification, when the term recording medium is used, there is a case where only the storage device 121c is included, a case where only the external storage device 123 is included, or a case where both the storage device 121c and the external storage device 123 are included. It should be noted that the provision of the program to the computer can also be carried out without using the external storage device 123, using a communication mechanism such as the Internet or a dedicated line.

[0092] (2) Substrate processing step

[0093] Main Use Figure 4 , Figure 5 (a)~ Figure 5 (k) describes the following etching process sequence example, that is, the gas supply sequence example in the etching process: using the above-mentioned substrate processing apparatus, as a process of manufacturing a semiconductor device, a base 200a as a first film exposed on the surface of a wafer 200 as a substrate is etched. In the following description, the operation of each part constituting the substrate processing apparatus is controlled by the controller 121.

[0094] exist Figure 4 In the gas supply sequence shown,

[0095] The substrate 200a is etched by performing the following steps A and B non-simultaneously for a predetermined number of times (n times, where n is an integer greater than 1):

[0096] Step A, in which a first modified layer 200b is formed on at least a portion of a base 200a (as a first film) exposed on a surface of the wafer 200 by supplying a first gas to the wafer 200; and

[0097] Step B, wherein a second gas having a molecular structure different from that of the first gas is supplied to the chip 200, thereby generating an etching species by at least one of reacting the second gas with the first modified layer 200b and activating the first modified layer 200b using the second gas, and etching at least a portion of the substrate 200a using the etching species.

[0098] exist Figure 4 In the gas supply sequence shown, each step (ie, step A and step B) is performed in a non-plasma atmosphere.

[0099] In this specification, for convenience, the above-mentioned processing sequence may be described as follows. The same notation is also used in the following description of the modified examples.

[0100] (1st gas → 2nd gas) × n

[0101] In this specification, the term "wafer" may be used to refer to the wafer itself or to refer to a laminate of a wafer and a layer or film formed on the surface thereof. In this specification, the term "surface of a wafer" may be used to refer to the surface of a wafer itself or to refer to the surface of a layer or the like formed on a wafer. In this specification, "a layer is formed on a wafer" may be used to refer to a layer formed directly on the surface of the wafer itself or to refer to a layer formed on a layer or the like formed on a wafer. In this specification, the term "substrate" may be used in the same manner as the term "wafer".

[0102] In addition, in this specification, the term "substrate" may be used to refer to the wafer itself or to refer to a layer or film formed on the surface of the wafer. In this specification, the term "surface of the substrate" may be used to refer to the surface of the wafer itself or to refer to the surface of a layer or the like formed on the surface of the wafer. In this specification, "a layer is formed on the surface of the substrate" may be used to refer to a layer formed directly on the surface of the wafer itself or to refer to a layer formed on the surface of the layer or the like formed on the surface of the wafer.

[0103] (Wafer filling and wafer boat loading)

[0104] When a plurality of wafers 200 are loaded into the wafer boat 217 (wafer loading), the shutter 219s is moved by the shutter opening and closing mechanism 115s, and the lower end opening of the manifold 209 is opened (shutter opening). Figure 1 As shown, the wafer boat 217 supporting a plurality of wafers 200 is lifted by the wafer boat elevator 115 and carried into the processing chamber 201 (wafer boat loading). In this state, the sealing cover 219 is in a state of sealing the lower end of the manifold 209 via the O-ring 220b. It should be noted that the state is that the base 200a (i.e., the object of etching treatment) as the first film is exposed on the surface of the wafer 200. The base 200a includes, for example, a silicon-based nitrogen-containing film such as a silicon nitride film (SiN film).

[0105] (Pressure regulation and temperature regulation)

[0106] The vacuum pump 246 performs vacuum exhaust (decompression exhaust) so that the space in the processing chamber 201, that is, the space where the wafer 200 is located, reaches a desired pressure (vacuum degree). At this time, the pressure in the processing chamber 201 is measured by the pressure sensor 245, and the APC valve 244 is feedback-controlled based on the measured pressure information. In addition, the heater 207 performs heating so that the wafer 200 in the processing chamber 201 reaches a desired processing temperature. At this time, the power supply status to the heater 207 is feedback-controlled based on the temperature information detected by the temperature sensor 263 so that the processing chamber 201 reaches a desired temperature distribution. In addition, the rotation of the wafer 200 by the rotation mechanism 267 is started. The exhaust in the processing chamber 201, the heating and rotation of the wafer 200 are all continuously performed until at least the processing of the wafer 200 is completed.

[0107] (Etching treatment)

[0108] After that, the following steps A and B are performed non-simultaneously and cyclically for a prescribed number of times.

[0109] [Step A]

[0110] In step A, a first gas is supplied to the wafer 200 in the processing chamber 201 , that is, the wafer 200 with the base 200 a (first film) exposed on the surface.

[0111] Specifically, the valve 243a is opened to allow the first gas to flow into the gas supply pipe 232a. The first gas is flow-regulated by the MFC 241a, supplied into the processing chamber 201 through the nozzle 249a, flows on the surface of the wafer 200, and is exhausted from the exhaust port 231a. At this time, the first gas is supplied to the wafer 200. In addition, at this time, the valves 243d to 243f may be opened to supply inactive gases into the processing chamber 201 through the nozzles 249a to 249c, respectively.

[0112] By supplying the first gas to the wafer 200 under the conditions described below, the surface of the substrate 200a can be uniformly modified. Figure 5 As shown in (a) of FIG. 1 , when the first gas 10 is supplied to the wafer 200 having the base 200a exposed on the surface, the first gas 10 is uniformly adsorbed within the surface of the base 200a to form the first modified layer 200b.

[0113] It should be noted that the first modified layer 200b is formed by at least one of physically adsorbing or chemically adsorbing at least a portion of the molecules of the first gas 10 on at least a portion of the surface of the substrate 200a (hereinafter, also referred to as modification based on adsorption), and generating a compound by chemical reaction between at least a portion of the molecules of the first gas 10 and atoms or molecules of at least a portion of the surface of the substrate 200a (hereinafter, also referred to as modification based on compound generation). That is, in this step, the surface of the substrate 200a can be modified by modification based on adsorption and / or modification based on compound generation using the first gas 10. Figure 5 In (a), as an example, the first modified layer 200b formed by adsorbing at least a part of the molecules of the first gas 10 on at least a part of the surface of the base 200a is shown.

[0114] In the modification based on adsorption, the modified portion of the substrate 200a (i.e., the portion where the first modified layer 200b is formed) becomes a base for the etching species generated in step B described later. Therefore, the amount of etching species generated in step B can be controlled based on the amount of the first gas adsorbed on the surface of the substrate 200a. Similarly, in the modification based on compound generation, the modified portion of the substrate 200a (i.e., the portion where the first modified layer 200b is formed) also becomes a base for the etching species generated in step B described later. Therefore, the amount of etching species generated in step B can be controlled based on the amount of the compound generated on the surface of the substrate 200a. Furthermore, under the conditions described later, the first modified layer 200b can be uniformly formed in the surface of the substrate 200a, thereby enabling the etching species to be uniformly generated in the surface of the substrate 200a in step B described later.

[0115] It should be noted that, depending on the processing conditions, the reaction for forming the first modified layer 200b can also be made self-limiting. That is, depending on the processing conditions, the modification reaction based on adsorption can also be saturated, and the modification reaction based on compound generation can also be saturated. By saturating the reaction for forming the first modified layer 200b, the first modified layer 200b can be formed more uniformly within the surface of the substrate 200a. And, thereby, in step B described later, etching species can be generated more uniformly within the surface of the substrate 200a.

[0116] After the formation of the first modified layer 200b on the surface of the substrate 200a is completed, the valve 243a is closed to stop the supply of the first gas into the processing chamber 201. Then, the processing chamber 201 is evacuated to remove the gas remaining in the processing chamber 201 from the processing chamber 201. At this time, the valves 243d to 243f may be opened to supply an inactive gas into the processing chamber 201 through the nozzles 249a to 249c. The inactive gas supplied from the nozzles 249a to 249c acts as a purge gas, thereby purging the processing chamber 201. The purge with the inactive gas may not be performed. Through the above-mentioned purge, the first modified layer 200b remains on the surface of the substrate 200a, and the first gas 10, etc. that is not adsorbed on the wafer 200 is removed.

[0117] The processing conditions when the first gas is supplied in step A may be exemplified as follows:

[0118] Treatment temperature: 25 to 400°C, preferably 50 to 250°C

[0119] Processing pressure: 1 to 13300 Pa, preferably 50 to 2660 Pa

[0120] First gas supply flow rate: 1 to 5000 sccm, preferably 50 to 2000 sccm

[0121] First gas supply time: 1 to 3000 seconds, preferably 10 to 1200 seconds

[0122] Inert gas supply flow rate (each gas supply pipe): 100 to 5000 sccm, preferably 100 to 3000 sccm.

[0123] Here, the expression of a numerical range such as "25 to 400°C" in this specification indicates that the lower limit and the upper limit are included in the range. Thus, for example, "25 to 400°C" means "above 25°C and below 400°C". The same applies to other numerical ranges. It should be noted that the processing temperature indicates the temperature of the wafer 200, and the processing pressure indicates the pressure in the processing chamber 201. The same applies to the following description.

[0124] Under the above-mentioned processing conditions, the first modified layer 200b can be formed at a practical formation rate by setting the processing temperature to 25° C. or more, preferably 50° C. or more. In addition, under the above-mentioned processing conditions, the first modified layer 200b can be uniformly formed in the surface of the substrate 200a while suppressing the first film (substrate 200a) from being directly etched by the first gas by setting the processing temperature to 400° C. or less, preferably 250° C. or less.

[0125] It should be noted that in this step, the first gas can be supplied to the wafer 200 under conditions that can saturate the reaction for forming the first modified layer 200b. As a result, the first modified layer 200b can be formed more uniformly in the surface of the substrate 200a. For example, the reaction for forming the first modified layer 200b can be saturated by setting the processing temperature to a predetermined temperature of 250°C or less, preferably 200°C or less, and more preferably 150°C or less. It should be noted that even when such a processing temperature is set, the reaction for forming the first modified layer 200b can be made unsaturated by adjusting conditions other than the processing temperature (for example, shortening the first gas supply time, reducing the processing pressure, etc.).

[0126] It should be noted that the above-mentioned processing conditions can also be said to be conditions under which it is difficult for the etching reaction of the substrate 200a to continue when the first gas exists alone (i.e., when the first gas is supplied alone to the wafer 200 exposed to the substrate 200a, the same applies hereinafter). In addition, the above-mentioned processing conditions are also conditions under which it is difficult for the etching reaction of the substrate 200a to continue when the second gas exists alone (i.e., when the second gas is supplied alone to the wafer 200 exposed to the substrate 200a, the same applies hereinafter).

[0127] The treatment conditions for purging with an inert gas in step A may be exemplified as follows:

[0128] Treatment temperature: 25 to 400°C, preferably 50 to 250°C

[0129] Processing pressure: 1 to 13300 Pa, preferably 50 to 1330 Pa

[0130] Inert gas supply flow rate (each gas supply pipe): 100 to 5000 sccm, preferably 500 to 3000 sccm

[0131] Inert gas supply time: 1 to 600 seconds, preferably 10 to 120 seconds.

[0132] The first gas used in step A is not particularly limited, and any gas that can modify the surface of the substrate 200 a (first film) may be used.

[0133] As the first gas, for example, there can be mentioned silicon (Si)-containing gas, metal-containing gas, oxygen (O)-containing gas, nitrogen (N) and hydrogen (H)-containing gas, boron (B)-containing gas, phosphorus (P)-containing gas, halogen-containing gas, etc., and more than one of them can be used.

[0134] As the Si-containing gas cited as an example of the first gas, for example, an aminosilane-based gas which is a gas containing Si and an amino group can be used.

[0135] Here, an amino group is a functional group in which one or two hydrocarbon groups containing one or more carbon (C) atoms are coordinated to one nitrogen (N) atom (hereinafter referred to as NH 2 One or both of the H of the amino group represented by is substituted with a hydrocarbon group containing one or more C atoms). In the case where one N is coordinated with two hydrocarbon groups constituting a part of the amino group, the two hydrocarbon groups may be the same hydrocarbon group or different hydrocarbon groups. The hydrocarbon group may contain a single bond like an alkyl group, or an unsaturated bond such as a double bond or a triple bond. The amino group may also have a cyclic structure. The amino group is bonded to Si, which is the central atom of the aminosilane molecule, so the amino group in the aminosilane may also be referred to as a ligand or an amino ligand. Aminosilane-based gases may also contain hydrocarbon groups in addition to Si and amino groups. The hydrocarbon group may contain a single bond like an alkyl group, or an unsaturated bond such as a double bond or a triple bond. The hydrocarbon group may also have a cyclic structure. The hydrocarbon group may also be bonded to Si, which is the central atom of the aminosilane molecule, in which case the hydrocarbon group in the aminosilane may also be referred to as a ligand or a hydrocarbon ligand. In the case where the hydrocarbon group is an alkyl group, the hydrocarbon group may also be referred to as an alkyl ligand. Hereinafter, an alkyl group may be represented by R.

[0136] As the aminosilane-based gas, for example, dimethylaminotrimethylsilane (CH 3 ) 2 NSi(CH 3 ) 3 , abbreviation: DMATMS) gas, diethylaminotrimethylsilane ((C 2 H 5 ) 2 NSi(CH 3 ) 3 , DEATMS) gas, diethylaminotriethylsilane ((C 2 H 5 ) 2 NSi(C 2 H 5 ) 3 , DEATES) gas, dimethylaminotriethylsilane ((CH 3 ) 2 NSi(C2 H 5 ) 3 , abbreviated as: DMATES) gas, etc. It should be noted that, in addition to one amino group (dimethylamino group, diethylamino group) bonded to Si as the central atom of DMATMS, DEATMS, DEATES, DMATES, etc., three alkyl groups (methyl group, ethyl group) are also bonded. That is, DMATMS, DEATMS, DEATES, DMATES, etc. contain one amino ligand and three alkyl ligands.

[0137] As the aminosilane-based gas, in addition to the above-mentioned gases, a gas of an aminosilane compound represented by the following formula [1] can be used.

[0138] SiA x [(NB 2 ) (4-x) ][1]

[0139] In formula [1], A represents an H atom, an alkyl group or an alkoxy group, B represents an H atom or an alkyl group, and x represents an integer of 1 to 3. The alkyl group represented by A is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably an alkyl group having 1 to 4 carbon atoms. The alkyl group represented by A may be either linear or branched. Examples of the alkyl group represented by A include methyl, ethyl, n-propyl, n-butyl, isopropyl, isobutyl, sec-butyl, tert-butyl, and the like. The alkoxy group represented by A is preferably an alkoxy group having 1 to 5 carbon atoms, and more preferably an alkoxy group having 1 to 4 carbon atoms. The alkyl group in the alkoxy group represented by A is the same as the alkyl group represented by A above. When x is 2 or 3, 2 or 3 A's may be the same or different. The alkyl group represented by B is the same as the alkyl group represented by A above. In addition, 2 B's may be the same or different, and when x is 1 or 2, multiple (NB 2 ) may be the same or different. In addition, two Bs may be bonded to form a ring structure, or the formed ring structure may further have a substituent such as an alkyl group.

[0140] As the aminosilane gas represented by formula [1], for example, monoaminosilane (SiH) in which A in formula [1] is a H atom, B is an alkyl group, and x is 3 (i.e., an aminosilane compound containing one amino group in one molecule) can be used. 3 (NR 2 ), referred to as MAS) gas, wherein A in the formula [1] is a hydrogen atom, B is an alkyl group, and x is 2 (i.e., an aminosilane compound containing two amino groups in one molecule), bisaminosilane (SiH 2 (NR 2 ) 2, abbreviated as BAS) gas, triaminosilane (SiH(NR) wherein A in formula [1] is a hydrogen atom, B is an alkyl group, and x is 1 (an aminosilane compound containing three amino groups in one molecule) 2 ) 3 , abbreviated as: TAS) gas. Among them, MAS gas is preferably used as the aminosilane gas. By using MAS gas as the first gas, the surface of the substrate 200a can be modified more uniformly and sufficiently in step A.

[0141] Examples of the MAS gas include ethylmethylaminosilane (SiH 3 [N(CH 3 )(C 2 H 5 )]) gas, dimethylaminosilane (SiH 3 [N(CH 3 ) 2 ]) gas, diisopropylaminosilane (SiH 3 [N(C 3 H 7 ) 2 ]) gas, di-sec-butylaminosilane (SiH 3 [H(C 4 H 9 ) 2 ]) gas, dimethylpiperidinylsilane (SiH 3 [NC 5 H 8 (CH 3 ) 2 ]) gas, diethylpiperidinylsilane (SiH 3 [NC 5 H 8 (C 2 H 5 ) 2 ]) gas, and more than one of them can be used. In this specification, MAS gas is a gas of an aminosilane compound having one amino group in one molecule, and also includes a gas having a silane compound other than the above SiH 3 (NR 2 ) is a gas having a structure other than the structure represented by the formula [1]. For example, the above-mentioned DMATMS, DEATMS, DEATES, and DMATES are also aminosilane compounds containing one amino group in one molecule, so the above-mentioned gases can also be contained in the MAS gas. It should be noted that the above-mentioned DMATMS, DEATMS, DEATES, and DMATES are aminosilane compounds in which A in the formula [1] is an alkyl group, B is an alkyl group, and x is 3.

[0142] As the Si-containing gas cited as an example of the first gas, for example, a halogenated silane gas as a gas containing Si and a halogenated group can be used. As the halogenated group, it is preferred that at least one of a fluorine group, a chlorine group, a bromine group, and an iodine group be contained, and it is more preferred that a chlorine group be contained. That is, it is preferred that the halogenated silane gas contain at least any one of fluorine (F), chlorine (Cl), bromine (Br), and iodine (I), and it is more preferred that Cl be contained. As the halogenated silane gas, for example, hexachlorodisilane (Si 2 Cl 6 ) gas, tetrachlorosilane (SiCl 4 ) gas, trichlorosilane (SiHCl 3 ) gas, dichlorosilane (SiH 2 Cl 2 ) gas, monochlorosilane (SiH 3 Cl) gas and other chlorosilane gases, silicon tetrafluoride (SiF 4 ) gas, difluorosilane (SiH 2 F 2 ) gases such as fluorosilane gases, silicon tetrabromide (SiBr 4 ) gas, dibromosilane (SiH 2 Br 2 ) gas, such as bromosilane gas, silicon tetraiodide (SiI 4 ) gas, diiodosilane (SiH 2 I 2 ) gas and other iodosilane gases, etc., and one or more thereof can be used.

[0143] In addition, as the halogenated silane gas, an alkyl halogenated silane gas can also be used. As the alkyl halogenated silane gas, for example, dimethyldichlorosilane ((CH 3 ) 2 SiCl 2 ) gas, trimethylchlorosilane ((CH 3 ) 3 SiCl) gas, alkylchlorosilane gases, dimethyldifluorosilane ((CH 3 ) 2 SiF 2 ) gas, trimethylsilyl fluoride ((CH 3 ) 3 SiF) gas, alkyl fluorosilane gases, dimethyldibromosilane ((CH 3 ) 2 SiBr 2 ) gas, trimethylsilane bromide ((CH 3 ) 3 SiBr) gas, alkyl bromide silane gas, dimethyl diiodosilane ((CH 3 ) 2SiI 2 ) gas, trimethylsilyl iodide ((CH 3 ) 3 Alkyl iodide silane-based gases such as SiI) gas, etc., and one or more thereof can be used.

[0144] As the Si-containing gas cited as an example of the first gas, for example, a gas containing Si and H, that is, a silicon hydride gas can be used. As the silicon hydride gas, for example, monosilane (SiH 4 ) gas, disilane (Si 2 H 6 ) gas, trisilane (Si 3 H 8 ) gas, tetrasilane (SI 4 H 10 ) gases, etc., more than one of which can be used.

[0145] As the metal-containing gas cited as an example of the first gas, for example, a gas containing a metal and an amino group, a gas containing a metal and a halogenated group, etc. can be used. As the halogenated group, it is preferred to contain at least any one of a fluorine group, a chlorine group, a bromine group, and an iodine group, and it is more preferred to contain a chlorine group. That is, it is preferred that the gas containing a metal and a halogenated group contains at least any one of F, Cl, Br, and I, and it is more preferred to contain Cl. As the above gas, for example, tetrakis(dimethylamino)titanium (Ti[N(CH 3 ) 2 ] 4 ) gas, tetrakis(diethylamino)titanium(Ti[N(C 2 H 5 ) 2 ] 4 ) gas, titanium tetrafluoride (TiF 4 ) gas, titanium tetrachloride (TiCl 4 ) gas, titanium tetrabromide (TiBr 4 ) gas, titanium tetraiodide (TiI 4 ) gases, etc., more than one of which can be used.

[0146] Examples of the O-containing gas used as the first gas include oxygen (O 2 ) gas, nitric oxide (NO) gas, nitrogen dioxide (NO 2 ) gas, nitrous oxide (N 2 O) gas, ozone (O 3 ) gas, water vapor (H 2 O gas), hydrogen peroxide (H 2 O 2 ) Gas, O 2 Gas+H 2 Gas, O3 Gas+H 2 Gases, etc., one or more of them can be used.

[0147] Examples of the N and H-containing gas that can be used as the first gas include ammonia (NH 3 ) gas, hydrazine (N 2 H 4 ) gas, diazine (N 2 H 2 ) gas, monomethylhydrazine (CH 3 HN 2 H 2 ) gas, dimethylhydrazine ((CH 3 ) 2 N 2 (CH 3 )H) gas, trimethylhydrazine ((CH 3 ) 3 N 2 H 2 ) gases, etc., and more than one of them can be used.

[0148] As the B-containing gas and P-containing gas cited as an example of the first gas, for example, a B- and H-containing gas, a P- and H-containing gas, etc. can be used. As the above gas, diborane (B 2 H 6 ) gas, phosphine (PH 3 ) gases, etc., and more than one of them can be used.

[0149] As the halogen-containing gas given as an example of the first gas, for example, a C and F-containing gas, a Cl and F-containing gas, a F-containing gas, a N and F-containing gas, a N, F and O-containing gas, a N, Cl and O-containing gas, etc. can be given. As the above gas, for example, tetrafluoromethane (CF 4 ) gas, hexachloroethane (C 2 F 6 ) gas, octafluoropropane (C 3 F 8 ) gas, chlorine monofluoride (ClF) gas, chlorine trifluoride (ClF 3 ) gas, fluorine (F 2 ) gas, nitrogen trifluoride (NF 3 ) gas, nitrosyl fluoride (FNO) gas, trifluoronitrosyl (F 3 NO) gas, nitroxyl fluoride (FNO 2 ) gas, nitrosyl chloride (ClNO) gas, NF 3 Gas + NO gas, F 2 gas+NO gas, ClF gas+NO gas, ClF 3gas+NO gas, etc., one or more of them can be used.

[0150] It should be noted that in this manual, “NF 3 The combined description of two gases such as "gas + NO gas" indicates NF 3 When supplying a mixed gas, the two gases may be mixed (premixed) in a supply pipe and then supplied to the processing chamber 201, or the two gases may be supplied to the processing chamber 201 from different supply pipes and mixed (postmixed) in the processing chamber 201.

[0151] In addition, for a gas that is difficult to store, such as FNO gas, it is preferable to use F 2 The FNO gas is mixed with the NO gas in a supply pipe and a nozzle provided in the substrate processing device, and the FNO gas generated in the supply pipe and the nozzle is supplied to the processing chamber 201. In addition, for example, a gas mixing chamber may be provided in the substrate processing device so that the F 2 The gas and the NO gas are mixed in the gas mixing chamber to generate FNO gas, and the FNO gas generated in the gas mixing chamber is supplied into the processing chamber 201 through the supply pipe and the nozzle.

[0152] As the inert gas used in step A, in addition to nitrogen (N 2 ) gas, for example, a rare gas such as argon (Ar) gas, helium (He) gas, neon (Ne) gas, xenon (Xe) gas, etc. can be used. As an inert gas, the same gas can also be used in each step described later.

[0153] [Step B]

[0154] In step B, after step A is completed, the second gas is supplied to the wafer 200 in the processing chamber 201, that is, to the wafer 200 having the first modified layer 200b formed on the surface of the base 200a. As described above, the second gas has a molecular structure different from that of the first gas.

[0155] Specifically, the valve 243b is opened to allow the second gas to flow into the gas supply pipe 232b. The second gas is flow-regulated by the MFC 241b, supplied into the processing chamber 201 through the nozzle 249b, flows on the surface of the wafer 200, and is exhausted from the exhaust port 231a. At this time, the second gas is supplied to the wafer 200. In addition, at this time, the valves 243d to 243f may be opened to supply inactive gas into the processing chamber 201 through the nozzles 249a to 249c, respectively.

[0156] By supplying the second gas to the wafer 200 under the conditions described below, etching species are generated from the first modified layer 200b formed on the surface of the substrate 200a. Specifically, Figure 5 As shown in (b), if the second gas 20 is supplied to the wafer 200 having the first modified layer 200b formed on the surface of the substrate 200a, as shown in Figure 5 As shown in (c), the first modified layer 200b (here, the first gas 10 adsorbed on the surface of the base 200a) is activated by the second gas 20 to generate etching species 200c.

[0157] It should be noted that the etching seed 200c is generated by at least one of reacting the second gas with the first modified layer 200b and activating the first modified layer 200b using the second gas. Hereinafter, the case where the etching seed 200c is generated like the former will also be referred to as reaction-based etching seed generation. Hereinafter, the case where the etching seed 200c is generated like the latter will also be referred to as activation-based etching seed generation. That is, in this step, the etching seed 200c is generated on the surface of the substrate 200a by reaction-based etching seed generation and / or activation-based etching seed generation. It should be noted that the etching seed 200c is generated with the first modified layer 200b formed in a layer as a matrix and exists in a layered state, so the etching seed 200c can also be referred to as an etching seed-containing layer 200c, an etching seed-containing layer 200c, or simply an etching seed layer 200c. As an example, Figure 5 (c) shows etching species 200 c generated by activating the first gas 10 adsorbed on the surface of the base 200 a using the second gas 20 , that is, a layer 200 c including the etching species.

[0158] If etching seeds 200c are generated on the surface of the substrate 200a, Figure 5 As shown in (d), a portion of the surface of the substrate 200a is etched by the etching species 200c. When a portion of the surface of the substrate 200a is etched by the etching species 200c, as shown in Figure 5 As shown in (d), during the etching reaction, for example, a first product 12 is generated as a by-product. At this time, there is a case where a second product 14 is generated as a by-product in addition to the first product 12. Hereinafter, a case where the first product 12 and the second product 14 are generated as by-products will be described.

[0159] When a portion of the surface of the substrate 200a is etched by the etching species 200c, if the first product 12 and the second product 14 are generated as by-products, for example, Figure 5As shown in (e), the first product 12 is detached from the surface of the substrate 200a. At this time, the second product 14 remains on the surface of the substrate 200a. It should be noted that at this time, there is also a case where a part of the second product 14 is detached from the surface of the substrate 200a. In addition, at this time, there is also a case where the second product 14 repeatedly detaches from the surface of the substrate 200a and adsorbs to the surface of the substrate 200a. As an example, Figure 5 (e) shows that the second product 14 is detached from the surface of the substrate 200a and adsorbed onto the surface of the substrate 200a. Figure 5 As shown in (f), the surface of the substrate 200a where a part of the surface is etched is uniformly left and / or adsorbed.

[0160] In this way, if the second product 14 is uniformly left and / or adsorbed on the surface of the substrate 200a whose surface is partially etched, Figure 5 As shown in (g), at least one of the second product 14, the second gas 20, and the substrate 200a whose surface is partially etched reacts to form a second modified layer 200d on the surface of the substrate 200a whose surface is partially etched. For example, the second modified layer 200d is formed by the reaction of the second product 14 and the second gas 20 with the substrate 200a whose surface is partially etched. In addition, for example, the second modified layer 200d is formed by the reaction of the second product 14, the second gas 20, and the substrate 200a whose surface is partially etched.

[0161] When the substrate 200a is a silicon-based nitrogen-containing film such as a SiN film, and at least one of the first gas and the second gas is the above-mentioned halogen-containing gas, the first modified layer 200b may become an adsorption layer of the halogen-containing gas. In this case, a substance containing at least one of nitrogen, halogen, and silicon may be generated as the first product 12, and a substance containing at least one of nitrogen, oxygen, silicon, and halogen may be generated as the second product 14. In this case, the second modified layer 200d may become a substance containing silicon, oxygen, and halogen.

[0162] Note that, as described above, in this step, the second product 14 may not be produced as a by-product. In this case, the second modified layer 200d is not formed on the surface of the base 200a whose surface is partially etched.

[0163] As described above, in this step, the etching species 200c is generated using the second gas with the first modified layer 200b as a matrix, and the generated etching species 200c is used to etch a portion of the surface of the substrate 200a. This process can improve the controllability of the etching amount when etching the substrate 200a.

[0164] This is because the present method does not use etching gas to directly etch the film to be etched (here, the substrate 200a), and is therefore not easily affected by the distribution of gas partial pressure (≈(Japanese: ≒) supply amount) caused by the shape of the film to be etched.

[0165] In this method, the amount of etching seeds 200c generated in step B is controlled, so that the etching amount of the substrate 200a can be controlled. In addition, the amount of etching seeds 200c can be controlled based on the amount of adsorption of the first gas to the surface of the substrate 200a in step A and the amount of compounds generated on the surface of the substrate 200a in step A. That is, the amount of etching seeds 200c can be controlled based on the amount of the first modified layer 200b formed in step A, that is, the thickness of the first modified layer 200b, that is, the modification amount of the substrate 200a in step A. In addition, in step A, by uniformly forming the first modified layer 200b in the surface of the substrate 200a, the etching seeds can be uniformly generated in the surface of the substrate 200a in step B, and the uniformity of the etching amount of the substrate 200a can be improved. And, thereby, a conformal etching process can be performed.

[0166] It should be noted that, as described above, in step A, the reaction for forming the first modified layer 200b can also be made self-limiting. That is, in step A, the modification reaction based on adsorption can also be saturated, and the modification reaction based on compound generation can also be saturated. By saturating the reaction for forming the first modified layer 200b, the first modified layer 200b can be formed more uniformly within the surface of the substrate 200a. Thus, in step B, etching species can be generated more uniformly within the surface of the substrate 200a, and the uniformity of the etching amount of the substrate 200a can be further improved. And, thereby, conformal etching treatment can also be implemented. It should be noted that as a method for saturating the modification reaction, the method for saturating the modification reaction based on adsorption can further improve the controllability of the etching amount compared to the method for saturating the modification reaction based on compound generation.

[0167] It should be noted that, as described above, the amount of etching species 200c generated in step B depends on the amount of the first modified layer 200b formed in step A. That is, in step B, after the generation reaction of the etching species 200c based on the first modified layer 200b is completed, the etching species 200c will not be generated even if the second gas is continuously supplied. That is to say, in step B, after the entire first modified layer 200b is converted into the etching species, or after the component that converts the first modified layer 200b into the etching species disappears, the etching species 200c will not be generated even if the second gas is continuously supplied. In this way, in this method, not only the modification reaction in step A can be saturated, but also the generation reaction of the etching species 200c in step B can be saturated. It should be noted that the modification reaction in step A and / or the generation reaction of the etching species 200c in step B can also be made unsaturated, thereby enabling the etching amount to be more finely and minutely controlled.

[0168] After the etching of a portion of the surface of the substrate 200a using the etching species 200c is completed and the second modified layer 200d is formed on the surface of the substrate 200a whose surface is partially etched, the valve 243b is closed to stop the supply of the second gas 20 to the processing chamber 201. In addition, the processing chamber 201 is vacuum-exhausted by the same processing step as the purging in step A, and the gas and the like remaining in the processing chamber 201 are removed from the processing chamber 201. At this time, the valves 243d to 243f may be opened, and an inactive gas may be supplied to the processing chamber 201 through the nozzles 249a to 249c, and the purging using the inactive gas may be performed in the same manner as step A. Through the above-mentioned purging, the second modified layer 200d remains on the surface of the substrate 200a whose surface is partially etched, and the second gas and the like remaining in the processing chamber 201 are removed.

[0169] The processing conditions when the second gas is supplied in step B may be exemplified as follows:

[0170] Treatment temperature: 25 to 400°C, preferably 50 to 250°C

[0171] Processing pressure: 1 to 13300 Pa, preferably 50 to 2660 Pa

[0172] Second gas supply flow rate: 1 to 5000 sccm, preferably 50 to 2000 sccm

[0173] Second gas supply time: 1 to 3000 seconds, preferably 10 to 1200 seconds

[0174] Inert gas supply flow rate (each gas supply pipe): 100 to 5000 sccm, preferably 100 to 3000 sccm.

[0175] Under the above-mentioned processing conditions, by setting the processing temperature to 25° C. or higher, preferably 50° C. or higher, it is possible to achieve generation of etching species based on reaction and / or generation of etching species based on activation. In addition, by setting the processing temperature to 400° C. or lower, preferably 250° C. or lower under the above-mentioned processing conditions, it is possible to promote etching of the first film (substrate 200a) by the etching species 200c while suppressing direct etching of the first film (substrate 200a) by the second gas 20.

[0176] It should be noted that the above processing conditions can also be said to be conditions under which the etching reaction of the substrate 200a is difficult to continue when the second gas exists alone. In addition, the above processing conditions are also conditions under which the etching reaction of the substrate 200a is difficult to continue when the first gas exists alone.

[0177] It should be noted that in this step, the second gas is supplied to the wafer 200 under the condition that the reaction between the second gas and the first modified layer 200b occurs dominantly (is in a dominant position) compared with the reaction between the second gas and the substrate 200a. As a result, it is possible to promote the generation of etching species that contribute to the etching of the substrate 200a while suppressing the direct etching of the substrate 200a by the second gas. As a result, the controllability of the etching amount when etching the substrate 200a can be further improved. Under the above-mentioned processing conditions, for example, by making the processing temperature a predetermined temperature of 400°C or less, preferably 250°C or less, the second gas is supplied to the wafer 200 under the condition that the reaction between the second gas and the first modified layer 200b occurs dominantly compared with the reaction between the second gas and the substrate 200a.

[0178] In addition, in this step, the second gas may be supplied to the wafer 200 under the condition that the reaction between the second gas and the first modified layer 200b proceeds, while the reaction between the second gas and the substrate 200a does not proceed. Thus, it is possible to reliably suppress the direct etching of the substrate 200a by the second gas while promoting the generation of etching species that contribute to the etching of the substrate 200a. As a result, the controllability of the etching amount when etching the substrate 200a can be further improved. Under the above-mentioned processing conditions, for example, by making the processing temperature a predetermined temperature of 250° C. or less, preferably 200° C. or less, and more preferably 150° C. or less, it is possible to supply the second gas to the wafer 200 under the condition that the reaction between the second gas and the first modified layer 200b proceeds, while the reaction between the second gas and the substrate 200a does not proceed.

[0179] It should be noted that in this step, the second gas is supplied to the wafer 200 under the condition that activation of the first modified layer 200b by the second gas occurs dominantly compared to activation of the substrate 200a by the second gas. As a result, it is possible to promote the generation of etching species that contribute to etching of the substrate 200a while suppressing direct etching of the substrate 200a by the second gas. As a result, the controllability of the etching amount when etching the substrate 200a can be further improved. Under the above-mentioned processing conditions, for example, by making the processing temperature a predetermined temperature of 400° C. or less, preferably 250° C. or less, it is possible to supply the second gas to the wafer 200 under the condition that activation of the first modified layer 200b by the second gas occurs dominantly compared to activation of the substrate 200a by the second gas.

[0180] In addition, in this step, the second gas may be supplied to the wafer 200 under the condition that the activation of the first modified layer 200b by the second gas is performed, but the activation of the substrate 200a by the second gas is not performed. Thus, it is possible to promote the generation of etching species that contribute to the etching of the substrate 200a while reliably suppressing the direct etching of the substrate 200a by the second gas. As a result, the controllability of the etching amount when etching the substrate 200a can be further improved. Under the above-mentioned processing conditions, for example, by making the processing temperature a predetermined temperature of 250° C. or less, preferably 200° C. or less, and more preferably 150° C. or less, it is possible to supply the second gas to the wafer 200 under the condition that the activation of the first modified layer 200b by the second gas is performed, but the activation of the substrate 200a by the second gas is not performed.

[0181] In addition, in this step, the second gas is supplied to the wafer 200 under the condition that the etching of the substrate 200a by the etching species is performed more than the reaction of the second gas with the substrate 200a. As a result, it is possible to suppress the direct etching of the substrate 200a by the second gas, and make the etching reaction of the substrate 200a by the etching species occur dominantly. As a result, the controllability of the etching amount when etching the substrate 200a can be further improved. Under the above-mentioned processing conditions, for example, by making the processing temperature a predetermined temperature of 400° C. or less, preferably 250° C. or less, it is possible to supply the second gas to the wafer 200 under the condition that the etching of the substrate 200a by the etching species is performed more than the reaction of the second gas with the substrate 200a.

[0182] In addition, the processing conditions in this step may also be such that the second gas is supplied to the wafer 200 under the condition that the etching of the substrate 200a by the etching species is performed, but the reaction of the second gas with the substrate 200a is not performed. Thus, it is possible to reliably suppress the direct etching of the substrate 200a by the second gas, and make the etching reaction of the substrate 200a by the etching species occur more dominantly. As a result, the controllability of the etching amount when etching the substrate 200a can be further improved. Under the above-mentioned processing conditions, for example, by making the processing temperature a predetermined temperature of 250° C. or less, preferably 200° C. or less, and more preferably 150° C. or less, it is possible to supply the second gas to the wafer 200 under the condition that the etching of the substrate 200a by the etching species is performed, but the reaction of the second gas with the substrate 200a is not performed.

[0183] In addition, as described above, in this step, the second gas can be supplied to the wafer 200 under the condition that the generation reaction of the etching species 200c can be saturated. For example, by making the processing temperature a predetermined temperature of 400°C or less, preferably 250°C or less, the generation reaction of the etching species 200c can be saturated. In addition, for example, even when the processing temperature is a predetermined temperature of 200°C or less, 150°C or less, the generation reaction of the etching species 200c can be saturated. It should be noted that, as described above, in this step, after the entire first modified layer 200b is converted into the etching species, or after the component of the first modified layer 200b converted into the etching species disappears, the etching species 200c is no longer generated, so the generation reaction of the etching species 200c is relatively easy to be saturated. It should be noted that even when the processing temperature is set to such a processing temperature, the generation reaction of the etching species 200c can be made unsaturated by adjusting conditions other than the processing temperature (for example, shortening the second gas supply time, reducing the processing pressure, etc.).

[0184] The following are examples of the treatment conditions for purging with an inert gas in step B:

[0185] Treatment temperature: 25 to 400°C, preferably 50 to 250°C

[0186] Processing pressure: 1 to 13300 Pa, preferably 50 to 1330 Pa

[0187] Inert gas supply flow rate (each gas supply pipe): 100 to 5000 sccm, preferably 500 to 3000 sccm

[0188] Inert gas supply time: 1 to 600 seconds, preferably 10 to 120 seconds.

[0189] The second gas used in step B is not particularly limited, and may be any gas that can react with the first modified layer 200 b and / or activate the first modified layer 200 b to generate etching species.

[0190] As the second gas, for example, a halogen-containing gas, an acetylacetone-based gas, etc. can be used. As the halogen-containing gas and the acetylacetone-based gas, for example, an I-and-F-containing gas, a B-and-Cl-containing gas, a Cl-containing gas, a H-and-Cl-containing gas, a S, O-and-Cl-containing gas, a H-and-F-containing gas, a metal-and-F-containing gas, a metal-and-Cl-containing gas, a Cl-and-F-containing gas, a F-containing gas, a N-and-F-containing gas, a N, F-and-O-containing gas, a N, Cl-and-O-containing gas, a C, H-and-O-containing gas, a C, H, F-and-O-containing gas, etc. can be used.

[0191] Examples of the gas include iodine heptafluoride (IF 7 ) gas, iodine pentafluoride (IF 5 ) gas, boron trichloride (BCl 3 ) gas, chlorine (Cl 2 ) gas, hydrogen chloride (HCl) gas, thionyl chloride (SOCl 2 ) gas, hydrogen fluoride (HF) gas, tungsten hexafluoride (WF 6 ) gas, tungsten hexachloride (WCl 6 ) gas, tungsten pentachloride (WCl 5 ) gas, chlorine monofluoride (ClF) gas, chlorine trifluoride (ClF 3 ) gas, fluorine (F 2 ) gas, nitrogen trifluoride (NF 3 ) gas, nitrosyl fluoride (FNO) gas, trifluoronitrosyl (F 3 NO) gas, nitroxyl fluoride (FNO 2 ) gas, nitrosyl chloride (ClNO) gas, acetylacetone (C 5 H 8 O 2 ) gas, hexafluoroacetylacetone (C 5 H 2 F 6 O 2 ) gases, etc., more than one of which can be used.

[0192] As described above, for a gas that is difficult to store, such as FNO gas, it is preferable to use F 2 The FNO gas is mixed with the NO gas in a supply pipe or a nozzle provided in the substrate processing apparatus to generate the FNO gas, and the FNO gas generated in the supply pipe or the nozzle is supplied to the processing chamber 201. In addition, as described above, for example, a gas mixing chamber may be provided in the substrate processing apparatus to mix the FNO gas in the gas mixing chamber. 2The gas is mixed with NO gas to generate FNO gas, and the FNO gas generated in the gas mixing chamber is supplied into the processing chamber 201 through a supply pipe and a nozzle.

[0193] [Step A after the second cycle]

[0194] As described above, in step B, there is a case where the second modified layer 200d is formed on the surface of the substrate 200a whose surface is partially etched. In this case, in step A after the second cycle, the first gas is supplied to the wafer 200 in the processing chamber 201, that is, to the wafer 200 having the second modified layer 200d formed on the surface of the substrate 200a whose surface is partially etched. The supply method and supply conditions of the first gas may be the same as those in step A above.

[0195] By supplying the first gas to the wafer 200 having the second modified layer 200d formed on the surface of the base 200a whose surface is partially etched under the above conditions, Figure 5 As shown in (h), the first gas 10 is adsorbed on the surface of the second modified layer 200d. When the first gas 10 is adsorbed on the surface of the second modified layer 200d, the first gas 10 reacts with the second modified layer 200d, as shown in FIG. Figure 5 As shown in (i), the second modified layer 200d is removed. In the process of the first gas 10 reacting with the second modified layer 200d, a product 30 is generated as a by-product and adsorbed on the surface of the substrate 200a after the second modified layer 200d is removed. There is a case where the product 30 becomes, for example, the same substance as the first product 12.

[0196] By continuing to supply the first gas 10 to the wafer 200 after the product 30 is adsorbed on the surface of the substrate 200a, Figure 5 As shown in (j), the product 30 is separated from the surface of the substrate 200a. And, after the product 30 is separated from the surface of the substrate 200a, as shown in Figure 5 As shown in (k), the surface of the substrate 200a is exposed again.

[0197] Then, by continuing to supply the first gas 10 to the wafer 200 after the substrate 200a is exposed again, Figure 5 Similarly to the state shown in (a) of FIG. 1 , the first gas 10 is adsorbed on the surface of the substrate 200a to form the first modified layer 200b. The subsequent treatment is performed in the same manner as the first cycle, and the same reaction as the first cycle occurs.

[0198] It should be noted that, when the second product 14 is not generated as a by-product in step B, the second modified layer 200d is not formed on the surface of the base 200a whose surface is partially etched. In this case, in step A after the second cycle, the same reaction as step A in the first cycle also occurs.

[0199] [Number of times the regulations are implemented]

[0200] By performing the above-mentioned step A and step B non-simultaneously, i.e., asynchronously, for a predetermined number of times (n times, where n is an integer greater than 1), the base 200a exposed on the surface of the wafer 200 can be etched to a desired depth. It is preferred that the above-mentioned cycle be repeated a plurality of times. That is, it is preferred that the thickness of the layer etched in each cycle be thinner than the desired thickness, and the above-mentioned cycle be repeated a plurality of times until the thickness of the layer removed by etching reaches the desired thickness.

[0201] (Post-purge and atmospheric pressure recovery)

[0202] After the etching process of the substrate 200a is completed, an inactive gas is supplied from the nozzles 249a to 249c as a purge gas into the processing chamber 201, and the gas is exhausted from the exhaust port 231a. Thus, the processing chamber 201 is purged, and the gas and reaction by-products remaining in the processing chamber 201 are removed from the processing chamber 201 (post-purge). After that, the atmosphere in the processing chamber 201 is replaced with an inactive gas (inactive gas replacement), and the pressure in the processing chamber 201 is restored to normal pressure (atmospheric pressure recovery).

[0203] (Wafer boat unloading and wafer removal)

[0204] The sealing cover 219 is lowered by the wafer boat elevator 115, and the lower end of the manifold 209 is opened. Then, the processed wafer 200 is carried out from the lower end of the manifold 209 to the outside of the reaction tube 203 in a state supported by the wafer boat 217 (wafer boat unloading). After the wafer boat is unloaded, the gate 219s is moved, and the lower end opening of the manifold 209 is sealed by the gate 219s with the aid of the O-ring 220c (gate closing). After being carried out to the outside of the reaction tube 203, the processed wafer 200 is taken out from the wafer boat 217 (wafer taking out).

[0205] (3) Effects of this method

[0206] According to this aspect, one or more of the following effects can be obtained.

[0207] By performing the cycle of step A and step B non-simultaneously for a predetermined number of times to etch the substrate 200a, the controllability of the etching amount of the substrate 200a can be improved. That is, instead of directly etching the substrate 200a using the first gas and the second gas, the substrate 200a is etched using the etching species 200c generated on the surface of the substrate 200a in step B. As a result, the controllability of the etching amount of the substrate 200a can be improved without being affected by the distribution of the gas partial pressure (≈supply amount) caused by the shape of the substrate 200a. In this case, the etching amount of the substrate 200a can be freely controlled by controlling the amount of the etching species 200c generated on the surface of the substrate 200a in step B. For example, the etching amount of the substrate 200a can be controlled at a level below 1 atomic layer (1 molecular layer), and can also be controlled at a level exceeding 1 atomic layer (1 molecular layer), for example, at a level of several atomic layers (several molecular layers). It should be noted that the level of etching amount below 1 atomic layer (1 molecular layer) indicates the level of etching thickness of 1 atomic layer (1 molecular layer) or less than 1 atomic layer (1 molecular layer). The level of etching amount less than 1 atomic layer (1 molecular layer) indicates the level of etching thickness less than 1 atomic layer (1 molecular layer), for example, the case where the etching amount is half an atomic layer (half a molecular layer) is equivalent to this level. It should be noted that according to the present method, the etching amount can also be controlled at a level of less than half an atomic layer (half a molecular layer), that is, half an atomic layer (half a molecular layer) or less than half an atomic layer (half a molecular layer).

[0208] For example, in a situation where the amount of gas exposure is likely to be locally reduced, such as when a 3D structure such as a groove or a hole is formed on the surface of the wafer 200, or when the substrate 200a is arranged along the shape of the surface, or when the gas partial pressure in the processing chamber 201 is not constant depending on the location, the etching amount of the substrate 200a can be finely controlled to be uniform within the in-plane range of the wafer 200 by performing a cycle of step A and step B non-simultaneously for a predetermined number of times to etch the substrate 200a. In addition, conformal etching can be performed thereby.

[0209] It should be noted that, in order to achieve the above effects, it is preferred that the cycle of step A and step B is performed non-simultaneously for a predetermined number of times under the condition that the etching reaction of the substrate 200a is difficult to continue when at least one of the first gas and the second gas exists alone. In addition, it is more preferred that the cycle of step A and step B is performed non-simultaneously for a predetermined number of times under the condition that the etching reaction of the substrate 200a is difficult to continue when the first gas and the second gas exist alone.

[0210] In step A, the portion where the first modified layer 200b is formed becomes the matrix of the etching species 200c generated on the surface of the substrate 200a in step B. Therefore, the amount of etching species 200c generated in step B, that is, the etching amount, can be controlled based on the amount of adsorption of the first gas onto the surface of the substrate 200a in step A.

[0211] For example, in step A, by making the thickness of the adsorption layer of the first gas formed on the surface of the substrate 200a (that is, the first modified layer 200b, and the same below) less than 1 atomic layer (1 molecular layer), the etching amount (etching thickness) of the substrate 200a in step B can be controlled at a level of, for example, less than 1 atomic layer (1 molecular layer). In addition, for example, by making the thickness of the adsorption layer of the first gas formed on the surface of the substrate 200a less than 1 atomic layer (1 molecular layer) in step A, the etching amount of the substrate 200a in step B can be controlled at a level of, for example, less than 1 atomic layer (1 molecular layer). In addition, for example, by making the thickness of the adsorption layer of the first gas formed on the surface of the substrate 200a more than 1 atomic layer (1 molecular layer) in step A, the etching amount of the substrate 200a in step B can be controlled at a level of, for example, more than 1 atomic layer (1 molecular layer). In addition, for example, by making the thickness of the adsorption layer of the first gas formed on the surface of the substrate 200a be several atomic layers (several molecular layers) in step A, the etching amount of the substrate 200a in step B can be controlled at the level of, for example, several atomic layers (several molecular layers).

[0212] The portion where the first modified layer 200b is formed in step A becomes the matrix of the etching species 200c generated on the surface of the substrate 200a in step B. Therefore, the amount of etching species 200c generated in step B, i.e., the etching amount, can be controlled based on the amount of the compound generated on the surface of the substrate 200a in step A.

[0213] For example, by making the thickness of the compound generated on the surface of the substrate 200a in step A less than 1 atomic layer (1 molecular layer), the etching amount (etching thickness) of the substrate 200a in step B can be controlled at a level of, for example, less than 1 atomic layer (1 molecular layer). In addition, for example, by making the thickness of the compound generated on the surface of the substrate 200a in step A less than 1 atomic layer (1 molecular layer), the etching amount of the substrate 200a in step B can be controlled at a level of, for example, less than 1 atomic layer (1 molecular layer). In addition, for example, by making the thickness of the compound generated on the surface of the substrate 200a in step A more than 1 atomic layer (1 molecular layer), the etching amount of the substrate 200a in step B can be controlled at a level of, for example, more than 1 atomic layer (1 molecular layer). In addition, for example, by making the thickness of the compound generated on the surface of the substrate 200a in step A to be several atomic layers (several molecular layers), the etching amount of the substrate 200a in step B can be controlled at the level of, for example, several atomic layers (several molecular layers).

[0214] In step A, the reaction for forming the first modified layer 200b, i.e., the modification reaction, can be saturated. Thus, in step A, the first modified layer 200b can be formed more uniformly within the surface of the substrate 200a. As a result, in step B, etching species can be generated more uniformly within the surface of the substrate 200a, and the uniformity of the etching amount of the substrate 200a can be further improved. Moreover, conformal etching treatment can be further implemented thereby. It should be noted that, as a method for saturating the modification reaction, the method for saturating the modification reaction based on adsorption can further improve the controllability of the etching amount compared to the method for saturating the modification reaction based on compound generation. For example, by saturating the modification reaction based on adsorption in step A, it is easy to make the thickness of the adsorption layer of the first gas formed on the surface of the substrate 200a less than 1 atomic layer (1 molecular layer).

[0215] In step B, not only a portion of the surface of the substrate 200a can be etched, but also a second modified layer 200d that can be removed using the first gas can be formed on the surface of the substrate 200a after the portion of the surface is etched. In this case, by supplying the first gas to the wafer 200 in step A after the second cycle, the second modified layer 200d can be removed, and the first modified layer 200b can be formed on the surface of the substrate 200a exposed by the removal of the second modified layer 200d. That is, in step A after the second cycle, the second modified layer 200d formed in step B can be removed, and the first modified layer 200b can be formed on the surface of the substrate 200a. As a result, the total etching rate of the substrate 200a can be increased when the cycle of step A and step B is repeated non-simultaneously.

[0216] As the first gas, it is preferred to include one or more of the gases exemplified as the first gas, and as the second gas, it is preferred to include one or more of the gases exemplified as the second gas. It should be noted that the first gas and the second gas must be gases with different molecular structures. When the first gas and the second gas are such a combination, the above effect is particularly significant.

[0217] By performing the cycle of step A and step B non-simultaneously for a predetermined number of times, the etching process of the substrate 200a can be performed in a non-plasma atmosphere, and the controllability of the etching amount can be further improved. In addition, by performing the etching process in a non-plasma atmosphere, it is possible to prevent plasma from damaging the wafer 200 and the film formed on the surface of the wafer 200.

[0218] <Other aspects of the present invention>

[0219] The embodiments of the present invention have been specifically described above, but the present invention is not limited to the above embodiments, and various modifications can be made without departing from the gist of the present invention.

[0220] For example, the substrate 200a serving as the first film (serving as the etching object film) may also be at least any one of a silicon nitride film (SiN film), a silicon carbon nitride film (SiCN film), a nitrogen-rich silicon oxynitride film (SiON film), a nitrogen-rich silicon oxycarbon nitride film (SiOCN film), a silicon boron nitride film (SiBN film), a silicon boron carbon nitride film (SiBCN film), a boron nitride film (BN film), a titanium nitride film (TiN film), a tungsten nitride film (WN film), a tungsten film (W film), a molybdenum film (Mo film), a silicon film (Si film), a germanium film (Ge film), and a silicon germanium film (SiGe film).

[0221] It should be noted that the O-containing film such as the SiON film or SiOCN film as the first film is preferably an N-enriched film, that is, a film in which the N concentration in the film is higher than the O concentration in the film. That is, the SiON film or SiOCN film is preferably an N-enriched SiON film or an N-enriched SiOCN film. Even if the first film contains O in addition to N, if the N concentration is higher than the O concentration, the first film can be sufficiently etched by the method described above.

[0222] As described above, for the substrate 200a (as the first film), in addition to nitrogen-containing films such as SiN film, SiCN film, N-rich SiON film, N-rich SiOCN film, SiBN film, SiBCN film and other silicon nitride films (silicon nitrogen-containing films), BN film and other boron nitride films (boron nitrogen-containing films), TiN film, WN film and other metal nitride films (metal nitrogen-containing films), it can also be metal films (transition metal films, transition metal single substance films) such as W film and Mo film, and semiconductor films such as Si film, Ge film, and SiGe film.

[0223] Even when the base 200a (as the first film) is at least one of the films, the same effects as those in the above embodiment can be obtained.

[0224] In addition, for example, as shown in the following processing sequence, a pre-process (step C) of supplying a third gas to the wafer 200 may be performed before supplying the first gas to the wafer 200. Thus, for example, the formation of the first modified layer 200b on the surface of the base 200a exposed on the surface of the wafer 200 can be promoted.

[0225] (third gas → first gas → second gas)×n

[0226] The following describes the processing steps and processing conditions in step C. It should be noted that the processing steps and processing conditions other than step C may be the same as those described above.

[0227] [Step C]

[0228] In step C, the third gas is supplied to the wafer 200 in the processing chamber 201 , that is, to the wafer 200 having the base 200 a (first film) exposed on the surface.

[0229] Specifically, the valve 243c is opened to allow the third gas to flow into the gas supply pipe 232c. The third gas is flow-regulated by the MFC 241c, supplied into the processing chamber 201 through the nozzle 249c, flows on the surface of the wafer 200, and is exhausted from the exhaust port 231a. At this time, the third gas is supplied to the wafer 200. In addition, at this time, the valves 243d to 243f may be opened to supply inactive gas into the processing chamber 201 through the nozzles 249a to 249c, respectively.

[0230] By supplying the third gas to the wafer 200 under the conditions described below, the surface of the substrate 200a exposed on the surface of the wafer 200 can be pretreated. For example, the surface of the substrate 200a can be pretreated so that the surface of the substrate 200a functions as an adsorption site of the first gas.

[0231] After the surface of the substrate 200a is pre-treated, the valve 243c is closed to stop the supply of the third gas into the processing chamber 201. Then, the processing chamber 201 is evacuated to remove the gas remaining in the processing chamber 201 from the processing chamber 201. At this time, the valves 243d to 243f may be opened to supply an inert gas into the processing chamber 201 through the nozzles 249a to 249c. The inert gas supplied from the nozzles 249a to 249c acts as a purge gas, thereby purging (purging) the processing chamber 201. The purge with the inert gas may not be performed.

[0232] The processing conditions when the third gas is supplied in step C may be exemplified as follows:

[0233] Processing temperature: 30~300℃

[0234] Processing pressure: 5~1000Pa

[0235] Third gas supply flow rate: 10 to 2000 sccm

[0236] Third gas supply time: 5 to 1800 seconds

[0237] Inert gas supply flow rate (each gas supply pipe): 0 to 10,000 sccm.

[0238] The third gas is not particularly limited, and may be any gas capable of performing the above-mentioned pre-treatment, that is, any gas capable of forming adsorption sites for the first gas on the surface of the substrate 200 a .

[0239] As the third gas, for example, a gas containing O and H can be used. As the gas containing O and H, for example, H 2 O gas, H 2 O 2 Gas, etc. In addition, as the gas containing O and H, O 2 Gas+H 2 Gas such as O-containing gas and H-containing gas. When the above gas is used as the third gas, in step C, the surface of the substrate 200a is terminated by hydroxyl (OH). That is, in this case, OH termination is formed on the surface of the substrate 200a as an adsorption site. When the surface of the substrate 200a is used as an adsorption site to form OH termination, as the first gas, it is preferable to use a gas that reacts with OH termination, for example, the above-mentioned aminosilane gas can be used.

[0240] In addition, as the third gas, for example, a gas containing N and H can be used. As the gas containing N and H, for example, NH 3 Gas, N 2 H 4 Gas, N 2 H 2When the above gases are used as the third gas, in step C, the surface of the substrate 200a is terminated by NH groups. That is, in this case, NH termination is formed on the surface of the substrate 200a as an adsorption site. When NH termination is formed on the surface of the substrate 200a as an adsorption site, as the first gas, it is preferred to use a gas that reacts with NH termination, for example, the above-mentioned halogenated silane gas, alkylhalogenated silane gas, etc. can be used. In this case, as the halogenated silane gas and alkylhalogenated silane gas, it is preferred to use the above-mentioned chlorosilane gas and alkylchlorosilane gas.

[0241] In addition, as the third gas, for example, a gas containing N and H or a gas containing N plasma can be used. For example, as the third gas, NH 3 Gas, N 2 H 4 Gas, N 2 H 2 Gas, N 2 When a gas containing N and H is excited and used as a plasma as the third gas, a gas containing NH 3 * NH 2 * NH * In this case, in step C, the surface of the substrate 200a is terminated with NH groups, and NH termination is formed on the surface of the substrate 200a as an adsorption site. In addition, when N-containing gas is excited as a plasma and used as the third gas, N-containing gas is supplied to the surface of the substrate 200a. 2 * 、N * In this case, in step C, the surface of the substrate 200a is N-terminated, and the N-terminus is formed on the surface of the substrate 200a as an adsorption site. In the case where the NH-terminus is formed on the surface of the substrate 200a as an adsorption site, as the first gas, it is preferred to use a gas that reacts with the NH-terminus, for example, the above-mentioned halogenated silane gas, alkylhalogenated silane gas, etc. can be used. In this case, as the halogenated silane gas, alkylhalogenated silane gas, it is preferred to use the above-mentioned chlorosilane gas, alkylchlorosilane gas. In addition, in the case where the surface of the substrate 200a is N-terminated as an adsorption site, as the first gas, it is preferred to use a gas that reacts with the N-terminus, for example, the above-mentioned aminosilane gas, etc.

[0242] According to this embodiment, the same effects as those of the above embodiment can be obtained. In addition, according to this embodiment, the adsorption of the first gas to the surface of the substrate 200a can be promoted, thereby shortening the processing time in step A. In addition, in step A, the adsorption layer of the first gas can be formed more uniformly within the surface of the substrate 200a, and the density of the adsorption layer of the first gas formed on the surface of the substrate 200a can be increased, thereby generating etching species more uniformly within the surface of the substrate 200a in step B. Furthermore, conformal etching can be performed thereby.

[0243] It should be noted that this embodiment is particularly effective when a modification reaction based on adsorption occurs in step A.

[0244] In addition, for example, Fig. 9 As shown in (a), for a wafer 200 having a substrate 200e (as a second film) having a material different from that of the substrate 200a exposed on the surface in addition to the substrate 200a (as a first film), a cycle of non-simultaneously performing step A and step B may be performed a predetermined number of times. The substrate 200a (as a first film) includes, for example, a silicon-based nitrogen-containing film such as a silicon nitride film (SiN film). In addition, the substrate 200e (as a second film) includes, for example, a silicon-based oxygen-containing film such as a silicon oxide film (SiO film).

[0245] The difference between this method and the above method is that in this method, a wafer 200 with a substrate 200a and a substrate 200e exposed on the surface is used, and the etching process of this method can be performed in the same manner as the etching process in the above method. That is, the processing steps and processing conditions of the etching process of this method can be the same as the processing steps and processing conditions of the etching process in the above method.

[0246] By performing a cycle of non-simultaneously performing step A and step B for a predetermined number of times on the wafer 200 having the substrate 200a and the substrate 200e exposed on the surface, the Fig. 9 (b) and Fig. 9 As shown in (c), the substrate 200a can be selectively etched relative to the substrate 200e. That is, by performing a cycle of step A and step B non-simultaneously for a predetermined number of times on the wafer 200 having the substrate 200a and the substrate 200e exposed on the surface, it is possible to promote the etching of the substrate 200a while suppressing the etching of the substrate 200e. The reason for this is believed to be that in the etching process of the above-mentioned method, the above-mentioned various reactions occur on the surface of the substrate 200a, but the above-mentioned various reactions are difficult to occur on the surface of the substrate 200e. It should be noted that Fig. 9 (b) shows the state of the surface of the wafer 200 during the etching process. Fig. 9 (c) shows the state of the surface of the wafer 200 after the etching process is completed.

[0247] According to this method, the substrate 200a can be etched with a selectivity of 5:1 or more, further with a selectivity of 10:1 or more, and further with a selectivity of 20:1 or more, relative to the substrate 200e. In addition, according to this method, the substrate 200a can be etched with a selectivity of 30:1 or more, further with a selectivity of 40:1 or more, further with a selectivity of 50:1 or more, and further with a selectivity exceeding 50:1 relative to the substrate 200e. In addition, according to this method, depending on the conditions, the substrate 200a can be etched without substantially etching the substrate 200e. It should be noted that in this specification, "the substrate 200a is etched with a selectivity of 5:1 or more relative to the substrate 200e" means that when the etching amount of the substrate 200e is set to "1", the etching amount of the substrate 200a is "5" or more.

[0248] As described above, according to this method, the etching of the substrate 200a can be promoted while the etching of the substrate 200e can be suppressed, and the substrate 200a can be etched with high selectivity relative to the substrate 200e. That is, according to this method, it is possible to selectively etch a specific film, that is, to achieve selective etching. In addition, according to this method, it is also possible to improve the controllability of the etching amount in the selective etching.

[0249] It should be noted that, in the present embodiment, it is preferred that the substrate 200a includes a nitride film and the substrate 200e includes a film other than the nitride film (e.g., an oxide film). It is preferred that the substrate 200a includes a silicon nitride film and the substrate 200e includes a film other than the silicon nitride film (e.g., a silicon oxide film). In addition, it is preferred that the substrate 200a includes a nitrogen-containing film and the substrate 200e includes a film other than the nitrogen-containing film (e.g., an oxygen-containing film). In addition, it is preferred that the substrate 200a includes a silicon- and nitrogen-containing film and the substrate 200e includes a film other than the silicon- and nitrogen-containing film (e.g., a silicon- and oxygen-containing film). In the case where the substrate 200a and the substrate 200e are such a combination, the above effect is particularly significant. It should be noted that the substrate 200a may also include a film other than the nitride film (silicon nitride film, a nitrogen-containing film, a silicon- and nitrogen-containing film). In addition, the substrate 200e may also be a film other than the oxide film (silicon oxide film, an oxygen-containing film, a silicon- and oxygen-containing film).

[0250] For example, the substrate 200a (first film) may be at least any one of a SiN film, a SiCN film, a N-enriched SiON film, a N-enriched SiOCN film, a SiBN film, a SiBCN film, a BN film, a TiN film, a WN film, a W film, a Mo film, a Si film, a Ge film, and a SiGe film, as in the above-mentioned manner. It should be noted that, as in the above-mentioned manner, it is preferred that the O-containing film such as the SiON film and the SiOCN film as the first film is a N-enriched film, that is, a film in which the N concentration in the film is higher than the O concentration in the film. As described above, with respect to the substrate 200a (the first film), in addition to nitrogen-containing films such as SiN films, SiCN films, N-rich SiON films, N-rich SiOCN films, SiBN films, SiBCN films and other silicon-based nitride films (silicon-based nitrogen-containing films), BN films and other boron-based nitride films (boron-based nitrogen-containing films), TiN films, WN films and other metal-based nitride films (metal-based nitrogen-containing films), it can also be metal films (transition metal films, transition metal single substance films) such as W films and Mo films, and semiconductor films such as Si films, Ge films, and SiGe films.

[0251] In addition, the substrate 200e (the second film) may be at least any one of a silicon oxide film (SiO film), a silicon oxycarbide film (SiOC film), an oxygen-rich silicon oxynitride film (SiON film), an oxygen-rich silicon oxycarbonitride film (SiOCN film), a titanium oxide film (TiO film), a hafnium oxide film (HfO film), a zirconium oxide film (ZrO film), an aluminum oxide film (AlO film), and an aluminum film (Al film).

[0252] It should be noted that the O-containing film such as the SiON film or SiOCN film as the second film is preferably an O-enriched film, that is, a film in which the O concentration in the film is higher than the N concentration in the film. That is, the SiON film or SiOCN film is preferably an O-enriched SiON film or an O-enriched SiOCN film. Even if the second film contains N in addition to O, if the O concentration is higher than the N concentration, etching of the second film by the method in the above manner can be suppressed.

[0253] As described above, with respect to the substrate 200e (the second film), in addition to oxygen-containing films such as silicon-based oxide films (silicon-based oxygen-containing films) such as SiO films, SiOC films, O-rich SiON films, and O-rich SiOCN films, and metal-based oxide films (metal-based oxygen-containing films) such as TiO films, HfO films, ZrO films, and AlO films, it may also be a metal film (non-transition metal film, non-transition metal single substance film) such as Al film.

[0254] In addition, for example, in addition to the first film (base 200a), multiple films such as a second film (base 200e) and a third film may be exposed on the surface of the wafer 200. The film exposed on the surface of the wafer 200 (specifically, the first film, the second film, the third film, etc.) may be any of the films exemplified as the first film and the films exemplified as the second film.

[0255] For example, a SiN film, a SiO film, and a Si film may be exposed on the surface of the wafer 200 as the first film, the second film, and the third film, respectively. In this case, the SiN film and the Si film can be selectively etched relative to the SiO film. In addition, for example, a SiCN film, a SiOC film, and an AlO film may be exposed on the surface of the wafer 200 as the first film, the second film, and the third film, respectively. In this case, the SiCN film can be selectively etched relative to the SiOC film and the AlO film. In addition, for example, an N-rich SiOCN film, an O-rich SiOCN film, an N-rich SiON film, and an O-rich SiON film may be exposed on the surface of the wafer 200 as the first film, the second film, the third film, and the fourth film, respectively. In this case, the N-rich SiOCN film and the N-rich SiON film can be selectively etched relative to the O-rich SiOCN film and the O-rich SiON film. In these cases, the same effect as the above-mentioned method can be obtained.

[0256] It is preferred that the recipe used in each process is prepared separately according to the process content, and is stored in advance in the storage device 121c via the electrical communication line and the external storage device 123. In addition, when starting each process, it is preferred that the CPU 121a appropriately selects an appropriate recipe from the multiple recipes stored in the storage device 121c according to the process content. In this way, a variety of etching processes can be achieved with good reproducibility using one substrate processing device. In addition, each process can be started quickly while reducing the burden on the operator and avoiding operational errors.

[0257] The above-mentioned process is not limited to the case of newly creating, and can also be prepared by, for example, changing an existing process installed in a substrate processing device. In the case of changing a process, the changed process can also be installed in the substrate processing device via an electrical communication line or a recording medium recording the process. In addition, the input / output device 122 of the existing substrate processing device can be operated to directly change the existing process installed in the substrate processing device.

[0258] In the above-mentioned method, an example of etching processing using a batch-type substrate processing device that processes a plurality of substrates at a time is described. The present invention is not limited to the above-mentioned method, and for example, it can also be preferably applied to a case where etching processing is performed using a single-wafer type substrate processing device that processes one or several substrates at a time. In addition, in the above-mentioned method, an example of etching processing using a substrate processing device having a hot wall type processing furnace is described. The present invention is not limited to the above-mentioned method, and it can also be preferably applied to a case where etching processing is performed using a substrate processing device having a cold wall type processing furnace.

[0259] When the above substrate processing apparatus is used, each process can be performed in the same process steps and process conditions as those in the above-mentioned manner, and the same effects as those in the above-mentioned manner can be obtained.

[0260] The above-mentioned methods can be used in combination as appropriate. The processing steps and processing conditions in this case may be the same as those in the above-mentioned methods, for example.

[0261] Example

[0262] (Reference Example 1)

[0263] The substrate processing apparatus is used to etch the SiN film and the SiO film exposed on the surface of the wafer using the first gas alone, and the etching amounts thereof are measured. As the first gas, one of the fluorine-based gases exemplified as the first gas in the above-mentioned method is used. As for the processing conditions, except that the processing temperature is set to 100° C., 250° C., 350° C. or 400° C., the processing conditions are set to the prescribed conditions within the range of the processing conditions in the above-mentioned step A.

[0264] Figure 6 2 shows the measurement results of the etching amount in Reference Example 1. Figure 6 The horizontal axis represents the processing temperature (°C). Figure 6 The vertical axis represents the etching amount of SiN film and SiO film. In addition, Figure 6 In the figure, ■ marks represent the measurement results of the etching amount of the SiO film, and ● marks represent the measurement results of the etching amount of the SiN film.

[0265] from Figure 6 It can be seen that when the first gas is used alone, no etching occurs on either the SiN film or the SiO film when the treatment temperature is 100 to 250° C. On the other hand, it can be seen that when the treatment temperature exceeds 250° C., even when the first gas is used alone, the SiN film is etched, while the SiO film is slightly etched.

[0266] (Reference Example 2)

[0267] Using the above substrate processing apparatus, the second gas alone is used to etch the SiN film and the SiO film exposed on the surface of the wafer, and the etching amount is measured. As the second gas, a gas having a molecular structure different from that of the first gas in Reference Example 1 is used, and it is one of the fluorine-based gases exemplified as the second gas in the above method. As for the processing conditions, except that the processing temperature is set to 35°C or 100°C, it is set to the specified conditions within the range of the processing conditions in the above step B.

[0268] Figure 7 . The measurement results of the etching amount of Reference Example 2 are shown in FIG. Figure 7 The horizontal axis represents the processing temperature (°C). Figure 7 The vertical axis represents the etching amount of SiN film and SiO film. In addition, Figure 7 In FIG. 1 , ■ marks show the measurement results of the etching amount of the SiO film, and ● marks show the measurement results of the etching amount of the SiN film.

[0269] from Figure 7 It can be seen that in the case of the treatment performed by the second gas alone, when the treatment temperature is 35 to 100°C, neither the SiN film nor the SiO film is etched. It should be noted that in the case of the treatment performed by the second gas alone, when the treatment temperature is 100 to 250°C, it is confirmed that there is a tendency that neither the SiN film nor the SiO film is etched. In addition, the following tendency is confirmed: if the treatment temperature exceeds 250°C, even if the treatment is performed by the second gas alone, either the SiN film or the SiO film is slightly etched, and if the treatment temperature reaches 400°C or more, even if the treatment is performed by the second gas alone, either the SiN film or the SiO film is etched.

[0270] (Example)

[0271] Using the above substrate processing apparatus, by Figure 4 The processing sequence shown performs etching processing on the SiN film and the SiO film exposed on the surface of the wafer, and measures the etching amount. As the first gas, the same gas as the first gas in Reference Example 1 is used, and as the second gas, the same gas as the second gas in Reference Example 2 is used. As for the processing conditions, except that the processing temperature is set to 100° C., the processing conditions are set to the prescribed conditions within the range of the processing conditions in the above steps A and B.

[0272] Figure 8 The results of measuring the etching amount in the examples are shown in FIG. For comparison, the etching amount when the processing temperature in Reference Examples 1 and 2 is set to 100° C. is also shown in FIG. Figure 8 middle. Figure 8 The vertical axis represents the etching amount of SiN film and SiO film respectively. exist Figure 8 In the figure, ■ marks indicate the measurement results of SiO films, and ● marks indicate the measurement results of SiN films.

[0273] like Figure 8 As shown in FIG. 1 , it can be seen that when the processing temperature is 100°C, no matter whether the first gas is used alone for processing (reference example 1) or the second gas is used alone for processing (reference example 2), no etching is performed on the SiN film or the SiO film. On the other hand, it can be seen that in the embodiment, when the processing temperature is 100°C, by following the Figure 4The etching process is performed at the processing sequence shown in FIG. 1 , so that although the SiO film is hardly etched, the SiN film is nearly etched. It should be noted that, Figure 8 In the illustrated embodiment, the SiN film is etched with a selectivity of 35:1 to 45:1 with respect to the SiO film.

[0274] The above-mentioned difference in etching amount, that is, the difference between the etching amount of the SiO film in Reference Example 1, Reference Example 2 and the embodiment and the etching amount of the SiN film in the embodiment, has the same tendency at least in the range of processing temperature 25 to 250°C. In addition, such a difference in etching amount also has a similar tendency in the range of 250 to 400°C. Therefore, in accordance with Figure 4 When the etching process is performed in the process sequence shown, it is preferably performed at a process temperature in the range of 25 to 400°C, more preferably in the range of 25 to 250°C.

Claims

1. A processing method comprising the step of etching a first substrate by alternately performing the following steps: (a) supplying a first gas to a substrate to form a first layer on at least a portion of a surface of a first base on a surface of the substrate; and (b) supplying a second gas having a molecular structure different from that of the first gas to the substrate, thereby generating etching species by at least one of causing the second gas to react with the first layer and activating the first layer by the second gas, In (b), a second layer removable by the first gas is formed on at least a portion of the surface of the first substrate after the etching species has contacted the first substrate.

2. The processing method according to claim 1, in, In (a), at least a portion of the molecules of the first gas are physically adsorbed or chemically adsorbed on at least a portion of the surface of the first base, thereby forming the first layer.

3. The processing method according to claim 1, in, In (a), the first layer is formed by generating a compound through a chemical reaction between at least a portion of the molecules of the first gas and at least a portion of the atoms or molecules on the surface of the first base.

4. The processing method according to claim 1, in, In (b), the second gas is supplied to the substrate under the condition that the reaction of the second gas with the first layer occurs predominantly compared with the reaction of the second gas with the first underlayer.

5. The processing method according to claim 1, in, In (b), the second gas is supplied to the substrate under the condition that a reaction between the second gas and the first layer proceeds but a reaction between the second gas and the first underlayer does not proceed.

6. The processing method according to claim 1, in, In (b), the second gas is supplied to the substrate under the condition that activation of the first layer by the second gas is dominant over activation of the first underlayer by the second gas.

7. The processing method according to claim 1, in, In (b), the second gas is supplied to the substrate under the condition that activation of the first layer by the second gas proceeds but activation of the first underlayer by the second gas does not proceed.

8. The processing method according to claim 1, in, In (b), the second gas is supplied to the substrate under the condition that the reaction of the etching species with at least a portion of the first underlayer occurs predominantly compared to the reaction of the second gas with the first underlayer.

9. The processing method according to claim 1, in, In (b), the second gas is supplied to the substrate under the condition that a reaction between the etching species and at least a portion of the first base proceeds but a reaction between the second gas and the first base does not proceed.

10. The processing method according to claim 1, in, In (b), at least a portion of the surface of the first base is removed by the etching species, and the second layer is formed on at least a portion of the surface of the first base from which at least a portion of the surface is removed.

11. The processing method according to claim 10, in, In the etching process, (a) and (b) are performed alternately multiple times, and the first gas is supplied to the substrate in (a) after the second time, so that the first gas reacts with the second layer to remove the second layer, and the first layer is formed on at least a portion of the surface of the first substrate from which the second layer is removed.

12. The processing method according to claim 1, in, The first substrate includes a nitrogen-containing film, a transition metal film or a semiconductor film.

13. The treatment method according to any one of claims 1 to 12, in, A second base is also provided on the surface of the substrate, In the etching step, the first base is selectively etched with respect to the second base.

14. The processing method according to claim 13, in, The first substrate includes a nitrogen-containing film, a transition metal film, or a semiconductor film, and the second substrate includes an oxygen-containing film or a non-transition metal film.

15. The processing method according to claim 14, in, The nitrogen-containing film includes a silicon-based nitrogen-containing film, a boron-based nitrogen-containing film, or a metal-based nitrogen-containing film.

16. The processing method according to claim 14, in, The oxygen-containing film includes a silicon-based oxygen-containing film or a metal-based oxygen-containing film.

17. The processing method according to claim 13, in, In the etching step, the first base is etched with a selectivity of 5:1 or more with respect to the second base.

18. The treatment method according to any one of claims 1 to 12, in, The first gas includes one or more of a silicon-containing gas, a metal-containing gas, an oxygen-containing gas, a nitrogen- and hydrogen-containing gas, a boron-containing gas, a phosphorus-containing gas, and a halogen-containing gas. The second gas includes at least one of a halogen-containing gas and an acetylacetone-based gas.

19. The treatment method according to any one of claims 1 to 12, in, The etching is performed in a non-plasma atmosphere.

20. The treatment method according to any one of claims 1 to 12, in, The etching is performed under the condition that the etching reaction of the first base is difficult to proceed when at least one of the first gas and the second gas exists alone.

21. A method for manufacturing a semiconductor device, comprising the step of etching a first substrate by alternately performing the following steps: (a) supplying a first gas to a substrate to form a first layer on at least a portion of a surface of a first base on a surface of the substrate; and (b) supplying a second gas having a molecular structure different from that of the first gas to the substrate, thereby generating etching species by at least one of causing the second gas to react with the first layer and activating the first layer by the second gas, In (b), a second layer removable by the first gas is formed on at least a portion of the surface of the first substrate after the etching species has contacted the first substrate.

22. A processing device comprising: a first gas supply system for supplying a first gas to the substrate; a second gas supply system for supplying a second gas having a molecular structure different from that of the first gas to the substrate; and The control unit is configured to control the operation of the processing device so as to perform etching processing on the first substrate by alternately performing the following processing: (a) supplying the first gas to a substrate to form a first layer on at least a portion of a surface of a first base on a surface of the substrate; and (b) supplying the second gas to the substrate to generate etching species by at least one of causing the second gas to react with the first layer and activating the first layer by the second gas, In (b), a second layer removable by the first gas is formed on at least a portion of the surface of the first substrate after the etching species has contacted the first substrate.

23. A program product which, through a computer, causes a processing device to execute the following steps: (a) supplying a first gas to a substrate to form a first layer on at least a portion of a surface of a first base on a surface of the substrate; (b) supplying a second gas having a molecular structure different from that of the first gas to the substrate, thereby generating etching species by at least one of reacting the second gas with the first layer and activating the first layer with the second gas; and In (b), a step of forming a second layer removable by the first gas on at least a portion of the surface of the first substrate after the etching species has contacted the first substrate.

Images