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

Abstract

To precisely form a film in a recess provided on the surface of a substrate.SOLUTION: (a) supplying a film forming agent to a substrate having a recess on a surface thereof, the recess having a bottom surface constituted by a first base and a side surface constituted by a second base; The method comprises a step of forming a first film, which is thicker than a first film formed on the second base, on the first base, and a step of (b) supplying an etching agent to the substrate and removing the first film formed on the second base while leaving at least a part of the first film formed on the first base.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] BACKGROUND ART As one step in the manufacturing process of a semiconductor device, a process of forming a film on the surface of a substrate is sometimes performed (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2021-136349 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a technique that enables a film to be precisely formed within a recess provided on the surface of a substrate. [Means for solving the problem]

[0005] According to one aspect of the present disclosure, (a) supplying a film-forming agent to a substrate having a recess on its surface, the recess having a bottom surface formed by a first underlayer and a side surface formed by a second underlayer, and forming the first film on the first underlayer to a thickness greater than that of a first film formed on the second underlayer; (b) supplying an etching agent to the substrate to remove the first film formed on the second underlayer while leaving at least a portion of the first film formed on the first underlayer; The present invention provides a technique having the following. [Effects of the Invention]

[0006] According to the present disclosure, it is possible to precisely form a film within a recess provided on the surface of a substrate. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic configuration diagram of a vertical processing furnace of a substrate processing apparatus suitably used in one embodiment of the present disclosure, showing a processing furnace 202 portion in vertical cross section. [Figure 2] FIG. 2 is a schematic configuration diagram of a vertical processing furnace of a substrate processing apparatus suitably used in one embodiment of the present disclosure, and is a cross-sectional view of the processing furnace 202 taken along line AA in FIG. [Figure 3] FIG. 3 is a schematic configuration diagram of a controller 121 of a substrate processing apparatus suitably used in one embodiment of the present disclosure, and is a block diagram showing a control system of the controller 121. [Figure 4] FIG. 4(a) is a partial cross-sectional enlarged view showing a surface portion of a substrate according to an embodiment of the present disclosure having a recess on its surface. FIG. 4(b) is a partial cross-sectional enlarged view showing a surface portion of a substrate according to an embodiment of the present disclosure after performing step A1 from the state of FIG. 4(a). FIG. 4(c) is a partial cross-sectional enlarged view showing a surface portion of a substrate according to an embodiment of the present disclosure after performing a predetermined number of cycles including steps A2 and A3 from the state of FIG. 4(b). FIG. 4(d) is a partial cross-sectional enlarged view showing a surface portion of a substrate according to an embodiment of the present disclosure after performing a predetermined number of cycles including steps B1 and B2 from the state of FIG. 4(c). FIG. 4(e) is a partial cross-sectional enlarged view showing a surface portion of a substrate according to an embodiment of the present disclosure after performing step C1 from the state of FIG. 4(d). FIG. 4(f) is a partial cross-sectional enlarged view showing a surface portion of a substrate according to an embodiment of the present disclosure after performing a predetermined number of cycles including steps C2 and C3 from the state of FIG. 4(e). DETAILED DESCRIPTION OF THE INVENTION

[0008] <One aspect of the present disclosure> Hereinafter, one embodiment of the present disclosure will be described mainly with reference to Figures 1 to 3 and 4(a) to 4(f). Note that the drawings used in the following description are all schematic, and the dimensional relationships between elements, the ratios of elements, etc. shown in the drawings do not necessarily match those in reality. Furthermore, the dimensional relationships between elements, the ratios of elements, etc. do not necessarily match between multiple drawings.

[0009] (1) Configuration of the substrate processing equipment As shown in Fig. 1, a processing furnace 202 of the substrate processing apparatus includes a reaction tube 203. A manifold 209 is disposed below the reaction tube 203. A processing vessel is mainly formed by the reaction tube 203 and the manifold 209. A processing chamber 201 is formed inside the processing vessel. The processing chamber 201 is configured to be able to accommodate wafers 200 as substrates.

[0010] A heater 207 is provided outside the reaction tube 203 to heat the wafers 200 in the processing chamber 201. The heater 207 also functions as an activation mechanism that thermally activates the gas in the processing chamber 201. A temperature sensor 263 is provided inside the reaction tube 203.

[0011] Nozzles 249a to 249c are provided in the processing chamber 201. As shown in Fig. 2, the nozzles 249a to 249c are provided along the inner wall of the reaction tube 203, rising upward in the arrangement direction of the wafers 200. A plurality of gas supply holes 250a to 250c are provided on the side surfaces of the nozzles 249a to 249c from the bottom to the top of the reaction tube 203.

[0012] Gas supply pipes 232a to 232c are connected to the nozzles 249a to 249c. Mass flow controllers (MFCs) 241a to 241c and valves 243a to 243c are provided on the gas supply pipes 232a to 232c. Gas supply pipes 232d and 232f are connected to the gas supply pipe 232a downstream of the valve 243a. Gas supply pipes 232e and 232g are connected to the gas supply pipe 232b downstream of the valve 243b. Gas supply pipe 232h is connected to the gas supply pipe 232c downstream of the valve 243c. MFCs 241d to 241h and valves 241d to 241h are provided on the gas supply pipes 232d to 232h.

[0013] From the gas supply pipe 232a, modifying agents (first and second modifying agents) are supplied into the processing chamber 201 via the MFC 241a, the valve 243a, and the nozzle 249a.

[0014] Film forming agents (first and second film forming agents) are supplied from the gas supply pipe 232b into the processing chamber 201 via the MFC 241b, the valve 243b, and the nozzle 249b.

[0015] Reactants (first to fifth reactants) are supplied from the gas supply pipe 232c into the processing chamber 201 via the MFC 241c, the valve 243c, and the nozzle 249c.

[0016] An etching agent is supplied from the gas supply pipe 232d into the processing chamber 201 via the MFC 241d, the valve 243d, the gas supply pipe 232a, and the nozzle 249a.

[0017] A catalyst is supplied from the gas supply pipe 232e into the processing chamber 201 via the MFC 241e, the valve 243e, the gas supply pipe 232b, and the nozzle 249b.

[0018] Inert gas is supplied from the gas supply pipes 232f to 232h through the MFCs 241f to 241h, the valves 243f to 243h, the gas supply pipes 232a to 232c, and the nozzles 249a to 249c into the processing chamber 201. The inert gas acts as a purge gas, a carrier gas, a dilution gas, or the like.

[0019] A modifying agent supply system is mainly constituted by the gas supply pipe 232a, MFC 241a, and valve 243a. A film-forming agent supply system is mainly constituted by the gas supply pipe 232b, MFC 241b, and valve 243b. A reactant supply system is mainly constituted by the gas supply pipe 232c, MFC 241c, and valve 243c. An etching agent supply system is mainly constituted by the gas supply pipe 232d, MFC 241d, and valve 243d. A catalyst supply system is mainly constituted by the gas supply pipe 232e, MFC 241e, and valve 243e. An inert gas supply system is mainly constituted by the gas supply pipes 232f-232h, MFCs 241f-241h, and valves 243f-243h. Any or all of the various supply systems described above may be configured as an integrated supply system 248 in which the valves 243a to 243h, the MFCs 241a to 241h, and the like are integrated.

[0020] An exhaust port 231a is provided below the reaction tube 203. A vacuum pump 246 is connected to the exhaust pipe 231 via a pressure sensor 245 and an APC (Auto Pressure Controller) valve 244. An exhaust system is mainly configured by the exhaust pipe 231, the APC valve 244, and the pressure sensor 245. The vacuum pump 246 may be included in the exhaust system.

[0021] A seal cap 219 is provided below the manifold 209. A rotation mechanism 267 that rotates a boat 217 (described later) is installed in the seal cap 219. The seal cap 219 is raised and lowered by a boat elevator 115. The boat elevator 115 functions as a transfer mechanism that transfers wafers 200 into and out of the processing chamber 201.

[0022] A shutter 219s capable of airtightly closing the lower end opening of the manifold 209 is provided below the manifold 209. The opening and closing operation of the shutter 219s is controlled by a shutter opening and closing mechanism 115s.

[0023] The boat 217 as a substrate support is configured to support a plurality of wafers 200, for example, 25 to 200 wafers 200, in multiple stages, in a horizontal position, with their centers aligned and aligned vertically. At the bottom of the boat 217, heat insulating plates 218 are supported in multiple stages.

[0024] 3, the controller 121, which is a control unit, is configured as a computer including a CPU 121a, a RAM 121b, a storage device 121c, and an I / O port 121d. The RAM 121b, the storage device 121c, and the I / O port 121d are configured to be able to exchange data with the CPU 121a via an internal bus 121e. An input / output device 122 configured as a touch panel or the like is connected to the controller 121. An external storage device 123 can be connected to the controller 121.

[0025] The storage device 121c is composed of a flash memory, an HDD, an SSD, etc. Control programs for controlling the operation of the processing device, process recipes describing procedures and conditions for substrate processing (described later), etc. are readably recorded and stored in the storage device 121c. A process recipe is a combination of procedures for substrate processing (described later) that are executed by the controller 121 in the processing device to obtain a predetermined result, and functions as a program. Hereinafter, process recipes, control programs, etc. are collectively referred to simply as programs (program products). A process recipe is also simply referred to as a recipe. In this specification, the term "program" may include only a recipe, only a control program, or both.

[0026] The I / O port 121d is connected to the MFCs 241a to 241h, the valves 243a to 243h, the pressure sensor 245, the APC valve 244, the vacuum pump 246, the temperature sensor 263, the heater 207, the rotation mechanism 267, the boat elevator 115, the shutter opening / closing mechanism 115s, etc. The I / O port 121d may further be connected to an etching unit.

[0027] The CPU 121a is configured to read and execute a control program from the storage device 121c, and to read a recipe from the storage device 121c in response to an input of an operation command from the input / output device 122. The CPU 121a is configured to control, in accordance with the contents of the read recipe, the flow rate adjustment operation of various substances by the MFCs 241a-241h, the opening and closing operation of the valves 243a-243h, the opening and closing operation of the APC valve 244 and the pressure adjustment operation by the APC valve 244 based on the pressure sensor 245, the start and stop of the vacuum pump 246, the temperature adjustment operation of the heater 207 based on the temperature sensor 263, the rotation and rotation speed adjustment operation of the boat 217 by the rotation mechanism 267, the lifting and lowering operation of the boat 217 by the boat elevator 115, and the opening and closing operation of the shutter 219s by the shutter opening and closing mechanism 115s. The CPU 121a may also be configured to control an etching unit.

[0028] The controller 121 can be configured by installing the above-mentioned program recorded and stored in the external storage device 123 into a computer. The external storage device 123 includes a magnetic disk such as an HDD, an optical disk such as a CD, and a semiconductor memory such as a USB memory or an SSD. The storage device 121c and the external storage device 123 are configured as computer-readable recording media. Hereinafter, these will be collectively referred to simply as recording media. When the term recording media is used in this specification, it may include only the storage device 121c alone, only the external storage device 123 alone, or both. The program may be provided to the computer using a communication means such as the Internet.

[0029] (2) Substrate processing process An example of a processing sequence for forming a film in a recess provided on the surface of a wafer 200 as a substrate, as one step in a manufacturing process (manufacturing method) of a semiconductor device using the above-mentioned substrate processing apparatus, will be described mainly with reference to Figures 4(a) to 4(f). The series of processing sequences shown below are performed by the above-mentioned substrate processing apparatus. At this time, the operation of each part constituting the substrate processing apparatus is controlled by a controller 121.

[0030] In the processing sequence of this embodiment, (a) Step A of supplying a first film-forming agent to a wafer 200 having a recess on its surface, the recess having a bottom surface formed by a first underlayer and a side surface formed by a second underlayer, and selectively forming a first film on the first underlayer to a thickness greater than that of a first film formed on the second underlayer; (b) Step B of supplying an etching agent to the wafer 200 and removing the first film formed on the second underlayer while leaving at least a portion of the first film formed on the first underlayer remaining. Fig. 4(a) shows the state (initial state) inside a recess in the surface of the wafer 200 to be processed.

[0031] In the following example, in step A, before supplying the first film forming agent to the wafer 200, (a1) A case will be described in which step A1 is performed in which a first modifying agent is supplied to the wafer 200 to modify the surface of the second underlayer into a surface having a first termination that suppresses adsorption of at least a portion of the first film-forming agent selectively relative to the surface of the first underlayer. Figure 4(b) shows the state of the recess after step A1 has been performed, from the state shown in Figure 4(a).

[0032] In the following example, after step A1 is performed in step A, (a2) Step A2 of supplying a first film forming agent to the wafer 200; (a3) Step A3 of supplying a first reactant to the wafer 200; A predetermined number of cycles (nA times, n A 4(c) shows the state of the inside of the recess after a cycle including steps A2 and A3 has been performed a predetermined number of times from the state shown in FIG. 4(b).

[0033] Also, in the following example, in step B, (b1) Step B1 of supplying a second reactant to the wafer 200 to react with the first film; (b2) Step B2 of supplying an etching agent to the wafer 200, the etching agent being a substance different from the second reactant; A predetermined number of cycles (n B times, n B 4(d) shows the state of the inside of the recess after a cycle including steps B1 and B2 has been performed a predetermined number of times from the state shown in FIG. 4(c).

[0034] Also, in the following example, after step B, (c) A case where step C is performed in which a second film forming agent is supplied to the wafer 200 to form a second film having a different composition from the first film on the first film will be described.

[0035] In the following example, in step C, before the second film forming agent is supplied to the wafer 200, (c1) A case where step C1 is performed in which a second modifying agent is supplied to the wafer 200 and the surface of the second base is modified to a surface having a second termination that suppresses adsorption of at least a part of the second film-forming agent selectively relative to the surface of the first base is described. Figure 4(e) shows the state of the recess after step C1, which is different from the state shown in Figure 4(d).

[0036] In the following example, after performing step C1 in step C, (c2) Step C2 of supplying a second film forming agent to the wafer 200; (c3) Step C3 of supplying a third reactant to the wafer 200; A predetermined number of cycles (n ctimes, n c 4(f) shows the state of the inside of the recess after a cycle including steps C2 and C3 has been performed a predetermined number of times from the state shown in FIG. 4(e).

[0037] In the present disclosure, the above processing sequence may also be indicated as follows. Step A: First modifier → (first film-forming agent → first reactant) × n A Step B: (second reactant → etchant) × n B Step C: second modifier → (second film-forming agent → third reactant) × n c

[0038] The term "wafer" used in this specification may refer to the wafer itself or to a laminate of the wafer and a predetermined layer or film formed on its surface. The term "surface of a wafer" used in this specification may refer to the surface of the wafer itself or to the surface of a predetermined layer or the like formed on the wafer. When described in this specification, "forming a predetermined layer on the surface of a wafer" may mean forming a predetermined layer directly on the surface of the wafer itself or forming a predetermined layer on a layer or the like formed on the wafer. When used in this specification, the term "substrate" is synonymous with the term "wafer".

[0039] The terms "agent" and "substance" used in this specification include at least one of a gaseous substance and a liquid substance. Liquid substances include mist-like substances. That is, each of the modifier, film-forming agent, reactant, etching agent, and catalyst described below may contain a gaseous substance, a liquid substance such as a mist-like substance, or both.

[0040] The processing sequence in this embodiment will be specifically described below.

[0041] (Wafer charge and boat load) When a plurality of wafers 200 are loaded into the boat 217 (wafer charge), the shutter 219s is moved by the shutter opening / closing mechanism 115s to open the lower end opening of the manifold 209 (shutter open). Thereafter, as shown in Fig. 1, the boat 217 supporting the plurality of wafers 200 is lifted by the boat elevator 115 and carried into the processing chamber 201 (boat load). In this state, the seal cap 219 seals the lower end of the manifold 209 via the O-ring 220b.

[0042] The wafer 200 to be processed has a three-dimensional structure, i.e., a recess, such as a trench or hole, on its surface. As shown in FIG. 4(a), the recess has a bottom surface formed by a first underlayer and side surfaces formed by a second underlayer. Such a structure can be formed by a known method, for example, by forming a layered structure of a second underlayer / sacrificial film / second underlayer on the surface of the wafer 200, patterning this layered structure, forming a first underlayer on the side surfaces, and then using an etching solution with a predetermined etching selectivity to selectively etch only the sacrificial film while suppressing etching of the first underlayer and second underlayer.

[0043] The first underlayer may be composed of a material containing non-metallic elements, particularly metalloid elements (Si, B, Ge, As, Sb, Te, etc.) and nitrogen (N), such as silicon nitride (SiN), silicon carbonitride (SiCN), silicon boronitride (SiBN), or silicon boron carbonitride (SiBCN).

[0044] The second underlayer may be made of a material containing a nonmetallic element, particularly a semimetallic element, and oxygen (O), such as silicon oxide (SiO), silicon oxynitride (SiON), silicon oxycarbide (SiOC), silicon oxycarbonitride (SiOCN), silicon boron oxynitride (SiBON), or silicon boron carbonate nitride (SiBCON).

[0045] The second underlayer may be made of a material containing a metal element (Al, Ti, Zr, Hf, Ta, Mo, etc.), a non-metal element (particularly a metalloid element), and O, such as aluminum silicon oxide (AlSiO), titanium silicon oxide (TiSiO), zirconium silicon oxide (ZrSiO), hafnium silicon oxide (HfSiO), tantalum silicon oxide (TaSiO), or molybdenum silicon oxide (MoSiO).

[0046] The second underlayer may be made of a material containing a metal element and O, such as aluminum oxide (AlO), titanium oxide (TiO), zirconium oxide (ZrO), hafnium oxide (HfO), tantalum oxide (TaO), molybdenum oxide (MoO), zirconium aluminum oxide (ZrAlO), or hafnium aluminum oxide (HfAlO).

[0047] (pressure and temperature regulation) After the boat loading is completed, the processing chamber 201, i.e., the space in which the wafers 200 are present, is evacuated (reduced pressure exhausted) by the vacuum pump 246 so that the interior of the processing chamber 201 is at a desired pressure (vacuum level). At this time, the pressure inside the processing chamber 201 is measured by the pressure sensor 245, and the APC valve 244 is feedback-controlled based on the measured pressure information. Furthermore, the wafers 200 inside the processing chamber 201 are heated by the heater 207 so that the processing temperature is at a desired processing temperature. At this time, the power supply to the heater 207 is feedback-controlled based on temperature information detected by the temperature sensor 263 so that the processing chamber 201 has a desired temperature distribution. Furthermore, the rotation mechanism 267 starts to rotate the wafers 200. The evacuation inside the processing chamber 201 and the heating and rotation of the wafers 200 are all continued at least until the processing of the wafers 200 is completed.

[0048] (Step A) Next, the wafer 200 prepared in the processing chamber 201 is subjected to the following steps A1 to A3.

[0049] [Step A1] In this step, the valve 243a is opened to allow a modifying agent (first modifying agent) to flow into the gas supply pipe 232a. The first modifying agent has its flow rate adjusted by the MFC 241a, is supplied into the processing chamber 201 through the nozzle 249a, and is exhausted from the exhaust port 231a. At this time, the first modifying agent is supplied onto the wafer 200 from the side of the wafer 200, and the wafer 200 is exposed to the first modifying agent (first modifying agent supply and exposure). At this time, the valves 243f to 243h may be opened to supply an inert gas into the processing chamber 201 through each of the nozzles 249a to 249c.

[0050] By performing this step under the processing conditions described below, it is possible to selectively adsorb at least a portion of the molecular structure of the molecules constituting the first modifier onto the surface of the second underlayer relative to the surface of the first underlayer, thereby forming a predetermined adsorption layer (first inhibitor layer) on the surface of the second underlayer, as shown in FIG. 4(b). By using a substance described below as the first modifier and forming a first inhibitor layer on the surface of the second underlayer, the surface of the second underlayer is modified to a surface terminated with a hydrocarbon group such as an alkyl group, hydrogen (H), or fluorine (F) selectively relative to the surface of the first underlayer. These terminations (hydrocarbon group termination, H termination, F termination) function as inhibitors that suppress adsorption of the first film-forming agent onto the surface of the second underlayer in step A2 described below. In other words, by performing this step, the surface of the second underlayer is modified to a surface formed with first terminations that selectively suppress adsorption of at least a portion of the first film-forming agent relative to the surface of the first underlayer.

[0051] In this disclosure, the phrase "the surface of the second base is selectively modified relative to the surface of the first base" does not mean "only the surface of the second base is modified," but rather means "of the surfaces of the first and second bases, the surface of the second base is preferentially modified." In other words, the term "selectively" indicates the relative degree of modification of the surface of the second base with respect to the degree of modification of the surface of the first base, and does not completely exclude modification of the surface of the first base. The term "selectively" is used in substantially the same sense in each of the following steps.

[0052] After the surface of the second base is selectively modified, the valve 243a is closed to stop the supply of the first modifying agent to the wafer 200. Then, the processing chamber 201 is evacuated to remove gaseous substances remaining in the processing chamber 201. Furthermore, the valves 243f to 243h are opened to supply an inert gas into the processing chamber 201, thereby purging the processing chamber 201 (purging).

[0053] The processing conditions for supplying the first modifier in step A1 are as follows: Treatment temperature: room temperature (25°C) to 500°C, preferably room temperature to 250°C Treatment pressure: 1 to 2000 Pa, preferably 1 to 1000 Pa Processing time: 1 second to 120 minutes, preferably 30 seconds to 60 minutes First modifier supply flow rate: 0.001 to 3 slm, preferably 0.001 to 0.5 slm Inert gas supply flow rate (per gas supply pipe): 0 to 20 slm is exemplified.

[0054] In this specification, when a numerical range such as "25 to 500°C" is expressed, both the lower limit and the upper limit are included in the range. For example, "25 to 500°C" means "25°C or higher and 500°C or lower." The same applies to other numerical ranges. In this specification, the processing temperature refers to the temperature of the wafer 200 or the temperature inside the processing chamber 201, and the processing pressure refers to the pressure inside the processing chamber 201. The processing time refers to the time the processing continues. In addition, when the supply flow rate includes 0 slm, 0 slm means that the substance is not supplied. These also apply to the following explanations.

[0055] As the first modifier, for example, a substance in which hydrogen (H) and an amino group are bonded to Si (aminosilane, etc.), such as tris(dimethylamino)silane (Si[N(CH3)2]3H), bis(diethylamino)silane (Si[N(C2H5)2]2H2), bis(tertiarybutylamino)silane (SiH2[NH(C4H9)]2), (diisobutylamino)silane (SiH3[N(C4H9)2]), or (diisopropylamino)silane (SiH3[N(C3H7)2]), can be used.

[0056] Furthermore, as the first modifier, for example, a substance in which an amino group and a hydrocarbon group are bonded to Si (such as an alkylaminosilane), such as (dimethylamino)trimethylsilane ((CH3)2NSi(CH3)3), (diethylamino)triethylsilane ((C2H5)2NSi(C2H5)3), (dimethylamino)triethylsilane ((CH3)2NSi(C2H5)3), (diethylamino)trimethylsilane ((C2H5)2NSi(CH3)3), or (dipropylamino)trimethylsilane ((C3H7)2NSi(CH3)3), can be used.

[0057] The first modifier may be, for example, a halogen-containing substance such as fluorine (F), chlorine (Cl), bromine (Br), or iodine (I).The halogen-containing substance used as the first modifier may be, for example, a fluorine (F)-containing substance such as fluorine (F), nitrogen trifluoride (NF), chlorine trifluoride (ClF), chlorine fluoride (ClF), or hydrogen fluoride (HF).

[0058] As the first modifier, one or more of these can be used.

[0059] As the inert gas, for example, nitrogen (N2) gas or a rare gas such as argon (Ar) gas, helium (He) gas, neon (Ne) gas, or xenon (Xe) gas can be used. One or more of these can be used as the inert gas. This also applies to each step described below.

[0060] [Step A2] In this step, valve 243b is opened to allow a film forming agent (first film forming agent) to flow into gas supply pipe 232b. The first film forming agent has its flow rate adjusted by MFC 241b, is supplied into processing chamber 201 via nozzle 249b, and is exhausted from exhaust port 231a. At this time, the first film forming agent is supplied onto wafer 200 from the side of wafer 200, and wafer 200 is exposed to the first film forming agent (first film forming agent supply, exposure). At this time, valves 243f to 243h may be opened to supply an inert gas into processing chamber 201 via nozzles 249a to 249c, respectively.

[0061] By performing this step under the processing conditions described below, at least a portion of the molecular structure of the molecules constituting the first film-forming agent can be adsorbed onto the surfaces of the first and second underlayers, forming an adsorption layer (first layer) of the first film-forming agent on these surfaces. As described above, by performing step A1, the surface of the second underlayer is modified to a surface having a first termination (a surface having a film-formation inhibiting effect). As a result, the amount of the first film-forming agent adsorbed onto the first underlayer per unit area and unit time is greater than the amount of the first film-forming agent adsorbed onto the second underlayer per unit area and unit time. In other words, the thickness of the first layer formed on the first underlayer is greater than the thickness of the first layer formed on the second underlayer.

[0062] After the first layer is formed on the first underlayer to a thickness greater than that of the first layer formed on the second underlayer, the valve 243a is closed to stop the supply of the first film forming agent to the wafer 200. Then, by the above-described procedure, gaseous substances remaining in the processing chamber 201 are removed from the processing chamber 201, and the processing chamber 201 is purged with an inert gas (purging).

[0063] The processing conditions for supplying the first film-forming agent in step A2 are as follows: Treatment temperature: room temperature (25°C) to 500°C, preferably 350 to 400°C Treatment pressure: 1 to 2000 Pa, preferably 1 to 1333 Pa Treatment time: 1 to 180 seconds, preferably 10 to 120 seconds First film-forming agent supply flow rate: 0.001 to 2 slm, preferably 0.01 to 1 slm Inert gas supply flow rate (per gas supply pipe): 0 to 20 slm is exemplified.

[0064] The first film-forming agent may be, for example, a substance (e.g., an organic metal or a metal halide) containing a metal element as a first predetermined element, such as aluminum (Al), titanium (Ti), hafnium (Hf), zirconium (Zr), etc. The first film-forming agent may be, for example, aluminum trichloride (AlCl3), trimethylaluminum (Al(CH3)3), titanium tetrachloride (TiCl4), hafnium tetrafluoride (HfCl4), tetrakisethylmethylaminohafnium (Hf[N(CH3)(CH2CH3)]4), zirconium tetrafluoride (ZrCl4), tetrakisethylmethylaminozirconium (Zr[N(CH3)Cp]4), etc.

[0065] [Step A3] In this step, the valve 243c is opened to allow a reactant (first reactant) to flow into the gas supply pipe 232c. The first reactant is adjusted in flow rate by the MFC 241c, supplied into the processing chamber 201 via the nozzle 249c, and exhausted from the exhaust port 231a. At this time, the first reactant is supplied to the wafer 200 from the side of the wafer 200, and the wafer 200 is exposed to the first reactant (first reactant supply, exposure). At this time, the valves 243f to 243h may be opened to supply an inert gas into the processing chamber 201.

[0066] By performing this step under the processing conditions described below, the first layer formed on each surface of the first underlayer and the second underlayer can be changed. For example, when an oxidizing agent is used as the first reactant, at least a portion of the first layer can be oxidized to form an oxide layer (first oxide layer) containing the constituent elements of the first film-forming agent on each surface of the first underlayer and the second underlayer. For example, when a nitriding agent is used as the first reactant, at least a portion of the first layer can be nitrided to form a nitride layer (first nitride layer) containing the constituent elements of the first film-forming agent on each surface of the first underlayer and the second underlayer.

[0067] After the first layers formed on the surfaces of the first and second underlayers are converted, the valve 243c is closed to stop the supply of reactants to the wafer 200. Then, by the above-described procedure, gaseous substances remaining in the processing chamber 201 are removed from the processing chamber 201, and the processing chamber 201 is purged with an inert gas.

[0068] The processing conditions for supplying the first reactant in step A3 are: Treatment pressure: 1 to 4000 Pa, preferably 1 to 1333 Pa First reactant supply flow rate: 0.01 to 20 slm, preferably 0.01 to 10 slm Other processing conditions may be the same as the processing conditions when the first film-forming agent is supplied in step A2.

[0069] The first reactant can be an oxidizing agent, such as oxygen (O), ozone (O), water vapor (H), nitrous oxide (N), nitric oxide (NO), nitrogen dioxide (NO), carbon dioxide (CO), or carbon monoxide (CO). The first reactant can be one or more of these oxygen (O)-containing substances.

[0070] The first reactant may be a nitriding agent, such as ammonia (NH), diazene (N2H2), hydrazine (N2H4), or hydrogen nitride such as N3H8. One or more of these nitrogen (N)-containing substances may be used as the first reactant.

[0071] [Perform the specified number of times] Then, the cycle including steps A2 and A3 is repeated a predetermined number of times (n A times. n A is an integer of 1 or greater). As a result, as shown in FIG. 4(c), a first film can be formed on each surface of the first and second underlayers. As described above, in step A2, the thickness of the first layer formed on the first underlayer is greater than the thickness of the first layer formed on the second underlayer. Therefore, by performing a cycle including steps A2 and A3 a predetermined number of times, the thickness of the first film formed on the first underlayer is greater than the thickness of the first film formed on the second underlayer.

[0072] When a substance containing the above-mentioned metal element is used as the first film-forming agent, a film containing the above-mentioned metal element can be formed as the first film.

[0073] Furthermore, when a substance containing the above-mentioned metal element is used as the first film-forming agent and the above-mentioned oxidizing agent is used as the first reactant, a film containing the above-mentioned metal element and O (i.e., a metal oxide film) can be formed as the first film. In this embodiment, more preferred examples of the first film that can be formed include oxide dielectric films (oxide high-k films) having a higher electron trap density than a SiN film, such as an aluminum oxide film (AlO film), a titanium oxide film (TiO film), a hafnium oxide film (HfO film), and a zirconium oxide film (ZrO film).

[0074] Furthermore, when a substance containing the above-mentioned metal element is used as the first film-forming agent and the above-mentioned nitriding agent is used as the first reactant, a film containing the above-mentioned metal element and N (i.e., a metal nitride film) can be formed as the first film. In this embodiment, a nitride dielectric film (nitride high-k film) having a higher electron trap density than a SiN film, such as an aluminum nitride film (AlN film), a titanium nitride film (TiN film), a hafnium nitride film (HfN film), or a zirconium nitride film (ZrN film), can be more preferably formed as the first film.

[0075] (Step B) Subsequently, the following steps B1 and B2 are performed.

[0076] [Step B1] In this step, the valve 243c is opened to allow a reactant (second reactant) to flow into the gas supply pipe 232c. The flow rate of the second reactant is adjusted by the MFC 241c, and the second reactant is supplied into the processing chamber 201 via the nozzle 249c and exhausted from the exhaust port 231a. At this time, the second reactant is supplied to the wafer 200 from the side of the wafer 200, and the wafer 200 is exposed to the second reactant (second reactant supply, exposure). At this time, the valves 243f to 243h may be opened to supply an inert gas into the processing chamber 201.

[0077] By performing this step under the processing conditions described below, the surface of the first film formed in the recess in step A can be reacted with the second reactant, forming an altered layer having a predetermined composition and a predetermined thickness on the surface of the first film. For example, if the first film is composed of an aluminum oxide (Al2O3)-based film (AlO film), supplying boron (B) and a halogen-containing substance as the second reactant to this film causes the first film to react with the second reactant, thereby modifying (converting) a portion of the surface of the first film into an altered layer of a predetermined thickness containing aluminum halide (e.g., AlCl3). This reaction can proceed uniformly across substantially the entire surface of the first film, and the composition and thickness of the altered layer become substantially uniform across the entire surface of the first film.

[0078] After forming an altered layer on the surface of the first film due to a reaction with the second reactant, the valve 243d is closed to stop the supply of the second reactant to the wafer 200. Then, the processing chamber 201 is evacuated to remove gaseous substances remaining in the processing chamber 201. Furthermore, the valves 243f to 243h are opened to supply an inert gas into the processing chamber 201 to purge the processing chamber 201 (purge).

[0079] The processing conditions for supplying the second reactant in step B1 are as follows: Treatment temperature: 200 to 900°C, preferably 300 to 800°C Treatment pressure: 150 to 400 Pa, preferably 200 to 300 Pa Treatment time: 5 to 300 seconds, preferably 100 to 200 seconds Second reactant supply flow rate: 0.001 to 2 slm, preferably 0.01 to 1 slm Inert gas supply flow rate (per gas supply pipe): 0 to 20 slm is exemplified.

[0080] The second reactant can be, for example, boron trichloride (BCl), boron trifluoride (BF), boron tribromide (BBr), boron triiodide (BI), etc. One or more of these B and halogen element-containing substances can be used as the second reactant.

[0081] [Step B2] In this step, the valve 243d is opened to allow the etching agent to flow into the gas supply pipe 232d. The etching agent has a flow rate adjusted by the MFC 241d, is supplied into the processing chamber 201 through the nozzle 249a, and is exhausted from the exhaust port 231a. At this time, the etching agent is supplied to the wafer 200 from the side of the wafer 200, and the wafer 200 is exposed to the etching agent (etching agent supply, exposure). At this time, the valves 243f to 243h may be opened to supply an inert gas into the processing chamber 201.

[0082] By carrying out this step under the processing conditions described below, the altered layer formed on the surface of the first film is reacted with the etching agent, and at least a part of the altered layer is converted into a volatile substance, which is then desorbed from the surface of the first film. For example, when an altered layer containing aluminum halide is formed on the surface of the first film, a halogen-containing substance different from the second reactant is supplied to this film as an etching agent, and the altered layer is reacted with the etching agent, and at least a part of the altered layer is converted into another aluminum halide (e.g., AlCl), which is a volatile substance. x F y The first film is converted into a fluorine-containing compound (fluorine-containing compound), which is then desorbed from the first film. As a result, the surface of the first film is etched to a substantially uniform thickness across the entire surface. The amount of etching (etching depth) of the first film formed on the first underlayer and the amount of etching (etching depth) of the first film formed on the second underlayer are substantially equal to each other.

[0083] After etching the surface of the first film, the valve 243c is closed to stop the supply of the etching agent to the wafer 200. Then, the processing chamber 201 is evacuated to remove gaseous substances remaining in the processing chamber 201 from the processing chamber 201. Furthermore, the valves 243f to 243h are opened to supply an inert gas into the processing chamber 201 to purge the processing chamber 201 (purge).

[0084] The processing conditions when supplying the etching agent in step B2 are as follows: Processing time: 5 to 200 seconds, preferably 60 to 150 seconds Etching agent supply flow rate: 0.1 to 10 slm Inert gas supply flow rate (per gas supply pipe): 0 to 20 slm Other processing conditions may be the same as those used when supplying the second reactant in step B1.

[0085] As the etching agent, for example, a halogen-containing substance can be used. As the halogen-containing substance used as the etching agent, for example, HF, F2, Cl2, NF3, ClF3, ClF, etc. can be used. As the etching agent, one or more of these halogen-containing substances can be used.

[0086] [Perform the specified number of times] Then, the cycle including steps B1 and B2 is repeated a predetermined number of times (n B times. n B is an integer of 1 or 2 or more). This makes it possible to remove the first film formed on the second underlayer while leaving at least a portion of the first film formed on the first underlayer remaining, as shown in FIG. 4(d). This is possible because, as described above, in step A, the thickness of the first film formed on the first underlayer is made thicker than the thickness of the first film formed on the second underlayer, and in step B, the amount of etching (etching depth) of the first film formed on the first underlayer and the amount of etching (etching depth) of the first film formed on the second underlayer are made approximately equal.

[0087] (Step C) Subsequently, the following steps C1 to C3 are performed.

[0088] [Step C1] In this step, a modifying agent (second modifying agent) is supplied to the wafer 200 using the same processing procedure and conditions as in step A1 described above (second modifying agent supply, exposure).

[0089] By performing this step under the processing conditions described below, as shown in FIG. 4(e), it is possible to selectively adsorb at least a portion of the molecular structure of the molecules constituting the second modifier onto the surface of the second base, which is exposed by removing the first film, relative to the surface of the first film remaining on the first base, thereby forming a predetermined adsorption layer (second inhibitor layer). By using the substance exemplified as the first modifier in step A1 as the second modifier and forming the second inhibitor layer on the surface of the second base, the surface of the second base is selectively modified to a surface terminated with hydrocarbon groups, H, F, etc., relative to the surface of the first film remaining on the first base. These terminations (hydrocarbon group termination, H termination, F termination, etc.) function as inhibitors that suppress adsorption of the second film-forming agent onto the surface of the second base in step C2 described below. That is, by performing this step, the surface of the second base is modified to a surface formed with second terminations that selectively suppress adsorption of at least a portion of the second film-forming agent relative to the surface of the first film remaining on the first base.

[0090] Note that if both the second underlayer and the first film are made of oxide, the above-mentioned selectivity may be difficult to achieve. Therefore, to enhance this selectivity, it is preferable to set the density of the material constituting the second underlayer higher than that of the first film. By relatively increasing the density of the material constituting the second underlayer, the density of terminations that serve as adsorption sites for the second modifier (e.g., hydroxyl groups (OH groups)) on the surface of the second underlayer can be made higher than the density of terminations that serve as adsorption sites for the second modifier on the surface of the first film. In other words, this increases the selectivity of adsorption of the second modifier to the surface of the second underlayer compared to adsorption to the surface of the first film. One method for increasing the density of the material constituting the second underlayer relative to that of the first film is, for example, to increase the processing temperature when forming the second underlayer higher than the processing temperature when forming the first film (i.e., the processing temperature in step A).

[0091] After the surface of the second base is selectively modified, the valve 243a is closed to stop the supply of the second modifying agent to the wafer 200. Then, the processing chamber 201 is evacuated to remove gaseous substances remaining in the processing chamber 201. Furthermore, the valves 243f to 243h are opened to supply an inert gas into the processing chamber 201, thereby purging the processing chamber 201 (purging).

[0092] [Step C2] In this step, valves 243b and 243e are opened to allow a film-forming agent (second film-forming agent) and a catalyst to flow into gas supply pipes 232b and 232e, respectively. The second film-forming agent and catalyst are supplied into processing chamber 201 via nozzle 249b at flow rates adjusted by MFCs 241b and 241e, and are exhausted from exhaust port 231a. At this time, the second film-forming agent and catalyst are supplied onto wafer 200 from the side of wafer 200, and wafer 200 is exposed to the second film-forming agent and catalyst (second film-forming agent + catalyst supply and exposure). At this time, valves 243f to 243h may be opened to supply an inert gas into processing chamber 201.

[0093] By performing this step under the processing conditions described below, at least a portion of the molecular structure of the molecules constituting the second film-forming agent can be selectively adsorbed onto the surface of the first film remaining on the first underlayer, thereby selectively forming an adsorption layer (second layer) of the second film-forming agent. As described above, by performing step C1, the surface of the second underlayer is modified to a surface having a second termination (a surface having a film-formation inhibiting effect). As a result, the formation of the second layer proceeds selectively on the surface of the first film remaining on the first underlayer relative to the second underlayer.

[0094] After the second layer is selectively formed on the surface of the first film, the valves 243b and 243e are closed to stop the supply of the second film-forming agent and catalyst to the wafer 200. Then, by the above-described procedure, gaseous substances remaining in the processing chamber 201 are removed from the processing chamber 201, and the processing chamber 201 is purged with an inert gas (purging).

[0095] The processing conditions for supplying the second film-forming agent and the catalyst in step C2 are as follows: Treatment temperature: room temperature (25°C) to 200°C, preferably room temperature to 150°C Treatment pressure: 1 to 2000 Pa, preferably 1 to 1333 Pa Treatment time: 1 to 180 seconds, preferably 10 to 120 seconds Second film-forming agent supply flow rate: 0.001 to 2 slm, preferably 0.01 to 1 slm Catalyst supply flow rate: 0.001 to 2 slm, preferably 0.01 to 1 slm Inert gas supply flow rate (per gas supply pipe): 0 to 20 slm is exemplified.

[0096] The second film-forming agent may be a substance containing a second predetermined element, particularly a non-metallic element (including a metalloid element). For example, a Si-containing substance containing silicon (Si) as the second predetermined element may be used as the second film-forming agent. For example, a substance containing a halogen element and Si, i.e., a halosilane, may be used as the second film-forming agent. For example, a substance containing Cl and Si, i.e., a chlorosilane, may be used as the halosilane.

[0097] Examples of the second film-forming agent that can be used include chlorosilanes such as monochlorosilane (SiH3Cl), dichlorosilane (SiH2Cl2), trichlorosilane (SiHCl3), tetrachlorosilane (SiCl4), hexachlorodisilane (Si2Cl6), and octachlorotrisilane (Si3Cl8); fluorosilanes such as tetrafluorosilane (SiF4) and difluorosilane (SiH2F2); bromosilanes such as tetrabromosilane (SiBr4) and dibromosilane (SiH2Br2); and iodosilanes such as tetraiodosilane (SiI4) and diiodosilane (SiH2I2).

[0098] In addition to these, the second film-forming agent may also be, for example, a substance containing an amino group and Si, i.e., an aminosilane. For example, the second film-forming agent may also be an aminosilane such as tetrakis(dimethylamino)silane (Si[N(CH3)2]4), tris(dimethylamino)silane, bis(diethylamino)silane, bis(tert-butylamino)silane, or (diisopropylamino)silane.

[0099] As the second film-forming agent, one or more of these can be used.

[0100] Examples of the catalyst that can be used include pyridine (C5H5N), picoline (C6H7N), lutidine (C7H9N), triethylamine ((C2H5)3N), etc. One or more of these amines can be used as the catalyst.

[0101] [Step C3] In this step, valves 243c and 243e are opened to allow a reactant (third reactant) and a catalyst to flow into gas supply pipes 232c and 232e, respectively. The flow rates of the third reactant and catalyst are adjusted by MFCs 241c and 241e, and the third reactant and catalyst are supplied into the processing chamber 201 via nozzles 249c and 249b and exhausted from the exhaust port 231a. At this time, the third reactant and catalyst are supplied to the wafer 200 from the side of the wafer 200, and the wafer 200 is exposed to the third reactant and catalyst (third reactant + catalyst supply and exposure). At this time, valves 243f to 243h may be opened to supply an inert gas into the processing chamber 201.

[0102] By performing this step under the processing conditions described below, the second layer formed on the surface of the first film remaining on the first underlayer can be changed. For example, when an oxidizing agent is used as the third reactant, at least a portion of the second layer can be oxidized to form an oxide layer (second oxide layer) containing the constituent elements of the second film-forming agent on the surface of the first film remaining on the first underlayer. Also, for example, when a nitriding agent is used as the third reactant, at least a portion of the second layer can be nitrided to form a nitride layer (second nitride layer) containing the constituent elements of the second film-forming agent on the surface of the first film remaining on the first underlayer.

[0103] After the second layer selectively formed on the surface of the first film is changed, the valves 243c and 243e are closed to stop the supply of the third reactant and catalyst to the wafer 200. Then, by the above-described procedure, gaseous substances remaining in the processing chamber 201 are removed from the processing chamber 201, and the processing chamber 201 is purged with an inert gas.

[0104] The process conditions for supplying the reactants and catalyst in step C3 are as follows: Treatment pressure: 1 to 4000 Pa, preferably 1 to 1333 Pa Third reactant supply flow rate: 0.001 to 2 slm, preferably 0.01 to 1 slm Catalyst supply flow rate: 0.001 to 2 slm, preferably 0.01 to 1 slm Other processing conditions may be the same as those used when supplying the film-forming agent and catalyst in step C2.

[0105] As the third reactant, one or more of the oxidizing agents and nitriding agents exemplified in step A3 can be used.

[0106] As the catalyst, one or more of the catalysts exemplified in step C2 can be used.

[0107] [Perform the specified number of times] Then, the cycle including steps C2 and C3 is repeated a predetermined number of times (n C times. n Cis an integer of 1 or 2 or more). As a result, as shown in FIG. 4(f), a second film can be formed on the first film remaining on the first underlayer. As described above, in step C2, the formation of the second layer proceeds on the surface of the first film remaining on the first underlayer selectively with respect to the second underlayer. Therefore, the formation of the second film by performing a cycle including steps C2 and C3 a predetermined number of times proceeds on the surface of the first film remaining on the first underlayer selectively with respect to the second underlayer.

[0108] When a substance containing the above-mentioned non-metallic elements, particularly semi-metallic elements, is used as the second film-forming agent, a film having a different composition from the first film, i.e., a film containing a non-metallic element such as Si, can be formed as the second film.

[0109] Furthermore, when a substance containing the above-mentioned non-metallic element is used as the second film-forming agent and the above-mentioned oxidizing agent is used as the third reactant, a Si-containing oxide film (a film containing a non-metallic element and O), such as an SiO film, SiON film, SiOC film, SiOCN film, SiBON film, or SiBCON film, can be formed as the second film.

[0110] Furthermore, when a substance containing the above-mentioned non-metallic element is used as the second film-forming agent and the above-mentioned nitriding agent is used as the third reactant, a Si-containing nitride film (a film containing a non-metallic element and N), such as a SiN film, a SiCN film, or a SiBCN film, can be formed as the second film.

[0111] (After purging and atmospheric pressure recovery) After step C is completed, an inert gas is supplied as a purge gas from each of the nozzles 249a to 249c into the processing chamber 201 and exhausted from the exhaust port 231a. This purges the processing chamber 201, and gases and reaction by-products remaining in the processing chamber 201 are removed from the processing chamber 201 (after-purge). Thereafter, the atmosphere in the processing chamber 201 is replaced with the inert gas (inert gas replacement), and the pressure in the processing chamber 201 is returned to normal pressure (atmospheric pressure return).

[0112] (Boat unloading and wafer discharging) Thereafter, the seal cap 219 is lowered by the boat elevator 115, and the lower end of the manifold 209 is opened. Then, the processed wafers 200, supported by the boat 217, are unloaded from the lower end of the manifold 209 to the outside of the reaction tube 203 (boat unloading). After the boat unloading, the shutter 219s is moved, and the opening at the lower end of the manifold 209 is sealed by the shutter 219s via the O-ring 220c (shutter close). After being unloaded to the outside of the reaction tube 203, the processed wafers 200 are removed from the boat 217 (wafer discharge).

[0113] Steps A to C are preferably performed in the same processing chamber or in multiple processing chambers connected via a transfer chamber under vacuum or a non-oxidizing atmosphere (i.e., in-situ). If the series of processes is performed in-situ, the wafer 200 is not exposed to the atmosphere during the process, and the wafer 200 can be processed consistently while being placed under vacuum or a non-oxidizing atmosphere, making it possible to perform the process without causing natural oxidation of the surface.

[0114] (3) Effects of this mode According to this aspect, one or more of the following effects can be obtained.

[0115] (a) By performing the above-described steps A and B, it is possible to precisely form a film in a recess provided on the surface of a substrate. That is, in a recess having a bottom surface formed by a first underlayer and a side surface formed by a second underlayer, it is possible to form a first film on the first underlayer selectively with respect to the second underlayer.

[0116] (b) In step B, by performing a cycle including steps B1 and B2 a predetermined number of times, it becomes possible to selectively remove the first film from the second underlayer with good controllability while leaving at least a portion of the first film formed on the first underlayer remaining. In other words, it becomes possible to selectively form the first film on the first underlayer with more precision.

[0117] (c) In step A, by performing step A1 of selectively modifying the surface of the second underlayer to a surface having a first termination before supplying the first film-forming agent to the substrate, it becomes easier to form the first film on the first underlayer with a thickness greater than that of the first film formed on the second underlayer. As a result, it becomes possible to selectively form the first film on the first underlayer with greater precision.

[0118] (d) In step A, after performing step A1, a cycle including steps A2 and A3 is performed a predetermined number of times, thereby enabling precise control of the thickness of the first film formed in the recess. As a result, selective formation of the first film on the first underlayer can be performed more precisely.

[0119] (e) Since the first film is a film containing a metal element, it becomes possible to precisely perform the film formation process in step A and the etching process in step B. As a result, it becomes possible to selectively form the first film on the first underlayer with greater precision.

[0120] The same effect can be obtained by using the first film as a film containing a metal element and O. Furthermore, the first film can be used as an oxide high-k film with a large dielectric constant.

[0121] The same effect can be obtained by using the first film containing a metal element and N. Also, the first film can be used as a nitride high-k film with a large dielectric constant. Furthermore, since the first film does not contain oxygen, it is possible to avoid oxidation of the first underlayer when performing step A.

[0122] (f) By performing step C after performing step B, it becomes possible to form a second film having a different composition from the first film on the first film remaining on the first underlayer.

[0123] (g) In step C, by performing step C1 of modifying the surface of the second base to a surface having a second termination before supplying the second film-forming agent to the substrate, it becomes possible to more precisely selectively form the second film on the first film remaining on the first base.

[0124] (h) In step C, after performing step C1, a cycle including steps C2 and C3 is performed a predetermined number of times, thereby enabling precise control of the thickness of the second film formed in the recess. As a result, selective formation of the second film on the first film can be performed more precisely.

[0125] (i) In step A, a film containing a metal element and O is formed as the first film, and in step C, a film containing a non-metal element and O is formed as the second film, thereby making it possible to selectively form a stacked structure of these films on the first base.

[0126] The same effect can be obtained by forming a film containing a metal element and N as the first film in step A, and forming a film containing a non-metal element and O as the second film in step C. Furthermore, in step A, since the first film to be formed does not contain oxygen, it is possible to avoid oxidation of the first underlayer.

[0127] The same effect can be obtained by forming a film containing a metal element and N as the first film in step A, and forming a film containing a non-metal element and N as the second film in step C. Furthermore, in step A, since the first film does not contain oxygen, it is possible to avoid oxidation of the first underlayer, and in step C, since the second film to be formed does not contain oxygen, it is possible to avoid oxidation of the first film and the first underlayer.

[0128] (j) When the second underlayer is a film containing O, performing step A1 makes it easy to modify the surface of the second underlayer into a surface on which the first termination is formed, thereby enabling more precise selective formation of the first film on the first underlayer.

[0129] Furthermore, when the second underlayer is a film containing O, performing step C1 makes it easy to modify the surface of the second underlayer into a surface on which the second termination is formed. As a result, it becomes possible to more precisely selectively form the second film on the first film remaining on the first underlayer.

[0130] (k) If the first film is used as, for example, a film that constitutes a charge trap layer of a memory cell, it is possible to improve the performance of a flash memory device.

[0131] (l) By making the thickness of the first underlayer thinner than the thickness of the first film on the first underlayer after step B is performed, when the first film is used as a film that constitutes the charge trap layer of a memory cell, it is possible to reduce interference between adjacent charge trap layers and improve the performance of the flash memory device.

[0132] (m) The above-mentioned effects can be similarly obtained when a predetermined substance is arbitrarily selected from the various modifiers, film-forming agents, reactants, etching agents, and inert gases mentioned above.

[0133] (4) Variations This aspect can be modified as follows: The following modifications can be combined in any manner.

[0134] (Variation 1) After performing step C, step D may be performed in which an oxidizing agent is supplied to the substrate as a reactant (fourth reactant) using a procedure similar to step A3.

[0135] The processing conditions for supplying the oxidizing agent in step D are as follows: Treatment temperature: 350 to 1000°C, preferably 400 to 650°C Treatment pressure: 1 to 105,000 Pa, preferably 10 to 10,000 Pa Treatment time: 1 to 10,000 seconds, preferably 5 to 3,600 seconds Oxidant supply flow rate: 0.01 to 10 slm, preferably 0.1 to 5 slm Inert gas supply flow rate (per gas supply pipe): 0 to 20 slm is exemplified.

[0136] Examples of oxidizing agents that can be used include oxygen-containing substances with strong oxidizing power, such as ozone (O), oxygen (O) + hydrogen (H), O + deuterium (D), O + H, O + D, water vapor (H), hydrogen peroxide (H), and plasma-excited O or O. One or more of these can be used as the oxidizing agent. Here, the combination of two substances, such as "O + H," refers to a mixture of O and H. When supplying a mixture, the two substances may be mixed (premixed) in a supply pipe and then supplied into the processing chamber 201. Alternatively, the two substances may be supplied separately from different supply pipes into the processing chamber 201 and mixed (postmixed) in the processing chamber 201.

[0137] In this modified example, the same effects as those of the above embodiment can be obtained.

[0138] Furthermore, in the case where a metal nitride film is formed as the first film in step A, in this modified example, by performing step D, it becomes possible to modify (change) at least a portion of the first film into an oxide film such as a metal oxide film or a metal oxynitride film via the second film.

[0139] Furthermore, in the case where a metal oxide film is formed as the first film in step A, in this modified example, by performing step D, it is possible to modify (change) at least a portion of the first film into a denser oxide film with fewer impurities via the second film.

[0140] Furthermore, in this modified example, by modifying (oxidizing) the first film through the second film, it is possible to modify (change) at least a portion of the second film into a denser oxide film with fewer impurities.

[0141] (Variation 2) In step C, an oxidizing agent having a strong oxidizing power, such as O3, O2 + H2, O2 + D2, O3 + H2, O3 + D2, H2O2, or O2 or O3 excited to a plasma state, may be used as the reactant (third reactant). The processing conditions may be the same as those used in supplying the oxidizing agent in step D of the first modification.

[0142] In this modified example, the same effects as those of the above embodiment can be obtained.

[0143] Furthermore, in this modification, when a metal nitride film is formed as the first film in step A, by performing step C using an oxidizing agent with strong oxidizing power, when the second film is formed, it becomes possible to modify (change) at least a portion of the first film, which is the base film, into an oxide film such as a metal oxide film or a metal oxynitride film.

[0144] Furthermore, in this modified example, when a metal oxide film is formed as the first film in step A, by performing step C using an oxidizing agent with strong oxidizing power, it is possible to modify (change) at least a portion of the first film into a denser oxide film with fewer impurities.

[0145] Furthermore, in this modification, by performing step C using an oxidizing agent having a strong oxidizing power as the third reactant, it is possible to make the second film a dense oxide film with few impurities.

[0146] (Variation 3) After performing step B and before performing step C, step E may be performed in which an oxidizing agent containing O and H, such as HO or HO, is supplied to the substrate as a reactant (fifth reactant) using the same processing procedure and processing conditions as step A3.

[0147] In this modified example, the same effects as those of the above embodiment can be obtained.

[0148] Furthermore, in this modification, after performing step B and before performing step C, step E is performed in which an oxidizing agent containing O and H is supplied to the substrate, thereby removing halogen elements (Cl, F, etc.) that have been adsorbed and remained on the surface of the second underlayer by performing step B, and terminating the surface of the second underlayer with OH groups. This makes it possible to efficiently perform selective termination of the second underlayer in step C1.

[0149] (Variation 4) In step B, the first film may be etched using the etchant alone, without using the second reactant.

[0150] In this case, the supply of the etching agent may be carried out intermittently a plurality of times, or may be carried out continuously.

[0151] These modifications also provide the same effects as those of the above embodiment.

[0152] <Other Aspects of the Present Disclosure> Although the embodiments of the present disclosure have been specifically described above, the present disclosure is not limited to the above embodiments and can be modified in various ways without departing from the spirit and scope of the present disclosure.

[0153] In the above-described embodiment, an example was described in which a metal oxide film or a metal nitride film is formed using a substance containing a metal element as the first film-forming agent in step A. The present disclosure is not limited to the above-described embodiment and can be applied, for example, to a case in which a substance containing a nonmetal element, particularly one of the above-described metalloid elements, is used as the first film-forming agent in step A to form an oxide film or nitride film containing these elements. Furthermore, in the above-described embodiment, an example was described in which a substance containing a nonmetal element is used as the second film-forming agent in step C to form an oxide film or nitride film containing nonmetal elements. The present disclosure is not limited to the above-described embodiment and can be applied, for example, to a case in which a substance containing one of the above-described metal elements is used as the second film-forming agent in step C to form an oxide film or nitride film containing these metal elements.

[0154] It is preferable that the recipes used for each process are individually prepared according to the process content and recorded and stored in the storage device 121c via an electric communication line or an external storage device 123. Then, when starting each process, it is preferable that the CPU 121a appropriately selects an appropriate recipe according to the process content from the multiple recipes recorded and stored in the storage device 121c. This enables the processing device to reproducibly form films with various film types, composition ratios, film qualities, and film thicknesses. It also reduces the burden on the operator, prevents operational errors, and enables each process to be started quickly.

[0155] The above-mentioned recipes do not necessarily have to be newly created, but may be prepared by modifying an existing recipe that has already been installed in the processing device. When modifying a recipe, the modified recipe may be installed in the processing device via an electric communication line or a recording medium on which the recipe has been recorded. Alternatively, an existing recipe that has already been installed in the processing device may be directly modified by operating the input / output device 122 provided in the existing processing device.

[0156] In the above-described embodiment, an example of film formation processing using a batch-type processing apparatus that processes multiple substrates at a time has been described. The present disclosure is not limited to the above-described embodiment, and can be suitably applied, for example, to a case where film formation processing is performed using a single-wafer processing apparatus that processes one or several substrates at a time. Furthermore, in the above-described embodiment, an example of film formation processing using a processing apparatus having a hot-wall processing furnace has been described. The present disclosure is not limited to the above-described embodiment, and can be suitably applied to a case where film formation processing is performed using a processing apparatus having a cold-wall processing furnace.

[0157] In the above-described embodiment, an example has been described in which a series of processing sequences from steps A to C are performed in-situ. The present disclosure is not limited to the above-described embodiment. Any one of steps A to C and any other step may be performed ex-situ in different processing chambers of different processing apparatuses, or may be performed in different processing chambers of the same processing apparatus.

[0158] When using these processing devices, each process can be performed using the same processing procedures and conditions as in the above-described embodiments and modifications, and the same effects as in the above-described embodiments and modifications can be obtained.

[0159] The above-described embodiments and modifications may be used in combination as appropriate. The processing procedures and processing conditions in such a case may be the same as those of the above-described embodiments and modifications, for example. [Explanation of symbols]

[0160] 200 wafers (substrates)

Claims

1. (a) supplying a film-forming agent to a substrate having a recess on its surface, the recess having a bottom surface formed by a first underlayer and a side surface formed by a second underlayer, and forming the first film on the first underlayer to a thickness greater than that of a first film formed on the second underlayer; (b) supplying an etching agent to the substrate to remove the first film formed on the second underlayer while leaving at least a portion of the first film formed on the first underlayer; A substrate processing method comprising:

2. In the above (b), (b1) supplying the etching agent to the substrate; (b2) supplying to the substrate a second reactant, the second reactant being a substance different from the etchant and reactive with the first film; A cycle including the above is performed a predetermined number of times. The substrate processing method according to claim 1 .

3. In the step (a), before supplying the film forming agent to the substrate, (a1) supplying a modifying agent to the substrate, and modifying the surface of the second underlayer selectively with respect to the surface of the first underlayer into a surface having a first termination formed thereon that suppresses adsorption of at least a part of the film-forming agent; The substrate processing method according to claim 1 .

4. In the (a), after carrying out the (a1), (a2) supplying the film-forming agent to the substrate; (a3) providing a first reactant to the substrate; A cycle including the above is performed a predetermined number of times. The substrate processing method according to claim 3 .

5. In the step (a), a film containing a metal element is formed as the first film. The substrate processing method according to claim 1 .

6. In the step (a), a film containing a metal element and oxygen is formed as the first film. The substrate processing method according to claim 1 .

7. In the step (a), a film containing a metal element and nitrogen is formed as the first film. The substrate processing method according to claim 1 .

8. After carrying out (b), (c) supplying a second film-forming agent to the substrate to form a second film on the first film, the second film having a different composition from the first film; The substrate processing method according to claim 1 .

9. In the step (c), before the second film forming agent is supplied to the substrate, (c1) supplying a second modifying agent to the substrate, and modifying the surface of the second base selectively with respect to the surface of the first film to a surface having a second termination formed thereon that suppresses adsorption of at least a portion of the second film-forming agent; The substrate processing method according to claim 8 .

10. In the (c) step, after the (c1) step is performed, (c2) supplying the second film forming agent to the substrate; (c3) providing a third reactant to the substrate; A cycle including the above is performed a predetermined number of times. The substrate processing method according to claim 9 .

11. In the step (a), a film containing a metal element and oxygen is formed as the first film; In the step (c), a film containing a nonmetallic element and oxygen is formed as the second film. The substrate processing method according to any one of claims 8 to 10.

12. In the step (a), a film containing a metal element and nitrogen is formed as the first film; In the step (c), a film containing a nonmetallic element and oxygen is formed as the second film. The substrate processing method according to any one of claims 8 to 10.

13. In the step (a), a film containing a metal element and nitrogen is formed as the first film; In the step (c), a film containing a nonmetallic element and nitrogen is formed as the second film. The substrate processing method according to any one of claims 8 to 10.

14. The second underlayer is a film containing oxygen. The substrate processing method according to claim 12.

15. After carrying out (c), (d) supplying an oxidizing agent to the substrate to modify at least a portion of the first film into an oxide film via the second film; The substrate processing method according to claim 12.

16. The first film is a film that constitutes at least a part of a charge trap layer of a memory cell. The substrate processing method according to claim 1 .

17. The thickness of the first underlayer is thinner than the thickness of the first film on the first underlayer after the step (b) is performed. The substrate processing method according to claim 1 .

18. (a) supplying a film-forming agent to a substrate having a recess on its surface, the recess having a bottom surface formed by a first underlayer and a side surface formed by a second underlayer, and forming the first film on the first underlayer to a thickness greater than that of a first film formed on the second underlayer; (b) supplying an etching agent to the substrate to remove the first film formed on the second underlayer while leaving at least a portion of the first film formed on the first underlayer; A method for manufacturing a semiconductor device having the above structure.

19. (a) supplying a film-forming agent to a substrate having a recess on its surface, the recess having a bottom surface formed by a first underlayer and a side surface formed by a second underlayer, and forming the first film on the first underlayer to a thickness greater than that of a first film formed on the second underlayer; (b) supplying an etching agent to the substrate to remove the first film formed on the second underlayer while leaving at least a portion of the first film formed on the first underlayer; A program that causes a computer to execute the above in a substrate processing apparatus.

20. a film-forming agent supply system for supplying a film-forming agent to the substrate; an etching agent supply system for supplying an etching agent to the substrate; a control unit configured to be able to control the film-forming agent supply system and the etching agent supply system to perform the following processes: (a) supplying the film-forming agent to a substrate having a recess on a surface thereof, the recess having a bottom surface formed by a first underlayer and a side surface formed by a second underlayer, and forming the first film on the first underlayer to a thickness greater than a first film formed on the second underlayer; and (b) supplying the etching agent to the substrate, and removing the first film formed on the second underlayer while leaving at least a portion of the first film formed on the first underlayer remaining; A substrate processing apparatus having:

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