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

Abstract

To precisely form a film onto a substrate.SOLUTION: A substrate processing method includes: a step (a) of selectively forming a first sacrificial film onto a front surface of a first material and a second sacrificial film onto a front surface of a third material in relation to the surface of the second material, in a substrate having a structure where each front surface of the first, second, and third materials is adjacent sequentially; a step (b) of forming a separation film into a concave part that the first and second sacrificial films are a side wall; a step (c) of selectively removing the first and second sacrificial films to the separation film, the first material, and the third material, and thus, forming a first concave part that the front surface of the first material is a bottom surface while having a one side surface of the separation film as a side wall and a second concave part that the front surface of the second material is a bottom surface while having the other side surface of the separation film as the side wall.SELECTED DRAWING: Figure 1

Description

Technical Field

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

Background Art

[0002] As one step in the manufacturing process of a semiconductor device, a process of forming a film on the surface of a substrate may be performed (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The present disclosure provides a technology capable of precisely forming a film on a substrate.

Means for Solving the Problems

[0005] According to one aspect of the present disclosure, (a) In a substrate having a structure in which the surfaces of a first material, a second material, and a third material are adjacent to each other in this order, a first sacrificial film is selectively formed on the surface of the first material, and a second sacrificial film is selectively formed on the surface of the third material with respect to the surface of the second material; (b) forming a separation film in a recess having the first sacrificial film and the second sacrificial film as side walls; (c) selectively removing the first sacrificial film and the second sacrificial film with respect to the separation film, the first material, and the third material, thereby forming a first recess having the surface of the first material as a bottom surface and one side surface of the separation film as a side wall, and a second recess having the surface of the second material as a bottom surface and the other side surface of the separation film as a side wall. A technology having the above is provided.

Advantages of the Invention

[0006] According to the present disclosure, it becomes possible to precisely form a film on a substrate.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0008] <One Aspect of the Present Disclosure> Hereinafter, one aspect of the present disclosure will be mainly described with reference to FIGS. 1 to 3, FIGS. 4(a) to 4(e), and FIGS. 5(a) to 5(d). Note that the drawings used in the following description are all schematic, and the dimensional relationships and ratios of the respective elements shown in the drawings do not necessarily match the actual ones. Also, the dimensional relationships and ratios of the respective elements do not necessarily match among a plurality of drawings.

[0009] (1) Configuration of Substrate Processing Apparatus As shown in FIG. 1, a processing furnace 202 of a substrate processing apparatus includes a reaction tube 203. A manifold 209 is disposed below the reaction tube 203. A processing container is mainly constituted by the reaction tube 203 and the manifold 209. A processing chamber 201 is formed inside the processing container. The processing chamber 201 is configured to be able to accommodate a wafer 200 as a substrate.

[0010] Outside the reaction tube 203, a heater 207 for heating the wafer 200 in the processing chamber 201 is provided. The heater 207 also functions as an activation mechanism for activating the gas in the processing chamber 201 with heat. A temperature sensor 263 is installed in the reaction tube 203.

[0011] In the processing chamber 201, nozzles 249a to 249c are provided. As shown in FIG. 2, the nozzles 249a to 249c are provided along the inner wall of the reaction tube 203 so as to rise 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 over the lower part to the upper part 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 in the gas supply pipes 232a to 232c. Gas supply pipes 232d, 232e, and 232g are connected to the downstream side of the valve 243a in the gas supply pipe 232a. Gas supply pipes 232f and 232h are connected to the downstream side of the valve 243b in the gas supply pipe 232b. A gas supply pipe 232i is connected to the downstream side of the valve 243c in the gas supply pipe 232c. MFCs 241d to 241i and valves 241d to 241i are provided in the gas supply pipes 232d to 232i.

[0013] The first raw material is supplied from the gas supply pipe 232a into the processing chamber 201 via the MFC 241a, the valve 243a, and the nozzle 249a.

[0014] The reactant (oxidizing agent, nitriding agent) is supplied from the gas supply pipe 232b into the processing chamber 201 via the MFC 241b, the valve 243b, and the nozzle 249b.

[0015] The modifier is supplied from the gas supply pipe 232c into the processing chamber 201 via the MFC 241c, the valve 243c, and the nozzle 249c.

[0016] From the gas supply pipe 232d, the second raw material is supplied into the processing chamber 201 through the MFC241d, valve 243d, gas supply pipe 232a, and nozzle 249a.

[0017] From the gas supply pipe 232e, the third raw material is supplied into the processing chamber 201 through the MFC241e, valve 243e, gas supply pipe 232a, and nozzle 249a.

[0018] From the gas supply pipe 232f, the catalyst is supplied into the processing chamber 201 through the MFC241f, valve 243f, gas supply pipe 232b, and nozzle 249b.

[0019] From the gas supply pipes 232g to 232i, the inert gas is supplied into the processing chamber 201 through the MFC241g to 241i, valves 243g to 243i, gas supply pipes 232a to 232c, and nozzles 249a to 249c. The inert gas acts as a purge gas, carrier gas, dilution gas, etc.

[0020] Primarily, the gas supply pipe 232a, MFC 241a, and valve 243a constitute the first raw material supply system. Primarily, the gas supply pipe 232b, MFC 241b, and valve 243b constitute the reactant (oxidant, nitriding agent) supply system. Primarily, the gas supply pipe 232c, MFC 241c, and valve 243c constitute the reforming agent supply system. Primarily, the gas supply pipe 232d, MFC 241d, and valve 243d constitute the second raw material supply system. Primarily, the gas supply pipe 232e, MFC 241e, and valve 243e constitute the third raw material supply system. Primarily, the gas supply pipe 232f, MFC 241f, and valve 243f constitute the catalyst supply system. Primarily, the gas supply pipes 232g to 232i, MFCs 241g to 241i, and valves 243g to 243i constitute the inert gas supply system. Among the above-described various supply systems, any one or all of the supply systems may be configured as an integrated supply system 248 in which the valves 243a to 243i, MFCs 241a to 241i, etc. are integrated. When different reactants are used in each of the processing steps (steps A, B, D, E) described later, a reactant supply system for supplying the reactant to the nozzle 249c is individually provided for each different reactant.

[0021] Below the reaction tube 203, an exhaust port 231a is provided. To the exhaust pipe 231, a vacuum pump 246 is connected via a pressure sensor 245 and an APC (Auto Pressure Controller) valve 244. Primarily, the exhaust pipe 231, APC valve 244, and pressure sensor 245 constitute the exhaust system. The vacuum pump 246 may be included in the exhaust system.

[0022] Below the manifold 209, a seal cap 219 is provided. On the seal cap 219, a rotation mechanism 267 for rotating the boat 217 described later is installed. The seal cap 219 is raised and lowered by a boat elevator 115. The boat elevator 115 functions as a transfer mechanism for transferring the wafer 200 in and out of the processing chamber 201.

[0023] Below the manifold 209, a shutter 219s capable of hermetically closing the lower end opening of the manifold 209 is provided. The opening and closing operation of the shutter 219s is controlled by a shutter opening and closing mechanism 115s.

[0024] The boat 217 as a substrate support is configured to support a plurality of, for example, 25 to 200 wafers 200 in a multi-stage manner with their centers aligned in the vertical direction in a horizontal posture. A heat insulating plate 218 is supported in multiple stages below the boat 217.

[0025] Furthermore, the substrate processing apparatus may include a first etching unit (first etching apparatus) that executes at least one of step B2 (separation film formation) and step D2 (first dielectric film and second dielectric film formation) described later. This unit includes, for example, an etching gas supply system that supplies etching gas into a processing container that houses the wafer 200, a plasma generation unit that plasma-excites the etching gas in the processing container by an electrode (antenna) supplied with high-frequency power, a bias adjustment unit that adjusts the potential (bias) of the wafer 200, and the like. In at least one of step B2 and step D2, anisotropic plasma etching on the wafer 200 can be performed using this unit.

[0026] Furthermore, the substrate processing apparatus may include a second etching unit (second etching apparatus) that executes step C (formation of the first recess and the second recess) described later. This unit includes, for example, an etching agent supply system that supplies an etching agent (etching solution or etching gas) to the wafer 200 housed in the processing container, or an immersion container configured to immerse the wafer 200 in the etching solution. In step C, wet etching or dry etching on the wafer 200 can be performed using this unit. Note that the substrate processing apparatus including at least one of the first etching unit and the second etching unit may be configured as a processing system connected to each other via a communication network.

[0027] As shown in FIG. 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. It is possible to connect an external storage device 123 to the controller 121.

[0028] The storage device 121c is composed of a flash memory, an HDD, an SSD, or the like. In the storage device 121c, a control program for controlling the operation of the processing device, a process recipe in which procedures and conditions for substrate processing described later are described, and the like are recorded and stored so as to be readable. The process recipe is a combination of each procedure in the substrate processing described later so that the controller 121 can cause the processing device to execute it and obtain a predetermined result, and functions as a program. Hereinafter, the process recipe, the control program, and the like are collectively referred to simply as a program. Also, the process recipe is simply referred to as a recipe. When the term "program" is used in this specification, it may include only the recipe alone, only the control program alone, or both of them.

[0029] The I / O port 121d is connected to MFCs 241a to 241i, valves 243a to 243i, a pressure sensor 245, an APC valve 244, a vacuum pump 246, a temperature sensor 263, a heater 207, a rotation mechanism 267, a boat elevator 115, a shutter opening / closing mechanism 115s, and the like. The I / O port 121d may be further connected to a first etching unit and a second etching unit.

[0030] The CPU 121a is configured to read a control program from the storage device 121c and execute it, and to be able to read a recipe from the storage device 121c in response to an input of an operation command from the input / output device 122 or the like. The CPU 121a is configured to control the flow rate adjustment operations of various substances by the MFCs 241a to 241i, the opening and closing operations of the valves 243a to 243i, 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 operations of the boat 217 by the rotation mechanism 267, the lifting and lowering operations of the boat 217 by the boat elevator 115, the opening and closing operations of the shutter 219s by the shutter opening and closing mechanism 115s, etc. so as to conform to the content of the read recipe. The CPU 121a may further be configured to be able to control the first etching unit and the second etching unit.

[0031] The controller 121 can be configured by installing the above-described program recorded and stored in the external storage device 123 into a computer. The external storage device 123 includes magnetic disks such as HDDs, optical disks such as CDs, magneto-optical disks such as MOs, semiconductor memories such as USB memories and SSDs, etc. The storage device 121c and the external storage device 123 are configured as computer-readable recording media. Hereinafter, these are collectively referred to simply as recording media. When the term recording medium is used in this specification, it may include only the storage device 121c alone, only the external storage device 123 alone, or both of them. The program may be provided to the computer using communication means such as the Internet.

[0032] (2) Substrate processing step Using the above-described substrate processing apparatus and the like, as one step in the manufacturing process (manufacturing method) of a semiconductor device, an example of a processing sequence for forming a film on the surface of a wafer 200 as a substrate will be mainly described with reference to FIGS. 4(a) to 4(e) and FIGS. 5(a) to 5(d). Among the series of processing sequences shown below, some steps (steps A1, A2, B1, D1, E) are performed by the above-described substrate processing apparatus. At this time, the operations of each part constituting the substrate processing apparatus are controlled by the controller 121.

[0033] In the processing sequence in this aspect, (a) In the wafer 200 having a structure in which the surfaces of the first material, the second material, and the third material are adjacent to each other in this order, a first sacrificial film is selectively formed on the surface of the first material and a second sacrificial film is selectively formed on the surface of the third material with respect to the surface of the second material in step A; (b) forming a separation film in a recess having the first sacrificial film and the second sacrificial film as side walls in step B; (c) By selectively removing the first sacrificial film and the second sacrificial film with respect to the separation film, the first material, and the third material, a first recess having the surface of the first material as the bottom surface with one side surface of the separation film as the side wall and a second recess having the surface of the second material as the bottom surface with the other side surface of the separation film as the side wall are formed in step C. are performed.

[0034] In the following example, in step A, as shown in FIGS. 4(a) and 4(b), (a-1) forming a first adsorption inhibition layer that inhibits the adsorption of the first raw material selectively on the surface of the second material with respect to the surfaces of the first material and the third material in step A1; (a-2) forming a first sacrificial film on the surface of the first material and a second sacrificial film on the surface of the third material, respectively, by supplying the first raw material to the wafer 200 in step A2; will be described.

[0035] Also, in the following example, in step B, as shown in FIGS. 4(c) and 4(d), (B1) Form an embedded film that fills the concave portion and covers at least a part of the upper surfaces of the first sacrificial film and the second sacrificial film; (B2) Leave the portion of the embedded film formed in the concave portion as a separation film, and remove the other portions; This case will be described.

[0036] Also, in the following example, after performing the above step C to form the first concave portion and the second concave portion on the surface of the wafer 200 as shown in FIG. 4(e), (D) This case will be further described where a first dielectric film is formed in the first concave portion and a second dielectric film is formed in the second concave portion.

[0037] Specifically, in step D, as shown in FIGS. 5(a) and 5(b), (D1) Form a dielectric film that fills the first concave portion and the second concave portion and covers at least a part of the upper surface of the separation film; (D2) Leave the portions of the dielectric film that fill the first concave portion and the second concave portion as the first dielectric film and the second dielectric film, respectively, and remove the other portions; This case will be described.

[0038] Also, in the following example, after performing step D, as shown in FIG. 5(c), By supplying an oxidizing agent to the wafer 200, a part of the first material in contact with the interface between the first material and the first dielectric film is modified to a first substitution oxide film through the first dielectric film, and a part of the third material in contact with the interface between the third material and the second dielectric film is modified to a second substitution oxide film through the second dielectric film. This case of further performing step E will be described.

[0039] Also, in the following example, after performing step E, as shown in FIG. 5(d), When further performing step F of sequentially laminating a tunnel oxide film and a channel film on the surface of the wafer 200, that is, on the surfaces of the isolation film, the first dielectric film, and the second dielectric film formed on the wafer 200, it will be described.

[0040] As used herein, the term "wafer" may mean the wafer itself or a laminate of the wafer and a predetermined layer or film formed on its surface. As used herein, the phrase "surface of the wafer" may mean the surface of the wafer itself or the surface of a predetermined layer or the like formed on the wafer. When it is described herein that "a predetermined layer is formed on the surface of the wafer", it may mean directly forming a predetermined layer on the surface of the wafer itself or forming a predetermined layer on a layer or the like formed on the wafer. When the term "substrate" is used herein, it is synonymous with the case where the term "wafer" is used.

[0041] As used herein, the terms "agent" and "substance" include at least one of gaseous substances and liquid substances. Liquid substances include mist substances. That is, each of the modifier, the first to third raw materials, and the reactants (oxidizing agent, nitriding agent) described below may contain a gaseous substance, may contain a liquid substance such as a mist substance, or may contain both of them.

[0042] Hereinafter, the processing sequence in this embodiment will be specifically described.

[0043] When a plurality of wafers 200 are loaded (wafer charge) into the boat 217, the shutter 219s is moved to open the lower end opening of the manifold 209 (shutter open). Thereafter, 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).

[0044] As shown in FIG. 4(a) and the like, the wafer 200 to be processed has, on its surface, a structure in which the surfaces of the first material, the second material, and the third material are adjacent to each other in this order (hereinafter also referred to as an adjacent structure). There may be a three-dimensional structure such as a trench or a hole provided on the surface of the wafer 200, and the above-mentioned adjacent structure may be provided on a three-dimensional portion such as the side wall surface of a trench or a hole. Further, the above-mentioned adjacent structure may be provided on a flat portion on the surface of the wafer 200. The second material can be an oxide, and each of the first material and the third material can be at least one of an oxide or a non-oxide having a smaller oxygen content ratio (that is, the ratio of oxygen in the composition of the material or the oxygen content concentration) than the second material. For example, each of the first material and the third material can be a nitride such as silicon nitride (SiN), and the second material can be an oxide such as silicon oxide (SiO). Further, each of the first material and the third material may be a material in which at least a part of the surface of a nitride such as SiN is naturally oxidized. Even in this case, the naturally oxidized surface has a smaller oxygen content ratio than the second material.

[0045] After the boat loading is completed, the processing chamber 201 is evacuated (depressurized) by the vacuum pump 246 so that the inside of the processing chamber 201 reaches a desired pressure (degree of vacuum). Further, the wafer 200 in the processing chamber 201 is heated by the heater 207 so that the wafer 200 reaches a desired processing temperature. Further, the rotation of the wafer 200 by the rotation mechanism 267 is started. The evacuation of the processing chamber 201, the heating of the wafer 200, and the rotation are all continuously performed until at least the processing of the wafer 200 is completed.

[0046] (Step A) Subsequently, the following steps A1 and A2 are performed on the wafer 200 prepared in the processing chamber 201.

[0047] [Step A1: Formation of the first adsorption inhibition layer] In this step, valve 243c is opened to supply a modifier (inhibitor) to wafer 200. At this time, valves 243g to 243i may be opened to supply an inert gas into process chamber 201.

[0048] By performing step A1 under the processing conditions described below, as shown in FIG. 4(a), a first adsorption inhibition layer (first inhibitor layer) that inhibits the adsorption of the first raw material can be selectively formed on the surface of the second material with respect to the surfaces of the first material and the third material. The first adsorption inhibition layer contains at least a part of the molecular structure of the molecules constituting the modifier. In the present disclosure, the phrase "selectively form a first adsorption inhibition layer on the surface of the second material" does not mean "form the first adsorption inhibition layer only on the surface of the second material", but means "preferably form the first adsorption inhibition layer on the surface of the second material among the surfaces of the first material, the second material, and the third material". That is, this phrase does not completely exclude the formation of the first adsorption inhibition layer on the surface of the first material or the formation of the first adsorption inhibition layer on the surface of the third material. This phrase "selectively" is used with substantially the same meaning in each of the following steps.

[0049] After selectively forming the first adsorption inhibition layer on the surface of the second material, valve 243c is closed to stop the supply of the modifier to wafer 200. Then, the inside of process chamber 201 is evacuated to remove gaseous substances and the like remaining in process chamber 201 from process chamber 201. Further, valves 243g to 243i are opened to supply an inert gas into process chamber 201 to purge process chamber 201.

[0050] As the modifier, for example, alkylaminosilanes 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), (dipropylamino)trimethylsilane ((C3H7)2NSi(CH3)3) can be used.

[0051] In addition, as the modifier, for example, aminosilanes such as tetrakis(dimethylamino)silane (Si[N(CH3)2]4), tris(dimethylamino)silane (Si[N(CH3)2]3H), bis(diethylamino)silane (Si[N(C2H5)2]2H2), bis(tert-butylamino)silane (SiH2[NH(C4H9)]2), (diisopropylamino)silane (SiH3[N(C3H7)2]) can be used.

[0052] As the modifier, one or more of these silicon (Si)-containing substances can be used.

[0053] When supplying the Si-containing substance as the modifier in Step A1, the processing conditions are as follows: Processing temperature: room temperature (25°C) to 500°C, preferably room temperature to 250°C Processing pressure: 5 to 1000 Pa Processing time: 1 second to 120 minutes, preferably 30 seconds to 60 minutes 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 are exemplified.

[0054] Note that the notation of a numerical range such as "25 to 500°C" in this specification means that the lower limit value and the upper limit value are included in that range. Therefore, for example, "0 to 500°C" means "0°C or higher and 500°C or lower". The same applies to other numerical ranges. Also, the processing temperature in this specification means the temperature of the wafer 200 or the temperature in the processing chamber 201, and the processing pressure means the pressure in the processing chamber 201. Also, the processing time means the time for which the processing is continued. Also, when 0 slm is included in the supply flow rate, 0 slm means the case where the substance is not supplied. These are the same in the following description.

[0055] In addition, as the modifier, fluorine (F2), nitrogen trifluoride (NF3), chlorine trifluoride (ClF3), hydrogen fluoride (HF), etc. can be used. As the modifier, one or more of these fluorine (F)-containing substances can be used.

[0056] When supplying the F-containing substance as the modifier in Step A1, the processing conditions are as follows: Processing temperature: room temperature (25°C) to 300°C, preferably room temperature to 200°C Processing pressure: 1 to 2000 Pa, preferably 1 to 1000 Pa Processing time: 1 second to 60 minutes Modifier supply flow rate: 0.001 to 2 slm, preferably 0.001 to 0.5 slm Inert gas supply flow rate (per gas supply pipe): 0 to 20 slm are exemplified.

[0057] In Step A1, Step A1(Si) of supplying the Si-containing substance as the modifier to the wafer 200 and Step A1(F) of supplying the F-containing substance as the modifier can be performed in this order.

[0058] [Step A2: Formation of the first sacrificial film and the second sacrificial film] In this step, after forming the first adsorption inhibition layer on the surface of the second material, the following steps (first raw material supply, reactant supply) are performed on the wafer 200. As the reactant, for example, a nitriding agent can be used.

[0059] [First raw material supply] In this step, the valve 243a is opened to supply the first raw material to the wafer 200. At this time, the valves 243g to 243i may be opened to supply an inert gas into the processing chamber 201.

[0060] By performing this step (first raw material supply) under the processing conditions described below, an adsorption layer of the first raw material can be selectively formed on the surfaces of the first material and the third material, respectively, with respect to the surface of the second material. The adsorption layer of the first raw material contains at least a part of the molecular structure of the molecules constituting the first raw material.

[0061] After forming the adsorption layer of the first raw material, close valve 243a to stop the supply of the first raw material to wafer 200. Then, by the above-described procedure, gaseous substances and the like remaining in processing chamber 201 are removed from processing chamber 201, and processing chamber 201 is purged with an inert gas (purge).

[0062] 〔Reagent supply〕 In this step, open valve 243b to supply a reagent to wafer 200. At this time, valves 243g to 243i may be opened to supply an inert gas into processing chamber 201.

[0063] By performing this step (reagent supply) under the processing conditions described below, the adsorption layer of the first raw material selectively formed on the surfaces of the first material and the third material, respectively, can be modified. When a nitriding agent is used as the reagent, the adsorption layer of the first raw material can be nitrided to form a nitride layer containing the constituent elements of the first raw material on the surfaces of the first material and the third material, respectively.

[0064] After modifying the adsorption layer of the first raw material, close valve 243b to stop the supply of the reagent to wafer 200. Then, by the above-described procedure, gaseous substances and the like remaining in processing chamber 201 are removed from processing chamber 201, and processing chamber 201 is purged with an inert gas.

[0065] 〔Perform a predetermined number of times〕 Then, a cycle including the first raw material supply and the reagent supply is repeated a predetermined number of times (n A times. n A(where \(n\) is an integer of 1 or more) By doing this, as shown in FIG. 4(b), a first sacrificial film can be selectively formed on the surface of the first material and a second sacrificial film can be selectively formed on the surface of the third material with respect to the surface of the second material. When a Si-containing substance is used as the first raw material and a nitriding agent is used as the reactant, a nitride film, for example, a silicon nitride film (SiN film), can be formed as the first sacrificial film and the second sacrificial film. Note that by forming the first sacrificial film and the second sacrificial film, a recess is formed on the surface of the wafer 200 with the first sacrificial film and the second sacrificial film as side walls and the surface of the second material as the bottom.

[0066] Note that the statement “selectively form a first sacrificial film on the surface of the first material and a second sacrificial film on the surface of the third material with respect to the surface of the second material” does not completely exclude the formation of the first sacrificial film and the second sacrificial film on the surface of the second material as described above. Therefore, for example, due to a part of the adsorption inhibition layer desorbing during the process of step A2, a discontinuous nitride layer may be formed on a part of the surface of the second material. Also, for example, as shown in FIG. 4(b), in step A2, the first sacrificial film can be formed so as to protrude (overflow, cover, cross the border) to the side of the surface of the second material rather than the boundary between the surface of the second material and the surface of the first material. This is because during the process of repeating the cycle of forming the first sacrificial film, the first sacrificial film itself can grow so as to protrude above the second material with the first sacrificial film as a base. Also, for example, in step A2, the second sacrificial film can be formed so as to protrude (overflow, cover, cross the border) to the side of the surface of the second material rather than the boundary between the surface of the second material and the surface of the third material in the same manner as the first sacrificial film. When the discontinuous nitride layer described above is formed on the surface of the second material, it is desirable to modify (oxidize) it to an oxide equivalent to the second material in step B1 described later.

[0067] In addition, the thickness of the separation membrane described later is determined by the thicknesses of the first sacrificial membrane and the second sacrificial membrane. Therefore, in step A2, the first sacrificial membrane and the second sacrificial membrane are formed until they reach a predetermined thickness corresponding to the desired thickness of the separation membrane. Specifically, for example, in step A2, the first sacrificial membrane and the second sacrificial membrane are formed until they reach a thickness equivalent to the desired thickness of the separation membrane. Note that the thicknesses of the first sacrificial membrane and the second sacrificial membrane are greater than the thickness of the first adsorption inhibition layer.

[0068] As the first raw material, for example, the above-mentioned alkylaminosilane or aminosilane can be used. In addition, as the first raw material, chlorosilanes such as dichlorosilane (SiH2Cl2), tetrachlorosilane (SiCl4), hexachlorodisilane (Si2Cl6), octachlorotrisilane (Si3Cl8), etc. can be used. As the first raw material, one or more of these Si-containing substances can be used.

[0069] As the reactant (nitriding agent), for example, hydrogen nitrides such as ammonia (NH3), diazene (N2H2), hydrazine (N2H4), N3H8, etc. can be used. As the reactant, one or more of these nitrogen (N)-containing substances can be used.

[0070] The processing conditions for supplying the first raw material in step A2 are as follows: Processing temperature: room temperature (25 °C) to 500 °C, preferably room temperature to 400 °C Processing pressure: 1 to 2000 Pa, preferably 1 to 1333 Pa Processing time: 1 to 180 seconds, preferably 10 to 120 seconds First raw material 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 are exemplified.

[0071] The processing conditions for supplying the reactant in step A2 are as follows: Processing pressure: 1 to 4000 Pa, preferably 1 to 1333 Pa Reaction body supply flow rate: 0.01 to 20 slm, preferably 0.01 to 10 slm is exemplified. Other processing conditions can be the same as those at the time of the first raw material supply.

[0072] As shown here, the first sacrificial film and the second sacrificial film are each formed under relatively low-temperature processing conditions. Therefore, the first sacrificial film and the second sacrificial film are composed of nitrides with relatively low density compared to the first material and the third material which are their bases. More specifically, the processing temperature of the first sacrificial film and the second sacrificial film is preferably lower than the processing temperature when the first material and the third material which are the bases are formed.

[0073] Note that by appropriately selecting the first raw material and the reaction body, it is also possible to form a silicon carbonitride film (SiCN film), a silicon carbide film (SiC film), a silicon oxycarbonitride film (SiOCN film), a silicon oxycarbide film (SiOC film), or a silicon oxynitride film (SiON film) as the first sacrificial film and the second sacrificial film. That is, the first sacrificial film and the second sacrificial film can each be a film containing a predetermined element such as Si and at least one of nitrogen and carbon, and can also be a film having a composition different from that of the first material and the third material which are their bases.

[0074] (Step B) Subsequently, the following steps B1 and B2 are performed on the wafer 200 after the first sacrificial film and the second sacrificial film are formed on the surface.

[0075] [Step B1: Embedded film formation] In this step, the following steps (second raw material supply, reaction body supply) are performed on the wafer 200. As the reaction body, for example, an oxidizing agent can be used. In at least one of the steps of the second raw material supply and the reaction body supply, a catalyst can be supplied to the wafer 200. Hereinafter, the case where a catalyst is supplied in both steps of the second raw material supply and the reaction body supply will be described.

[0076] 〔Second raw material supply〕 In this step, valves 243d and 243f are opened to supply the second raw material and the catalyst to the wafer 200. At this time, valves 243g to 243i may be opened to supply an inert gas into the processing chamber 201.

[0077] By performing this step (second raw material supply) under the processing conditions described later, an adsorption layer of the second raw material can be formed in the recesses having the first sacrificial film and the second sacrificial film as side walls, and on at least a part of the upper surfaces of the first sacrificial film and the second sacrificial film respectively. The adsorption layer of the second raw material contains at least a part of the molecular structure of the molecules constituting the second raw material.

[0078] After forming the adsorption layer of the second raw material, valves 243d and 243f are closed to stop the supply of the second raw material and the catalyst to the wafer 200. Then, by the above-described procedure, gaseous substances and the like 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).

[0079] 〔Reactant Supply〕 In this step, valves 243b and 243f are opened to supply the reactant and the catalyst to the wafer 200. At this time, valves 243g to 243i may be opened to supply an inert gas into the processing chamber 201.

[0080] By performing this step (reactant supply) under the processing conditions described later, the adsorption layer of the second raw material formed in the recesses having the first sacrificial film and the second sacrificial film as side walls, and the adsorption layer of the second raw material formed on at least a part of the upper surfaces of the first sacrificial film and the second sacrificial film respectively can be respectively modified. When an oxidizing agent is used as the reactant, the adsorption layer of the second raw material is oxidized, and an oxide layer containing the constituent elements of the second raw material can be formed in the recesses having the first sacrificial film and the second sacrificial film as side walls, and on at least a part of the upper surfaces of the first sacrificial film and the second sacrificial film respectively.

[0081] After modifying the adsorption layer of the second raw material, close valves 243b and 243f and stop supplying the reactant and catalyst to wafer 200. Then, according to the above procedure, remove the gaseous substances remaining in processing chamber 201 from processing chamber 201 and purge processing chamber 201 with an inert gas.

[0082] [Performed a predetermined number of times] Then, a cycle including the second raw material supply and the reactant supply is performed a predetermined number of times (n B times. n B is an integer of 1 or 2 or more). As a result, as shown in FIG. 4(c), an embedded film can be formed in the recess having the first sacrificial film and the second sacrificial film as side walls and at least a part of the upper surfaces of the first sacrificial film and the second sacrificial film. This cycle is executed until the recess is filled with the embedded film. When a Si-containing substance is used as the second raw material and an oxidizing agent is used as the reactant, an oxide film, for example, a silicon oxide film (SiO film), can be formed as the embedded film.

[0083] As the second raw material, for example, Si-containing substances such as the above-mentioned alkylaminosilane, aminosilane, and chlorosilane can be used. As the second raw material, one or more of these can be used.

[0084] As the reactant (oxidizing agent), for example, oxygen (O2), ozone (O3), water vapor (H2O), nitrous oxide (N2O), nitric oxide (NO), nitrogen dioxide (NO2), carbon dioxide (CO2), carbon monoxide (CO), etc. can be used. As the reactant, one or more of these oxygen (O)-containing substances can be used. Here, in order to suppress the first sacrificial film and the second sacrificial film from being substantially modified (oxidized) into an oxide film by the reactant, it is preferable to use a reactant having a relatively weak oxidizing power. For example, a reactant having a weaker oxidizing power than the oxidizing agent used in step E described later can be used. However, when using the first sacrificial film and the second sacrificial film having a composition that is difficult to be oxidized, when it is possible to use a reactant having a strong oxidizing power, a relatively strong oxidizing agent exemplified in step E described later can also be used.

[0085] As the catalyst, for example, pyridine (C5H5N), picoline (C6H7N), lutidine (C7H9N), triethylamine ((C2H5)3N), etc. can be used. As the catalyst, one or more of these amines can be used.

[0086] As the treatment conditions when supplying the second raw material and the catalyst in step B1, 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 raw material 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 are exemplified.

[0087] As the treatment conditions when supplying the reactant and the catalyst in step B1, Treatment pressure: 1 to 4000 Pa, preferably 1 to 1333 Pa 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 are exemplified. Other treatment conditions can be the same as those when supplying the second raw material and the catalyst.

[0088] After the formation of the embedded film on the surface of the wafer 200 is completed, the inside of the processing chamber 201 is purged to remove gases, reaction by-products, etc. remaining in the processing chamber 201 from the processing chamber 201 (after purge). Then, the atmosphere inside the processing chamber 201 is replaced with an inert gas (inert gas replacement), and the pressure inside the processing chamber 201 is restored to normal pressure (atmospheric pressure restoration). Then, the processed wafer 200 is carried out of the reaction tube 203 (boat unloading) and taken out from the boat 217 (wafer discharge). Note that after the boat unloading, the lower end opening of the manifold 209 is sealed by the shutter 219s (shutter close).

[0089] [Step B2: Separation film formation] Subsequently, step B2 is performed on the wafer 200 after wafer discharge, that is, the wafer 200 after the formation of the embedded film on the surface.

[0090] In step B2, among the embedded films formed on the surface of the wafer 200, the portion formed in the concave portion is left as a separation film, and the other portions are removed so that at least a part of the first sacrificial film and the second sacrificial film is exposed. The partial removal of the embedded film can be performed, for example, by anisotropic etching using a plasma-excited etching gas, such as a fluorocarbon (CF) - based gas. The anisotropic etching can be performed, for example, using a first etching unit as a plasma etching apparatus according to known processing procedures and processing conditions. As the CF - based gas, for example, one or more of CF4 gas, C4F6 gas, C4F8 gas, CH2F2 gas, and CHF3 gas can be used. Note that the partial removal of the embedded film is not limited to the case of being performed by anisotropic etching. When the above-described adjacent structure is provided on the flat portion on the surface of the wafer 200, the partial removal of the embedded film can also be performed, for example, by CMP (chemical mechanical polishing).

[0091] By performing step B2, as shown in FIG. 4(d), the surface of the wafer 200 is in a state where the first sacrificial film, the separation film, and the second sacrificial film are exposed adjacent to each other in this order. The first sacrificial film and the second sacrificial film are physically separated (isolated) with the separation film interposed therebetween. When the partial removal of the embedded film is performed by anisotropic etching or CMP as described above, it is possible to make the entire exposed surfaces of the first sacrificial film, the separation film, and the second sacrificial film into smooth surfaces (flat surfaces or curved surfaces) that are adjacent to each other without a step difference.

[0092] As described above, the first sacrificial film and the second sacrificial film are composed of, for example, a nitride such as SiN, and the separation film is composed of, for example, an oxide such as SiO. Also, as described above, the first sacrificial film and the second sacrificial film are each formed under relatively low-temperature processing conditions and are composed of a nitride having a lower density than the first material and the third material which are their substrates. That is, the first sacrificial film and the second sacrificial film are composed of a substance having a composition different from that of the members (separation film, first material, third material) existing around these films, or a substance having the same composition but a lower density, and as will be described later, they exhibit a predetermined etching selectivity with respect to the members existing around them under predetermined etching conditions.

[0093] (Step C: Formation of the first recess and the second recess) Subsequently, step C is performed on the wafer 200 after forming the separation film between the first sacrificial film and the second sacrificial film.

[0094] In step C, the first sacrificial film and the second sacrificial film are selectively removed with respect to the separation membrane, the first material, and the third material. The selective removal of the first sacrificial film and the second sacrificial film can be performed by a known etching method that preferentially (selectively) etches nitrides such as SiN that make up the first sacrificial film and the second sacrificial film over the various substances that make up the separation membrane, the first material, and the third material. Examples of such a method include wet etching using a solution of hot phosphoric acid (H3PO4, 70 to 90 °C) or a hydrofluoric acid solution as an etchant, and dry etching using nitrogen trifluoride (NF3) gas or carbon tetrafluoride (CF4) gas as an etchant. These methods can be performed, for example, using a second etching unit that is an etching apparatus. When the etching resistance of the first sacrificial film to the etchant is lower than the respective etching resistances of the separation membrane and the first material to the etchant, and the etching resistance of the second sacrificial film to the etchant is lower than the respective etching resistances of the separation membrane and the third material to the etchant, the first sacrificial film and the second sacrificial film can be selectively removed with respect to the separation membrane, the first material, and the third material.

[0095] By performing step C, as shown in FIG. 4(e), a first recess having a surface of the first material as a bottom surface with one side surface of the separation membrane as a side wall and a second recess having a surface of the second material as a bottom surface with the other side surface of the separation membrane as a side wall can be formed on the surface of the wafer 200. The first recess and the second recess formed on the surface of the wafer 200, that is, the separation membrane and the like constituting the side surfaces of these recesses can be suitably used as a frame body (a mold for controlling the shape and size of the film formed inside the recess) when forming a film inside the recess in step D1 described later. Further, the first recess and the second recess, that is, the separation membrane constituting the side surfaces of these recesses can also be suitably used as a separator for physically and electrically separating the films formed inside the recesses.

[0096] In step A2, by forming the first sacrificial film so as to protrude beyond the boundary between the surface of the second material and the surface of the first material toward the surface of the second material, in step C, the first recess can be formed so as to protrude beyond the above-described boundary toward the surface of the second material. Further, in step A2, by forming the second sacrificial film so as to protrude beyond the boundary between the surface of the second material and the surface of the third material toward the surface of the second material, in step C, the second recess can be formed so as to protrude beyond the above-described boundary toward the surface of the second material. That is, in this aspect, it is possible to form the first recess and the second recess so that the surfaces of the first material and the third material are not covered by the separation film.

[0097] (Step D) Subsequently, for the wafer 200 after forming the first recess and the second recess on the surface, the following steps D1 and D2 are performed. Step D1 is to perform the above-described transfer procedure (wafer charge and boat load ~ pressure adjustment and temperature adjustment) again, and to transfer the wafer 200 as an intermediate product obtained by performing steps A to C into the processing chamber 201 again, and to start after completing the pressure adjustment and temperature adjustment in the processing chamber 201.

[0098] [Step D1: Dielectric film formation] In this step, the following steps (third raw material supply, reactant supply) are performed on the wafer 200. As the reactant, for example, an oxidizing agent can be used.

[0099] [Third raw material supply] In this step, the valve 243e is opened to supply the third raw material to the wafer 200. At this time, the valves 243g to 243i may be opened to supply an inert gas into the processing chamber 201.

[0100] By performing this step (third raw material supply) under the processing conditions described below, an adsorption layer of the third raw material can be formed in at least a part of the upper surface of the separation film formed on the surface of the wafer 200 and in the first and second recesses formed in the surface of the wafer 200. The adsorption layer of the third raw material contains at least a part of the molecular structure of the molecules constituting the third raw material.

[0101] After forming the adsorption layer of the third raw material, the valve 243e is closed to stop the supply of the third raw material to the wafer 200. Then, by the above-described procedure, gaseous substances and the like remaining in the processing chamber 201 are removed from the processing chamber 201, and the processing chamber 201 is purged with an inert gas (purge).

[0102] 〔Reactant Supply〕 In this step, the valve 243b is opened to supply a reactant to the wafer 200. At this time, the valves 243g to 243i may be opened to supply an inert gas into the processing chamber 201.

[0103] By performing this step (reactant supply) under the processing conditions described below, the adsorption layer of the third raw material formed in the first and second recesses and the adsorption layer of the third raw material formed in at least a part of the upper surface of the separation film formed on the surface of the wafer 200 can be respectively modified. When an oxidant is used as the reactant, the adsorption layer of the third raw material is oxidized, and an oxide layer containing the constituent elements of the third raw material can be formed in at least a part of the upper surface of the separation film formed on the surface of the wafer 200 and in the first and second recesses.

[0104] After modifying the adsorption layer of the third raw material, the valve 243b is closed to stop the supply of the reactant to the wafer 200. Then, by the above-described procedure, gaseous substances and the like remaining in the processing chamber 201 are removed from the processing chamber 201, and the processing chamber 201 is purged with an inert gas.

[0105] 〔Perform a Predetermined Number of Times〕 Then, a cycle including the third raw material supply and the reactant supply is repeated a predetermined number of times (n D times. n D(wherein n is an integer of 1 or more) is performed. As a result, as shown in FIG. 5(a), it is possible to embed the inside of the first concave portion and the second concave portion and form a film covering at least a part of the upper surface of the separation film. This cycle is executed until the inside of the concave portion is filled with the dielectric film. When a metal-containing substance is used as the third raw material and an oxidizing agent is used as the reactant, this film is, for example, an oxide film such as an aluminum oxide film (AlO film), a titanium oxide film (TiO film), a hafnium oxide film (HfO film), a zirconium oxide film (ZrO film), that is, a dielectric film which is a metal oxide film having a higher electron trap density than the SiN film. Note that the dielectric film in the present disclosure is not limited to the oxide film, and a nitride film containing the same metal element can also be applied as the dielectric film. However, when step E described later is further performed, it is preferable to apply an oxide film as the dielectric film.

[0106] As the third raw material, for example, aluminum trichloride (AlCl3), trimethylaluminum (Al(CH3)3), titanium tetrachloride (TiCl4), hafnium tetrafluoride (HfF4), tetrakis(ethylmethylamino)hafnium (Hf[N(CH3)(CH2CH3)]4), zirconium tetrafluoride (ZrF4), tetrakis(ethylmethylamino)zirconium (Zr[N(CH3)Cp]4), etc. can be used. As the third raw material, one or more of these substances, that is, substances containing metal elements such as aluminum (Al), titanium (Ti), hafnium (Hf), zirconium (Zr), etc. (organometals or metal halides) can be used.

[0107] As the reactant (oxidizing agent), one or more of the above-described O-containing substances can be used.

[0108] As the processing conditions when supplying the third raw material in step D1, Processing temperature: room temperature (25°C) to 700°C, preferably 350 to 550°C Processing pressure: 1 to 2000 Pa, preferably 1 to 1333 Pa Processing time: 1 to 180 seconds, preferably 10 to 120 seconds Third raw material 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.

[0109] As the processing conditions when supplying the reactant in Step D1, Processing pressure: 1 to 4000 Pa, preferably 1 to 1333 Pa Reactant supply flow rate: 0.01 to 20 slm, preferably 0.01 to 10 slm is exemplified. Other processing conditions can be the same as those in the case of supplying the third raw material.

[0110] Note that a nitriding agent can also be used as the reactant. As the reactant, one or more of the above-mentioned N-containing substances can be used. When a Si-containing substance is used as the third raw material and a nitriding agent is used as the reactant, a SiN film can be formed as the dielectric film.

[0111] After Step D1 is completed, the above-mentioned transfer procedure (after purge ~ wafer discharge) is carried out again, and the wafer 200 after forming the dielectric film on the surface is taken out from the processing chamber 201 and removed from the boat 217.

[0112] [Step D2: Formation of first dielectric film and second dielectric film] Subsequently, Step D2 is performed on the wafer 200 after wafer discharge, that is, the wafer 200 as an intermediate product after forming the dielectric film on the surface by performing Step D1.

[0113] In step D2, among the dielectric films formed on the surface of the wafer 200, the portions filling the first recess and the second recess are left as the first dielectric film and the second dielectric film, respectively, and the other portions are removed. The partial removal of the dielectric film can be performed by various methods exemplified in step B2, for example, anisotropic etching using a plasma-excited CF-based gas, CMP, or the like. These methods can be performed using, for example, a first etching unit as a plasma etching apparatus.

[0114] By performing step D2, as shown in FIG. 5(b), the surface of the wafer 200 is in a state where the first dielectric film, the separation film, and the second dielectric film are exposed adjacent to each other in this order. The first dielectric film and the second dielectric film are physically and electrically separated (isolated) with the separation film interposed therebetween. When the partial removal of the dielectric film is performed by anisotropic etching or CMP as described above, it is possible to make the entire exposed surfaces of the first dielectric film, the separation film, and the second dielectric film smooth surfaces (flat surfaces or curved surfaces) adjacent to each other without a step. Note that the electron trap density of each of the first dielectric film and the second dielectric film formed of a metal oxide film such as an AlO film is larger than the density of a SiN film having the same film thickness.

[0115] In step C, by forming the first recess so as to protrude to the side of the surface of the second material rather than the boundary between the surface of the second material and the surface of the first material, in step D2, the first dielectric film can be formed so as to protrude to the side of the surface of the second material rather than the above-described boundary. Further, in step C, by forming the second recess so as to protrude to the side of the surface of the second material rather than the boundary between the surface of the second material and the surface of the third material, in step D2, the second dielectric film can be formed so as to protrude to the side of the surface of the second material rather than the above-described boundary.

[0116] (Step E: Formation of First Replacement Oxide Film and Second Replacement Oxide Film) Subsequently, step E is performed on the wafer 200 after forming the first dielectric film and the second dielectric film on the surface. Step E is to re - perform the above - mentioned transfer procedure (wafer charge and boat load ~ pressure adjustment and temperature adjustment), re - transfer the wafer 200 as an intermediate product obtained by performing steps A to D2 into the processing chamber 201, and start after completing the pressure adjustment and temperature adjustment in the processing chamber 201.

[0117] In this step, the valve 243b is opened, and a reactant containing oxygen (i.e., an oxidizing agent) is supplied to the wafer 200. At this time, the valves 243g to 243i may be opened to supply an inert gas into the processing chamber 201.

[0118] By performing step E under the processing conditions described below, through the first dielectric film, a part of the first material in contact with the interface between the first material and the first dielectric film is modified (oxidized) into the first substitution oxide film, and through the second dielectric film, a part of the third material in contact with the interface between the third material and the second dielectric film is modified (oxidized) into the second substitution oxide film. The first substitution oxide film and the second substitution oxide film will be configured as, for example, SiO film or SiON film. In addition, in step E, it is possible to further enhance the characteristics of the separation film, the first dielectric film, and the second dielectric film without impairing their characteristics as oxide films. For example, it is possible to re - oxidize (post - oxidize) the separation film, the first dielectric film, and the second dielectric film, desorb impurities from these films, densify these films, and enhance the insulation property.

[0119] After completing the above - mentioned modification, the valve 243b is closed to stop the supply of the oxidizing agent into the processing chamber 201. Then, according to the above - mentioned procedure, the gaseous substances remaining in the processing chamber 201 are exhausted from the processing chamber 201, and the processing chamber 201 is purged with an inert gas.

[0120] As the oxidizing agent, for example, ozone (O3), O2 + hydrogen (H2), O2 + deuterium (D2), O3 + H2, O3 + D2, hydrogen peroxide (H2O2), oxygen-containing substances such as O2 or O3 excited to a plasma state can be used. As the oxidizing agent, one or more of these can be used. Here, the co-listing of two substances such as "O2 + H2" means a mixture of O2 and H2. When supplying the mixture, the two substances may be mixed (premixed) in the supply pipe and then supplied into the processing chamber 201, or the two substances may be separately supplied into the processing chamber 201 from different supply pipes and mixed (postmixed) in the processing chamber 201. In addition, when it is possible to form the first substitution oxide film and the second substitution oxide film through the first dielectric film and the second dielectric film by adjusting the processing conditions and the like, an oxidizing agent with a relatively weak oxidizing power exemplified in step B described above can also be used.

[0121] As the processing conditions when supplying the oxidizing agent in step E, Processing temperature: 350 to 1000 °C, preferably 400 to 650 °C Processing pressure: 1 to 105000 Pa, preferably 10 to 10000 Pa Processing time: 1 to 10000 seconds, preferably 5 to 3600 seconds Oxidizing agent 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 are exemplified.

[0122] (Step F: Formation of tunnel oxide film and channel film) Subsequently, step F is performed on the wafer 200 after the first substitution oxide film and the second substitution oxide film are formed.

[0123] In this step, a tunnel oxide film and a channel film are sequentially laminated on the surfaces of the isolation film, the first dielectric film, and the second dielectric film formed on the wafer 200. The formation of the tunnel oxide film and the channel film can be performed by known methods, each of which is known as a part of the manufacturing process of a memory cell in a flash memory. Note that step F may be performed in-situ in the above-described processing chamber 201 where step E is performed, or may be performed ex-situ in the processing chamber of another substrate processing apparatus.

[0124] Through the above steps A to F, the laminated structure shown in FIG. 5(d) is manufactured.

[0125] This laminated structure can be suitably used, for example, as a part of the components of a memory cell of a flash memory. That is, the first dielectric film and the second dielectric film formed by the above-described method are configured as metal oxide films and have a higher electron trap density than a SiN film, and are precisely formed with high dimensional accuracy so as to have an appropriate shape. Therefore, they can be suitably used as the charge trap layers of the memory cell, respectively. In addition, since the isolation film is made of an oxide film such as a SiO film, it can be suitably used as an isolation layer for insulating between adjacent charge trap layers in the memory cell of the flash memory. Further, since the first substitution oxide film and the second substitution oxide film are made of an oxide film (SiO film or SiON film), they can be suitably used as blocking layers for suppressing carrier leakage from the charge trap layer, respectively.

[0126] (3) Effects of this embodiment According to this embodiment, one or more of the following effects can be obtained.

[0127] (a) By performing the above steps A to C, in a substrate having a structure in which the surfaces of the first to third materials are adjacent to each other in this order, it is possible to selectively form recesses (first recess, second recess) on the surface of the base formed of a specific material (first material, third material). These formed recesses can be suitably used, for example, as a frame (mold) when forming a film inside them, or as a separator that physically and electrically separates the films formed inside them. Thereby, it becomes possible to precisely form a film on the substrate. Further, if these recesses are used as a frame and a dielectric film is formed inside each of them, for example, these films formed in the recesses can be suitably used as a charge trap layer of a memory cell included in a flash memory.

[0128] (b) When the second material is an oxide and the first material and the third material are each at least one of an oxide or a non-oxide having a smaller oxygen content ratio than the second material, the above-described effects can be obtained more reliably. For example, when the first material and the third material are each a nitride such as SiN and the second material is an oxide such as SiO, by utilizing the OH termination (hydroxyl group termination) selectively formed on the surface of the second material which is an oxide, it becomes possible to selectively form the first sacrificial film and the second sacrificial film on the surfaces of the first material and the third material, respectively. Further, when the first material to the third material are the above-described materials, a structure in which they are adjacent to each other in this order can be suitably used, for example, as a part of the components of a memory cell of a flash memory.

[0129] (c) When the separation film is an oxide film such as a SiO film, the above-described effects can be obtained more reliably. Further, when the separation film is an oxide film such as a SiO film, this film can be suitably used, for example, as a separation layer that insulates between adjacent charge trap layers in a memory cell of a flash memory.

[0130] (d) In step A, by performing the above-described steps A1 and A2, each of the first sacrificial film and the second sacrificial film can be efficiently and selectively formed on the surface of the second material. As a result, in step C to be performed thereafter, each of the first recess and the second recess can be efficiently formed with high dimensional accuracy.

[0131] (e) In step A, by forming the first sacrificial film so as to protrude to the side of the surface of the second material rather than the boundary between the surface of the second material and the surface of the first material, and by forming the second sacrificial film so as to protrude to the side of the surface of the second material rather than the boundary between the surface of the second material and the surface of the third material, the shape and size of each of the first recess and the second recess formed in step C can be appropriately adjusted. For example, by forming the first sacrificial film and the second sacrificial film as described above in step A, the surfaces of the first material and the third material can be covered with the separation film without being covered, and the first recess and the second recess can be formed. Thereby, the shape and size of each of the first dielectric film formed in the first recess and the second dielectric film formed in the second recess in step D can be made into a shape and size suitable for using these films as the charge trap layer of the memory cell.

[0132] (f) When performing the above-described steps B1 and B2 in step B, by forming the separation film using the recess having the first sacrificial film and the second sacrificial film as side walls as a frame, the separation film can be formed with good controllability and high dimensional accuracy. Further, by covering at least a part of the upper surface of each of the first sacrificial film and the second sacrificial film with an embedding film in step B1 and removing the unnecessary part of the embedding film in step B2, the separation film can be made into a film without voids or the like that fills the inside of the recess without a gap. By these, the separation film can be suitably used, for example, as a separation layer that insulates between adjacent charge trap layers.

[0133] Note that by forming the embedded film with an oxide film such as an SiO film, the film obtained by processing this film can be suitably used, for example, as a separation film for a charge trap layer.

[0134] Also, in step B1, by performing a cycle including the second raw material supply and the reactant supply a predetermined number of times, it becomes possible to form the embedded film with good step coverage and good controllability. As a result, the quality of the separation film can be improved, and the film obtained by processing this film can be suitably used, for example, as a separation film for a charge trap layer.

[0135] (g) In step D, by forming a first dielectric film in the first recess and a second dielectric film in the second recess, respectively, each of the first recess and the second recess can function as a frame (mold) when forming the first dielectric film and the second dielectric film. As a result, the shape and dimensions of each of the obtained first dielectric film and second dielectric film can be made, for example, a shape and dimensions suitable for the charge trap layer of a memory cell. Further, a structure can be formed in which a separation film as a separator for separating these films is disposed between the first dielectric film and the second dielectric film. Thereby, for example, when the first dielectric film and the second dielectric film are applied as the charge trap layer of a memory cell, it becomes possible to suppress the electrical interference between the charge trap layers by the separation film.

[0136] Note that since each of the first dielectric film and the second dielectric film has an electron trap density larger than that of a silicon nitride film, these films can be suitably used, for example, as a charge trap layer of a memory cell.

[0137] (h) In step D, by forming the first dielectric film and the second dielectric film according to the procedures of steps D1 and D2, it becomes possible to fill the inside of the first recess without gaps with the first dielectric film and to fill the inside of the second recess without gaps with the second dielectric film, respectively. As a result, these films can be suitably used, for example, as a charge trap layer of a memory cell.

[0138] (i) Since each of the first dielectric film and the second dielectric film is an oxide film such as a metal oxide film, each of the first dielectric film and the second dielectric film can be suitably used, for example, as a charge trap layer of a memory cell.

[0139] Also, since each of the first dielectric film and the second dielectric film is an oxide film such as a metal oxide film, when forming the first substitution oxide film or the second substitution oxide film in step E, even if oxidation (modification) is performed on a part of the first material or a part of the third material through the first dielectric film or the second dielectric film, the characteristics of these films as oxide films can be maintained as they are. On the other hand, for example, when the first dielectric film or the second dielectric film is a nitride film, when oxidation is performed on a part of the first material or a part of the third material through the first dielectric film or the second dielectric film, at least a part of the nitrogen in the film will desorb, and it may become difficult to maintain the characteristics of these films as nitride films.

[0140] (j) After step D, by performing step E of supplying an oxidizing agent to the wafer 200, it becomes possible to form the first substitution oxide film and the second substitution oxide film as oxide films having high insulation properties adjacent to the first dielectric film and the second dielectric film. Also, by performing modification (oxidation) through the first dielectric film and the second dielectric film, the film quality of the first dielectric film and the second dielectric film can be improved, and these films can be made into more suitable films, for example, as a charge trap layer of a memory cell.

[0141] (k) If the first dielectric film and the second dielectric film formed by the method of the present disclosure are used as films constituting the charge trapping layer of a memory cell, for example, it is possible to improve the performance of a flash memory device.

[0142] (l) Since the etching resistance of the first sacrificial film with respect to the etchant used in step C is lower than the etching resistance of the first material with respect to the etchant, and the etching resistance of the second sacrificial film with respect to the etchant is lower than the etching resistance of the third material with respect to the etchant, in step C, etching of the surfaces of the first material and the third material can be suppressed, and each of the first recess and the second recess can be formed with good controllability and high dimensional accuracy.

[0143] Note that since the first sacrificial film and the second sacrificial film are each composed of a film containing a predetermined element such as Si and at least one of nitrogen and carbon, the etching resistance of these films can be appropriately reduced, and the above-described effects can be effectively obtained.

[0144] (m) The above-described effects can be similarly obtained even when a predetermined substance is arbitrarily selected and used from the above-described various modifiers, various first to third raw materials, various reactants (oxidizing agents, nitriding agents), and various inert gases.

[0145] <Other aspects of the present disclosure> The aspects of the present disclosure have been specifically described above. However, the present disclosure is not limited to the above-described aspects, and various modifications can be made without departing from the gist thereof.

[0146] For example, after performing step A2 (formation of the first sacrificial film and the second sacrificial film), before starting step B1 (formation of the embedded film), an oxidizing agent such as water vapor (H2O) or oxygen (O2) may be supplied to the wafer 200 in the processing chamber 201. The processing procedure and processing conditions in this case can be the same as those in the reactant supply of step B1, for example. Also, after performing step A2 and before starting step B1, the wafer 200 may be taken out of the processing chamber 201 and exposed to the atmosphere.

[0147] Even in these cases, the same effects as those of the above-described embodiments can be obtained. Also, when done in these ways, it becomes possible to remove and / or invalidate the first adsorption inhibition layer remaining on the surface of the wafer 200 before starting step B, and in step B1 performed thereafter, it becomes possible to form the embedded film efficiently and with good quality.

[0148] Also, for example, in step D, after forming the first concave portion and the second concave portion on the surface of the wafer 200, (d-1) Step D1' of selectively forming a second adsorption inhibition layer (second inhibitor layer) that inhibits the adsorption of the third source gas on the surfaces of the first material and the third material on the surface of the separation film; (d-2) Step D2' of forming a first dielectric film on the surface of the first material and a second dielectric film on the surface of the third material by supplying the third source gas to the wafer 200; may be performed.

[0149] The processing procedure and processing conditions in step D1' can be the same as those in step A1 (formation of the first adsorption inhibition layer) described above, for example. The processing procedure and processing conditions in step D2' can be the same as those in step D1 (formation of the dielectric film) described above, for example.

[0150] Even in this case, the same effects as those in the above-described embodiment can be obtained. Further, in such a case, each of the first dielectric film and the second dielectric film can be efficiently formed selectively with respect to the surface of the separation film. Further, after the formation of the first dielectric film and the second dielectric film, the implementation of step D2 for removing unnecessary dielectric films can be omitted, and the productivity of the device can be improved.

[0151] Note that in step D, when performing steps D1' and D2', it is preferable that step D2' be performed until the inside of the first recess is filled with the first dielectric film and the inside of the second recess is filled with the second dielectric film, respectively. By filling the inside of the first recess without a gap with the first dielectric film and filling the inside of the second recess without a gap with the second dielectric film, each of the first dielectric film and the second dielectric film can be suitably used, for example, as a charge trap layer of a memory cell.

[0152] Also, for example, in the above-described embodiment, an example in which an O-containing substance exemplified as the reactant in step B1 (oxidizing agent) is used as the reactant used in step D1 has been described. The present disclosure is not limited to this, and as the reactant used in step D1, a relatively strongly oxidizing O-containing substance exemplified as the oxidizing agent in step E1 can be used. In this case, in step D1, parallel to the formation of the dielectric film, the first material and the third material can be modified (oxidized) to form a first substitution oxide film and a second substitution oxide film. That is, step E1 can be omitted, or the processing time required for step E can be shortened. However, when steps D1 and E1 are performed as separate steps as in the above-described embodiment, in step E1, it is possible to control the adjustment of the thicknesses of the first substitution oxide film and the second substitution oxide film with good controllability.

[0153] The recipes used for each process are preferably prepared individually according to the process content, recorded and stored in the storage device 121c via a telecommunication line or an external storage device 123. When starting each process, it is preferable that the CPU 121a appropriately selects an appropriate recipe according to the process content from among a plurality of recipes recorded and stored in the storage device 121c. As a result, films with various film types, composition ratios, film qualities, and film thicknesses can be formed with good reproducibility by the processing device. In addition, the burden on the operator can be reduced, operation mistakes can be avoided, and each process can be started quickly.

[0154] The above-mentioned recipes are not limited to newly created ones. For example, they may be prepared by modifying existing recipes already installed in the processing device. When modifying a recipe, the modified recipe may be installed in the processing device via a telecommunication line or a recording medium on which the recipe is recorded. Alternatively, the input / output device 122 provided in the existing processing device may be operated to directly modify the existing recipe already installed in the processing device.

[0155] In the above aspect, an example of performing a film-forming process using a batch-type processing device that processes a plurality of substrates at once has been described. The present disclosure is not limited to the above aspect, and can be suitably applied, for example, also when performing a film-forming process using a single-wafer-type processing device that processes one or several substrates at once. Further, in the above aspect, an example of performing a film-forming process using a processing device having a hot-wall type processing furnace has been described. The present disclosure is not limited to the above aspect, and can be suitably applied also when performing a film-forming process using a processing device having a cold-wall type processing furnace.

[0156] Also, in the above-described aspect, a series of processing sequences leading to steps A1, A2, and B1 are continuously performed (in-situ) in the same processing chamber of the same processing apparatus, and further, an example in which steps D1 and E are performed in the same processing chamber of the same processing apparatus has been described. The present disclosure is not limited to the above-described aspect. Any one of steps A1, A2, B1, D1, and E 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, respectively.

[0157] Even when using these processing apparatuses, each process can be performed under the same processing procedures and processing conditions as those in the above-described aspect and modified examples, and the same effects as those in the above-described aspect and modified examples can be obtained.

[0158] The above-described aspects and modified examples can be used in appropriate combinations. At this time, the processing procedures and processing conditions can be, for example, the same as those in the above-described aspects and modified examples.

Description of Reference Numerals

[0159] 200 wafers (substrates)

Claims

1. (a) In a substrate having a structure in which the surfaces of a first material, a second material, and a third material are adjacent to each other in this order, forming a first sacrificial film on the surface of the first material and a second sacrificial film on the surface of the third material, respectively, selectively with respect to the surface of the second material; (b) forming a separation film in a recess having the first sacrificial film and the second sacrificial film as side walls; (c) selectively removing the first sacrificial film and the second sacrificial film with respect to the separation film, the first material, and the third material, thereby forming a first recess having the surface of the first material as a bottom surface with one side surface of the separation film as a side wall, and a second recess having the surface of the second material as a bottom surface with the other side surface of the separation film as a side wall; A substrate processing method comprising the steps of.

2. The substrate processing method according to claim 1, wherein the second material is an oxide, and the first material and the third material are each at least one of an oxide having a smaller oxygen content ratio than the second material or a non-oxide.

3. The substrate processing method according to claim 1, wherein the first material and the third material are each a nitride, and the second material is an oxide.

4. The substrate processing method according to claim 1, wherein the first material and the third material are each silicon nitride, and the second material is silicon oxide.

5. The substrate processing method according to any one of claims 2 to 4, wherein the separation film is an oxide film.

6. The substrate processing method according to any one of claims 2 to 4, wherein the separation film is a silicon oxide film.

7. (a) includes (a-1) selectively forming a first adsorption inhibition layer that inhibits the adsorption of a first raw material on the surface of the second material with respect to the surfaces of the first material and the third material; (a-2) forming the first sacrificial film on the surface of the first material and the second sacrificial film on the surface of the third material, respectively, by supplying the first raw material to the substrate; The substrate processing method according to claim 1.

8. In (a), the first sacrificial film is formed so as to protrude to the side of the surface of the second material rather than the boundary between the surface of the second material and the surface of the first material, according to the substrate processing method of claim 1.

9. (b) includes (b-1) forming an embedding film that fills the inside of the recess and covers at least a part of the upper surfaces of the first sacrificial film and the second sacrificial film; (b-2) Among the embedded films, a step of leaving a portion formed in the concave portion as the separation film and removing other portions; The substrate processing method according to claim 1, comprising:

10. (d) A step of forming a first dielectric film in the first concave portion and a second dielectric film in the second concave portion, respectively, in the substrate processing method according to claim 1.

11. (d) is (d-1) A step of embedding the first concave portion and the second concave portion and forming a dielectric film covering at least a part of the upper surface of the separation film; (d-2) Among the dielectric films, a step of leaving portions embedding the first concave portion and the second concave portion as the first dielectric film and the second dielectric film, respectively, and removing other portions; The substrate processing method according to claim 10, comprising:

12. (d) is (d-1) A step of selectively forming a second adsorption inhibition layer that inhibits adsorption of the third raw material on the surface of the separation film with respect to the surfaces of the first material and the third material; (d-2) A step of forming the first dielectric film on the surface of the first material and the second dielectric film on the surface of the third material, respectively, by supplying the third raw material to the substrate; The substrate processing method according to claim 10, comprising:

13. The substrate processing method according to claim 10, wherein the first dielectric film and the second dielectric film are each an oxide film.

14. (e) After (d), a step of supplying an oxidizing agent to the substrate to modify a part of the first material in contact with the interface between the first material and the first dielectric film through the first dielectric film into a first substitution oxide film, in the substrate processing method according to claim 13.

15. The substrate processing method according to claim 10, wherein the first dielectric film and the second dielectric film are each a film constituting a charge trap layer of a memory cell.

16. The etching resistance of the first sacrificial film with respect to the etching agent used in (c) is lower than the etching resistance of the first material with respect to the etching agent, and the etching resistance of the second sacrificial film with respect to the etching agent is lower than the etching resistance of the third material with respect to the etching agent, in the substrate processing method according to claim 1.

17. In a substrate having a structure in which the surfaces of a first material, a second material, and a third material are adjacent to each other in that order, a step of selectively forming a first sacrificial film on the surface of the first material and a second sacrificial film on the surface of the third material with respect to the surface of the second material, respectively. A step of forming a separation film in a recess having the first sacrificial film and the second sacrificial film as side walls. A step of selectively removing the first sacrificial film and the second sacrificial film with respect to the separation film, the first material, and the third material, thereby forming a first recess having the surface of the first material as a bottom surface with one side surface of the separation film as a side wall and a second recess having the surface of the second material as a bottom surface with the other side surface of the separation film as a side wall. A method of manufacturing a semiconductor device having the above steps.

18. In a substrate having a structure in which the surfaces of a first material, a second material, and a third material are adjacent to each other in that order, a procedure of selectively forming a first sacrificial film on the surface of the first material and a second sacrificial film on the surface of the third material with respect to the surface of the second material, respectively. A procedure of forming a separation film in a recess having the first sacrificial film and the second sacrificial film as side walls. A procedure of selectively removing the first sacrificial film and the second sacrificial film with respect to the separation film, the first material, and the third material, thereby forming a first recess having the surface of the first material as a bottom surface with one side surface of the separation film as a side wall and a second recess having the surface of the second material as a bottom surface with the other side surface of the separation film as a side wall. A program for causing a computer to execute the above procedures on a substrate processing apparatus.

19. A program for causing a computer to execute a procedure of forming a first sacrificial film on the surface of the first material and a second sacrificial film on the surface of the third material by supplying a first raw material to the substrate, respectively, on a substrate processing apparatus used in the substrate processing method according to claim 1.

20. A substrate processing apparatus used in the substrate processing method according to claim 1, A first raw material supply system configured to supply a first raw material to the substrate, A control unit configured to be able to control the first raw material supply system so as to execute a process of forming a first sacrificial film on the surface of the first material and a second sacrificial film on the surface of the third material by supplying the first raw material to the substrate. A substrate processing apparatus comprising the above components.

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