Semiconductor element forming method

Abstract

A semiconductor element forming method includes: a step (S10) of forming a first coating film (Ps1) covering a recess (R) provided in a laminated structure (L) supported by a base material (S); a step (S20) for forming a second coating film (Ps2) for selectively covering, from the first coating film (Ps1), a portion of the recess (R) in which the first coating film (Ps1) is formed, said portion being located on the front surface side; and a step (S31) for etching a groove deep part (Rf) using the first chemical solution (C1) in order to enlarge the width of the groove deep part (Rf), which is the part of the groove (R) not covered by the second coating film (Ps2).

Description

Technical Field

[0001] The present invention relates to a method for forming a semiconductor element. Background Art

[0002] The method for forming a semiconductor device described in Patent Document 1 includes: a step of forming a coating layer; and a step of performing etching. In the step of forming the coating layer, a coating layer is formed that selectively coats a portion on the surface side of a recess in a stacked structure supported by a substrate. In the step of performing etching, the deep part in the recess is etched with a chemical solution in such a way as to expand the diameter of the deep part deeper than the coating layer.

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2021-34691 Summary of the Invention

[0006] [Problems to be Solved by the Invention]

[0007] In the method for forming a semiconductor device described in Patent Document 1, a stacked structure is formed by alternately stacking layers of different materials. Therefore, it is necessary to simultaneously form a coating layer on the layers of different materials.

[0008] The inventors of the present application focused on the adsorption sites for adsorbing molecules of the material for the coating layer in each layer of different materials and repeatedly conducted intensive research. As a result, it was found that there is a case where the number of adsorption sites for adsorbing molecules of the material for the coating layer in a layer of a certain material is less than the number of adsorption sites in a layer of another material. As a result, the inventors of the present application speculated that in the layer with a smaller number of adsorption sites, the non-adsorption region where the molecules of the material for the coating layer are not adsorbed may increase. And the inventors of the present application speculated that if the non-adsorption region in the coating layer increases, the chemical solution may etch the layer in the portion of the recess in the substrate where the diameter does not need to be expanded. "Diameter" is an example of "width".

[0009] The present invention has been completed in view of the above problems, and an object thereof is to provide a method for forming a semiconductor element that can suppress the chemical solution from etching a portion of the recess in the substrate where the width does not need to be expanded.

[0010] [Technical Means for Solving the Problems]

[0011] According to one aspect of the present invention, a method of forming a semiconductor device includes: a step of forming a first coating film that coats a groove of a stacked structure supported by a substrate; a step of forming a second coating film that selectively coats a surface-side portion of the groove having the first coating film formed thereon from the first coating film; and a step of etching the deep portion of the groove with a first chemical solution to widen the width of the deep portion of the groove that is not covered by the second coating film in the groove.

[0012] In one embodiment, it further includes: a step of removing the second coating film after the step of etching with the first chemical solution; and a step of removing the first coating film after the step of removing the second coating film.

[0013] In one embodiment, in the step of removing the first coating film, the first coating film is removed with a second chemical solution, and the deep portion of the groove is etched with the second chemical solution.

[0014] In one embodiment, in the step of forming the first coating film, the first coating film is formed by ALD (Atomic Layer Deposition), ozone water, hydrogen peroxide water, or a mixed solution of sulfuric acid and hydrogen peroxide water.

[0015] In one embodiment, the number of adsorption sites per unit area of the material for adsorbing the second coating film on the surface of the first coating film is greater than the number of adsorption sites per unit area of a specific layer in different layers constituting the stacked structure. The specific layer represents the layer having the smallest number of adsorption sites per unit area among the different layers constituting the stacked structure.

[0016] In one embodiment, the adsorption sites include hydroxyl groups.

[0017] In one embodiment, the step of forming the second coating film includes: a step of forming a partial filling layer that partially fills the deep portion of the groove from the first coating film; a step of supplying a water repellent after forming the partial filling layer; and a step of removing the partial filling layer and the water repellent after forming the second coating film on the surface side of the groove from the first coating film by supplying the water repellent.

[0018] In one embodiment, the step of forming the partial filling layer includes: a step of forming a filling layer that fills the groove from the first coating film; and a step of partially removing the filling layer after forming the filling layer.

[0019] [Effects of the Invention]

[0020] According to the present invention, it is possible to suppress the etching of the portions in the grooves of the substrate that do not require width expansion by the liquid medicine. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a schematic view of the substrate processing apparatus of the present embodiment.

[0022] Figure 2 is a schematic view of the substrate processing apparatus of the present embodiment.

[0023] Figure 3 is a block diagram of the substrate processing apparatus of the present embodiment.

[0024] Figure 4 FIG. (a) is a schematic side view of a semiconductor element manufactured using the substrate processing apparatus of the present embodiment, (b) is a schematic top view of the semiconductor element, and (c) is a partial enlarged view of (b).

[0025] Figure 5 FIGS. (a) to (e) are schematic views for explaining the method of forming a semiconductor element of the present embodiment.

[0026] Figure 6 FIGS. (a) to (g) are schematic views for explaining the method of forming a semiconductor element of a comparative example.

[0027] Figure 7 FIGS. (a) to (c) are schematic views for explaining the state of the surface of the insulating layer of the stacked structure of the substrate of a comparative example.

[0028] Figure 8 FIGS. (a) to (c) are schematic views for explaining the state of the surface of the sacrificial layer of the stacked structure of the substrate of a comparative example.

[0029] Figure 9 FIGS. (a) and (b) are schematic views for explaining the method of forming a semiconductor element of the present embodiment.

[0030] Figure 10 FIGS. (a) and (b) are schematic views for explaining the method of forming a semiconductor element of the present embodiment.

[0031] Figure 11 FIGS. (a) and (b) are schematic views for explaining the method of forming a semiconductor element of the present embodiment.

[0032] Figure 12 FIGS. (a) and (b) are schematic views for explaining the method of forming a semiconductor element of the present embodiment.

[0033] Figure 13(a) and (b) are schematic diagrams for explaining the method of forming a semiconductor element according to the present embodiment.

[0034] Figure 14 (a) to (c) are schematic diagrams for explaining the state of the surface of the first coating film according to the present embodiment.

[0035] Figure 15 is a flowchart of the method of forming a semiconductor element according to the present embodiment.

[0036] Figure 16 is a flowchart of the method of forming a semiconductor element according to the present embodiment.

[0037] Figure 17 is a schematic diagram of the substrate processing apparatus according to the present embodiment.

[0038] Figure 18 is a schematic diagram of a semiconductor element formed by the method of forming a semiconductor element according to the present embodiment. Detailed Embodiment

[0039] Hereinafter, an embodiment of the method of forming a semiconductor element of the present invention will be described with reference to the accompanying drawings. Further, in the drawings, the same or corresponding parts are denoted by the same reference numerals, and redundant description will not be repeated. Further, in the present specification, in order to easily understand the invention, the X-axis, Y-axis, and Z-axis that are orthogonal to each other may be described. Typically, the X-axis and Y-axis are parallel to the horizontal direction, and the Z-axis is parallel to the vertical direction. In addition, in the present specification, in order to easily understand the invention, the x-axis, y-axis, and z-axis that are orthogonal to each other may be described. Typically, the x-axis and y-axis extend parallel to the main surface of the substrate or base material, and the z-axis extends in a direction perpendicular to the main surface of the substrate or base material.

[0040] First, with reference to Figure 1 , an embodiment of the substrate processing apparatus 100 of the present invention will be described. Figure 1 is a schematic top view of the substrate processing apparatus 100 according to the present embodiment.

[0041] The substrate processing apparatus 100 processes a substrate W. The substrate processing apparatus 100 processes the substrate W in such a manner as to perform at least one of etching, surface treatment, property imparting, processing film formation, removal, and cleaning of at least a part of the film on the substrate W.

[0042] The substrate W is used as a semiconductor substrate. The substrate W includes a semiconductor wafer. For example, the substrate W is substantially circular plate-shaped. Here, the substrate processing apparatus 100 processes the substrate W one by one.

[0043] As Figure 1As shown, the substrate processing apparatus 100 includes a plurality of chambers 110, a fluid cabinet 100A, a fluid tank 100B, a plurality of load ports LP, an index robot IR, a central robot CR, and a control device 101. The control device 101 controls the load ports LP, the index robot IR, and the central robot CR.

[0044] Each load port LP stacks and houses a plurality of substrates W. The index robot IR transports the substrate W between the load port LP and the central robot CR. The central robot CR transports the substrate W between the index robot IR and the chamber 110. The chamber 110 sprays a liquid onto the substrate W respectively to process the substrate W. The liquid includes a processing liquid, a removing liquid, a water repellent, and / or a chemical solution. The fluid cabinet 100A houses the liquid. Furthermore, the fluid cabinet 100A may also house a gas.

[0045] Specifically, the plurality of chambers 110 form a plurality of towers TW ( Figure 1 four towers TW in this case) arranged in a manner that surrounds the central robot CR in a top view. Each tower TW includes a plurality of chambers 110 stacked vertically ( Figure 1 three chambers 110 in this case). The fluid tank 100B corresponds to the plurality of towers TW respectively. The liquid in the fluid cabinet 100A is supplied to all the chambers 110 included in the tower TW corresponding to the fluid tank 100B through any one of the fluid tanks 100B. In addition, the gas in the fluid cabinet 100A is supplied to all the chambers 110 included in the tower TW corresponding to the fluid tank 100B through any one of the fluid tanks 100B.

[0046] The control device 101 controls various operations of the substrate processing apparatus 100. The control device 101 includes a control unit 102 and a storage unit 104.

[0047] The control unit 102 has a processor. The control unit 102 has, for example, a Central Processing Unit (CPU). Alternatively, the control unit 102 may have a general-purpose arithmetic unit.

[0048] The storage unit 104 stores data and computer programs. The data includes recipe data. The recipe data includes information representing a plurality of recipes. Each of the plurality of recipes specifies the processing content and processing sequence of the substrate W.

[0049] The storage unit 104 includes a main storage device and an auxiliary storage device. The main storage device is, for example, a semiconductor memory. The auxiliary storage device is, for example, a semiconductor memory and / or a hard disk drive. The storage unit 104 may also include a removable medium. The storage unit 104 is equivalent to an example of a non-transitory computer-readable storage medium. The control unit 102 executes the computer program stored in the storage unit 104 to perform substrate processing operations.

[0050] Next, with reference to Figure 2 , the substrate processing apparatus 100 of the present embodiment will be described. Figure 2 FIG. Figure 2 is a schematic view of the substrate processing apparatus 100.

[0051] The substrate processing apparatus 100 includes a chamber 110, a substrate holding unit 120, and a liquid supply unit 130. The chamber 110 houses the substrate W. The substrate holding unit 120 holds the substrate W.

[0052] The chamber 110 has a substantially box shape with an internal space. The chamber 110 houses the substrate W. Here, the substrate processing apparatus 100 is a single wafer type that processes the substrate W one by one, and the substrate W is housed one by one in the chamber 110. The substrate W is housed in the chamber 110 and is processed in the chamber 110. At least a part of each of the substrate holding unit 120 and the liquid supply unit 130 is housed in the chamber 110.

[0053] The substrate holding unit 120 holds the substrate W. The substrate holding unit 120 horizontally holds the substrate W such that the upper surface (front surface) Wa of the substrate W faces upward and the back surface (lower surface) Wb of the substrate W faces vertically downward. In addition, the substrate holding unit 120 rotates the substrate W while holding the substrate W. A stacked structure having grooves is provided on the upper surface Wa of the substrate W, and details will be described later. The groove means a recess formed in the substrate W. For example, the groove is a hole or a groove formed in the substrate W. The hole is, for example, a memory hole.

[0054] For example, the substrate holding unit 120 may also be a clamping type that clamps the end portion of the substrate W. Alternatively, the substrate holding unit 120 may have any mechanism for holding the substrate W from the back surface Wb. For example, the substrate holding unit 120 may also be a vacuum type. In this case, the substrate holding unit 120 horizontally holds the substrate W by adsorbing the central portion of the back surface Wb of the substrate W, which is a non-device formation surface, to the upper surface. Alternatively, the substrate holding unit 120 may combine a clamping type in which a plurality of chuck pins are brought into contact with the peripheral end surface of the substrate W and a vacuum type.

[0055] For example, the substrate holding unit 120 includes a rotating base 121, a chuck member 122, a shaft 123, an electric motor 124, and a housing 125. The chuck member 122 is provided on the rotating base 121. The chuck member 122 clamps the substrate W. Typically, a plurality of chuck members 122 are provided on the rotating base 121.

[0056] The shaft 123 is a hollow shaft. The shaft 123 extends in the vertical direction along the rotation axis Ax. The rotating base 121 is coupled to the upper end of the shaft 123. The substrate W is placed above the rotating base 121.

[0057] The rotating base 121 is in the shape of a circular plate and horizontally supports the substrate W. The shaft 123 extends downward from the central portion of the rotating base 121. The electric motor 124 imparts a rotational force to the shaft 123. The electric motor 124 rotates the substrate W and the rotating base 121 about the rotation axis Ax by rotating the shaft 123 in the rotational direction. The housing 125 encloses the shaft 123 and the electric motor 124.

[0058] The liquid supply unit 130 supplies liquid to the substrate W. Typically, the liquid supply unit 130 supplies liquid to the upper surface Wa of the substrate W.

[0059] The liquid supply unit 130 includes a processing liquid supply unit 132, a removal liquid supply unit 134, a water repellent supply unit 136, and a chemical liquid supply unit 138. At least a part of the processing liquid supply unit 132, the removal liquid supply unit 134, the water repellent supply unit 136, and the chemical liquid supply unit 138 is housed in the chamber 110.

[0060] The processing liquid supply unit 132 supplies a processing liquid to the upper surface Wa of the substrate W. For example, the processing liquid contains a solute and a volatile solvent. After the processing liquid is supplied to the upper surface Wa of the substrate W, the solvent volatilizes, and thus a filling layer is formed from the solute. The filling layer is a solid film containing the solute component. The filling layer can hold the particles remaining in the grooves of the substrate W. When the filling layer is formed, the particles attached to the upper surface Wa of the substrate W are detached from the substrate W and held in the filling layer.

[0061] Here, "curing", for example, means that the solute solidifies due to forces acting between molecules or atoms, etc., along with the volatilization of the solvent. "Hardening", for example, means that the solute solidifies through chemical changes such as polymerization or crosslinking. Therefore, "curing or hardening" means that the solute "solidifies" for various reasons. Furthermore, the processing liquid only needs to cure or harden to the extent that it can hold the particles, and it is not necessary for the solvent to completely volatilize. In addition, the "solute component" forming the filling layer may be the solute itself contained in the processing liquid, or a component derived from the solute, for example, a component obtained as a result of a chemical change.

[0062] As the solute, various resins can be used. These resins are soluble in any solvent and can form a filling layer in a state where the particles attached to the upper surface of the substrate W are detached from the substrate W and held when cured or hardened. For example, as the solute, a resin having the property of being hardly soluble or insoluble in water before being heated to a specified modification temperature or higher and being modified to be water-soluble by heating to a temperature equal to or higher than the modification temperature (hereinafter, sometimes referred to as "thermosensitive water-soluble resin") can also be used.

[0063] As the heat-sensitive water-soluble resin, for example, a resin that decomposes when heated to a temperature equal to or higher than a specified modification temperature (e.g., 200°C or higher) and exposes polar functional groups to exhibit water solubility can be used. When the heat-sensitive water-soluble resin is heated to a temperature equal to or higher than the modification temperature, it is modified to be water-soluble.

[0064] However, the temperature of the heat-sensitive water-soluble resin can also be maintained below the modification temperature, and a filling layer can be formed while maintaining the state of being hardly soluble or insoluble in the aqueous liquid. When forming the filling layer, the temperature of the treatment liquid is set to a temperature below the modification temperature of the heat-sensitive water-soluble resin. As a result, a filling layer that is hardly soluble or insoluble in the aqueous liquid can be formed on the upper surface of the substrate W without modifying the heat-sensitive water-soluble resin to be water-soluble. In this case, the filling layer maintained in a block state can be removed from the substrate W without causing particles to fall off from the filling layer. Therefore, particles can be removed with a high removal rate.

[0065] Furthermore, as the solute contained in the treatment liquid, in addition to the heat-sensitive water-soluble resin, for example, acrylic resin, phenolic resin, epoxy resin, melamine resin, urea resin, unsaturated polyester resin, alkyd resin, polyurethane, polyimide, polyethylene, polypropylene, polyvinyl chloride, polystyrene, polyvinyl acetate, polytetrafluoroethylene, acrylonitrile-butadiene-styrene resin, acrylonitrile-styrene resin, polyamide, polyacetal, polycarbonate, polyvinyl alcohol, modified polyphenylene ether, polybutylene terephthalate, polyethylene terephthalate, polyphenylene sulfide, polysulfone, polyether ether ketone, polyamideimide, etc. can also be used.

[0066] The solvent preferably has a higher volatility than water. As the solvent, it is preferably PGEE (propylene glycol monoethyl ether).

[0067] In addition, the treatment liquid may also contain a sublimable substance. As the sublimable substance, various substances with a high vapor pressure at 5°C to 35°C and that change from a solid phase to a gas phase without passing through a liquid phase can be used. As the sublimable substance, for example, hexamethylenetetramine, 1,3,5-trioxane, ammonium 1-pyrrolidinedithiocarbamate, metaldehyde, paraffin with about 20 to 48 carbon atoms, tert-butanol, p-dichlorobenzene, naphthalene, L-menthol, fluorinated hydrocarbon compounds, etc. can be used. In particular, fluorinated hydrocarbon compounds can be used as the sublimable substance.

[0068] As the fluorinated hydrocarbon compound, for example, one or more of the following compounds (A) to (E) can be used.

[0069] Compound (A): fluoroalkane with 3 to 6 carbon atoms or its derivative;

[0070] Compound (B): fluorocycloalkane with 3 to 6 carbon atoms or its derivative;

[0071] Compound (C): a fluorinated bicyclic alkane having 10 carbon atoms or a derivative thereof;

[0072] Compound (D): fluorotetracyanoquinodimethane or a derivative thereof;

[0073] Compound (E): a fluorinated cyclophosphazene or a derivative thereof.

[0074] Furthermore, as Compound (A), examples include a fluorinated alkane having 3 to 6 carbon atoms represented by the formula (1) or a derivative thereof.

[0075] C m H n F2 m+2－n (1)

[0076] [In the formula, m represents a number from 3 to 6, and n represents a number where 0 ≤ n ≤ 2m + 1]

[0077] As the sublimable substance, it is particularly preferred to use 1,1,2,2,3,3,4-heptafluorocyclopentane. The vapor pressure of this compound at 20°C is about 8266 Pa, the melting point (freezing point) is 20.5°C, and the boiling point is 82.5°C. In addition, when mixing the sublimable substance in a molten state, as the solvent, a solvent that shows compatibility with the sublimable substance in a molten state is preferably used. In addition, when dissolving the sublimable substance as a solute, a solvent that shows solubility in the sublimable substance is preferably used.

[0078] In addition, when mixing the sublimable substance in a molten state, as the solvent, a solvent that shows compatibility with the sublimable substance in a molten state is preferably used. In addition, when dissolving the sublimable substance as a solute, a solvent that shows solubility in the sublimable substance is preferably used.

[0079] As the solvent, examples include at least one selected from the group consisting of DIW (Deionzied Water), pure water, aliphatic hydrocarbons, aromatic hydrocarbons, esters, alcohols, ethers, etc. Specifically, examples include at least one selected from the group consisting of DIW, pure water, methanol, ethanol, IPA (iso-Propyl alcohol), butanol, ethylene glycol, propylene glycol, NMP (N-methyl-2-pyrrolidone), DMF (N,N-dimethylformamide), DMA (dimethylacetamide), DMSO (dimethyl sulfoxide), hexane, toluene, PGMEA (propylene glycol monomethyl ether acetate), PGME (propylene glycol monomethyl ether), PGPE (propylene glycol monopropyl ether), PGEE (propylene glycol monoethyl ether), GBL (γ-butyrolactone), acetylacetone, 3-pentanone, 2-heptanone, ethyl lactate, cyclohexanone, dibutyl ether, HFE (hydrofluoroether), ethyl nonafluoroisobutyl ether, ethyl nonafluorobutyl ether, and hexafluoroiso-xylene.

[0080] The treatment liquid supply unit 132 includes a pipe 132a, a valve 132b, and a nozzle 132n. The nozzle 132n sprays the treatment liquid onto the upper surface Wa of the substrate W. The nozzle 132n is connected to the pipe 132a. The treatment liquid is supplied from a supply source to the pipe 132a. The valve 132b opens and closes the flow path in the pipe 132a. The nozzle 132n is preferably configured to be movable relative to the substrate W.

[0081] The removal liquid supply unit 134 supplies a removal liquid to the upper surface Wa of the substrate W. The filling layer formed by the solute of the treatment liquid can be removed using the removal liquid. By controlling the time of supplying the removal liquid, the filling layer can be selectively removed from the substrate W.

[0082] As the removal liquid, any solvent that is soluble in any resin can be used. For example, as the removal liquid, organic solvents such as diluents, toluene, acetates, alcohols, and glycols; acidic liquids such as acetic acid, formic acid, and glycolic acid can be used. It is particularly preferred to use a solvent having compatibility with an aqueous liquid. For example, as the removal liquid, isopropyl alcohol (IPA) is preferably used.

[0083] The removal liquid supply unit 134 includes a pipe 134a, a valve 134b, and a nozzle 134n. The nozzle 134n sprays the removal liquid onto the upper surface Wa of the substrate W. The nozzle 134n is connected to the pipe 134a. The removal liquid is supplied from a supply source to the pipe 134a. The valve 134b opens and closes the flow path in the pipe 134a. The nozzle 134n is preferably configured to be movable relative to the substrate W.

[0084] The water repellent supply unit 136 supplies a liquid water repellent to the upper surface Wa of the substrate W. By supplying the water repellent, a water repellent layer is formed on the upper surface Wa of the substrate W.

[0085] For example, the water repellent contains a compound having a methyl or silyl group at the end. Typically, hydroxyl groups (OH groups) exist on the surface of the groove, but using the water repellent, the hydroxyl groups on the surface of the substrate W are replaced with methyl or silyl groups. Furthermore, it is preferably that the water repellent does not change the characteristics of the filling layer.

[0086] For example, the water repellent is a water repellent that hydrophobizes silicon (Si) itself and silicon-containing compounds. Typically, the water repellent is a silane coupling agent. In one example, the silane coupling agent includes at least one of HMDS (hexamethyldisilazane), TMS (tetramethylsilane), fluorinated alkylchlorosilane, alkyldisilazane, and non-chlorine-based water repellents. The non-chlorine-based water repellent includes, for example, at least one of dimethylsilyldimethylamine, dimethylsilyldiethylamine, hexamethyldisilazane, tetramethyldisilazane, bis(dimethylamino)dimethylsilane, N,N-dimethylaminotrimethylsilane, N-(trimethylsilyl)dimethylamine, and organosilane compounds.

[0087] The water repellent supply unit 136 includes a pipe 136a, a valve 136b, and a nozzle 136n. The nozzle 136n sprays the water repellent onto the upper surface Wa of the substrate W. The nozzle 136n is connected to the pipe 136a. The water repellent is supplied from a supply source to the pipe 136a. The valve 136b opens and closes the flow path in the pipe 136a. The nozzle 136n is preferably configured to be movable relative to the substrate W.

[0088] The chemical solution supply unit 138 supplies a chemical solution to the upper surface Wa of the substrate W. By performing a chemical solution treatment using the chemical solution, the upper surface Wa of the substrate W can be chemically solution-treated. Through the chemical solution treatment, any one of etching, surface treatment, property imparting, forming a treatment film, and removing at least a part of the film can be performed on the substrate W. Typically, the chemical solution is an etching solution for etching the substrate W.

[0089] The chemical solution contains hydrofluoric acid. For example, the hydrofluoric acid can be heated to 40°C or higher and 70°C or lower, or can be heated to 50°C or higher and 60°C or lower. However, the hydrofluoric acid may not be heated. Additionally, the chemical solution may also contain water or phosphoric acid.

[0090] Furthermore, the chemical solution may also contain hydrogen peroxide water. Additionally, the chemical solution may contain SC1 (ammonia hydrogen peroxide mixture), SC2 (hydrochloric acid hydrogen peroxide mixture), or aqua regia (a mixture of concentrated hydrochloric acid and concentrated nitric acid).

[0091] The chemical solution supply unit 138 includes a pipe 138a, a valve 138b, and a nozzle 138n. The nozzle 138n sprays the chemical solution onto the upper surface Wa of the substrate W. The nozzle 138n is connected to the pipe 138a. The chemical solution is supplied from a supply source to the pipe 138a. The valve 138b opens and closes the flow path in the pipe 138a. The nozzle 138n is preferably configured to be movable relative to the substrate W.

[0092] Furthermore, as described above, the nozzles 132n, 134n, 136n, and 138n of the processing liquid supply unit 132, the removal liquid supply unit 134, the water repellent supply unit 136, and the chemical liquid supply unit 138 are also movable. The nozzles 132n, 134n, 136n, and 138n can move in the horizontal direction and / or the vertical direction following a moving mechanism controlled by the control unit 102. Furthermore, in this specification, it should be noted that the moving mechanism is omitted in order to avoid making the drawings too complex.

[0093] The substrate processing apparatus 100 further includes a susceptor 180. The susceptor 180 recovers the liquid splashed from the substrate W. The susceptor 180 moves up and down. For example, during the entire period when the liquid supply unit 130 supplies liquid to the substrate W, the susceptor 180 rises vertically upward to the side of the substrate W. In this case, the susceptor 180 recovers the liquid splashed from the substrate W due to the rotation of the substrate W. In addition, after the period when the liquid supply unit 130 supplies the processing liquid to the substrate W ends, the susceptor 180 descends vertically downward from the side of the substrate W.

[0094] As described above, the control device 101 includes a control unit 102 and a storage unit 104. The control unit 102 controls the substrate holding unit 120, the processing liquid supply unit 132, the removal liquid supply unit 134, the water repellent supply unit 136, and / or the susceptor 180. In one example, the control unit 102 controls the electric motor 124, the valves 132b, 134b, 136b, and / or 138b.

[0095] The substrate processing apparatus 100 of the present embodiment can be suitably used for manufacturing semiconductor elements provided with semiconductors. Typically, in semiconductor elements, a conductive layer and an insulating layer are stacked on a substrate. The substrate processing apparatus 100 can be suitably used for cleaning and / or processing (such as etching, property modification, etc.) of the conductive layer and / or the insulating layer during the manufacture of semiconductor elements.

[0096] Subsequently, with reference to Figures 1 to 3 , the substrate processing apparatus 100 of the present embodiment will be described. Figure 3 is a block diagram of the substrate processing apparatus 100.

[0097] As Figure 3 shown, the control device 101 controls various operations of the substrate processing apparatus 100. The control device 101 controls the indexing robot IR, the central robot CR, the substrate holding unit 120, and the liquid supply unit 130. Specifically, the control device 101 controls the indexing robot IR, the central robot CR, the substrate holding unit 120, and the liquid supply unit 130 by sending control signals to the indexing robot IR, the central robot CR, the substrate holding unit 120, and the liquid supply unit 130.

[0098] Specifically, the control unit 102 controls the indexing robot IR and transfers the substrate W by means of the indexing robot IR.

[0099] The control unit 102 controls the central robot CR and transfers the substrate W by means of the central robot CR. For example, the central robot CR receives the unprocessed substrate W and transfers the substrate W into any one of the plurality of chambers 110. In addition, the central robot CR receives the processed substrate W from the chamber 110 and transfers out the substrate W.

[0100] The control unit 102 controls the substrate holding unit 120 to control the start of rotation, the change in rotational speed, and the stop of rotation of the substrate W. For example, the control unit 102 can control the substrate holding unit 120 to change the rotational speed of the substrate holding unit 120. Specifically, the control unit 102 can change the rotational speed of the substrate W by changing the rotational speed of the electric motor 124 of the substrate holding unit 120.

[0101] The control unit 102 can separately control the valves 132b, 134b, 136b, and 138b of the liquid supply unit 130, so that the states of the valves 132b, 134b, 136b, and 138b are switched between the open state and the closed state. Specifically, by controlling the valves 132b, 134b, 136b, and 138b of the liquid supply unit 130 and setting the valves 132b, 134b, 136b, and 138b to the open state, the control unit 102 can allow the processing liquid, the removal liquid, the water repellent, and the chemical solution flowing in the pipes 132a, 134a, 136a, and 138a to pass through the nozzles 132n, 134n, 136n, and 138n. In addition, by controlling the valves 132b, 134b, 136b, and 138b of the liquid supply unit 130 and setting the valves 132b, 134b, 136b, and 138b to the closed state, the control unit 102 can separately stop the supply of the processing liquid, the removal liquid, the water repellent, and the chemical solution flowing in the pipes 132a, 134a, 136a, and 138a to the nozzles 132n, 134n, 136n, and 138n.

[0102] The substrate processing apparatus 100 of the present embodiment can be suitably used for forming semiconductor elements. For example, the substrate processing apparatus 100 is suitable for processing the substrate W used as a semiconductor element having a stacked structure. The semiconductor element is a so-called 3D-structured memory (storage device). As an example, the substrate W is suitably used as a NAND type flash memory.

[0103] Subsequently, with reference to Figure 4 , the substrate W that is made into the semiconductor element 300 using the substrate processing apparatus 100 of the present embodiment will be described. Figure 4 (a) is a schematic side view of the semiconductor element 300 fabricated by processing the substrate W using the substrate processing apparatus 100, Figure 4FIG. (b) is a schematic top view of the semiconductor element 300, Figure 4 FIG. (c) is Figure 4 a partial enlarged view of FIG. (b). Furthermore, in Figure 4 , the direction orthogonal to the main surface of the base material S of the substrate W is represented as the z direction, and the directions orthogonal to the z direction are represented as the x direction and the y direction.

[0104] As Figure 4 shown in FIG. (a), the substrate W has a base material S and a stacked structure L. The base material S is in the form of a thin film extending in the xy plane. The stacked structure L is formed on the upper surface of the base material S. The base material S supports the stacked structure L. The stacked structure L is formed so as to extend in the z direction from the upper surface of the base material S.

[0105] Furthermore, Figure 4 the substrate W shown in FIG. (a) preferably further has an etch stop layer Es between the base material S and the stacked structure L. The etch stop layer Es is formed of, for example, aluminum oxide (Al2O3). By etching, the stacked structure L is partially removed, thereby forming a groove R, which will be described in detail later. In Figure 4 the example of

[0106] , the groove R is a memory hole. The etching is stopped by the etch stop layer Es.

[0107] The stacked structure L has an insulating layer N and a conductive layer M. The insulating layer N and the conductive layer M are alternately stacked. For example, the insulating layer N is formed of a silicon oxide film. In addition, the conductive layer M is formed of a metal. For example, the conductive layer M contains tungsten (W).

[0108] A plurality of insulating layers N extend in parallel with the upper surface of the base material S, respectively. A conductive layer M is provided between two adjacent insulating layers N. Two adjacent insulating layers N are supported by the conductive layer M.

[0109] For example, the thickness (length in the z direction) of the insulating layer N is 1 nm or more and 50 nm or less. In addition, for example, the thickness (length in the z direction) of the conductive layer M is 1 nm or more and 50 nm or less.

[0110] The sum of the thickness of one layer of the insulating layer N and the thickness of one layer of the conductive layer M is 20 nm or more and 100 nm or less. The stacked structure L includes 10 or more and 100 or less insulating layers N and 10 or more and 100 or less conductive layers M.

[0111] The diameter (aperture) of the groove R is on the nanometer scale. For example, the diameter of the groove R is 20 nm or more and 300 nm or less. The diameter of the groove R can also be 50 nm or more and 200 nm.

[0112] Preferably, the groove R is formed perpendicular to the main surface of the substrate S. The diameter of the surface portion of the groove R (tip diameter Wt) is 20 nm or more and 300 nm or less, and is 50 nm or more and 200 nm.

[0113] For example, the aspect ratio of the groove R is 10 or more. The aspect ratio represents the ratio of the height to the width of the groove R. In addition, heretofore, memory holes with a height of about 1 μm have been reported to be formed with an aspect ratio of 40 - 50, and it is considered that the aspect ratio will further increase in the future. For example, the upper limit of the aspect ratio of the groove R can be 100, or can also be 200.

[0114] In Figure 4 In the semiconductor element 300 shown in (a) of , a cylindrical charge holding layer H is disposed in the groove R of the substrate W. A cylindrical channel layer Ch is disposed inside the charge holding layer H. For example, the channel layer Ch is formed of polysilicon. A cylindrical dielectric layer D is disposed inside the channel layer Ch. The dielectric layer D is formed of a silicon oxide film.

[0115] The charge holding layer H can also have a three-layer structure. For example, the charge holding layer H includes a cylindrical inner layer H1, a cylindrical intermediate layer H2, and a cylindrical outer layer H3. The outer layer H3 is in contact with the stacked structure L. The intermediate layer H2 is disposed inside the outer layer H3. The inner layer H1 is disposed inside the intermediate layer H2. The inner layer H1 is in contact with the channel layer Ch. Therefore, the dielectric layer D, the channel layer Ch, the inner layer H1, the intermediate layer H2, and the outer layer H3 are disposed from the center of the groove R of the stacked structure L.

[0116] For example, the inner layer H1 is formed of a silicon oxide film. The inner layer H1 is also called a tunnel layer.

[0117] For example, the intermediate layer H2 is formed of a silicon nitride film. The intermediate layer H2 stores charges. The intermediate layer H2 is also called a charge storage layer.

[0118] For example, the outer layer H3 is formed of a silicon oxide film. The outer layer H3 is also called a blocking layer.

[0119] By applying a voltage to the conductive layer M and the channel layer Ch, charges are stored in the corresponding intermediate layer H2. As shown in (a) of Figure 4 A memory element Se is formed corresponding to the conductive layer M. Therefore, the number of memory elements Se corresponding to the number of conductive layers M is formed in one groove R.

[0120] Furthermore, as shown in Figure 4As shown in FIG. (b), a plurality of grooves R are formed in the substrate W, and the grooves R are regularly arranged in the substrate W. A charge holding layer H, a channel layer Ch, and a dielectric layer D are respectively arranged in the grooves R. The plurality of grooves R are designed to have the same diameter and height. For example, the difference in the top diameter Wt of each groove R may be 5% or less, or may be 3% or less.

[0121] Typically, the grooves R are formed by dry etching the stacked structure L. When the grooves R are formed by dry etching the stacked structure L, there is a case where the diameter of the deep part of the groove R is smaller than the diameter of the surface side of the groove R. In particular, if the height of the stacked structure L and / or the number of stacked layers of the stacked structure L increases, the diameter of the deep part of the groove R is likely to be smaller than the diameter of the surface side of the groove R. In addition, the shorter the processing time of dry etching in order to increase the throughput, the more likely the diameter of the deep part of the groove R is to be smaller than the diameter of the surface side of the groove R.

[0122] As shown in Figure 4 FIG. (a), a plurality of memory elements Se are formed in the groove R. Therefore, it is preferable that the diameter of the groove R is constant from the surface side portion to the deep part. However, when the groove R is formed in the stacked structure L, there is a case where the diameter of the groove R is not constant. When the diameters of the grooves R are different, if a memory element is formed in the groove R, there is a case where the electrical characteristics of the memory element are not constant and the characteristics of the memory element cannot be made uniform.

[0123] In addition, generally, the smaller the diameter of the groove R, the more memory elements can be formed on the substrate. Therefore, in order to increase the memory capacity, it is preferable that the diameter of the groove R is small. However, if the diameter of the groove R is small, the flow of the etching fluid for etching the groove R is likely to become insufficient. Therefore, when the groove R is etched, etching deviation is likely to occur depending on the position of the groove R. Specifically, the surface side portion of the groove R is relatively easy to etch, while the deep part of the groove R is relatively difficult to etch.

[0124] According to the present embodiment, even if the diameter of the groove R is small, it is possible to selectively etch the deep part of the groove R (hereinafter referred to as "groove deep part Rf"), and the details will be described later. Thereby, the non-uniformity of the diameter of the groove R can be suppressed.

[0125] Next, with reference to Figure 5 , the method for forming a semiconductor element according to the present embodiment will be described. A part of the method for forming a semiconductor element according to the present embodiment is performed using the substrate processing apparatus 100 described above with reference to Figures 1 to 3 .

[0126] As shown in Figure 5As shown in (a), the substrate W has a base material S and a stacked structure L. The base material S is in the form of a film that unfolds in the xy plane. The stacked structure L is formed on the upper surface of the base material S. The stacked structure L is formed so as to extend in the z direction from the upper surface of the base material S. For example, the stacked structure L is formed of a silicon oxide film (SiO2) and a silicon nitride film (SiN). The stacked structure L has a surface La.

[0127] The stacked structure L has an insulating layer N and a sacrificial layer Sa. The insulating layer N and the sacrificial layer Sa are alternately stacked. A plurality of insulating layers N extend in parallel with the upper surface of the base material S respectively. A plurality of sacrificial layers Sa are provided between two adjacent insulating layers N. Two adjacent insulating layers N are supported by the sacrificial layer Sa. Furthermore, in the process of manufacturing the semiconductor element 300, the sacrificial layer Sa is Figure 4 replaced by the conductive layer M shown.

[0128] For example, the thickness (length in the z direction) of the insulating layer N is 1 nm or more and 50 nm or less. The insulating layer N is formed of a silicon oxide film.

[0129] In addition, for example, the thickness (length in the z direction) of the sacrificial layer Sa is 1 nm or more and 50 nm or less. In one example, the sacrificial layer Sa is formed of a silicon nitride film.

[0130] As Figure 5 shown in (b), a groove R is formed in the stacked structure L. Typically, the groove R is formed by dry etching. Preferably, the diameter (length in the xy plane) of the groove R formed by dry etching is constant from the surface side to the deep part, but in reality, there are cases where the diameter of the groove R is not constant from the surface side to the deep part. Especially when the processing time of dry etching is shortened to increase the throughput of the substrate W, it is difficult to keep the diameter of the groove R constant from the surface side to the deep part. In this case, the diameter of the deep part Rf of the groove is smaller than the diameter of the surface side part Rn of the groove R.

[0131] Furthermore, for example, the deep part Rf of the groove represents the part of the groove R on the side of the base material S. The surface side part Rn of the groove R represents the part of the groove R on the surface side.

[0132] As Figure 5 shown in (c), the groove R of the substrate W is deformed. For example, the diameter of the deep part Rf of the groove is selectively made larger than the diameter of the deep part Rf of the groove after dry etching. In one example, the diameter of the deep part Rf of the groove extends with a length of less than 10 nm in the xy plane. Thereby, the diameter of the groove R of the substrate W can be made uniform from the surface side to the deep part.

[0133] As Figure 5 shown in (d), a charge holding layer H is formed inside the groove R of the stacked structure L.

[0134] As shown in Figure 5 (e) thereof, a channel layer Ch and a dielectric layer D are formed inside a charge retention layer H. Thereafter, a sacrificial layer Sa is replaced with a conductive layer M. In this manner, a semiconductor element 300 as shown in Figure 4 can be formed.

[0135] Furthermore, in Figure 5 (b), in order to avoid making the description too complicated, it is shown that the diameter of the groove R linearly changes from the surface side to the deep part, but the present embodiment is not limited thereto. Due to the warping phenomenon, there is a case where the diameter of the groove R becomes the largest near the central part.

[0136] Subsequently, with reference to Figure 6 , a general method for forming a semiconductor element will be described. Figure 6 (a) to Figure 6 (g) of are schematic views for explaining a general method for forming a semiconductor element.

[0137] As shown in Figure 6 (a) thereof, a groove R is provided in a stacked structure L of a substrate W. As shown in Figure 6 (b) thereof, a filling layer F is filled in the groove R. As shown in Figure 6 (c) thereof, a removing liquid Ds is applied to the substrate W. The removing liquid Ds partially dissolves the filling layer F filled in the groove R. As a result, a partially filled layer Fp that partially fills the deep part Rf of the groove is formed from the filling layer F. As shown in Figure 6 (d) thereof, a water repellent P is supplied to the substrate W. Thereafter, the removing liquid Ds is replaced with the water repellent P. Since the surface side portion Rn of the groove R is not covered with the partially filled layer Fp, the surface of the stacked structure L reacts with the water repellent P in the surface side portion Rn of the groove R to form a coating film Ps.

[0138] As shown in Figure 6 (e) thereof, the partially filled layer Fp and the water repellent P are removed. As shown in Figure 6 (f) thereof, the groove R is etched with a chemical solution C. Regarding the deep part Rf of the groove, since the insulating layer N and the sacrificial layer Sa are exposed, they are etched by the chemical solution C. Therefore, as shown in Figure 6 (f) thereof, the region Re located in the deep part Rf of the groove is removed by the chemical solution C so as to widen the diameter of the groove R. As shown in Figure 6 (g) thereof, the chemical solution C and the coating film Ps are removed.

[0139] Subsequently, with reference to Figure 7 and Figure 8 , the state of the surface of the stacked structure L will be described. Figure 7 (a) to Figure 7(c) is a schematic diagram for explaining the surface state of the silicon oxide film of the insulating layer N as a comparative example. Figure 6 ) is a schematic diagram for explaining the surface state of the silicon oxide film of the insulating layer N as a comparative example.

[0140] As Figure 7 shown in (a) of, there are a plurality of adsorption sites 10 on the surface of the insulating layer N. Each of the plurality of adsorption sites 10 contains a hydroxyl group. An adsorption site represents a region on the solid surface as an adsorption medium that adsorbs molecules as adsorbates.

[0141] As Figure 7 shown in (b) of, if a water repellent P ( Figure 6 (d) of ) is supplied to the surface of the insulating layer N, the water repellent P reacts with the hydroxyl group of the adsorption site 10 to form a coating film Ps ( Figure 6 (d) of ). Specifically, by substituting the hydroxyl group of the adsorption site 10 with a methyl group or a silyl group of the water repellent P, the molecule PsM of the material of the coating film Ps is adsorbed on the surface of the insulating layer N. As a result, a coating film Ps is formed on the insulating layer N.

[0142] As Figure 7 shown in (c) of, even when the chemical solution C ( Figure 6 (f) of ) is supplied, a coating film Ps is formed on the insulating layer N, so the insulating layer N is not etched. In other words, the coating film Ps protects the insulating layer N from the influence of the chemical solution C. Further in other words, the coating film Ps functions as a protective film.

[0143] Figure 8 (a) to Figure 8 (c) of is a schematic diagram for explaining the surface state of the silicon nitride film of the sacrificial layer Sa ( Figure 6 ) as a comparative example.

[0144] As Figure 8 shown in (a) of, there are a plurality of adsorption sites 11 on the surface of the sacrificial layer Sa. Each of the plurality of adsorption sites 11 contains a hydroxyl group. However, the number of adsorption sites 11 per unit area on the surface of the sacrificial layer Sa is less than Figure 7 the number of adsorption sites 11 per unit area on the surface of the insulating layer N shown in (a) of. The reason is that the sacrificial layer Sa is a silicon nitride film.

[0145] As Figure 8 shown in (b) of, if a water repellent P ( Figure 6 (d) of ) is supplied to the surface of the sacrificial layer Sa, the water repellent P reacts with the hydroxyl group of the adsorption site 10 to form a coating film Ps ( Figure 6(d)). Specifically, by substituting the hydroxyl group of the adsorption site 11 with the methyl group or silyl group of the water repellent P, the molecule PsM of the material of the coating film Ps is adsorbed on the surface of the sacrificial layer Sa. As a result, the coating film Ps is formed on the sacrificial layer Sa.

[0146] However, since the number of adsorption sites 10 on the surface of the sacrificial layer Sa is small ( Figure 8 (a)), the non-adsorbed region 20 where the molecule PsM of the coating film Ps is not adsorbed may increase compared to the coating film Ps on the insulating layer N ( Figure 7 (b)). A larger non-adsorbed region 20 indicates a reduction in the function of the coating film Ps as a protective film.

[0147] As Figure 8 (c) shows, when the liquid medicine C is supplied ( Figure 6 (f)), since there are many non-adsorbed regions 20 on the coating film Ps on the sacrificial layer Sa, the liquid medicine C may etch the part of the sacrificial layer Sa corresponding to the non-adsorbed region 20. In this case, on the sacrificial layer Sa, the function of the coating film Ps as a protective film is reduced.

[0148] Here, as Figure 6 (d) shows, by supplying the water repellent P to the groove R, the coating film Ps is formed on the insulating layer N and the sacrificial layer Sa at the same time. Therefore, from Figure 7 and Figure 8 , it can be seen that for the insulating layer N on the surface side part Rn of the groove R, since the function of the coating film Ps as a protective film is not reduced, the liquid medicine C will not etch it. On the other hand, for the sacrificial layer Sa on the surface side part Rn of the groove R, since the function of the coating film Ps as a protective film is reduced, the liquid medicine C may etch it. That is, the liquid medicine C may etch the sacrificial layer Sa in the part (surface side part Rn) of the groove R where the diameter does not need to be enlarged.

[0149] Therefore, in the method for forming a semiconductor element of the present embodiment, before forming the second coating film Ps2 ( Figure 11 (a)) corresponding to the coating film Ps, the first coating film Ps1 ( Figure 9 (b)) with a larger number of adsorption sites is formed.

[0150] Subsequently, with reference to Figures 9 to 13 , the method for forming a semiconductor element of the present embodiment will be described. Figures 9 to 13 is a schematic diagram for explaining the method for forming a semiconductor element of the present embodiment. Figures 9 to 13 The method for forming a semiconductor element shown is suitably used as a part of the method for forming a semiconductor element described with reference to Figure 5 . For example,Figures 9 to 13 The semiconductor element forming method shown deforms the groove R shown in Figure 5 (c) of. The semiconductor element forming method of the present embodiment is performed using the substrate processing apparatus 100 described with reference to Figures 1 to 3 .

[0151] First, as shown in Figure 9 (a) of, a groove R is provided in the stacked structure L. For example, by etching the substrate W, the groove R is formed in the stacked structure L. Here, the groove R is formed in the insulating layer N and the sacrificial layer Sa. The groove R reaches the etching stop layer Es. The insulating layer N is typically a silicon oxide film. The sacrificial layer Sa is typically a silicon nitride film.

[0152] Subsequently, as shown in Figure 9 (b) of, a first coating film Ps1 is formed from the deep part Rf of the groove to the surface side part Rn. Typically, the first coating film Ps1 is a silicon oxide film. The thickness (length in the x direction) of the first coating film Ps1 is, for example, 0.1 nm or more and 10 nm or less.

[0153] Typically, the first coating film Ps1 is formed in the groove R by the ALD (Atomic Layer Deposition) method. The ALD method is a film forming method in which atomic layers are deposited layer by layer by repeating the supply and blowing of gaseous raw materials (precursors). The ALD method utilizes the self-control of atoms. According to the ALD method, the first coating film Ps1 can be formed with high precision and uniformity. Furthermore, an ALD apparatus (not shown) forms the first coating film Ps1 by the ALD method.

[0154] Furthermore, the method for forming the first coating film Ps1 is not particularly limited. For example, the first coating film Ps1 can be formed by supplying ozone water, hydrogen peroxide water, or a sulfuric acid / hydrogen peroxide mixture (SPM) to the groove R.

[0155] Subsequently, as shown in Figure 10 (a) of, the groove R is filled with a filling layer F so as to cover the first coating film Ps1. The filling layer F is, for example, an organic substance (carbon-based material). In one example, the filling layer F is a polymer. The filling layer F can also be formed of a resist. For example, if the solvent is volatilized from the processing liquid after the processing liquid is supplied to the substrate W in the processing liquid supply unit 132, the filling layer F is formed from the solute of the processing liquid. Here, the filling layer F fills from the deep part Rf of the groove to the surface side part Rn so as to cover the first coating film Ps1.

[0156] Preferably, the treatment liquid becomes solid after being applied to the substrate W. The treatment liquid itself is in a liquid state, but after the treatment liquid is coated on the substrate W, the solvent volatilizes, and thus the solute becomes solid, forming the filling layer F.

[0157] Subsequently, as shown in (b) of Figure 10 , the removal liquid Ds is applied to the substrate W. The removal liquid Ds dissolves the filling layer F. Here, the removal liquid Ds partially dissolves the filling layer F filled in the groove R. Thus, in a state where the deep part Rf of the groove is filled with the filling layer F, the surface side part Rn of the groove R is replaced by the removal liquid Ds. As a result, a partially filled layer Fp that partially fills the deep part Rf of the groove is formed by the filling layer F. Furthermore, the removal liquid Ds does not dissolve the first coating film Ps1.

[0158] For example, the removal liquid supply unit 134 supplies the removal liquid Ds to the substrate W. The removal liquid supply unit 134 supplies the removal liquid Ds in a time and amount set such that the filling layer F is not completely dissolved but partially dissolved. For example, the removal liquid Ds contains isopropyl alcohol (IPA).

[0159] Typically, more than half of the depth of the groove R is replaced by the removal liquid Ds, and the filling layer F remaining less than half of the depth of the groove R becomes the partially filled layer Fp. For example, the depth (length in the z-axis direction) of the partially filled layer Fp is 1 / 3 or less of the depth of the groove R.

[0160] Subsequently, as shown in (a) of Figure 11 , the water repellent P is supplied. For example, the water repellent supply unit 136 supplies the water repellent P to the substrate W. The partially filled layer Fp is not affected by the water repellent P, and the removal liquid Ds is replaced by the water repellent P. Thus, in a state where the deep part Rf of the groove is filled with the partially filled layer Fp, the removal liquid Ds on the surface side part Rn of the groove R is replaced by the water repellent P.

[0161] Furthermore, although the deep part Rf of the groove is covered by the partial filling layer Fp, the surface side part Rn of the groove R is not covered by the partial filling layer Fp. Therefore, when the water repellent P is supplied, on the surface side part Rn of the groove R, the surface of the first coating film Ps1 reacts with the water repellent P to form a second coating film Ps2 on the first coating film Ps1. The second coating film Ps2 includes, for example, a molecular film of an organosilane compound generated by a silane coupling reaction. In one example, the silane coupling agent includes at least one of HMDS (hexamethyldisilazane), TMS (tetramethylsilane), fluorinated alkylchlorosilane, alkyldisilazane, and a non-chlorine-based water repellent. The non-chlorine-based water repellent includes, for example, at least one of dimethylsilyldimethylamine, dimethylsilyldiethylamine, hexamethyldisilazane, tetramethyldisilazane, bis(dimethylamino)dimethylsilane, N,N-dimethylaminotrimethylsilane, N-(trimethylsilyl)dimethylamine, and an organosilane compound. The thickness (length in the x direction) of the second coating film Ps2 is, for example, 0.5 nm or more and 5 nm or less. Furthermore, since the first coating film Ps1 is the base of the second coating film Ps2, the first coating film Ps1 can also be referred to as a base film.

[0162] The deep part Rf of the groove is the part of the groove R that is not covered by the second coating film Ps2. In other words, the deep part Rf of the groove is the part of the groove R that is closer to the substrate S side than the second coating film Ps2. Furthermore, in other words, the deep part Rf of the groove is the part of the groove R that is located deeper than the second coating film Ps2.

[0163] Subsequently, as shown in (b) of Figure 11 , the partial filling layer Fp and the water repellent P are removed. In this case, a part of the water repellent P on the surface side of the groove R is removed together with the partial filling layer Fp in the deep part Rf of the groove. At this time, it is preferable that particles as residues when forming the groove R (for example, during dry etching) are also removed. By removing the partial filling layer Fp, the first coating film Ps1 is exposed in the deep part Rf of the groove. On the other hand, the surface side part Rn of the groove R is still covered by the second coating film Ps2. The second coating film Ps2 covers the first coating film Ps1.

[0164] For example, in order to remove the partial filling layer Fp and the water repellent P, a removal liquid can also be applied. In one example, the removal liquid contains IPA. For example, the removal liquid supply unit 134 supplies the removal liquid Ds to the substrate W. The removal liquid supply unit 134 supplies the removal liquid in a time and amount set so as to completely dissolve the partial filling layer Fp.

[0165] Alternatively, in order to remove the partial filling layer Fp and the water repellent P, the substrate W can also be heated. For example, when the partial filling layer Fp is formed of a sublimable substance, the partial filling layer Fp can be sublimated by heating.

[0166] Subsequently, as shown in (a) of Figure 12 , the groove R is etched using the first liquid medicine C1. Typically, the first liquid medicine C1 includes hydrofluoric acid. For example, the first liquid medicine C1 contains hydrofluoric acid (dilute hydrofluoric acid) diluted in the range of 1:100 to 1:2000. For example, the hydrofluoric acid can be heated to 40 °C or higher and 70 °C or lower, and can also be heated to 50 °C or higher and 60 °C or lower. Alternatively, the first liquid medicine C1 can also contain water or deionized water (DIW). Alternatively, the first liquid medicine C1 can also contain phosphoric acid. Alternatively, the first liquid medicine C1 can also be phosphoric acid containing fluoride. The phosphoric acid containing fluoride is phosphoric acid containing fluoride. In this case, the fluoride is ammonium fluoride or ammonium bifluoride.

[0167] Since the first coating film Ps1 ( Figure 11 in (b)) is exposed in the deep part Rf of the groove, the first coating film Ps1 is etched by the first liquid medicine C1. If the first coating film Ps1 in the deep part Rf of the groove is etched, the insulating layer N and the sacrificial layer Sa are exposed. As a result, in the deep part Rf of the groove, the insulating layer N and the sacrificial layer Sa are etched by the first liquid medicine C1. In this case, the first liquid medicine C1 is a liquid that etches the insulating layer N and the sacrificial layer Sa at substantially the same speed. Therefore, the deep part Rf of the groove is etched by the first liquid medicine C1 at substantially the same speed. Furthermore, in Figure 12 (a), in order to avoid making the drawings complicated, the diameters of the etched deep parts Rf of the grooves are made substantially the same. In addition, in the deep part Rf of the groove, only the first coating film Ps1 can be etched by the first liquid medicine C1. In this case, all of the first coating film Ps1 can be etched, or a part of the first coating film Ps1 can be etched.

[0168] On the other hand, the surface side part Rn of the groove R is covered with the second coating film Ps2, so it is not etched by the first liquid medicine C1. Therefore, as shown in (a) of Figure 12 , the region Re1 located in the deep part Rf of the groove is removed by the first liquid medicine C1, and the diameter of the groove R is enlarged in a widened manner.

[0169] In this case, for example, when aiming to finally enlarge the diameter of the deep part Rf of the groove by U [nm], the diameter of the deep part Rf of the groove is enlarged by V [nm]. V [nm] is less than U [nm]. The reason for enlarging the diameter of the deep part Rf of the groove by V [nm] is that when removing the first coating film Ps1 in the later stage ( Figure 13 (a)), the insulating layer N and the sacrificial layer Sa in the deep part Rf of the groove are etched. Furthermore, the etching amount of the first liquid medicine C1 is adjusted by the etching time, for example.

[0170] Furthermore, the first liquid chemical C1 is a liquid that etches the first coating film Ps1 but does not etch the second coating film Ps2, or a liquid that hardly etches the second coating film Ps2.

[0171] Subsequently, as shown in Figure 12 (b) thereof, the first liquid chemical C1 and the second coating film Ps2 are removed. The removal of the first liquid chemical C1 and the second coating film Ps2 can also be performed by ultraviolet irradiation or heating. In addition, at this time, it is preferably that the residue during dry etching is also removed. Furthermore, by supplying SPM to the groove R, the first liquid chemical C1 and the second coating film Ps2 can also be removed.

[0172] Subsequently, as shown in Figure 13 (a) thereof, the first coating film Ps1 is removed using the second liquid chemical C2. The second liquid chemical C2 is, for example, the same as the first liquid chemical C1 used in the step of Figure 12 (a). That is, the second liquid chemical C2 includes hydrofluoric acid. For example, the second liquid chemical C2 contains hydrofluoric acid (dilute hydrofluoric acid) diluted in the range of 1:100 to 1:2000. For example, the hydrofluoric acid can be heated to 40 °C or higher and 70 °C or lower, and can also be heated to 50 °C or higher and 60 °C or lower. Alternatively, the second liquid chemical C2 can also contain water or DIW. Alternatively, the second liquid chemical C2 can also contain phosphoric acid. Alternatively, the second liquid chemical C2 can also be fluoride-containing phosphoric acid. The fluoride-containing phosphoric acid is phosphoric acid containing fluoride. In this case, the fluoride is ammonium fluoride or ammonium bifluoride.

[0173] In the groove R, the first coating film Ps1 on the surface side portion Rn is etched (removed) by the second liquid chemical C2, and the insulating layer N and the sacrificial layer Sa in the deep part Rf of the groove are etched by the second liquid chemical C2. Therefore, the region Re2 located in the deep part Rf of the groove is removed by the second liquid chemical C2, and the diameter of the groove R expands in a manner that further widens. The diameter of the deep part Rf of the groove can widen in a manner that is equal to the diameter (top diameter) near the groove R.

[0174] In this case, the second liquid chemical C2 is a liquid that etches the first coating film Ps1, the insulating layer N, and the sacrificial layer Sa at substantially the same speed. Therefore, in the groove R, the first coating film Ps1 on the surface side portion Rn, and the insulating layer N and the sacrificial layer Sa in the deep part Rf of the groove are etched by the second liquid chemical C2 at substantially the same speed. Furthermore, in Figure 13 (a), in order to avoid making the drawings complicated, the diameter of the deep part Rf of the groove after etching is set to be substantially the same. In addition, when the first coating film Ps1 remains in the deep part Rf of the groove, the first coating film Ps1, the insulating layer N, and the sacrificial layer Sa are etched by the second liquid chemical C2.

[0175] Here, for example, when aiming to finally expand the diameter of the deep part Rf of the groove by U [nm], inFigure 12 In step (a), the diameter of the deep part Rf of the groove is enlarged by V [nm]. V [nm] is less than U [nm]. Thus, in Figure 13 In step (a), for example, etching is performed using the second liquid C2 in such a way that the diameter of the deep part Rf of the groove is enlarged by (U - V) [nm]. Furthermore, the etching amount using the second liquid C2 is adjusted, for example, by the etching time.

[0176] Subsequently, as Figure 13 shown in (b), the second liquid C2 is removed from the groove R.

[0177] In the above manner, the diameter of the groove R of the stacked structure L can be adjusted. Furthermore, in Figure 13 , for the sake of facilitating understanding of the change in the shape of the groove R, it is illustrated in such a way that the diameter of the deep part Rf of the groove is equal to the top diameter (caliber) of the groove R and the diameter of the deep part Rf of the groove is larger than the diameter of the central part of the groove R, but it should be noted that this is only an example. For the groove R, the diameter of the deep part Rf of the groove may also be enlarged in such a way that the diameter of the deep part Rf of the groove is equal to the diameter of the central part of the groove R. Alternatively, the groove R may also be deformed in such a way that the diameter of the deep part Rf of the groove is equal to the top diameter and the central part diameter of the groove R. In these aspects, Figure 12 the same also applies.

[0178] Furthermore, in Figure 10 In (b), by applying the removing liquid Ds, a part of the filling layer F is replaced by the removing liquid Ds. When the diameter of the groove R is small, it takes a long time for the removing liquid Ds to remove the entire filling layer F. Therefore, by interrupting the removal process of the filling layer F using the removing liquid Ds halfway through the time when the removing liquid Ds removes the entire filling layer F, the filling layer F can be partially removed. In addition, as Figure 10 shown in (b), by adjusting the amount and treatment time of the removing liquid Ds, etc., a partially filled layer Fp that covers an appropriate part can be left.

[0179] In addition, in Figure 10 In (b), the partially filled layer Fp is formed from the filling layer F using the removing liquid Ds, but the present embodiment is not limited thereto. When the filling layer F is formed of a sublimable substance, the partially filled layer Fp may also be formed from the filling layer F by heating. In this case, the partially filled layer Fp that partially fills the deep part Rf of the groove may also be formed from the filling layer F by adjusting the heating time and temperature.

[0180] Furthermore, the substrate W is preferably used as a memory having a plurality of memory elements Se. Typically, when the substrate W is used as a memory, a plurality of grooves R having a constant diameter and height are provided in the substrate W. Therefore, a plurality of grooves used in a memory with a large storage capacity can be deformed simultaneously by the same process.

[0181] Furthermore, when forming the groove R in the stacked structure L, due to the warping phenomenon, there is a case where the diameter of the groove R becomes the largest near the central portion. In this case, it is preferable that the second coating film Ps2 covers the vicinity of the central portion. In addition, the diameter of the deep portion Rf of the groove may be enlarged by etching so as to be equal to the diameter of the largest central portion of the groove R.

[0182] Furthermore, in the above description of (a) of Figure 11 , the second coating film Ps2 is formed by supplying a liquid water repellent P to the groove R filled with the partial filling layer Fp, but the present embodiment is not limited thereto. The second coating film Ps2 may also be formed by a gas.

[0183] Next, with reference to Figure 14 , the state of the surface of the first coating film Ps1 when forming the second coating film Ps2 will be described. Figure 14 (a) to Figure 14 (c) of Figure 14 are schematic views for explaining the state of the surface when forming the second coating film Ps2 on the first coating film Ps1. Figure 14 (a) to Figure 9 (c) of Figure 9 show the first coating film Ps1 ([[]]

[0184] As shown in Figure 14 (a) of Figure 7 , there are a plurality of adsorption sites 12 on the surface of the first coating film Ps1. Each of the plurality of adsorption sites 12 contains a hydroxyl group. The number of adsorption sites 12 per unit area on the surface of the first coating film Ps1 is substantially the same as the number of adsorption sites 10 ([[]] Figure 8 (a) of

[0185] As shown in Figure 14As shown in (b) of, when a water repellent P is supplied to the surface of the first coating film Ps1, the water repellent P reacts with the hydroxyl groups at the adsorption sites 12 to form a second coating film Ps2 ( Figure 11 of (a)). Specifically, by substituting the hydroxyl groups at the adsorption sites 12 with methyl or silyl groups of the water repellent P, molecules PsM of the material of the second coating film Ps2 are adsorbed on the surface of the first coating film Ps1. As a result, a second coating film Ps2 is formed on the first coating film Ps1. In this case, since the number of adsorption sites 12 on the surface of the first coating film Ps1 is large ( Figure 14 of (a)), compared with the coating film Ps of the comparative example ( Figure 8 of (b)), in the second coating film Ps2, the non-adsorption region 20 ( Figure 8 of (b)) is extremely small. Therefore, regardless of the sacrificial layer Sa and the insulating layer N, the function of the second coating film Ps2 as a protective film is higher than that of the coating film Ps of the comparative example ( Figure 8 of (b)).

[0186] As Figure 14 shown in (c) of, even when the first liquid medicine C1 is supplied ( Figure 12 of (a)), the second coating film Ps2 is formed, so the sacrificial layer Sa is not etched. In other words, the second coating film Ps2 effectively protects the sacrificial layer Sa from the influence of the first liquid medicine C1. Further in other words, the second coating film Ps2 effectively functions as a protective film. Specifically, since the number of adsorption sites 12 on the surface of the first coating film Ps1 is large ( Figure 14 of (a)), regardless of the sacrificial layer Sa and the insulating layer N, compared with the coating film Ps of the comparative example ( Figure 8 of (b)), the function of the second coating film Ps2 as a protective film is higher.

[0187] As described above, as referred to Figure 14 above, according to the present embodiment, the number of adsorption sites 12 per unit area for adsorbing the material of the second coating film Ps2 on the surface of the first coating film Ps1 is larger than the number of adsorption sites per unit area on the surface of a specific layer among the different layers (insulating layer N and sacrificial layer Sa) constituting the laminated structure L. In this case, the specific layer represents the layer with the smallest number of adsorption sites per unit area among the different layers (insulating layer N and sacrificial layer Sa) constituting the laminated structure L. In the present embodiment, the specific layer is the sacrificial layer Sa. Thus, in the present embodiment, since the number of adsorption sites 12 on the surface of the first coating film Ps1 is large, regardless of the sacrificial layer Sa and the insulating layer N, compared with the coating film Ps of the comparative example ( Figure 8Compared with (b) thereof, the function of the second coating film Ps2 as a protective film is higher. Therefore, it is possible to suppress the first liquid chemical C1 from etching the insulating layer N and the sacrificial layer Sa in the portion (surface side portion Rn) of the groove R in the substrate W where the diameter does not need to be enlarged.

[0188] In particular, in the present embodiment, the adsorption site 12 on the surface of the first coating film Ps1 contains a hydroxyl group. Therefore, by using a compound having a methyl or silyl group at the end as the water repellent P, it is possible to easily form the second coating film Ps2 on the first coating film Ps1.

[0189] Here, in the present embodiment, in the groove R, the first coating film Ps1 is formed so as to cover the insulating layer N and the sacrificial layer Sa ( Figure 9 of (b)). Therefore, a second coating film Ps2 having a higher function as a protective film is formed on the first coating film Ps1 ( Figure 11 of (a)). As a result, in Figure 12 step (a), the insulating layer N and the sacrificial layer Sa in the surface side portion Rn of the groove R are not etched by the first liquid chemical C1. That is, it is possible to suppress the first liquid chemical C1 from etching the portion (surface side portion Rn of the groove R) in the groove R where the diameter does not need to be enlarged. On the other hand, it is possible to etch the portion (groove deep portion Rf) in the groove R where the diameter needs to be enlarged by the first liquid chemical C1.

[0190] Especially in Figure 6 the semiconductor element forming method of the comparative example shown, since the function of the coating film Ps on the sacrificial layer Sa as a protective film is reduced, the sacrificial layer Sa in the portion (surface side portion Rn of the groove R) in the groove R where the diameter does not need to be enlarged may be etched ( Figure 8 of (c)). In contrast, in the semiconductor element forming method of the present embodiment, by forming the second coating film Ps2 after forming the first coating film Ps1 on the sacrificial layer Sa and the insulating layer N, it is possible to not only suppress the first liquid chemical C1 from etching the insulating layer N but also suppress the first liquid chemical C1 from etching the sacrificial layer Sa.

[0191] Subsequently, with reference to Figure 15 the semiconductor element forming method of the present embodiment will be described. Figure 15 is a flowchart of the semiconductor element forming method. The semiconductor element forming method of the present embodiment is preferably carried out by referring to Figures 1 to 3 the substrate processing apparatus 100 described.

[0192] First, in step S10, the first coating film Ps1 is formed in the groove R ( Figure 9(b)). Typically, a first coating film Ps1 is formed from the surface side portion Rn to the deep portion Rf of the groove R. Specifically, the first coating film Ps1 is formed, and the first coating film Ps1 covers the groove R of the laminated structure L supported by the substrate S. Accordingly, the insulating layer N and the sacrificial layer Sa exposed in the groove R are covered by the first coating film Ps1.

[0193] Subsequently, in step S20, the groove R is partially covered in the laminated structure L ( Figure 11 (a), Figure 11 (b)). Typically, the surface side portion Rn of the groove R is selectively covered. Specifically, a second coating film Ps2 is formed, and the second coating film Ps2 selectively covers the surface side portion Rn (the portion on the surface side) of the groove R on which the first coating film Ps1 is formed from the first coating film Ps1. The second coating film Ps2 covers the surface side portion Rn of the groove R and does not cover the deep portion Rf of the groove. Accordingly, the first coating film Ps1 is exposed in the deep portion Rf of the groove.

[0194] Subsequently, in step S30, the diameter of the deep portion Rf of the groove is enlarged. By applying a liquid medicine (first liquid medicine C1, second liquid medicine C2) to the groove R, the diameter of the deep portion Rf of the groove can be enlarged ( Figure 12 (a), Figure 13 (a)). Since the groove R is partially covered by the second coating film Ps2, the diameter of the deep portion Rf of the groove R that is not covered by the second coating film Ps2 can be partially enlarged. Accordingly, since the diameter of the deep portion Rf of the groove can be enlarged, the diameter of the groove R can be adjusted.

[0195] As described above, as referred to Figure 15 In the present embodiment, the second coating film Ps2 is formed on the first coating film Ps1 on the surface side portion Rn of the groove R (steps S10, S20). Accordingly, the function of the second coating film Ps2 as a protective film is improved. As a result, in step S30, it is possible to suppress the etching of the sacrificial layer Sa and the insulating layer N in the portion (surface side portion Rn) of the groove R of the substrate W that does not need to have its diameter enlarged by the liquid medicine (first liquid medicine C1) ( Figure 12 (a)).

[0196] Subsequently, with reference to Figure 16 the method for forming a semiconductor element according to the present embodiment will be described. Figure 16 is a flowchart of the method for forming a semiconductor element. The method for forming a semiconductor element according to the present embodiment is preferably carried out by referring to Figures 1 to 3 the substrate processing apparatus 100 described above.

[0197] First, in step S10, the first coating film Ps1 is formed ( Figure 9(b)), the first coated film Ps1 is coated and provided in the groove R of the stacked structure L supported by the base material S of the substrate W. In this case, for example, the first coated film Ps1 is formed by the ALD method using an ALD apparatus outside the substrate processing apparatus 100. Further, the first coated film Ps1 may also be formed by ozone water, hydrogen peroxide water, or SPM. In this case, the liquid supply unit 130 of the substrate processing apparatus 100 may, for example, also include a fluid supply unit having the same configuration as the processing liquid supply unit 132. And the fluid supply unit supplies ozone water, hydrogen peroxide water, or SPM to the upper surface Wa of the substrate W. Further, when the insulating layer N is a silicon oxide film and the sacrificial layer Sa is a silicon nitride film, by supplying ozone water, hydrogen peroxide water, or SPM to the groove R, a first coated film Ps1 including a silicon oxide film can be formed.

[0198] Next, in step Sa, the substrate W is carried into the substrate processing apparatus 100. Here, the substrate W has a base material S and a stacked structure L, a groove R is provided in the stacked structure L, and a first coated film Ps1 is formed in the groove R.

[0199] Next, in step S20, the groove R is partially covered with a second coated film Ps2 from above the first coated film Ps1. Here, the partial covering of the groove R in step S20 is performed through the formation of the filling layer F in step S21, the partial removal of the filling layer F (formation of the partial filling layer Fp) in step S22, the supply of a water repellent (formation of the second coated film Ps2) in step S23, and the removal of the partial filling layer Fp in step S24.

[0200] First, in step S21, the filling layer F is filled in the groove R ( Figure 10 (a)). Specifically, the filling layer F that fills the groove R is formed from above the first coated film Ps1. For example, the processing liquid supply unit 132 supplies a processing liquid to the substrate W. Thereby, the groove R of the substrate W is filled with the filling layer F. Further, typically, after supplying the processing liquid, the substrate holding unit 120 increases the rotation speed of the substrate W and flings the processing liquid remaining on the surface of the substrate W to the outside of the substrate W.

[0201] Next, in step S22, a part of the filling layer F is removed ( Figure 10 (b)). That is, after forming the filling layer F (after step S21), the filling layer F is partially removed. For example, the removal liquid supply unit 134 supplies a removal liquid Ds to the substrate W for a predetermined time. By applying the removal liquid Ds to the filling layer F in the groove R, the filling layer F is partially dissolved, and a partial filling layer Fp is formed in the groove R. The time for applying the removal liquid Ds is set so as to partially remove the filling layer F in the groove R. At this time, the filling layer F on the surface side portion Rn of the groove R is removed, and a partial filling layer Fp remains in the deep portion Rf of the groove.

[0202] Alternatively, a partial filling layer Fp can also be formed in the groove R by heating the filling layer F for a specified time. For example, when the filling layer F contains a sublimable substance, by heating the filling layer F for a specified time, a part of the filling layer F sublimes, and a partial filling layer Fp can be formed in the groove R.

[0203] Here, step S21 and step S22 are an example of "the step of forming a partial filling layer Fp that partially fills the deep part Rf of the groove R in the first coating film Ps1".

[0204] Subsequently, in step S23, a water repellent P ( Figure 11 (a)) is supplied to the substrate W. That is, after the partial filling layer Fp is formed (after step S22), the water repellent P is supplied. The water repellent supply unit 136 supplies the water repellent P to the substrate W. By applying the water repellent to the groove R in which the partial filling layer Fp is formed in the deep part Rf, the water repellent P fills the surface side portion Rn of the groove R where the partial filling layer Fp is not formed, and a water repellent layer is formed. The water repellent layer is formed on the first coating film Ps1. At this time, on the surface side portion Rn of the groove R, the characteristics of the first coating film Ps1 change due to the water repellent P, and a second coating film Ps2 is formed on the surface side portion Rn of the groove R. Thus, by supplying the water repellent P, a second coating film Ps2 is formed as a part of the water repellent layer on the surface side portion Rn of the groove R from the first coating film Ps1.

[0205] Subsequently, in step S24, the partial filling layer Fp ( Figure 11 (b)) is removed. That is, after the second coating film Ps2 is formed on the surface side of the groove R from the first coating film Ps1 by supplying the water repellent P (after step S23), the partial filling layer Fp and the water repellent P are removed.

[0206] Here, the part of the water repellent layer formed by the water repellent P other than the second coating film Ps2 is removed, and the partial filling layer Fp is removed. For example, the removal liquid supply unit 134 supplies a removal liquid Ds to the substrate W to dissolve the partial filling layer Fp and replace the part of the water repellent layer other than the second coating film Ps2. At this time, the surface side portion Rn of the groove R is covered by the second coating film Ps2 from the first coating film Ps1, and the first coating film Ps1 is exposed in the deep part Rf of the groove.

[0207] Alternatively, the partial filling layer Fp can also be removed by heating the partial filling layer Fp for a specified time. For example, when the filling layer F contains a sublimable substance, by heating the filling layer F, a part of the filling layer F sublimes, and the partial filling layer Fp can be removed from the groove R.

[0208] Subsequently, in step S30, the diameter of the deep part Rf of the groove is enlarged. For example, the deep part Rf of the groove R that is not covered with the second coating film Ps2 is partially etched, and the groove diameter becomes wider.

[0209] Here, the enlargement of the diameter of the deep part Rf of the groove in step S30 is performed by etching with the first chemical solution C1 in step S31, removal of the second coating film Ps2 in step S32, and removal of the first coating film Ps1 in step S33.

[0210] First, in step S31, the first chemical solution C1 is supplied to the groove R ( Figure 12 as shown in (a)). For example, the chemical solution supply unit 138 supplies the first chemical solution C1 to the substrate W. Thereby, the deep part Rf of the groove R that is not covered with the second coating film Ps2 is partially etched. That is, the deep part Rf of the groove is etched with the first chemical solution C1 to enlarge the diameter of the deep part Rf of the groove that is not covered with the second coating film Ps2 in the groove R.

[0211] Subsequently, in step S32, the second coating film Ps2 is removed from the groove R ( Figure 12 as shown in (b)). That is, after step S31 of etching with the first chemical solution C1, the second coating film Ps2 is removed. For example, the second coating film Ps2 can also be removed by ashing the second coating film Ps2 by ultraviolet irradiation or heat treatment. Furthermore, step S32 can also be performed outside the substrate processing apparatus 100. In addition, the second coating film Ps2 can also be removed by supplying SPM. In this case, the liquid supply unit 130 of the substrate processing apparatus 100 can, for example, also include a fluid supply unit having the same configuration as the processing liquid supply unit 132. And the fluid supply unit supplies SPM to the upper surface Wa of the substrate W.

[0212] Subsequently, in step S33, the first coating film Ps1 is removed from the groove R ( Figure 13 as shown in (a)). That is, after step S32 of removing the second coating film Ps2, the first coating film Ps1 is removed. Specifically, the first coating film Ps1 is removed by supplying the second chemical solution C2 to the groove R. In the present embodiment, the second chemical solution C2 is the same as the first chemical solution C1. For example, the chemical solution supply unit 138 supplies the second chemical solution C2 to the substrate W. Thereby, the first coating film Ps1 in the groove R is removed by the second chemical solution C2. In addition, the deep part Rf of the groove is further etched by the second chemical solution C2. Thereafter, after the removal and etching of the first coating film Ps1 are completed, the second chemical solution C2 is removed from the groove R ( Figure 13 as shown in (b)).

[0213] Subsequently, in step Sb, the substrate W is unloaded from the substrate processing apparatus 100. In the above manner, a substrate W with suppressed variation in groove diameter can be formed.

[0214] As described above, with reference to Figure 16 As described above, according to the present embodiment, a first coating film Ps1 is formed in the groove R (step S10), and a second coating film Ps2 is formed on the first coating film Ps1 (step S20). Therefore, in the surface-side portion Rn of the groove R, it is possible to suppress not only the etching of the insulating layer N by the first chemical solution C1 but also the etching of the sacrificial layer Sa by the first chemical solution C1. That is, it is possible to suppress the etching of the portion (surface-side portion Rn) of the groove R of the substrate W where the diameter does not need to be enlarged by the first chemical solution C1.

[0215] In addition, in the present embodiment, the material of the first coating film Ps1 is different from the material of the second coating film Ps2. Therefore, by performing the step S32 of removing the second coating film Ps2 and the step S33 of removing the first coating film Ps1 at different times and using methods corresponding to the properties of the first coating film Ps1 and the second coating film Ps2, respectively, it is possible to effectively remove the first coating film Ps1 and the second coating film Ps2.

[0216] Furthermore, in the present embodiment, in step S33, the first coating film Ps1 is removed using the second chemical solution C2, and the groove deep part Rf is etched using the second chemical solution C2. Therefore, while considering the thickness (length in the x direction) of the first coating film Ps1 to be removed, the diameter of the groove deep part Rf is enlarged to the target value.

[0217] Furthermore, in the present embodiment, a partial filling layer Fp that partially fills the groove deep part Rf is formed on the first coating film Ps1, and thereafter, the second coating film Ps2 is formed using a water repellent P (step S20). In this way, the second coating film Ps2 can be formed on the first coating film Ps1 in the surface-side portion Rn of the groove R through a simple process.

[0218] Specifically, in the present embodiment, a filling layer F is formed on the first coating film Ps1 (step S21), and further, after a partial filling layer Fp is formed in the groove deep part Rf (step S22), the second coating film Ps2 is formed using a water repellent P (step S23). Therefore, the second coating film Ps2 can be easily formed on the first coating film Ps1 in the surface-side portion Rn of the groove R.

[0219] Subsequently, with reference to Figure 17 the substrate processing apparatus 100 of the present embodiment will be described. Figure 17 is a schematic diagram of the substrate processing apparatus 100. The substrate processing apparatus 100 can process a plurality of substrates W together.

[0220] The substrate processing apparatus 100 includes a substrate holding unit 120 and a liquid supply unit 130. The liquid supply unit 130 includes a processing liquid supply unit 132, a removal liquid supply unit 134, a water repellent supply unit 136, and a chemical liquid supply unit 138. The processing liquid supply unit 132, the removal liquid supply unit 134, the water repellent supply unit 136, and the chemical liquid supply unit 138 store liquids respectively.

[0221] The processing liquid supply unit 132 includes a processing liquid storage tank 132t. A processing liquid is stored in the processing liquid storage tank 132t. A filling layer is formed from the processing liquid. For example, the processing liquid contains a solute and a volatile solvent. Alternatively, the processing liquid contains a sublimable substance.

[0222] The removal liquid supply unit 134 includes a removal liquid storage tank 134t. A removal liquid is stored in the removal liquid storage tank 134t. The filling layer formed from the processing liquid can be removed by the removal liquid. By controlling the time for supplying the removal liquid, the filling layer can be selectively removed from the substrate W.

[0223] As the removal liquid, any solvent that is soluble in any resin can be used. As the removal liquid, for example, organic solvents such as diluents, toluene, acetates, alcohols, and glycols; acidic liquids such as acetic acid, formic acid, and glycolic acid can be used.

[0224] The water repellent supply unit 136 includes a water repellent storage tank 136t. A liquid water repellent is stored in the water repellent storage tank 136t. A water repellent layer is formed on the substrate W using the water repellent. The water repellent is a water repellent that hydrophobizes silicon (Si) itself and silicon-containing compounds. The water repellent is, for example, a silane coupling agent. The silane coupling agent includes, for example, at least one of HMDS (hexamethyldisilazane), TMS (tetramethylsilane), fluorinated alkylchlorosilane, alkyldisilazane, and non-chlorine-based water repellents. The non-chlorine-based water repellent includes, for example, at least one of dimethylsilyldimethylamine, dimethylsilyldiethylamine, hexamethyldisilazane, tetramethyldisilazane, bis(dimethylamino)dimethylsilane, N,N-dimethylaminotrimethylsilane, N-(trimethylsilyl)dimethylamine, and organosilane compounds.

[0225] The chemical liquid supply unit 138 includes a chemical liquid storage tank 138t. A chemical liquid is stored in the chemical liquid storage tank 138t. The substrate W can be chemically processed by using the chemical liquid. By the chemical processing, any one of etching, surface treatment, property imparting, processing film formation, and removal of at least a part of the film can be performed on the substrate W. Typically, the chemical liquid is an etching liquid for etching the substrate W. In the present embodiment, the chemical liquid is used as the first chemical liquid C1 and the second chemical liquid C2.

[0226] The liquid medicine contains hydrofluoric acid. For example, the liquid medicine contains hydrofluoric acid diluted in the range of 1:100 to 1:2000 (dilute hydrofluoric acid). For example, the hydrofluoric acid can be heated to above 40°C and below 70°C, or can be heated to above 50°C and below 60°C. However, the hydrofluoric acid may not be heated. In addition, the liquid medicine may also contain water or phosphoric acid.

[0227] Furthermore, the liquid medicine may also contain hydrogen peroxide water. In addition, the liquid medicine may contain SC1 (ammonia hydrogen peroxide mixture), SC2 (hydrochloric acid hydrogen peroxide mixture) or aqua regia (mixture of concentrated hydrochloric acid and concentrated nitric acid). Or, the liquid medicine may be fluoride-containing phosphoric acid. The fluoride-containing phosphoric acid is phosphoric acid containing fluoride. In this case, the fluoride is ammonium fluoride or ammonium bifluoride.

[0228] The substrate holding part 120 holds the substrate W. The normal direction of the main surface of the substrate W held by the substrate holding part 120 is parallel to the Y direction. The substrate holding part 120 moves the substrate W while holding a plurality of substrates W. For example, the substrate holding part 120 moves upward or downward in the vertical direction while holding the substrate W. Or, the substrate holding part 120 may move in the horizontal direction while holding the substrate W.

[0229] The substrate holding part 120 includes a main body plate 122b and holding rods 124b. The main body plate 122b is a plate extending in the vertical direction (Z direction). The holding rods 124b extend in the horizontal direction (Y direction) from one main surface of the main body plate 122b. Here, two holding rods 124b extend in the Y direction from one main surface of the main body plate 122b. For a plurality of substrates W, in a state where the plurality of substrates W are arranged in the front-back direction of the paper surface, the lower edges of the respective substrates W abut against the plurality of holding rods 124b to hold the erected posture (vertical posture).

[0230] The substrate processing apparatus 100 further includes a control device 101. The control device 101 includes a control part 102 and a storage part 104. The control part 102 controls the substrate holding part 120.

[0231] In the substrate processing apparatus 100 of the present embodiment, the control part 102, in the same manner as in the single-wafer type, processes the substrate W held on the substrate holding part 120 with different liquids, whereby it is possible to adjust the diameter of the groove R of the layer structure L provided on the substrate W in the same manner as the method described with reference to Figures 9 to 16 the single-wafer type.

[0232] In addition, in the present embodiment, the first coating film Ps1 is formed in the groove R of the substrate W by the ALD method, and the substrate W is carried into the substrate processing apparatus 100. However, the first coating film Ps1 may also be formed by ozone water, hydrogen peroxide water, or SPM. In this case, the liquid supply unit 130 includes, for example, a fluid supply unit having the same configuration as the processing liquid supply unit 132 for storing ozone water, hydrogen peroxide water, or SPM.

[0233] Furthermore, in the present embodiment, the second coating film Ps2 may also be removed by supplying SPM. In this case, the liquid supply unit 130 includes, for example, a fluid supply unit having the same configuration as the processing liquid supply unit 132 for storing SPM.

[0234] Here, in the description with reference to Figures 1 to 17 storage element Se is disposed in the groove R of the substrate W, but the present embodiment is not limited thereto. A dummy storage element having the same configuration as the storage element Se but not usable as a storage element may also be formed in the groove R of the substrate W. Alternatively, a contact plug for electrically connecting to the storage element Se may also be formed in the groove R of the substrate W.

[0235] Subsequently, with reference to Figure 18 a semiconductor element 300 formed by the semiconductor element forming method of the present embodiment will be described. Figure 18 is a schematic diagram of the semiconductor element 300.

[0236] A plurality of grooves R are provided in the semiconductor element 300. The plurality of grooves R include, in addition to the memory groove Rs in which the storage element Se is disposed, a contact groove Rc in which a contact plug Cp is disposed. The contact groove Rc is electrically connected to the conductive layer M.

[0237] According to the semiconductor element forming method of the present embodiment, not only can the diameter of the memory groove Rs be made uniform from the surface portion to the deep portion, but also the diameter of the contact groove Rc can be made uniform from the surface portion to the deep portion. Therefore, the strength of supporting the semiconductor element through the contact groove Rc can be made uniform.

[0238] As described above, embodiments of the present invention have been described with reference to the accompanying drawings. However, the present invention is not limited to the above-described embodiments and can be implemented in various ways without departing from the gist thereof. In addition, by appropriately combining a plurality of constituent elements disclosed in the above-described embodiments, various inventions can be formed. For example, several constituent elements may be deleted from all the constituent elements shown in the embodiments. Further, constituent elements related to different embodiments may be appropriately combined. In the drawings, for easy understanding, each constituent element is schematically shown as the main body, and for ease of drawing, there are cases where the thickness, length, number, interval, etc. of each constituent element shown in the drawing are different from the actual ones. In addition, the materials, shapes, dimensions, etc. of the constituent elements shown in the above-described embodiments are examples and are not particularly limited, and various changes can be made without substantially departing from the effects of the present invention.

[0239] [Industrial Applicability]

[0240] The present invention can be suitably used for a method of forming a semiconductor element.

[0241]

Explanation of Reference Numerals

[0242] 100: Substrate processing apparatus

[0243] 110: Chamber

[0244] 120: Substrate holding part

[0245] 130: Liquid supply part

[0246] 132: Processing liquid supply part

[0247] 134: Removing liquid supply part

[0248] 136: Water repellent supply part

[0249] 138: Chemical liquid supply part

[0250] W: Substrate

Claims

1. A method for forming a semiconductor device, wherein, Comprising: A step of forming a first coating film, wherein the first coating film covers a groove of a stacked structure supported by a substrate; A step of forming a second coating film, wherein the second coating film selectively covers a portion on the surface side in the groove in which the first coating film is formed on the first coating film; and A step of etching the deep part of the groove with a first chemical solution in order to widen the width of the deep part of the groove which is a portion not covered by the second coating film in the groove.

2. The method for forming a semiconductor device as claimed in claim 1, wherein, Further comprising: A step of removing the second coating film after the step of etching with the first chemical solution; And A step of removing the first coating film after the step of removing the second coating film.

3. The method for forming a semiconductor element according to claim 2, wherein In the step of removing the first coating film, the first coating film is removed with a second chemical solution, and the deep part of the groove is etched with the second chemical solution.

4. The method for forming a semiconductor element according to claim 1 or 2, wherein In the step of forming the first coating film, the first coating film is formed by atomic layer deposition, ozone water, hydrogen peroxide water, or a mixed solution of sulfuric acid and hydrogen peroxide water.

5. The method for forming a semiconductor element according to claim 1 or 2, wherein The number of adsorption sites per unit area for adsorbing the material of the second coating film on the surface of the first coating film is greater than the number of adsorption sites per unit area on the surface of a specific layer among different layers constituting the stacked structure, The specific layer represents the layer with the least number of adsorption sites per unit area among different layers constituting the stacked structure.

6. The method for forming a semiconductor element according to claim 5, wherein The adsorption sites include hydroxyl groups.

7. The method for forming a semiconductor element according to claim 1 or 2, wherein The step of forming the second coating film includes: A step of forming a partially filled layer that partially fills the deep part of the groove from the first coating film; A step of supplying a water repellent after forming the partially filled layer; and A step of removing the partially filled layer and the water repellent after forming the second coating film from the first coating film on the surface side of the groove by supplying the water repellent.

8. The method for forming a semiconductor element according to claim 7, wherein The step of forming the partially filled layer includes: A step of forming a filling layer that fills the groove from the first coating film; and A step of partially removing the filling layer after forming the filling layer.

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