Semiconductor device formation method

Abstract

To provide a semiconductor element formation method capable of inhibiting etching using chemical from being performed on a part whose width is not needed to be enlarged of a recess of a substrate.SOLUTION: A semiconductor element formation method includes: a step S10 of forming a first coating film Ps1 for coating a recess R provided on a lamination structure L supported by a base material S; a step S20 of forming a second coating film Ps2 for selectively coating portions positioned on the surface side of the recess R on which the first coating film Ps1 is formed, from above the first coating film Ps1; and a step S31 of etching a recess deep portion Rf, which is the recess R's portion not coated by the second coating film Ps2, using first chemical C1 so as to extend the width of the recess deep portion Rf.SELECTED DRAWING: Figure 16

Description

Technical Field

[0001] The present invention relates to a method for forming a semiconductor device.

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 etching. In the step of forming the coating layer, a coating layer is formed that selectively coats a portion of a recess provided in a stacked structure supported by a substrate and located on the surface side of the stacked structure. In the step of etching, the deep part of the recess is etched with a chemical solution so as to widen the diameter of the deep part of the recess more than that of the coating layer.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] 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 form a coating layer on layers of different materials at the same time.

[0005] The inventors of this invention focused on adsorption sites for adsorbing molecules that make up the coating layer in each layer made of different materials and conducted extensive research. As a result, they found that the number of adsorption sites for adsorbing molecules that make up the coating layer in a layer made of one material may be less than the number of adsorption sites in a layer made of another material. As a result, the inventors of this invention hypothesized that in layers with fewer adsorption sites, the non-adsorbed region where molecules that make up the coating layer are not adsorbed may increase. Furthermore, the inventors of this invention hypothesized that if the non-adsorbed region in the coating layer increases, etching with a chemical solution may occur in parts of the layer where it is not necessary to widen the diameter in the recess. "Diameter" is an example of "width".

[0006] The present invention has been made in view of the above problems, and its objective is to provide a semiconductor device formation method that can suppress etching by chemical solution in parts of the substrate recess that do not need to be widened. [Means for solving the problem]

[0007] According to one aspect of the present invention, a semiconductor device formation method includes the steps of: forming a first coating film that covers a recess provided in a laminated structure supported on a substrate; forming a second coating film that selectively covers the surface portion of the recess on which the first coating film is formed, from above the first coating film; and etching the recess depth with a first chemical solution to widen the width of the recess depth, which is the portion of the recess not covered by the second coating film.

[0008] In one embodiment, the method 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.

[0009] In one embodiment, the step of removing the first coating film involves removing the first coating film with the second chemical solution and etching the deep recess with the second chemical solution.

[0010] In one embodiment, the first coating film is formed in the step of forming the first coating film by the ALD method, ozonated water, hydrogen peroxide solution, or a sulfuric acid hydrogen peroxide solution mixture.

[0011] In one embodiment, 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 the different layers constituting the laminated structure. The specific layer is the layer with the fewest adsorption sites per unit area among the different layers constituting the laminated structure.

[0012] In one embodiment, the adsorption site includes a hydroxyl group.

[0013] In one embodiment, the step of forming the second coating film includes the steps of forming a partial filling layer that partially fills the deeper part of the recess from above the first coating film, supplying a water repellent after forming the partial filling layer, and removing the partial filling layer and the water repellent after forming the second coating film on the surface side of the recess from above the first coating film by supplying the water repellent.

[0014] In one embodiment, the step of forming the partial filling layer includes the steps of forming a filling layer that fills the recess from above the first coating film, and the steps of partially removing the filling layer after it has been formed. [Effects of the Invention]

[0015] According to the present invention, etching with a chemical solution can be suppressed in areas of the substrate recess that do not need to be widened. [Brief explanation of the drawing]

[0016] [Figure 1] This is a schematic diagram of the substrate processing apparatus of this embodiment. [Figure 2]It is a schematic diagram of the substrate processing apparatus of the present embodiment. [Figure 3] It is a block diagram of the substrate processing apparatus of the present embodiment. [Figure 4] (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 partially enlarged view of (b). [Figure 5] (a) to (e) are schematic diagrams for explaining the method of forming a semiconductor element of the present embodiment. [Figure 6] (a) to (g) are schematic diagrams for explaining the method of forming a semiconductor element according to a comparative example. [Figure 7] (a) to (c) are schematic diagrams for explaining the state of the surface of the insulating layer of the laminated structure of the substrate according to a comparative example. [Figure 8] (a) to (c) are schematic diagrams for explaining the state of the surface of the sacrificial layer of the laminated structure of the substrate according to a comparative example. [Figure 9] (a) and (b) are schematic diagrams for explaining the method of forming a semiconductor element of the present embodiment. [Figure 10] (a) and (b) are schematic diagrams for explaining the method of forming a semiconductor element of the present embodiment. [Figure 11] (a) and (b) are schematic diagrams for explaining the method of forming a semiconductor element of the present embodiment. [Figure 12] (a) and (b) are schematic diagrams for explaining the method of forming a semiconductor element of the present embodiment. [Figure 13] (a) and (b) are schematic diagrams for explaining the method of forming a semiconductor element of the present embodiment. [Figure 14] (a) to (c) are schematic diagrams for explaining the state of the surface of the first coating film of the present embodiment. [Figure 15] It is a flowchart of the method of forming a semiconductor element of the present embodiment. [Figure 16] It is a flowchart of the method of forming a semiconductor element of the present embodiment. [Figure 17] It is a schematic diagram of the substrate processing apparatus of the present embodiment. [Figure 18] This is a schematic diagram of a semiconductor device formed by the semiconductor device formation method of this embodiment. [Modes for carrying out the invention]

[0017] Embodiments of the semiconductor device formation method according to the present invention will be described below with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and the description will not be repeated. In this specification, mutually orthogonal X, Y, and Z axes may be described to facilitate understanding of the invention. Typically, the X and Y axes are parallel to the horizontal direction, and the Z axis is parallel to the vertical direction. In addition, in this specification, mutually orthogonal x, y, and z axes may be described to facilitate understanding of the invention. Typically, the x and y axes extend parallel to the main surface of the substrate or base material, and the z axis extends perpendicular to the main surface of the substrate or base material.

[0018] First, an embodiment of the substrate processing apparatus 100 according to the present invention will be described with reference to Figure 1. Figure 1 is a schematic plan view of the substrate processing apparatus 100 of this embodiment.

[0019] The substrate processing apparatus 100 processes the substrate W. The substrate processing apparatus 100 processes the substrate W by performing at least one of the following: etching, surface treatment, characterization, formation of a treatment film, removal of at least a portion of the film, and cleaning.

[0020] The substrate W is used as a semiconductor substrate. The substrate W includes a semiconductor wafer. For example, the substrate W is roughly disc-shaped. Here, the substrate processing apparatus 100 processes the substrate W one sheet at a time.

[0021] As shown in Figure 1, the substrate processing apparatus 100 comprises a plurality of chambers 110, a fluid cabinet 100A, a fluid box 100B, a plurality of load ports LP, an indexer robot IR, a center robot CR, and a control device 101. The control device 101 controls the load ports LP, the indexer robot IR, and the center robot CR.

[0022] Each load port LP accommodates multiple substrates W stacked together. The indexer robot IR transports the substrates W between the load port LP and the center robot CR. The center robot CR transports the substrates W between the indexer robot IR and the chamber 110. Each chamber 110 processes the substrates W by discharging a liquid onto them. The liquid includes a processing liquid, a removal liquid, a water repellent, and / or a chemical solution. The fluid cabinet 100A contains the liquid. The fluid cabinet 100A may also contain gas.

[0023] Specifically, the multiple chambers 110 form multiple towers TW (four towers TW in Figure 1) arranged to surround the central robot CR in a plan view. Each tower TW contains multiple chambers 110 (three chambers 110 in Figure 1) stacked vertically. Each fluid box 100B corresponds to one of the multiple towers TW. The liquid in the fluid cabinet 100A is supplied to all chambers 110 in the tower TW corresponding to one of the fluid boxes 100B via one of the fluid boxes 100B. Similarly, the gas in the fluid cabinet 100A is supplied to all chambers 110 in the tower TW corresponding to one of the fluid boxes 100B via one of the fluid boxes 100B.

[0024] The control device 101 controls various operations of the substrate processing device 100. The control device 101 includes a control unit 102 and a storage unit 104.

[0025] The control unit 102 has a processor. The control unit 102 may have, for example, a central processing unit (CPU). Alternatively, the control unit 102 may have a general-purpose computing unit.

[0026] The storage unit 104 stores data and computer programs. The data includes recipe data. The recipe data includes information indicating multiple recipes. Each of the multiple recipes specifies the processing content and processing procedure for the substrate W.

[0027] The storage unit 104 includes a main memory and an auxiliary storage device. The main memory 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 removable media. The storage unit 104 corresponds to an example of a non-temporary computer-readable storage medium. The control unit 102 executes the computer program stored in the storage unit 104 to perform board processing operations.

[0028] Next, the substrate processing apparatus 100 of this embodiment will be described with reference to Figure 2. Figure 2 is a schematic diagram of the substrate processing apparatus 100.

[0029] The substrate processing apparatus 100 comprises a chamber 110, a substrate holding section 120, and a liquid supply section 130. The chamber 110 houses the substrate W. The substrate holding section 120 holds the substrate W.

[0030] Chamber 110 is a roughly box-shaped chamber with an internal space. Chamber 110 houses the substrates W. Here, the substrate processing apparatus 100 is a single-wafer type that processes substrates W one at a time, and each chamber 110 houses one substrate W. The substrates W are housed in and processed within the chamber 110. At least a portion of the substrate holding section 120 and the liquid supply section 130 are housed in the chamber 110.

[0031] The substrate holder 120 holds the substrate W. The substrate holder 120 holds the substrate W horizontally so that the upper surface (front surface) Wa of the substrate W faces upward and the back surface (bottom surface) Wb of the substrate W faces vertically downward. The substrate holder 120 also rotates the substrate W while holding it. As will be described in detail later, the upper surface Wa of the substrate W is provided with a laminated structure in which recesses are formed. A recess refers to a concave part formed in the substrate W. For example, a recess is a hole or trench formed in the substrate W. A hole is, for example, a memory hole.

[0032] For example, the substrate holder 120 may be a clamping type that clamps the edges of the substrate W. Alternatively, the substrate holder 120 may have any mechanism for holding the substrate W from the back surface Wb. For example, the substrate holder 120 may be a vacuum type. In this case, the substrate holder 120 holds the substrate W horizontally by adhering the central part of the back surface Wb of the substrate W, which is the non-device forming surface, to its upper surface. Alternatively, the substrate holder 120 may combine a clamping type and a vacuum type, where a plurality of chuck pins contact the peripheral edge surface of the substrate W.

[0033] For example, the substrate holding section 120 includes a spin 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 spin base 121. The chuck member 122 chucks the substrate W. Typically, the spin base 121 is provided with multiple chuck members 122.

[0034] The shaft 123 is a hollow shaft. The shaft 123 extends vertically along the rotation axis Ax. The spin base 121 is coupled to the upper end of the shaft 123. The substrate W is placed above the spin base 121.

[0035] The spin base 121 is disc-shaped and horizontally supports the substrate W. The shaft 123 extends downward from the center of the spin base 121. The electric motor 124 provides rotational force to the shaft 123. By rotating the shaft 123 in the rotational direction, the electric motor 124 rotates the substrate W and the spin base 121 around the rotation axis Ax. The housing 125 surrounds the shaft 123 and the electric motor 124.

[0036] 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.

[0037] 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 solution supply unit 138. At least a portion of the processing liquid supply unit 132, the removal liquid supply unit 134, the water repellent supply unit 136, and the chemical solution supply unit 138 are housed within the chamber 110.

[0038] The processing liquid supply unit 132 supplies 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 evaporates, forming a packed layer from the solute. The packed layer is a solid film made up of the solute component. The packed layer can hold particles remaining in the recesses of the substrate W. When the packed layer is formed, particles that were attached to the upper surface Wa of the substrate W are pulled away from the substrate W and held in the packed layer.

[0039] Here, "solidification" refers to the process where a solute solidifies due to forces acting between molecules or atoms, for example, as the solvent evaporates. "Hardening" refers to the process where a solute solidifies due to chemical changes such as polymerization or crosslinking. Therefore, "solidification or hardening" means that the solute "solidifies" due to various factors. The processing solution only needs to solidify or harden to the extent that it can hold the particles; the solvent does not need to evaporate completely. Furthermore, the "solute components" that form the packed bed may be the solute itself contained in the processing solution, or they may be derived from the solute, for example, obtained as a result of chemical changes.

[0040] Various resins can be used as the solute, which are soluble in any solvent and, during solidification or curing, can form a packed layer while separating and retaining particles that were attached to the upper surface of the substrate W from the substrate W. For example, a resin that is sparingly soluble or insoluble in water before being heated above a predetermined alteration temperature, and which becomes water-soluble when heated above the alteration temperature (hereinafter sometimes referred to as a "heat-sensitive water-soluble resin") may be used as the solute.

[0041] As a heat-sensitive water-soluble resin, for example, a resin that decomposes when heated above a predetermined alteration temperature (e.g., 200°C or higher), exposing polar functional groups and exhibiting water solubility, can be used. When a heat-sensitive water-soluble resin is heated above its alteration temperature, it changes to a water-soluble state.

[0042] However, the temperature of the heat-sensitive water-soluble resin may be intentionally kept below its degradation temperature to form a packed layer while maintaining its sparing or insoluble nature in aqueous liquids. By setting the temperature of the processing liquid below the degradation temperature of the heat-sensitive water-soluble resin when forming the packed layer, a packed layer that is sparingly soluble or insoluble in aqueous liquids is formed on the upper surface of the substrate W without altering the heat-sensitive water-soluble resin to water-soluble form. In this case, the packed layer can be removed from the substrate W while maintaining its aggregate state without the particles falling out of the packed layer. Therefore, particles can be removed with a high removal rate.

[0043] In addition to heat-sensitive water-soluble resins, other solutes that can be used in the processing solution include, 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, polyamide imide, etc.

[0044] The solvent is preferably one that has higher volatility than water. It is preferable to use PGEE (propylene glycol monoethyl ether) as the solvent.

[0045] Furthermore, the processing solution may contain a sublimable substance. Various substances can be used as sublimable substances that have a high vapor pressure at 5°C to 35°C and change from the solid phase to the gas phase without passing through the liquid phase. Examples of sublimable substances include hexamethylenetetramine, 1,3,5-trioxane, ammonium 1-pyrrolidinecarbodithioate, metaldehyde, paraffin with approximately 20 to 48 carbon atoms, t-butanol, paradichlorobenzene, naphthalene, L-menthol, and fluorinated hydrocarbon compounds. In particular, fluorinated hydrocarbon compounds can be used as sublimable substances.

[0046] As the fluorinated hydrocarbon compound, for example, one or more of the following compounds (A) to (E) can be used.

[0047] Compound (A): Fluoroalkanes with 3 to 6 carbon atoms, or their derivatives. Compound (B): Fluorocycloalkanes with 3 to 6 carbon atoms, or their derivatives. Compound (C): A fluorobicycloalkane having 10 carbon atoms, or a derivative thereof. Compound (D): Fluorotetracyanoquinodimethane or its derivatives Compound (E): Fluorocyclotriphosphazene or its derivatives

[0048] Compound (A) may include fluoroalkanes having 3 to 6 carbon atoms, represented by formula (1), or their derivatives.

[0049] C m H n F2 m+2-n (1) [In the formula, m represents a number between 3 and 6, and n represents a number between 0 and 2m+1.]

[0050] It is particularly preferable to use 1,1,2,2,3,3,4-heptafluorocyclopentane as the sublimable substance. This compound has a vapor pressure of approximately 8266 Pa at 20°C, a melting point (freezing point) of 20.5°C, and a boiling point of 82.5°C. When mixing a sublimable substance in a molten state, a solvent that is compatible with the sublimable substance in a molten state is preferred as the solvent. Furthermore, when dissolving a sublimable substance as a solute, a solvent that is soluble in that sublimable substance is preferred.

[0051] Furthermore, when mixing a sublimable substance in a molten state, a solvent that is compatible with the sublimable substance in a molten state is preferred as the solvent. Also, when dissolving a sublimable substance as a solute, a solvent that is soluble in the sublimable substance is preferred.

[0052] Examples of solvents include at least one selected from the group consisting of DIW, pure water, aliphatic hydrocarbons, aromatic hydrocarbons, esters, alcohols, ethers, and the like. Specifically, examples include at least one selected from the group consisting of DIW, pure water, methanol, ethanol, IPA, 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 m-xylene hexafluoride.

[0053] The processing liquid supply unit 132 includes a pipe 132a, a valve 132b, and a nozzle 132n. The nozzle 132n discharges the processing liquid onto the upper surface Wa of the substrate W. The nozzle 132n is connected to the pipe 132a. The processing liquid is supplied to the pipe 132a from a supply source. The valve 132b opens and closes the flow path within the pipe 132a. It is preferable that the nozzle 132n is configured to be movable relative to the substrate W.

[0054] The removal liquid supply unit 134 supplies the removal liquid to the upper surface Wa of the substrate W. The removal liquid can remove the packed layer formed from the solute of the processing liquid. By controlling the time the removal liquid is supplied, the packed layer can be selectively removed from the substrate W.

[0055] Any solvent that is soluble in any of the resins can be used as the removal solution. For example, organic solvents such as paint thinner, toluene, acetic acid esters, alcohols, and glycols, or acidic solutions such as acetic acid, formic acid, and hydroxyacetic acid can be used as the removal solution. In particular, it is preferable to use a solvent that is compatible with aqueous liquids. For example, it is preferable to use isopropyl alcohol (IPA) as the removal solution.

[0056] The removal liquid supply unit 134 includes a pipe 134a, a valve 134b, and a nozzle 134n. The nozzle 134n discharges 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 to the pipe 134a from a supply source. The valve 134b opens and closes the flow path in the pipe 134a. It is preferable that the nozzle 134n is configured to be movable relative to the substrate W.

[0057] The water-repellent supply unit 136 supplies a liquid water-repellent agent to the upper surface Wa of the substrate W. The supply of the water-repellent agent forms a water-repellent layer on the upper surface Wa of the substrate W.

[0058] For example, the water repellent contains a compound with a methyl or silyl group at its terminal end. Typically, hydroxyl groups (OH groups) are present on the surface of the recess, but the water repellent replaces the hydroxyl groups on the surface of the substrate W with methyl or silyl groups. It is preferable that the water repellent does not alter the properties of the packing layer.

[0059] For example, water repellents are those that hydrophobicize silicon (Si) itself and silicon-containing compounds. Typically, water repellents are silane coupling agents. In one example, a silane coupling agent includes at least one of HMDS (hexamethyldisilazane), TMS (tetramethylsilane), fluorinated alkylchlorosilane, alkyldisilazane, and non-chloro water repellents. Non-chloro water repellents include, for example, at least one of dimethylsilyldimethylamine, dimethylsilyldiethylamine, hexamethyldisilazane, tetramethyldisilazane, bis(dimethylamino)dimethylsilane, N,N-dimethylaminotrimethylsilane, N-(trimethylsilyl)dimethylamine, and organosilane compounds.

[0060] The water-repellent supply unit 136 includes a pipe 136a, a valve 136b, and a nozzle 136n. The nozzle 136n discharges 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 to the pipe 136a from a supply source. The valve 136b opens and closes the flow path in the pipe 136a. It is preferable that the nozzle 136n is configured to be movable relative to the substrate W.

[0061] The chemical supply unit 138 supplies a chemical solution to the upper surface Wa of the substrate W. The upper surface Wa of the substrate W can be treated with the chemical solution. Through chemical treatment, it is possible to perform any of the following on the substrate W: etching, surface treatment, property imparting, formation of a treated film, and removal of at least a portion of the film. Typically, the chemical solution is an etching solution used for etching the substrate W.

[0062] The chemical solution contains hydrofluoric acid. For example, hydrofluoric acid may be heated to a temperature between 40°C and 70°C, or between 50°C and 60°C. However, hydrofluoric acid does not need to be heated. The chemical solution may also contain water or phosphoric acid.

[0063] Furthermore, the chemical solution may also contain hydrogen peroxide. 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).

[0064] The chemical supply unit 138 includes a pipe 138a, a valve 138b, and a nozzle 138n. The nozzle 138n discharges the chemical onto the upper surface Wa of the substrate W. The nozzle 138n is connected to the pipe 138a. The chemical is supplied to the pipe 138a from a supply source. The valve 138b opens and closes the flow path in the pipe 138a. It is preferable that the nozzle 138n is configured to be movable relative to the substrate W.

[0065] 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 may be movable. The nozzles 132n, 134n, 136n, and 138n can move horizontally and / or vertically according to a movement mechanism controlled by the control unit 102. Note that in this specification, the movement mechanism has been omitted to avoid making the drawings excessively complex.

[0066] The substrate processing apparatus 100 further includes a cup 180. The cup 180 collects liquid splashed from the substrate W. The cup 180 moves up and down. For example, the cup 180 rises vertically upward to the side of the substrate W during the period when the liquid supply unit 130 supplies liquid to the substrate W. In this case, the cup 180 collects liquid splashed from the substrate W due to the rotation of the substrate W. The cup 180 then descends vertically downward from the side of the substrate W when the period during which the liquid supply unit 130 supplies liquid to the substrate W ends.

[0067] 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 cup 180. In one example, the control unit 102 controls the electric motor 124, and valves 132b, 134b, 136b, and / or 138b.

[0068] The substrate processing apparatus 100 of this embodiment is suitably used for manufacturing semiconductor devices on which semiconductors are provided. Typically, in a semiconductor device, a conductive layer and an insulating layer are laminated on a substrate. The substrate processing apparatus 100 is suitably used for cleaning and / or processing (e.g., etching, property change, etc.) the conductive layer and / or insulating layer during the manufacturing of semiconductor devices.

[0069] Next, the substrate processing apparatus 100 of this embodiment will be described with reference to Figures 1 to 3. Figure 3 is a block diagram of the substrate processing apparatus 100.

[0070] As shown in Figure 3, the control device 101 controls various operations of the substrate processing apparatus 100. The control device 101 controls the indexer robot IR, the center robot CR, the substrate holding unit 120, and the liquid supply unit 130. Specifically, the control device 101 controls the indexer robot IR, the center robot CR, the substrate holding unit 120, and the liquid supply unit 130 by transmitting control signals to them.

[0071] Specifically, the control unit 102 controls the indexer robot IR to transfer the substrate W using the indexer robot IR.

[0072] The control unit 102 controls the center robot CR to transfer the substrates W. For example, the center robot CR receives an unprocessed substrate W and loads it into one of the multiple chambers 110. The center robot CR also receives the processed substrates W from the chamber 110 and unloads them.

[0073] The control unit 102 controls the substrate holder 120 to control the start of rotation of the substrate W, the change in rotation speed, and the stop of rotation of the substrate W. For example, the control unit 102 can change the rotation speed of the substrate holder 120 by controlling the substrate holder 120. Specifically, the control unit 102 can change the rotation speed of the substrate W by changing the rotation speed of the electric motor 124 of the substrate holder 120.

[0074] The control unit 102 can individually control the valves 132b, 134b, 136b, and 138b of the liquid supply unit 130, switching the state of valves 132b, 134b, 136b, and 138b between open and closed states. Specifically, the control unit 102 controls the valves 132b, 134b, 136b, and 138b of the liquid supply unit 130 to open them, thereby allowing the processing liquid, removal liquid, water repellent, and chemical solution flowing through the pipes 132a, 134a, 136a, and 138a to pass towards the nozzles 132n, 134n, 136n, and 138n. Furthermore, the control unit 102 can control the valves 132b, 134b, 136b, and 138b of the liquid supply unit 130 to close the valves 132b, 134b, 136b, and 138b, thereby stopping the supply of the treatment liquid, removal liquid, water repellent, and chemical solution flowing through the pipes 132a, 134a, 136a, and 138a toward the nozzles 132n, 134n, 136n, and 138n, respectively.

[0075] The substrate processing apparatus 100 of this embodiment is suitably used for forming semiconductor elements. For example, the substrate processing apparatus 100 is suitably used for processing a substrate W used as a multilayer semiconductor element. The semiconductor element is a so-called 3D memory (storage device). As an example, the substrate W is suitably used as a NAND flash memory.

[0076] Next, with reference to Figure 4, a substrate W fabricated as a semiconductor element 300 using the substrate processing apparatus 100 of this embodiment will be described. Figure 4(a) is a schematic side view of a semiconductor element 300 fabricated by processing the substrate W using the substrate processing apparatus 100, Figure 4(b) is a schematic top view of the semiconductor element 300, and Figure 4(c) is a partially enlarged view of Figure 4(b). In Figure 4, the direction perpendicular to the main surface of the substrate S of the substrate W is shown as the z direction, and the directions perpendicular to the z direction are shown as the x direction and y direction.

[0077] As shown in Figure 4(a), the substrate W has a base material S and a laminated structure L. The base material S is a thin film extending in the xy plane. The laminated structure L is formed on the upper surface of the base material S. The base material S supports the laminated structure L. The laminated structure L is formed to extend in the z direction from the upper surface of the base material S.

[0078] Furthermore, the substrate W shown in Figure 4(a) preferably has an etching stop layer Es between the base material S and the laminated structure L. The etching stop layer Es is formed from, for example, alumina (Al2O3). As will be described in detail later, a recess R is formed when the laminated structure L is partially removed by etching. In the example in Figure 4, the recess R is a memory hole. The progress of etching is stopped by the etching stop layer Es.

[0079] The laminated structure L comprises an insulating layer N and a conductive layer M. The insulating layer N and the conductive layer M are stacked alternately. For example, the insulating layer N is formed from a silicon oxide film. The conductive layer M is formed from a metal. For example, the conductive layer M contains tungsten (W).

[0080] Each of the multiple insulating layers N extends parallel to the upper surface of the substrate S. A conductive layer M is provided between two adjacent insulating layers N. The two adjacent insulating layers N are supported by the conductive layer M.

[0081] For example, the thickness of the insulating layer N (length along the z-direction) is between 1 nm and 50 nm. Also, for example, the thickness of the conductive layer M (length along the z-direction) is between 1 nm and 50 nm.

[0082] The sum of the thickness of one insulating layer N and one conductive layer M is between 20 nm and 100 nm. The laminated structure L comprises 10 to 100 insulating layers N and 10 to 100 conductive layers M.

[0083] A recess R is provided in the laminated structure L. The recess R extends in a direction perpendicular to the main surface of the substrate S. The recess R extends between the surface La of the laminated structure L and the etching stop layer Es. The length of the recess R in a direction perpendicular to the direction in which the recess R extends is defined as the "width of the recess R". The "diameter of the recess R" is an example of the "width of the recess R".

[0084] The diameter of recess R is on the nanoscale. For example, the diameter of recess R is between 20 nm and 300 nm. The diameter of recess R may also be between 50 nm and 200 nm.

[0085] Ideally, the recess R is formed perpendicular to the main surface of the substrate S. The diameter of the surface portion of the recess R (top diameter Wt) is between 20 nm and 300 nm, and between 50 nm and 200 nm.

[0086] For example, the aspect ratio of recess R is 10 or greater. The aspect ratio represents the ratio of the height to the width of recess R. To date, it has been reported that memory holes with a height of approximately 1 μm can be formed with an aspect ratio of 40 to 50, and it is expected that the aspect ratio will increase further in the future. For example, the upper limit of the aspect ratio of recess R may be 100 or 200.

[0087] In the semiconductor device 300 shown in Figure 4(a), a cylindrical charge-holding layer H is arranged within a recess R in the substrate W. Inside the charge-holding layer H, a cylindrical channel layer Ch is arranged. For example, the channel layer Ch is formed from polysilicon. Inside the channel layer Ch, a cylindrical dielectric layer D is arranged. The dielectric layer D is formed from a silicon oxide film.

[0088] The charge-holding layer H may 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 laminated structure L. The intermediate layer H2 is located inside the outer layer H3. The inner layer H1 is located inside the intermediate layer H2. The inner layer H1 is in contact with the channel layer Ch. Thus, the dielectric layer D, channel layer Ch, inner layer H1, intermediate layer H2, and outer layer H3 are arranged from the center of the recess R of the laminated structure L.

[0089] For example, the inner layer H1 is formed from a silicon oxide film. The inner layer H1 is also called the tunnel layer.

[0090] For example, the intermediate layer H2 is formed from a silicon nitride film. The intermediate layer H2 stores electric charge. The intermediate layer H2 is also called the charge storage layer.

[0091] For example, the outer layer H3 is formed from a silicon oxide film. The outer layer H3 is also called the block layer.

[0092] When a voltage is applied to the conductive layer M and the channel layer Ch, charge is accumulated in the corresponding intermediate layer H2. As shown in Figure 4(a), memory elements Se are formed corresponding to the conductive layer M. Therefore, a number of memory elements Se corresponding to the number of conductive layers M are formed within a single recess R.

[0093] As shown in Figure 4(b), multiple recesses R are formed in the substrate W, and the recesses R are regularly arranged in the substrate W. A charge retention layer H, a channel layer Ch, and a dielectric layer D are arranged within each recess R. The multiple recesses R are designed to have similar diameters and heights. For example, the difference in the top diameter Wt of each recess R may be 5% or less, or 3% or less.

[0094] Typically, recesses R are formed by dry etching the laminated structure L. When forming recesses R by dry etching the laminated structure L, the diameter of the deeper part of the recess R may be smaller than the diameter of the surface side of the recess R. In particular, as the height of the laminated structure L and / or the number of layers of the laminated structure L increases, the diameter of the deeper part of the recess R tends to become smaller than the diameter of the surface side of the recess R. Also, the shorter the dry etching processing period to improve throughput, the more likely the diameter of the deeper part of the recess R is to become smaller than the diameter of the surface side of the recess R.

[0095] As shown in Figure 4(a), multiple memory elements Se are formed within the recess R. For this reason, it is preferable that the diameter of the recess R be constant from the surface to the depth. However, when forming a recess R in a stacked structure L, the diameter of the recess R may not be constant. If the diameter of the recess R is different, forming memory elements within the recess R may result in inconsistent electrical characteristics of the memory elements, making it impossible to uniformize the characteristics of the memory elements.

[0096] Furthermore, generally speaking, the smaller the diameter of the recess R, the more memory elements can be formed on the substrate S. Therefore, to increase memory capacity, it is preferable to have a small recess R diameter. However, if the diameter of the recess R is small, the flow of the etching fluid for etching the recess R tends to be insufficient. For this reason, when etching the recess R, etching tends to be uneven depending on the location of the recess R. Specifically, the surface portion of the recess R is relatively easy to etch, while the deeper part of the recess R is relatively difficult to etch.

[0097] As will be explained in detail later, according to this embodiment, even if the diameter of the recess R is small, the deep part of the recess R (hereinafter referred to as "deep recess Rf") can be selectively etched. This suppresses the non-uniformity of the diameter of the recess R.

[0098] Next, the semiconductor device formation method of this embodiment will be described with reference to Figure 5. Part of the semiconductor device formation method of this embodiment is performed using the substrate processing apparatus 100 described above with reference to Figures 1 to 3.

[0099] As shown in Figure 5(a), the substrate W has a base material S and a laminated structure L. The base material S is a thin film extending in the xy plane. The laminated structure L is formed on the upper surface of the base material S. The laminated structure L is formed to extend in the z direction from the upper surface of the base material S. For example, the laminated structure L is formed from a silicon oxide film (SiO2) and a silicon nitride film (SiN). The laminated structure L has a surface La.

[0100] The laminated structure L comprises an insulating layer N and a sacrificial layer Sa. The insulating layers N and the sacrificial layer Sa are stacked alternately. Each of the multiple insulating layers N extends parallel to the upper surface of the substrate S. A sacrificial layer Sa is provided between two adjacent insulating layers N. Two adjacent insulating layers N are supported by the sacrificial layer Sa. Note that the sacrificial layer Sa is replaced with the conductive layer M shown in Figure 4 during the process of fabricating the semiconductor device 300.

[0101] For example, the thickness (length along the z-direction) of the insulating layer N is between 1 nm and 50 nm. The insulating layer N is formed from a silicon oxide film.

[0102] Furthermore, for example, the thickness of the sacrificial layer Sa (length along the z-direction) is between 1 nm and 50 nm. In one example, the sacrificial layer Sa is formed from a silicon nitride film.

[0103] As shown in Figure 5(b), a recess R is formed in the laminated structure L. Typically, the recess R is formed by dry etching. Ideally, the diameter (length in the xy plane) of the recess R formed by dry etching should be constant from the surface to the depth, but in reality, the diameter of the recess R may not be constant from the surface to the depth. In particular, when the dry etching processing time is shortened to improve the throughput of the substrate W, it is difficult for the diameter of the recess R to be constant from the surface to the depth. In this case, the diameter of the deep recess Rf will be smaller than the diameter of the surface portion Rn of the recess R.

[0104] For example, the deep recess Rf refers to the portion of the recess R located on the substrate S side. The surface-side portion Rn refers to the portion of the recess R located on the surface side.

[0105] As shown in Figure 5(c), the recess R of the substrate W is deformed. For example, the diameter of the deep recess Rf is selectively made larger than the diameter of the deep recess Rf after dry etching. In one example, the diameter of the deep recess Rf is widened over a length of less than 10 nm along the xy plane. This makes the diameter of the recess R of the substrate W uniform from the surface to the depth.

[0106] As shown in Figure 5(d), a charge-retaining layer H is formed inside the recess R of the laminated structure L.

[0107] As shown in Figure 5(e), a channel layer Ch and a dielectric layer D are formed inside the charge-holding layer H. Then, the sacrificial layer Sa is replaced with a conductive layer M. In this way, the semiconductor device 300 shown in Figure 4 can be formed.

[0108] Note that in Figure 5(b), the diameter of recess R is shown to change linearly from the surface to the depth in order to avoid overly complex explanations, but this embodiment is not limited to this. Due to the bowing effect, the diameter of recess R may be largest near the center.

[0109] Next, a general semiconductor device fabrication method will be explained with reference to Figure 6. Figures 6(a) to 6(g) are schematic diagrams illustrating a general semiconductor device fabrication method.

[0110] As shown in Figure 6(a), a recess R is provided in the laminated structure L of the substrate W. As shown in Figure 6(b), a packing layer F is filled into the recess R. As shown in Figure 6(c), a removal liquid Ds is applied to the substrate W. The removal liquid Ds partially dissolves the packing layer F filled into the recess R. As a result, a partial packing layer Fp is formed from the packing layer F, partially filling the deep part Rf of the recess. As shown in Figure 6(d), a water repellent P is supplied to the substrate W. The removal liquid Ds is then replaced by the water repellent P. Since the surface-side portion Rn of the recess R is not covered by the partial packing layer Fp, the surface of the laminated structure L and the water repellent P react in the surface-side portion Rn of the recess R to form a coating film Ps.

[0111] As shown in Figure 6(e), the partial packing layer Fp and water repellent P are removed. As shown in Figure 6(f), the recess R is etched with chemical C. The deep recess Rf is etched by chemical C because the insulating layer N and sacrificial layer Sa are exposed. As a result, as shown in Figure 6(f), the region Re located in the deep recess Rf is removed by chemical C, and the diameter of the recess R expands. As shown in Figure 6(g), the chemical C and coating film Ps are removed.

[0112] Next, the surface state of the laminated structure L will be explained with reference to Figures 7 and 8. Figures 7(a) to 7(c) are schematic diagrams illustrating the surface state of the silicon oxide film as the insulating layer N (Figure 6) in the comparative example.

[0113] As shown in Figure 7(a), multiple adsorption sites 10 exist on the surface of the insulating layer N. Each of the multiple adsorption sites 10 contains a hydroxyl group. The adsorption sites represent regions on the solid surface acting as the adsorbent that adsorb molecules as the adsorbate.

[0114] As shown in Figure 7(b), when a water repellent P (Figure 6(d)) is supplied to the surface of the insulating layer N, the water repellent P reacts with the hydroxyl groups of the adsorption sites 10 to form a coating film Ps (Figure 6(d)). Specifically, the hydroxyl groups of the adsorption sites 10 are replaced by methyl or silyl groups of the water repellent P, causing the molecules PsM, which are the material for the coating film Ps, to be adsorbed onto the surface of the insulating layer N. As a result, the coating film Ps is formed on the insulating layer N.

[0115] As shown in Figure 7(c), even when chemical solution C is supplied (Figure 6(f)), the insulating layer N is not etched because a coating film Ps is formed on the insulating layer N. In other words, the coating film Ps protects the insulating layer N from chemical solution C. To put it another way, the coating film Ps functions as a protective film.

[0116] Figures 8(a) to 8(c) are schematic diagrams illustrating the surface state of the silicon nitride film as the sacrificial layer Sa (Figure 6) in the comparative example.

[0117] As shown in Figure 8(a), multiple adsorption sites 11 exist on the surface of the sacrificial layer Sa. Each of the multiple 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 the number of adsorption sites 11 per unit area on the surface of the insulating layer N shown in Figure 7(a). This is because the sacrificial layer Sa is a silicon nitride film.

[0118] As shown in Figure 8(b), when a water repellent P (Figure 6(d)) is supplied to the surface of the sacrificial layer Sa, the water repellent P reacts with the hydroxyl groups at the adsorption sites 10 to form a coating film Ps (Figure 6(d)). Specifically, the hydroxyl groups at the adsorption sites 11 are replaced by methyl or silyl groups of the water repellent P, causing the molecules PsM, which are the material for the coating film Ps, to be adsorbed onto the surface of the sacrificial layer Sa. As a result, the coating film Ps is formed on the sacrificial layer Sa.

[0119] However, because the number of adsorption sites 10 on the surface of the sacrificial layer Sa is small (Figure 8(a)), the coating film Ps on the sacrificial layer Sa may have a larger number of non-adsorbed regions 20 where the molecules PsM of the coating film Ps are not adsorbed, compared to the coating film Ps on the insulating layer N (Figure 7(b)). A large number of non-adsorbed regions 20 indicates that the protective function of the coating film Ps is reduced.

[0120] As shown in Figure 8(c), when chemical solution C is supplied (Figure 6(f)), there are many non-adsorbent regions 20 on the coating film Ps on the sacrificial layer Sa. Therefore, etching by chemical solution C may proceed in the parts of the sacrificial layer Sa corresponding to the non-adsorbent regions 20. In this case, the protective function of the coating film Ps on the sacrificial layer Sa is reduced.

[0121] Here, as shown in Figure 6(d), by supplying a water-repellent agent P to the recess R, a coating film Ps is simultaneously formed on the insulating layer N and the sacrificial layer Sa. Therefore, as can be understood from Figures 7 and 8, the insulating layer N of the surface portion Rn of the recess R is not affected by etching with the chemical solution C because the protective function of the coating film Ps is not reduced. On the other hand, the sacrificial layer Sa of the surface portion Rn of the recess R is affected by etching with the chemical solution C because the protective function of the coating film Ps is reduced. In other words, etching with the chemical solution C may occur on the sacrificial layer Sa in the portion of the recess R where it is not necessary to widen the diameter (surface portion Rn).

[0122] Therefore, in the semiconductor device formation method according to this embodiment, a first coating film Ps1 (Figure 9(b)) with a large number of adsorption sites is formed before forming the second coating film Ps2 (Figure 11(a)) which corresponds to the coating film Ps.

[0123] Next, the semiconductor device formation method according to this embodiment will be described with reference to Figures 9 to 13. Figures 9 to 13 are schematic diagrams for illustrating the semiconductor device formation method according to this embodiment. The semiconductor device formation method shown in Figures 9 to 13 is suitably used as part of the semiconductor device formation method described above with reference to Figure 5. For example, the semiconductor device formation method shown in Figures 9 to 13 is performed using a variation of the recess R shown in Figure 5(c). The semiconductor device formation method of this embodiment is performed using the substrate processing apparatus 100 described above with reference to Figures 1 to 3.

[0124] First, as shown in Figure 9(a), recesses R are provided in the laminated structure L. For example, recesses R are formed in the laminated structure L by etching the substrate W. Here, recesses R are formed in the insulating layer N and the sacrificial layer Sa. The recesses R reach 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.

[0125] Next, as shown in Figure 9(b), a first coating film Ps1 is formed extending from the recess depth Rf to the surface portion Rn. Typically, the first coating film Ps1 is a silicon oxide film. The thickness of the first coating film Ps1 (length along the x-direction) is, for example, between 0.1 nm and 10 nm.

[0126] Typically, the first coating film Ps1 is formed in the recess R by the ALD (Atomic Layer Deposition) method. The ALD method is a film formation method that deposits atomic layers one by one by repeatedly supplying and purging gas-phase raw materials (precursors). The ALD method utilizes the self-regulating properties of atoms. According to the ALD method, the first coating film Ps1 can be formed with high precision and uniformity. The ALD apparatus (not shown) forms the first coating film Ps1 by the ALD method.

[0127] The method for forming the first coating film Ps1 is not particularly limited. For example, the first coating film Ps1 may be formed by supplying ozonated water, hydrogen peroxide solution, or a sulfuric acid / hydrogen peroxide mixture (SPM) to the recess R.

[0128] Next, as shown in Figure 10(a), a packing layer F is filled into the recess R so as to cover the first coating film Ps1. The packing layer F is, for example, an organic material (carbon-based material). In one example, the packing layer F is a polymer. The packing layer F may also be formed from a resist. For example, after the processing liquid supply unit 132 supplies the processing liquid to the substrate W, the solvent is evaporated from the processing liquid, and the packing layer F is formed from the solute of the processing liquid. Here, the packing layer F is filled from the deep recess Rf to the surface portion Rn so as to cover the first coating film Ps1.

[0129] It is preferable that the processing solution changes into a solid state after being applied to the substrate W. Although the processing solution itself is in a liquid state, the solvent evaporates after the processing solution is applied to the substrate W, causing the solute to change into a solid state and form a packed layer F.

[0130] Next, as shown in Figure 10(b), the removal solution Ds is applied to the substrate W. The removal solution Ds dissolves the packed layer F. Here, the removal solution Ds partially dissolves the packed layer F that has filled the recess R. As a result, the packed layer F remains filled in the deep recess Rf, while the surface portion Rn of the recess R is replaced by the removal solution Ds. Consequently, a partial packed layer Fp is formed from the packed layer F, partially filling the deep recess Rf. Note that the removal solution Ds does not dissolve the first coating film Ps1.

[0131] For example, the removal solution supply unit 134 supplies the removal solution Ds to the substrate W. The removal solution supply unit 134 supplies the removal solution Ds for a time and in an amount set so that the packed layer F is partially dissolved without being completely dissolved. For example, the removal solution Ds contains isopropyl alcohol (IPA).

[0132] Typically, more than half of the depth of recess R is replaced by the removal solution Ds, leaving less than half of the packed bed F within the depth of recess R, forming a partial packed bed Fp. For example, the depth of the partial packed bed Fp (length in the z-axis direction) is less than or equal to 1 / 3 of the depth of recess R.

[0133] Next, as shown in Figure 11(a), a water-repellent agent P is supplied. For example, the water-repellent agent supply unit 136 supplies the water-repellent agent P to the substrate W. The partial filling layer Fp is not affected by the water-repellent agent P, and the removal liquid Ds is replaced by the water-repellent agent P. As a result, the partial filling layer Fp remains filled in the deep recess Rf, while the removal liquid Ds in the surface portion Rn of the recess R is replaced by the water-repellent agent P.

[0134] Furthermore, while the deep recess Rf is covered with a partially packed layer Fp, the surface portion Rn of the recess R is not covered with the partially packed layer Fp. Therefore, when a water repellent P is supplied, the surface of the first coating film Ps1 reacts with the water repellent P in the surface portion Rn of the recess R, forming a second coating film Ps2 on the first coating film Ps1. The second coating film Ps2 is composed of, for example, a molecular film of an organic silane compound produced 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-chloro water repellent. Non-chlorohydrophobic agents include, for example, dimethylsilyldimethylamine, dimethylsilyldiethylamine, hexamethyldisilazane, tetramethyldisilazane, bis(dimethylamino)dimethylsilane, N,N-dimethylaminotrimethylsilane, N-(trimethylsilyl)dimethylamine, and at least one organosilane compound. The thickness (length along the x-direction) of the second coating film Ps2 is, for example, 0.5 nm to 5 nm. Since the first coating film Ps1 is the base layer for the second coating film Ps2, the first coating film Ps1 can also be called the base layer.

[0135] The deep recess Rf is the portion of recess R that is not covered by the second coating film Ps2. In other words, the deep recess Rf is the portion of recess R that is located closer to the substrate S than the second coating film Ps2. To put it another way, the deep recess Rf is the portion of recess R that is located deeper than the second coating film Ps2.

[0136] Next, as shown in Figure 11(b), the partial packing layer Fp and the water repellent P are removed. In this case, a portion of the water repellent P on the surface side of the recess R is removed along with the partial packing layer Fp in the deep recess Rf. At this time, it is preferable that particles, which are residues from when the recess R was formed (for example, during dry etching), are also removed. By removing the partial packing layer Fp, the first coating film Ps1 is exposed in the deep recess Rf. On the other hand, the surface side portion Rn of the recess R remains covered with the second coating film Ps2. The second coating film Ps2 covers the first coating film Ps1.

[0137] For example, a removal solution may be applied to remove the partial packing layer Fp and the water repellent P. In one example, the removal solution includes IPA. For example, the removal solution supply unit 134 supplies the removal solution Ds to the substrate W. The removal solution supply unit 134 supplies the removal solution for a time and in an amount set to completely dissolve the partial packing layer Fp.

[0138] Alternatively, the substrate W may be heated to remove the partial packing layer Fp and the water repellent P. For example, if the partial packing layer Fp is formed from a sublimable material, heating may cause the partial packing layer Fp to sublimate.

[0139] Next, as shown in Figure 12(a), the recess R is etched with the first chemical solution C1. Typically, the first chemical solution C1 contains hydrofluoric acid. For example, the first chemical solution C1 contains hydrofluoric acid (dilute hydrofluoric acid) diluted in the range of 1:100 to 1:2000. For example, the hydrofluoric acid may be heated to 40°C to 70°C, or to 50°C to 60°C. Alternatively, the first chemical solution C1 may contain water or deionized water (DIW). Alternatively, the first chemical solution C1 may contain phosphoric acid. Alternatively, the first chemical solution C1 may be fluoride-containing phosphoric acid. Fluoride-containing phosphoric acid is phosphoric acid containing fluoride. In this case, the fluoride is ammonium fluoride or ammonium hydrogen difluoride.

[0140] In the deep recess Rf, the first coating film Ps1 is exposed (Figure 11(b)), and therefore the first coating film Ps1 is etched by the first chemical solution C1. When the first coating film Ps1 in the deep recess Rf is etched, the insulating layer N and the sacrificial layer Sa are exposed. As a result, in the deep recess Rf, the insulating layer N and the sacrificial layer Sa are etched by the first chemical solution C1. In this case, the first chemical solution C1 is a liquid that etches the insulating layer N and the sacrificial layer Sa at a substantially constant rate. Therefore, the deep recess Rf is etched by the first chemical solution C1 at a substantially constant rate. Note that in Figure 12(a), the diameter of the deep recess Rf after etching is made substantially the same in order to avoid making the drawing complicated. Alternatively, only the first coating film Ps1 may be etched by the first chemical solution C1 in the deep recess Rf. In this case, the entire first coating film Ps1 may be etched, or only a part of the first coating film Ps1 may be etched.

[0141] On the other hand, the surface portion Rn of recess R is covered by the second coating film Ps2 and is therefore not etched by the first chemical solution C1. As a result, as shown in Figure 12(a), the region Re1 located in the deep recess Rf is removed by the first chemical solution C1, and the diameter of recess R expands.

[0142] In this case, for example, if the goal is to ultimately widen the diameter of the recess depth Rf by U [nm], the diameter of the recess depth Rf is widened by V [nm]. V [nm] is smaller than U [nm]. The reason for widening the diameter of the recess depth Rf by V [nm] is that when the first coating film Ps1 is removed in a later step (Figure 13(a)), the insulating layer N and sacrificial layer Sa of the recess depth Rf are etched. The amount of etching by the first chemical solution C1 is adjusted, for example, by the etching time.

[0143] Furthermore, the first chemical solution C1 is either 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.

[0144] Next, as shown in Figure 12(b), the first chemical solution C1 and the second coating film Ps2 are removed. The first chemical solution C1 and the second coating film Ps2 may be removed by ultraviolet irradiation or heating. It is also preferable that any residue from dry etching is removed at this time. Alternatively, the first chemical solution C1 and the second coating film Ps2 may be removed by supplying SPM to the recess R.

[0145] Next, as shown in Figure 13(a), the first coating film Ps1 is removed with the second chemical solution C2. The second chemical solution C2 is, for example, the same as the first chemical solution C1 used in the step shown in Figure 12(a). That is, the second chemical solution C2 contains hydrofluoric acid. For example, the second chemical solution C2 contains hydrofluoric acid (dilute hydrofluoric acid) diluted in the range of 1:100 to 1:2000. For example, the hydrofluoric acid may be heated to 40°C to 70°C or 50°C to 60°C. Alternatively, the second chemical solution C2 may contain water or DIW. Alternatively, the second chemical solution C2 may contain phosphoric acid. Alternatively, the second chemical solution C2 may be fluoride-containing phosphoric acid. Fluoride-containing phosphoric acid is phosphoric acid containing fluoride. In this case, the fluoride is ammonium fluoride or ammonium hydrogen difluoride.

[0146] In the recess R, the first coating film Ps1 on the surface portion Rn is etched (removed) by the second chemical solution C2, and the insulating layer N and sacrificial layer Sa of the deep recess Rf are also etched by the second chemical solution C2. Consequently, the region Re2 located in the deep recess Rf is removed by the second chemical solution C2, and the diameter of the recess R expands further. The diameter of the deep recess Rf may expand to be equal to the diameter just before the recess R (top diameter).

[0147] In this case, the second chemical solution C2 is a liquid that etches the first coating film Ps1, the insulating layer N, and the sacrificial layer Sa at approximately a constant rate. Therefore, in the recess R, the first coating film Ps1 on the surface portion Rn, and the insulating layer N and sacrificial layer Sa in the deep recess Rf are etched by the second chemical solution C2 at approximately a constant rate. Note that in Figure 13(a), the diameter of the deep recess Rf after etching is made approximately the same to avoid making the drawing complicated. Also, if the first coating film Ps1 remains in the deep recess Rf, the first coating film Ps1, the insulating layer N, and the sacrificial layer Sa are etched by the second chemical solution C2.

[0148] Here, for example, if the goal is to ultimately widen the diameter of the recess depth Rf by U [nm], then in the process shown in Figure 12(a), the diameter of the recess depth Rf is widened by V [nm]. V [nm] is smaller than U [nm]. Therefore, in the process shown in Figure 13(a), etching is performed with the second chemical solution C2 so that, for example, the diameter of the recess depth Rf is widened by (UV) [nm]. The amount of etching by the second chemical solution C2 is adjusted, for example, by the etching time.

[0149] Next, as shown in Figure 13(b), the second chemical solution C2 is removed from recess R.

[0150] As described above, the diameter of the recess R in the laminated structure L can be adjusted. Note that in Figure 13, the diameter of the deep recess Rf is shown to be equal to the top diameter (opening) of the recess R, while the diameter of the deep recess Rf is larger than the diameter of the central part of the recess R, in order to easily understand the change in the shape of the recess R. However, this is merely an example. The diameter of the deep recess Rf may be widened so that the diameter of the deep recess Rf is equal to the diameter of the central part of the recess R. Alternatively, the recess R may be deformed so that the diameter of the deep recess Rf is equal to the diameter of the top diameter and the central part of the recess R. The same applies to Figure 12.

[0151] In Figure 10(b), by applying the removal liquid Ds, the packed bed F is partially replaced by the removal liquid Ds. When the diameter of the recess R is small, it takes a relatively long time for the removal liquid Ds to remove the entire packed bed F. Therefore, by interrupting the removal process of the packed bed F by the removal liquid Ds during the time it takes for the removal liquid Ds to remove the entire packed bed F, the packed bed F can be partially removed. Also, as shown in Figure 10(b), by adjusting the amount of removal liquid Ds and the processing time, it is possible to leave a partially packed bed Fp that covers the appropriate portion.

[0152] Furthermore, although a partial packed layer Fp is formed from the packed layer F using the removal liquid Ds in Figure 10(b), this embodiment is not limited to this. When the packed layer F is formed from a sublimable material, a partial packed layer Fp may be formed from the packed layer F by heating. In this case as well, by adjusting the heating time and temperature, a partial packed layer Fp that partially fills the recess depth Rf may be formed from the packed layer F.

[0153] Furthermore, it is preferable that the substrate W is used as a memory equipped with multiple memory elements Se. Typically, when the substrate W is used as a memory, the substrate W is provided with multiple recesses R designed to have a constant diameter and height. Therefore, multiple recesses R used in a memory with a large storage capacity can be deformed simultaneously by the same process.

[0154] Furthermore, when forming a recess R in the laminated structure L, the diameter of the recess R may be largest near the center due to the bowing phenomenon. In this case, it is preferable that the second coating film Ps2 covers the area near the center. In addition, the diameter of the deep recess Rf may be widened by etching so that it is equal to the diameter of the largest central part of the recess R.

[0155] In the above description with reference to Figure 11(a), the second coating film Ps2 was formed by supplying a liquid water-repellent agent P to the filled recess R of the partially packed layer Fp, but this embodiment is not limited to this. The second coating film Ps2 may also be formed by gas.

[0156] Next, with reference to Figure 14, the surface state of the first coating film Ps1 when forming the second coating film Ps2 will be explained. Figures 14(a) to 14(c) are schematic diagrams illustrating the surface state when forming the second coating film Ps2 on the first coating film Ps1. Figures 14(a) to 14(c) show the first coating film Ps1 on the sacrificial layer Sa (silicon nitride film) (Figure 9(b)). Note that the same first coating film Ps1 is also formed on the insulating layer N (silicon oxide film) as on the sacrificial layer Sa (Figure 9(b)).

[0157] As shown in Figure 14(a), multiple adsorption sites 12 exist on the surface of the first coating film Ps1. Each of the multiple 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 about the same as the number of adsorption sites 10 per unit area on the surface of the insulating layer N (Figure 7(a)). This is because, for example, the first coating film Ps1 and the insulating layer N are silicon oxide films. Furthermore, the number of adsorption sites 12 per unit area on the surface of the first coating film Ps1 is greater than the number of adsorption sites 11 per unit area on the surface of the sacrificial layer Sa (Figure 8(a)).

[0158] As shown in Figure 14(b), 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 of the adsorption sites 12 to form the second coating film Ps2 (Figure 11(a)). Specifically, the hydroxyl groups of the adsorption sites 12 are replaced by methyl or silyl groups of the water repellent P, causing the molecule PsM, which is the material for the second coating film Ps2, to be adsorbed onto the surface of the first coating film Ps1. As a result, the second coating film Ps2 is formed on the first coating film Ps1. In this case, because there are many adsorption sites 12 on the surface of the first coating film Ps1 (Figure 14(a)), the non-adsorbent region 20 (Figure 8(b)) in the second coating film Ps2 is extremely small compared to the coating film Ps of the comparative example (Figure 8(b)). Therefore, regardless of the sacrificial layer Sa and the insulating layer N, the protective function of the second coating film Ps2 is higher than that of the protective function of the coating film Ps of the comparative example (Figure 8(b)).

[0159] As shown in Figure 14(c), even when the first chemical solution C1 is supplied (Figure 12(a)), the sacrificial layer Sa is not etched because the second coating film Ps2 is formed. In other words, the second coating film Ps2 effectively protects the sacrificial layer Sa from the first chemical solution C1. To put it another way, the second coating film Ps2 functions effectively as a protective film. Specifically, because there are many adsorption sites 12 on the surface of the first coating film Ps1 (Figure 14(a)), the protective function of the second coating film Ps2 is higher than that of the coating film Ps in the comparative example (Figure 8(b)), regardless of the sacrificial layer Sa and the insulating layer N.

[0160] As explained above with reference to Figure 14, according to this 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 greater 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 is the layer with the fewest number of adsorption sites per unit area among the different layers (insulating layer N and sacrificial layer Sa) constituting the laminated structure L. In this embodiment, the specific layer is the sacrificial layer Sa. Thus, in this embodiment, because the number of adsorption sites 12 on the surface of the first coating film Ps1 is large, the protective function of the second coating film Ps2 is higher than that of the coating film Ps (Figure 8(b)) according to the comparative example, regardless of the sacrificial layer Sa and the insulating layer N. Therefore, etching by the first chemical solution C1 can be suppressed on the insulating layer N and the sacrificial layer Sa in the portion of the recess R of the substrate W that does not need to be widened (surface side portion Rn).

[0161] In particular, in this embodiment, the adsorption sites 12 on the surface of the first coating film Ps1 contain hydroxyl groups. Therefore, by using a compound containing a methyl group or a silyl group at its terminal end as the water repellent P, the second coating film Ps2 can be easily formed on the first coating film Ps1.

[0162] In this embodiment, a first coating film Ps1 is formed in the recess R so as to cover the insulating layer N and the sacrificial layer Sa (Figure 9(b)). Consequently, a second coating film Ps2 with high protective function is formed on the first coating film Ps1 (Figure 11(a)). As a result, in the process shown in Figure 12(a), the insulating layer N and the sacrificial layer Sa of the surface portion Rn of the recess R are not etched by the first chemical solution C1. In other words, etching by the first chemical solution C1 can be suppressed in the portion of the recess R that does not need to have its diameter widened (the surface portion Rn of the recess R). On the other hand, etching by the first chemical solution C1 can be performed in the portion of the recess R that needs to have its diameter widened (the deep recess Rf).

[0163] In particular, in the semiconductor device formation method according to the comparative example shown in Figure 6, the protective function of the coating film Ps on the sacrificial layer Sa is reduced, which made it possible for etching to occur on the sacrificial layer Sa in the portion of the recess R where it is not necessary to widen the diameter (the surface portion Rn of the recess R) (Figure 8(c)). In contrast, in the semiconductor device formation method according to this embodiment, by forming the first coating film Ps1 on the sacrificial layer Sa and the insulating layer N, and then forming the second coating film Ps2, etching by the first chemical solution C1 can be suppressed not only on the insulating layer N but also on the sacrificial layer Sa.

[0164] Next, the semiconductor device formation method of this embodiment will be described with reference to Figure 15. Figure 15 is a flowchart of the semiconductor device formation method. The semiconductor device formation method of this embodiment is preferably carried out by the substrate processing apparatus 100 described above with reference to Figures 1 to 3.

[0165] First, in step S10, a first coating film Ps1 is formed in the recess R (Figure 9(b)). Typically, the first coating film Ps1 is formed from the surface portion Rn of the recess R to the deeper portion Rf of the recess. Specifically, a first coating film Ps1 is formed to cover the recess R provided in the laminated structure L supported by the substrate S. Therefore, the insulating layer N and sacrificial layer Sa exposed in the recess R are covered by the first coating film Ps1.

[0166] Next, in step S20, the recess R in the laminated structure L is partially covered (Figures 11(a) and 11(b)). Typically, the surface portion Rn of the recess R is selectively covered. Specifically, a second coating film Ps2 is formed that selectively covers the surface portion Rn (the portion located on the surface side) of the recess R on which the first coating film Ps1 is formed, from above the first coating film Ps1. The second coating film Ps2 covers the surface portion Rn of the recess R, but does not cover the deep portion Rf of the recess. Therefore, the first coating film Ps1 is exposed in the deep portion Rf of the recess.

[0167] Next, in step S30, the diameter of the recess depth Rf is expanded. By applying the chemical solutions (first chemical solution C1, second chemical solution C2) to the recess R, the diameter of the recess depth Rf can be expanded (Figures 12(a), 13(a)). Since the recess R is partially covered with the second coating film Ps2, the diameter of the recess depth Rf that is not covered with the second coating film Ps2 is partially expanded. This allows the diameter of the recess depth Rf to be expanded, thus allowing the diameter of the recess R to be adjusted.

[0168] As explained above with reference to Figure 15, in this embodiment, a second coating film Ps2 is formed on the first coating film Ps1 in the surface-side portion Rn of the recess R (steps S10, S20). Therefore, the protective function of the second coating film Ps2 is enhanced. As a result, in step S30, etching by the chemical solution (first chemical solution C1) can be suppressed on the sacrificial layer Sa and insulating layer N of the portion of the recess R of the substrate W that does not need to be widened (surface-side portion Rn) (Figure 12(a)).

[0169] Next, the semiconductor device formation method of this embodiment will be described with reference to Figure 16. Figure 16 is a flowchart of the semiconductor device formation method. The semiconductor device formation method of this embodiment is preferably carried out using the substrate processing apparatus 100 described above with reference to Figures 1 to 3.

[0170] First, in step S10, a first coating film Ps1 is formed to cover the recess R provided in the laminated structure L supported by the substrate S of the substrate W (Figure 9(b)). In this case, for example, the first coating film Ps1 is formed by the ALD method using an ALD apparatus outside the substrate processing apparatus 100. Alternatively, the first coating film Ps1 may be formed using ozonated water, hydrogen peroxide, or SPM. In this case, the liquid supply unit 130 of the substrate processing apparatus 100 may include a fluid supply unit with a configuration similar to that of the processing liquid supply unit 132. The fluid supply unit then supplies ozonated water, hydrogen peroxide, or SPM to the upper surface Wa of the substrate W. When the insulating layer N is a silicon oxide film and the sacrificial layer Sa is a silicon nitride film, the first coating film Ps1 made of a silicon oxide film can be formed by supplying ozonated water, hydrogen peroxide, or SPM to the recess R.

[0171] Next, in process Sa, the substrate W is loaded into the substrate processing apparatus 100. Here, the substrate W has a base material S and a laminated structure L, the laminated structure L is provided with recesses R, and a first coating film Ps1 is formed in the recesses R.

[0172] Next, in step S20, the recess R is partially covered with the second coating film Ps2 over the first coating film Ps1. Here, the partial covering of the recess R in step S20 is performed by forming the packing layer F in step S21, partially removing the packing layer F in step S22 (forming the partial packing layer Fp), supplying the water repellent in step S23 (forming the second coating film Ps2), and removing the partial packing layer Fp in step S24.

[0173] First, in step S21, a packing layer F is filled into the recess R (Figure 10(a)). Specifically, a packing layer F is formed on top of the first coating film Ps1 to fill the recess R. For example, the processing liquid supply unit 132 supplies processing liquid to the substrate W. This fills the recess R of the substrate W with the packing layer F. Typically, after the processing liquid is supplied, the substrate holding unit 120 increases the rotation speed of the substrate W to shake off any excess processing liquid remaining on the surface of the substrate W to the outside of the substrate W.

[0174] Next, in step S22, a portion of the packed layer F is removed (Figure 10(b)). That is, the packed layer F is partially removed after it has been formed (after step S21). For example, the removal liquid supply unit 134 supplies the removal liquid Ds to the substrate W for a predetermined period of time. When the removal liquid Ds is applied to the packed layer F of the recess R, the packed layer F is partially dissolved and a partial packed layer Fp is formed within the recess R. The time for which the removal liquid Ds is applied is set to partially remove the packed layer F of the recess R. At this time, the packed layer F of the surface portion Rn of the recess R is removed, while the partial packed layer Fp remains in the deeper portion Rf of the recess.

[0175] Alternatively, a partial packed layer Fp may be formed in the recess R by heating the packed layer F for a predetermined period of time. For example, if the packed layer F contains a sublimable substance, a portion of the packed layer F can be sublimated by heating the packed layer F for a predetermined period of time, thereby forming a partial packed layer Fp in the recess R.

[0176] Here, steps S21 and S22 correspond to an example of "a step of forming a partially filled layer Fp which partially fills the deep recess Rf of the recess R from above the first coating film Ps1".

[0177] Next, in step S23, a water-repellent agent P is supplied to the substrate W (Figure 11(a)). That is, the water-repellent agent P is supplied after the partial filling layer Fp is formed (after step S22). The water-repellent agent supply unit 136 supplies the water-repellent agent P to the substrate W. By applying the water-repellent agent P to the recess R in which the partial filling layer Fp is formed in the deep recess Rf, the water-repellent agent P is filled into the surface-side portion Rn of the recess R in which 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, in the surface-side portion Rn of the recess R, the properties of the first coating film Ps1 are changed by the water-repellent agent P, and a second coating film Ps2 is formed on the surface-side portion Rn of the recess R. In this way, by supplying the water-repellent agent P, the second coating film Ps2 is formed on the surface-side portion Rn of the recess R as part of the water-repellent layer, on top of the first coating film Ps1.

[0178] Next, in step S24, the partial filling layer Fp is removed (Figure 11(b)). That is, after the water repellent P is supplied to form the second coating film Ps2 on top of the first coating film Ps1 on the surface side of the recess R (after step S23), the partial filling layer Fp and the water repellent P are removed.

[0179] Here, the portion of the water-repellent layer formed from the water-repellent agent P other than the second coating film Ps2 is removed, and the partial packing layer Fp is also removed. For example, the removal liquid supply unit 134 supplies the removal liquid Ds to the substrate W, thereby dissolving the partial packing layer Fp and replacing the portion of the water-repellent layer other than the second coating film Ps2. At this time, the surface portion Rn of the recess R is covered with the second coating film Ps2 from above the first coating film Ps1, while the first coating film Ps1 is exposed in the deeper part Rf of the recess.

[0180] Alternatively, the partial packed layer Fp may be removed by heating it for a predetermined period of time. For example, if the packed layer F contains a sublimable substance, heating the packed layer F will sublimate a portion of it, thereby removing the partial packed layer Fp from the recess R.

[0181] Next, in step S30, the diameter of the recess depth Rf is expanded. For example, the recess depth Rf that is not covered by the second coating film Ps2 is partially etched, and the recess diameter is widened.

[0182] Here, the expansion of the diameter of the recess depth Rf 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.

[0183] First, in step S31, the first chemical solution C1 is supplied to the recess R (Figure 12(a)). For example, the chemical solution supply unit 138 supplies the first chemical solution C1 to the substrate W. As a result, the deep recess Rf of the recess R that is not covered by the second coating film Ps2 is partially etched. That is, the deep recess Rf is etched with the first chemical solution C1 in such a way that its diameter is widened.

[0184] Next, in step S32, the second coating film Ps2 is removed from the recess R (Figure 12(b)). In other words, the second coating film Ps2 is removed after step S31, in which etching is performed with the first chemical solution C1. For example, the second coating film Ps2 may be removed by ashing with ultraviolet irradiation or heat treatment. Note that step S32 may be performed outside the substrate processing apparatus 100. Alternatively, the second coating film Ps2 may be removed by supplying SPM. In this case, the liquid supply unit 130 of the substrate processing apparatus 100 may include a fluid supply unit with a configuration similar to that of the processing liquid supply unit 132. The fluid supply unit then supplies SPM to the upper surface Wa of the substrate W.

[0185] Next, in step S33, the first coating film Ps1 is removed from the recess R (Figure 13(a)). In other words, the first coating film Ps1 is removed after step S32, in which the second coating film Ps2 is removed. Specifically, the first coating film Ps1 is removed by supplying the second chemical solution C2 to the recess R. In this 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. As a result, the first coating film Ps1 in the recess R is removed by the second chemical solution C2. In addition, the deep recess Rf is further etched by the second chemical solution C2. Then, after the removal of the first coating film Ps1 and etching are completed, the second chemical solution C2 is removed from the recess R (Figure 13(b)).

[0186] Next, in step Sb, the substrate W is removed from the substrate processing apparatus 100. In this manner, a substrate W with suppressed variations in recess diameter can be formed.

[0187] As described above with reference to Figure 16, according to this embodiment, a first coating film Ps1 is formed in the recess R (step S10), and a second coating film Ps2 is formed on the first coating film Ps1 (step S20). Therefore, etching by the first chemical solution C1 can be suppressed not only on the insulating layer N but also on the sacrificial layer Sa in the surface portion Rn of the recess R. In other words, etching by the first chemical solution C1 can be suppressed on the portion of the recess R of the substrate W that does not need to be widened (surface portion Rn).

[0188] Furthermore, in this embodiment, the material of the first coating film Ps1 and the material of the second coating film Ps2 are different. Therefore, by performing the step S32 for removing the second coating film Ps2 and the step S33 for removing the first coating film Ps1 at different timings, the first coating film Ps1 and the second coating film Ps2 can be effectively removed by methods appropriate to the properties of each of them.

[0189] Furthermore, in this embodiment, in step S33, the first coating film Ps1 is removed with the second chemical solution C2, and the recess depth Rf is etched with the second chemical solution C2. Therefore, the diameter of the recess depth Rf can be widened to the target value while taking into account the thickness (length along the x-direction) of the first coating film Ps1 to be removed.

[0190] Furthermore, in this embodiment, a partially filled layer Fp is formed to partially fill the recess depth Rf from above the first coating film Ps1, and then a second coating film Ps2 is formed with a water-repellent agent P (step S20). In this way, the second coating film Ps2 can be formed on the first coating film Ps1 in the surface portion Rn of the recess R using a simple process.

[0191] Specifically, in this embodiment, a filling layer F is formed on top of the first coating film Ps1 (step S21), and then a partial filling layer Fp is formed in the deeper recess Rf (step S22), after which a second coating film Ps2 is formed with a water-repellent agent P (step S23). Therefore, the second coating film Ps2 can be easily formed on the first coating film Ps1 in the surface portion Rn of the recess R.

[0192] Next, the substrate processing apparatus 100 of this embodiment will be described with reference to Figure 17. Figure 17 is a schematic diagram of the substrate processing apparatus 100. The substrate processing apparatus 100 can process multiple substrates W at once.

[0193] The substrate processing apparatus 100 comprises a substrate holding section 120 and a liquid supply section 130. The liquid supply section 130 includes a processing liquid supply section 132, a removal liquid supply section 134, a water repellent supply section 136, and a chemical solution supply section 138. The processing liquid supply section 132, the removal liquid supply section 134, the water repellent supply section 136, and the chemical solution supply section 138 each store liquid.

[0194] The processing liquid supply unit 132 includes a processing liquid storage tank 132t. The processing liquid is stored in the processing liquid storage tank 132t. A packed bed 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.

[0195] The removal liquid supply unit 134 includes a removal liquid storage tank 134t. The removal liquid is stored in the removal liquid storage tank 134t. The removal liquid can remove the packed layer formed from the processing liquid. By controlling the time the removal liquid is supplied, the packed layer can be selectively removed from the substrate W.

[0196] Any solvent that is soluble in any of the resins can be used as the removal solution. Examples of removal solutions include organic solvents such as paint thinner, toluene, acetic acid esters, alcohols, and glycols, as well as acidic solutions such as acetic acid, formic acid, and hydroxyacetic acid.

[0197] The water-repellent supply unit 136 includes a water-repellent storage tank 136t. Liquid water-repellent is stored in the water-repellent storage tank 136t. The water-repellent forms a water-repellent layer on the substrate W. The water-repellent is a water-repellent agent that hydrophobicizes 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 a non-chloro water-repellent agent. The non-chloro water-repellent agent includes, for example, at least one of dimethylsilyldimethylamine, dimethylsilyldiethylamine, hexamethyldisilazane, tetramethyldisilazane, bis(dimethylamino)dimethylsilane, N,N-dimethylaminotrimethylsilane, N-(trimethylsilyl)dimethylamine, and an organosilane compound.

[0198] The chemical supply unit 138 includes a chemical storage tank 138t. The chemical is stored in the chemical storage tank 138t. The substrate W can be treated with the chemical by chemical treatment using the chemical. Chemical treatment makes it possible to perform etching, surface treatment, property imparting, film formation, and removal of at least a portion of the film on the substrate W. Typically, the chemical is an etching solution used for etching the substrate W. In this embodiment, the chemical is used as a first chemical C1 and a second chemical C2.

[0199] The chemical solution contains hydrofluoric acid. For example, the chemical solution contains hydrofluoric acid (dilute hydrofluoric acid) diluted in a ratio of 1:100 to 1:2000. For example, the hydrofluoric acid may be heated to a temperature of 40°C to 70°C, or to a temperature of 50°C to 60°C. However, the hydrofluoric acid does not need to be heated. The chemical solution may also contain water or phosphoric acid.

[0200] Furthermore, the chemical solution may also contain hydrogen peroxide. Alternatively, 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). Alternatively, the chemical solution may be fluoride-containing phosphoric acid. Fluoride-containing phosphoric acid is phosphoric acid containing fluoride. In this case, the fluoride is ammonium fluoride or ammonium hydrogen difluoride.

[0201] The substrate holder 120 holds the substrate W. The direction of the normal to the main surface of the substrate W held by the substrate holder 120 is parallel to the Y direction. The substrate holder 120 moves the substrate W while holding multiple substrates W. For example, the substrate holder 120 moves vertically upward or vertically downward while holding the substrate W. Alternatively, the substrate holder 120 may move horizontally while holding the substrate W.

[0202] The substrate holder 120 includes a main plate 122b and a holding rod 124b. The main plate 122b is a plate extending in the vertical direction (Z direction). The holding rod 124b extends horizontally (Y direction) from one main surface of the main plate 122b. Here, two holding rods 124b extend in the Y direction from one main surface of the main plate 122b. Multiple substrates W are arranged in the front-to-back direction of the paper, and the lower edges of each substrate W are held in an upright position (vertical position) by the multiple holding rods 124b.

[0203] The substrate processing apparatus 100 further comprises a control device 101. The control device 101 includes a control unit 102 and a storage unit 104. The control unit 102 controls the substrate holding unit 120.

[0204] In the substrate processing apparatus 100 of this embodiment, the control unit 102 can adjust the diameter of the recess R provided in the laminated structure L of the substrate W by processing the substrate W held in the substrate holding unit 120 with different liquids, similar to how the single-wafer type was described with reference to Figures 9 to 16.

[0205] In this embodiment, a first coating film Ps1 is formed in the recess R of the substrate W by the ALD method, and the substrate W is then transported to the substrate processing apparatus 100. However, the first coating film Ps1 may be formed using ozonated water, hydrogen peroxide, or SPM. In this case, the liquid supply unit 130 includes a fluid supply unit with a configuration similar to that of the processing liquid supply unit 132 for storing, for example, ozonated water, hydrogen peroxide, or SPM.

[0206] In this embodiment, the second coating film Ps2 may 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.

[0207] In the description with reference to Figures 1 to 17, a memory element Se is placed in the recess R of the substrate W, but this embodiment is not limited to this. A dummy memory element having a similar configuration to the memory element Se but not used as a memory element may be formed in the recess R of the substrate W. Alternatively, a contact plug for electrically connecting to the memory element Se may be formed in the recess R of the substrate W.

[0208] Next, the semiconductor element 300 formed by the semiconductor element formation method of this embodiment will be described with reference to Figure 18. Figure 18 is a schematic diagram of the semiconductor element 300.

[0209] The semiconductor element 300 is provided with multiple recesses R. These multiple recesses R include memory recesses Rs where memory elements Se are located, and contact recesses Rc where contact plugs Cp are located. The contact recesses Rc are electrically connected to the conductive layer M.

[0210] According to the semiconductor device formation method of this embodiment, not only the diameter of the memory recess Rs but also the diameter of the contact recess Rc can be made uniform from the surface to the depth. Therefore, the strength supporting the semiconductor device by the contact recess Rc can be made uniform.

[0211] Embodiments of the present invention have been described above with reference to the drawings. However, the present invention is not limited to the embodiments described above, and can be implemented in various forms without departing from the spirit of the invention. Furthermore, various inventions can be formed by appropriately combining the multiple components disclosed in the above embodiments. For example, some components may be deleted from all the components shown in the embodiments. Furthermore, components from different embodiments may be appropriately combined. The drawings schematically show each component in order to make them easy to understand, and the thickness, length, number, spacing, etc. of each component shown may differ from the actual dimensions due to the convenience of drawing creation. Also, the material, shape, dimensions, etc. of each component shown in the above embodiments are examples and are not particularly limited, and various modifications are possible without substantially departing from the effects of the present invention. [Industrial applicability]

[0212] The present invention is suitably used in semiconductor device formation methods. [Explanation of Symbols]

[0213] 100 Substrate Processing Equipment 110 Chamber 120 Board holding part 130 Liquid supply section 132 Processing liquid supply unit 134 Removal liquid supply section 136 Water repellent supply unit 138 Chemical Solution Supply Unit W board

Claims

1. A step of forming a first coating film that covers a recess provided in a laminated structure supported by a substrate, A step of forming a second coating film that selectively covers the portion of the recess on the surface side of the recess on which the first coating film is formed, The process involves etching the deep recess with the first chemical solution in order to widen the width of the deep recess, which is the portion of the recess not covered by the second coating film. A semiconductor device formation method encompassing this.

2. A step of removing the second coating film after the step of etching with the first chemical solution, The process of removing the first coating film is performed after the step of removing the second coating film. The semiconductor device formation method according to claim 1, further encompassing the above.

3. The semiconductor device forming method 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 recess depth is etched with the second chemical solution.

4. The semiconductor device forming method according to claim 1 or claim 2, wherein in the step of forming the first coating film, the first coating film is formed by the ALD method, ozonated water, hydrogen peroxide solution, or a sulfuric acid hydrogen peroxide solution mixture.

5. 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 the different layers constituting the laminated structure. The semiconductor device forming method according to claim 1 or claim 2, wherein the specific layer is the layer with the fewest number of adsorption sites per unit area among the different layers constituting the stacked structure.

6. The semiconductor device formation method according to claim 5, wherein the adsorption site contains a hydroxyl group.

7. The step of forming the aforementioned second coating film is: A step of forming a partially filled layer that partially fills the deeper part of the recess from above the first coating film, A step of supplying a water-repellent agent after forming the aforementioned partial filling layer, The process involves supplying the water-repellent agent to form the second coating on the surface side of the recess over the first coating, and then removing the partial filling layer and the water-repellent agent. A method for forming a semiconductor device according to claim 1 or claim 2, including the above.

8. The step of forming the partial packed layer is, A step of forming a filling layer on top of the first coating film to fill the recess, A step of partially removing the packed layer after forming the packed layer. A method for forming a semiconductor device according to claim 7, including the method described in claim 7.

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