Substrate processing method and substrate processing apparatus

Abstract

This invention provides a technique for forming a metal-containing film having an aperture pattern and an inverted pattern of a resist film. [Solution] A substrate processing method according to one aspect of the present disclosure comprises the steps of: (a) preparing a substrate having a base film and a resist film disposed on the base film and having a first opening pattern formed thereon; (b) supplying a raw material gas containing a metal-containing precursor to fill the openings of the first opening pattern with a flowable film containing the metal contained in the metal-containing precursor at a temperature lower than the boiling point of the metal-containing precursor, and then curing the flowable film to form a metal-containing film in the openings; and (c) removing the resist film to form the metal-containing film having a second opening pattern that is the inverse of the first opening pattern.

Description

Technical Field

[0001] The present disclosure relates to a substrate processing method and a substrate processing apparatus.

Background Art

[0002] There is known a technique in which a thin film of metal oxide or metal nitride is selectively formed on the surface of a substrate layer that is the base of a patterned resist, the thin film of metal oxide or metal nitride on the surface of the substrate layer is left, and the resist is removed (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The present disclosure provides a technique for forming a metal-containing film having a pattern inverted from the opening pattern of a resist film.

Means for Solving the Problems

[0005] A substrate processing method according to an aspect of the present disclosure includes: (a) preparing a substrate having an underlying film and a resist film disposed on the underlying film and having a first opening pattern formed therein; (b) supplying a source gas containing a metal-containing precursor, filling a fluid film containing a metal contained in the metal-containing precursor into the opening of the first opening pattern at a temperature lower than the boiling point of the metal-containing precursor, and then forming a metal-containing film in the opening by curing the fluid film; and (c) removing the resist film to form the metal-containing film having a second opening pattern inverted from the first opening pattern.

Effects of the Invention

[0006] According to this disclosure, a metal-containing film having an opening pattern and an inverted pattern of a resist film can be formed. [Brief explanation of the drawing]

[0007] [Figure 1] This is a flowchart showing the substrate processing method according to the embodiment. [Figure 2] This is a schematic cross-sectional view illustrating the substrate processing method according to the embodiment. [Figure 3] This is a schematic diagram illustrating an example of the reaction process from a metal-containing precursor to the formation of a fluidized film. [Figure 4] This is a schematic diagram illustrating an example of the effects of the substrate processing method according to the embodiment. [Figure 5] This figure shows an example of a processing system according to the embodiment. [Figure 6] This figure shows an example of a processing apparatus according to the embodiment. [Modes for carrying out the invention]

[0008] Hereinafter, exemplary embodiments of the present disclosure, not limited to those described herein, will be described with reference to the attached drawings. In all attached drawings, identical or corresponding members or components are denoted by the same or corresponding reference numerals, and redundant descriptions are omitted.

[0009] [Embodiment] (Substrate processing method) The substrate processing method according to the embodiment will be described with reference to Figures 1 to 3. Figure 1 is a flowchart of the substrate processing method according to the embodiment. Figure 2 is a schematic cross-sectional view illustrating the substrate processing method according to the embodiment. Figure 3 is a schematic diagram showing an example of the reaction process from the metal-containing precursor to the formation of a flow film.

[0010] The substrate processing method according to the embodiment includes steps S11 to S14 shown in Figure 1. Step S11 includes preparing the substrate 100. Preparing the substrate 100 includes, for example, loading the substrate 100 into the processing container 10 of the processing apparatus PM1, which is part of the processing system PS described separately with reference to Figures 5 and 6. Preparing the substrate 100 also includes placing the substrate 100 loaded into the processing container 10 onto the mounting table 20. Note that the processing apparatus PM1 is an example of a substrate processing apparatus.

[0011] Figure 2(a) is a schematic cross-sectional view of the prepared substrate 100. As shown in Figure 2(a), the substrate 100 has, for example, an underlayer 110 and a resist film 120 placed on the underlayer 110. The underlayer 110 has, for example, a spin-on carbon film. The spin-on carbon film is a carbon-containing film that mainly contains carbon (C). The underlayer 110 may be a film other than the spin-on carbon film. Films other than the spin-on carbon film include, for example, single-crystal silicon films, polycrystalline silicon films, amorphous silicon films, silicon oxide films, silicon nitride films, hafnium oxide films, zirconium oxide films, ITO films (Indium Tin Oxide), and IGZO films. The underlayer 110 may also have other films such as a back surface anti-reflective film. The underlayer 110 is a film that has etching selectivity with respect to the metal-containing film 132, which will be described later.

[0012] The resist film 120 is formed from a photoresist composition. The photoresist composition is, for example, a chemically amplified type. The resist film 120 has a first opening pattern including an opening 120r. The resist film 120 may or may not have a functional group that bonds with the metal M in step S12 described later. The functional group can be any common type, such as a carboxyl group, a phenyl group, or an acrylic group.

[0013] Step S12 comprises steps S12a and S12b. Step S12a includes supplying a raw material gas containing a metal-containing precursor to fill the opening 120r with a fluidized membrane 131 containing the metal M contained in the metal-containing precursor. Step S12a may also include filling the fluidized membrane 131 such that the upper surface of the metal-containing membrane 132 is located above the upper surface of the resist membrane 120. Step S12a is performed, for example, using the processing apparatus PM1 described later.

[0014] In step S12a, the fluidized film 131 is filled into the opening 120r at a temperature lower than the boiling point of the metal-containing precursor. Specifically, the temperature of the substrate 100 in step S12a is lower than the boiling point of the metal-containing precursor. A temperature lower than the boiling point of the metal-containing precursor is, for example, a temperature below room temperature. However, the temperature of the substrate 100 in step S12a may be higher than room temperature, as long as it is lower than the boiling point of the metal-containing precursor.

[0015] When the raw material gas is supplied into the processing container 10, the pressure inside the processing container 10 is reduced to a pressure lower than atmospheric pressure (for example, a vacuum atmosphere). That is, the boiling point of the metal-containing precursor is the boiling point under the pressure inside the processing container 10 when the raw material gas is supplied. For example, if the pressure inside the processing container 10 is reduced to a pressure lower than atmospheric pressure, the boiling point of the metal-containing precursor refers to the boiling point under the reduced pressure inside the processing container 10, not the boiling point under atmospheric pressure.

[0016] Metal-containing precursors contain metal M. Examples of metal-containing precursors include aminometal compounds. Aminometal compounds are compounds containing metal M and one or more amino groups bonded to metal M. Examples of aminometal compounds include bis-DMADMS (Bis(dimethylamino)dimethylsilane), TDMAS (Tris(dimethylamino)silane), BTBAS (Bis(t-butylamino)silane), BDEAS (Bis(diethylamino)silane), Bis-DMADMSn (Bis(dimethylamino)dimethyltin), TDMASn (Tetrakis(dimethylamino)tin), TDMAHf (Tetrakis(dimethylamino)hafnium), and TDMATi (Tetrakis (dimethylamino)titanium), TDMAGe(Tris(dimethylamino)germanium), Bis-BTMSG(Bis[bis(trimethylsilyl)amide]germanium), TDMAZr(Tetrakis(dimethylamino) zirconium), BTBIBDMAW (Bis(tert-butylimino)bis(dimethylamino)tungsten), Al(NMe2)3(Tris(dimethylamino)aluminum), Al2(NMe2)6(Tris(dimethylamino)alane dimer) is used.

[0017] Metal M may include metalloids such as boron (B), silicon (Si), germanium (Ge), arsenic (As), antimony (Sb), and tellurium (Te). Examples of metal M include Si, Ge, hafnium (Hf), tin (Sn), titanium (Ti), zirconium (Zr), tungsten (W), or aluminum (Al). However, metal M may be a different metal from these.

[0018] Here, referring to FIG. 3, an example of the reaction process from the metal-containing precursor to the formation of the fluid film 131 will be described. FIG. 3(a) shows bis-DMADMS, which is an example of the metal-containing precursor. FIG. 3(b) shows an example of silanol, which is an intermediate generated from the metal-containing precursor. FIG. 3(c) shows polydimethylsiloxane, which is an example of the fluid film 131. FIG. 3(d) shows octamethylcyclotetrasiloxane, which is another example of the fluid film 131.

[0019] However, the metal-containing precursor is not limited to the compound shown in FIG. 3(a). The metal-containing precursor may be, for example, an amino metal compound containing a metal M different from Si, such as Ge, Hf, Sn, Ti, Zr, W, and Al. Also, when the metal-containing precursor is an amino metal compound, the amino group contained in the amino metal compound may contain, for example, a methyl group as shown in FIG. 3(a). However, the amino group contained in the amino metal compound may contain an organic group different from the methyl group. The organic group different from the methyl group is, for example, a hydrogen (H) atom or an alkyl group other than the methyl group. Also, the metal-containing precursor may be a compound containing a metal M different from these metals.

[0020] The intermediate generated from the metal-containing precursor is not limited to the silanol shown in FIG. 3(b). The intermediate generated from the metal-containing precursor can be appropriately changed according to the type of the metal-containing precursor. The polysiloxane as the fluid film 131 is not limited to the polydimethylsiloxane shown in FIG. 3(c) and the octamethylcyclotetrasiloxane shown in FIG. 3(d). The polysiloxane as the fluid film 131 may be, for example, other polysiloxanes such as hexamethylcyclotrisiloxane and decamethylcyclopentasiloxane. The fluid film 131 can be appropriately changed according to the type of the intermediate generated from the metal-containing precursor.

[0021] When the raw material gas is supplied into the processing container 10, the bis-DMADMS shown in Figure 3(a) reacts with H2O molecules to produce, for example, silanol and dimethylamine shown in Figure 3(b). The H2O molecules may also be water vapor (H2O molecules) contained in the additive gas supplied to the processing container 10 along with the raw material gas. Alternatively, the H2O molecules may be H2O molecules contained in the resist film 120. Furthermore, the H2O molecules may be H2O molecules that remained in the processing container 10 before the raw material gas was supplied, or H2O molecules that entered the processing container 10 from the outside when the raw material gas was supplied.

[0022] After bis-DMADMS reacts with H2O molecules to produce silanols, dehydration condensation reactions occur between multiple silanols to produce polysiloxanes such as polydimethylsiloxane shown in Figure 3(c) and octamethylcyclotetrasiloxane shown in Figure 3(d). Meanwhile, the H2O molecules removed in the silanol dehydration condensation reaction react with bis-DMADMS in the raw material gas remaining in the processing container 10. This generates new silanols. In other words, once the reaction between bis-DMADMS and H2O molecules begins, polysiloxanes such as those shown in Figures 3(c) and 3(d) continue to be produced in the processing container 10, regardless of whether new H2O molecules are supplied.

[0023] A fluidized film 131 is formed when the polysiloxane produced through the reaction process shown in Figure 3 adheres to the substrate 100 (the surface of the resist film 120). Since the temperature of the substrate 100 is set to a temperature lower than the boiling point of bis-DMADMS in step S12a, the fluidized film 131 contains liquid-phase polysiloxanes such as liquid-phase polydimethylsiloxane and liquid-phase octamethylcyclotetrasiloxane. Therefore, the fluidized film 131 is fluid during the period in which step S12a is performed. Even if the metal-containing precursor is a metal-containing compound different from bis-DMADMS, the fluidized film 131 contains a liquid-phase compound produced using the metal-containing precursor as a starting material.

[0024] Figure 2(b) is a schematic cross-sectional view of the initial stage when the fluidized film 131 is attached to the surface of the resist film 120 (side and top surfaces of the resist film 120). Figure 2(c) is a schematic cross-sectional view of the stage when the fluidized film 131 is filled into the opening 120r. In step S12a, the temperature of the substrate 100 is set to a temperature lower than the boiling point of the metal-containing precursor, which suppresses the bonding between the metal M contained in the metal-containing precursor and the functional groups contained in the resist film 120. In other words, the penetration of metal M into the resist film 120 is limited. Therefore, as shown in Figure 2(b), the fluidized film 131 is formed on the surface of the resist film 120 in the initial stage. Also, as a result of limiting the penetration of metal M into the resist film 120, the fluidized film 131 is deposited on the outside of the resist film 120, as shown in Figure 2(c). In other words, the fluidized film 131 is filled into the opening 120r located on the outside of the resist film 120. The fluidized membrane 131 fills the opening 120r while maintaining its fluidity. Therefore, voids and seams within the membrane can be reduced compared to the case where a solid-phase compound is embedded in the opening 120r. This allows for the formation of a conformal fluidized membrane 131.

[0025] Step S12b is performed after step S12a. Step S12b includes supplying an oxidizing gas into the processing container 10 and curing the fluidized film 131 filled in the opening 120r to form a metal-containing film 132 on the opening 120r. In step S12b as well, the pressure inside the processing container 10 may be reduced to a pressure lower than atmospheric pressure (for example, a vacuum atmosphere). Step S12b is performed, for example, using the processing apparatus PM1 described later.

[0026] As an oxidizing agent, for example, O2 molecules, ozone (O3) molecules, CO2 molecules, or O2 plasma or CO2 plasma can be used. Figure 2(d) is a schematic cross-sectional view of the substrate 100 after the metal-containing film 132 has been obtained. As the fluidized film 131 hardens with the oxidizing agent, the metal-containing film 132 is formed in the opening 120r, as shown in Figure 2(d). As mentioned above, since voids and seams in the fluidized film 131 are reduced, voids and seams in the metal-containing film 132 obtained by hardening the fluidized film 131 are also reduced. That is, a conformal metal-containing film 132 can be formed in step S12b. If the upper surface of the fluidized film 131 is located above the upper surface of the resist film 120, the upper surface of the metal-containing film 132 is also located above the upper surface of the resist film 120.

[0027] The metal-containing film 132 is a film containing metal M and oxygen (O). The metal-containing film 132 may also further contain organic groups derived from the metal-containing precursor. Examples of organic groups derived from the metal-containing precursor include H atoms and alkyl groups. If the fluidized film 131 contains polysiloxane, the metal-containing film 132 is a silicon oxide-like film.

[0028] If the metal-containing precursor is a compound containing Sn, such as bis-DMADMSn and TDMASn, the metal-containing film 132 is a tin oxide-like film. If the metal-containing precursor is a compound containing Hf, such as TDMAHf, the metal-containing film 132 is a hafnium oxide-like film. If the metal-containing precursor is a compound containing Ti, such as TDMATi, the metal-containing film 132 is a titanium oxide-like film. If the metal-containing precursor is a compound containing Ge, such as TDMAGe, the metal-containing film 132 is a germanium oxide-like film. If the metal-containing precursor is a compound containing Zr, such as TDMAZr, the metal-containing film 132 is a zirconium oxide-like film. If the metal-containing precursor is a compound containing W, such as BTBIBDMAW, the metal-containing film 132 is a tungsten oxide-like film. If the metal-containing precursor is an Al-containing compound, such as Al(NMe2)3, the metal-containing film 132 is an aluminum oxide-like film.

[0029] Furthermore, after step S12a, the fluidized film 131 can also be cured by, for example, opening the processing container 10 to the atmosphere and introducing O2 molecules into the processing container 10. That is, a metal-containing film 132 can be obtained by curing the fluidized film 131 with O2 molecules introduced into the processing container 10. In this case, the supply of oxidizing gas into the processing container 10 in step S12b can be omitted.

[0030] Step S12 may include repeating steps S12a and S12b multiple times. The number of times steps S12a and S12b are repeated can be appropriately changed depending on the amount of metal-containing film 132 deposited.

[0031] Step S12 may include supplying a purge gas into the processing container 10 after step S12b. The purge gas discharges any metal-containing precursor remaining in the processing container 10 to the outside of the processing container 10. The purge gas also discharges any excess metal-containing precursor physically adsorbed on the surface of the metal-containing film 132 to the outside of the processing container 10. The purge gas is, for example, nitrogen (N2) gas or argon (Ar) gas.

[0032] An example of the processing conditions for step S12 is as follows: • Flow rate of raw material gas: 1 sccm to 100 sccm • Flow rate of added gas: 1 sccm to 100 sccm • Oxidizing gas flow rate: 100 sccm to 1000 sccm • Temperature of substrate 100: -20°C to 40°C (however, not exceeding the boiling point of the metal-containing precursor under the pressure inside the processing container 10.) • Temperature inside the processing container 10, excluding the substrate 100: 30°C to 200°C • Processing pressure: 1 Torr ~ 500 Torr (133 Pa ~ 66660 Pa) Processing time: 60 seconds to 1200 seconds

[0033] If, in step S12, the metal-containing film 132 is formed such that its upper surface is above the upper surface of the resist film 120, then step S13 is performed after step S12. Step S13 includes removing the metal-containing film 132 from the resist film 120 to expose the resist film 120. Step S13 is performed, for example, using the processing apparatus PM2 described later.

[0034] Figure 2(e) is a schematic cross-sectional view of the substrate 100 after the metal-containing film 132 on the resist film 120 has been removed. As shown in Figure 2(e), when the metal-containing film 132 on the resist film 120 is removed, the upper surface of the metal-containing film 132 is located on the same plane as, for example, the upper surface of the resist film 120.

[0035] In step S13, the metal-containing film 132 on the resist film 120 is etched to expose the resist film 120. The etching gas used for etching the metal-containing film 132 on the resist film 120 is, for example, a halogen-containing gas such as fluorine (F), chlorine (Cl), or bromine (Br), or argon gas. Examples of gases containing F are CF4 gas or SF6 gas. Examples of gases containing Cl are Cl2 gas or BCl3 gas. Examples of gases containing Br are HBr gas. The etching gas may be a single gas or a mixed gas. The etching gas can be appropriately selected according to the composition of the metal-containing film 132.

[0036] If the metal-containing film 132 is a silicon oxide-like film, for example, CF4 gas can be used as the etching gas. If the metal-containing film 132 is a tin oxide-like film, for example, a mixed gas of HBr gas and Ar gas, or CF4 gas can be used as the etching gas. If the metal-containing film 132 is a hafnium oxide-like film, for example, a mixed gas of Cl2 gas and BCl3 gas, SF6 gas, or a mixed gas of CF4 gas and H2 gas can be used as the etching gas. If the metal-containing film 132 is a titanium oxide-like film or a tungsten oxide-like film, for example, a mixed gas of Cl2 gas and BCl3 gas can be used as the etching gas. If the metal-containing film 132 is a germanium oxide-like film, a zirconium oxide-like film, or an aluminum oxide-like film, an etching gas capable of removing these films can be appropriately selected.

[0037] In step S13, the exposure of the upper surface of the resist film 120 can be determined, for example, based on a detection signal output from the OES (Optical Emission Spectrometer) of the processing apparatus PM2. In step S13, for example, if the OES detects a carbon component contained in the resist film 120, the etching process of the metal-containing film 132 is stopped.

[0038] If the metal-containing film 132 is formed in step S12 such that the resist film 120 is exposed, step S13 may be omitted.

[0039] Step S14 is performed after step S13. Step S14 includes removing the resist film 120 and forming a metal-containing film 132 having a first opening pattern and a second opening pattern that is inverted. Specifically, the resist film 120 with its top surface exposed is etched, while the metal-containing film 132 in the opening 120r of the resist film 120 is left intact. As the resist film 120 is removed, a second opening pattern including the opening 132r is formed in the metal-containing film 132.

[0040] Figure 2(f) is a schematic cross-sectional view of the substrate 100 after the second opening pattern has been formed. As shown in Figure 2(f), the second opening pattern is an inverted pattern of the first opening pattern of the resist film 120. That is, the opening 132r is located where the resist film 120 was, and the metal-containing film 132 is located where the opening 120r of the resist film 120 was.

[0041] The etching gas used for etching the resist film 120 is, for example, a gas containing oxygen. Examples of oxygen-containing gases are O2 gas, CO2 gas, or COS gas. The etching gas used for etching the resist film 120 can be appropriately selected depending on the composition of the resist film 120 and its selectivity ratio with the metal-containing film 132.

[0042] The substrate processing method according to the embodiment may further include a step after step S14 in which a portion of the underlayer film 110 is removed using the metal-containing film 132 as a mask. Figure 2(g) is a schematic cross-sectional view showing the substrate 100 after a portion of the underlayer film 110 has been removed. As shown in Figure 2(g), the second opening pattern is transferred to the underlayer film 110 by removing a portion of the underlayer film 110 using the metal-containing film 132 as a mask.

[0043] However, if the underlayer film 110 is a carbon-containing film such as a spin-on carbon film, as the resist film 120 is removed in step S14, a portion of the underlayer film 110 that overlapped with the resist film 120 can be removed. In this case, it is not necessary to remove a portion of the underlayer film 110 by performing an etching process separate from the etching process for removing the resist film 120.

[0044] Considering the etching selectivity of the undercoat 110 for the metal-containing film 132, the following are examples of combinations of the undercoat 110 and the metal-containing film 132. When the metal-containing film 132 is a silicon oxide-like film, the undercoat 110 is, for example, a carbon-containing film, a single-crystal silicon film, a polycrystalline silicon film, an amorphous silicon film, a silicon nitride film, a hafnium oxide film, a zirconium oxide film, an ITO film, or an IGZO film. When the metal-containing film 132 is a tin oxide-like film, the undercoat 110 is, for example, a carbon-containing film, a single-crystal silicon film, a polycrystalline silicon film, an amorphous silicon film, a silicon oxide film, or a silicon nitride film. When the metal-containing film 132 is a hafnium oxide-like film, the undercoat 110 is, for example, a carbon-containing film, a single-crystal silicon film, a polycrystalline silicon film, an amorphous silicon film, a silicon oxide film, or a silicon nitride film. When the metal-containing film 132 is a titanium oxide-like film or a tungsten oxide-like film, the undercoat film 110 is, for example, a carbon-containing film. When the metal-containing film 132 is a germanium oxide-like film, a zirconium oxide-like film, or an aluminum oxide-like film, the undercoat film 110 can be appropriately selected according to the etching selectivity of the undercoat film 110 for these films.

[0045] When the undercoat 110 is, for example, a single-crystal silicon film, a polycrystalline silicon film, an amorphous silicon film, a silicon oxide film, or a silicon nitride film, a gas containing F can be used as the etching gas for etching the undercoat 110. Examples of gases containing F include CF4 gas, SF6 gas, NF3 gas, CH2F2 gas, CH3F gas, CHF3 gas, C4F6 gas, or C4F8 gas.

[0046] If the undercoat 110 is, for example, a hafnium oxide film or a zirconium oxide film, a gas containing Cl can be used as the etching gas for etching the undercoat 110. Examples of Cl-containing gases are Cl2 gas or BCl3 gas.

[0047] If the undercoat 110 is, for example, an ITO film or an IGZO film, a gas containing H can be used as the etching gas for etching the undercoat 110. Examples of gases containing H include H2 gas and CH4 gas.

[0048] The gas used to etch the undercoat 110 may be a single gas or a mixed gas.

[0049] Incidentally, a substrate processing method is known in which an immersion gas containing amino metal compounds or the like as raw materials is supplied into a processing container 10, and the metal M contained in the raw materials is immersed in the resist film 120 made of a sparse polymer to improve the etching resistance of the resist film 120. In the conventional substrate processing method, in order to immerse the metal M into the interior of the resist film 120, the temperature of the substrate 100 when supplying the immersion gas is raised to near the glass transition temperature of the resist film 120. At this time, the temperature of the substrate 100 may be higher than the boiling point of the raw materials. Furthermore, after immersing the metal M into the interior of the resist film 120, a part of the underlayer film 110 is removed using the resist film 120 containing the metal M as a mask, and the first opening pattern of the resist film 120 is transferred to the underlayer film 110.

[0050] However, when using conventional substrate processing methods, the resist film 120 swells due to the influence of the infiltrated metal M. As a result, the roughness of the first opening pattern in the resist film 120, such as LER (Line Edge Roughness) and LWR (Line Width Roughness), may increase compared to the roughness of the first opening pattern in the resist film 120 before infiltration.

[0051] In contrast, in the substrate processing method according to the embodiment, a fluidized film 131 is filled into the openings 120r of the resist film 120 at a temperature lower than the boiling point of the metal-containing precursor, and then the fluidized film 131 is cured to form a metal-containing film 132. This makes it possible to obtain a conformal metal-containing film 132 with reduced voids and seams. Furthermore, in the substrate processing method according to the embodiment, after forming the metal-containing film 132, the resist film 120 is removed to form a metal-containing film 132 having a second opening pattern that is the inverse of the first opening pattern. That is, the roughness of the first opening pattern of the resist film 120 is not reflected in the second opening pattern obtained using the substrate processing method according to the embodiment. As a result, a second opening pattern with reduced roughness compared to the first opening pattern can be obtained.

[0052] Furthermore, using conventional substrate processing methods, metal M penetrates into bridge defects BD present within the openings 120r of the resist film 120, leaving behind a portion of the underlying film 110 that overlaps with the bridge defects BD. Bridge defects BD are resist residues that bridge adjacent line portions. In contrast, in the substrate processing method according to this embodiment, as shown in Figure 4, bridge defects BD present within the openings 120r of the resist film 120 are contained within the fluidized film 131. By curing the fluidized film 131 to form a metal-containing film 132 and creating a second opening pattern that is an inverse of the first opening pattern, it is possible to prevent the presence of bridge defects BD within the openings 132r. As a result, an opening pattern with fewer bridge defects BD can be obtained compared to conventional methods.

[0053] (Examples) Next, an example of the substrate processing method according to the embodiment will be described. However, the substrate processing method of this disclosure is not limited to the examples.

[0054] Example 1 is a substrate 100 prepared by carrying out steps S11 to S14 described above. The metal-containing film 132 on the substrate 100 has a second opening pattern. In Example 1, a gas containing bis-DMADMS was used as the raw material gas to form a fluidized film 131. The temperature of the substrate 100 during the formation of the fluidized film 131 was set to 24°C. After supplying the raw material gas and additive gas, an oxidizing gas (O2) was supplied into the processing container 10 to cure the fluidized film 131 and form the metal-containing film 132.

[0055] Reference Example 1 is the substrate 100 before step S12 is performed. That is, Reference Example 1 is a substrate 100 having a resist film 120. The resist film 120 in Reference Example 1 has a first aperture pattern.

[0056] Reference Example 2 is a substrate prepared using a conventional substrate processing method in which metal M contained in the raw material of the impregnation gas is impregnated into the resist film 120. The resist film 120 in Reference Example 2 has a first opening pattern. However, unlike Reference Example 1, the resist film 120 in Reference Example 2 contains metal M that has impregnated into the resist film 120. A gas containing bis-DMADMS was used as the impregnation gas. The temperature of the substrate 100 when supplying the impregnation gas was set to 120°C.

[0057] For each of these examples, the line CD (Critical Dimension), space CD, LER, and LWR were measured. Line CD is the line width of the film constituting each aperture pattern. Space CD is the aperture width of the aperture constituting each aperture pattern. LER indicates the magnitude of the irregularities formed on the surface of the film constituting each aperture pattern. LWR indicates the variation in the line width of the film due to the irregularities. Line CD and space CD were measured by contour extraction using length measurement software on the top-view observation image of the SEM (Scanning Electron Microscope). LER and LWR were measured by calculating the fluctuation from the straightness of the line CD and the variation in thickness, respectively.

[0058] The measurement results are shown in Table 1. Table 1 shows the values ​​for line CD, space CD, LER, and LWR, along with the line CD ratio in LER and the line CD ratio in LWR. The line CD ratio in LER is the percentage of LER to line CD for each film in Example 1, Reference Example 1, and Reference Example 2 ([LER / line CD] × 100). The line CD ratio in LWR is the percentage of LWR to line CD for each film in Example 1, Reference Example 1, and Reference Example 2 ([LWR / line CD] × 100).

[0059] [Table 1]

[0060] As shown in Table 1, the LER and LWR in Example 1 were reduced compared to Reference Examples 1 and 2. Furthermore, the line CD ratio in the LER and LWR of Example 1 were also reduced compared to Reference Examples 1 and 2. These results confirm that the roughness of the second opening pattern in Example 1 was improved compared to the roughness of the first opening pattern in Reference Examples 1 and 2.

[0061] (Processing system) Referring to Figure 5, an example of a processing system PS for carrying out the substrate processing method according to the embodiment will be described.

[0062] The processing system PS comprises processing units PM1 to PM4, vacuum transport chambers VTM, load lock chambers LL1 to LL3, atmospheric transport chamber LM, load ports LP1 to LP3, and a main control unit CU. In the example shown in Figure 5, the processing system PS is described as comprising multiple processing units PM1 to PM4, multiple load lock chambers LL1 to LL3, and multiple load ports LP1 to LP3, but the number of processing units, load lock chambers, and load ports is not limited to this. Furthermore, the processing system PS may also comprise multiple vacuum transport chambers VTM and / or atmospheric transport chambers LM.

[0063] Processing units PM1 to PM4 are connected to the vacuum transfer chamber VTM via gate valves G11 to G14, respectively. Processing units PM1 to PM4 are configured to reduce the internal pressure to a predetermined level. Processing units PM1 to PM4 house the substrate 100 inside and perform the desired processing.

[0064] The vacuum transport chamber VTM is configured to allow the internal pressure to be reduced to a predetermined level. The vacuum transport chamber VTM is equipped with a first transport device TR1 capable of transporting the substrate 100 under reduced pressure. The first transport device TR1 transports the substrate 100 to the processing units PM1 to PM4 and the load lock chambers LL1 to LL3. The first transport device TR1 has, for example, two transport arms FK11 and FK12 that can move independently.

[0065] Load lock chambers LL1 to LL3 are connected to the vacuum transport chamber VTM via gate valves G21 to G23, respectively. Load lock chambers LL1 to LL3 are also connected to the atmospheric transport chamber LM via gate valves G31 to G33, respectively. Load lock chambers LL1 to LL3 are configured to allow switching between an atmospheric and a vacuum environment inside.

[0066] The atmospheric transport chamber LM has an atmospheric environment inside. Inside the atmospheric transport chamber LM, for example, a downflow of clean air is formed. An aligner AN for aligning the substrate 100 is provided inside the atmospheric transport chamber LM. The aligner AN may be provided outside the atmospheric transport chamber LM. A second transport device TR2 is provided in the atmospheric transport chamber LM. The second transport device TR2 transports the substrate 100 to the load lock chambers LL1 to LL3, load ports LP1 to LP3 and the aligner AN.

[0067] Load ports LP1 to LP3 are provided on the long side walls of the atmospheric transport chamber LM. Carriers C are attached to load ports LP1 to LP3. Carrier C includes a carrier C containing the substrate 100 and an empty carrier C. Carrier C may be, for example, a FOUP (Front Opening Unified Pod).

[0068] The central control unit (CU) may be, for example, a computer. The central control unit (CU) comprises a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), and auxiliary storage. The CPU operates based on programs stored in the ROM or auxiliary storage and controls each part of the processing system PS. For example, the central control unit (CU) controls the operation of processing units PM1 to PM4, the first transport device TR1, the second transport device TR2, and gate valves G11 to G14, G21 to G23, and G31 to G33. For example, the central control unit (CU) controls the operation of switching the inside of load lock chambers LL1 to LL3 between an atmospheric atmosphere and a vacuum atmosphere.

[0069] Next, we will explain the operation of the processing system PS.

[0070] First, the second transport device TR2 removes the substrate 100 from the carrier C, transports the removed substrate 100 to the aligner AN, and exits from the aligner AN. Next, the aligner AN aligns the substrate 100. Then, the second transport device TR2 removes the substrate 100 from the aligner AN, transports the removed substrate 100 to the load lock chamber LL1, and exits from the load lock chamber LL1. Next, the atmosphere inside the load lock chamber LL1 is switched from an atmospheric atmosphere to a vacuum atmosphere. After that, the first transport device TR1 removes the substrate 100 from the load lock chamber LL1 and loads the removed substrate 100 into the processing device PM1. When the first transport device TR1 loads the substrate 100 into and out of the processing device PM1, the pressure inside the vacuum transport chamber VTM is adjusted to exceed the pressure inside the processing device PM1. For example, the flow rate of the inert gas flowing into the vacuum transport chamber VTM is adjusted so that the pressure inside the vacuum transport chamber VTM exceeds the pressure inside the processing device PM1. The same applies when loading and unloading the substrate 100 to processing units PM2 to PM4.

[0071] The processing apparatus PM1 performs a first process on the substrate 100. Here, the first process is a film deposition process in which a metal-containing film 132 is deposited on the substrate 100. The processing apparatus PM1 is a film deposition apparatus that performs a film deposition process on the substrate 100 by, for example, the CVD (Chemical Vapor Deposition) method. In the processing apparatus PM1, for example, step S12 shown in Figure 1 is performed.

[0072] Next, the first transport device TR1 removes the substrate 100 from the processing device PM1 and transports the removed substrate 100 to the processing device PM2.

[0073] The processing apparatus PM2 performs a second process on the substrate 100. The second process is, for example, an etching process to remove the metal-containing film 132 above the resist film 120 on the substrate 100. In the processing apparatus PM2, for example, step S13 shown in Figure 1 is performed.

[0074] Next, the first transport device TR1 removes the substrate 100 from the processing device PM2 and loads the removed substrate 100 into the processing device PM3.

[0075] The processing apparatus PM3 performs a third process on the substrate 100. The third process is, for example, an etching process to remove the resist film 120 on the substrate 100. In the processing apparatus PM3, for example, step S14 shown in Figure 1 is performed.

[0076] Next, the first transport device TR1 removes the substrate 100 from the processing device PM3, transports the removed substrate 100 to the load lock chamber LL3, and exits from the load lock chamber LL3. Then, the atmosphere inside the load lock chamber LL3 is switched from a vacuum to an atmospheric atmosphere. After that, the second transport device TR2 removes the substrate 100 from the load lock chamber LL3 and places the removed substrate 100 into the carrier C.

[0077] The processing apparatus PM4 may be a processing apparatus that performs the same processing as any of the processing apparatuses PM1 to PM3. Alternatively, the processing apparatus PM4 may be a processing apparatus that performs a fourth processing on the substrate 100 that is different from that performed by the processing apparatuses PM1 to PM3. The fourth processing may be performed before the first processing, after the first processing but before the second processing, after the second processing but before the third processing, or after the third processing. For example, after the third processing is performed by the processing apparatus PM3, a processing to etch a part of the underlayer film 110 using the metal-containing film 132 having the second aperture pattern as a mask may be performed (see Figure 2(g)).

[0078] Figure 5 shows processing units PM1 to PM4 connected via a vacuum transport chamber VTM of a single processing system PS, but at least one of the processing units PM1 to PM4 may be provided independently of the other processing units PM1 to PM4. For example, processing unit PM1, which performs the first processing, may be provided independently of the processing units PM2 to PM4. In this case, at the stage when the film deposition process by processing unit PM1 is completed (for example, when step S12b is completed), the substrate 100 may be transported outside of processing unit PM1. Alternatively, the substrate 100 transported outside of processing unit PM1 may pass through the vacuum transport chamber VTM and the atmospheric transport chamber LM, and then be transferred to another processing unit such as processing unit PM2 via a carrier C attached to the atmospheric transport chamber LM. The substrate 100 is then processed by the other processing unit such as processing unit PM2, to which it has been transferred, and subsequent processing is performed on the substrate 100.

[0079] [Substrate processing equipment] Next, the processing apparatus PM1 (hereinafter referred to as the substrate processing apparatus PM1) that performs the first treatment (film deposition treatment) on the substrate 100 will be described with reference to Figure 6. Figure 6 is a diagram showing an example of the substrate processing apparatus PM1 that performs the film deposition treatment on the substrate 100.

[0080] The substrate processing apparatus PM1 includes a processing container 10, a mounting table 20, a first gas supply unit 30, a first temperature control unit 40, and a control unit 50. The first gas supply unit 30 is an example of a "raw material gas supply unit" and a "purge gas supply unit". The substrate processing apparatus PM1 may further include a second gas supply unit 60, a second temperature control unit 70, an exhaust unit 80, a pressure detection unit 91, a first temperature detection unit 92, and a second temperature detection unit 93. The second gas supply unit 60 is an example of an "additive gas supply unit" and an "oxidizing gas supply unit".

[0081] The processing container 10 is equipped with an outer wall 11 that partitions the internal processing chamber. The outer wall 11 has, for example, a side wall 111, a bottom wall 112, and a top wall 113. The side wall 111 of the processing container 10 is provided with an opening (not shown) for transporting the substrate 100. The opening is opened and closed by a gate valve G11.

[0082] The mounting stage 20 is placed inside the processing container 10. The mounting stage 20 is configured to support the substrate 100. When placed on the mounting stage 20, the substrate 100 has a base film 110 and a resist film 120 placed on the base film 110 and having a first opening pattern, as shown in Figure 2(a). As the material for the mounting stage 20, for example, ceramic materials such as silicon carbide and aluminum nitride can be used.

[0083] The first gas supply unit 30 is configured to supply a raw material gas containing a metal-containing precursor into the processing container 10. As shown in Figure 6, the first gas supply unit 30 includes a raw material gas supply source 31 containing the metal-containing precursor, a supply pipe 32 which is the flow path for the raw material gas, a flow controller 33 which controls the flow rate of the raw material gas, and a valve 34 which opens and closes the supply pipe 32.

[0084] The first gas supply unit 30 may be configured to supply purge gas into the processing container 10. The first gas supply unit 30 may include a supply pipe 35 which is a flow path for the purge gas, a flow path switching valve 36 connected to the supply pipes 32 and 35, a supply pipe 37 located downstream of the flow path switching valve 36, and a valve 38 for opening and closing the supply pipe 37. The supply pipe 35 is connected to a purge gas supply source (not shown). The flow path switching valve 36 is configured to switch the fluid flowing through the supply pipe 37 from the raw material gas and the purge gas. The supply pipe 37 is connected to the processing container 10, for example, through a gas supply port 122a provided in the bottom wall 112 of the processing container 10. Note that the connection position between the supply pipe 37 and the processing container 10 (i.e., the connection position between the first gas supply unit 30 and the processing container 10) is not limited to the bottom wall 112. The connection position between the supply pipe 37 and the processing container 10 may be the side wall 111 or the top wall 113.

[0085] In Figure 6, the raw material gas and the purge gas are supplied into the processing container 10 through the same gas supply unit (first gas supply unit 30). However, the raw material gas and the purge gas may be supplied into the processing container 10 through different gas supply units.

[0086] The first temperature control unit 40 adjusts the temperature of the mounting table 20. By adjusting the temperature of the mounting table 20 by the first temperature control unit 40, the temperature of the substrate 100 is adjusted. The first temperature control unit 40 may be, for example, a refrigerant flow path that circulates a low-temperature refrigerant supplied from a chiller to cool the mounting table 20. This allows the substrate 100 placed on the mounting table 20 to be cooled to a temperature lower than the boiling point of the metal-containing precursor. The first temperature control unit 40 adjusts the temperature of the mounting table 20 in accordance with a control signal from the control unit 50.

[0087] The second gas supply unit 60 is configured to supply additive gas and oxidizing gas into the processing container 10. As shown in Figure 6, the second gas supply unit 60 has a supply pipe 61 which is a flow path for the additive gas and oxidizing gas, and a valve 62 which opens and closes the supply pipe 61. The second gas supply unit 60 may also have a flow rate controller (not shown) for controlling the flow rates of the additive gas and oxidizing gas. The supply pipe 61 is connected to a supply source for the additive gas (not shown) and a supply source for the oxidizing gas (not shown). The supply pipe 61 is connected to the processing container 10, for example, through a gas supply port 112b provided in the bottom wall 112 of the processing container 10. Note that the connection position between the supply pipe 61 and the processing container 10 (i.e., the connection position between the second gas supply unit 60 and the processing container 10) is not limited to the bottom wall 112. The connection position between the supply pipe 61 and the processing container 10 may be the side wall 111 or the top wall 113.

[0088] In Figure 6, the additive gas and the oxidizing gas are supplied into the processing container 10 through the same gas supply unit (second gas supply unit 60). However, the additive gas and the oxidizing gas may be supplied into the processing container 10 through different gas supply units.

[0089] The second temperature control unit 70 adjusts the temperature of the outer wall 11 of the processing container 10. The second temperature control unit 70 is, for example, a heater that heats the outer wall 11. This allows the outer wall 11 to be heated, which suppresses the adhesion of the fluidized film 131 to the outer wall 11 when the raw material gas is supplied into the processing container 10. The second temperature control unit 70 adjusts the temperature of the outer wall 11 in accordance with the control signal from the control unit 50.

[0090] The exhaust unit 80 includes a pressure regulating valve 81 and a vacuum pump 82. The exhaust unit 80 is connected to the processing container 10 through an exhaust port 113a provided in the top wall 113 of the processing container 10. The exhaust unit 80 adjusts the pressure inside the processing container 10 to a desired level in response to a control signal from the control unit 50. Note that the connection location between the exhaust unit 80 and the processing container 10 is not limited to the top wall 113. The connection location between the exhaust unit 80 and the processing container 10 may be the side wall 111 or the bottom wall 112.

[0091] The pressure detection unit 91 is a sensor that detects the pressure inside the processing container 10. The pressure detection unit 91 is provided, for example, in the exhaust unit 80. The first temperature detection unit 92 is a sensor that detects the temperature of the mounting base 20. The first temperature detection unit 92 is provided, for example, in the mounting base 20. The second temperature detection unit 93 is a sensor that detects the temperature of the outer wall 11 of the processing container 10. The second temperature detection unit 93 is provided, for example, in the outer wall 11. When describing the pressure detection unit 91, the first temperature detection unit 92, and the second temperature detection unit 93 without distinction, they may be collectively referred to as "each detection unit".

[0092] The control unit 50 is, for example, a computer and includes a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), auxiliary storage device, etc. The CPU operates based on a program stored in the ROM or auxiliary storage device and controls the operation of the substrate processing device PM1. The control unit 50 may be located inside or outside the substrate processing device PM1. If the control unit 50 is located outside the substrate processing device PM1, the control unit 50 can control the substrate processing device PM1 by communication means such as wired or wireless.

[0093] The control unit 50 controls the first gas supply unit 30, the first temperature adjustment unit 40, the second gas supply unit 60, and the exhaust unit 80 to execute step S12 shown in Figure 1. The control unit 50 may also further control the second temperature adjustment unit 70 to execute step S12.

[0094] The control unit 50 is configured to control the first temperature adjustment unit 40 so that the temperature of the substrate 100 placed on the mounting table 20 is lower than the boiling point of the metal-containing precursor. This makes it possible to form a conformal fluid film 131 and a metal-containing film 132.

[0095] When controlling the first temperature adjustment unit 40, the control unit 50 may acquire information from each detection unit and ROM regarding the pressure inside the processing container 10, the boiling point of the metal-containing precursor under the pressure inside the processing container 10, and the temperature of the mounting stage 20. The control unit 50 may also determine, based on the acquired information, whether the temperature of the substrate 100 is lower than the boiling point of the metal-containing precursor. In this case, the control unit 50 may consider the temperature of the mounting stage 20 to be the temperature of the substrate 100. Alternatively, the control unit 50 may, for example, refer to information stored in the ROM that shows the correspondence between the temperature of the mounting stage 20 and the temperature of the substrate 100, and convert the temperature of the substrate 100 from the temperature of the mounting stage 20.

[0096] The control unit 50 may be configured to control the second temperature adjustment unit 70 so that the temperature of the outer wall 11 of the processing container 10 is above the boiling point of the metal-containing precursor. This reduces the adhesion of the fluidized film 131 to the outer wall 11.

[0097] When controlling the second temperature adjustment unit 70, the control unit 50 may acquire information from each detection unit and ROM regarding the pressure inside the processing container 10, the boiling point of the metal-containing precursor under the pressure inside the processing container 10, and the temperature of the outer wall 11. The control unit 50 may also determine, based on the acquired information, whether the temperature of the outer wall 11 is above the boiling point of the metal-containing precursor.

[0098] The control unit 50 performs, for example, the following steps:

[0099] (a) A step of preparing a substrate 100 having a base film 110 and a resist film 120 disposed on the base film 110 and having a first opening pattern.

[0100] (b) A step of supplying a raw material gas containing a metal-containing precursor to fill the opening 120r of the first opening pattern with a flowable film 131 containing the metal contained in the metal-containing precursor at a temperature lower than the boiling point of the metal-containing precursor. Subsequently, a step of forming a metal-containing film 132 in the opening 120r by curing the flowable film 131.

[0101] In step (a), the control unit 50 controls the gate valve G11 and the first transport device TR1 to load the substrate 100 into the processing container 10, and places the substrate 100 on the mounting table 20. Alternatively, in step (a), after placing the substrate 100 on the mounting table 20, the control unit 50 may control the gate valve G11 and the first transport device TR1 to unload the substrate 100 from the processing container 10.

[0102] In step (b), the control unit 50 controls the first temperature control unit 40 to cool the substrate 100. In step (b), the control unit 50 also controls the valve 34, the flow path switching valve 36, and the valve 38 to supply raw material gas into the processing container 10. In step (b), the control unit 50 may also control the valve 62 to supply oxidizing gas into the processing container 10. At this time, the control unit 50 may also supply additive gas into the processing container 10. In step (b), the control unit 50 may also control the flow path switching valve 36 and the valve 38 to supply purge gas into the processing container 10. In step (b), the control unit 50 may also control the gate valve G11 to open and remove the substrate 100 from the processing container 10.

[0103] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The above embodiments may be omitted, replaced, or modified in various ways without departing from the scope and spirit of the appended claims. [Explanation of symbols]

[0104] 100 circuit boards 110 Undercoat 120 Resist film 131 Fluidized membrane 132 Metal-containing film

Claims

1. (a) A step of preparing a substrate having a base film and a resist film disposed on the base film and having a first opening pattern, (b) A step of supplying a raw material gas containing a metal-containing precursor to fill the openings of the first opening pattern with a flowable film containing the metal contained in the metal-containing precursor at a temperature lower than the boiling point of the metal-containing precursor, and then curing the flowable film to form a metal-containing film on the openings, (c) A step of removing the resist film and forming the metal-containing film having a second opening pattern that is the inverse of the first opening pattern, Having, Substrate processing method.

2. The aforementioned metal-containing precursor is an aminometal compound. The substrate processing method according to claim 1.

3. The amino metal compound includes, as the metal, at least one of silicon, germanium, hafnium, tin, titanium, zirconium, tungsten, and aluminum. The substrate processing method according to claim 2.

4. (d) A step between step (b) and step (c) further comprising the step of removing the metal-containing film on the resist film to expose the resist film, A substrate processing method according to any one of claims 1 to 3.

5. Processing container and A mounting platform disposed within the processing container, configured to place a substrate having a base film and a resist film disposed on the base film and having a first opening pattern, A raw material gas supply unit that supplies a raw material gas containing a metal-containing precursor into the processing container, A first temperature adjustment unit adjusts the temperature of the mounting platform, Control unit and Equipped with, The control unit, The process involves supplying a raw material gas containing the metal-containing precursor to fill the openings of the first opening pattern with a flowable film containing the metal contained in the metal-containing precursor at a temperature lower than the boiling point of the metal-containing precursor, and then curing the flowable film to form a metal-containing film on the openings. The first temperature control unit is configured to control the temperature of the substrate placed on the mounting base so that it is lower than the boiling point of the metal-containing precursor. Circuit board processing equipment.

6. The processing container further includes a second temperature adjustment unit for adjusting the temperature of the outer wall of the processing container, The control unit is configured to control the second temperature adjustment unit so that the temperature of the outer wall becomes equal to or equal to the boiling point of the metal-containing precursor. The substrate processing apparatus according to claim 5.

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