Substrate and substrate processing method

Abstract

To provide a substrate and a substrate processing method, enabling oxidation of a photoresist film in exposure.SOLUTION: This substrate has a photoresist film and an organic film. The photoresist film contains a first metal oxide and is sensitive to extreme ultraviolet (EUV) light. The organic film is formed beneath the photoresist film, has a lower binding energy between a metal and oxygen than that of the first metal oxide constituting the photoresist film, and contains a second metal oxide from which oxygen is dissociated by EUV light.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] Various aspects and embodiments of the present disclosure relate to substrates and substrate processing methods.

Background Art

[0002] Patent Document 1 below discloses "a method for producing a patterning structure, the method including providing a substrate that receives a pattern, incorporating a radiation absorption layer on the surface of the substrate, and providing an imaging layer, wherein the radiation absorption layer is under the imaging layer so as to increase the radiation absorption rate and / or patterning performance of the imaging layer".

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Non-Patent Documents

[0004]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The present disclosure provides a substrate and a substrate processing method capable of realizing oxidation of a photoresist film in exposure.

Means for Solving the Problem

[0006] A substrate according to one aspect of the present disclosure has a photoresist film and an organic film. The photoresist film contains a first metal oxide and reacts with EUV (Extreme Ultra Violet) light. The organic film is formed under the photoresist film and contains a second metal oxide having a lower metal-oxygen bond energy than the first metal oxide constituting the photoresist film and from which oxygen is dissociated by EUV light.

Advantages of the Invention

[0007] According to the present disclosure, oxidation of the photoresist film can be achieved in exposure.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Embodiments for Carrying Out the Invention

[0009] Hereinafter, embodiments of the substrate and the substrate processing method disclosed in the present application will be described in detail with reference to the drawings. Note that the disclosed substrate and substrate processing method are not limited by this embodiment.

[0010] In the manufacture of semiconductor devices, patterns are formed on a substrate such as a semiconductor wafer by a lithography process. In the lithography process, a photoresist film is formed on the surface of the substrate. Then, in the lithography process, selective exposure is performed on the formed photoresist film through a mask having a predetermined pattern formed thereon, and a development process is performed to form a pattern of a predetermined shape on the photoresist film. Conventionally, a carbon-based photoresist has been used for the photoresist film. For example, conventionally, a chemically amplified resist has been used for the photoresist film.

[0011] In recent years, with the miniaturization of semiconductor devices, miniaturization has also progressed in lithography technology. As a miniaturization technique, shortening the wavelength of the exposure light source can be mentioned. In recent years, EUV (Extreme Ultra Violet) exposure using EUV light has been performed.

[0012] By the way, a conventional carbon-based photoresist film has poor EUV absorption and takes time for the reaction. Therefore, in EUV exposure, a photoresist film containing a metal oxide is used. For example, in EUV exposure, a metal oxide resist (MOR) such as tin oxide is used for the photoresist film.

[0013] Here, Non-Patent Document 1 shows the EUV absorption cross-section of atoms. FIG. 1 is a diagram showing the EUV absorption cross-section of atoms. The horizontal axis of FIG. 1 is the atomic number of each atom. The horizontal axis of FIG. 1 is the atomic absorption cross-section. The absorption cross-section indicates the ratio of EUV absorbed when it passes through an atom. In FIG. 1, for each atomic number, the absorption cross-section of the atom with that atomic number is shown. For example, the absorption cross-section of atomic number 12 is the absorption cross-section of carbon. The absorption cross-section of atomic number 50 is the absorption cross-section of tin. Tin has a larger EUV absorption cross-section than carbon. That is, tin has a higher EUV absorption rate than carbon.

[0014] In EUV lithography, a substrate with a photoresist film formed thereon is transported to an EUV exposure apparatus, and EUV light is irradiated onto the photoresist film in the EUV exposure apparatus for exposure. Then, the substrate is taken out of the EUV exposure apparatus and PEB (Post Exposure Bake) is performed. In PEB, by heat-treating the substrate that has been subjected to EUV exposure, the reaction of the exposed portion of the photoresist film with oxygen is promoted.

[0015] Here, for the photoresist film, oxidation immediately after exposure is desirable due to its development mechanism. However, since the EUV exposure apparatus performs EUV exposure of the substrate with a high vacuum inside, it is difficult to flow a gas that promotes oxidation, and oxidation of the photoresist film does not progress during exposure. If oxidation of the photoresist film can be realized during exposure, usually, oxygen is supplied to the photoresist film by PEB or the like after exposure, but oxidation of the photoresist film can be realized by in-situ treatment in the chamber of the EUV exposure apparatus. Also, if a metal oxide binds to the photoresist film, it becomes an anchor and the adhesion is also improved.

[0016] Therefore, a technique for realizing oxidation of the photoresist film during exposure is provided.

[0017] (Embodiment) An embodiment will be described. First, an example of the substrate 10 used for substrate processing according to the embodiment will be described. FIG. 2 is a diagram for explaining an example of the substrate 10 according to the embodiment. In FIG. 2, the substrate 10 is shown. On the silicon substrate 11, a first lower layer film 12, a second lower layer film 13, and an organic film 14 are laminated in this order. The first lower layer film 12 is, for example, SOC (Spin On Carbon) or low-density a-C (amorphous carbon). The second lower layer film 13 is, for example, an organic film, SiC, SiON, or SiOCN. The organic film 14 is, for example, DLC (diamond-like carbon), a-C (amorphous carbon), etc. The organic film 14 is a film that serves as an underlayer for the photoresist film described later. Note that the first lower layer film 12, the second lower layer film 13, and the organic film 14 are not limited to the above-described examples. Also, the configuration of the substrate 10 shown in FIG. 2 is an example and is not limited thereto. On the substrate 10, films necessary for manufacturing a semiconductor device are formed as required.

[0018] When manufacturing a semiconductor device, a pattern is formed on the substrate 10 by a lithography process. In the lithography process, a photoresist film containing a metal oxide is formed on the surface of the substrate 10. The metal oxide is an oxide of any one of Sn (tin), W (tungsten), Te (tellurium), Sb (antimony), In (indium), Zn (zinc), Zr (zirconium), In (indium), Hf (hafnium). For example, in EUV exposure, a metal oxide resist film 20 is formed as a photoresist film on the surface of the substrate 10. For example, on the substrate 10, a tin oxide film is formed as the metal oxide resist film 20.

[0019] In EUV exposure, the substrate 10 on which such a metal oxide resist film 20 is formed is transported to an EUV exposure apparatus, and EUV light is irradiated onto the metal oxide resist film 20 in the EUV exposure apparatus for exposure. Since the EUV exposure apparatus performs EUV exposure with a high vacuum inside, it is difficult to flow a gas that promotes oxidation, and the reaction of the exposed portion of the metal oxide resist film 20 with oxygen does not proceed.

[0020] Therefore, in the substrate 10 according to the embodiment, the organic film 14 contains a metal oxide in which the bond energy between metal and oxygen is lower than that of the metal oxide contained in the metal oxide resist film 20, and oxygen is dissociated by EUV light. For example, when the metal oxide resist film 20 is a tin oxide (SnOx) film, the organic film 14 contains a metal oxide in which the bond energy between metal and oxygen is lower than that of tin oxide, and oxygen is dissociated by EUV light. Examples of the metal oxide contained in the organic film 14 include oxides of Cs (cesium) (CsOx), oxides of Te (tellurium) (TeOx), oxides of Se (selenium) (SeOx), and the like.

[0021] Figure 3 is a diagram for explaining the case where the substrate 10 according to the embodiment is subjected to EUV exposure. FIG. 3 shows the organic film 14 and the metal oxide resist film 20 portions of the substrate 10 according to the embodiment. The metal oxide resist film 20 contains a compound (Sn-R) of Sn and a ligand (R) such as CHx. When the substrate 10 according to the embodiment is subjected to EUV exposure, Sn and the ligand (R) are cut at the exposed portion of the metal oxide resist film 20. In addition, secondary electrons are generated from metal oxides (MeO) such as CsOx, TeOx, and SeOx contained in the organic film 14, and a part of them is supplied to the metal oxide resist film 20 to assist the reaction of the metal oxide resist film 20. Further, when the substrate 10 according to the embodiment is subjected to EUV exposure, oxygen is dissociated from the metal oxide of the organic film 14, and the reaction of oxygen in the exposed portion of the metal oxide resist film 20 proceeds. For example, in the exposed portion of the metal oxide resist film 20, oxygen is supplied from the metal oxide (MeO) contained in the organic film 14, and a reaction as shown in Chemical Formula (1) occurs. Also, at the interface portion between the metal oxide resist film 20 and the organic film 14, a reaction as shown in Chemical Formula (2) occurs together with Chemical Formula (1), and the metal oxide and the resist are bonded to form an anchor, improving the adhesion.

[0022]

Chemical formula

[0023] By including the metal oxide in the organic film 14 in this way, oxidation of the metal oxide resist film 20 can be achieved in exposure for the substrate 10 according to the embodiment.

[0024] The higher the content rate of the metal oxide in the organic film 14, the greater the amount of secondary electrons and oxygen generated by EUV exposure. However, when the content rate of the metal oxide in the organic film 14 increases, the properties of the metal oxide appear and the properties as an organic film deteriorate. For this reason, the content rate of the metal oxide in the organic film 14 is preferably 1 to 20 Atomic%, and more preferably 5 to 10 Atomic%.

[0025] Also, when EUV exposure is performed, secondary electrons and oxygen generated in the portion of the organic film 14 close to the metal oxide resist film 20 reach the metal oxide resist film 20. For this reason, the metal oxide in the organic film 14 may be unevenly distributed on the metal oxide resist film 20 side. For example, the metal oxide may be unevenly distributed in the range of 20 nm from the interface of the organic film 14 with the metal oxide resist film 20, and more preferably in the range of 5 nm.

[0026] FIG. 4 is a diagram for explaining an example in the case of unevenly distributing the metal oxide in the organic film 14 of the substrate 10 according to the embodiment. In FIG. 4, the metal oxide 14a contained in the organic film 14 is schematically shown. Further, FIG. 4 shows the concentration distribution of the metal oxide 14a with respect to the depth from the interface with the metal oxide resist film 20. In FIG. 4, the case where the concentration of the metal oxide 14a gradually increases on the interface side and reaches a maximum of 10 Atomic% in the range of 5 nm from the interface between the metal oxide resist film 20 and the organic film 14 is shown.

[0027] In this way, by unevenly distributing the metal oxide on the metal oxide resist film 20 side of the organic film 14, oxidation of the metal oxide resist film 20 can be achieved in exposure while maintaining the function of the organic film 14.

[0028] The oxides of Cs, Te, and Se have different ease of oxygen dissociation depending on the oxidized valence. Therefore, for the oxides of Sn and Cs, Te, and Se, the Gibbs free energy was calculated to verify whether the oxidation reaction occurs. FIG. 5 is a diagram showing an example of the verification result according to the embodiment. In FIG. 5, Cs 2 O, Cs 2 O 2 、Cs 2 O 3 、CsO 2 、CsO 3 、TeO, TeO 2 、TeO 3 、SeO 2 、SeO 3 show the Gibbs free energy when Sn is reacted with SnO 2 and when SnO is reacted with SnO 2 . When the Gibbs free energy is a negative value, the reaction of oxidizing Sn occurs. For example, Cs 2 O 2 、Cs 2 O 3 、CsO 2 、CsO 3 、TeO, TeO 2 、TeO 3 、SeO 2 、SeO 3 can react Sn with SnO 2 and can also react SnO with SnO 2 . That is, when the metal oxide resist film 20 is a tin oxide film, the metal oxide contained in the organic film 14 is preferably any of the divalent or higher oxides of Cs, the oxides of Te, and the oxides of Se.

[0029] The metal oxide contained in the organic film 14 is preferably stable within the organic film 14. Here, the stability of the oxide of Cs will be explained. Cs 2 O, Cs 2 O 2 、Cs 2 O 3 、CsO 2 are stable at room temperature. On the other hand, CsO 3 is CsO at room temperature 2gradually decomposes. Therefore, when using an oxide of Cs as the metal oxide contained in the organic film 14, the metal oxide is preferably one of Cs 2 O 2 、Cs 2 O 3 、CsO 2 .

[0030] (Device Configuration) Next, an example of the configuration of a film forming apparatus 100 for forming the organic film 14 according to the embodiment will be described. FIG. 6 is a diagram showing an example of the schematic configuration of the film forming apparatus 100 according to the embodiment.

[0031] The film forming apparatus 100 includes a grounded cylindrical vacuum chamber 101 made of, for example, aluminum. A susceptor 102 for placing the substrate 10 is provided at the bottom of the vacuum chamber 101. The susceptor 102 is made of, for example, aluminum and is formed in a substantially cylindrical shape. The susceptor 102 also functions as a lower electrode of a parallel plate electrode. An electrostatic chuck 103 is provided on the upper surface of the susceptor 102. The electrostatic chuck 103 is configured by embedding an electrode 131 in a thin dielectric layer. The electrode 131 is connected to a DC voltage source 133 via a switch 132. The electrostatic chuck 103 electrostatically adsorbs the substrate 10 when the switch 132 is turned on and a DC voltage is applied from the DC voltage source 133 to the electrode 131. A plurality of holes 134 for heat transfer gas are formed in the electrostatic chuck 103. A heat transfer gas (for example, helium gas) from a heat transfer gas supply pipe 135 is supplied to the holes 134. The electrostatic chuck 103 is configured to supply the heat transfer gas supplied from the heat transfer gas supply pipe 135 to a minute gap between the substrate 10 and the electrostatic chuck 103 through the holes 134. Although not shown, a lifter pin for transferring the substrate 10 is provided which moves up and down through the electrostatic chuck 103 and the susceptor 102.

[0032] The susceptor 102 has a flow path 121 formed inside. The susceptor 102 has a refrigerant supply pipe 122 connected to one end of the flow path 121 and a refrigerant discharge pipe 123 connected to the other end of the flow path 121. The refrigerant supplied from the refrigerant supply pipe 122 is discharged from the refrigerant discharge pipe 123 through the flow path 121 of the susceptor 102. The temperature of the substrate 10 is adjusted, for example, by the cooling effect of the refrigerant and the heat transfer efficiency between the substrate 10 and the electrostatic chuck 103 by the heat transfer gas. A ring body 124 made of an insulating material is provided at the upper peripheral portion of the susceptor 102 to effectively inject reactive ions into the substrate 10.

[0033] The susceptor 102 is fitted into a flat cylindrical insulator 125 with an open upper surface so as to be insulated from the vacuum chamber 101. Then, a matcher 141 and a first high-frequency power supply 104 are connected between the susceptor 102, which is a lower electrode, and a reference potential, for example, ground. The first high-frequency power supply 104 is configured to generate high-frequency power LF for bias. The frequency of the high-frequency power LF may be the same as or different from the frequency of the high-frequency power HF for plasma generation described later. In one embodiment, the high-frequency power LF has a frequency lower than the frequency of the high-frequency power HF. In one embodiment, the high-frequency power HF has a frequency in the range of 100 kHz to 60 MHz.

[0034] An electrode plate 151 is provided on the ceiling portion of the vacuum chamber 101 so as to be parallel to and opposed to the susceptor 102. The electrode plate 151 constitutes the upper electrode of the parallel plate electrodes. The electrode plate 151 is a dielectric (for example, SiO 2) It is composed of aluminum coated by . A large number of gas supply holes 152 are provided in the electrode plate 151. The electrode plate 151 is supported by an electrode support 153 made of a conductor. A space is formed between the electrode plate 151 and the electrode support 153, and a gas diffusion plate 154 is arranged so as to divide the space into two upper and lower spaces. The gas diffusion plate 154 is provided with a plurality of gas holes 156. A gas supply pipe 106 is connected to the electrode support 153. The gas supply pipe 106 is connected to the electrode support 153 so as to supply a processing gas to the space between the electrode support 153 and the gas diffusion plate 154. The processing gas supplied from the gas supply pipe 106 diffuses and is supplied to the space between the electrode plate 151 and the gas diffusion plate 154 through the plurality of gas holes 156 of the gas diffusion plate 154. Then, the processing gas supplied to the space between the electrode plate 151 and the gas diffusion plate 154 is supplied to the processing space from the gas supply hole 152 of the electrode plate 151. The electrode plate 151 and the electrode support 153 are insulated from the vacuum container 101 by an insulator 155.

[0035] An impedance matcher 171 and a second high-frequency power supply 107 are connected between the electrode plate 151, which is the upper electrode, and a reference potential, for example, ground. The second high-frequency power supply 107 is configured to generate high-frequency power HF for plasma generation. In one embodiment, the high-frequency power HF has a frequency in the range of 10 MHz to 150 MHz.

[0036] A valve V is provided in the gas supply pipe 106. The gas supply pipe 106 is connected to a gas supply unit 160. The gas supply unit 160 is provided with at least one gas source capable of supplying various processing gases used for film formation. The gas source is connected to the gas supply pipe 106 via a flow controller. The flow controller may include, for example, a mass flow controller or a pressure-controlled flow controller. The gas supply unit 160 supplies various gases from each gas source to the gas supply pipe 106 via the flow controller.

[0037] An exhaust pipe 111 is connected to the bottom of the vacuum chamber 101. The exhaust pipe 111 is connected to a vacuum pump 112. The interior of the vacuum chamber 101 is evacuated by the vacuum pump 112 via the exhaust pipe 111.

[0038] Next, the process of forming the organic film 14 on the substrate 10 in the film forming apparatus 100 will be briefly described. Up to the second lower layer film 13 is formed on the substrate 10. The substrate 10 is carried into the vacuum chamber 101 maintained at a predetermined degree of vacuum in advance from a load lock chamber (not shown) adjacent to the vacuum chamber 101. Then, the substrate 10 is placed on the susceptor 102 through the lifting operation of a lifter pin (not shown). The susceptor 102 is adjusted to a predetermined temperature in advance. By turning on the switch 132 and applying a DC voltage to the electrode 131, the substrate 10 is adsorbed and held by the electrostatic chuck 103.

[0039] The film forming apparatus 100 opens the valve V, supplies various gases used for forming the organic film 14 from the gas supply pipe 106, and supplies high-frequency power HF and high-frequency power LF from the first high-frequency power supply 104 and the second high-frequency power supply 107 to form the organic film 14.

[0040] An example of the processing conditions for forming the organic film 14 is shown below. ·Processing conditions Temperature of the susceptor 102: 60 °C Pressure inside the vacuum chamber 101: 3 Pa Power of the high-frequency power HF: 400 W Power of the high-frequency power LF: Less than 60 W

[0041] ·First gas condition C 2 H 2 (10%)-containing Ar gas: 500 sccm (8.34×10 -6 m 3 / s) Ar gas: 80 sccm Processing time: 50 seconds

[0042] ·Second gas condition C2 H 2 (10%) Ar gas: 500 sccm Ar gas: 80 sccm Te(CH 3 ) 2 Gas: 0 → 5 sccm (increasing by 1 sccm per second) Processing time: 5 seconds

[0043] The film forming apparatus 100 starts forming the organic film 14 under the above processing conditions. In the film forming of the lower part of the organic film 14, various gases are supplied under the first gas conditions, and in the film forming of the upper part of the organic film 14, various gases are supplied under the second gas conditions, and metal oxides are unevenly distributed in the organic film 14 to form a film. Thereby, for example, as shown in FIG. 4, an organic film 14 with unevenly distributed metal oxides can be formed on the substrate 10.

[0044] The substrate 10 on which the organic film 14 is formed is carried out of the film forming apparatus 100 in the reverse procedure to the carrying-in. After the substrate 10 is carried out, the film forming apparatus 100 supplies oxygen gas from the gas supply pipe 106 to clean the inside of the vacuum chamber 101.

[0045] (Substrate processing) Next, an example of substrate processing including the substrate processing method of the present disclosure will be described. FIG. 7 is a diagram showing an example of the flow of substrate processing according to the embodiment. FIG. 8 is a diagram showing an example of the change in the substrate 10 by the substrate processing according to the embodiment. As shown in FIG. 8(A), the second lower layer film 13 is formed on the substrate 10.

[0046] An organic film 14 containing metal oxides is formed on the substrate 10 (step S10). For example, the substrate 10 is transported to the film forming apparatus 100, and the film forming apparatus 100 forms an organic film 14 containing divalent or higher oxides of Cs, oxides of Te, and oxides of Se as metal oxides on the second lower layer film 13 of the substrate 10. For example, the organic film 14 is formed with unevenly distributed metal oxides on the upper surface side as described above. Thereby, as shown in FIG. 8(B), an organic film 14 is formed on the second lower layer film 13 of the substrate 10.

[0047] Next, a photoresist film containing a metal oxide is formed on the substrate 10 (step S11). For example, the substrate 10 is transported to a film-forming apparatus, and a metal oxide resist film 20 such as a tin oxide film is formed on the substrate 10 by the film-forming apparatus. The metal oxide resist film 20 may be formed on the substrate 10 by spin coating or by vacuum film formation. As a result, as shown in FIG. 8(C), the metal oxide resist film 20 is formed on the organic film 14 of the substrate 10.

[0048] Next, EUV exposure is performed on the substrate 10 (step S12). For example, the substrate 10 is transported to an EUV exposure apparatus, and EUV exposure is performed on the substrate 10 by the EUV exposure apparatus. In EUV exposure, as shown in FIG. 8(D), EUV light is irradiated onto the metal oxide resist film 20 of the substrate 10 through a mask 30 having a predetermined pattern formed thereon. In the metal oxide resist film 20, an exposed portion 21a exposed to EUV light and an unexposed portion 21b not exposed to EUV light are formed corresponding to the mask 30, as shown in FIG. 8(E). When the organic film 14 is subjected to EUV exposure, secondary electrons are generated from the metal oxide of the exposed portion 21a, and oxygen dissociates from the metal oxide of the exposed portion 21a. As a result, in the metal oxide resist film 20, the reaction of oxygen in the exposed portion proceeds. In this way, the substrate 10 can achieve oxidation of the metal oxide resist film 20 during exposure.

[0049] After EUV exposure, PEB is performed on the substrate 10 (step S13). It is known that PEB generally performed in a photolithography process has an effect of promoting a chemical reaction caused by exposure. In the present embodiment, due to the characteristics of the chemical species used, it is desirable to perform the process at a set temperature higher than normal, in the range of 100 to 300°C. For example, by performing heat treatment stepwise at 180°C for 60 seconds and 250°C for 60 seconds, the reaction rate of the chemical reaction can be controlled more effectively even in a higher temperature range, and as a result, a desired pattern dimension can be formed with higher accuracy.

[0050] Next, development of the photoresist film is performed (step S14). For example, in the metal oxide resist film 20, an etching rate difference occurs between the exposed portion 21a and the unexposed portion 21b. By etching the metal oxide resist film 20 using the selection ratio between the exposed portion 21a and the unexposed portion 21a, the metal oxide resist film 20 is developed. For example, the substrate 10 is transferred to an etching apparatus, and the metal oxide resist film 20 on the substrate 10 is etched in the etching apparatus. As a result, the pattern formed in the metal oxide resist film 20 is developed. FIG. 8(F) shows a case where negative tone development is performed to leave the exposed portion 21a of the metal oxide resist film 20.

[0051] Thereafter, patterning processing is performed on the substrate 10 using the pattern of the metal oxide resist film 20 developed in this manner. For example, the first lower layer film 12, the second lower layer film 13, and the organic film 14 are etched using the pattern of the metal oxide resist film 20.

[0052] In the above-described embodiment, the case where the metal oxide resist film 20 is a tin oxide film has been mainly described as an example. However, the disclosed technology is not limited to this. The metal oxide resist film 20 may be any oxide of Sn, W, Te, Sb, In, Zn, Zr, In, or Hf. In this case, the metal oxide contained in the organic film 14 may be a metal oxide having a lower metal-oxygen bond energy than the metal oxide of the metal oxide resist film 20 and in which oxygen is dissociated by EUV light.

[0053] In the above-described embodiments, the case where the photoresist film is a metal oxide resist film 20 has been mainly described as an example. However, the disclosed technology is not limited to this. The photoresist film may be a film that contains a metal oxide and reacts to EUV light. For example, the photoresist film may be a chemically amplified resist containing a metal oxide. The metal oxide contained in the photoresist film is preferably a metal oxide having a high EUV absorption rate, and may be, for example, an oxide of any one of Sn, Sn, W, Te, Sb, In, Zn, Zr, In, and Hf.

[0054] The embodiments have been described above. As described above, the substrate 10 according to the above-described embodiments has a photoresist film and an organic film 14. The photoresist film contains a first metal oxide and reacts to EUV light. The organic film 14 is formed under the photoresist film and contains a second metal oxide having a lower metal-oxygen bond energy than the first metal oxide constituting the photoresist film and from which oxygen dissociates by EUV light. Thereby, the substrate 10 according to the embodiment can realize oxidation of the photoresist film during exposure.

[0055] Also, the photoresist film is a metal oxide resist film 20. Thereby, the substrate 10 according to the embodiment can realize oxidation of the metal oxide resist film 20 during exposure.

[0056] Also, the organic film 14 constitutes an underlayer of the metal oxide resist film 20. Thereby, the substrate 10 according to the embodiment can realize oxidation of the metal oxide resist film 20 during exposure.

[0057] Also, the second metal oxide is unevenly distributed on the organic film 14 side of the metal oxide resist film 20. Also, the second metal oxide is unevenly distributed in a range of 5 nm from the interface with the metal oxide resist film 20 in the organic film 14. Also, the concentration of the second metal oxide is higher closer to the interface with the metal oxide resist film 20 in the organic film 14. Thereby, the substrate 10 according to the embodiment can realize oxidation of the metal oxide resist film 20 during exposure while maintaining the function of the organic film 14.

[0058] Further, the first metal oxide is an oxide of Sn. The second metal oxide is any one of oxides of divalent or higher valent Cs, oxides of Te, and oxides of Se. The divalent or higher valent oxide of Cs is Cs 2 O 2 , Cs 2 O 3 , CsO 2 or the like. Thereby, the substrate 10 according to the embodiment can realize the oxidation of the oxide of Sn contained in the photoresist film in exposure.

[0059] (Others) Note that the technology disclosed in the present application is not limited to the above-described embodiments, and various modifications are possible within the scope of the gist.

[0060] It should be considered that the embodiments disclosed this time are illustrative in all respects and not restrictive. In fact, the above-described embodiments can be embodied in various forms. Further, the above embodiments may be omitted, replaced, or changed in various forms without departing from the scope and spirit of the appended claims.

[0061] Regarding the above embodiments, the following additional remarks are disclosed.

[0062] (Additional Remark 1) A substrate having a photoresist film containing a first metal oxide and reacting with EUV (Extreme Ultra Violet) light, and an organic film formed under the photoresist film and containing a second metal oxide having a lower metal-oxygen bond energy than the first metal oxide constituting the photoresist film and dissociating oxygen by EUV light.

[0063] (Additional Remark 2) The photoresist film is a metal oxide resist film The substrate according to Additional Remark 1.

[0064] (Additional Remark 3) The organic film constitutes an underlayer of the metal oxide resist film. The substrate according to Supplementary Note 2.

[0065] (Supplementary Note 4) In the organic film, the second metal oxide is unevenly distributed on the side of the metal oxide resist film. The substrate according to Supplementary Note 3.

[0066] (Supplementary Note 5) In the organic film, the second metal oxide is unevenly distributed in the range of 5 nm from the interface with the metal oxide resist film. The substrate according to Supplementary Note 4.

[0067] (Supplementary Note 6) In the organic film, the closer to the interface with the metal oxide resist film, the higher the concentration of the second metal oxide. The substrate according to Supplementary Note 4 or 5.

[0068] (Supplementary Note 7) The first metal oxide is an oxide of Sn. The substrate according to any one of Supplementary Notes 1 to 6.

[0069] (Supplementary Note 8) The second metal oxide is any one of a divalent or higher oxide of Cs, an oxide of Te, and an oxide of Se. The substrate according to Supplementary Note 7.

[0070] (Supplementary Note 9) The divalent or higher oxide of Cs is Cs 2 O 2 , Cs 2 O 3 , CsO 2 or any one of them. The substrate according to Supplementary Note 8.

[0071] (Supplementary Note 10) A substrate processing method that includes a first metal oxide and forms a pattern on a photoresist film that reacts to EUV (Extreme Ultra Violet) light. a) Forming a film on a substrate of an organic film containing a second metal oxide having a lower metal-oxygen bond energy than the first metal oxide and from which oxygen dissociates by EUV light; b) Forming the photoresist film on the organic film of the substrate; c) Irradiating the photoresist film with EUV light through a mask on which a predetermined pattern is formed; d) Heat-treating the photoresist film irradiated with EUV light; e) Developing the heat-treated photoresist film to form the pattern. A substrate processing method comprising the above steps.

Explanation of reference numerals

[0072] 10 Substrate 11 Silicon substrate 12 First lower layer film 13 Second lower layer film 14 Organic film 14a Metal oxide 20 Metal oxide resist film 30 Mask 100 Film forming apparatus

Claims

1. A substrate having a photoresist film containing a first metal oxide and reacting with extreme ultraviolet (EUV) light, and an organic film formed under the photoresist film, containing a second metal oxide having a lower metal-oxygen bond energy than the first metal oxide constituting the photoresist film and in which oxygen dissociates by EUV light.

2. The substrate according to claim 1, wherein the photoresist film is a metal oxide resist film.

3. The substrate according to claim 2, wherein the organic film constitutes an underlayer of the metal oxide resist film.

4. The substrate according to claim 3, wherein the second metal oxide is unevenly distributed on the side of the organic film closer to the metal oxide resist film.

5. The substrate according to claim 4, wherein the second metal oxide is unevenly distributed in a range of 5 nm from the interface with the metal oxide resist film.

6. The substrate according to claim 4, wherein the concentration of the second metal oxide is higher closer to the interface with the metal oxide resist film.

7. The substrate according to claim 1, wherein the first metal oxide is an oxide of Sn.

8. The substrate according to claim 7, wherein the second metal oxide is any one of a divalent or higher oxide of Cs, an oxide of Te, and an oxide of Se.

9. The substrate according to claim 8.

10. A substrate processing method for forming a pattern on a photoresist film containing a first metal oxide and reacting with extreme ultraviolet (EUV) light, the method comprising: a) forming, on a substrate, an organic film containing a second metal oxide having a lower metal-oxygen bond energy than the first metal oxide constituting the photoresist film and in which oxygen dissociates by EUV light; b) forming the photoresist film on the organic film of the substrate; c) irradiating the photoresist film with EUV light through a mask on which a predetermined pattern is formed; d) heat-treating the photoresist film irradiated with EUV light; and e) developing the heat-treated photoresist film to form the pattern. The divalent or higher oxide of Cs is Cs ２ O ２ , Cs ２ O ３ , CsO ２ or any of them ​ ​ ​ ​ ​ ​ ​ ​ ​

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