Method of forming resist pattern, method of manufacturing semiconductor device, substrate processing apparatus, and storage medium

Abstract

The invention provides a method of forming a resist pattern, a method of manufacturing a semiconductor device, a substrate processing apparatus, and a storage medium, capable of forming a resist pattern with high contrast in a case where a fine resist pattern is formed by EUV lithography. The method of forming a resist pattern includes, in this order: a step of irradiating a portion of a resist film containing a metal oxide resist material with extreme ultraviolet light; a step in which the resist film is irradiated with ultraviolet light having a wavelength of 100 nm or more in the entire region including the portion irradiated with the extreme ultraviolet light and the portions other than the portion irradiated with the extreme ultraviolet light; and a step of forming a resist pattern by development in which a part of the resist film is removed.

Description

Technical Field

[0001] The present invention relates to a method for forming a resist pattern, a method for manufacturing a semiconductor device, a substrate processing apparatus and a storage medium. Background Art

[0002] In order to form a fine resist pattern with a size of 20nm, the technology of extreme ultraviolet (EUV) lithography using chemically amplified resist materials has been applied in the past (Patent Document 1). In order to form a fine resist pattern by EUV lithography, the application of non-chemically amplified resist materials has been proposed (Patent Document 1 and Non-Patent Document 1).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: U.S. Patent Application Publication No. 2020 / 0064733

[0006] Non-patent literature 1: J. Micro / Nanolith. MEMS MOEMS 16(2), 023510 (Apr-Jun 2017) Summary of the invention

[0007] Technical problem to be solved by the invention

[0008] When forming a fine resist pattern by EUV lithography, it is desirable to form the resist pattern with high contrast.

[0009] Technical solutions for solving technical problems

[0010] One aspect of the present invention relates to a method for forming a resist pattern, which comprises, in sequence: a step of irradiating a portion of a resist film containing a resist material containing a metal oxide resist material with extreme ultraviolet rays; a step of irradiating the entire region of the resist film including the portion irradiated with the extreme ultraviolet rays and the portion other than the portion irradiated with ultraviolet rays having a wavelength of greater than 100 nm; and a step of forming a resist pattern by developing the resist film to remove a portion of the resist film.

[0011] Effects of the Invention

[0012] According to the method of the present invention, a fine resist pattern formed by extreme ultraviolet (EUV) lithography can be formed with high contrast. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a flowchart showing an example of a method for forming a resist pattern.

[0014] Figure 2The present invention is a process diagram showing an example of a method for manufacturing a semiconductor device by a method including forming a resist pattern.

[0015] Figure 3 The present invention is a process diagram showing an example of a method for manufacturing a semiconductor device by a method including forming a resist pattern.

[0016] Figure 4 The present invention is a process diagram showing an example of a method for manufacturing a semiconductor device by a method including forming a resist pattern.

[0017] Figure 5 This is a flowchart showing an example of a method for forming a resist pattern.

[0018] Figure 6 This is a flowchart showing an example of a method for forming a resist pattern.

[0019] Figure 7 It is a schematic diagram showing an example of a substrate processing apparatus.

[0020] Figure 8 It is a schematic diagram showing an example of a substrate processing apparatus.

[0021] Fig. 9 It is a schematic diagram which shows an example of an exposure unit.

[0022] Fig.10 This is a graph showing the relationship between the thickness of the resist film remaining after the development process and the EUV dose.

[0023] Fig.11 This is a graph showing the relationship between the thickness of the resist film remaining after the development process and the EUV dose.

[0024] Fig.12 This is a graph showing the relationship between the thickness of the resist film remaining after the development process and the EUV dose.

[0025] Fig.13 It is a graph showing the relationship between the line width (CD) of the resist pattern and the EUV dose.

[0026] Fig.14 This is a graph showing the relationship between line width roughness (LWR) and line width (CD) of a resist pattern.

[0027] Fig.15 This is a graph showing the relationship between the number of defects and the line width (CD) of the resist pattern.

[0028] Fig.16 It is a graph showing the relationship between the line width (CD) of the resist pattern and the EUV dose.

[0029] Fig.17This is a graph showing the relationship between the thickness of the resist film remaining after the development process and the radiation dose of the KrF excimer laser.

[0030] Description of Reference Numerals

[0031] 1…semiconductor wafer; 3…underlayer film; 3A…patterned underlayer film; 3a, 5a…grooves; 5…resist film; 5A…resist pattern; 5E…portion of the resist film irradiated with extreme ultraviolet rays; 7…mask; R1…extreme ultraviolet rays; R2…ultraviolet rays; 11, 12, 13, 14…processing module; 20…substrate processing device; 24…carrier block; 25…processing block; 26…interface block; 30…exposure device; 40…exposure unit; 41…housing; 42…transport port; 50…moving mechanism; 51…supporting portion; 52…supporting table; 53…rotating portion; 54…loading table; 60…light source module; 61…housing; 62…light source; 63…shuttle; 64…moving mechanism for shutter; 100…control device; C…carrier; W…workpiece; U1, U2…processing unit. DETAILED DESCRIPTION

[0032] Hereinafter, the embodiments of the present invention are illustrated for explaining the present invention. However, the present invention should not be limited to the following contents. In the following description, the same reference numerals are used for the same elements or elements having the same functions, and repeated descriptions are sometimes omitted.

[0033] Figure 1 is a flowchart showing an example of a method for forming a resist pattern (a method for forming a resist pattern). Figure 2 , Figure 3 and Figure 4 The present invention is a process diagram showing an example of a method for forming a resist pattern and a method for manufacturing a semiconductor device including forming a resist pattern using the method.

[0034] form Figure 1 to Figure 4The method for forming a resist pattern shown in the figure includes, in order: a step S10 of applying a photoresist composition on a lower film 3 (film to be etched) provided on a semiconductor wafer 1; a step S11 of forming a resist film 5 by baking the applied photoresist composition; a step S20 of pattern exposure of irradiating a portion (5E) of the resist film 5 with extreme ultraviolet rays R1; a step S30 of post-exposure baking of baking the resist film 5 after pattern exposure; a step S40 of irradiating the entire region of the resist film 5 including the portion 5E irradiated with extreme ultraviolet rays R1 and the portion other than the portion 5E with ultraviolet rays R2; and a step S50 of developing a resist pattern 5A having a groove 5a exposing the lower film 3 by removing a portion of the resist film 5 by development. Extreme ultraviolet rays R1 are radiation having a wavelength of less than 100 nm, referred to as EUV. The wavelength of EUV may be, for example, 13.5 nm. Ultraviolet rays R2 are radiation having a wavelength of more than 100 nm. The step S30 of post-exposure baking may also be omitted.

[0035] The resist film 5 includes a resist material. The photoresist composition used to form the resist film 5 includes a resist material and a solvent. The resist material may be a metal oxide photoresist material.

[0036] The metal oxide photoresist material may, for example, include an organic metal compound, which includes a metal oxide containing a metal atom and an organic ligand bonded to the metal atom. The metal oxide photoresist material may not include an acid generator. The metal oxide photoresist material may also be a nanoparticle (a particle with a maximum width of less than 1 μm). The metal oxide may be a cage compound. It is believed that the metal oxide photoresist material containing an organic metal compound forms a cross-linked structure through the following reaction, the reaction comprising: the organic ligand (organic ligand) is separated from the metal atom by irradiation with extreme ultraviolet light R1; and the metal atoms after the organic ligand is separated are bonded to each other through oxygen atoms and the like through a condensation reaction. Since the formed cross-linked structure is substantially insoluble in the developing material, the metal oxide photoresist material can function as a negative resist material. In the case where the metal oxide photoresist material is a nanoparticle, a plurality of nanoparticles are linked to form a coagulation (cross-linked structure) that is substantially insoluble in the developing material. The formation of the coagulation can be promoted by baking after exposure (step S30). After the agglomerate is formed, by exposing the resist film 45 to ultraviolet light R2 (step S40), the solubility of the portion (unexposed portion) other than the portion 5E irradiated with the extreme ultraviolet light R1 in the resist film 45 changes in the developer material. It is believed that this is because the metal hydroxide is formed from the metal oxide due to the ultraviolet light R2, thereby increasing the hydrophilicity (polarity) of the resist film. Based on the change in the solubility of the resist film caused by the ultraviolet light R2, the dissolution contrast of the resist film during development increases. It is believed that the increase in contrast contributes to the reduction of the roughness of the resist pattern formed.

[0037] By pattern exposure (step S20) using extreme ultraviolet light R1 and, as appropriate, exposure after post-exposure baking (step S30) to fully form a coagulation of the metal oxide photoresist material, the formation of a coagulation (cross-linked structure) can be suppressed in the portion other than the portion 5E irradiated with the extreme ultraviolet light R1, and the detachment of the organic ligand and the formation of the metal hydroxide are promoted. This can contribute to the improvement of the contrast of the development. When ultraviolet light is irradiated before pattern exposure (step S20) based on extreme ultraviolet light R1, a coagulation is also formed in the portion other than the portion 5E irradiated by the extreme ultraviolet light R1, so the contrast may be reduced. By the simultaneous exposure of ultraviolet light (step S40), the organic ligand remaining (residual) in the coagulation can be detached in the portion 5E irradiated with the extreme ultraviolet light R1. When the organic ligand detaches, the resist film becomes hydrophilic, so that the solubility in the organic solvent is reduced. As a result, the sensitivity can be further improved.

[0038] The metal oxide of the metal oxide photoresist material may contain, for example, at least one metal atom selected from Sn, Sb, In, Ti, Zr, Hf, V, Co, Mo, W, Al, Ga, Si, Ge, P, As, Y, La, Ce and Lu. The organic ligand bonded to the metal atom of the metal oxide may be, for example, a branched or unbranched alkyl group that may have a substituent, or may be a cycloalkyl group that has a substituent. Alkyl and cycloalkyl groups can be bonded to metal atoms at primary, secondary or tertiary carbon atoms. The number of carbon atoms of the alkyl and cycloalkyl groups may be 1 to 30. Examples of alkyl groups as organic ligands include methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl and n-octyl. Examples of cycloalkyl groups as organic ligands include cyclobutyl, cyclopropyl, cyclohexyl, 1-adamantyl and 2-adamantyl. Examples of substituents that alkyl and cycloalkyl groups can have include cyano, alkylthio, silyl, alkoxy, alkylcarbonyl, alkylcarbonyl and halo. Nanoparticles containing caged tin oxide and organic ligands can be, for example, of the formula: [(SnR) 12 O 14 A compound represented by [(OH)6](OH)2 (R represents an organic ligand).

[0039] The solvent constituting the photoresist composition for forming the resist film 5 is selected from solvents capable of dispersing or dissolving the resist material. Examples of the solvent are ketones such as cyclohexanone and methyl-2-pentyl ketone; alcohols such as 3-methoxybutanol, 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol, and 1-ethoxy-2-propanol; ethers such as propylene glycol monomethyl ether, ethylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monoethyl ether, propylene glycol dimethyl ether, and diethylene glycol dimethyl ether; and esters such as propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, ethyl lactate, ethyl pyruvate, butyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, including tert-butyl acetate, tert-butyl propionate, propylene glycol monomethyl ether acetate, and propylene glycol monotert-butyl ether acetate.

[0040] The amount of the solvent in the photoresist composition is adjusted within a range that allows the resist film 5 to be appropriately formed by spin coating, etc. For example, the amount of the solvent may be 500 to 100,000 parts by mass based on 100 parts by mass of the metal oxide photoresist material.

[0041] The photoresist composition is applied on the lower film 3, for example, by spin coating (step S10). The applied photoresist composition is baked to remove the solvent in the photoresist composition (step S11). A preformed resist film 5 may also be laminated on the lower film 3. The thickness of the resist film 5 may be, for example, 1 to 5000 nm, 10 to 1000 nm, or 30 to 200 nm.

[0042] The resist film 5 may also be formed by a vapor deposition method instead of a method based on coating and baking of a photoresist composition. Examples of applicable vapor deposition methods include physical vapor deposition (PVD), chemical vapor deposition (CVD) and atomic layer deposition (ALD). The resist film 5 may also be formed by a vapor deposition method, which includes supplying a reaction gas to the gas phase of the exposed lower film 3, the reaction gas containing a precursor of an organic metal compound constituting a metal oxide photoresist material and a co-precursor (e.g., water) that reacts with the precursor to generate the organic metal compound. The organic metal compound generated by the reaction of the precursor with the co-precursor in the gas phase may be deposited on the lower film 3, or the organic metal compound may be generated by the reaction of the precursor deposited on the lower film 3 with the co-precursor.

[0043] The lower film 3 can be a film containing a silicon-containing material, wherein the silicon-containing material contains silicon atoms and carbon atoms bonded to the silicon atoms. The lower film 3 containing the silicon-containing material can be, for example, a film formed by heating a film containing a composition of polycarbosilane having an organic group bonded to the silicon atom or polysiloxane having an organic group bonded to the silicon atom. The lower film 3 containing the silicon-containing material easily absorbs ultraviolet rays R2. Therefore, by irradiation with ultraviolet rays R2, the region (lower region) near the lower film 3 in the resist film 5 is particularly promoted to detach from the organic ligand, and the region can be hydrophilized. When the region near the lower film 3 of the resist film 5 is hydrophilized, especially when the developing material is an organic material, the solubility of the portion 5E irradiated by the extreme ultraviolet rays R1 in the developing material is reduced, so that the wall surface of the resist pattern will not be greatly tilted relative to the lower film 3, and it is easy to form a resist pattern having a wall surface in a direction that is at right angles or close to right angles to the thickness direction of the lower film 3. It should be noted that, compared with irradiating the ultraviolet rays R2 before forming the resist film 5, it is believed that when the ultraviolet rays R2 are irradiated after the resist film 5 is formed, the organic ligands in the lower region of the resist film 5 are easily detached, that is, the hydrophilization is easily performed. As a reason for this, it is believed that when the ultraviolet rays R2 are irradiated before the resist film 5 is formed, the effect of the lower film promoting the detachment of the organic ligands in the lower region of the resist film 5 is relatively weakened as time passes until the resist film 5 is formed. When the ultraviolet rays R2 are irradiated after the resist film 5 is formed, the ultraviolet rays R2 reach the lower film 3 because the wavelength of the ultraviolet rays R2 is sufficiently longer than the wavelength of EUV.

[0044] The formed resist film 5 is irradiated with extreme ultraviolet rays R1 through a mask 7 having an opening disposed on the resist film 5 (step S20). Thus, the portion (5E) of the resist film 5 exposed in the opening of the mask 7 is irradiated with extreme ultraviolet rays R1 having a pattern corresponding to the opening. Instead of using a mask, extreme ultraviolet rays R1 may be irradiated along a predetermined pattern.

[0045] After the irradiation of the extreme ultraviolet light R1, the mask 7 is removed and the resist film 5 is baked (step S30). The heating for baking after the pattern exposure using the extreme ultraviolet light R1 can be performed in the atmosphere, in an inert gas atmosphere such as nitrogen and argon, or in a humidified environment. The pressure of the atmosphere for baking after exposure can be atmospheric pressure or a pressure lower than atmospheric pressure. The heating temperature can be 50°C to 250°C or 170°C to 250°C, and the heating time can be 10 seconds to 300 seconds or 50 seconds to 300 seconds. When the heating temperature for baking after exposure is high, the contrast of the development can be further improved when the developing material is an alkaline aqueous solution or water. The baking after exposure can be a one-step heating at a certain temperature, or it can include two or more steps of heating at different temperatures. For example, the baking after exposure can include a first step of heating at a temperature of 80°C to 170°C, and a second step of heating at a temperature of 180°C to 250°C. In order to promote the formation of metal hydroxide by hydrolysis reaction, the first step can be performed in the atmosphere and in a humidified environment. The second step can be performed under atmospheric pressure, under a reduced pressure atmosphere, or under an inert gas environment.

[0046] Next, the entire region including the portion 5E irradiated by the extreme ultraviolet light R1 and the other portions in the resist film 5 is irradiated with ultraviolet light R2 (step S40, exposure together). When the ultraviolet light R2 is irradiated, the solubility of the portion 5E irradiated by the extreme ultraviolet light R1 with respect to the developing material selectively changes. In this specification, exposure together includes not only the case where the entire region including the portion 5E irradiated by the extreme ultraviolet light R1 and the other portions in the resist film 5 is simultaneously exposed to ultraviolet light, but also includes the case where a portion of the region is exposed while the exposed region is moved so that the entire region is exposed.

[0047] Ultraviolet ray R2 can be ultraviolet ray with a wavelength of more than 100nm and less than 450nm, or more than 100nm and less than 300nm. The wavelength of ultraviolet ray R2 can also be more than 170nm, more than 200nm or more than 250nm. Ultraviolet ray with a wavelength of more than 170nm is suitable for exposure in the atmosphere. Ultraviolet ray with a wavelength of more than 200nm can inhibit side reactions such as oxidation reactions. Ultraviolet ray R2 can also be ultraviolet ray with a wavelength of 254nm, 270nm, 280nm, 365nm, 385nm or 395nm, or it can be ultraviolet ray with a wavelength of 254nm, 270nm or 280nm. The light source of ultraviolet ray R2 can be, for example, a mercury lamp, a xenon lamp, an LED or a laser light source. They can be easily mounted on the exposure unit described later. LED is particularly excellent in the control of high-precision exposure and long-term exposure stability, and is therefore suitable for controlling the size of the resist pattern with high precision. The dose of ultraviolet light R2 (for example, LED-based ultraviolet light) can be, for example, 0.005 to 100 J / cm 2 , 0.005~90J / cm 2 , 0.005~80J / cm 2 , 0.005~70J / cm 2 , 0.005~60J / cm 2 , 0.005~50J / cm 2 , 0.005~40J / cm 2 , 0.005~30J / cm 2 or 0.005~20J / cm 2 The dose of UV R2 can also be 1J / cm 2 Above, 2J / cm 2 Above, 3J / cm 2 Above, 4J / cm 2 Above or 5J / cm 2 The exposure using the ultraviolet rays R2 can be performed by immersion photolithography or dry photolithography.

[0048] Next, a portion of the resist film 5 is removed by development, thereby forming a resist pattern 5A having a groove 5a exposing the underlying film 3 (step S50, Figure 4 (f)). The portion 5E irradiated with the extreme ultraviolet light R1 is substantially insoluble in the developing material and remains as the resist pattern 5A.

[0049] The development may be wet development including a method of bringing the resist film 5 into contact with a developer, or dry development including a method of exposing the resist film 5 to a developing gas.

[0050] The developer used for wet development is selected from developers that effectively dissolve the portion other than the portion 5E irradiated with the extreme ultraviolet rays R1. The developer material may be, for example, an organic developer, an alkaline aqueous solution, or water.

[0051] Examples of organic developers include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, amyl acetate, isoamyl acetate, methoxyethyl acetate, ethoxyethyl acetate, 2-heptanone, propylene glycol monomethyl ether acetate, isopropyl alcohol, ethylene glycol monoethyl ether acetate, ethylene glycol monopropyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monophenyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monopropyl ether acetate, diethylene glycol monoethyl ether acetate, Acid esters, diethylene glycol monophenyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, 2-methoxybutyl acetate, 3-methoxybutyl acetate, 4-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-ethyl-3-methoxybutyl acetate, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, 2-ethoxybutyl acetate, 4-ethoxybutyl acetate, 4-propoxybutyl acetate, 2-methoxypentyl acetate, 3-methoxypentyl acetate, 4-methoxypentyl acetate, 2-methyl-3-methoxypentyl acetate, 3-methyl-3-methoxypentyl acetate, 3-methyl-4-methoxypentyl acetate, 4-methyl-4-methoxypentyl acetate, propylene glycol diacetate, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate, lactate The organic developer may be a mixture of butyl acetate, 2-heptanone, propylene glycol monomethyl ether acetate, or ...

[0052] The alkaline aqueous solution used as a developer can contain, for example, inorganic bases such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and ammonia water, primary amines such as ethylamine and n-propylamine, secondary amines such as diethylamine and di-n-butylamine, tertiary amines such as triethylamine and methyldiethylamine, alcohol amines such as dimethylethanolamine and triethanolamine, quaternary ammonium salts such as tetramethylammonium hydroxide, tetraethylammonium hydroxide, and choline, and alkaline components such as cyclic amines such as pyrrole and piperidine. The alkaline aqueous solution can contain surfactants such as alcohols such as isopropanol and nonionic systems. The developer can be an alkaline aqueous solution containing a quaternary ammonium salt, or tetramethylammonium hydroxide or tetrabutylammonium hydroxide. The rinsing after development using the alkaline aqueous solution can be carried out using water or an organic solvent.

[0053] The developing gas used for dry development may be an acidic gas. The acidic gas may be, for example, a gas containing one or more acid components selected from HBr, acetic acid, and BCl3. The developing gas may also contain a gas formed by gasification of the above-mentioned developer. Dry development may be performed under atmospheric pressure or in an atmosphere with a pressure lower than atmospheric pressure.

[0054] After the development treatment, the end face and the back face of the semiconductor wafer 1 may be cleaned with a cleaning liquid (cleaning liquid). The cleaning liquid may be water, an alkaline aqueous solution or an organic solvent. The organic solvent may also contain an acid component or an alkaline component.

[0055] Figure 5 This is a flowchart showing another example of the method for forming a resist pattern. Figure 5 The method shown includes a temporary development step (step S35) of pre-developing the resist film after post-exposure baking (step S30) and before concurrent exposure using ultraviolet rays (step S40). The temporary development can be a wet development based on contact with a developer, or a dry development. By temporary development, the sensitivity can be further improved. In temporary development, for example, the resist material is particularly effective for metal oxide photoresist materials. It can be that the temporary development is a wet development using a developer, and the development after concurrent exposure is a wet development or dry development using a developer. It is also possible to measure the line width (CD) of the resist pattern after the temporary development, and adjust the dose of the concurrent exposure based on the measured line width.

[0056] Figure 6 This is a flowchart showing another example of the method for forming a resist pattern. Figure 6 The method shown is similar to Figure 1The difference of the method is that after the development step S50, a post-development baking step S60 is included to bake the formed resist pattern. The temperature used for the post-development baking may be higher than the temperature of the post-exposure baking step S30, for example, it may be 230°C to 300°C. The heating time for the post-exposure baking may be 30 seconds to 300 seconds. By post-development baking, the residue in the area other than the part 5E irradiated by the extreme ultraviolet R1 can be effectively removed. In the area other than the part 5E irradiated by the extreme ultraviolet R1 (unexposed part), the detachment of the organic ligand progresses by the irradiation of the ultraviolet R2, thereby the resist material is depolymerized and becomes a state that is easily vaporized by heat, so the residue of the resist material can be effectively removed by the combination of the irradiation of the ultraviolet R2 and the post-exposure baking. It is believed that when the temperature of the post-development baking is higher than the temperature of the post-exposure baking, the residue is easily decomposed and the removal efficiency is further improved.

[0057] The condition of the development step S50 is that the resist film is pre-developed, and the development can be completed by the post-development baking step S60. In this case, in the development step S50, the pattern of the resist is not completely resolved (developed), so it is particularly difficult to cause deformation and collapse (collapse) of the pattern. Furthermore, since no liquid is used in the post-development baking step S60, the deformation and collapse of the pattern caused by the surface tension of the liquid can be avoided, and the pattern shape can be adjusted. An example of the adjustment of the pattern shape includes: in the development step S50, a step of forming a resist pattern having a size larger than the target size and / or a surface rougher than the target roughness; and in the post-development baking step S60, a step of reducing the size of the resist pattern and / or the roughness of the surface of the resist pattern to form a resist pattern having a size and roughness closer to the target size and roughness.

[0058] In the method of forming a resist pattern, the resist pattern formed by development may be further exposed to ultraviolet light. The light source of ultraviolet light used for exposure after development may be an LED or a UV lamp that emits light having a peak between 160 nm and 420 nm.

[0059] The method for manufacturing a semiconductor device further comprises the following steps: Figure 4 As shown in (g) and (h) of FIG. 5 , the lower film 3 exposed in the groove 5a of the resist pattern 5A is etched, thereby forming a lower film 3A patterned in a manner to form the groove 3a. The method for etching the lower film 3 can be selected in consideration of the type of material constituting the lower film 3, for example, dry etching or wet etching. After etching, the resist pattern 5A can be removed. By Figure 4 The illustrated method can obtain a processed substrate 10 having a semiconductor wafer 1 and a patterned lower layer film 3A.

[0060] The patterned lower film 3A may be, for example, an active layer, a lower insulating film, a gate electrode film, or an upper insulating film. Wiring may also be embedded in the groove 3a of the lower film 3A. According to the method of the present invention, for example, a semiconductor device including a semiconductor substrate and an integrated circuit including a patterned lower film formed on the semiconductor substrate can be manufactured.

[0061] By using the resist pattern formed by the method of the present invention as a mask for etching, a mask for photolithography or a template for nanoimprinting can also be manufactured. The mask for photolithography may be a transmission mask or a reflection mask.

[0062] In order to implement the method exemplified above, for example, a substrate processing device can be used, which mainly includes: a heat treatment unit, which bakes the resist film formed on the workpiece having the lower film; an exposure unit, which irradiates ultraviolet light to the resist film having a portion irradiated with extreme ultraviolet light; a developing unit, which removes a portion of the resist film by development, thereby forming a resist pattern; and a control unit, which controls the exposure unit so that ultraviolet light is irradiated to the entire area of ​​the resist film including the portion irradiated with the extreme ultraviolet light and the portion other than the portion.

[0063] Figure 7 and Figure 8 It is a schematic diagram showing an example of a substrate processing apparatus. Figure 7 An example of an exposure device used in combination with a substrate processing device is also shown. Figure 8 express Figure 7 An example of the internal structure of the substrate processing apparatus 20 is shown. Figure 7 and Figure 8 The substrate processing apparatus 20 shown includes a carrier block 24, a processing block 25, and an interface block 26. The substrate processing apparatus 20 is used to process the workpiece W according to the above method.

[0064] The carrier block 24 is a block configured to introduce the workpiece W into the substrate processing device 20 and take the workpiece W out of the substrate processing device 20. The carrier block 24 has a conveying device A1 including a transfer arm. The conveying device A1 takes out the workpiece W stored in the carrier C and hands it to the processing block 25, receives the workpiece W from the processing block 25 and returns it to the carrier C.

[0065] The processing block 25 includes processing modules 11, 12, 13, and 14, which are stacked in this order. The processing modules 11, 12, 13, and 14 respectively have a plurality of processing units U1, U2 and a conveying device A3 for conveying the workpieces W to these processing units.

[0066] The processing module 11 may also be configured to form a lower film (etched film) on the surface of a substrate (e.g., a semiconductor wafer) as a workpiece W. In the processing module 11, for example, the processing unit U1 may be a liquid processing unit that applies a coating liquid for forming the lower film to the workpiece W, and the processing unit U2 may be a heat treatment unit that performs a heat treatment on the applied coating liquid to form the lower film.

[0067] The processing module 12 may also be configured to form a resist film on the lower film (etched film) of the workpiece W. In the processing module 12, for example, the processing unit U1 may be a coating unit for coating the photoresist composition on the workpiece W, and the processing unit U2 may be a heat treatment unit for baking the coated photoresist composition to form a resist film. The workpiece W having the resist film may also be transported to the exposure device 30 via the interface block 26, where a portion of the resist film is irradiated with extreme ultraviolet rays.

[0068] The processing module 13 may also be configured to bake the resist film having the portion irradiated with the extreme ultraviolet light in the exposure device 30, and then irradiate the entire resist film with ultraviolet light. In the processing module 13, for example, the processing unit U1 may be a heat treatment unit for baking the resist film before irradiation with ultraviolet light, and the processing unit U2 may be an exposure unit having an ultraviolet light source.

[0069] The exposure unit for irradiating the resist film with ultraviolet rays may include an ultraviolet light source module fixed inside the exposure unit. In this case, the ultraviolet rays may be irradiated by passing the workpiece W through an exposure area exposed to ultraviolet rays from the light source module. The exposure unit may also include a mechanism for rotating the workpiece W while the workpiece W passes through the exposure area. By irradiating the ultraviolet rays while rotating the workpiece W, the deviation of the irradiated dose can be suppressed.

[0070] Fig. 9 It is a schematic diagram which shows an example of an exposure unit. Fig. 9 The exposure unit 40 shown has a rectangular housing 41, and a moving mechanism 50, a support 51, and a light source module 60 provided inside the housing 41. A transport port 42 is provided on the side wall of the housing 41, and the transport port 42 is an opening for taking out and putting in the workpiece W. The moving mechanism 50 is provided on the bottom surface inside the housing 41, and the support 51 is mounted on the moving mechanism 50. The support 51 has a support table 52 fixed to the moving mechanism 50; a rotating portion 53 extending vertically upward from the supporting table 52; and a disc-shaped mounting table 54 mounted on the upper end of the rotating portion 53. The workpiece W introduced from the transport port 42 is mounted on the mounting table 54. The mounting table 54 attracts and holds the workpiece W. The housing 41 is usually arranged in an orientation in which the bottom surface on which the moving mechanism 50 is provided becomes horizontal, and the workpiece W is held on the mounting table 54 in a manner in which its main surface becomes horizontal.

[0071] The light source module 60 is provided above the moving mechanism portion 50 and the support portion 51 inside the housing 41. The light source module 60 includes a housing 61 and a light source 62 provided inside the housing 61. The housing 61 includes an opening 61a formed just below the light source 62, and is further provided with a shutter 63 for opening and closing the opening 61a. The shutter 63 moves between a closed position for closing the opening 61a and an open position for opening the opening 61a by a shutter moving mechanism portion 64 provided inside the housing 61.

[0072] When the light source 62 is turned on and the shutter 63 is moved to the open position to open the opening 61a, the support portion 51 is moved horizontally inside the housing 41 by the moving mechanism portion 50, thereby irradiating the entire resist film of the workpiece W with ultraviolet rays. During this period, the workpiece W rotates around its central axis due to the rotation of the rotating portion 53.

[0073] The processing module 14 may also be configured to function as a developing unit that removes a portion of the resist film irradiated with ultraviolet rays by contacting with a developing material, thereby forming a resist pattern. In the processing module 14, for example, the processing unit U1 may be a liquid processing unit that supplies a developing material to the resist film and supplies a rinse liquid as needed, and the processing unit U2 may be a heat treatment unit for heat treatment of the resist film before development. The simultaneous exposure of ultraviolet rays by the exposure unit, the baking by the heat treatment unit, and the development by the liquid processing unit are performed online and continuously, which is advantageous in shortening the processing time and suppressing the influence of the dimensional variation of the resist film in the step.

[0074] The processing block 25 also has a shelf unit U10 disposed on the side of the carrier block 24. The shelf unit U10 is divided into a plurality of unit chambers arranged in the vertical direction. A conveying device A7 including a lifting arm is disposed near the shelf unit U10. The conveying device A7 lifts and lowers the workpiece W between the unit chambers of the shelf unit U10. The processing block 25 has a shelf unit U11 disposed on the side of the interface block 26. The shelf unit U11 is divided into a plurality of unit chambers arranged in the vertical direction.

[0075] The interface block 26 is configured to be able to deliver the workpiece W between the processing block 25 and the exposure device 30. The interface block 26 is built with a conveying device A8 (conveying unit) including a delivery arm. The conveying device A8 delivers the workpiece W arranged on the shelf unit U11 to the exposure device 30. The conveying device A8 receives the workpiece W from the exposure device 30 and returns it to the shelf unit U11.

[0076] The control device 100 (control unit) controls the units constituting each block to form a target resist pattern on the workpiece W. For example, the control device 100 controls the exposure unit (e.g., the processing unit U1 in the processing module) to irradiate the entire area of ​​the resist film including the portion irradiated with the extreme ultraviolet rays and the portion other than the portion irradiated with the extreme ultraviolet rays. In addition, the control device 100 can also control the transport unit (transport device A8) of the interface block 26 to transport the workpiece having the resist film irradiated with the extreme ultraviolet rays in the exposure device 30 to the exposure unit.

[0077] The control device 100 may also include a memory storing a program for causing the units constituting each block to execute the above method. The memory includes, for example, a computer-readable storage medium storing the program and a device for reading data from the storage medium. The storage medium is a non-temporary medium, and examples thereof include a hard disk and a read-only memory (ROM).

[0078] The specific structure of the substrate processing apparatus is not limited to the structure of the substrate processing apparatus 20 illustrated above. For example, an exposure unit may be provided between the processing block and the interface block to irradiate ultraviolet rays to the resist film having the portion irradiated with the extreme ultraviolet rays.

[0079] [Example]

[0080] The present invention is not limited to the following verification examples.

[0081] 1. Photoresist composition

[0082] As a resist material, nanoparticles ([(SnR) 12 O 14 ((OH)6](OH)2, R is an alkyl group, hereinafter sometimes referred to as "MOR"). A MOR solution with a concentration of 0.01 M was prepared as a photoresist composition.

[0083] 2. Resist lower layer film

[0084] A coating liquid for forming an underlayer film containing polycarbosilane containing a structural unit having a silicon atom and a hydrocarbon group bonded to the silicon atom is applied to the entire surface of a silicon wafer, and the coating film is heated to form an underlayer film containing a silicon-containing material containing silicon atoms and carbon atoms.

[0085] 3. Inspection test

[0086] Test 1

[0087] The photoresist composition was applied to the lower film formed on the silicon wafer using a spin coater. The coating was heated at 100°C for 60 seconds to remove the solvent, forming a resist film with a thickness of about 15 nm. The resist film was exposed to extreme ultraviolet light (EUV) with a wavelength of 13.5 nm. The exposure amount was increased from 0 mJ / cm 2 (No exposure) changes to 46mJ / cm 2 , while exposing multiple areas, thereby preparing multiple resist films containing areas with different EUV irradiation doses. The exposed resist film was baked at 180°C by heating for 60 seconds. The entire surface of the baked resist film was exposed at once using a KrF excimer laser (wavelength: 248nm). The dose was 0mJ / cm 2 (no exposure), 10mJ / m 2 、20mJ / m 2 or 30mJ / m 2 The resist films exposed collectively by the KrF excimer laser were developed using a developer containing propylene glycol monomethyl ether acetate and acetic acid (PGMEA / AA). The thickness of the resist film remaining after the development process was measured.

[0088] Fig.10 This is a graph showing the relationship between the thickness of the resist film remaining after the development process and the EUV dose. By ultraviolet exposure after EUV exposure, it was confirmed that the thickness of the resist film remaining tends to change with a higher contrast relative to the EUV radiation dose.

[0089] Test 2

[0090] The photoresist composition was applied to the lower film formed on the silicon wafer using a spin coater. The coating was heated at 100°C for 60 seconds to remove the solvent, forming a resist film with a thickness of about 15 nm. The resist film was exposed using a KrF excimer laser. The dose was increased from 0 J / cm 2 (No exposure) changes to 46J / cm 2 , while exposing multiple areas, thereby preparing multiple resist films containing areas with different EUV irradiation doses. The exposed resist film was baked at 180°C by heating for 60 seconds. The entire surface of the baked resist film was exposed at once using a KrF excimer laser (wavelength: 248nm). The dose was 0mJ / cm 2 (no exposure) or 10mJ / cm 2In the method of , a plurality of resist films were exposed collectively by KrF excimer laser. The resist films collectively exposed by KrF excimer laser were developed by tetramethylammonium hydroxide aqueous solution (TMAH). The thickness of the resist film remaining after the development process was measured.

[0091] Fig.11 It is a graph showing the relationship between the thickness of the resist film remaining after the development process and the dose of the first KrF excimer laser. It was confirmed that the thickness of the resist film changes with high contrast relative to the dose by exposing the ultraviolet light after the exposure using the KrF excimer laser. It was also confirmed that the amount of the residue in the area with a small dose of the KrF excimer laser is further reduced compared with the case of using PGEMA / AA as a developer. It is believed that the case of pattern exposure based on EUV also has a tendency to improve the contrast relative to the dose.

[0092] Test 3

[0093] The photoresist composition was applied to the lower film formed on the silicon wafer using a spin coater. The coating was heated at 100°C for 60 seconds to remove the solvent, forming a resist film with a thickness of about 15 nm. The resist film was exposed using EUV. The dose was increased from 0 J / cm 2 (No exposure) changes to 46J / cm 2 , while exposing multiple areas, thereby preparing multiple resist films containing areas with different EUV irradiation doses. The exposed resist film was baked at 200°C by heating for 60 seconds. The entire surface of the baked resist film was exposed at once using a KrF excimer laser (wavelength: 248nm) or a Xe excimer laser (wavelength: 172nm). The resist film exposed at once using a KrF excimer laser or a Xe excimer laser was developed using an aqueous solution of tetramethylammonium hydroxide (TMAH). The thickness of the resist film remaining after the development process was measured using a thickness measurement system (KLATencor Aleris).

[0094] Fig.12 This is a graph showing the relationship between the thickness of the resist film remaining after the development process and the EUV dose. For comparison, Fig.12 The results are also shown in the case where no simultaneous exposure using KrF excimer laser was performed in Experiment 1. By simultaneous exposure to ultraviolet light after EUV exposure, when the wavelength of ultraviolet light was 172 nm, it was also confirmed that the thickness of the remaining resist film tended to change with high contrast relative to the EUV radiation dose.

[0095] Test 4

[0096] A photoresist composition was applied to the lower film formed on the silicon wafer using a spin coater. The coating was heated at 160°C for 60 seconds to remove the solvent and form a resist film with a thickness of 22 nm. The resist film was exposed using EUV through a mask having a pattern corresponding to a line / space with a half pitch of 16 nm. A plurality of resist films with different EUV irradiation doses were prepared. After exposure, the resist film was baked by heating at 200°C for 60 seconds. The entire surface of the baked resist film was exposed at once using a KrF excimer laser. The dose of the KrF excimer laser is 70 mJ / cm 2 The resist film exposed collectively by the KrF excimer laser was developed by TMAH.

[0097] The resist film after EUV exposure similar to the above was baked by heating at 180° C. for 60 seconds without exposing it with KrF excimer laser. The baked resist film was developed by TMAH.

[0098] After the development process, the formed linear resist pattern was observed with a scanning electron microscope to measure the line width (CD), line width roughness (LWR), and number of defects (number of portions where the resist film was missing) of the resist pattern. Fig.13 This is a graph showing the relationship between CD and EUV dose. Fig.14 is a graph showing the relationship between LWR and CD. Fig.15 It is a graph showing the relationship between the number of defects (defect quantity) and CD. From these results, it was confirmed that the margin of EUV exposure related to CD, LWR and the number of defects was improved by ultraviolet exposure after EUV exposure.

[0099] Test 5

[0100] A photoresist composition was applied to the lower film formed on the silicon wafer using a spin coater. The coating was heated at 100°C for 60 seconds to remove the solvent and form a resist film with a thickness of 22 nm. The resist film was exposed using EUV through a mask having a pattern corresponding to a plurality of columns arranged at intervals of 36 nm. A plurality of resist films with different EUV doses were prepared. After exposure, the resist film was baked by heating at 160°C for 60 seconds. The entire surface of the baked resist film was exposed at once using a KrF excimer laser. The dose of the KrF excimer laser was 50 mJ / cm 2 The resist film exposed collectively by the KrF excimer laser was developed using deionized water (DIW).

[0101] The resist film after EUV exposure similar to the above was baked by heating at 160° C. for 60 seconds without exposing it all at once with KrF excimer laser. The baked resist film was developed with deionized water.

[0102] After the development process, the formed linear resist pattern was observed with a scanning electron microscope, and the width (CD) of the formed pillars was measured. Fig.16 It is a graph showing the relationship between CD and EUV dose. It was confirmed that even when the developer was deionized water, a pattern could be formed by development while maintaining a high margin of EUV exposure.

[0103] Test 6

[0104] The photoresist composition was applied to the lower film formed on the silicon wafer using a spin coater. The coating was heated at 100°C for 60 seconds to remove the solvent and form a resist film with a thickness of 22 nm. The resist film was exposed using a KrF excimer laser. The dose was changed from 0 J / cm 2 (No exposure) changes to 46J / cm 2 , while exposing multiple areas, thereby preparing multiple resist films containing areas with different doses of the irradiated KrF excimer laser. After exposure, the resist film was baked by heating at 210°C for 60 seconds. The entire surface of the baked resist film was exposed to ultraviolet light with a wavelength of 280nm. The resist film exposed together was developed using TMAH. The resist film (resist pattern) after development was baked at 250°C by heating for 60 seconds. The thickness of the resist film (with PDB) remaining after baking was measured. After development, the thickness of the unbaked resist film (w / o PDB) was also measured.

[0105] Fig.17 It is a graph showing the relationship between the thickness of the resist film remaining after the development process and the dose of the KrF excimer laser. It is confirmed that the resist film remaining in the area with a small dose of the pattern exposure using the KrF excimer laser is further reduced by the post-bake after the development process. It is believed that there is also a tendency for the residual resist film to decrease in the case of EUV pattern exposure.

[0106] The present invention includes at least the following aspects. [1]

[0108] A method for forming a resist pattern, comprising:

[0109] a step of irradiating a portion of a resist film including a metal oxide resist material with extreme ultraviolet rays;

[0110] A step of irradiating the entire region of the resist film including the portion irradiated with the extreme ultraviolet light and other portions thereof with ultraviolet light having a wavelength of 100 nm or more; and

[0111] A step of forming a resist pattern by development to remove a portion of the resist film. [2]

[0113] The method according to [1] further comprises:

[0114] A step of baking the resist film after irradiating the extreme ultraviolet rays and before irradiating the ultraviolet rays. [3]

[0116] The method according to [1] or [2], further comprising:

[0117] A step of baking the resist pattern formed by the development. [4]

[0119] The method according to any one of [1] to [3], wherein

[0120] irradiating a portion of the resist film formed on the lower film with the extreme ultraviolet rays,

[0121] The underlayer film is a film containing a silicon-containing material, and the silicon-containing material contains silicon atoms and carbon atoms bonded to the silicon atoms. [5]

[0123] The method according to any one of [1] to [4], wherein

[0124] The development is wet development including contacting the resist film with a developer.

[0125] The developer is a tetramethylammonium hydroxide aqueous solution or water. [6]

[0127] The method according to any one of [1] to [4], wherein

[0128] The development is dry development including exposing the resist film to a developing gas. [7]

[0130] According to the method described in [6],

[0131] The developing gas is an acidic gas. [8]

[0133] A method for manufacturing a semiconductor device having a patterned film, the method comprising:

[0134] A step of forming a resist pattern having an opening for exposing the underlying film on the underlying film by the method described in any one of [1] to [7]; and

[0135] The step of etching the lower layer film exposed in the opening to pattern the lower layer film. [9]

[0137] A substrate processing device, characterized in that it comprises:

[0138] a heat treatment unit capable of baking a resist film formed on a workpiece having an underlying film;

[0139] an exposure unit capable of irradiating the resist film having a portion irradiated with extreme ultraviolet rays with an ultraviolet ray having a wavelength of 100 nm or more;

[0140] a developing unit that forms a resist pattern by developing to remove a portion of the resist film; and

[0141] A control unit controls the exposure unit so as to irradiate the entire region of the resist film including a portion irradiated with the extreme ultraviolet rays and other portions thereof with the ultraviolet rays.

[10]

[0143] A computer-readable storage medium storing a program for causing a device to execute the method described in aspect [1].

Claims

1. A method for forming a resist pattern, characterized in that: Including: a step of irradiating a portion of a resist film including a metal oxide resist material with extreme ultraviolet rays; a step of irradiating the entire region of the resist film including the portion irradiated with the extreme ultraviolet light and other portions thereof with ultraviolet light having a wavelength of 100 nm or more; and A step of forming a resist pattern by development to remove a portion of the resist film.

2. The method according to claim 1, characterized in that Also includes: A step of baking the resist film after irradiating the extreme ultraviolet rays and before irradiating the ultraviolet rays.

3. The method according to claim 2, characterized in that Also includes: A step of baking the resist pattern formed by the development.

4. The method according to claim 1, characterized in that: irradiating a portion of the resist film formed on the lower film with the extreme ultraviolet light, The underlying film is a film including a silicon-containing material including silicon atoms and carbon atoms bonded to the silicon atoms.

5. The method according to claim 1, characterized in that: The development is a wet development including contacting the resist film with a developer, The developer is a tetramethylammonium hydroxide aqueous solution or water.

6. The method according to claim 1, characterized in that: The development is a dry development including exposing the resist film to a developing gas.

7. The method according to claim 6, characterized in that: The developing gas is an acidic gas.

8. A method for manufacturing a semiconductor device having a patterned film, the method comprising: A step of forming a resist pattern having an opening for exposing the underlying film on the underlying film by using the method according to claim 1; and The lower layer film exposed in the opening is etched, thereby patterning the lower layer film.

9. A substrate processing device, characterized in that: include: a heat treatment unit capable of baking a resist film formed on a workpiece having an underlying film; an exposure unit capable of irradiating the resist film having a portion irradiated with extreme ultraviolet rays with an ultraviolet ray having a wavelength of 100 nm or more; a developing unit for forming a resist pattern by developing the resist film to remove a portion of the resist film; and A control unit controls the exposure unit so as to irradiate the entire region of the resist film including a portion irradiated with the extreme ultraviolet rays and other portions thereof with the ultraviolet rays.

10. A storage medium, which is a computer-readable storage medium, characterized in that: A program for causing a device to execute the method according to claim 1 is stored.

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