KR20190068263A - Semiconductor resist composition, and method of forming patterns using the composition - Google Patents

Abstract

The present invention relates to a semiconductor resist composition and a pattern forming method using the same. The semiconductor resist composition comprises nanoparticles containing indium-based quantum dots having a diameter of 1-5 nm and an organic coating material surrounding the quantum dots, a solvent, and a photoacid generator. According to one embodiment, the semiconductor resist composition has increased etch resistance.

Description

TECHNICAL FIELD [0001] The present invention relates to a composition for a semiconductor resist and a pattern forming method using the same. BACKGROUND ART [0002]

The present invention relates to a composition for a semiconductor resist and a pattern forming method using the same.

EUV (extreme ultraviolet light) lithography has been attracting attention as one of the element technologies for manufacturing next-generation semiconductor devices. EUV lithography is a pattern formation technique using EUV light having a wavelength of 13.5 nm as an exposure light source. According to EUV lithography, it is demonstrated that an extremely fine pattern (for example, 20 nm or less) can be formed in an exposure process of a semiconductor device manufacturing process.

  Implementation of extreme ultraviolet (EUV) lithography requires the development of compatible photoresists that can be performed in spatial resolutions of 16 nm or less. At present, traditional chemically amplified photoresists (CA) are used for resolution, photospeed, and feature roughness (also referred to as line edge roughness or LER) for next generation devices, And are working to meet the specifications for.

Intrinsic image blur due to acid catalyzed reactions occurring in these polymeric photoresists limits the resolution at small feature sizes because of e-beam, It has long been known in lithography. Although chemically amplified (CA) photoresists are designed for high sensitivity, their typical elemental makeups lower the absorbance of the photoresists at a wavelength of 13.5 nm and, as a result, reduce the sensitivity, Can be more difficult under EUV exposure.

CA photoresists can also suffer difficulties due to roughness issues at small feature sizes and may be affected by line edge roughness (LER) as the photospeed decreases, partially due to the nature of acid catalyzed processes. In the experiment. Due to the drawbacks and problems of CA photoresists, there is a need in the semiconductor industry for new types of high performance photoresists.

One embodiment provides a composition for a semiconductor resist capable of forming a pattern having a high aspect ratio by increasing etch resistance.

Another embodiment provides a pattern formation method using the composition for semiconductor resists.

According to one embodiment, there is provided a composition for a semiconductor resist comprising nanoparticles and a solvent comprising an indium-based quantum dot having a diameter of 1 nm to 5 nm and an organic coating surrounding the quantum dot.

According to another embodiment, there is provided a method of forming a photoresist pattern, comprising the steps of forming a film to be etched on a substrate, forming a photoresist film by applying the composition for a semiconductor resist according to one embodiment on the film to be etched, And etching the etching target film using the photoresist pattern as an etching mask.

The composition for a semiconductor resist according to one embodiment can provide a photoresist pattern with an increased etch resistance and a fine width of 20 nm or less and a high aspect ratio.

1 to 5 are cross-sectional views for explaining a pattern forming method using a composition for a semiconductor resist according to an embodiment.

Hereinafter, exemplary embodiments of the present invention will be described in detail so that those skilled in the art can easily carry out the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

In the drawings, the thicknesses are enlarged to clearly show the layers and regions, and like parts are denoted by the same reference numerals throughout the specification. Whenever a portion of a layer, film, region, plate, or the like is referred to as being "on" another portion, it includes not only the case where it is "directly on" another portion, but also the case where there is another portion in between. Conversely, when a part is "directly over" another part, it means that there is no other part in the middle.

Unless otherwise defined herein, "substituted" means that the hydrogen atom in the compound is a halogen atom (F, Br, Cl, or I), a hydroxy group, an alkoxy group, a nitro group, a cyano group, an amino group, An ester group, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid or a salt thereof, a vinyl group, a C1 to C20 alkyl group, a C2 to C20 alkene group, a cyano group, C6 to C30 arylalkyl groups, C6 to C30 aryl groups, C1 to C30 alkoxy groups, C1 to C20 heteroalkyl groups, C3 to C20 heteroarylalkyl groups, C3 to C30 cycloalkyl groups , A C3 to C15 cycloalkenyl group, a C6 to C15 cycloalkynyl group, a C3 to C30 heterocycloalkyl group, and combinations thereof.

In addition, unless otherwise defined herein, "hetero" means containing 1 to 3 heteroatoms selected from N, O, S and P.

Also, unless otherwise defined herein, '*' refers to the point of attachment of a compound or moiety.

Hereinafter, a composition for a semiconductor resist according to one embodiment will be described.

Compositions for semiconductor resists in accordance with one embodiment include nanoparticles and solvents comprising an indium based quantum dot having a diameter of 1 nm to 5 nm and an organic coating surrounding the quantum dot.

The nanoparticles have a structure in which the organic coating surrounds the surface of indium-based quantum dots.

Indium-based quantum dots are III-V group nano compounds containing indium, more specifically, but not limited to, InAs, InP, InN, InSb, or combinations thereof. In some cases, two or more nanocrystalline compounds are present in a simple mixed state, or a crystal having a core-shell structure, or a crystal having a gradient structure, A quantum dot formed by a mixed crystal in which at least two kinds of compound crystals are partially separated or an alloy of two or more kinds of nanocrystalline compounds may be used.

Indium-based quantum dots can be prepared by a variety of known techniques, but in general, a precursor containing an indium element and a precursor containing an additional V group element are reacted in solution to form indium and V Group elements are combined to form quantum dots of an indium-V group element.

For example, a first precursor containing an indium element which is a Group III element compound, an organic solvent and a dispersant are added to a reaction vessel to obtain and heat a first mixed solution, a second precursor which is a Group V element compound, And a dispersing agent to obtain a second mixed solution and then heating the mixed solution; adding the second mixed solution to the heated first mixed solution; adding a surfactant in liquid form after the addition of the second mixed solution; And then heating and adding and refining the resultant mixture to synthesize and separate the quantum dots to prepare quantum dots.

The heating may be performed at a temperature of 150 ° C or more and less than 350 ° C, for example, 180 ° C or more and 325 ° C or less, for example, 180 ° C or more and 325 ° C or less.

The diameter of the indium based quantum dot according to one embodiment may be between 1 nm and 5 nm. For example, 1 nm to 4 nm, for example, 1 nm to 3 nm, for example, 1 nm to 2 nm, but is not limited thereto. When the size of the quantum dot is within the above range, the line width roughness (LWR) and the line edge roughness (LER) can be reduced.

The resist composition for a semiconductor according to an embodiment is for forming a pattern using light having a wavelength of less than 15 nm as an exposure light source, such as EUV lithography, and thereby forming an extremely fine pattern of, for example, 20 nm or less , And when the diameter of the quantum dot exceeds 5 nm, it may not be suitable for use in a photoresist composition according to one embodiment for the purpose of implementing a fine pattern.

The indium-based quantum dot may be present in the range of 0 to 10 wt%, for example, 0.5 to 10 wt%, for example, 1 to 7 wt%, for example, 2 to 5 wt% But are not limited thereto.

Indium-based quantum dots within the above-mentioned content range is suitable considering the coating of the photoresist composition and the compatibility with other components except for the quantum dot, and the captor resist which is cured therefrom even if the quantum dots are included in the content range. z can be obtained sufficiently. Therefore, the inclusion of an indium-based quantum dot in an amount exceeding the above-described content range is not preferable from the viewpoint of cost, and is also not preferable from the viewpoint of compatibility with other components other than the quantum dot.

The organic coating may comprise a ligand. The quantum dot may be surrounded by a ligand having a hydrocarbon chain terminal group whose surface is nonpolar by the synthesis step or post-treatment to form an organic coating film. Thanks to such a ligand, it is possible to disperse the inorganic quantum dots into a hydrophobic organic solvent, passivate the surface of the quantum dots smoothly, and to store and use the stable.

In one embodiment, the ligand is a substituted or unsubstituted C1-C20 carboxylic acid or salt thereof, a substituted or unsubstituted C1-C20 amino acid or salt thereof, a substituted or unsubstituted C1-C20 dialkylphosphonate, . ≪ / RTI > More specifically, the ligand is a substituted or unsubstituted C1-C20 carboxylic acid or salt thereof containing a functional group containing an ethylenic double bond, a substituted or unsubstituted C1-C20 alkyl group containing a functional group containing an ethylenic double bond An amino acid or salt thereof, a substituted or unsubstituted C1-C20 dialkylphosphonate containing a functional group containing an ethylenic double bond, or a combination thereof.

Specific examples of the ligand include, but are not limited to, palmitic acid, myristric acid, oleic acid, trioctyl phosphine, and the like. In one embodiment, the organic coating comprises one or both of palmitic acid, myristric acid, oleic acid, and trioctyl phosphine, And may include, but is not limited to, two or more of palmitic acid, myristric acid, oleic acid, and trioctyl phosphine.

The solvent may include an amphoteric compound having both a polar group and a non-polar group. In the case of a solvent containing an amphoteric compound, the quantum dot inorganic particles and organic constituents other than the quantum dots, for example, a binder resin, a photopolymerizable monomer, a photopolymerization initiator, a thiol additive, a diffusing agent, . Therefore, in one embodiment, a solvent containing an amphoteric compound can effectively maintain the dispersion stability, pattern processability, and optical characteristics (light conversion rate) of the composition for quantum dot-containing semiconductor resist.

The polar group contained in the amphoteric compound is represented by -R (C = O) O- wherein R is a substituted or unsubstituted C1 to C20 alkyl group, -C (= O) -, Functional group, and the non-polar group may be a substituted or unsubstituted C1 to C20 alkyl group or a substituted or unsubstituted C3 to C20 cycloalkyl group.

Examples of ampholytic compounds including both polar groups and nonpolar groups such as those described above include pentyl acetate, hexyl acetate, decyl acetate, dodecyl acetate, cyclohexyl acetate, isoamyl acetate, diethyl ether, dibutyl ether, methyl isobutyl Ketones, or combinations thereof.

The amphoteric compound may have a high boiling point. (Boiling point: 148 占 폚), hexyl acetate (boiling point: 169 占 폚), decyl acetate (boiling point: 248 占 폚), dodecyl acetate (boiling point: 150 占 폚), or cyclohexyl acetate (boiling point: 172 占 폚) May have a boiling point of 148 占 폚 to 250 占 폚, such as 148 占 폚 to 180 占 폚. At this time, the solvent may further contain a compound having a boiling point lower than that of the amphoteric compound, for example, propylene glycol monomethyl ether acetate (boiling point: 145 占 폚).

The composition for a semiconductor resist according to an embodiment may further include a resin.

The resin may be a phenolic resin containing at least one aromatic moiety listed in Group 1 below.

[Group 1]

The resin may have a weight average molecular weight of 500 to 20,000.

The resin may be contained in an amount of 0.1% by weight to 50% by weight based on the total amount of the composition for semiconductor resist.

When the resin is contained in the above content range, it can have excellent corrosion resistance and heat resistance.

Meanwhile, the composition for a semiconductor resist according to an embodiment may further include a photoacid generator (PAG) in addition to the resin.

The photoacid generator is a substance that is decomposed by light to generate an acid, and is a substance used for chemical amplification to improve photosensitivity of the photoresist. The photoacid generator may include at least one of, for example, a diazosulfone compound or a triphenylsulfone compound, but is not limited thereto.

The photoacid generator may specifically be represented by the following formula (1) or (2).

[Chemical Formula 1]

(2)

In the above formulas (1) and (2)

R ²³ , R ²⁴ and R ²⁶ to R ²⁸ are each independently a hydrogen atom or a substituted or unsubstituted C1 to C40 organic group,

R ²⁵ is a substituted or unsubstituted C 1 to C 20 alkyl group, a substituted or unsubstituted C 2 to C 20 alkenyl group, a substituted or unsubstituted C 3 to C 20 cycloalkyl group, a substituted or unsubstituted C 6 to C 20 aryl group, ,

Z ^- is an anion of an organic acid.

For example, R ²² and R ²³ may be connected to each other to form a ring.

For example, R ²⁶ and R ²⁷ may be connected to each other to form a ring.

For example, Z < ^- > may have a fluorine group (-F).

For example, Z < ^- > may have at least one selected from the group consisting of nitrogen, carbon and sulfonyl groups.

The photoacid generator may be included in an amount of 0.001 wt% to 5 wt%, for example, 0.001 wt% to 3 wt%, for example, 0.001 wt% to 1 wt% based on the total amount of the resist composition. When the photoacid generator is included in the above content range, sensitivity to exposure of the resist may be increased.

As described above, the composition for a semiconductor resist is increased in etch resistance, and pattern collapse may not occur even if a pattern having a high aspect ratio is formed. Thus, for example, a fine pattern having a width of 5 nm to 100 nm, for example, a fine pattern having a width of 5 nm to 80 nm, for example, a fine pattern having a width of 5 nm to 70 nm, For example, a fine pattern having a width of 5 nm to 50 nm, for example, a fine pattern having a width of 5 nm to 40 nm, for example, a fine pattern having a width of 5 nm to 30 nm, In order to form a pattern, a photoresist process using light having a wavelength of 5 nm to 150 nm, for example, a photoresist process using light having a wavelength of 5 nm to 100 nm, for example, a photo using light having a wavelength of 5 nm to 80 nm A resist process, for example, a photoresist process using light of a wavelength of 5 nm to 50 nm, for example, a photoresist process using light of a wavelength of 5 nm to 30 nm, for example, using light of a wavelength of 5 nm to 20 nm artillery It can be used in the resist process. Therefore, by using the composition for a semiconductor resist according to one embodiment, extreme ultraviolet lithography using an EUV light source having a wavelength of about 13.5 nm can be realized.

On the other hand, according to another embodiment, there is provided a photoresist film produced using the above-mentioned composition for a semiconductor resist. The photoresist film may be formed by coating the above-described composition for a semiconductor resist, for example, on a substrate, followed by curing through a heat treatment process.

Hereinafter, a method of forming a pattern using the composition for a semiconductor resist will be described with reference to FIGS. 1 to 5. FIG.

1 to 5 are sectional views for explaining a pattern forming method using the composition for a semiconductor resist according to the present invention.

Referring to FIG. 1, an object to be etched is first prepared. The etching target may be a thin film 102 formed on the semiconductor substrate 100. Hereinafter, only the case where the object to be etched is the thin film 102 will be described. The surface of the thin film 102 is pre-cleaned in order to remove contaminants or the like remaining on the thin film 102. The thin film 102 may be, for example, a silicon nitride film, a polysilicon film, or a silicon oxide film.

Then, a composition for forming a resist lower layer film for forming a resist lower layer film 104 on the surface of the cleaned thin film 102 is coated by applying a spin coating method.

The resist underlayer film coating process may be omitted, and only the case where the resist underlayer film is coated will be described below.

Thereafter, the resist underlayer film 104 is formed on the thin film 102 by performing a drying and baking process. The baking treatment may be carried out at about 100 to about 500, for example at about 100 to about 300.

The resist underlayer film 104 is formed between the substrate 100 and the photoresist film 106 so that the radiation rays reflected from the interface between the substrate 100 and the photoresist film 106 or from the interlayer hardmask are not intended It is possible to prevent the unevenness of the linewidth of the photoresist and the formation of the pattern from being disturbed when scattered into the non-photoresist region.

Referring to FIG. 2, the photoresist film 106 is formed on the resist underlayer film 104 by coating the composition for semiconductor resist described above.

More specifically, the step of forming a pattern using the composition for a semiconductor resist may include a step of applying the composition for semiconductor resist described above onto the substrate 100 by spin coating, slit coating, inkjet printing, or the like, And forming the photoresist film 106 by drying the composition.

Since the composition for a semiconductor resist has already been described in detail, a duplicate description will be omitted.

Next, a first baking process for heating the substrate 100 on which the photoresist film 106 is formed is performed. The first baking process may be performed at a temperature of about 80 to about 120 ° C.

Referring to FIG. 3, the photoresist film 106 is selectively exposed.

Examples of the light that can be used in the exposure process include not only light having a short wavelength such as an activating radiation line i-line (365 nm), a KrF excimer laser (wavelength 248 nm), and an ArF excimer laser (wavelength 193 nm) ultraviolet (wavelength: 13.5 nm), and E-beam (electron beam).

More specifically, the light for exposure according to one embodiment may be short-wavelength light having a wavelength range of 5 nm to 150 nm, or may be a light having a high energy wavelength such as EUV (extreme ultraviolet (wavelength 13.5 nm), E-beam .

As the metal-oxygen bond increases, the photoresist film 106a at the exposed portion has different solubilities with the photoresist film 106b at the non-exposed portion.

Next, a second baking process is performed on the substrate 100. The second baking process may be performed at a temperature of about 90 to about 200. By performing the second baking process, the photoresist film 106a corresponding to the exposed region becomes difficult to dissolve in a specific solvent.

Referring to FIG. 4, a photoresist pattern 106 is formed by dissolving and removing a photoresist film 106b corresponding to the unexposed region using a developing solution. Specifically, the photoresist pattern 106 is completed by dissolving and removing the photoresist film 106b corresponding to the unexposed region using a developing solution such as 2-heptanone.

With the exposure mask pattern having a width of the above-described thickness, the photoresist pattern 108 formed according to an embodiment may also include a pattern having a width of 5 nm to 100 nm in thickness. Thus, the photoresist pattern 108 according to one embodiment may also have a thickness ranging from 5 nm to 90 nm, 5 nm to 80 nm, 5 nm to 70 nm, 5 nm to 60 nm, 10 nm to 50 nm, 10 nm to 40 nm, 10 nm to 30 nm, As shown in FIG.

Then, the resist lower layer film 104 is etched using the photoresist pattern 108 as an etching mask. The organic film pattern 112 is formed by the above-described etching process.

Referring to FIG. 5, the exposed thin film 102 is etched by applying the photoresist pattern 108 as an etching mask. As a result, the thin film is formed into the thin film pattern 114.

The etching may be performed by, for example, dry etching using an etching gas, and the etching gas may be, for example, CHF ₃ , CF ₄ , Cl ₂ , BCl ₃ and a mixed gas thereof.

In the previously performed exposure process, the thin film pattern 114 formed by the exposure process performed using the EUV light source may have a width of 5 nm to 100 nm. For example, the thin film pattern 114 formed by an exposure process performed using an EUV light source may have a thickness ranging from 5 nm to 90 nm, 5 nm to 80 nm, 5 nm to 70 nm, 5 nm to 60 nm, 10 nm to 50 nm, 10 nm to 40 nm, And may have a width of 10 nm to 20 nm, more specifically, a width of 20 nm or less.

Hereinafter, the present invention will be described in more detail by way of examples of synthesis of the polymer and production of a composition for a semiconductor resist containing the same. However, the present invention is not limited by the following examples.

Example

An indium solution was prepared by dissolving 0.0230 g of indium acetate and 0.0703 g of myristric acid in 6 ml of 1-octadecene (ODE). At this time, maintaining the vacuum until 110 ℃, and thereafter was maintained in a nitrogen (N ₂₎ gas atmosphere, 188 ℃. 0.029 ml of tris (trimethylsilyl) phosphine and 0.3 ml of 1-octylamine were rapidly injected into the indium solution to form a solution containing InP nanocrystals.

The synthesized InP nanocrystal solution was washed with a washing solution which is a mixed solvent of acetone, chloroform, butanol, and methanol, and centrifuged to redisperse the collected nanocrystals in CHA (cyclohexyl acetate).

Photo Resist  Film manufacturing

The InP solution synthesized in the Examples was diluted with CHA to prepare a 2 wt% CHA solution, and then filtered through a 0.45 μm PTFE syringe filter to prepare a resist composition. A silicon wafer (10 inches in diameter) having a native-oxide surface was used as a substrate for thin film deposition. The Si substrate was treated with hexamethyldisilazane (HMDS) vapor prime prior to deposition. The resist composition was spin-coated on the substrate at 1500 rpm for 30 seconds and then fired at 100 ° C for 120 seconds on a hot plate to remove residual solvent. The thickness of the film after coating and baking was 21 nm as measured by ellipsometry.

The coated substrate was exposed to an electron beam scanning raster with an HV voltage of 50 keV using JEOL-9300 equipment. The scan line exposure proceeded in a vacuum chamber. The patterned resist and the substrate were fired at 150 ° C for 2 minutes. The exposed film was then immersed in 2-heptanone for 30 seconds to develop and clean to remove portions not exposed to the scan line to form a negative tone image. Finally, a resist film patterned by high-temperature firing at 200 ° C for 5 minutes was obtained. As a result of the measurement with an electron microscope (SEM), the patterned resist film had a resolution of 50 nm line on a 100 nm pitch Respectively.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It is obvious to those who have. Accordingly, it should be understood that such modifications or alterations should not be understood individually from the technical spirit and viewpoint of the present invention, and that modified embodiments fall within the scope of the claims of the present invention.

100: substrate 102: thin film
104: resist lower layer film 106: photoresist film
108: photoresist pattern 112: organic film pattern
114: thin film pattern

Claims (14)

Nanoparticles comprising an indium based quantum dot having a diameter of 1 nm to 5 nm and an organic coating surrounding the quantum dot; And
A composition for a semiconductor resist comprising a solvent. The method of claim 1,
Wherein the organic coating comprises a ligand,
The ligand may be a substituted or unsubstituted C1-C20 carboxylic acid or salt thereof, a substituted or unsubstituted C1-C20 amino acid or salt thereof, a substituted or unsubstituted C1-C20 dialkylphosphonate, or a combination thereof , A composition for semiconductor resists. 3. The method of claim 2,
The ligand may be a substituted or unsubstituted C1-C20 carboxylic acid or a salt thereof, a substituted or unsubstituted C1-C20 amino acid or a salt thereof, a substituted or unsubstituted C1-C20 Dialkyl phosphonate, or a combination thereof. 3. The method of claim 2,
Wherein the ligand comprises a palmitic acid, myristric acid, oleic acid, and trioctyl phosphine, or a combination thereof. The method of claim 1,
Wherein the solvent comprises an amphoteric compound having both a polar group and a nonpolar group. The method of claim 5,
The polar group may be any one of -R (C = O) O-, wherein R is a substituted or unsubstituted C1 to C20 alkyl group, -C (= O) -, Wherein the composition is a composition for semiconductor resist. The method of claim 5,
Wherein the non-polar group is a substituted or unsubstituted C1 to C20 alkyl group or a substituted or unsubstituted C3 to C20 cycloalkyl group. The method of claim 5,
Wherein the amphoteric compound is a combination of pentyl acetate, hexyl acetate, decyl acetate, dodecyl acetate, cyclohexyl acetate, isoamyl acetate, diethyl ether, dibutyl ether or methyl isobutyl ketone, or a combination thereof. The method of claim 1,
Wherein the indium-based quantum dot comprises InAs, InP, InN, InSb, or a combination thereof. The method of claim 1,
Wherein the indium-based quantum dot is contained in an amount of 0 to 5 wt% based on the total weight of the composition for semiconductor resist. The method of claim 1,
Wherein the composition further comprises a resin. 12. The method of claim 11,
Wherein the composition further comprises a photoacid generator. Forming a film to be etched on a substrate;
Forming a photoresist film by applying the composition for a semiconductor resist according to any one of claims 1 to 12 on the film to be etched;
Forming a photoresist pattern by patterning the photoresist film; And
And etching the etching target film using the photoresist pattern as an etching mask. The method of claim 13,
Wherein the step of forming the photoresist pattern uses light having a wavelength of 5 to 150 nm.

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