Use of a composition comprising ammonia and an alkanol to prevent pattern collapse when processing patterned materials with linear spatial dimensions less than 50 nm.

Abstract

The present invention relates to a method for preventing pattern collapse of a substrate having a patterned material layer with a linear spatial dimension of 50 nm or less, an aspect ratio of 4 or more, or a combination thereof, by using a composition consisting essentially of 0.1 to 3% by weight of ammonia and a C1 to C4 alkanol.

Description

[Technical Field]

[0001] The present invention relates to the use of compositions for the manufacture of integrated circuit devices, optical devices, micromachines and precision mechanical devices, particularly to prevent pattern collapse. [Background technology]

[0002] In the manufacturing process of ICs including LSI, VLSI, and ULSI, patterned material layers, such as patterned photoresist layers, patterned barrier material layers including or consisting of titanium nitride, tantalum, or tantalum nitride, patterned multi-stack material layers including or consisting of alternating layers of polysilicon and silicon dioxide or silicon nitride, and patterned dielectric material layers including or consisting of silicon dioxide or low-k or ultra-low-k dielectric materials, are fabricated by photolithography techniques. Nowadays, such patterned material layers comprise structures with high aspect ratios even with dimensions of less than 22 nm.

[0003] However, wet chemical processing of small patterns, regardless of the exposure technique, presents several problems. As technology advances and dimensional requirements become increasingly stringent, patterns are required to include relatively thin and tall structure or device structure features on the substrate, i.e., features with high aspect ratios. These structures can bend and / or collapse, especially during spin-drying, due to excessive capillary forces of the rinse liquid deionized water or solution that remains through the chemical rinsing and spin-drying steps and is disposed between adjacent patterned structures.

[0004] Additionally, as dimensions shrink, particle and plasma etch residue removal becomes a critical factor in achieving defect-free patterned structures, which applies not only to photoresist patterns but also to other patterned material layers encountered in the fabrication of integrated circuits, electronic data storage media, optical devices, micromachines, and precision mechanical instruments.

[0005] WO 2012 / 027667 A2 discloses a method for surface modification of high aspect ratio features by contacting the surface of the high aspect ratio features with an additive composition to produce a modified surface, wherein the force acting on the high aspect ratio features when a rinse liquid contacts the modified surface is sufficiently minimized to prevent bending or collapse of the high aspect ratio features during at least removal of the rinse liquid or at least drying of the high aspect ratio features. Various solvents are listed, including isopropanol, but no esters are listed. Combinations of 4-methyl-2-pentanol and tripropylene glycol methyl ether (TPGME), or isopropanol and TPGME, are also disclosed.

[0006] WO2019 / 086374A discloses a non-aqueous cleaning composition containing a siloxane additive to prevent pattern collapse. Preferably, the solvent is primarily composed of one or more organic solvents, which may be protic or aprotic organic solvents. Preferred are one or more polar protic organic solvents, and most preferred are monopolar protic organic solvents such as isopropanol.

[0007] WO2019 / 224032A discloses a non-aqueous cleaning composition for preventing pattern collapse, which contains a C1-C6 alkanol and a carboxylic acid ester, and is used to treat a substrate having a pattern with a linear spatial dimension of a line width of 50 nm or less and an aspect ratio of 4 or more.

[0008] US 2017 / 17008A discloses a pattern treatment composition comprising a polymer comprising surface attachment groups for forming bonds with the surface of a patterned feature, a solvent, and a second pattern treatment composition different from the first pattern treatment composition. In addition to many other combinations, the solvent can be a combination of n-butyl acetate and isopropanol.

[0009] Unpublished European Patent Application No. 19168153.5 discloses a non-aqueous composition for treating a substrate having a patterned material layer with linear spatial dimensions of 50 nm or less, aspect ratios of 4 or greater, or a combination thereof, comprising an organic protic solvent, ammonia, and a non-ionic H-silane additive.

[0010] However, these compositions suffer from either significant pattern collapse in sub-50 nm, especially sub-22 nm, structures, or leave troublesome residues of non-volatile additives on the surface of the structured substrate being processed. [Prior art documents] [Patent documents]

[0011] [Patent Document 1] WO2012 / 027667A2 [Patent Document 2] WO2019 / 086374A [Patent Document 3] WO2019 / 224032A [Patent Document 4] US2017 / 17008A [Patent Document 5] European Patent Application No. 19168153.5 Summary of the Invention [Problem to be solved by the invention]

[0012] It is an object of the present invention to provide a method for manufacturing integrated circuits for the sub-50 nm node, in particular the sub-32 nm node, especially the sub-22 nm node, which no longer has the drawbacks of prior art manufacturing methods.

[0013] In particular, the compounds according to the present invention enable chemical rinsing of patterned material layers having patterns with high aspect ratios and linear spatial dimensions with line widths of 50 nm or less, particularly 32 nm or less, and especially 22 nm or less, without causing pattern collapse.

[0014] Surprisingly, it has been discovered in unpublished European Patent Application No. 19168153.5 that silane can be removed without significantly impairing pattern collapse rates, and that due to the volatility of its components, it can be completely removed from the substrate surface very easily. In particular, it has been found that even simple two-component compositions consisting primarily of ammonia and a C1-C4 alkanol can achieve low pattern collapse rates. On the other hand, it has been found that several solvent compositions disclosed in WO 2019 / 224032A are less effective at reducing pattern collapse on HARS structures, particularly silicon HARS structures, than the present invention. [Means for solving the problem]

[0015] One embodiment of the present invention comprises: (a) 0.1 to 3 mass% of ammonia, (b) a C1-C4 alkanol; From there he became the Lord, The present invention relates to a method for using the composition to treat a substrate having a patterned material layer with linear spatial dimensions of 50 nm or less, an aspect ratio of 4 or more, or a combination thereof, to prevent pattern collapse.

[0016] Another embodiment of the present invention is The following process: (a) providing a substrate having a patterned material layer with linear spatial dimensions of 50 nm or less, an aspect ratio of 4 or greater, or a combination thereof; (b) contacting the substrate with an aqueous pretreatment composition comprising 0.1 to 2 wt. % HF, preferably 0.25 to 1 wt. % HF; (c) removing the aqueous composition from the substrate; (d) contacting the substrate with an APCC composition consisting essentially of: (i) 0.1 to 3 mass % ammonia, (ii) C1-C4 alkanols, (e) removing the composition from the substrate; The present invention relates to the manufacture of integrated circuit devices, electronic data storage devices, optical devices, micromachines and precision mechanical devices, including:

[0017] The compositions according to the present invention are particularly useful for preventing pattern collapse of non-photoresist patterns having high aspect ratio stacks (HARS). DETAILED DESCRIPTION OF THE INVENTION

[0018] The present invention relates to the use of a composition, particularly for fabricating patterned materials containing features of 50 nm or less in size, such as integrated circuit (IC) devices, data storage devices, optical devices, micromachines, and precision mechanical devices, especially IC devices. This composition is also referred to herein as a "pattern collapse prevention composition" or simply as an "APCC solution," since ammonia is essentially dissolved in a C1-C4 alkanol.

[0019] The process of the present invention can utilize any conventional and well-known substrate used in the manufacture of IC devices, optical devices, micromachines, and precision mechanical devices. Preferably, the substrate is a semiconductor substrate, more preferably a silicon wafer, which is conventionally used in the manufacture of IC devices, particularly IC devices including ICs with LSI, VLSI, and ULSI.

[0020] Here, and in the context of the present invention, the term "patterned material layer" refers to a layer supported on a substrate. The supported layer preferably has a specific pattern with linear spatial structures having a linewidth of 50 nm or less, and the support substrate is typically a semiconductor substrate, e.g., a semiconductor wafer. Such linear spatial structures may be, but are not limited to, pillars and lines. As used herein, "width" refers to the shortest distance from one end of a structure to the other; for example, a 30 nm x 50 nm pillar or a 30 nm x 1000 nm line is 30 nm, and a 40 nm diameter pillar is 40 nm. The term "patterned material layer having linear spatial dimensions of a linewidth of 50 nm or less" means that the patterned material comprises linear spatial structures with a linewidth of 50 nm, but also linear spatial structures smaller (narrower) than 50 nm. The ratio of the linewidth to the width of the space between two adjacent lines is preferably 1:1 or less, more preferably 1:2 or less. It is known to those skilled in the art that patterned material layers having such low "linewidth to spacewidth" ratios require very delicate handling during fabrication.

[0021] The APCC solution is particularly suitable for processing substrates having patterned material layers with linear spatial dimensions of linewidths of 50 nm or less, particularly 32 nm or less, and especially 22 nm or less, i.e., patterned material layers for technology nodes of 22 nm or less. The patterned material layers preferably have aspect ratios of 4 or greater, preferably 5 or greater, more preferably 6 or greater, even more preferably 8 or greater, even more preferably 10 or greater, even more preferably 12 or greater, even more preferably 15 or greater, and even more preferably 20 or greater. The smaller the linear spatial dimensions and the higher the aspect ratio, the more advantageous the use of the compositions described herein. The critical aspect ratio also depends on the substrate being processed to prevent pattern collapse. For example, aspect ratios of 4 or greater are difficult to achieve because low-k dielectrics are more unstable and prone to collapse.

[0022] ammonia The composition contains ammonia in an amount of 0.1 to 3% by weight.

[0023] In a preferred embodiment, the amount of ammonia is 0.2 to 2.8% by weight, in particular 0.3 to 2.7% by weight, more in particular 0.5 to 2.5% by weight, even more in particular 0.8 to 2.2% by weight, and most in particular 1.0 to 2.0% by weight.

[0024] To prepare an APCC composition with a desired ammonia concentration, a fixed stock solution is commercially available. For example, a 4% ammonia solution in IPA (available from TCI) or a 7N solution of ammonia in methanol (available from Acros) can be prepared by bubbling ammonia through the respective solvent until the desired concentration is reached. The ammonia concentration can then be adjusted as desired by adding the appropriate amount of the respective solvent.

[0025] solvent The composition comprises a C1-C4 alkanol (also referred to as "alkanol"). Although it is possible to use one or more, for example two or three, C1-C4 alkanols, it is preferred to use only one C1-C4 alkanol.

[0026] Preferably, the alkanol is methanol, ethanol, 1-propanol or 2-propanol, or a mixture thereof. Particularly preferred are methanol, 2-propanol, or a mixture thereof. Most particularly preferred is 2-propanol.

[0027] In a preferred embodiment, the content of the C1 to C4 alkanol in the composition is 98 mass % to 99.9 mass %, and together with ammonia, it accounts for 100 mass % of the composition.

[0028] composition The composition is mainly composed of ammonia and an alkanol. As used herein, "mainly composed of" means that the content of other components does not affect the pattern collapse prevention speed and properties of the composition. This means that, depending on the nature of the other components, the content should be less than 1% by weight, preferably less than 0.5% by weight, more preferably less than 0.1% by weight, and most preferably less than 0.01% by weight.

[0029] In a preferred embodiment, the anti-pattern collapse cleaning (APCC) composition consists primarily of dissolved alkanol and ammonia.

[0030] In another embodiment, the composition is a homogeneous (one-phase) composition.

[0031] Preferably, the composition is non-aqueous. As used herein, "non-aqueous" means that the composition can contain only a low amount of water, up to about 1% by weight. Preferably, the non-aqueous composition contains less than 0.5% by weight, more preferably less than 0.2% by weight, even more preferably less than 0.1% by weight, even more preferably less than 0.05% by weight, even more preferably less than 0.02% by weight, even more preferably less than 0.01% by weight, even more preferably less than 0.001% by weight. Most preferably, essentially no water is present in the composition. "Essentially" means that the water present in the composition does not significantly affect the performance of the additive in the non-aqueous composition in terms of pattern collapse of the processed substrate.

[0032] Applicable The composition according to the present invention can be applied to any substrate of pattern material, provided that the structure is prone to collapse due to its shape.

[0033] As an example, the patterned material layer may be as follows: (a) A patterned silicon layer; (b) a patterned barrier material layer comprising or consisting of ruthenium, titanium nitride, tantalum, or tantalum nitride; (c) a patterned multi-layer material layer comprising or consisting of layers of at least two different materials selected from the group consisting of silicon, polysilicon, low-k and ultra-low-k materials, high-k materials, semiconductors other than silicon and polysilicon, and metals; d) A patterned dielectric material layer comprising or consisting of a low-k or ultra-low-k material.

[0034] It is particularly preferred that the composition according to the invention is applied to a patterned silicon layer.

[0035] The method for manufacturing integrated circuit devices, electronic data storage devices, optical devices, micromachines and precision mechanical instruments includes the steps described below.

[0036] In the first step (a), a substrate is provided having a patterned layer of material with linear spatial dimensions of 50 nm or less, an aspect ratio of 4 or greater, or a combination thereof.

[0037] The substrate is preferably provided by a photolithographic process comprising the following steps: (i) providing a substrate with an immersion photoresist, EUV photoresist or electron photoresist layer; (ii) exposing the photoresist layer to actinic radiation through a mask with or without an immersion fluid; (iii) developing the exposed photoresist layer with a developer to obtain a pattern having a linewidth of 32 nm or less, a linear spatial dimension, and an aspect ratio of 4 or more; (iv) spin-drying the semiconductor substrate;

[0038] Any conventionally known immersion photoresist, EUV photoresist, or electron beam photoresist can be used. The immersion photoresist may already contain at least one siloxane additive or a combination thereof. In addition, the immersion photoresist may contain other non-ionic additives. Suitable non-ionic additives are described, for example, in US2008 / 0299487A1, page 6, paragraph

[0078] . Most preferably, the immersion photoresist is a positive resist.

[0039] Electron beam irradiation or extreme ultraviolet light with a wavelength of about 13.5 nm, preferably ultraviolet light with a wavelength of 193 nm, is used as actinic radiation.

[0040] In the case of immersion exposure, it is preferable to use ultrapure water as the immersion liquid.

[0041] Any conventional developer known in the art can be used to develop the exposed photoresist layer, preferably an aqueous developer containing tetramethylammonium hydroxide (TMAH).

[0042] Known equipment conventionally used in the semiconductor industry can be used to carry out photolithography steps in accordance with the method of the present invention.

[0043] In step (b), the substrate is contacted with an aqueous pretreatment composition containing or consisting essentially of 0.1 to 2% by weight of HF, preferably 0.25 to 1% by weight of HF. Preferably, the pretreatment composition consists of water and HF. The pretreatment is typically carried out for about 10 seconds to about 10 minutes, more preferably about 20 seconds to about 5 minutes, and most preferably about 30 seconds to about 3 minutes.

[0044] In step (c), the pretreatment composition of step (b) is removed from the substrate. This is usually done by rinsing the substrate with ultrapure water. This step is preferably performed once, but can be repeated if necessary.

[0045] In step (d), the substrate is contacted with a solvent-based composition primarily consisting of the APCC solution described herein. This APCC treatment is typically carried out for about 10 seconds to about 10 minutes, more preferably about 20 seconds to about 5 minutes, and most preferably about 30 seconds to about 3 minutes.

[0046] Typically, all steps (a) to (d) can be performed at any temperature from 10 to 40°C or higher. At higher temperatures, the amount of ammonia is quickly reduced by evaporation, and the composition is not stable. Lower temperatures are generally possible, but require intensive cooling. Temperatures between 10 and 35°C are preferred, with temperatures between 15 and 30°C being more preferred.

[0047] In step (e), the solution is removed from the substrate. Any known method commonly used to remove liquids from solid surfaces can be employed. In a preferred embodiment, this is done as follows: (i) contacting the substrate with a polar protic solvent, preferably a C1-C4 alkanol, most preferably 2-propanol, methanol, or ethanol; (ii) evaporating the polar protic solvent of step (i), preferably in the presence of an inert gas, which is preferably nitrogen.

[0048] All percentages, ppm or equivalent values ​​refer to weight relative to the total weight of the respective composition unless otherwise indicated. All citations are incorporated herein by reference.

[0049] The following examples further illustrate the invention without limiting its scope.

[0050] Example Some experiments were carried out using ammonia in 2-propanol and methanol.

[0051] To prepare a solution of ammonia in 2-propanol (IPA) at the desired concentration, first add the desired amount of a 4% ammonia in IPA stock solution (available from TCI) to a beaker. Then, add IPA to bring the total to 100 g. The solution was then stirred at 300 rpm for at least 3 minutes before use.

[0052] To prepare a solution of ammonia in methanol at the desired concentration, first add the desired amount of a 7N stock solution of ammonia in methanol (available from Acros) to a beaker. Methanol was then added to bring the total volume to 100 g. The solution was then stirred at 300 rpm for at least 3 minutes before use.

[0053] The pattern collapse performance of the formulation during drying was measured using a patterned silicon wafer with a circular nanopillar pattern. The (aspect ratio) AR20 pillars used in the test were 600 nm high and 30 nm in diameter. The pitch size was 90 nm. A 1 x 1 cm wafer piece was processed in the following order, without drying in between:

[0054] 50 seconds of immersion in 0.9% dilute hydrofluoric acid (DHF), ·60 seconds immersion in ultrapure water (UPW), 30 seconds of 2-propanol (isopropanol, IPA) immersion Immersion in a composition consisting of ammonia and 2-propanol in the amount shown in Table 1 at room temperature for 60 seconds, ·60 seconds IPA soak, N2 blow drying.

[0055] The dried silicon wafers were analyzed by top-down SEM, and the uncollapsed fraction is shown in Table 1. Because collapse varied from the center to the edge, only structures taken from essentially the same center-to-edge distance were compared. In the experiments, similar, and if possible, identical stiffness values ​​were chosen to evaluate the solution's performance in terms of uncollapsed fraction. The pillar stiffness was 54 mN / m.

[0056] [Table 1]

[0057] From Table 1, it can be seen that Example compositions 2 to 6 and 8 to 10 exhibit beneficial effects on the degree of pattern collapse compared to compositions using only 2-propanol or methanol.

[0058] In Example 11, the 50-second immersion in 0.9 mass % dilute hydrofluoric acid (DHF) was omitted.

[0059] Comparative Examples 11 and 12 show some comparative experiments using solvent-based pattern collapse prevention compositions according to WO2019 / 224032A. The compositions according to the present invention containing ammonia show a much higher percentage of uncollapsed pillars than those of WO2019 / 224032A.

Claims

1. (a) 0.1 to 3 mass % ammonia; (b) C １ ~C ４ Alkanols and It consists of A method of using the composition for treating a substrate having a patterned material layer with linear spatial dimensions of 50 nm or less, an aspect ratio of 4 or more, or a combination thereof to prevent pattern collapse.

2. C in the composition １ ~C ４ 2. The use according to claim 1, wherein the amount of alkanol is 98 to 99.9% by weight, which together with ammonia adds up to 100%.

3. C １ ~C ４ The use according to any one of claims 1 or 2, wherein the alkanol is selected from methanol, ethanol, 1-propanol and 2-propanol.

4. 4. Use according to any one of claims 1 to 3, wherein the amount of ammonia in the composition is between 0.5 and 2.5% by weight.

5. 5. The use according to any one of claims 1 to 4, wherein the substrate comprises a patterned layer of material having linear spatial dimensions of linewidths of 32 nm or less and an aspect ratio of 8 or more.

6. The following process: (a) providing a substrate comprising a patterned material layer having linear spatial dimensions of 50 nm or less, an aspect ratio of 4 or greater, or a combination thereof; (b) contacting the substrate with an aqueous pretreatment composition comprising 0.1 to 2 wt. % HF; (c) removing the aqueous pretreatment composition from the substrate; (d) contacting the substrate with an APCC composition consisting of: (i) 0.1 to 3% by weight of ammonia; (ii) C １ ~C ４ Alkanols, (e) removing the APCC composition from the substrate; and methods for manufacturing integrated circuit devices, electronic data storage devices, optical devices, micromachines and precision mechanical devices.

7. The method of claim 6, wherein the aqueous pretreatment composition consists essentially of water and HF.

8. C in the APCC composition １ ~C ４ 8. The method of claim 6, wherein the amount of alkanol is from 98 to 99.9% by weight, which together with ammonia adds up to 100%.

9. C １ ~C ４ 9. The process according to any one of claims 6 to 8, wherein the alkanol is selected from methanol, ethanol, 1-propanol and 2-propanol.

10. 10. The method according to any one of claims 6 to 9, wherein the amount of ammonia in the APCC composition is 0.5 to 2.5% by weight.

11. The following process: (i) contacting the substrate with a polar protic solvent; (ii) evaporating the polar protic solvent of step (i); The method according to any one of claims 6 to 10, wherein the aqueous APCC composition is removed from the substrate by

12. Step (a) is the following step: (i) providing a substrate with an immersion photoresist, EUV photoresist or e-beam photoresist layer; (ii) exposing the photoresist layer to actinic radiation through a mask with or without an immersion fluid; (iii) developing the exposed photoresist layer with a developer to obtain a pattern having a linewidth of 50 nm or less, a linear spatial dimension, and an aspect ratio of 4 or more; (iv) spin-drying the semiconductor substrate; 12. The method of any one of claims 6 to 11, comprising:

13. 13. The method of any one of claims 6 to 12, wherein any of steps (a), (b), (c) and (d) is carried out for 20 seconds to 5 minutes.

14. 14. The method of any one of claims 6 to 13, wherein the patterned material layer has linear spatial dimensions of linewidths of 32 nm or less and aspect ratios of 8 or greater.

15. 15. The method of any one of claims 6 to 14, wherein the patterned material layer is selected from the group consisting of a patterned silicon layer, a patterned barrier material layer, a patterned multilayer material layer, and a patterned dielectric material layer.

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