阅读说明：本技术 用于在处理具有50nm或更小的线距尺寸的图案化材料时避免图案塌陷的包含硼型添加剂的组合物 (Compositions comprising boron-based additives for avoiding pattern collapse when processing patterned materials having line-space dimensions of 50nm or less ) 是由 S·奇霍尼 D·勒夫勒 M·布里尔 F·皮龙 L·恩格布莱希特 M·伯格勒 P·维尔克 于 2020-04-03 设计创作，主要内容包括：本发明涉及一种非水性组合物,其包含：(a)有机溶剂,(b)至少一种式I的添加剂：其中R～(1)、R～(2)、R～(3)和R～(4)独立选自C-(1)-C-(10)烷基、C-(1)-C-(11)烷基羰基、C-(6)-C-(12)芳基、C-(7)-C-(14)烷芳基和C-(7)-C-(14)芳烷基；n为0或1。(The present invention relates to a non-aqueous composition comprising: (a) an organic solvent, (b) at least one additive of formula I: wherein R is 1 、R 2 、R 3 And R 4 Is independently selected from C 1 ‑C 10 Alkyl radical, C 1 ‑C 11 Alkylcarbonyl group, C 6 ‑C 12 Aryl radical, C 7 ‑C 14 Alkylaryl and C 7 ‑C 14 Aralkyl group; n is 0 or 1.)

1. A non-aqueous composition comprising:

(a) an organic solvent, and a solvent mixture comprising an organic solvent,

(b) at least one additive of formula I:

wherein R is¹、R²、R³And R⁴Is independently selected from C₁-C₁₀Alkyl radical, C₁-C₁₁Alkylcarbonyl group, C₆-C₁₂Aryl radical, C₇-C₁₄Alkylaryl and C₇-C₁₄Aralkyl group; n is 0 or 1.

2. The composition of claim 1, wherein the organic solvent is a polar protic organic solvent.

3. The composition of claim 1, wherein the organic solvent is linear or branched C₁-C₁₀An alkanol.

4. The composition according to any of the preceding claims, wherein the water content in the non-aqueous composition is below 0.1 wt.%.

5. The composition of any preceding claim, wherein the non-aqueous composition consists essentially of the organic solvent and the at least one additive of formula I.

6. The composition of any one of the preceding claims, wherein R¹、R²、R³And R⁴Is selected from C₁-C₆Alkyl radical, C₁-C₇Alkylcarbonyl, phenyl, C₇-C₁₀Alkylaryl and C₇-C₁₀An aralkyl group.

7. The composition of any one of the preceding claims, wherein n is 0.

8. The composition of any preceding claim, wherein the additive is selected from the group consisting of boron triacetate, tribenzylborate, trimethoxyborate, triethoxyborate, and tri-2-propoxyborate.

9. Use of the composition of any of claims 1-9 for treating a substrate having a patterned material layer having a pitch dimension of 50nm or less, an aspect ratio of greater than or equal to 4, or a combination thereof.

10. A method of fabricating integrated circuit devices, optical devices, micro-mechanical and mechanical precision devices, the method comprising the steps of:

(1) providing a substrate having a patterned material layer having a line spacing dimension of 50nm or less, an aspect ratio of greater than or equal to 4, or a combination thereof,

(2) contacting the substrate at least once with a composition according to any one of claims 1-9, and

(3) removing the non-aqueous composition from contact with the substrate.

11. The method of claim 11, wherein the patterned material layer has a line pitch dimension of 32nm or less and an aspect ratio of 10 or more.

12. The method of claim 11 or 12, wherein the patterned material layer is selected from the group consisting of a patterned developed photoresist layer, a patterned barrier material layer, a patterned multi-stack material layer, and a patterned dielectric material layer.

Background

In the process of manufacturing ICs with LSI, VLSI and ULSI, patterned material layers are produced by lithographic techniques, such as patterned photoresist layers, patterned barrier material layers comprising or consisting of titanium nitride, tantalum or tantalum nitride, patterned multi-stack material layers comprising or consisting of stacks of, for example, alternating layers of polysilicon and silicon dioxide or silicon nitride, and patterned dielectric material layers comprising or consisting of silicon dioxide or low-k or ultra-low-k dielectric materials. Today, the patterned material layer comprises structures with dimensions even below 22nm and with high aspect ratios.

However, regardless of the exposure technique, wet chemical treatment of small patterns involves a number of problems. As technology advances and dimensional requirements become more stringent, the patterns are required to include relatively thin and tall features or features of the device structure, i.e., features having a high aspect ratio, on the substrate. These structures may suffer from bending and/or collapse, particularly during the spin drying process, due to excessive capillary forces of the liquid or solution of rinse solution bulk di water remaining in the chemical rinse and spin drying processes and disposed between adjacent patterned structures.

Due to the shrinking dimensions, the removal of particles and plasma etch residues in order to obtain defect-free patterned structures is also a critical factor. This applies not only to photoresist patterns, but also to other patterned material layers generated during the fabrication of optical devices, micro-machines and mechanical precision devices.

WO 2012/027667a2 discloses a method of modifying the surface 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 forces acting on the high aspect ratio features when a rinse solution is contacted with the modified surface are sufficiently minimized to prevent bowing or collapse of the high aspect ratio features at least during removal of the rinse solution or at least during drying of the high aspect ratio features.

WO 2019/086374 discloses a non-aqueous composition comprising a silicone-based anti-pattern-collapse additive. Unpublished european patent application 18190173.7 discloses a non-aqueous composition comprising a phosphonic acid type additive. Unpublished european patent application 19168153.5 discloses a non-aqueous composition comprising an ammonia-activated H-silane type additive.

However, there is still a need for a composition that is effective in preventing pattern collapse of sub-50 nm structures.

It is an object of the present invention to provide a method of manufacturing an integrated circuit with 50nm and smaller nodes, in particular 32nm and smaller nodes, in particular 22nm and smaller nodes, which method no longer exhibits the disadvantages of the prior art manufacturing methods.

In particular, the compounds of the present invention will allow for chemical rinsing of patterned material layers comprising high aspect ratios and line-space (line-space) dimensions of 50nm and less, in particular 32nm and less, especially 22nm and less, without causing pattern collapse.

Summary of The Invention

The present invention completely avoids all the disadvantages of the prior art by using a non-aqueous composition comprising an organic solvent in combination with the boron-based non-ionic additive described herein.

A first embodiment of the present invention is a non-aqueous composition comprising:

(a) an organic solvent, and a solvent mixture comprising an organic solvent,

(b) at least one additive of formula I:

wherein R is¹、R²、R³And R⁴Is independently selected from C₁-C₁₀Alkyl radical, C₁-C₁₁Alkylcarbonyl group, C₆-C₁₂Aryl radical, C₇-C₁₄Alkylaryl and C₇-C₁₄Aralkyl group; n is 0 or 1.

Another embodiment of the present invention is the use of a composition described herein for treating a substrate having a patterned material layer having a pitch dimension of 50nm or less, an aspect ratio of greater than or equal to 4, or a combination thereof.

Yet another embodiment of the present invention is a method of fabricating integrated circuit devices, optical devices, micro-mechanical and mechanical precision devices, the method comprising the steps of:

(1) providing a substrate having a patterned material layer having a line spacing dimension of 50nm or less, an aspect ratio of greater than or equal to 4, or a combination thereof,

(2) contacting the substrate at least once with a non-aqueous composition as described herein, and

(3) removing the non-aqueous composition from contact with the substrate.

The composition comprising a combination of an organic solvent (preferably an alcohol) and a boron-type additive is particularly suitable for use in the anti-pattern collapse treatment of a substrate comprising a pattern having a pitch dimension of 50nm or less, particularly 32nm or less, most particularly 22nm or less. Furthermore, the compositions of the present invention are particularly useful for aspect ratios of greater than or equal to 4 without causing pattern collapse. Last but not least, if a protic organic solvent, in particular an alcohol, is used as solvent, the composition has excellent compatibility with the substrate comprising polyvinyl chloride.

Cleaning or rinsing solutions comprising a combination of a polar solvent and a boron-type additive are generally useful for avoiding pattern collapse of photoresist structures as well as non-photoresist patterns with High Aspect Ratio Stacks (HARS), particularly patterned multi-stack material layers comprising or consisting of stacks of alternating polysilicon and silicon dioxide or silicon nitride layers.

Detailed Description

The present invention relates to a composition that is particularly suitable for the manufacture of patterned materials comprising sub-50 nm sized features, such as Integrated Circuit (IC) devices, optical devices, micro-mechanical and mechanical precision devices, in particular IC devices.

Any conventional and known substrate for manufacturing IC devices, optical devices, micro-mechanical and mechanical precision devices may be used in the method of the present invention. Preferably, the substrate is a semiconductor substrate, more preferably a silicon wafer, which is commonly used for the manufacture of IC devices, in particular devices including ICs with LSI, VLSI and ULSI.

The composition is particularly suitable for processing substrates having a patterned material layer with line pitch dimensions of 50nm and less, in particular 32nm and less, especially 22nm and less, i.e. a patterned material layer for sub-22 nm technology nodes. The layer of patterned material preferably has an aspect ratio of greater than 4, preferably greater than 5, more preferably greater than 6, even more preferably greater than 8, even more preferably greater than 10, even more preferably greater than 12, even more preferably greater than 15, even more preferably greater than 20. The smaller the pitch dimension and the higher the aspect ratio, the more advantageous is the use of the compositions described herein.

The compositions of the present invention can be used on substrates of any patterned material, as long as the structure tends to collapse due to its geometry.

For example, the patterned material layer may be:

(a) a patterned silicon oxide or silicon nitride coated Si layer,

(b) a patterned layer of barrier material comprising or consisting of ruthenium, cobalt, titanium nitride, tantalum or tantalum nitride,

(c) a patterned multi-stack material layer comprising or consisting of a layer of at least two different materials selected from the group consisting of silicon, polysilicon, silicon dioxide, SiGe, low-k and ultra-low-k materials, high-k materials, semiconductors other than silicon and polysilicon, and metals, and

(d) a patterned layer of dielectric material comprising or consisting of silicon dioxide or a low-k or ultra-low-k dielectric material.

Organic solvent

The anti-pattern collapse composition comprises an organic solvent, preferably a polar protic organic solvent.

It has been surprisingly found that even small amounts of water can affect the pattern collapse resistance properties of the subject compositions. It is therefore important that the composition, and primarily the organic solvent present in the composition of the invention, is non-aqueous. Polar protic organic solvents such as isopropanol usually have a rather high residual water content, unless removed by drying, due to their hygroscopic nature.

As used herein, "non-aqueous" means that the composition may contain only a low amount of water up to about 1% by weight. Preferably, the non-aqueous composition comprises less than 0.5 wt.%, more preferably less than 0.2 wt.%, even more preferably less than 0.1 wt.%, even more preferably less than 0.05 wt.%, even more preferably less than 0.02 wt.%, even more preferably less than 0.01 wt.%, even more preferably less than 0.001 wt.% of water. Most preferably, substantially no water is present in the composition. Here, "substantially" means that the water present in the composition has no significant effect on the performance of the additive in a non-aqueous solution with respect to pattern collapse of the substrate to be treated.

The organic solvent must have a sufficiently low boiling point to be removed by heating without adversely affecting the substrate treated with the composition. For typical substrates, the boiling point of the organic solvent should be 150 ℃ or less, preferably 100 ℃ or less.

Preferably, the solvent consists essentially of one or more organic solvents, which may be protic or aprotic organic solvents. Preferred are one or more polar protic organic solvents, most preferred are single polar protic organic solvents.

As used herein, a "polar aprotic organic solvent" is an organic solvent having no acidic hydrogen (i.e., no or no contribution of hydrogen ions), a dipole moment of 1.7 or greater.

Typical polar aprotic organic solvents are, but are not limited to, (a) ketones such as but not limited to acetone, (b) lactones such as but not limited to gamma-butyrolactone, (c) lactams such as but not limited to N-methyl-2-pyrrolidone, (d) nitriles such as but not limited to acetonitrile, (e) nitro compounds such as but not limited to nitromethane, (f) tertiary carboxylic acid amides such as but not limited to dimethylformamide, (g) urea derivatives such as but not limited to tetramethylurea or Dimethylpropyleneurea (DMPU), (h) sulfoxides such as but not limited to Dimethylsulfoxide (DMSO), (i) sulfones such as but not limited to sulfolane, (h) carbonates such as but not limited to dimethyl carbonate or ethylene carbonate.

As used herein, a "polar protic organic solvent" is an organic solvent that comprises acidic hydrogen (i.e., can donate hydrogen ions).

Typical polar protic organic solvents are, but are not limited to, (a) C₁-C₁₀An alcohol, (b) a primary or secondary amine, a carboxylic acid such as, but not limited to, formic acid or acetic acid, or (c) a primary or secondary amide such as, but not limited to, formamide.

Preferred organic solvents are linear, branched or cyclic aliphatic alcohols, in particular linear or branched alkanols, which comprise at least one hydroxyl group. Preferred alkanols are methanol, ethanol, 1-propanol, 2-propanol (isopropanol) or butanol. Most preferred is 2-propanol.

An additive of the formula I

The borate ester additives of the present invention (also referred to as additives, or more specifically as boron alkoxylates or boron aryloxides) may be selected from formula I:

here, R¹、R²、R³And R⁴Can be independently selected from C₁-C₁₀Alkyl radical, C₁-C₁₁Alkylcarbonyl group, C₆-C₁₂Aryl radical, C₇-C₁₄Alkylaryl and C₇-C₁₄An aralkyl group. Preferably, R¹、R²、R³And R⁴Can be selected from C₁-C₈Alkyl radical, C₁-C₉Alkylcarbonyl group, C₆-C₁₀Aryl radical, C₇-C₁₂Alkylaryl and C₇-C₁₂An aralkyl group. More preferably, R¹、R²、R³And R⁴Can be selected from C₁-C₆Alkyl radical, C₁-C₇Alkylcarbonyl, phenyl, C₇-C₁₀Alkylaryl and C₇-C₁₀An aralkyl group. Even more preferably, R¹、R²、R³And R⁴Can be selected from C₁-C₄Alkyl radical, C₁-C₅Alkylcarbonyl, phenyl, C₇-C₈Alkylaryl and C₇-C₈An aralkyl group. Most preferably, the group R¹、R²、R³And R⁴Can be selected from methyl, ethyl, 1-propyl, 2-propyl, acetyl and phenyl.

n may be 0 or 1, preferably 0.

In a particularly preferred embodiment, the additive is selected from the group consisting of boron triacetate, tribenzylborate, trimethoxyborate, triethoxyborate, and tri-2-propoxyborate.

The concentration should be high enough to properly prevent pattern collapse, but should be as low as possible for economic reasons. The concentration of the additives of formulae I, II, III, and IV in the non-aqueous solution may generally be from about 0.00005 to about 3 weight percent. Preferably, the concentration of the additive is from about 0.00005 to about 1.0 weight percent, more preferably from about 0.0005 to about 0.5 weight percent, even more preferably from 0.0005 to 0.1 weight percent, even more preferably from 0.001 to 0.1 weight percent, and most preferably from 0.002 to 0.1 weight percent, based on the total weight of the composition.

One or more additives may be present in the composition, however it is preferred to use only one additive of formula I.

Other additives

Other additives may be present in the cleaning solutions of the present invention. Such additives may be:

(I) buffer components for pH adjustment, such as but not limited to (NH)₄)₂CO₃/NH₄OH、Na₂CO₃/NaHCO₃tris/HCl, Na₂HPO₄/NaH₂PO₄Or an organic acid such as acetic acid and the like, methanesulfonic acid,

(II) one or more further additives, nonionic or anionic, for improving the surface tension and solubility of the mixture, or

(III) a dispersant for preventing the removed soil or polymer particles from re-attaching to the surface.

Preferably, the non-aqueous composition consists essentially of an organic solvent, preferably a polar protic organic solvent, and the at least one additive of formula I.

Applications of

The compositions described herein can be used to process a substrate having a patterned material layer with a line pitch dimension of 50nm or less, an aspect ratio of greater than or equal to 4, or a combination thereof.

The compositions described herein may be used in a method of fabricating integrated circuit devices, optical devices, micro-machines and mechanical precision devices, the method comprising the steps of:

(1) providing a substrate having a patterned material layer having a line-space dimension of 50nm and less and an aspect ratio of greater than or equal to 4,

(2) contacting the substrate at least once with a non-aqueous solution comprising at least one borate additive as described herein, and

(3) removing the non-aqueous composition from contact with the substrate.

Preferably, the substrate is provided by a lithographic process comprising:

(i) providing a substrate having an immersion photoresist, EUV photoresist or electron beam photoresist layer,

(ii) the photoresist layer is exposed to actinic radiation through a mask with or without an immersion fluid,

(iii) developing the exposed photoresist layer with a developer solution to obtain a pattern having a line pitch dimension of 32nm and less and an aspect ratio of 10 or more,

(iv) applying the non-aqueous composition described herein to a developed patterned photoresist layer, and

(v) spin drying the semiconductor substrate after applying the non-aqueous composition.

Any conventional and known immersion photoresist, EUV photoresist, or electron beam photoresist may be used. The immersion photoresist may already contain at least one of said additives or a combination thereof. In addition, the immersion photoresist may contain other nonionic additives. Suitable nonionic additives are described, for example, in US 2008/0299487A1, page 6, paragraph [0078 ]. Most preferably, the immersion photoresist is a positive photoresist.

In addition to electron beam exposure or extreme ultraviolet radiation of about 13.5nm, UV radiation with a wavelength of 193nm is preferably used as actinic radiation.

In the case of immersion lithography, ultrapure water is preferably used as the immersion liquid.

The exposed photoresist layer can be developed using any conventional and known developer solution. Preferably, an aqueous developer solution comprising tetramethylammonium hydroxide (TMAH) is used.

Preferably, the chemical rinse solution is applied to the exposed and developed photoresist layer in the form of a puddle.

In a third step of the method, the non-aqueous solution is removed from contact with the substrate. Any known method commonly used for removing liquids from solid surfaces may be used.

For the lithographic process according to the method of the invention it is essential that the chemical rinse solution contains at least one siloxane additive.

The photolithography process according to the method of the present invention can be carried out using conventional and known equipment commonly used in the semiconductor industry.

Examples

A patterned silicon wafer with a circular pattern of nano-pillars was used to determine the pattern collapse performance of the formulation during drying. The AR 20 columns (aspect ratio) used for the test were 600nm in height and 30nm in diameter. The pitch size was 90 nm. 1X 1cm wafer pieces, treated in the following order without drying in between:

■ 30s diluted hydrofluoric acid (DHF) 0.9%,

■ 60s Ultra Pure Water (UPW),

■ 60s isopropyl alcohol (IPA) soak,

■ 60s a solution of the corresponding additive in a solvent is soaked at room temperature,

■ 60 the liquid is soaked in IPA for a period of time,

■N₂and (5) drying.

The water content of the solvent is less than 0.01% by weight.

The compositions of table 1 were used in the examples.

TABLE 1

Examples	Additive agent	Concentration [ weight%]	Organic solvent
				Comparative example 1	n/a	0	Isopropanol (I-propanol)
2	Tris-2-propoxybutyrate borate	0,05	Isopropanol (I-propanol)

Table 2 shows the dried silicon wafers and collapse statistics analyzed with top-down SEM for examples 1 and 2.

The pattern collapsed cluster size distribution was determined from the SEM image. The size of the clusters corresponds to the number of uncollapsed pillars comprised by each cluster. For example, if the wafer before processing contained 4 x 4 pillars and 8 remained uncollapsed, 4 collapsed into two clusters containing 2 pillars and 4 collapsed into one cluster containing 4 pillars, the ratio would be 8/11 single clusters, 2/11 double clusters, and 1/11 clusters with four pillars.

TABLE 2

Table 2 shows that the additives have a beneficial effect on the degree of pattern collapse compared to a solution without any additives.