Composition Comprising a Siloxane and an Alkane for Avoiding Pattern Collapse When Treating Patterned Materials with Line-Space Dimensions of 50 NM or Below

Abstract

Described herein is a non-aqueous composition including (a) an organic solvent; and (b) at least one additive of formulae I or II where R.sup.1 is H R.sup.2 is selected from the group consisting of H, C.sub.1 to C.sub.10 alkyl, C.sub.1 to C.sub.10 alkoxy, C.sub.6 to C.sub.10 aryl, and C.sub.6 to C.sub.10 aroxy, R.sup.3 is selected from the group consisting of R.sup.2, R.sup.4 is selected from the group consisting of C.sub.1 to C.sub.10 alkyl, C.sub.1 to C.sub.10 alkoxy, C.sub.6 to C.sub.10 aryl, and C.sub.6 to C.sub.10 aroxy, R.sup.10, R.sup.12 are independently selected from the group consisting of C.sub.1 to C.sub.19 alkyl and C.sub.1 to C.sub.10 alkoxy, m is 1, 2 or 3, and n is 0 or an integer from 1 to 100.

Claims

1. A non-aqueous composition essentially consisting of (a) an organic solvent selected from the group consisting of (i) a linear, branched or cyclic C.sub.5 to C.sub.12 alkane, and (ii) a benzene substituted by 1 to 3 C.sub.1 to C.sub.4 alkyl groups; and (b) at least one additive of formulae I or II ##STR00007## ##STR00008## wherein R.sup.1 is H R.sup.2 is selected from the group consisting of H, C.sub.1 to C.sub.10 alkyl, C.sub.1 to C.sub.10 alkoxy, C.sub.6 to C.sub.10 aryl, and C.sub.6 to C.sub.10 aroxy, R.sup.3 is selected from the group consisting of R.sup.2, R.sup.4 is selected from the group consisting of C.sub.1 to C.sub.10 alkyl, C.sub.1 to C.sub.10 alkoxy, C.sub.6 to C.sub.10 aryl, and C.sub.6 to C.sub.10 aroxy, R.sup.10, R.sup.12 are independently selected from the group consisting of C.sub.1 to C.sub.10 alkyl and C.sub.1 to C.sub.10 alkoxy, m is 1, 2 or 3, and n is 0 or an integer from 1 to 100.

2. The composition according to claim 1, wherein the organic solvent is selected from the group consisting of hexane, heptane, octane, nonane, and decane.

3. The composition according to claim 1, wherein the organic solvent is selected from the group consisting of toluene, 1,2-xylene, 1,3-xylene, 1,4-xylene, ethylbenzene, 1,2-diethylbenzene, 1,3- diethylbenzene, and 1,4- diethylbenzene.

4. The composition according to claim 1, wherein a content of water in the non-aqueous composition is lower than 0.1 % by weight.

5. The composition according to claim 1, wherein the at least one additive of formulae I or II is present in a concentration from 2.5 to 15% by weight.

6. The composition according to claim 1, wherein the at least one additive is a compound of formula I, wherein n is 0, 1 or 2.

7. The composition according to claim 1, wherein R.sup.2, R.sup.4, R.sup.10, and R.sup.12 are independently selected from the group consisting of methyl, methoxy, ethyl, ethoxy, propyl, and propoxy.

8. The composition according to claim 1, wherein the at least one additive is selected from the group consisting of trimethoxysilane, triethoxysilane, trimethylsilane, and triethylsilane.

9. A method of using the composition according to claim 1, the method comprising using the composition for treating substrates having patterned material layers having line-space dimensions of 50 nm or below, aspect ratios of greater than or equal to 4, or a combination thereof.

10. A method for manufacturing integrated circuit devices, optical devices, micromachines and mechanical precision devices, the method comprising (a) providing a substrate having patterned material layers having line-space dimensions of less than or equal to 50 nm, aspect ratios of greater than or equal to 4, or a combination thereof; (b) contacting the substrate with an aqueous pretreatment composition comprising ammonia and hydrogen peroxide; (c) removing the aqueous pretreatment composition from the substrate; (d) contacting the substrate at least once with the non-aqueous composition according to claim 1; and (e) removing the non-aqueous composition from the contact with the substrate.

11. The method according to claim 10, wherein the patterned material layers have line-space dimensions of less than or equal to 32 nm and aspect ratios of greater than or equal to 10.

12. The method according to claim 10, wherein the patterned material layers comprise silicon, silicon oxide or silicon nitride.

13. The method according to claim 10, wherein in step (b), from 0.1 to 5 % by weight ammonia (as NH.sub.4OH), and from 1 to 20 % by weight hydrogen peroxide are used.

14. The method according to claim 10, wherein the patterned material layers are selected from the group consisting of patterned multi-stack material layers and patterned dielectric material layers.

15. The composition according to claim 1, wherein the at least one additive of formulae I or II is present in a concentration from 3.5 to 12 % by weight.

16. The composition according to claim 1, wherein the at least one additive is a compound of formula I, wherein n is 0 or 1.

17. The method according to claim 10, wherein in step (b), from 0.5 to 3 % by weight ammonia (as NH.sub.4OH), and from 1 to 20 % by weight hydrogen peroxide are used.

18. The method according to claim 10, wherein in step (b), from 0.1 to 5 % by weight ammonia (as NH.sub.4OH), and from 5 to 17 % by weight hydrogen peroxide are used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0036] The present invention is directed to a composition particularly suitable for manufacturing patterned materials comprising sub 50 nm sized features like integrated circuit (IC) devices, optical devices, micromachines and mechanical precision devices, in particular IC devices.

[0037] Any customary and known substrates used for manufacturing IC devices, optical devices, micromachines and mechanical precision devices can be used in the process of the invention. Preferably, the substrate is a semiconductor substrate, more preferably a silicon wafer, which wafers are customarily used for manufacturing IC devices, in particular IC devices comprising ICs having LSI, VLSI and ULSI.

[0038] The composition is particularly suitable for treating substrates having patterned material layers having line-space dimensions of 50 nm and less, in particular, 32 nm and less and, especially, 22 nm and less, i.e. patterned material layers for the sub-22 nm technology nodes. The patterned material layers preferably have aspect ratios above 4, preferably above 5, more preferably above 6, even more preferably above 8, even more preferably above 10, even more preferably above 12, even more preferably above 15, even more preferably above 20. The smaller the line-space dimensions and the higher the aspect ratios are the more advantageous is the use of the composition described herein.

[0039] The composition according to the present invention may be applied to substrates of any patterned material as long as structures tend to collapse due to their geometry.

[0040] By way of example, the patterned material layers may be [0041] (a) patterned silicon oxide or silicon nitride coated Si layers, [0042] (b) patterned barrier material layers containing or consisting of ruthenium, cobalt, titanium nitride, tantalum or tantalum nitride, [0043] (c) patterned multi-stack material layers containing or consisting of layers 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 [0044] d) patterned dielectric material layers containing or consisting of silicon dioxide or low-k or ultra-low-k dielectric materials.

[0045] Particularly preferred patterned material layers may be [0046] patterned silicon layers, [0047] silicon oxide or silicon nitride coated Si layers, and [0048] patterned multi-stack material layers containing or consisting of layers 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 [0049] patterned dielectric material layers containing or consisting of silicon dioxide or low-k or ultra-low-k dielectric materials.

[0050] These materials may not be treated with an HF pretreatment solution but require an alkaline SC1 pretreatment and the effect of the composition and method according to the present invention is particularly pronounced for such materials and pretreatment.

Solvent

[0051] The non-aqueous anti-pattern-collapse composition comprises a non-polar organic solvent which may be either (i) a linear, branched or cyclic C.sub.5 to C.sub.12 alkane, or (ii) a benzene substituted by 1 to 3 C.sub.1 to C.sub.4 alkyl groups, or (iii) a combination thereof.

[0052] Even if non-polar organic solvents have a low hygroscopicity and contain a rather low amount of residual water, it may nevertheless be advantageous to remove the water residues by drying before its use in the anti-pattern-collapse compositions.

[0053] As used herein, “non-aqueous” means that the composition may only contain low amounts of water up to about 1 % by weight. Preferably the non-aqueous composition comprises 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 of water. Most preferably essentially no water is present in the composition. “Essentially” here means that the water present in the composition does not have a significant influence on the performance of the additive in the non-aqueous solution with respect to pattern collapse of the substrates to be treated.

[0054] The organic solvents need to have a boiling point sufficiently low to be removed by heating without negatively impacting the substrate treated with the composition. For typical substrates, the boiling point of the organic solvent should be 150° C. or below, preferably 100° C. or below.

[0055] In a preferred embodiment the solvent essentially consists of one or more non-polar organic solvents, preferably a single non-polar organic solvent. I.e. no other solvent except the non-polar solvent(s) is present in the composition.

[0056] In another preferred embodiment the non-polar organic solvent may be linear, branched or cyclic hexane, heptane, octane, nonane, decane, or mixtures thereof; particularly linear, branched or cyclic hexane, heptane, or octane. The most preferred C.sub.5 to C.sub.12 alkanes are linear or branched heptane, particularly n-heptane, cyclohexane and cycloheptane, methylcyclohexane.

[0057] In yet another preferred embodiment the non-polar organic solvent is selected from toluene, 1,2-xylene, 1,3-xylene, 1,4-xylene, ethylbenzene, 1,2-diethylbenzene, 1,3- diethylbenzene, 1,4-diethylbenzene, particularly 1,2-xylene, 1,3-xylene, 1,4-xylene, or mixtures thereof.

Additives of Formula I or II

[0058] In a first embodiment the non-ionic H-silane additive according to the present invention (also referred to as additive or more specifically silane or siloxane) may be selected from formula I or II:

##STR00005##

##STR00006##

[0059] Herein R.sup.1 is H, i.e. the additive according to the invention is an H-silane or H-siloxane. The H-silane or H-siloxane show a much better performance compared to other silanes or siloxanes like tetraethyl orthosilicate.

[0060] In formula I and II R.sup.2 may be selected from H, C.sub.1 to C.sub.10 alkyl, C.sub.1 to C.sub.10 alkoxy, C.sub.6 to C.sub.12 aryl, and C.sub.6 to C.sub.10 aroxy. Preferably R.sup.2 may be selected from C.sub.1 to C.sub.8 alkyl, C.sub.1 to C.sub.8 alkoxy. More preferably R.sup.2 may be selected from C.sub.1 to C.sub.6 alkyl and C.sub.1 to C.sub.6 alkoxy. Most preferably R.sup.2 may be selected from C.sub.1 to C.sub.4 alkyl and C.sub.1 to C.sub.4 alkoxy. Most preferred groups R.sup.2 may be selected from methyl, ethyl, methoxy and ethoxy.

[0061] R.sup.3 may be selected from H, C.sub.1 to C.sub.10 alkyl, C.sub.1 to C.sub.10 alkoxy, C.sub.6 to C.sub.10 aryl, and C.sub.6 to C.sub.10 aroxy. Preferably R.sup.3 may be selected from H, C.sub.1 to C.sub.8 alkyl, C.sub.1 to C.sub.8 alkoxy. More preferably R.sup.3 may be selected from H, C.sub.1 to C.sub.6 alkyl and C.sub.1 to C.sub.6 alkoxy. Even more preferably R.sup.3 may be selected from H, C.sub.1 to C.sub.4 alkyl and C.sub.1 to C.sub.4 alkoxy. Most preferred groups R.sup.3 may be selected from H, methyl, ethyl, methoxy and ethoxy.

[0062] R.sup.4 may be selected from C.sub.1 to C.sub.10 alkyl, C.sub.1 to C.sub.10 alkoxy, C.sub.6 to C.sub.10 aryl, and C.sub.6 to C.sub.10 aroxy. Preferably R.sup.4 may be selected from C.sub.1 to C.sub.8 alkyl, C.sub.1 to C.sub.8 alkoxy,. More preferably R.sup.4 may be selected from C.sub.1 to C.sub.6 alkyl and C.sub.1 to C.sub.6 alkoxy. Most preferably R.sup.4 may be selected from C.sub.1 to C.sub.4 alkyl and C.sub.1 to C.sub.4 alkoxy. Most preferred groups R.sup.4 may be selected from methyl, ethyl, methoxy and ethoxy.

[0063] R.sup.10, R.sup.12 may be independently selected from C.sub.1 to C.sub.10 alkyl and C.sub.1 to C.sub.10 alkoxy. Preferably R.sup.10, R.sup.12 and R.sup.4 may be selected from C.sub.1 to C.sub.8 alkyl, C.sub.1 to C.sub.8 alkoxy,. More preferably R.sup.10 and R.sup.12 may be selected from C.sub.1 to C.sub.6 alkyl and C.sub.1 to C.sub.6 alkoxy. Most preferably R.sup.10 and R.sup.12 may be selected from C.sub.1 to C.sub.4 alkyl and C.sub.1 to C.sub.4 alkoxy. Most preferred groups R.sup.4 may be selected from methyl, ethyl, methoxy and ethoxy.

[0064] In formula I n may be 0 or an integer from 1 to 100, preferably 0, or an integer from 1 to 50, even more preferably 0 or an integer from 1 to 20, most preferably 0. In formula II m may be 1, 2 or 3, preferably 1.

[0065] Preferably R.sup.2, R.sup.4, R.sup.10, and R.sup.12 are independently selected from methyl, methoxy, ethyl, ethoxy, propyl, and propoxy.

[0066] In a particular preferred embodiment the additive is selected from trimethoxysilane, triethoxysilane, trimethylsilane, and triethylsilane.

[0067] The concentration should be sufficiently high to properly prevent pattern collapse but should be as low as possible for economic reasons. The concentration of the additives of formula I or II in the non-aqueous solution may generally be in the range of about 0.00005 to about 15% by weight. Preferably the concentration of the additive if from about 0.001 to about 12% by weight, more preferably from about 0.005 to about 12% by weight, even more preferably from about 0.05 to about 10% by weight, and most preferably 0.1 to 5% by weight, the weight percentages being based on the overall weight of the composition.

[0068] There may be one or more additives in the composition, however it is preferred to use only one additive of formula I or II.

Further Additives

[0069] Further additive may be present in the cleaning solution according to the present invention. Such additives may be [0070] (I) buffer components for pH adjustment such as but not limited to (NH.sub.4).sub.2CO.sub.3/NH40H, Na.sub.2CO.sub.3/NaHCO.sub.3, tris-hydroxymethyl-aminomethane/HCI, Na.sub.2HPO.sub.4/NaH.sub.2PO.sub.4, or organic acids like acetic acid etc., methanesulfonic acid; [0071] (II) one or more further additives, either non-ionic, or, anionic to improve surface tension and solubility of the mixture; [0072] (III) dispersants to prevent the surface re-attachment of the removed particles of dirt or polymer; [0073] (IV) ammonia, as described in non-published European Patent application No. 19168153.5 to further activate the H-silane additive described above. Such activation is generally possible by adding from about 0.05 to about 8 % by weight of ammonia to the solution. Below 0.05% by weight the activation is insufficient, using more than about 8% by weight is difficult to achieve due to limited solubility of ammonia in the protic organic solvent. Preferably 0.2 to 6% by weight, more preferably from 0.3 to 4% by weight, most preferably 0.5 to 2% by weight are used for the activation.

Rinsing Solution

[0074] Preferably the non-aqueous composition consists essentially of the organic non-polar solvent, the at least one additive of formula I or II, optionally ammonia, and reaction products thereof.

[0075] If ammonia is used, it is preferably added in situ just before its use. Therefore, it is advantageous to supply the compositions as a two-component kit comprising (a) ammonia dissolved in the organic protic solvent and optionally a C.sub.5 to C.sub.12 alkane, and (b) at least one additive of formulae I or II as described herein.

Application

[0076] The compositions described herein may be used for treating substrates having patterned material layers having line-space dimensions of 50 nm or below, aspect ratios of greater or equal 4, or a combination thereof.

[0077] The compositions described herein may be used in a method for manufacturing integrated circuit devices, optical devices, micromachines and mechanical precision devices, the said method comprising the steps of [0078] (a) providing a substrate having patterned material layers having line-space dimensions of 50 nm or below, aspect ratios of greater or equal 4, or a combination thereof, [0079] (b) contacting the substrate with an aqueous pretreatment composition comprising ammonia and hydrogen peroxide; [0080] (c) removing the aqueous pretreatment composition from the substrate; [0081] (d) contacting the substrate at least once with a non-aqueous composition according to anyone of claims 1 to 8, and [0082] (e) removing the non-aqueous composition from the contact with the substrate.

[0083] In a first step (a) a substrate having patterned material layers having line-space dimensions of 50 nm or below, aspect ratios of greater or equal 4, or a combination thereof is provided.

[0084] The substrate is preferably provided by a photolithographic process comprising the steps of [0085] (i) providing the substrate with an immersion photoresist, EUV photoresist or eBeam photoresist layer, [0086] (ii) exposing the photoresist layer to actinic radiation through a mask with or without an immersion liquid, [0087] (iii) developing the exposed photoresist layer with a developer solution to obtain a pattern having line-space dimensions of 32 nm and less and an aspect ratio of 4 or more, [0088] (iv) spin drying the semiconductor substrate after the application of the composition.

[0089] Any customary and known immersion photoresist, EUV photoresist or eBeam photoresist can be used. The immersion photoresist may already contain at least one of the siloxane additives or a combination thereof. Additionally, the immersion photoresist may contain other nonionic additives. Suitable nonionic additives are described, for example, in US 2008/0299487 A1, page 6, paragraph [0078]. Most preferably, the immersion photoresist is a positive resist.

[0090] Beside e-Beam exposure or extreme ultraviolet radiation of approx. 13.5 nm, preferably, UV radiation of the wavelength of 193 nm is used as the actinic radiation.

[0091] In case of immersion lithography preferably, ultra-pure water is used as the immersion liquid.

[0092] Any customary and known developer solution can be used for developing the exposed photoresist layer. Preferably, aqueous developer solutions containing tetramethylammonium hydroxide (TMAH) are used.

[0093] Customary and known equipment customarily used in the semiconductor industry can be used for carrying out the photolithographic process in accordance with the method of the invention.

[0094] In step (b) a so called SC1 pretreatment is performed. Preferably such aqueous SC1 pretreatment composition comprises from 0.1 to 5 % by weight, preferably from 0.5 to 3 % by weight ammonia (as NH.sub.4OH), and 1 to 20 % by weight, preferably from 5 to 17 % by weight hydrogen peroxide. The pretreatment is usually performed for about 10 s to about 10 min, more preferably from about 20 s to about 5 min, most preferably from about 30 s to about 3 min.

[0095] As used herein, “aqueous” means that the solvent comprises water, preferably deionized water and, most preferably ultrapure water as the main solvent. The aqueous composition may contain water-miscible polar organic solvents, albeit only in such minor amounts that do not jeopardize the aqueous nature of the composition. It is preferred that the solvent essentially consists of water, preferably deionized water and, most preferably ultrapure water. Example of ultrapure water with concentration of 5 ppt (ng/kg), or better, anion concentration 5 ppb (ng/g), or better, total organic content (TOC) 50 ppb (ng/g), or better and contains particles of >0.2 mm under 10000 per ml.

[0096] 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. Preferably this step is preferably performed once, but may also be repeated, if required.

[0097] In step (d) the substrate is at least once brought into contact with the non-aqueous composition as described herein. This APCC treatment is usually performed for about 10 s to about 10 min, more preferably from about 20 s to about 5 min, most preferably from about 30 s to about 3 min.

[0098] Typically, all steps (a) to (d) may be used at any temperature from about 10 to about 40° C. If the temperature is higher, the compositions are not stable since the amount of ammonia will be quickly reduced by evaporation. A lower temperature is generally possible but would require intensive cooling. It is preferred that the temperature is from 10 to 35° C., even more preferred from 15 to 30° C.

[0099] In the fourth step (e) of the method the non-aqueous solution is removed from the contact with the substrate. Any known methods customarily used for removing liquids from solid surfaces can be employed. In a preferred embodiment this is done by [0100] (i) bringing the substrate into contact with a polar protic solvent, preferably a C.sub.1 to C.sub.4 alkanol, most preferably with 2-propanol, methanol or ethanol; and [0101] (ii) evaporating the polar protic solvent of step (i), preferably in the presence of an inert gas.

[0102] Preferably the inert gas is nitrogen.

[0103] All percent, ppm or comparable values refer to the weight with respect to the total weight of the respective composition except where otherwise indicated. All cited documents are incorporated herein by reference.

EXAMPLES

[0104] Patterned silicon wafers with a circular nano pillar pattern were used to determine the pattern collapse performance of the formulations during drying. The (aspect ratio) AR 20 pillars used for testing have a height of 600 nm and a diameter of 30 nm. The pitch size is 90 nm. 1 ×1 cm wafer pieces where processed in the following sequence without drying in between:

[0105] Process sequence without drying in between: [0106] 40 sec SC1 dip (NH.sub.4OH (28%) / H.sub.2O.sub.2 (31%) / ultra pure water (UPW) in a weight ratio of 1/8/60) [0107] 60 s ultra-pure water (UPW) dip, [0108] 30 s isopropanol (IPA) dip, [0109] 60 s dip of a solution of the siloxane additive in the non-polar organic solvent at room temperature, [0110] 60 s IPA dip, [0111] N2 blow dry.

[0112] The water content of the solvent was below 0.01% by weight.

[0113] The dried silicon wafers where analyzed with top down SEM and the collapse rates for examples 1.1 to 1.14 are shown in table 1.

TABLE-US-00001 Example Additive Conc. [wt %] Solvent Conc. [wt %] Stiffness [mN/m] Uncollapsed rate [%] C 1.1 n/a 0 isopropanol 100 44 0.4 C 1.2 triethoxysilane 5 isopropanol 95 43 0.8 C 1.3 n/a 0 n-heptane 100 43 1 1.4 triethoxysilane 0.2 n-heptane 99.8 43 5.9 1.5 triethoxysilane 2.5 n-heptane 97.5 42.5 9.2 1.6 triethoxysilane 5 n-heptane 95 43 61.3 1.7 triethoxysilane 10 n-heptane 90 42.5 48.7 1.8 triethoxysilane 20 n-heptane 80 42.5 36.8 C 1.9 n/a 0 n-decane 100 43 1.6 1.10 triethoxysilane 2.5 n-decane 97.5 42 40.5 1.11 triethoxysilane 5 n-decane 95 42.5 63.3 1.12 triethoxysilane 10 n-decane 90 42 45.3 C 1.13 n/a 0 p-xylene 100 43 1.7 1.14 triethoxysilane 5 p-xylene 95 42 43.1 C 1.15 n/a 0 n-heptane 100 77 4.3 1.16 triethoxysilane 5 n-heptane 95 77 77.7 C 1.17 triethoxysilane 4 PGMEA*** 96 43 0.6 C 1.18 triethoxylsilane 5 n-heptane* 94 45 n/a** * 1 wt% of trifluoromethanesulfonic acid was added to the composition ** The composition became turbid. *** PGMEA = propylene glycol methyl ether acetate

[0114] Table 1 shows that the additives in combination with the non-polar solvents have an extraordinary effect on the degree of pattern collapse compared to the solution without any additive or with a polar protic solvent in case of an alkaline SC1 pretreatment. C1.17 shows that the non-polar solvents according to the invention lead to much higher non-collapse rates in contrast to other non-protic but more polar solvents according to the prior art. C1.18 shows that the nonpolar solvents cannot be used in combination with an acid. In this case the additive was not fully soluble in the nonpolar solvent. This makes them unusable.

[0115] It is important to note that, due to the different pre-treatment and history of the respective wafers that were used, it is only possible to compare the results under comparable conditions, particularly the same stiffness.