COMPOSITION COMPRISING AN AMMONIA-ACTIVATED SILOXANE 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 protic solvent, (b) ammonia, and (c) at least one additive of formulae I or II

##STR00001## where R.sup.1 is H R.sup.2 is 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, R.sup.3 is selected from R.sup.2, R.sup.4 is 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, R.sup.10, R.sup.12 are independently selected from 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.

Claims

1. A non-aqueous composition comprising (a) an organic protic solvent (b) ammonia, and (c) at least one additive of formulae I or II ##STR00005## 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 protic solvent is a linear or branched C.sub.1 to C.sub.10 alkanol.

3. The composition according to claim 2, wherein the concentration of ammonia is from 0.1 to about 8% by weight.

4. The composition according to claim 1, further comprising a second solvent selected from the group consisting of linear, branched and cyclic C.sub.5 to C.sub.12 alkanes.

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

6. The composition according to claim 1, wherein the non-aqueous composition consists essentially of the organic protic solvent, optionally a C.sub.5 to C.sub.12 alkane, the at least one additive of formula I or II, ammonia, and reaction products thereof.

7. The composition according to claim 1, wherein the at least one additive of formula I or II is present in a concentration from 0.005 to 12% by weight.

8. 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.

9. 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.

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

11. A kit comprising (a) ammonia dissolved in an organic protic solvent, and (b) at least one additive of formulae I ##STR00006## 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.

12. 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 or equal 4, or a combination thereof.

13. A method for manufacturing integrated circuit devices, optical devices, micromachines and mechanical precision devices, the said method comprising the steps of (1) 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, (2) contacting the substrate at least once with a composition according to claim 1, and (3) removing the non-aqueous composition from the contact with the substrate.

14. The method according to claim 13, wherein the patterned material layers have line-space dimensions of 32 nm or less and aspect ratios of 10 or more.

15. The method according to claim 13, wherein the patterned material layers are selected from the group consisting of patterned developed photoresist layers, patterned barrier material layers, patterned multi-stack material layers and pattern dielectric material layers.

16. The composition according to claim 1, wherein the organic protic solvent is isopropanol.

17. The composition according to claim 2, wherein the concentration of ammonia is from 0.5 to about 2% by weight.

18. The composition according to claim 1, further comprising a second solvent selected from the group consisting of hexane, heptane, and octane.

19. The composition according to claim 1, wherein the at least one additive of formula I or II is present in a concentration from 0.05 to 10% by weight.

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

Description

DETAILED DESCRIPTION OF THE INVENTION

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] By way of example, the patterned material layers may be [0040] (a) patterned silicon oxide or silicon nitride coated Si layers, [0041] (b) patterned barrier material layers containing or consisting of ruthenium, cobalt, titanium nitride, tantalum or tantalum nitride, [0042] (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 [0043] d) patterned dielectric material layers containing or consisting of silicon dioxide or low-k or ultra-low-k dielectric materials.

[0044] Solvent

[0045] The non-aqueous anti-pattern-collapse composition comprises a polar protic organic solvent. Due to their hydrophilicity organic protic solvents are usually hygroscopicity and have a rather high amount of residual water unless removed by drying. Therefore, the organic protic solvents are preferably dried before its use in the anti-pattern-collapse compositions.

[0046] 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.

[0047] 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.

[0048] In a preferred embodiment the solvent essentially consists of one or more organic protic solvents, preferably a single polar protic organic solvent.

[0049] In another preferred embodiment the solvent essentially consists of one or more organic protic solvents and one or more non-polar C.sub.5 to C.sub.12 alkane solvents. Preferred are one or more alkane solvents, most preferred a single alkane solvent.

[0050] As used herein a “polar protic organic solvent” is an organic solvent which comprises an acidic hydrogen (i.e. that can donate a hydrogen ion).

[0051] Typical polar protic organic solvents are, without limitation, (a) C.sub.1 to C.sub.10 alcohols, (b) primary or secondary amines, carboxylic acids, such as but not limited to formic acid or acetic acid, or (c) primary or secondary amides, such as but not limited to formamide.

[0052] Preferred protic organic solvents are linear, branched or cyclic C.sub.1 to C.sub.10 aliphatic alkanols, particularly linear or branched C.sub.1 to C.sub.6 alkanols, which comprise at least one hydroxy group. Preferred alkanols are methanol, ethanol, 1-propanol, 2-propanol (isopropanol) or butanols. The most preferred alkanol is isopropanol.

[0053] Preferred C.sub.5 to C.sub.12 alkane solvents are selected from linear, branced or cyclic hexane, heptane, octane, nonane, and decane. Particularly preferred C.sub.5 to C.sub.12 alkane solvents are selected from linear or branched hexane, heptane, or octane. The most preferred C.sub.5 to C.sub.12 alkane solvent is linear or branched heptane, particularly linear heptane.

[0054] Additives of Formula I or II

[0055] 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:

##STR00003##

[0056] 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.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] In a particular preferred embodiment the additive is selected from trimethoxysilane, triethoxysilane, trimethylsilane, and triethylsilane.

[0064] 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.

[0065] There may be one or more additives in the composition, however it is preferred to use only one additive of formula I or II.

[0066] Ammonia Activation

[0067] It is required to activate the H-silane additive described above by adding ammonia. 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.

[0068] 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/NH.sub.4OH, Na.sub.2CO.sub.3/NaHCO.sub.3, tris-hydroxymethyl-aminomethane/HCl, 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, or [0072] (III) dispersants to prevent the surface re-attachment of the removed particles of dirt or polymer.

[0073] Rinsing Solution

[0074] Preferably the non-aqueous composition consists essentially of the organic protic solvent, optionally a C.sub.5 to C.sub.12 alkane, the at least one additive of formula I or II, ammonia, and reaction products thereof.

[0075] Preferably the ammonia is 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.

[0076] Application

[0077] 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.

[0078] The compositions described herein may be used in a method for manufacturing integrated circuit devices, optical devices, micromachines and mechanical precision devices has been found, the method comprising the steps of [0079] (1) providing a substrate having patterned material layers having line-space dimensions of 50 nm and less and aspect ratios of greater or equal 4, [0080] (2) contacting the substrate at least once with a non-aqueous, solution containing at least a siloxane additive as described herein, and [0081] (3) removing the aqueous solution from the contact with the substrate.

[0082] Preferably the substrate is provided by a photolithographic process comprising the steps of [0083] (i) providing the substrate with an immersion photoresist, EUV photoresist or eBeam photoresist layer, [0084] (ii) exposing the photoresist layer to actinic radiation through a mask with or without an immersion liquid, [0085] (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 10 or more, [0086] (iv) applying the non-aqueous composition described herein to the developed patterned photoresist layer, and [0087] (v) spin drying the semiconductor substrate after the application of the non-aqueous composition.

[0088] 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.

[0089] 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.

[0090] In case of immersion lithography preferably, ultra-pure water is used as the immersion liquid.

[0091] 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.

[0092] Preferably, the chemical rinse solutions are applied to the exposed and developed photoresist layers as puddles.

[0093] In the third step 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.

[0094] It is essential for photolithographic process according to the method of the invention, that the chemical rinse solution contains at least one of the siloxane additives.

[0095] 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.

EXAMPLES

Example 1

[0096] 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: [0097] 50 s Dilute Hydrofluoric Acid (DHF) 0.9% dip, [0098] 60 s ultra-pure water (UPVV) dip, [0099] 60 s isopropanol (IPA) dip, [0100] 60 s dip of a solution of the respective ammonia-activated additive in the solvent, either a protic organic solvent or a mixture of a protic and a non-polar organic solvent, at room temperature, [0101] 60 s IPA dip, [0102] N.sub.2 blow dry.

[0103] The additives were activated in-situ by adding the respective additives to a solution of 1% by weight of ammonia in the solvent. The water content of the solvent was below 0,01% by weight.

[0104] The compositions of table 1.1 were used in the examples.

TABLE-US-00001 TABLE 1 Conc. NH.sub.3 Protic Conc. Non-polar Conc. Example Additive [wt %] [wt %] Solvent [wt %] Solvent [wt %] Comp. 1.1 n/a 0 0 isopropanol 100 n/a 0 1.2 triethoxysilane 0.2 1 isopropanol 98.8 n/a 0 1.3 triethoxysilane 0.2 1 isopropanol 48.8 heptane 50 1.4 triethoxysilane 1 1 isopropanol 98 n/a 0 1.5 triethoxysilane 1 1 isopropanol 48 heptane 50 1.6 triethoxysilane 5 1 isopropanol 94 n/a 0 1.7 triethoxysilane 5 1 isopropanol 44 n/a 50 1.8 triethoxysilane 10 1 isopropanol 89 n/a 0 1.9 triethoxysilane 10 1 isopropanol 39 heptane 50

[0105] The dried silicon wafers where analyzed with top down SEM and the collapse statistics for examples 1.1 to 1.9 are shown in table 1.2.

[0106] The cluster size corresponds to number of uncollapsed pillars the respective cluster consist of. By way of example, if the wafer before treatment comprises 4×4 pillars and 8 remain uncollapsed, 4 collapse into two clusters comprising 2 pillars and 4 pillars collapse into one cluster comprising 4 pillars the ratio would be 8/11 single clusters, 2/11 double clusters and 1/11 clusters with four pillars.

TABLE-US-00002 TABLE 1.2 Uncollapsed Example structures [%] Comp. 1.1 24.35 1.2 54.35 1.3 59.15 1.4 55.85 1.5 62.75 1.6 55.95 1.7 64.25 1.8 69.55 1.9 72.45

[0107] Table 1.2 shows that additives 1.1 to 1.9 have a beneficial effect on the degree of pattern collapse compared to the solution without any additive. The addition of an alkane further increases the ratio of uncollapsed structures.

Example 2

[0108] 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: [0109] 40 sec SC1 dip (NH.sub.4OH (28%)/H.sub.2O.sub.2 (31%)/ultra pure water (UPA) in a weight ratio of 1/8/60) [0110] 60 s ultra-pure water (UPVV) dip, [0111] 60 s isopropanol (IPA) dip, [0112] 60 s dip of a solution of the respective ammonia-activated additive in the solvent, either a protic organic solvent or a mixture of a protic and a non-polar organic solvent, at room temperature, [0113] 60 s IPA dip, [0114] N.sub.2 blow dry.

[0115] The additives were activated in-situ by adding the respective additives to a solution of 1% by weight of ammonia in the solvent. The water content of the solvent was below 0,01% by weight.

[0116] The compositions of table 2.1 were used in the examples.

TABLE-US-00003 TABLE 2.1 Conc. NH.sub.3 Protic Conc. Non-polar Conc. Example Additive [wt %] [wt %] Solvent [wt %] Solvent [wt %] Comp. 2.1 n/a 0 0 isopropanol 100 n/a 0 22 triethoxysilane 0.2 1 isopropanol 98.8 n/a 0 23 triethoxysilane 0.2 1 isopropanol 48.8 heptane 50 24 triethoxysilane 1 1 isopropanol 98 n/a 0 2.5 triethoxysilane 1 1 isopropanol 48 heptane 50 2.6 triethoxysilane 5 1 isopropanol 94 n/a 0 2.7 triethoxysilane 5 1 isopropanol 44 n/a 50 2.8 triethoxysilane 10 1 isopropanol 89 n/a 0 2.9 triethoxysilane 10 1 isopropanol 39 heptane 50

[0117] The dried silicon wafers where analyzed with top down SEM and the amount of uncollapsed structures for examples 2.1 to 2.9 are shown in table 2.2.

TABLE-US-00004 TABLE 2.2 Uncollapsed Example structures [%] Comp. 2.1 0.35 2.2 22.15 2.3 59.3 2.4 50.7 2.5 70.1 2.6 82.25 2.7 88.7 2.8 89.65 2.9 92.7

[0118] The dried silicon wafers where analyzed with top down SEM.

[0119] Table 2.2 shows that the additives have a beneficial effect on the degree of pattern collapse compared to the solution without any additive.

Example 3

[0120] 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: [0121] 50 s Dilute Hydrofluoric Acid (DHF) 0.9% dip, [0122] 60 s ultra-pure water (UPVV) dip, [0123] 60 s isopropanol (IPA) dip, [0124] 60 s dip of a solution of the respective ammonia-activated additive in the solvent, either a protic organic solvent or a mixture of a protic and a non-polar organic solvent, at room temperature, [0125] 60 s IPA dip, [0126] N.sub.2 blow dry.

[0127] The additives were activated in-situ by adding the respective additives to a solution of 1% by weight of ammonia in the solvent. The water content of the solvent was below 0,01% by weight.

[0128] The dried silicon wafers where analyzed with top down SEM and the collapse statistics for examples 3.1 to 3.4 are shown in table 1.

[0129] The compositions of table 3.1 were used in the examples.

TABLE-US-00005 TABLE 3.1 Conc. NH.sub.3 Protic Conc. Non-polar Conc. Example Additive [wt %] [wt %] Solvent [wt %] Solvent [wt %] Comp. 3.1 n/a 0 0 isopropanol 100 n/a 0 3.2 1 0.2 1 isopropanol 98.8 n/a 0 3.3 2 0.2 1 isopropanol 98.8 n/a 0 3.4 3 0.2 1 isopropanol 98.8 n/a 0

[0130] Additives 1, 2 and 3 have the following structures:

##STR00004##

[0131] The dried silicon wafers where analyzed with top down SEM.

[0132] The pattern collapse Cluster Size Distribution was determined from the SEM images.

TABLE-US-00006 TABLE 3.2 Cluster Size Distribution in collapsed structures [%] Example 1 2 3-4 > 5 Comp. 3.1 49.9 35.3 14.6 0.2 3.2 59.6 27.2 12.6 0.6 3.3 77.6 18.2 4.1 0.2 3.4 75.8 17.1 6.7 0.4

[0133] Table 3.2 shows that additives have a beneficial effect on the degree of pattern collapse compared to the solution without any additive.

Comparative Example 4

[0134] 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: [0135] 50 s Dilute Hydrofluoric Acid (DHF) 0.9% dip, [0136] 60 s ultra-pure water (UPVV) dip, [0137] 60 s isopropanol (IPA) dip, [0138] 60 s dip of a solution of the respective ammonia-activated additive in the solvent, either a protic organic solvent or a mixture of a protic and a non-polar organic solvent, at room temperature, [0139] 60 s IPA dip, [0140] N.sub.2 blow dry.

[0141] The additives were activated in-situ by adding the respective additives to a solution of 1% by weight of ammonia in the solvent. The water content of the solvent was below 0,01% by weight.

[0142] The compositions of table 4.1 were used in the examples.

TABLE-US-00007 TABLE 4.1 Conc. NH.sub.3 Protic Conc. Non-polar Conc. Example Additive [wt %] [wt %] Solvent [wt %] Solvent [wt %] Comp. 4.1 — 0 0 isopropanol 100 n/a 0 Comp 4.2 TEOS 0.2 0 isopropanol 99.8 n/a 0 Comp 4.3 TEOS 0.2 1 isopropanol 98.8 n/a 0

[0143] The dried silicon wafers where analyzed with top down SEM.

[0144] The pattern collapse Cluster Size Distribution was determined from the SEM images. The cluster size corresponds to number of uncollapsed pillars the respective cluster consist of. By way of example, if the wafer before treatment comprises 4×4 pillars and 8 remain uncollapsed, 4 collapse into two clusters comprising 2 pillars and 4 pillars collapse into one cluster comprising 4 pillars the ratio would be 8/11 single clusters, 2/11 double clusters and 1/11 clusters with four pillars.

[0145] The collapse statistics for examples 4.1 to 4.3 are shown in table 4.2.

TABLE-US-00008 TABLE 4.2 Cluster Size Distribution in collapsed structures [%] Example 1 2 3-4 >5 1 81.4 16.8 1.8 0 2 19.5 3.7 76.2 0.6 3 80.8 17.1 2.1 0.1

[0146] Table 4.2 shows that non-H siloxanes like TEOS have no or less beneficial effect on the degree of pattern collapse compared to the solution without H siloxanes.

[0147] 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 within one example, it is, however, not possible to compare results from different examples.