Composition of combined arc and si-based hard mask thin films

Abstract

The new compositions comprise siloxane copolymers of anti-reflective coating (ARC) and hard mask (HM) compositions formed from the co-hydrolysis of the following monomers: (RO)4Si, R 1 SiCl3, R 2 SiCl3, R 3 SiCl3, and R 4 SiCl3wherein: R is an alkyl group such as a methyl or ethyl group, R 1 is a chromophore such as a phenyl, phenylmethyl, phenylethyl, and phenylpropyl group, R 2 is H, R 3 is a methyl or optionally substituted C2-C5 alkyl group, and optional R 4 is a hydrophilic group such as 2-[methoxy(polyethyleneoxy) 6‑9 propyl] or 2-(methoxycarbonyl)ethyl, wherein the molar % concentration of each monomer in the starting monomer mixture is 0.00 < (A), (B), (C), (D) < 0.95, 0.00 ≤ (E) < 0.50, and the total moles of (A) + (B) + (C) + (D) + (E) = 1.

Description

TECHNICAL FIELD

[0001] The present invention relates to an etch resistant anti-reflective composition, a method of coating a microelectronic device by using such a composition. BACKGROUND

[0002] Typical four layer photolithography:

[0003] • 1 - Organic photoresist (spin-on)

[0004] • 2 - Anti-reflective coating (ARC) (spin-on)

[0005] • 3 - Si containing hard mask (for etch selectivity, e.g. SiON) (chemical vapor deposition)

[0006] • 4 - C containing hard mask (amorphous carbon post-ACL) (chemical vapor deposition)

[0007] • 5 - Device wafer

[0008] Replacing layers 2 and 3 with one spin-on Si hard mask ARC results in a cost reduction.

[0009] To reduce the cost and improve performance of electronic devices, the semiconductor industry needs to have finer features to produce smaller but denser devices. To be able to manufacture smaller devices, new and better photolithography materials and methods are needed.

[0010] Typically, to pattern a semiconductor device, a single layer of photoresist (PR) is used on a substrate and an anti-reflective coating (ARC) to control light reflection from the underlying layer that can affect line edge roughness (LER) and critical dimension (CD).

[0011] Prior art such as Brewer Science's U.S. Patent No. 4,010,122 and U.S. Patent No. 5,693,691 teach the use of ARC in photolithography patterning.

[0012] As the resolution of photolithography patterning is increased, the need to reduce PR thickness has become an effective method to lower the aspect ratio of the PR / ARC stack and avoid pattern collapse.

[0013] However, the etch resistance of the organic PR in thinner PR / ARC stacks (Tokyo Electron Limited U.S. Patent No. 7,888,267) is not sufficient to transfer the pattern to the underlying layer, therefore, a new approach using a hard mask (HM) layer is used.

[0014] For example, Honeywell US Patent No. 6,506,497, Taiwan Semiconductor Manufacturing Company US Patent No. 6,777,340, Texas Instruments US Patent No. 6,803,661 teach the use of hard masks in a photolithography stack of PR / ARC / HM with better etch selectivity to transfer the pattern to the underlying layer.

[0015] PR stripping along with reactive ion etching (RIE) is used to transfer the pattern to the underlying layer as shown in the teachings of the following prior art: Novellus US Patent No. 8,178,443, US Patent No. 8,569,179, US Patent No. 8,664,124, US Patent No. 8,846,525, and Tokyo Electron Limited US Patent No. 9,576,816, US Patent No. 9,530,667, US Patent No. 9,607,843.

[0016] In a more efficient way, ARC and hard mask are combined into one layer, taught in the following patent specifications: IBM US Patent No. 6,420,088, IBM US Patent No. 7,077,903, IBM US Patent No. 7,276,327, Dow Corning US Patent No. 7,756,384, Tokyo Electron Limited US Patent No. 7,888,267, Brewer Science's US Patent No. 7,939,244, Samsung Industries US Patent No. 8,026,035, Global Foundries US Patent No. 8,492,279.

[0017] Therefore, there is always a welcome improvement in ARC / hard mask materials as a single layer to address the many integration issues that arise during semiconductor device manufacturing. SUMMARY

[0018] It is an object of the present invention to provide an etch resistant anti-reflective composition for ARC / HM comprising or consisting of:

[0019] a siloxane copolymer prepared from the co-hydrolysis of a mixture of chlorosilanes and alkoxysilanes, preferably in a one pot process, and in particular, the siloxane copolymer is formed from the co-hydrolysis of the following monomers in a solvent:

[0020] (A) (RO)4Si,

[0021] (B) R 1 SiCl3,

[0022] (C) R 2 SiCl3,

[0023] (D) R 3 SiCl3,

[0024] (E) R 4 SiCl3,

[0025] wherein:

[0026] R, at each occurrence, independently, represents an alkyl group having 1 to 12, preferably 1 to 8, more preferably 1 to 6 C atoms, most preferably methyl or ethyl,

[0027] R 1 at each occurrence, independently, represents an antireflection chromophore in the wavelength range of 180 to 210 nm, preferably 190 to 200 nm, more preferably 193 nm, for example phenyl, phenylmethyl, phenylethyl or phenylpropyl, in a microlithography, preferably an ArF microlithography at a wavelength of 193 nm,

[0028] R 2 is H,

[0029] R 3 at each occurrence, independently, represents methyl or an optionally substituted C2-C5 alkyl group,

[0030] R 4 at each occurrence, independently, represents a hydrophilic group, for example 2-[methoxy(polyethyleneoxy) 6-9 propyl] or 2-(carbomethoxy)ethyl,

[0031] wherein the molar % (mol %) concentration of each monomer in the starting monomer mixture is 0.00 < (A), (B), (C), (D) < 95 %, 0.00 < (E) < 50 %, wherein the preferred mol % range for (A) is 1 % < (A) < 50 %, the preferred mol % range for (B) is 8 % < (B) < 20 %, the preferred mol % range for (C) is 1 % < (C) < 50 %, the preferred mol % range for (D) is 1 % < (D) < 90 %, the preferred mol % range for (E) is 2 % < (E) < 20 %, and the total moles of (A) + (B) + (C) + (D) + (E) = 100 %.

[0032] The etch-resistant antireflection composition according to the present application, the monolayer thermally cured coating obtained thereby has very low reflectivity in ArF exposure and acts as an antireflective coating (ARC) in microlithography in the manufacturing process of semiconductor devices.

[0033] The etch resistant anti-reflective composition according to the present invention, the single layer thermally cured coating thus obtained is insoluble in photoresist solvents or developers.

[0034] The etch resistant anti-reflective composition according to the present invention, the single layer thermally cured coating thus obtained is converted into a hard mask (HM) with good etch selectivity during photolithography and etching processes.

[0035] Furthermore, the combination of the anti-reflective coating (ARC) and hard mask (HM) performance with the available entities is referred to as ARC / HM in the present invention.

[0036] According to a particular aspect of the present invention, the composition of the ARC / HM layer material is based on a siloxane copolymer containing Q structure (e.g. (Si-O)4linkage with four Si-O bonds) in the main chain to obtain stability and faster low temperature curing. Tetraalkoxysilane produces Q structure (e.g. (Si-O)4linkage with four Si-O bonds) and the tetrafunctional Q structure provides cross-linking action in the structure thus enhancing the structural stability.

[0037] According to a particular aspect of the present invention, the composition of the ARC / HM layer material has specific chromophore pendant groups on the siloxane main chain of the siloxane copolymer to tune the anti-reflective performance of the coating.

[0038] According to a particular aspect of the present invention, the composition of the ARC / HM layer material has specific Si mole percentage (%Si) on the siloxane main chain of the siloxane copolymer to tune the etch selectivity performance of the coating. The Si containing copolymer of the present invention improves etch resistance and improves etch selectivity to organic photoresists.

[0039] In a preferred embodiment, the composition according to the present invention has the following siloxane copolymer structure:

[0040] [R 1 Si(OH)2O 0.5 ]f[R 1 SiO 1.5 ]g[R 1 Si(OH)O]h[R 2 Si(OH)2O 0.5 ]m[R 2 SiO 1.5 ]n[R 2 Si(OH)O]p[Si(OH)3O 0.5 ]r[Si(OH)2O]s[Si(OH)O 1.5 ]t[SiO2]q[R 3 Si(OH)2O 0.5 ]v[R 3 SiO 1.5 ]w[R3 Si(OH)O]d[R 4 Si(OH)2O 0.5 x[R 4 SiO 1.5 y[R 4 Si(OH)O]z

[0041] where 0 < f, g, h, m, n, p, r, s, t, q, v, w, d < 0.9, 0.00 ≤ x, y, z < 0.50 and f + g + h + m + n + p + r + s + t + q + v + w + d + x + y + z = 1

[0042] R 1 is a chromophore such as phenyl, phenylmethyl, phenylethyl or phenylpropyl for antireflection in 193 nm photolithography

[0043] R 2 is H for increasing %Si for better etch selectivity

[0044] R 3 is methyl or an optionally substituted C2 - C5 alkyl group for stability

[0045] R 4 is a hydrophilic group such as 2 - [methoxy(polyethyleneoxy) 6-9 propyl] or 2 - (methoxycarbonyl)ethyl for adhesion

[0046] The etch - resistant antireflective composition according to the present invention, the siloxane copolymer helps to control the etch selectivity of the ARC / HM coating material by controlling the %Si of the siloxane copolymer in the composition. The %Si of the siloxane copolymer in the composition is controlled by the amount of the H - containing trichloro - or trialkoxy - silane component, that is, increasing the Si - H - containing component. Eventually, the higher the %Si of the etch - resistant antireflective coating, the better the etch resistance.

[0047] In the etch - resistant antireflective composition according to the present invention, the presence of Q units (e.g., a (Si - O - )4 linking group having four Si - O bonds) in the structure of the siloxane copolymer enhances thermal curing by introducing cross - link density into the siloxane polymer and increasing the silanol (Si - OH) functionality that is prone to cross - link in this structure. Tetraalkoxysilane generates a Q structure (e.g., a (Si - O)4 linking group having four Si - O bonds) in the main chain to obtain stability.

[0048] The number of Q units is controlled by controlling the amount of the combination of tetramethoxysilane or tetraethoxysilane or a mixture thereof.

[0049] According to the etch resistant anti-reflective composition of the present invention, silanol (Si-OH) functionality is also formed from T structures (e.g. R(Si-O-)3, RSi(OH)20 0.5 , RSiO 1.5 , RSi(OH)O, where R is a methyl or ethyl group) in the main chain siloxane copolymer, which is derived from alkyl or aryl containing trichlorosilane or trialkoxysilane. Uncondensed silanol functionality causes crosslinking of the coating at lower temperatures. T structures are formed from alkyl or aryl containing trichloro or trialkoxysilane.

[0050] It is another object of the present invention to provide a method of coating a microelectronic device comprising the steps of:

[0051] i. preparing an etch resistant anti-reflective composition according to the present invention,

[0052] ii. preparing an ARC / HM formulation by dissolving the etch resistant anti-reflective composition in a polar organic solvent;

[0053] iii. coating the formulation on a substrate to form a coating,

[0054] iv. evaporating the polar organic solvent from the coating,

[0055] v. curing the coating to form a thin film.

[0056] In an aspect of the method, in step (ii), the polar organic solvent is selected from ketones such as methyl isobutyl ketone (MIBK), methyl ethyl ketone (MEK), and cyclohexanone; alcohols such as methanol, ethanol, propanol, and isopropanol; ethers such as tetrahydrofuran (THF), ethylene glycol dimethyl ether, ethylene glycol diethyl ether, propylene glycol monomethyl ether (PGME), and dioxane; esters such as ethyl acetate, butyl acetate, ethyl lactate, and propylene glycol monomethyl ether acetate (PGMEA). The solvent in the total ARC / HM formulation of the coating solution can be in an amount of 90 wt% to 99 wt%.

[0057] In an aspect of the method, in step (v), the curing is performed at a temperature range of about 100°C to about 250°C.

[0058] In an aspect of the method, in step (v), the curing is performed in a time period of about 1 to about 2 minutes.

[0059] In an aspect of the method, the substrate is a Si wafer, a substrate of an integrated circuit, or other device substrate.

[0060] In an aspect of the method, wherein in step (iii), the coating is spin coating.

[0061] In an aspect of the method, the polar organic solvent is evaporated during the spin coating process.​

[0062] In one aspect of the method, the thickness of the thin film is from about 10 nm to about 200 nm.

[0063] It is another object of the present application to form a method of patterning a device comprising the steps of:

[0064] a. applying the etch resistant anti-reflective composition of the present application on a substrate of a device to form an etch resistant anti-reflective layer,

[0065] b. applying an ArF photoresist over the etch resistant anti-reflective layer,

[0066] c. photo patterning the ArF photoresist and forming a resist pattern over the etch resistant anti-reflective layer,

[0067] d. removing the exposed areas by etching and producing a patterned device.

[0068] To prepare the etch resistant anti-reflective composition of the present application, the solution containing the siloxane copolymer can be spin coated and thermally cured at a temperature of 100-250°C for a time period of 30-60 seconds to block solubility in photoresist solvents and developers. BRIEF DESCRIPTION OF DRAWINGS

[0069] Examples of applying the ARC / HM coating of the present application in semiconductor device manufacturing are illustrated in Figure 1 The photolithography, patterning and etching steps are illustrated in the following figures:

[0070] Figure 1 a illustrates a cross section of a coated stack of a mask (filled black area) on a substrate, (1) photoresist, (2) ARC / HM, (3) SiN or ACL, (4) dielectric layer, where the downward arrow shows ArF exposure;

[0071] Figure 1 b illustrates the patterned photoresist layer (1) exposed and developed on top of the other layers;

[0072] Figure 1 c illustrates the photoresist (1) pattern transfer to the ARC / HM (2) layer;

[0073] Figure 1 d illustrates the photoresist (1) layer removed from the stack, leaving the patterned ARC / HM (2);

[0074] Figure 1 e illustrates the pattern transfer of the ARC / HM (2) to the SiN or ACL (3) layer;

[0075] Figure 1 f illustrates the ARC / HM (2) removed from the stack, leaving the patterned SiN or ACL (3);

[0076] Figure 1 g illustrates the SiN or ACL (3) pattern transfer to the dielectric layer (4);

[0077] Figure 1 h illustrates the SiN or ACL (3) removed from the stack leaving the patterned dielectric layer (4).

[0078] In Figure 2 illustrates an example of a typical four layer lithography method, where

[0079] Figure 2 I illustrates a cross section of the stack of four coated layers on a substrate, mask (filled black area), (1) photoresist, (2) ARC, (3) hard mask, (4) SiN or ACL, (5) dielectric layer, where the downward arrow shows the ArF exposure;

[0080] Figure 2 J illustrates the patterned photoresist layer (1) exposed and developed on top of the other layers;

[0081] Figure 2 K illustrates the photoresist (1) pattern RIE transfer to the ARC (2) and hard mask layer (3);

[0082] Figure 2 L illustrates the C-hard mask etch (4);

[0083] Figure 2 M illustrates the pattern transfer to the underlying layer;

[0084] Figure 2 N illustrates the C-hard mask removed from the stack leaving the patterned IC (dielectric) layer.

[0085] DETAILED DESCRIPTION

[0086] The present invention provides an etch resistant anti-reflective composition, the heat cured coating obtained thereby has very low reflectivity in ArF exposure and acts as an anti-reflective coating (ARC) in the microlithography method of semiconductor device manufacturing processes.

[0087] The present invention provides an etch resistant anti-reflective composition, the heat cured coating obtained thereby is converted to a hard mask (HM) with good etch selectivity during the lithography and etching processes.

[0088] The present invention provides an etch resistant anti-reflective composition, the heat cured coating obtained thereby is insoluble in photoresist solvents or developers.

[0089] In an important aspect of the present application, a combination of both antireflective coating (ARC) and hardmask (HM) performance is achieved after curing the ARC / HM coating produced from the present etch resistant antireflective composition, comprising a siloxane copolymer formed by the cohydrolysis of the following monomers in a solvent:

[0090] (A) (RO)4Si,

[0091] (B) R 1 SiCl3,

[0092] (C) R 2 SiCl3,

[0093] (D) R 3 SiCl3,

[0094] (E) R 4 SiCl3,

[0095] wherein:

[0096] R, at each occurrence, independently, represents an alkyl group having 1 to 12, preferably 1 to 8, more preferably 1 to 6 C atoms, most preferably methyl or ethyl,

[0097] R 1 at each occurrence, independently, represents an antireflective chromophore in microlithography at a wavelength of 180 to 210 nm, preferably 190 to 200 nm, more preferably 193 nm, such as phenyl, phenylmethyl, phenylethyl or phenylpropyl, said microlithography preferably being ArF microlithography at a wavelength of 193 nm,

[0098] R 2 is H,

[0099] R 3 at each occurrence, independently, represents methyl or optionally substituted C2-C5 alkyl,

[0100] R 4 at each occurrence, independently, represents a hydrophilic group such as 2-[methoxy(polyethyleneoxy) 6-9 propyl] or 2-(methoxycarbonyl)ethyl,

[0101] wherein the concentration of each monomer in the starting monomer mixture in mole % (mol%) is 0.00 < (A), (B), (C), (D) < 95%, 0.00 < (E) < 50%, wherein the preferred mole % range for (A) is 1% < (A) < 50%, the preferred mole % range for (B) is 8% < (B) < 20%, the preferred mole % range for (C) is 1% < (C) < 50%, the preferred mole % range for (D) is 1% < (D) < 90%, the preferred mole % range for (E) is 2% < (E) < 20%, and the total moles of (A) + (B) + (C) + (D) + (E) = 100%.

[0102] Monomer (A) helps in Q structure in the main chain (e.g. (Si-O)4linkage with four Si-O bonds) in the siloxane copolymer which is used to get stability and faster low temperature cure. Tetraalkoxysilane gives Q structure (e.g. (Si-O)4linkage with four Si-O bonds).

[0103] Monomer (B) controls n and K values which optimizes the reflection of ArF exposure light and minimizes reflectivity.

[0104] Monomer (C) helps in better etch selectivity by increasing the % Si content of the siloxane copolymer.

[0105] Monomer (D) also increases the % Si content of the siloxane copolymer and better solubility of the material in organic solvents.

[0106] Monomer (E) for better solubility and adhesion.

[0107] In another important aspect of the present invention, the siloxane copolymer in the etch resistant antireflective composition of the present invention has the following structure:

[0108] [R 1 Si(OH)2O 0.5 ] f [R 1 SiO 1.5 ] g [R 1 Si(OH)O] h [R 2 Si(OH)2O 0.5 ] m [R 2 SiO 1.5 ] n [R 2 Si(OH)O] p [Si(OH)3O 0.5 ] r [Si(OH)2O] s [Si(OH)O 1.5 ]t [SiO2] q [R 3 Si(OH)2O 0.5 ] v [R 3 SiO 1.5 ] w [R 3 Si(OH)O] d [R 4 Si(OH)2O 0.5 ] x [R 4 SiO 1.5 ] y [R 4 Si(OH)O] z

[0109] where 0 < f, g, h, m, n, p, r, s, t, q, v, w, d < 0.9, 0.00 < x, y, z < 0.50 and f + g + h + m + n + p + r + s + t + q + v + w + d + x + y + z = 1

[0110] R is an alkyl group such as methyl or ethyl;

[0111] R 1 is a chromophore such as phenyl, phenylmethyl, phenylethyl and phenylpropyl for ARC performance in 193 nm microlithography;

[0112] R 2 is H for increasing % Si for better etch selectivity;

[0113] R 3 is methyl or optionally substituted C2-C5 alkyl group for stability;

[0114] R 4 is a hydrophilic group such as 2-[methoxy(polyethyleneoxy) 6-9 propyl] or 2-(methycarbomato)ethyl for adhesion.

[0115] The siloxane copolymer in the etch resistant anti-reflective composition of the present invention is prepared in a single synthetic process by the co-hydrolysis of a mixture of chlorosilane monomers and alkoxy silane monomers. The monomers can be selected from the group consisting of tetraalkoxysilane such as tetraethoxysilane or tetramethoxysilane or a combination of both. The monomers are also selected from the group consisting of aryl containing trichlorosilane such as phenyl trichlorosilane, or phenyl methyl trichlorosilane, or phenyl ethyl trichlorosilane, or phenyl propyl trichlorosilane, or a combination thereof. The monomers are also selected from the group consisting of H containing trichlorosilane or trialkoxysilane such as trichlorosilane, or trimethoxysilane, or triethoxysilane, or a combination thereof. The monomers are also selected from the group consisting of alkyl containing trichlorosilane or trialkoxysilane such as methyl trichlorosilane, or ethyl trichlorosilane, or propyl trichlorosilane, or butyl trichlorosilane, or pentyl trichlorosilane, or methyl trimethoxysilane, or ethyl trimethoxysilane, or propyl trimethoxysilane, or butyl trimethoxysilane, or methyl triethoxysilane, or ethyl triethoxysilane, or propyl triethoxysilane, or a combination thereof. The monomers are also selected from the group consisting of trichlorosilane or trialkoxysilane containing hydrophilic groups such as 2-[methoxy(polyethyleneoxy) 6-9 2-(methoxycarbonyl)ethyl trichlorosilane, or a combination thereof.

[0116] Useful chromophores that can be used as pendant groups of the trichlorosilane or trialkoxysilane can be selected from the group consisting of aryl containing moieties such as phenyl trichlorosilane, or phenyl methyl trichlorosilane, or phenyl ethyl trichlorosilane, or phenyl propyl trichlorosilane, or phenyl trimethoxysilane, or phenyl methyl trimethoxysilane, or phenyl methyl trimethoxysilane, or phenyl ethyl trimethoxysilane, or phenyl propyl trimethoxysilane, or phenyl triethoxysilane, or phenyl methyl triethoxysilane, or phenyl methyl triethoxysilane, or phenyl ethyl triethoxysilane, or phenyl propyl triethoxysilane. In addition, the values of the refractive index (n) and the extinction coefficient (k) of the light reflection of the ARC / HM coating can be adjusted and controlled by controlling the amount of silane containing the corresponding chromophore used in the synthesis of the siloxane copolymer.

[0117] In an important aspect of the present invention, the siloxane copolymer in the etch resistant anti-reflective composition of the present invention controls the etch selectivity of the ARC / HM coating material by controlling the % Si in the composition of the siloxane copolymer. The % Si of the siloxane copolymer in the composition is controlled by the amount of H containing trichlorosilane or trialkoxysilane and the other trichlorosilane or trialkoxysilane monomers. The mole percent of Si in the final copolymer (% Si) ranges from 8 mole % to 46 mole %, more preferably ranges from 15 mole % to 45 mole %, and most preferably ranges from 35 mole % to 45 mole %.

[0118] In yet another important aspect of the present application, the useful portion of the siloxane copolymer in the etch resistant anti-reflective composition of the present application includes Q units (e.g., (Si-0)4linkages having four Si-0 bonds) present in the structure that enhance thermal cure by introducing crosslinking density into the siloxane polymer as well as increasing silanol (Si-OH) functionality in the structure that is readily crosslinkable. Tetraalkoxysilane, tetramethoxysilane, or tetraethoxysilane creates Q structures (e.g., (Si-0)4linkages) in the backbone for stability and Si-OH for faster thermal cure.

[0119] The number of Q units is controlled by controlling the amount of tetraalkoxysilane, such as tetramethoxysilane or tetraethoxysilane, or mixtures thereof.

[0120] Silanol (Si-OH) functionality is also formed from T structures (e.g., RSi(OH)20 0.5 , RSiO 1.5 , RSi(OH)0, where R is selected from alkyl or aryl containing trichlorosilane or trialkoxysilane). Uncondensed silanol functionality causes crosslinking of the coating at lower temperatures.

[0121] T structures are formed from alkyl or aryl containing trichlorosilane or trialkoxysilane, such as methyltrichlorosilane, or ethyltrichlorosilane, or propyltrichlorosilane, or butyltrichlorosilane, or pentyltrichlorosilane, or methyltrimethoxysilane, or ethyltrimethoxysilane, or propyltrimethoxysilane, or butyltrimethoxysilane, or methyltriethoxysilane, or ethyltriethoxysilane, or propyltriethoxysilane, or phenyltrichlorosilane, or phenylmethyltrichlorosilane, or phenylethyltrichlorosilane, or phenylpropyltrichlorosilane, or phenyltrimethoxysilane, or phenylmethyltrimethoxysilane, or phenylethyltrimethoxysilane, or phenylpropyltrimethoxysilane, or phenyltriethoxysilane, or phenylmethyltriethoxysilane, or phenylethyltriethoxysilane, or phenylpropyltriethoxysilane.

[0122] The number of T structures is controlled by controlling the amount of methyltrichlorosilane, or ethyltrichlorosilane, or propyltrichlorosilane, or butyltrichlorosilane, or pentyltrichlorosilane, or methyltrimethoxysilane, or ethyltrimethoxysilane, or propyltrimethoxysilane, or butyltrimethoxysilane, or methyltriethoxysilane, or ethyltriethoxysilane, or propyltriethoxysilane, or phenyltrichlorosilane, or phenylmethyltrichlorosilane, or phenylethyltrichlorosilane, or phenylpropyltrichlorosilane, or phenyltrimethoxysilane, or phenylmethyltrimethoxysilane, or phenylethyltrimethoxysilane, or phenylpropyltrimethoxysilane, or phenyltriethoxysilane, or phenylmethyltriethoxysilane, or phenylethyltriethoxysilane, or phenylpropyltriethoxysilane.

[0123] The co-hydrolysis and condensation of the monomers of the present application can form siloxane copolymers in a network of random branching and cages of various structural sizes with mixtures of T and Q units.

[0124] Uncondensed silanol (Si-OH) functionality from both T and Q structures in the siloxane copolymers tends to crosslink and complete the formation of three and four Si-O-Si bonds around each silicon atom in the corresponding T and Q structures during thermal curing. The stability of the ARC / HM coating in organic solvents increases as the Si-OH condensation and the formation of Si-O-Si bonds increase, the more completely condensed the ARC / HM coating, the more stable the coating is in organic solvents. The thermally cured ARC / HM coating must be insoluble in photoresist solvents and developers to be stable during subsequent photoresist coating and development processes. Optionally, a thermal curing catalyst can be used as a formulation additive to increase the thermal curing speed of the ARC / HM coating. The amount of acid such as acetic acid, hydrochloric acid, sulfonic acid, methanesulfonic acid, or phosphoric acid is 100 to 1000 ppm. Alternatively, the condensation catalyst can be selected from thermal acid or thermal base generators. The amount of Si containing monomers with T and Q structures can control the %Si in the final composition.

[0125] The ARC / HM siloxane copolymers of the present application can have a weight average molecular weight (Mw) of about 800 to about 50,000 as determined by gel permeation chromatography (GPC). A more preferred range is about 1,000 to 30,000 and a most preferred range is about 1,500 to 20,000.

[0126] The solvent in the co-hydrolysis is a mixture of water and at least one other solvent selected from the following organic solvents: ketones such as methyl isobutyl ketone (MIBK), methyl ethyl ketone (MEK), or cyclohexanone; alcohols such as methanol, ethanol, propanol, or isopropanol; ethers such as tetrahydrofuran (THF), ethylene glycol dimethyl ether, ethylene glycol diethyl ether, propylene glycol monomethyl ether (PGME), or dioxane; esters such as ethyl acetate, butyl acetate, ethyl lactate, and propylene glycol monomethyl ether acetate (PGMEA). The amount of the organic solvent and the water in the mixture is 10 wt% - 95 wt% each. The solvent in the co-hydrolysis is a mixture of water and at least one other solvent selected from the following organic solvents: ketones such as methyl isobutyl ketone (MIBK), methyl ethyl ketone (MEK), or cyclohexanone; alcohols such as methanol, ethanol, propanol, or isopropanol; ethers such as tetrahydrofuran (THF), ethylene glycol dimethyl ether, ethylene glycol diethyl ether, propylene glycol monomethyl ether (PGME), or dioxane; esters such as ethyl acetate, butyl acetate, ethyl lactate, and propylene glycol monomethyl ether acetate (PGMEA). The amount of the organic solvent and the water in the mixture is 10 wt% - 95 wt% each.

[0127] In some embodiments, the siloxane copolymer can comprise 1 wt% to 10 wt% of the total ARC / HM formulation of the coating solution.

[0128] Spin coating can be used as a method of applying the ARC / HM formulation in semiconductor device fabrication. The method of spin coating typically entails pouring a small amount of the ARC / HM solution slurry onto the surface of the semiconductor device, followed by an acceleration of 4000-5000 rpm to a selected final speed of 2000 to 3000 rpm, which spreads the material over the surface and maintains the final speed for 10-20 seconds before completing the spin. This results in a uniform coating of the ARC / HM material as an ARC / HM layer on the surface of the semiconductor device.

[0129] The ARC / HM coating can be thermally cured by heating, for example, a hot plate or a heating oven, in semiconductor device fabrication by using any of the commonly suitable techniques used in curing. The ARC / HM coating can be thermally cured at a temperature of 100-250 °C for a time period of 30-60 seconds to increase the cross-linking density of the siloxane copolymer in the coating and condense the silanol (Si-OH) groups to form Si-O-Si bonds. The thermally cured siloxane copolymer will be sufficiently cured to be stable in photoresist solvents such as PGMEA, PGME, gamma butyrolactone (GBL), ethyl lactate (EL), and the like.

[0130] After applying and curing the ARC / HM coating, a thin photoresist layer is spin coated on the surface of the cured ARC / HM coating, followed by a photo patterning process of exposing and developing the photoresist to produce a patterned photoresist structure. The next step is to transfer the patterned photoresist pattern to the ARC / HM layer using reactive ion etching (RIE). The step after the pattern transfer through the ARC / HM layer is oxygen plasma etching to remove the photoresist and convert the patterned ARC / HM layer into a mostly patterned hard mask layer. This patterned hard mask will also be able to pattern transfer to the underlying layers by using suitable RIE etching chemicals, followed by removing the hard mask and producing the target patterned structure on the semiconductor device.

[0131] Figure 1 The example in the section describes the application of the ARC / HM coating of the present invention in semiconductor device fabrication, however, this is not the only use and is not intended to be a limiting factor on the use of the present invention, and the coating of the present invention can be used in many other ways. The geometries and dimensions used in this example are only for illustration to better clarify the example and are not representative of actual geometries and dimensions.

[0132] The substrate can be a conductive material or a semi-conductive material such as Si, Ge, Al, and the like, or an alloy such as SiGe, gallium arsenide, and the like, or an insulator such as SiO2, Si3N4, and the like, or their doped variants or mixtures. The example of the target layer to be patterned in this example is a dielectric (4) layer. Figure 1The layer (3) in the stack of a is SiN or an amorphous carbon layer (ACL). The ARC / HM silicon copolymer composition of the present application is spin-coated on the layer (3) at a speed of about 2000 to about 3000 rpm for a period of about 10 seconds to about 20 seconds. The ARC / HM silicon copolymer composition coating is then heat cured at a temperature of about 100 °C to about 250 °C for a period of about 30 seconds to about 60 seconds to increase the cross-linking density of the copolymer in the coating and condense the silanol (Si-OH) to form Si-O-Si bonds, which results in an ARC / HM layer (2) that is insoluble in photoresist solvent that is spin-coated in the subsequent step of photoresist coating. The ARC / HM layer (2) has light absorption properties that are controlled by adjusting the amount of chromophore in the composition and the thickness of the coating to optimize n and k to reduce reflection of light. To complete the stack of a, the photoresist is spin-coated and patterned by ArF light through an exposure mask (filled black area) and developed to remove the exposed areas. The stack of a-h is illustrated in more detail in the following figures in which the photoresist, ARC / HM, SiN or ACL, and dielectric layers are shown as cross-sections of the coated layers on the substrate. Figure 1 To complete the stack of a, the photoresist is spin-coated and patterned by ArF light through an exposure mask (filled black area) and developed to remove the exposed areas. The stack of a-h is illustrated in more detail in the following figures in which the photoresist, ARC / HM, SiN or ACL, and dielectric layers are shown as cross-sections of the coated layers on the substrate. Figure 1 The photoresist, ARC / HM, SiN or ACL, and dielectric layers are shown as cross-sections of the coated layers on the substrate.

[0133] Figure 1 a illustrates the cross-section of the coated layers of the stack of a mask (filled black area), (1) photoresist, (2) ARC / HM, (3) SiN or ACL, (4) dielectric layer on the substrate, where the downward arrow shows ArF exposure.

[0134] Figure 1 b illustrates the patterned photoresist layer (1) exposed and developed on top of the other layers.

[0135] Figure 1 c illustrates the photoresist (1) pattern transferred to the ARC / HM layer (2) when the ARC / HM layer (2) is patterned using the photoresist pattern as an etch mask.

[0136] Figure 1 d illustrates the photoresist layer (1) removed from the stack leaving the patterned ARC / HM layer (2) to be used as a hard mask for the underlying layer on other target materials.

[0137] Figure 1 e illustrates the ARC / HM layer (2) pattern transferred to the underlying SiN or ACL (3).

[0138] Figure 1 f illustrates the ARC / HM layer (2) removed from the stack leaving the patterned SiN or ACL (3) layer.

[0139] Figure 1 g illustrates the SiN or ACL (3) pattern transferred to the dielectric layer (4).

[0140] Figure 1 h illustrates the SiN or ACL (3) layer removed from the stack leaving the patterned dielectric target layer (4).

[0141] The present invention has the following advantages over the prior art:

[0142] The polymers in the prior art do not address the Q structure, but the present invention uses polymers with Q structure to obtain enhanced stability and faster curing from the Si-OH condensation formed from the incompletely condensed Si-OH produced during hydrolysis;

[0143] The etch resistant antireflective composition according to the present invention, the monolayer thermally cured coating obtained thereby

[0144] Having very low reflectivity in ArF exposure and acting as an antireflective coating (ARC) in microlithography in semiconductor device manufacturing processes;

[0145] Insoluble in photoresist solvents or developers;

[0146] Converts to a hard mask (HM) with good etch selectivity during lithography and etching processes;

[0147] Furthermore, the composition of the ARC / HM layer material is based on a siloxane copolymer containing a Q structure (e.g. a (Si-O)4linkage with four Si-O bonds) in the main chain to obtain stability and faster low temperature curing; the tetraalkoxysilane produces the Q structure (e.g. a (Si-O)4with four Si-O bonds) and the tetrafunctional Q structure provides crosslinking action in the structure, thus enhancing the structural stability; the composition of the ARC / HM layer material has specific chromophore pendant groups on the siloxane main chain of the siloxane copolymer to tune the antireflective properties of the coating;

[0148] Furthermore, the siloxane copolymer helps to control the etch selectivity of the ARC / HM coating material by controlling the %Si of the siloxane copolymer in the composition; the amount of H-containing trichloro- or trialkoxy-silane component controls the %Si of the siloxane copolymer in the composition, i.e. increasing the Si-H containing component, the higher the %Si of the final etch resistant antireflective coating, thus the better the etch resistance. The following synthetic examples to produce various compositions are presented to illustrate their synthesis and the results of the coatings. These examples should not be considered limiting. The general procedure for preparing the siloxane copolymer is based on the single pot co-hydrolysis of the following monomers: (RO)4Si, R 1 SiCl3, R 2 SiCl3, R 3 SiCl3and R 4 SiCl3, where: R is an ethyl group, R 1 is a phenyl group, R 2 is H, R3 is methyl, R 4 is 2-[methoxy(polyethyleneoxy) 6-9 propyl] or 2-(methoxycarbonyl)ethyl, wherein the molar % concentration of each monomer in the starting monomer mixture is 0.00 < (A), (B), (C), (D) < 95%, 0.00 < (E) < 50%, and the total moles of (A) + (B) + (C) + (D) + (E) = 1. DETAILED DESCRIPTION

[0149] EXAMPLE

[0150] Example 1

[0151] A 500 mL jacketed glass vessel was charged with a mixture of tetraethoxysilane (20 g, 0.1 moles), phenyltrichlorosilane (5.5 g, 0.03 moles), methyltrichlorosilane (12 g, 0.08 moles), trichlorosilane (9.0 g, 0.07 moles), and PGMEA (200 g). The mixture was stirred and cooled to 18 °C by controlling the jacket temperature using a recirculating chiller / heater system. A clear homogeneous mixture of water (11.0 g, 0.61 moles) and PGMEA (200 g) was added to the mixture in the 500 mL vessel over 60 minutes by a metering pump. After the water / PGMEA mixture addition was complete, the 500 mL vessel was heated to 35 °C and stirred for 4 hours. The resulting mixture was cooled to 20 °C, rinsed with water, and then rotary evaporated to remove trace amounts of water. The resulting product was characterized by GPC and finally formulated to 4% solids in PGMEA.

[0152] Example 2

[0153] A 500 mL jacketed glass vessel was charged with a mixture of tetraethoxysilane (20 g, 0.1 moles), phenyltrichlorosilane (5.5 g, 0.03 moles), methyltrichlorosilane (12 g, 0.08 moles), trichlorosilane (7.0 g, 0.05 moles), 2-[methoxy(polyethyleneoxy) 6-9 propyl]trichlorosilane (5.0 g, 0.01 moles), and PGMEA (200 g). The mixture was stirred and cooled to 18 °C by controlling the jacket temperature using a recirculating chiller / heater system. A clear homogeneous mixture of water (11.0 g, 0.61 moles) and PGMEA (200 g) was added to the mixture in the 500 mL vessel over 60 minutes by a metering pump. After the water / PGMEA mixture addition was complete, the 500 mL vessel was heated to 35 °C and stirred for 4 hours. The resulting mixture was cooled to 20 °C, rinsed with water, and then rotary evaporated to remove trace amounts of water. The resulting product was characterized by GPC and finally formulated to 4% solids in PGMEA.

[0154] Example 3

[0155] A 500 mL jacketed glass vessel was charged with tetraethoxysilane (20 g, 0.1 mole), phenyltrichlorosilane (5.5 g, 0.03 mole), methyltrichlorosilane (12 g, 0.08 mole), trichlorosilane (7.0 g, 0.05 mole), 2-[methoxy(polyethyleneoxy) 6-9 propyl]trimethoxysilane (5.0 g, 0.01 mole), and PGMEA (200 g). The mixture was stirred and cooled to 18 °C by controlling the jacket temperature using a recirculating chiller / heater system. A clear, homogeneous mixture of water (11.0 g, 0.61 mole) and PGMEA (200 g) was added to the mixture in the 500 mL vessel over 60 minutes by a metering pump. After the water / PGMEA mixture addition was complete, the 500 mL vessel was heated to 35 °C and stirred for 4 hours. The resulting mixture was cooled to 20 °C, rinsed with water, and rotary evaporated to remove trace amounts of water. The resulting product was characterized by GPC and finally formulated to 4% solids in PGMEA.

[0156] Example 4

[0157] A 500 mL jacketed glass vessel was charged with tetraethoxysilane (15 g, 0.07 mole), phenyltrichlorosilane (5.5 g, 0.03 mole), methyltrichlorosilane (16 g, 0.11 mole), trichlorosilane (7.5 g, 0.06 mole), 2-[methoxy(polyethyleneoxy) 6-9 propyl]trimethoxysilane (5.0 g, 0.01 mole), and PGMEA (200 g). The mixture was stirred and cooled to 18 °C by controlling the jacket temperature using a recirculating chiller / heater system. A clear, homogeneous mixture of water (11.0 g, 0.61 mole) and PGMEA (200 g) was added to the mixture in the 500 mL vessel over 60 minutes by a metering pump. After the water / PGMEA mixture addition was complete, the 500 mL vessel was heated to 35 °C and stirred for 4 hours. The resulting mixture was cooled to 20 °C, rinsed with water, and rotary evaporated to remove trace amounts of water. The resulting product was characterized by GPC and finally formulated to 4% solids in PGMEA.

[0158] Example 5

[0159] A 500 mL jacketed glass vessel was charged with tetraethoxysilane (10 g, 0.05 mole), phenyltrichlorosilane (5.5 g, 0.03 mole), methyltrichlorosilane (20 g, 0.13 mole), trichlorosilane (7.6 g, 0.06 mole), 2-[methoxy(polyethyleneoxy) 6-9A mixture of methyltrichlorosilane (25 g, 0.17 mole), phenyltrichlorosilane (6.0 g, 0.03 mole), and PGMEA (200 g). The mixture was stirred and cooled to 18 °C by controlling the jacket temperature using a recirculating chiller / heater system. A clear, homogeneous mixture of water (11.0 g, 0.61 mole) and PGMEA (200 g) was added to the mixture in the 500 mL vessel over 60 minutes by a metering pump. After the water / PGMEA mixture addition was complete, the 500 mL vessel was heated to 35 °C and stirred for 4 hours. The resulting mixture was cooled to 20 °C, rinsed with water, and rotary evaporated to remove trace amounts of water. The resulting product was characterized by GPC and finally formulated to 4% solids in PGMEA.

[0160] Example 6

[0161] A 500 mL jacketed glass vessel was charged with tetraethoxysilane (6.0 g, 0.03 mole), phenyltrichlorosilane (6.0 g, 0.03 mole), methyltrichlorosilane (25 g, 0.17 mole), trichlorosilane (8.0 g, 0.06 mole), 2-[methoxy(polyethyleneoxy) 6-9 A mixture of methyltrichlorosilane (25 g, 0.17 mole), phenyltrichlorosilane (6.0 g, 0.03 mole), and PGMEA (200 g). The mixture was stirred and cooled to 18 °C by controlling the jacket temperature using a recirculating chiller / heater system. A clear, homogeneous mixture of water (11.0 g, 0.61 mole) and PGMEA (200 g) was added to the mixture in the 500 mL vessel over 60 minutes by a metering pump. After the water / PGMEA mixture addition was complete, the 500 mL vessel was heated to 35 °C and stirred for 4 hours. The resulting mixture was cooled to 20 °C, rinsed with water, and rotary evaporated to remove trace amounts of water. The resulting product was characterized by GPC and finally formulated to 4% solids in PGMEA.

[0162] Example 7

[0163] A 500 mL jacketed glass vessel was charged with tetraethoxysilane (6.0 g, 0.03 mole), phenyltrichlorosilane (6.0 g, 0.03 mole), methyltrichlorosilane (25 g, 0.17 mole), trichlorosilane (8.0 g, 0.06 mole), 2-[methoxy(polyethyleneoxy) 6-9A mixture of trichloro(propyl)silane (5.0 g, 0.01 mole) and PGMEA (200 g). The mixture was stirred and cooled to 18°C by controlling the jacket temperature using a recirculating chiller / heater system. A clear, homogeneous mixture of water (12.0 g, 0.78 mole) and PGMEA (230 g) was added to the mixture in a 500 mL vessel over 60 minutes by a metering pump. After the water / PGMEA mixture addition was complete, the 500 mL vessel was heated to 35°C and stirred for 4 hours. The resulting mixture was cooled to 20°C, rinsed with water and rotary evaporated to remove trace amounts of water. The resulting product was characterized by GPC and finally formulated to 4% solids in PGMEA.

[0164] Characterization and Testing:

[0165] The silicone copolymers synthesized in the above examples were characterized by Waters GPC (gel permeation chromatography) using tetrahydrofuran as the carrier solvent. Column calibration was performed using polystyrene standards with molecular weights ranging from 500 to 50,000 Daltons. Table 1 summarizes the GPC results for the silicone copolymers of the above examples.

[0166] The silicone copolymers of the above examples were filtered using a 0.1 micron Teflon filter and spin coated on Si wafers using a Laurel spinner at an acceleration of 3,000-6,000 rpm and a final speed of 20-50 seconds hold time. The coated wafers were hot plate cured at 200-250°C for 30-60 seconds. The yield, Mw / Mn, n, and K of the cured films are summarized in Table 1.

[0167] Table 1

[0168]

[0169] The results of the peel tests for the cured films with PGMEA and TMAH were performed with 30 seconds of agitation for PGMEA and 60 seconds of agitation for TMAH. The film thickness was measured before and after the peel test using a Theta Metrisis model FR-Basic. The results of the peel tests are summarized in Table 2.

[0170] Table 2

[0171]

[0172] The results of the solubility or peel tests of Table 2 indicate that the coatings from all of the above examples had less than 2% thickness loss in the respective PGMEA and TMAH peel tests.

Claims

1. An etch-resistant antireflective composition for ARC / HM, comprising: A silicone copolymer having the following structure: [R 1 Si(OH)2O 0.5 ] f [R 1 SiO 1.5 ] g [R 1 Si(OH)O] h [R 2 Si(OH)2O 0.5 ] m [R 2 SiO 1.5 ] n [R 2 Si(OH)O] p [Si(OH)3O 0.5 ] r [Si(OH)2O] s [Si(OH)O 1.5 ] t [SiO2] q [R 3 Si(OH)2O 0.5 ] v [R 3 SiO 1.5 ] w [R 3 Si(OH)O] d [R 4 Si(OH)2O 0.5 ] x [R 4 SiO 1.5 ] y [R 4 Si(OH)O] z where 0 < f, g, h, m, n, p, r, s, t, q, v, w, d < 0.9, 0.00 ≤ x, y, z < 0.50 and f + g + h + m + n + p + r + s + t + q + v + w + d + x + y + z = 1, R 1 Each time it appears, it independently represents phenyl, phenylmethyl, phenylethyl, or phenylpropyl. R 2 It's H. R 3 Each time it appears, it independently represents a methyl group or an optionally substituted C2-C5 alkyl group. R 4 Each time it appears, it independently represents 2-[methoxy(polyethyloxy)]. 6-9 [Propyl] or 2-(methyl ester)ethyl.

2. The etch-resistant antireflective composition according to claim 1, wherein the amount of Si in the final copolymer ranges from 8 mol% to 46 mol%.

3. The etch-resistant antireflective composition according to claim 1, wherein the amount of Si in the final copolymer ranges from 15 mol% to 45 mol%.

4. The etch-resistant antireflective composition according to claim 1, wherein the amount of Si in the final copolymer ranges from 35 mol% to 45 mol%.

5. The etch-resistant antireflective composition according to claim 1, wherein the silicone copolymer is prepared by the co-hydrolysis of a mixture of chlorosilane monomers and alkoxysilane monomers in a single synthesis method.

6. The etch-resistant antireflective composition claimed in claim 1, wherein the solvent is a mixture of water and one or more organic solvents selected from ketones, alcohols, ethers, and esters, and the amount of the organic solvent and / or the water in the mixture is 10 wt% - 95 wt%.

7. The etch-resistant and anti-reflective composition claimed in claim 6, wherein the ketone is selected from methyl isobutyl ketone (MIBK), methyl ethyl ketone (MEK), and cyclohexanone; the alcohol is selected from methanol, ethanol, propanol, and isopropanol; and the ether is selected from tetrahydrofuran (THF), ethylene glycol dimethyl ether, ethylene glycol diethyl ether, propylene glycol monomethyl ether (PGME), and diethyl ether. Alkane; the esters are selected from ethyl acetate, butyl acetate, ethyl lactate and propylene glycol monomethyl ether acetate (PGMEA).

8. The etch-resistant antireflective composition according to claim 1, wherein the silicone copolymer has a weight average Mw of 800 to 20,000.

9. A method for coating a microelectronic device, comprising the following steps: i. Preparing the etch-resistant antireflective composition according to any one of claims 1 - 8, ii. Preparing a formulation by dissolving the etch-resistant antireflective composition in a polar organic solvent, iii. Coating the formulation on a substrate, iv. Evaporating the polar organic solvent from the coating, v. Curing the coating to form a thin film.

10. The method claimed in claim 9, wherein in step (ii), the polar organic solvent is selected from ketones, alcohols, ethers, and esters; the solvent in the total ARC / HM formulation of the coating solution can be in an amount of 90 wt% to 99 wt%.

11. The method claimed in claim 10, wherein the ketone is selected from methyl isobutyl ketone (MIBK), methyl ethyl ketone (MEK), and cyclohexanone; the alcohol is selected from methanol, ethanol, propanol, and isopropanol; and the ether is selected from tetrahydrofuran (THF), ethylene glycol dimethyl ether, ethylene glycol diethyl ether, propylene glycol monomethyl ether (PGME), and diethyl ether. Alkane; the esters are selected from ethyl acetate, butyl acetate, ethyl lactate and propylene glycol monomethyl ether acetate (PGMEA).

12. The method claimed in claim 9, wherein in step (v), the curing is carried out in a temperature range of 100 °C - 250 °C.

13. The method claimed in claim 9, wherein in step (v), the curing is carried out for 1 to 2 minutes.

14. The method claimed in claim 9, wherein the substrate is a Si wafer, a substrate of an integrated circuit, or other device substrates.

15. The method claimed in claim 9, wherein in step (iii), the coating is spin coating.

16. The method claimed in claim 9, wherein the polar organic solvent is evaporated during the spin coating process.

17. The method claimed in claim 9, wherein the thickness of the thin film is 10 nm to 200 nm.

18. A method for forming a patterned device, comprising the following steps, a) The formulation is prepared by dissolving the etch-resistant and anti-reflective composition of any one of claims 1-8 in a polar organic solvent and coating the formulation onto the substrate of the device to form a silicon-rich etch-resistant and anti-reflective layer; b) Coat the etch-resistant and anti-reflective layer with ArF photoresist; c) Photopatterning of ArF photoresist and forming a resist pattern on an etch-resistant and anti-reflective layer; d) Remove the exposed areas by etching and produce a patterned device.

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