JP7776265B2 - aromatic lower layer - Google Patents

Description

The present invention relates generally to the field of manufacturing electronic devices, and more specifically to the field of materials for use as underlayers in semiconductor manufacturing.

It is well known in lithography processes that if a resist pattern is too tall (high aspect ratio), it can collapse due to surface tension from the developer used. Multilayer resist processes (e.g., 3- and 4-layer processes) have been devised that can address this problem of pattern collapse when high aspect ratios are desired. Such multilayer processes use a top resist layer, one or more intermediate layers, and a bottom (or underlayer) layer. In such multilayer resist processes, the top photoresist layer is typically imaged and developed to provide a resist pattern. The pattern is then transferred, typically by etching, to one or more intermediate layers. Each intermediate layer is selected to employ a different etch process, such as a different plasma etch. Finally, the pattern is typically transferred to an underlayer by etching. While such intermediate layers can be composed of a variety of materials, the underlayer material is typically composed of a high-carbon content material. The underlayer material is selected to provide desired anti-reflective properties, planarization properties, and etch selectivity.

Current technology for underlayers includes chemical vapor deposition (CVD) carbon and solution-processed high-carbon content polymers. CVD materials have several significant limitations, including high cost of ownership, an inability to form a planarizing layer over topography on the substrate, and high absorbance at 633 nm, which is used for pattern alignment. For these reasons, the industry is moving toward solution-processed high-carbon content materials for underlayers. An ideal underlayer should meet the following properties: it can be cast onto a substrate by a spin-coating process; it can be thermally cured with low outgassing and sublimation upon heating; it is soluble in common processing solvents for good equipment compatibility; it has suitable n and k values to work in conjunction with currently used silicon hard masks and bottom antireflective coating (BARC) layers to provide the low reflectivity required for photoresist imaging; and it is thermally stable up to over 400°C to avoid damage during subsequent silicon oxynitride (SiON) CVD processes.

It is well known that relatively low molecular weight materials have relatively low viscosity and flow into features in a substrate, such as vias and trenches, to provide a planarizing layer. The underlayer material must be capable of planarization at or below 400°C with relatively low outgassing. For use as a high carbon content underlayer, it is essential that any composition be thermally curable upon heating. U.S. Pat. No. 9,581,905 B2 describes a compound of the formula
wherein R ₁ , R ₂ , and R ₃ each independently represent a compound of the formula R ^A -C≡C-R ^B -, where R ^A can be, inter alia, an aryl group substituted with at least one of a hydroxyl group and an aryl group, and R ^B is a single bond or an aryl group, wherein such compounds are useful for forming underlayers in the manufacture of semiconductor devices. Such compounds cure at relatively high temperatures. There remains a need for materials that cure at relatively lower temperatures and that are useful for forming underlayers in semiconductor manufacturing processes.

US Patent No. 9,581,905 B2 U.S. Patent No. 6,136,501 U.S. Patent No. 9,581,905

The present invention provides a coating composition comprising: (a) providing an electronic device substrate; and (b) coating a layer of a coating composition comprising one or more curable compounds on the surface of the electronic device substrate, wherein the one or more curable compounds comprise an aromatic core selected from a C _5-6 aromatic ring and a C _9-30 fused aromatic ring system, and three or more substituents of formula (1):
wherein at least two substituents of formula (1) are attached to an aromatic core; and wherein Ar ¹ is an aromatic ring or fused aromatic ring system having 5 to 30 carbons; Z is a substituent selected from OR ¹ , protected hydroxyl, carboxyl, protected carboxyl, SR ¹ , protected thiol, —O—C(═O)—C _1-6 alkyl, halogen, and NHR ² ; each R ¹ is selected from H, C _1-10 alkyl, C _2-10 unsaturated hydrocarbyl, and C _5-30 aryl; and each R ² is H, C _1-10 alkyl, C _2-10 unsaturated hydrocarbyl, C _5-30 aryl, C(═O)—R ¹ , and S(═O) ₂ —R ¹ ; x is an integer from 1 to 4; and * indicates a point of attachment to the aromatic core; provided that the substituents of formula (1) are not ortho to each other on the same ring of the aromatic core; (c) curing the layer of curable compound to form an underlayer; (d) coating a layer of photoresist onto the underlayer; (e) exposing the photoresist layer to actinic radiation through a mask; (f) developing the exposed photoresist layer to form a resist pattern; and (g) transferring the pattern to the underlayer to expose portions of an electronic device substrate.

Also provided is an electronic device comprising an electronic device substrate having, on a surface of the electronic device substrate, a layer of a polymer comprising, as polymerized units, one or more curable compounds, wherein the one or more curable compounds comprise an aromatic core selected from a C _5-6 aromatic ring and a C _9-30 fused aromatic ring system, and three or more substituents of formula (1):
wherein at least two substituents of formula (1) are attached to an aromatic core; and wherein Ar ¹ is an aromatic ring or fused aromatic ring system having 5 to 30 carbons; Z is a substituent selected from OR ¹ , protected hydroxyl, carboxyl, protected carboxyl, SR ¹ , protected thiol, —O—C(═O)—C _1-6 alkyl, halogen, and NHR ² ; each R ¹ is selected from H, C _1-10 alkyl, C _2-10 unsaturated hydrocarbyl, and C _5-30 aryl; and each R ² is H, C _1-10 alkyl, C _2-10 unsaturated hydrocarbyl, C _5-30 aryl, C(═O)—R ¹ , and S(═O) ₂ —R ¹ ; x is an integer from 1 to 4; and * indicates a point of attachment to the aromatic core; provided that the substituents of formula (1) are not ortho to each other on the same ring of the aromatic core.

The present invention relates to a compound represented by formula (2)
wherein Ar ^c is an aromatic core having 5 to 30 carbon atoms; Ar ¹ , Ar ² , and Ar ³ are each independently an aromatic ring or fused aromatic ring system having 5 to 30 carbons; Y is a single covalent chemical bond, a divalent linking group, or a trivalent linking group; Z ¹ and Z ² are independently a substituent selected from OR ¹ , protected hydroxyl, carboxyl, protected carboxyl, SR ¹ , protected thiol, —O—C(═O)—C _1-6 alkyl, halogen, and NHR ² ; each R ¹ is selected from H, C _1-10 alkyl, C _2-10 unsaturated hydrocarbyl, and C _5-30 aryl; and each R ² is H, C _1-10 alkyl, C _2-10 unsaturated hydrocarbyl, C _5-30 aryl, C(═O)—R ¹ , and S(═O). ₂ -R ¹ is selected from: x1=1 to 4; x2=1 to 4; y1=2 to 4; each y2=0 to 4; y1 + each y2≧3; w=0 to 2; z is equal to 0 to 2; wherein z=1 when Y is a single covalent chemical bond or a divalent linking group; and z=2 when Y is a trivalent linking group; provided that when w=0, Ar ^c and each Ar ¹ is not phenyl.
The present invention further provides a compound of the formula:

Furthermore, the present invention provides a method for producing a compound comprising the steps of: (a) providing an electronic device substrate; (b) forming a compound represented by formula (2):
wherein Ar ^c is an aromatic core having 5 to 30 carbon atoms; Ar ¹ , Ar ² , and Ar ³ are each independently an aromatic ring or fused aromatic ring system having 5 to 30 carbons; Y is a single covalent chemical bond, a divalent linking group, or a trivalent linking group; Z ¹ and Z ² are independently a substituent selected from OR ¹ , protected hydroxyl, carboxyl, protected carboxyl, SR ¹ , protected thiol, —O—C(═O)—C _1-6 alkyl, halogen, and NHR ² ; each R ¹ is selected from H, C _1-10 alkyl, C _2-10 unsaturated hydrocarbyl, and C _5-30 aryl; and each R ² is H, C _1-10 alkyl, C _2-10 unsaturated hydrocarbyl, C _5-30 aryl, C(═O)—R ¹ , and S(═O). _x1 = ^1-4 ; x2=1-4; y1=2-4; each y2=0-4; y1+each y2≧3; w=0-2; z=0-2; and z=0-2; where z=1 when Y is a single covalent chemical bond or a divalent linking group; and z=2 when Y is a trivalent linking group; (c) curing the layer of curable compound to form an underlayer; (d) coating a layer of photoresist on the underlayer; (e) exposing the photoresist layer to actinic radiation through a mask; (f) developing the exposed photoresist layer to form a resist pattern; and (g) transferring the pattern to the underlayer to expose portions of the electronic device substrate.

Also provided by the present invention is a method for filling gaps (or apertures), comprising the steps of: (a) providing a semiconductor substrate having a relief image on a surface thereof, the relief image including a plurality of gaps to be filled; (b) applying a coating layer of one or more compounds of formula (2) over the relief image; and (c) heating the coating layer at a temperature sufficient to cure the coating layer.

When an element is referred to as being "on" another element, it will be understood that it may be directly adjacent to the other element or that intervening elements may be present between them. In contrast, when an element is referred to as being "directly on" another element, there are no intervening elements present. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers, and/or sections, it will also be understood that these elements, components, regions, layers, and/or sections are not to be limited by these terms. These terms are merely used to distinguish one element, component, region, layer, or section from another element, component, region, layer, or section. Thus, a first element, component, region, layer, or section discussed below could be referred to as a second element, component, region, layer, or section without departing from the teachings of the present invention.

As used throughout this specification, the following abbreviations shall have the following meanings unless the context clearly dictates otherwise: °C = degrees Celsius; g = grams; mg = milligrams; L = liters; mL = milliliters; Å = angstroms; nm = nanometers; μm = microns; mm = millimeters; sec. = seconds; min. = minutes; hr. = hours; DI = deionized; and Da = Daltons. "Wt. %" means percent by weight, based on the total weight of the referenced composition, unless otherwise specified. All amounts are percent by weight and all ratios are molar ratios unless otherwise specified. All numerical ranges are inclusive and combinable in any order, except where it is clear that such numerical ranges are constrained to add up to 100%. The articles "a," "an," and "the" refer to singular and plural. "Alkyl" refers to linear, branched, and cyclic alkyl, unless otherwise specified. As used herein, "alkyl" refers to an alkane radical, including alkane monoradicals, diradicals (alkylenes), and higher radicals. "Halo" refers to fluoro, chloro, bromo, and iodo. Unless otherwise noted, "alkyl" includes "heteroalkyl." The term "heteroalkyl" refers to an alkyl group having one or more heteroatoms, such as nitrogen, oxygen, sulfur, or phosphorus, replacing one or more carbon atoms in the radical, as in, for example, an ether or thioether. In a preferred embodiment, "alkyl" does not include "heteroalkyl." When the number of carbons is not specified for any alkyl or heteroalkyl, 1 to 12 carbons are contemplated.

"Aryl" includes aromatic carbocycles and aromatic heterocycles. The term "aryl" refers to an aromatic radical, including monoradicals, diradicals (arylenes), and higher radicals. Preferably, the aryl moiety is an aromatic carbocycle. "Substituted aryl" refers to any aryl moiety in which one or more of its hydrogens has been replaced with one or more substituents selected from halogen, C _1-6 alkyl, halo-C _1-6 alkyl, C _1-6 alkoxy, halo _{-C 1-6 alkoxy} , phenyl, and phenoxy, preferably halogen, C _1-6 alkyl, halo-C _1-4 alkyl, C _1-6 alkoxy, halo-C _1-4 alkoxy, and phenyl, more preferably halogen, _C 1-6 alkyl, C 1-6 alkoxy, phenyl, and phenoxy. Preferably, the substituted aryl has 1 to 3 substituents, more preferably 1 or 2 substituents. As used herein, the term "polymer" includes oligomers. The term "oligomer" refers to dimers, trimers, tetramers, and other polymeric materials that can be further cured. The term "cure" refers to any process, such as polymerization or condensation, that increases the overall molecular weight of the resin, removes solubility-promoting groups from the oligomer, or both increases the overall molecular weight and removes solubility-promoting groups. "Curable" refers to any material that can be cured under specific conditions. As used herein, "gap" refers to any aperture on a semiconductor substrate that is intended to be filled with the gap-fill composition.

The aromatic underlayer can be prepared by the steps of: (a) providing an electronic device substrate; and (b) coating a layer of a coating composition on a surface of the electronic device substrate, the coating composition comprising one or more curable compounds, wherein the one or more curable compounds comprise an aromatic core selected from a C _5-6 aromatic ring and a C _9-30 fused aromatic ring system and three or more substituents of Formula (1):
wherein at least two substituents of formula (1) are attached to an aromatic core; and wherein Ar ¹ is an aromatic ring or fused aromatic ring system having 5 to 30 carbons; Z is selected from OR ¹ , protected hydroxyl, carboxyl, protected carboxyl, SR ¹ , protected thiol, —O—C(═O)—C _1-6 alkyl, halogen, and NHR ² ; each R ¹ is selected from H, C _1-10 alkyl, C _2-10 unsaturated hydrocarbyl, and C _5-30 aryl; and each R ² is H, C _1-10 alkyl, C _2-10 unsaturated hydrocarbyl, C _5-30 aryl, C(═O)—R ¹ , and S(═O) ₂ —R ¹ ; x is an integer from 1 to 4; * indicates a point of attachment to the aromatic core; provided that the substituents of formula (1) are not ortho to each other on the same ring of the aromatic core; (c) curing the layer of curable compound to form an underlayer; (d) coating a layer of photoresist onto the underlayer; (e) exposing the photoresist layer to actinic radiation through a mask; (f) developing the exposed photoresist layer to form a resist pattern; and (g) transferring the pattern to the underlayer to expose portions of the electronic device substrate. The substrate is then patterned and the patterned underlayer is removed. In a preferred embodiment, the layer of photoresist is coated directly onto the underlayer. In an alternative preferred embodiment, one or more layers of a silicon-containing composition, an organic antireflective composition (BARC), and combinations thereof are coated directly onto the underlayer prior to step (d) to form an intermediate layer, and the layer of photoresist is coated directly onto the intermediate layer. When a silicon-containing intermediate layer is used, the pattern is transferred to the silicon-containing intermediate layer after step (f) and before step (g).

A wide variety of electronic device substrates can be used in the present invention, including, for example, packaging substrates such as multichip modules; flat panel display substrates; integrated circuit substrates; substrates for light-emitting diodes (LEDs) such as organic light-emitting diodes (OLEDs); semiconductor wafers; and polycrystalline silicon substrates, with semiconductor wafers being preferred. Such substrates are typically composed of one or more of silicon, polysilicon, silicon oxide, silicon nitride, silicon oxynitride, silicon germanium, gallium arsenide, aluminum, sapphire, tungsten, titanium, titanium-tungsten, nickel, copper, and gold. Suitable substrates may be in the form of wafers such as those used in the manufacture of integrated circuits, optical sensors, flat panel displays, optical integrated circuits, and LEDs. As used herein, the term "semiconductor wafer" is intended to encompass "semiconductor substrates," "semiconductor devices," and various packages for various levels of interconnection, such as single-chip wafers, multiple-chip wafers, packages for various levels, or other assemblies requiring solder connections. Such substrates may be of any suitable size. A preferred wafer substrate diameter is 200 mm to 300 mm, although wafers having smaller and larger diameters may be suitably used in accordance with the present invention. As used herein, the term "semiconductor substrate" includes any substrate having one or more semiconductor layers or structures that may optionally include active or operable portions of a semiconductor device. A semiconductor device refers to a semiconductor substrate upon which at least one microelectronic device has been or is being batch fabricated.

Optionally, a layer of adhesion promoter can be applied to the substrate surface prior to deposition of the coating composition, which is then cured to form the underlayer. If an adhesion promoter is desired, any suitable adhesion promoter for polymer films can be used, such as a silane, preferably an organosilane such as trimethoxyvinylsilane, triethoxyvinylsilane, or hexamethyldisilazane, or an aminosilane coupling agent such as gamma-aminopropyltriethoxysilane. Particularly suitable adhesion promoters include those sold under the designations AP 3000, AP 8000, and AP 9000S, available from Dow Electronic Materials (Marlborough, Massachusetts).

Coating compositions useful in the present invention comprise one or more curable compounds, the one or more curable compounds comprising an aromatic core selected from a _C5-6 aromatic ring and a _C9-30 fused aromatic ring system, and three or more substituents of formula (1):
wherein at least two substituents of formula (1) are attached to an aromatic core; and wherein Ar ¹ is an aromatic ring or fused aromatic ring system having 5 to 30 carbons; Z is selected from OR ¹ , protected hydroxyl, carboxyl, protected carboxyl, SR ¹ , protected thiol, —O—C(═O)—C _1-6 alkyl, halogen, and NHR ² ; each R ¹ is selected from H, C _1-10 alkyl, C _2-10 unsaturated hydrocarbyl, and C _5-30 aryl; and each R ² is H, C _1-10 alkyl, C _2-10 unsaturated hydrocarbyl, C _5-30 aryl, C(═O)—R ¹ , and S(═O) ₂ —R ¹ ; x is an integer from 1 to 4; * indicates a point of attachment to the aromatic core; with the proviso that multiple substituents of formula (1) are not ortho to each other on the same ring of the aromatic core. Thus, multiple substituents of formula (1) attached to the same aromatic ring of the core are not attached to immediately adjacent carbon atoms of the aromatic ring, for example, at positions 1 and 2 of the benzene core. Preferably, each Z is independently selected from OR ¹ , protected hydroxyl, carboxyl (C(═O)OH), protected carboxyl, SH, fluorine, and NHR ^2. More preferably, each Z is independently selected from hydroxyl (OH), protected hydroxyl, OCH ₂ C≡CH, C(═O)OH, protected carboxyl, and NHR ² , still more preferably from OH, protected hydroxyl, OCH ₂ C≡CH, carboxyl, and protected carboxyl, and even more preferably from OH and protected hydroxyl. Each R ¹ is independently selected from H, C _1-10 alkyl, C _2-10 unsaturated hydrocarbyl, and C _5-30 aryl, more preferably H, C _1-10 alkyl, C _2-10 alkenyl, C _2-10 alkynyl, and C _5-30 aryl. In one preferred embodiment, R ¹ is H. Preferably, R ² is selected from H, C _1-10 alkyl, C _2-10 unsaturated hydrocarbyl, and C _5-30 aryl, more preferably H, C _1-10 alkyl, C _2-10 alkenyl, and C _2-10 alkynyl. As used herein, the term "aromatic core" means a single aromatic ring or a fused aromatic ring system to which at least two moieties of formula (1) are attached. The aromatic core may be optionally substituted with one or more substituents selected from a C _1-20 aliphatic or alicyclic moiety and a C _5-30 aryl moiety. Preferably, the aromatic core is selected from pyridine, benzene, naphthalene, quinoline, isoquinoline, carbazole, anthracene, phenanthrene, pyrene, coronene, triphenylene, chrysene, phenalene, benz[a]anthracene, dibenz[a,h]anthracene, and benzo[a]pyrene, more preferably from benzene, naphthalene, carbazole, anthracene, phenanthrene, pyrene, coronene, triphenylene, chrysene, phenalene, benz[a]anthracene, dibenz[a,h]anthracene, and benzo[a]pyrene, even more preferably from benzene, naphthalene, anthracene, phenanthrene, pyrene, coronene, triphenylene, chrysene, and phenalene. In formula (1), each Ar ¹ is preferably independently selected from pyridine, benzene, naphthalene, quinoline, isoquinoline, anthracene, phenanthrene, pyrene, coronene, triphenylene, chrysene, phenalene, benz[a]anthracene, dibenz[a,h]anthracene, and benzo[a]pyrene, more preferably from benzene, naphthalene, anthracene, phenanthrene, pyrene, coronene, triphenylene, chrysene, phenalene, benz[a]anthracene, dibenz[a,h]anthracene, and benzo[a]pyrene, even more preferably from benzene, naphthalene, anthracene, phenanthrene, pyrene, coronene, triphenylene, chrysene, and phenalene. Preferably, x=1 or 2, more preferably x=1. The curable compound has at least three moieties of formula (1), wherein at least two substituents of formula (1) are directly bonded to the aromatic core. The curable compounds may have any suitable number of moieties of formula (1), such as from 3 to 10, preferably from 3 to 8, more preferably from 3 to 6, and even more preferably 3 or 4. It is further preferred that the curable compounds have from 2 to 4 moieties of formula (1) directly attached to the aromatic core.

In one embodiment, preferred curable compounds useful in the present coating compositions are of formula (2):
wherein Ar ^c is an aromatic core having 5 to 30 carbon atoms; Ar ¹ , Ar ² , and Ar ³ are each independently an aromatic ring or fused aromatic ring system having 5 to 30 carbons; Y is a single covalent chemical bond, a divalent linking group, or a trivalent linking group; Z ¹ and Z ² are independently selected from OR ¹ , protected hydroxyl, carboxyl, protected carboxyl, SR ¹ , protected thiol, —O—C(═O)—C _1-6 alkyl, halogen, and NHR ² ; each R ¹ is selected from H, C _1-10 alkyl, C _2-10 unsaturated hydrocarbyl, and C _5-30 aryl; and each R ² is H, C _1-10 alkyl, C _2-10 unsaturated hydrocarbyl, C _5-30 aryl, C(═O)—R ¹ , and S(═O) ₂ -R is selected from ¹ ; x1=1 to 4; x2=1 to 4; y1=2 to 4; each y2=0 to 4; y1 + each y2≧3; w=0 to 2; z is equal to 0 to 2; where z=1 when Y is a single covalent chemical bond or a divalent linking group; and z=2 when Y is a trivalent linking group. Preferably, Ar ^c is an aromatic core having 5 to 25 carbon atoms, more preferably an aromatic core having 5 to 20 carbon atoms. Suitable aromatic cores for ^Arc include, without limitation, pyridine, benzene, naphthalene, quinoline, isoquinoline, carbazole, anthracene, phenanthrene, pyrene, coronene, triphenylene, chrysene, phenalene, benz[a]anthracene, dibenz[a,h]anthracene, and benzo[a]pyrene, preferably benzene, naphthalene, carbazole, anthracene, phenanthrene, pyrene, coronene, triphenylene, chrysene, phenalene, benz[a]anthracene, dibenz[a,h]anthracene, and benzo[a]pyrene, more preferably benzene, naphthalene, anthracene, phenanthrene, pyrene, coronene, triphenylene, chrysene, and phenalene. Ar ¹ is preferably selected from benzene, pyridine, naphthalene, quinoline, isoquinoline, anthracene, phenanthrene, pyrene, coronene, triphenylene, chrysene, phenalene, benz[a]anthracene, dibenz[a,h]anthracene, and benzo[a]pyrene. More preferably, each of Ar ¹ , Ar ² , and Ar ³ is independently selected from pyridine, benzene, naphthalene, quinoline, isoquinoline, anthracene, phenanthrene, pyrene, coronene, triphenylene, chrysene, phenalene, benz[a]anthracene, dibenz[a,h]anthracene, and benzo[a]pyrene, more preferably from benzene, naphthalene, anthracene, phenanthrene, pyrene, coronene, triphenylene, chrysene, phenalene, benz[a]anthracene, dibenz[a,h]anthracene, and benzo[a]pyrene, yet more preferably from benzene, naphthalene, anthracene, phenanthrene, pyrene, coronene, triphenylene, chrysene, and phenalene. It is more preferred that Ar ^c is selected from pyridine, benzene, naphthalene, quinoline, isoquinoline, anthracene, phenanthrene, pyrene, coronene, triphenylene, chrysene, phenalene, benz[a]anthracene, dibenz[a,h]anthracene, and benzo[a]pyrene, and that each of Ar ¹ , Ar ² , and Ar ³ is independently selected from pyridine, benzene, naphthalene, quinoline, isoquinoline, anthracene, phenanthrene, pyrene, coronene, triphenylene, chrysene, phenalene, benz[a]anthracene, dibenz[a,h]anthracene, and benzo[a]pyrene. Preferably, each ^Z1 and ^Z2 is independently selected from ^OR1 , protected hydroxyl, carboxyl (C(=O)OH), protected carboxyl, SH, fluorine, ^NHR2 , more preferably from hydroxyl (OH), protected hydroxyl, _OCH2C≡CH , C(=O)OH, protected carboxyl, and ^NHR2 , yet more preferably from OH, protected hydroxyl, _OCH2C≡CH , carboxyl, and protected carboxyl, and even more preferably from OH and protected hydroxyl. Each ^R1 is independently selected from H, _C1-10 alkyl, _C2-10 unsaturated hydrocarbyl, and _C5-30 aryl, more preferably H, _C1-10 alkyl, _C2-10 alkenyl, _C2-10 alkynyl, and _C5-30 aryl. In one preferred embodiment, ^R1 is H. Preferably, ^R2 is selected from H, _C1-10 alkyl, _C2-10 unsaturated hydrocarbyl, and _C5-30 aryl, more preferably H, _C1-10 alkyl, _C2-10 alkenyl, and _C2-10 alkynyl. Preferably, each ^Z1 is the same. It is also preferred that each ^Z2 is the same. It is further preferred that ^Z1 = ^Z2 . Preferably, each of x1 and x2 is independently selected from 1 to 3, more preferably independently 1 or 2, and even more preferably each is 1. Preferably, each y2 = 0 to 2. Preferably, y1 + each y2 = 3 to 8, more preferably 3 to 6, and even more preferably 3 or 4. Preferably, w = 0 to 1. In one preferred embodiment, none of the substituents, including ^Ar1 and ^Ar3 , are ortho to each other on the same ring of the aromatic core. In one preferred embodiment, when w = 0, ^Arc and each ^Ar1 is not phenyl. In one preferred embodiment, Y is a single covalent bond. In another preferred embodiment, Y is a divalent or trivalent linking group. Exemplary linking groups for Y include, but are not limited to, O, S, N(R ³ ) _r , S(═O) ₂ , CR ⁴ R ⁵ , a bis-imide moiety, a bis-etherimide moiety, a bis-ketoimide moiety, a bis-benzoxazole moiety, a bis-benzimidazole moiety, and a bis-benzothiazole moiety (where r=0 or 1), preferably the linking groups for Y are O, N(R ³ ) _w , and CR ⁴ R ^5. R ³ is **-C(═O)-C _5-30 aryl or **-S(═O) ₂ -C _5-30 aryl (where ** is the point of attachment to N). ^R4 and ^R5 are independently selected from H, _C1-10 alkyl and _C5-10 aryl, and ^R4 and ^R5 together with the carbons to which they are attached may form a 5- or 6-membered ring which may be fused to one or more aromatic rings. When Y = ^{CR4R5 ,} one suitable linking group is a group of formula (A):
(where * indicates the point of attachment to Ar ^c and Ar ² )
and a fluorenyl moiety of the formula: Preferred bis-imide moiety linking groups for Y are shown by formula (B) and formula (C), where Y ¹ is a single covalent bond or a C _5-30 arylene, and * indicates the point of attachment to ^Arc and Ar ^2. Preferred bis-etherimide and bis-ketoimide moieties are of formula (C), where Y ¹ is O or —C(═O)—, respectively, and * indicates the point of attachment to ^Arc and Ar ^2. Preferred bis-benzoxazole, bis-benzimidazole, and bis-benzothiazole moieties are of formula (D), where G is O, NH, and S, respectively, and Y ² is a single covalent bond or a C _5-30 arylene, and * indicates the point of attachment to ^Arc and Ar ² .

The protected carboxyl groups for Z, ^Z1 , and ^Z2 in formulas (1) and (2) are any groups that are cleavable under certain conditions to yield a carboxyl group. Such protected carboxyl groups can be cleaved by heat, acid, base, or a combination thereof, preferably by heat, acid, or a combination thereof, more preferably by heat. Exemplary protected carboxyl groups include esters, such as benzyl esters and esters having a quaternary carbon bonded directly to the alkoxy oxygen of the ester group. Preferably, the protected carboxyl group is an ester having a quaternary carbon bonded directly to the alkoxy oxygen of the ester group, and more preferably, the ester has the formula Y-C(O)-O-CR'R''R''', where Y is an organic residue and each of R', R'', and R''' is independently selected from _C1-10 alkyl. Preferred protected carboxyl groups include tert-butyl esters; 1-alkylcyclopentyl esters such as 1-methylcyclopentyl ester and 1-ethylcyclopentyl ester; 2,3-dimethyl-2-butyl ester; 3-methyl-3-pentyl ester; 2,3,3-trimethyl-3-butyl ester; 1,2-dimethylcyclopentyl ester; 2,3,4-trimethyl-3-pentyl ester; 2,2,3,4,4-pentamethyl-3-pentyl ester; and adamantyl esters such as hydroxyadamantyl ester and C _{alkyladamantyl} ester. Each of the foregoing protected carboxyl groups can be cleaved by one or more of heat, acid, or base. Preferably, the protected carboxyl groups are cleaved using heat, acid, or a combination of heat and acid, more preferably by heat. For example, these protected carboxyl groups can be cleaved at a pH of 4 or less, preferably 1 or less. Such protected carboxyl groups can be cleaved at room temperature when exposed to a pH in the range of 1 to 4. When the pH is less than 1, such protected carboxyl groups are typically heated to approximately 90-110° C., preferably approximately 100° C. Alternatively, if the protected carboxyl group is an ester having a quaternary carbon bonded directly to the alkoxy oxygen of the ester group, it can be cleaved by heating to a suitable temperature, such as above 125° C., preferably 125-250° C., more preferably 150-250° C. Such protected carboxyl groups and conditions for their use are well known in the art, such as U.S. Pat. No. 6,136,501, which discloses a variety of ester groups having a quaternary carbon bonded directly to the alkoxy oxygen of the ester group.

Suitable protected hydroxyl groups for Z, ^Z1 , and ^Z2 in formulas (1) and (2) are any groups that can be cleaved under certain conditions to yield a hydroxy group. Such protected hydroxyl groups can be cleaved by heat, acid, base, or a combination thereof. Exemplary protected hydroxyl groups include ethers such as methoxymethyl ether, tetrahydropyranyl ether, tert-butyl ether, allyl ether, benzyl ether, tert-butyldimethylsilyl ether, tert-butyldiphenylsilyl ether, acetonide, and benzylidene acetal; esters such as pivalate and benzoate; and carbonates such as tert-butyl carbonate. Each of the aforementioned protected hydroxyl groups can be cleaved under acidic or alkaline conditions, preferably under acidic conditions. More preferably, the protected hydroxyl group is cleaved using an acid or a combination of acid and heat. For example, these protected hydroxyl groups can be cleaved at a pH of 4 or less, preferably at a pH of 1 or less. Such protected hydroxyl groups can be cleaved at room temperature when exposed to a pH ranging from 1 to 4. When the pH is less than 1, such protected hydroxyl groups are typically heated to approximately 90-110° C., preferably to approximately 100° C. Such protected hydroxyl groups and the conditions for their use are well known in the art.

Suitable protected thiol groups for Z, ^Z1 , and ^Z2 in formulas (1) and (2) are any groups that can be cleaved under certain conditions to yield a thiol group. Such protected thiol groups can be cleaved by heat, acid, base, or a combination thereof. Exemplary protected thiol groups include ethers such as methoxymethyl thioether, tetrahydropyranyl thioether, tert-butyl thioether, allyl thioether, benzyl thioether, tert-butyldimethylsilyl thioether, tert-butyldiphenylsilyl thioether, thioacetonide, and benzylidene thioacetal; thioesters such as pivalic acid thioester and benzoic acid thioester; and thiocarbonates such as tert-butyl thiocarbonate. Each of the aforementioned protected thiol groups can be cleaved under acidic or alkaline conditions, preferably under acidic conditions. More preferably, the protected thiol group is cleaved using acid or a combination of acid and heat. For example, these protected thiol groups can be cleaved at a pH of 4 or less, preferably at a pH of 1 or less. Such thiol groups can be cleaved at room temperature when exposed to a pH ranging from 1 to 4. When the pH is less than 1, such protected thiol groups are typically heated to approximately 90-110° C., preferably to approximately 100° C. Such protected thiol groups and the conditions for their use are well known in the art.

In addition to the one or more curable compounds described above, the coating composition may optionally contain, and preferably does contain, one or more organic solvents. Suitable organic solvents are any organic solvents that dissolve the one or more curable compounds, preferably organic solvents customarily used in the manufacture of electronic devices. A single organic solvent may be used, or a mixture of organic solvents may be used. Suitable organic solvents include ketones such as cyclohexanone and methyl-2-n-amyl ketone; alcohols such as 3-methoxybutanol, 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol, and 1-ethoxy-2-propanol; ethers such as propylene glycol methyl ether (PGME), propylene glycol ethyl ether (PGEE), ethylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monoethyl ether, propylene glycol dimethyl ether, and diethylene glycol dimethyl ether, and anisole. esters such as propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monoethyl ether acetate, ethyl lactate (EL), methyl hydroxyisobutyrate (HBM), ethyl pyruvate, butyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, tert-butyl acetate, tert-butyl propionate, and propylene glycol mono-tert-butyl ether acetate; lactones such as gamma-butyrolactone, and any combination of the foregoing. Preferred solvents are PGME, PGEE, PGMEA, EL, HBM, and combinations thereof.

The coating composition may also include one or more coating additives typically used in such coatings, such as, for example, a curing agent, a crosslinking agent, a surface leveling agent, etc. The selection of such optional additives and their amounts is well within the capabilities of one skilled in the art. Curing agents are typically present in amounts of 0 to 20 wt %, preferably 0 to 3 wt %, based on total solids. Crosslinking agents are typically used in amounts of 0 to 30 wt %, preferably 3 to 10 wt %, based on total solids. Surface leveling agents are typically used in amounts of 0 to 5 wt %, preferably 0 to 1 wt %, based on total solids. The selection of such optional additives to be used and their amounts is well within the capabilities of one skilled in the art.

A curing agent may optionally be used in the coating composition to aid in the curing of the deposited curable compound. A curing agent is any component that causes the curing of the curable compound on the surface of the substrate. Preferred curing agents are acids and thermal acid generators. Suitable acids include, but are not limited to, arylsulfonic acids such as p-toluenesulfonic acid; alkylsulfonic acids such as methanesulfonic acid, ethanesulfonic acid, and propanesulfonic acid; perfluoroalkylsulfonic acids such as trifluoromethanesulfonic acid; and perfluoroarylsulfonic acids. A thermal acid generator is any compound that liberates an acid upon exposure to heat. Thermal acid generators are well known in the art and are commonly available commercially, for example, from King Industries, Norwalk, Connecticut. Exemplary thermal acid generators include, but are not limited to, amine-blocked strong acids, e.g., amine-blocked sulfonic acids such as amine-blocked dodecylbenzenesulfonic acid. It will also be appreciated by those skilled in the art that certain photoacid generators can liberate acid upon heating and function as thermal acid generators.

Any suitable crosslinker may be used in the composition, provided that the crosslinker has at least two, and preferably at least three, moieties capable of reacting with the aromatic resin reaction product under suitable conditions, such as acidic conditions. Exemplary crosslinkers include, but are not limited to, novolac resins, epoxy-containing compounds, melamine compounds, guanamine compounds, isocyanate-containing compounds, benzocyclobutene, and the like, preferably any of the foregoing crosslinkers having two or more, preferably three or more, and more preferably four, substituents selected from methylol, _C1 - _C10 alkoxymethyl, and _C2 - _C10 acyloxymethyl. Examples of suitable crosslinkers are those represented by formulas (3) and (4).
Such cross-linking agents are well known in the art and are commercially available from a variety of sources.

The coating composition may optionally include one or more surface leveling agents (or surfactants). While any suitable surfactant may be used, such surfactants are typically nonionic. Exemplary nonionic surfactants are those containing alkyleneoxy bonds, such as ethyleneoxy, propyleneoxy, or a combination of ethyleneoxy and propyleneoxy bonds.

The coating composition can be coated onto the electronic device substrate by any suitable means, such as spin coating, slot die coating, doctor blading, curtain coating, roller coating, spray coating, dip coating, etc. Spin coating is preferred. In a typical spin coating method, the composition is applied to a substrate spinning at a speed of 500 to 4000 rpm for a period of 15 to 90 seconds to obtain a desired layer of the coating composition on the electronic device substrate. It will be appreciated by those skilled in the art that the height of the coating composition layer can be adjusted by varying the spin speed.

After being coated onto the substrate, the coating composition layer is optionally baked at a relatively low temperature to remove any organic solvents and other relatively volatile components from the layer. Typically, the substrate is baked at a temperature of 80 to 150°C, although other suitable temperatures may be used. Baking times are typically 10 seconds to 10 minutes, preferably 30 seconds to 5 minutes, although longer or shorter times may be used. When the substrate is a wafer, such a baking step may be carried out by heating the wafer on a hotplate. After solvent removal, a layer, film, or coating of the curable compound is obtained on the surface of the substrate.

The curable compound layer is then cured sufficiently to form an aromatic underlayer that will not intermix with subsequently applied coating layers, such as photoresist or other layers coated directly onto the aromatic underlayer. The underlayer may be cured in an oxygen-containing atmosphere, such as air, or in an inert atmosphere, such as nitrogen, preferably in an oxygen-containing atmosphere. The curing conditions used are sufficient to harden the film so that it will not intermix with subsequently applied organic layers, such as photoresist layers, while still maintaining the desired antireflective properties (n and k values) and etch selectivity of the underlayer film. This curing step is preferably carried out on a hotplate-type apparatus, although oven curing can be used to achieve equivalent results. Typically, such curing is carried out by heating the underlayer to a cure temperature above 150°C, preferably above 170°C, and more preferably above 200°C. The selected cure temperature should be sufficient to cure the aromatic underlayer. Suitable temperature ranges for curing the aromatic underlayer are 150-400°C, preferably 170-350°C, and more preferably 200-250°C. Such a curing process may take from 10 seconds to 10 minutes, preferably from 1 to 3 minutes, and more preferably from 1 to 2 minutes, although other suitable times may also be used.

An initial bake step may not be necessary if the curing process is performed such that rapid release of solvent and curing of by-products does not impair the underlying film quality. For example, a ramp bake starting at a relatively low temperature and then gradually increasing to a temperature of 200°C or higher can produce acceptable results. It may be preferable in some cases to have a two-stage curing process, with the first stage having a lower bake temperature below 150°C and the second stage having a higher bake temperature of 200°C or higher. A two-stage curing process promotes uniform filling and planarization of existing substrate surface topography, such as filling of trenches and vias.

After curing the underlayer, one or more processing layers, such as a photoresist, a silicon-containing layer, a hard mask layer, or a bottom antireflective coating (i.e., BARC) layer, can be coated over the cured underlayer. For example, a photoresist can be coated directly onto the surface of a silicon-containing layer or other interlayer that resides directly on the resin underlayer, e.g., by spin coating, or alternatively, a photoresist can be coated directly onto the cured underlayer. A wide variety of photoresists, such as those used in 193 nm lithography, such as those sold under the EPIC™ brand available from Dow Electronic Materials (Marlborough, Massachusetts), can be suitably used. Suitable photoresists can be either positive-tone or negative-tone developing resists. After coating, the photoresist layer is then imaged (exposed) using patterned actinic radiation, and the exposed photoresist layer is then developed using an appropriate developer to yield a patterned photoresist layer. The pattern is then transferred from the photoresist layer to the underlying layer by a suitable etching technique. Typically, the photoresist is also removed during such an etching step. The pattern is then transferred to the substrate and the underlying layer is removed by a suitable etching technique known in the art, for example, by plasma etching. After patterning the substrate, the underlying layer is removed using conventional techniques. The electronic device substrate is then processed according to conventional means.

The cured underlayer can be used as the bottom layer in a multi-layer resist process. In such a process, a layer of the coating composition is coated on a substrate and cured as described above. One or more intermediate layers are then coated on the aromatic underlayer. For example, a silicon-containing layer or hard mask layer is coated directly on the aromatic underlayer. An exemplary silicon-containing layer, such as a silicon-BARC, can be deposited on the underlayer by spin-coating and subsequent curing, or an inorganic silicon layer, such as SiON or _SiO2 , can be deposited on the underlayer by chemical vapor deposition (CVD). Any suitable hard mask can be used, deposited on the underlayer by any suitable technique, and cured as needed. Optionally, an organic BARC layer can be deposited directly on the silicon-containing layer or hard mask layer and appropriately cured. Next, a photoresist, such as a photoresist used in 193 nm lithography, is coated directly on the silicon-containing layer (in a three-layer process) or directly on the organic BARC layer (in a four-layer process). The photoresist layer is then imaged (exposed) using patterned actinic radiation, and the exposed photoresist layer is then developed using an appropriate developer to produce a patterned photoresist layer. The pattern is then transferred from the photoresist layer to the layer immediately below it by an appropriate etching technique known in the art, such as plasma etching, resulting in a patterned silicon-containing layer in a three-layer process and a patterned organic BARC layer in a four-layer process. If a four-layer process is used, the pattern is then transferred from the organic BARC layer to the silicon-containing layer or hard mask layer using an appropriate pattern transfer technique, such as plasma etching. After the silicon-containing layer or hard mask layer is patterned, the aromatic underlayer is then patterned using an appropriate etching technique, such as _O2 or _CF4 plasma. Any remaining patterned photoresist and organic BARC layer are removed during the etching of the aromatic underlayer. The pattern is then transferred to the substrate, for example by a suitable etching technique, which also removes any remaining silicon-containing or hard mask layers, followed by removal of any remaining patterned aromatic underlayer, resulting in a patterned substrate.

The cured underlayer of the present invention can also be used in a self-aligning double patterning method. In such a method, a layer of the present coating composition is coated onto a substrate, for example, by spin coating. Any remaining organic solvent is removed, and the coating composition layer is cured to form a hardened underlayer. A suitable intermediate layer, such as a silicon-containing layer, is then coated onto the cured underlayer. A layer of a suitable photoresist is then coated onto the intermediate layer, for example, by spin coating. The photoresist layer is then imaged (exposed) using patterned actinic radiation, and the exposed photoresist layer is then developed using a suitable developer to yield a patterned photoresist layer. The pattern is then transferred from the photoresist layer to the intermediate layer and the cured underlayer by a suitable etching technique to expose portions of the substrate. Typically, the photoresist is also removed during such an etching step. A conformal silicon-containing layer is then disposed over the patterned cured underlayer and the exposed portions of the substrate. Such a silicon-containing layer is typically an inorganic silicon layer, such as SiON or _SiO2 , conventionally deposited by CVD. Such conformal coating results in a silicon-containing layer on the exposed portions of the substrate surface and over the underlayer pattern, i.e., such silicon-containing layer substantially covers the sides and top of the patterned underlayer. The silicon-containing layer is then partially etched (trimmed) to expose the top surface of the patterned polyarylene resin underlayer and a portion of the substrate. After this partial etching step, the pattern on the substrate includes a plurality of features, each including a line or post of the cured underlayer, with the silicon-containing layer immediately adjacent to the side of each cured underlayer feature. The hardened underlayer is then removed, for example, by etching, to expose the substrate surface that was underneath the cured underlayer pattern and provide a patterned silicon-containing layer on the substrate surface, where such patterned silicon-containing layer has twice the number of lines and/or posts (i.e., twice the number of lines and/or posts) compared to the patterned hardened underlayer.

The coating compositions of the present invention are also useful for forming planarizing, gap-filling, and protective layers in the manufacture of integrated circuits. When used as such planarizing, gap-filling, or protective layers, one or more intervening layers of material, such as, for example, silicon-containing layers, other aromatic resin layers, hard mask layers, etc., typically reside between the cured layer of the coating composition and any photoresist layers. Typically, such planarizing, gap-filling, and protective layers are ultimately patterned. A gap-filling method according to the present invention includes the steps of: (a) providing a semiconductor substrate having a relief image on a surface thereof, the relief image comprising a plurality of gaps to be filled; and (b) applying a gap-filling composition over the relief image, the gap-filling composition comprising: (i) one or more curable compounds comprising an aromatic core selected from a _C5-6 aromatic ring and a _C9-30 fused aromatic ring system, and three or more substituents of Formula (1).
wherein at least two substituents of formula (1) are attached to an aromatic core; and wherein Ar ¹ is an aromatic ring or fused aromatic ring system having 5 to 30 carbons; Z is a substituent selected from OR ¹ , protected hydroxyl, carboxyl, protected carboxyl, SR ¹ , protected thiol, —O—C(═O)—C _1-6 alkyl, halogen, and NHR ² ; each R ¹ is selected from H, C _1-10 alkyl, C _2-10 unsaturated hydrocarbyl, and C _5-30 aryl; and each R ² is H, C _1-10 alkyl, C _2-10 unsaturated hydrocarbyl, C _5-30 aryl, C(═O)—R ¹ , and S(═O) ₂ —R ¹ ; x is an integer from 1 to 4; * indicates a point of attachment to the aromatic core; with the proviso that the substituents of formula (1) are not ortho to each other on the same ring of the aromatic core; and (ii) one or more organic solvents; and (c) heating the gap-fill composition at a temperature to cure the one or more curable compounds. The composition substantially fills, preferably fills, and more preferably completely fills gaps in a semiconductor substrate.

The compounds of the present invention have good gap-filling properties. Films formed from the compounds of the present invention have good planarization, solvent resistance, and reduced defect formation compared to the compounds disclosed in U.S. Pat. No. 9,581,905.

Example 1. 1,3,5-Tribromobenzene (2.36 g), cuprous iodide (0.21 g), and triethylamine (3.42 g) were added to 20 g of 1,4-dioxane at room temperature. The reaction mixture was purged with nitrogen for 1 hour. Bis(triphenylphosphine)palladium(II) chloride (0.53 g) was added to the reaction mixture, and the mixture was heated to 70°C. 4-Ethynylphenyl acetate (4.81 g) was dissolved in degassed 1,4-dioxane (14 g), and this solution was then slowly added to the reaction mixture via an addition funnel. After the addition was complete, the reaction mixture was stirred overnight at 70°C under nitrogen. After the reaction was complete, the reaction mixture was cooled to room temperature, filtered, and the solvent was evaporated. The residue was purified by column chromatography to give 1,3,5-tris((4-acetoxyphenyl)ethynyl)benzene (compound I1) as a pale yellow solid, 3.5 g (84% yield). The reaction is shown in the following reaction scheme.
Reaction Scheme 1

Example 2. 1,3,5-Tribromobenzene (2.36 g), cuprous iodide (0.21 g), and triethylamine (3.42 g) were added to 20 g of 1,4-dioxane at room temperature. The reaction mixture was purged with nitrogen for 1 hour. Bis(triphenylphosphine)palladium(II) chloride (0.53 g) was added to the reaction mixture, and the mixture was heated to 70°C. 4-Ethynylphenyl acetate (4.81 g) was dissolved in degassed 1,4-dioxane (14 g), and this solution was then slowly added to the reaction mixture via an addition funnel. After the addition was complete, the reaction mixture was stirred overnight at 70°C under nitrogen. After the reaction was complete, the reaction mixture was cooled to room temperature, filtered, and the solvent was evaporated. The residue was purified by column chromatography to give a pale yellow solid. The resulting solid was then dissolved in THF (35 g) under nitrogen. Lithium hydroxide monohydrate (0.94 g) and water (8 g) were added, and the reaction mixture was stirred at 60° C. for 1 hour. The reaction mixture was then diluted with ethyl acetate and then treated with hydrochloric acid until the pH of the aqueous layer was 1. The organic phase was separated, and the aqueous phase was extracted with ethyl acetate. The organic layers were combined and washed with water. The solvent was removed under reduced pressure to give 1,3,5-tris((4-hydroxyphenyl)ethynyl)benzene (compound I2) as a pale yellow solid, 2.6 g (81% yield). The reaction is shown in the following reaction scheme:
Reaction Scheme 2

Example 3. 4-Iodophenylacetate (24.75 g), cuprous iodide (0.17 g), and triethylamine (27.32 g) were added to 22.82 g of 1,4-dioxane at room temperature. The reaction mixture was purged with nitrogen for 1 hour. Bis(triphenylphosphine)palladium(II) chloride (0.63 g) was added to the reaction mixture, and the mixture was heated to 70°C. A solution of 1,3,5-triethynylbenzene (4.5 g) in degassed 1,4-dioxane (20 g) was then slowly added to the reaction mixture via syringe pump. After the addition was complete, the reaction was stirred overnight at 70°C under nitrogen. After the reaction was complete, the reaction mixture was cooled to room temperature and the solvent was evaporated. The residue was diluted with ethyl acetate and filtered to remove solids. The solution was evaporated, and the residue was purified by column chromatography to give a pale yellow solid. The resulting solid was then dissolved in THF (38 g) under nitrogen. Lithium hydroxide monohydrate (3.81 g) and water (16 g) were added, and the mixture was stirred at 60° C. for 1 hour. The mixture was then cooled to room temperature, and the solvent was removed. The residue was diluted with ethyl acetate and water, and then treated with hydrochloric acid until the pH of the aqueous layer was 1. The organic phase was separated, and the aqueous phase was extracted with ethyl acetate. The organic layers were combined and washed with water. The solvent was removed under reduced pressure, and the residue was purified by column chromatography to give 1,3,5-tris((4-hydroxyphenyl)ethynyl)benzene (Compound I2) as a pale yellow solid, 7.7 g (61% yield). This reaction is shown in the following reaction scheme:
Reaction Scheme 3

Example 4. 1,3,5-Tribromobenzene (3.12 g), cuprous iodide (0.29 g), and triethylamine (4.55 g) were added to 22 g of 1,4-dioxane at room temperature. The reaction mixture was purged with nitrogen for 1 hour. Bis(triphenylphosphine)palladium(II) chloride (0.70 g) was added to the reaction mixture, and the mixture was heated to 70°C. 1-Ethynyl-4-methoxybenzene (5.28 g) was dissolved in degassed 1,4-dioxane (20 g), and this solution was then slowly added to the reaction mixture via an addition funnel. After the addition was complete, the reaction mixture was stirred overnight at 70°C under nitrogen. After the reaction was complete, the mixture was cooled to room temperature, filtered, and the solvent was evaporated. The residue was purified by column chromatography to give 1,3,5-tris((4-methoxyphenyl)ethynyl)benzene (compound I3) as a pale yellow solid, 4.0 g (85% yield). The reaction is shown in the following reaction scheme.
Reaction Scheme 4

Example 5. 1,3,5-Tribromobenzene (3.12 g), cuprous iodide (0.29 g), and triethylamine (4.55 g) were added to 22 g of 1,4-dioxane at room temperature. The reaction mixture was purged with nitrogen for 1 hour. Bis(triphenylphosphine)palladium(II) chloride (0.70 g) was added to the reaction mixture, and the mixture was heated to 70°C. 4-Ethynylaniline (4.68 g) was dissolved in degassed 1,4-dioxane (20 g), and this solution was then added slowly to the reaction mixture via an addition funnel. After the addition was complete, the reaction mixture was stirred overnight at 70°C under nitrogen. After the reaction was complete, the reaction mixture was cooled to room temperature, filtered, and the solvent was evaporated. The residue was purified by column chromatography to give 1,3,5-tris((4-aminophenyl)ethynyl)benzene (compound I4) as a yellow solid, 1.5 g (36% yield). The reaction is shown in the following reaction scheme.
Reaction Scheme 5

Example 6. 1,3,5-Tribromobenzene (15.0 g) was added to 40.0 g of 1,4-dioxane at room temperature to give a clear, colorless solution. Triethylamine (14.5 g) and cuprous iodide (0.91 g) were added to the reaction mixture. The reaction mixture was purged with nitrogen for 1 hour. Bis(triphenylphosphine)palladium(II) chloride (1.00 g) was added to the reaction mixture. Next, 22.9 g of 4-fluorophenylacetylene was slowly added to the reaction mixture via an addition funnel. After the addition was complete, the reaction mixture was stirred under nitrogen at 55°C for 24 hours. The reaction mixture was filtered and the solvent was evaporated. The residue was dissolved in heptane and filtered through a silica plug. After filtration, the solvent was removed to give 1,3,5-tris((4-fluorophenyl)ethynyl)benzene (compound I5) as a pale yellow solid (8.0 g) in 39% yield. This reaction is shown in the following reaction scheme:
Reaction Scheme 6

Example 7. 5,5'-Oxybis(1,3-dibromobenzene) (3.61 g), cuprous iodide (0.21 g), and triethylamine (3.42 g) were added to 20 g of 1,4-dioxane at room temperature. The reaction mixture was purged with nitrogen for 1 hour. Bis(triphenylphosphine)palladium(II) chloride (0.53 g) was added to the reaction mixture, and the mixture was heated to 70°C. 4-Ethynylphenyl acetate (4.81 g) was dissolved in degassed 1,4-dioxane (17 g), and this solution was then slowly added to the reaction mixture via an addition funnel. After the addition was complete, the reaction mixture was stirred overnight at 70°C under nitrogen. After the reaction was complete, the reaction mixture was cooled to room temperature, filtered, and the solvent was evaporated. The residue was purified by chromatography to give a pale yellow solid. The resulting solid was then dissolved in THF (40 g) under nitrogen. Lithium hydroxide monohydrate (1.26 g) and water (10 g) were added, and the mixture was stirred at 60° C. for 1 hour. The reaction mixture was then diluted with ethyl acetate and then treated with hydrochloric acid until the pH of the aqueous layer was 1. The organic phase was separated, and the aqueous phase was extracted with ethyl acetate. The organic layers were combined and washed with water. The solvent was removed under reduced pressure, and the residue was purified by column chromatography to give 5,5′-oxybis(1,3-di((4-hydroxyphenyl)ethynyl)benzene) (compound I6) as a pale yellow solid, 3.1 g (65% yield). The reaction is shown in the following reaction scheme:
Reaction Scheme 7

Example 8. 9,9-Bis(6-(3,5-dibromophenoxy)naphthalen-2-yl)-9H-fluorene (6.85 g), cuprous iodide (0.21 g), and triethylamine (3.42 g) were added to 25 g of 1,4-dioxane at room temperature. The reaction mixture was purged with nitrogen for 1 hour. Bis(triphenylphosphine)palladium(II) chloride (0.53 g) was added to the reaction mixture, and the mixture was heated to 70° C. 4-Ethynylphenyl acetate (4.81 g) was dissolved in degassed 1,4-dioxane (22 g), and this solution was then added slowly to the reaction mixture via an addition funnel. After the addition was complete, the reaction mixture was stirred overnight at 70° C. under nitrogen. After the reaction was complete, the reaction mixture was cooled to room temperature, filtered, and the solvent was evaporated. The residue was purified by chromatography to give a pale yellow solid. The resulting solid was then dissolved in THF (40 g) under nitrogen. Lithium hydroxide monohydrate (1.26 g) and water (10 g) were added, and the mixture was stirred at 60° C. for 1 hour. The reaction mixture was then diluted with ethyl acetate and then treated with hydrochloric acid until the pH of the aqueous layer was 1. The organic phase was separated, and the aqueous phase was extracted with ethyl acetate. The organic layers were combined and washed with water. The solvent was removed under reduced pressure, and the residue was purified by column chromatography to give 9,9-bis(6-(3,5-di((4-hydroxyphenyl)ethynyl)phenoxy)naphthalen-2-yl)-9H-fluorene (compound I7) as a pale yellow solid, 4.7 g (59% yield). The reaction is shown in the following reaction scheme:
Reaction Scheme 8

Example 9. 1,3,5-Trisbromobenzene (2.83 g), cuprous iodide (0.17 g), and triethylamine (4.10 g) were added to 20 g of 1,4-dioxane at room temperature. The reaction mixture was purged with nitrogen for 1 hour. Bis(triphenylphosphine)palladium(II) chloride (0.32 g) was added to the reaction mixture, and the mixture was heated to 70°C. 2-((6-ethynylnaphthalen-2-yl)oxy)tetrahydro-2H-pyran (6.81 g) was dissolved in degassed 1,4-dioxane (13 g), and this solution was then added slowly to the reaction mixture via an addition funnel. After the addition was complete, the reaction mixture was stirred overnight at 70°C under nitrogen. After the reaction was complete, the reaction mixture was cooled to room temperature, filtered, and the solvent was evaporated. The residue was purified by column chromatography to give a white solid. The resulting solid was then dispersed in MeOH (54 g) under nitrogen. 12 N HCl (4.5 g) and water (54 g) were added, and the mixture was refluxed at 60° C. overnight. The reaction mixture was then cooled to room temperature, and the solvent was removed under reduced pressure. The residue was diluted with ethyl acetate, the organic phase was separated, and the aqueous phase was extracted with ethyl acetate. The organic layers were combined and washed with water. The solvent was removed under reduced pressure, and the residue was purified by column chromatography to give 1,3,5-tris((2-hydroxynaphthyl-6-ethynyl)benzene (compound I8) as a white solid, 1.1 g (21% yield). The reaction is shown in the following reaction scheme:
Reaction Scheme 9

Compound I2 (6.0 g) in 46 g of anhydrous DMF was stirred at room temperature for 15 minutes. This mixture was heated to 30°C, and 10.34 _g of _K2CO3 was then added. The reaction was then allowed to heat to 50°C, and 8.63 g of a solution of propargyl bromide (80% in toluene) was added dropwise via an addition funnel. The reaction mixture was heated at 50°C for 24 hours. The reaction was then allowed to cool to room temperature and filtered to remove most of _{the K2CO3} . The organics were precipitated in 2 L of water and stirred at room temperature for 0.5 hours. The precipitated polymer was collected by filtration to give a solid (17.8 g) after drying under vacuum at 35°C for 1 day.
Reaction Scheme 10

Comparative Example 1. 1,3,5-Tris(4-bromophenyl)benzene (4.05 g), cuprous iodide (0.21 g), and triethylamine (3.42 g) were added to 20 g of 1,4-dioxane at room temperature. The reaction mixture was purged with nitrogen for 1 hour. Bis(triphenylphosphine)palladium(II) chloride (0.53 g) was added to the reaction mixture, and the mixture was heated to 70°C. 4-Ethynylphenyl acetate (4.81 g) was dissolved in degassed 1,4-dioxane (14 g), and this solution was then slowly added to the reaction mixture via an addition funnel. After the addition was complete, the reaction mixture was stirred overnight at 70°C under nitrogen. After the reaction was complete, the reaction mixture was cooled to room temperature, filtered, and the solvent was evaporated. The residue was purified by chromatography to give a pale yellow solid. The resulting solid was then dissolved in THF (35 g) under nitrogen. Lithium hydroxide monohydrate (0.94 g) and water (8 g) were added, and the mixture was stirred at 60° C. for 1 hour. The reaction mixture was then diluted with ethyl acetate and then treated with hydrochloric acid until the pH of the aqueous layer was 1. The organic phase was separated, and the aqueous phase was extracted with ethyl acetate. The organic layers were combined and washed with water. The solvent was removed under reduced pressure, and the residue was purified by column chromatography to give 1,3,5-tris((4-(4-hydroxyphenyl)ethynyl)phenyl)benzene (Comparative 1) as a pale yellow solid, 2.2 g (44% yield). The reaction is shown in the following reaction scheme:
Reaction Scheme 10

Example 10. Solubility was evaluated by mixing the compounds of the present invention with PGME and PGMEA at 5% solids. The mixtures were visually inspected and checked using a turbidity meter (Orbeco-Hellige Co.). If the turbidity value was less than 1, the compound was rated as soluble ("S"); if the turbidity value was greater than 1, it was rated as not soluble ("NS"). The results are reported in Table 1. As can be seen from these data, the compounds of the present invention and the comparative compounds are all soluble in PGME and PGMEA, respectively.

Example 11. The thermal stability of compounds of the present invention was evaluated using a TA-Instruments Thermogravimetric Analyzer (TGA) Q500 under the following conditions: under _N2 at a 10°C/min heating rate up to 700°C; and under air at a 10°C/min heating rate up to 700°C. The temperatures at which the materials lost 5% of their weight ("Td _5% ") are reported in Table 2.

Example 12. Solvent stripping resistance was measured as an indicator of film crosslinking. Compositions of the compounds of the present invention and Comparative Compound 1 were prepared in a mixture of PGMEA and benzyl benzoate at 4.5% solids. Each composition was spin-coated onto an 8-inch (200 mm) silicon wafer at 1500 rpm using an ACT-8 Clean Track (Tokyo Electron Limited) and then baked for 60 seconds at the temperatures reported in Table 3 to form films. The initial film thickness was measured using an OptiProbe™ manufactured by Therma-Wave Co. Next, a commercially available remover, OK73 (PGME/PGMEA = 70/30), was applied to each film for 90 seconds, followed by a post-stripping bake step at 105°C for 60 seconds. The thickness of each film after the post-stripping bake was measured again to determine the amount of film thickness lost. The difference in film thickness before and after contact with the remover is reported in Table 3 as a percentage of remaining film thickness. As can be seen from the data, films formed from the compounds of the present invention retained over 99% of their thickness, while the film formed from Comparative Compound 1 retained only 12% of its film thickness after contact with the remover (i.e., it lost 88% of its thickness).

Example 13. Compositions of the compounds of the present invention and Comparative Compound 1 were prepared in a mixture of PGMEA and benzyl benzoate at 4.5% solids. Each composition was spin-coated onto an 8-inch (200 mm) silicon wafer at 1500 rpm using an ACT-8 Clean Track (Tokyo Electron Limited) and then baked for 60 seconds at the temperature specified in Table 4 to form a cured film. Optical constants were measured at 193 nm using a Vacuum Ultra-Violet Variable Angle Ellipsometer (VUV-VASE, Woollam Co.) and are reported in Table 4.

Example 14. Compounds of the present invention were evaluated to determine their gap-filling properties. Gap-filling templates were fabricated at CNSE Nano-FAB (Albany, NY). The templates had a 100 nm _SiO2 film thickness and various pitches and patterns. Prior to coating the coupons with the compositions, the template coupons were baked at 150°C for 60 seconds as a dehydration bake. Each coating composition (4.5% solids in a mixture of PGMEA, benzyl benzoate, and PolyFox PF656) was coated onto the template coupons using an ACT-8 Clean Track (Tokyo Electron Limited) spin coater and a spin speed of 1500 rpm +/- 200 rpm. The target film thickness was 100 nm after curing, and the composition dilution was adjusted accordingly to obtain approximately the target film thickness after curing. The films were cured by placing the wafer on a hotplate for 60 seconds at the temperature specified in Table 5. Cross-sectional scanning electron microscope (SEM) images of the coated coupons were collected using a Hitachi S4800 SEM (Hitachi High-Technologies). The planarization quality of the films was obtained from the SEM images using Hitachi offline CD measurement software or CDM software by measuring the difference in thickness (ΔFT) between the deep grooves and open areas of the film. Films with a ΔFT < 20 nm were considered to have "good" planarization, and films with a ΔFT > 20 nm were considered to have "poor" planarization. Gap filling was assessed by visually inspecting the SEM images to see if there were any voids or bubbles in the groove pattern. Films without voids in the groove pattern were considered to have "good" gap filling, and films with voids in the groove pattern were considered to have "poor" gap filling. These results are reported in Table 5.

Example 15. Compositions of the compounds of the present invention and comparative compound 1 were prepared in PGMEA at 4.5% solids. Each composition was spin-coated onto an 8-inch (200 mm) silicon wafer at a speed of 1500 rpm using an ACT-8 Clean Track (Tokyo Electron Limited), and then baked for 60 seconds at the temperature reported in Table 6 to form a cured film. The coating quality was evaluated by visual inspection of the films, and the results are reported in Table 6.

Example 16. Each underlayer solution (4.5% solids in a mixture of PGMEA and benzyl benzoate) was spin-coated onto a 200 mm silicon wafer at 1500 rpm using an ACT-8 Clean Track with a target film thickness of 100 nm after curing. A virgin silicon wafer was placed upside down on top of the coated wafer with three (2 mm) spacers on the edge. This stack of wafers, with the coated wafer on the bottom, was baked on a hot plate for 60 seconds at the temperature specified in Table 7. The top wafer was inspected for haze (indicating sublimation) and defects using a 500 nm sensitive SP2 defect tool (manufactured by KLA-Tencor Corporation). As can be seen from the data in Table 7, Comparative Compound 1 exhibits significantly higher defect counts and defect densities than Inventive Compound I2.

Claims (9)

(a) providing an electronic device substrate;
(b) Formula 2:
(In the formula,
Ar ^c is an aromatic core having 5 to 30 carbon atoms;
Ar ¹ , Ar ² and Ar ³ are each independently an aromatic ring or fused aromatic ring system having 5 to 30 carbons;
Y is a single covalent chemical bond, a divalent linking group, or a trivalent linking group;
Z ¹ and Z ² are independently substituents selected from OR ¹ , protected hydroxyl, carboxyl, protected carboxyl, SR ¹ , protected thiol, halogen, and NHR ² ;
each R ¹ is selected from H, C _1-10 alkyl, C _2-10 unsaturated hydrocarbyl, and C _5-30 aryl;
each R ² is selected from H, C _1-10 alkyl, C _2-10 unsaturated hydrocarbyl, C _5-30 aryl, C(═O)—R ¹ , and S(═O) ₂ —R ¹ ;
x1=1 to 4;
x2=1 to 4;
y1=2 to 4;
each y2=0 to 4;
y1 + each y2 ≥ 3;
w=0 to 2;
z is equal to 0 to 2, where z=1 when Y is a single covalent chemical bond or a divalent linking group, and z=2 when Y is a trivalent linking group;
None of the substituents, including Ar1 and Ar3 ^{, are} ortho to each other on the same ring of the aromatic core.
coating a layer of a coating composition comprising one or more curable compounds of the formula (I) onto a surface of the electronic device substrate;
(c) curing the layer of the curable compound to form an underlayer;
(d) coating a layer of photoresist onto the underlayer;
(e) exposing the photoresist layer to actinic radiation through a mask;
(f) developing the exposed photoresist layer to form a resist pattern;
(g) transferring the pattern into the underlying layer to expose portions of the electronic device substrate. The method of claim 1, further comprising: patterning the substrate; and then removing the patterned underlayer. The method of claim 1, further comprising, prior to step (d), coating the underlayer with one or more of a silicon-containing layer, an organic anti-reflective coating layer, and combinations thereof. The method of claim 3, further comprising, after step (f) and before step (g), transferring the pattern to one or more of the silicon-containing layer, the organic antireflective coating layer, and the combination thereof. 2. The method of claim 1, wherein each Z is independently selected from OR ^<1> , protected hydroxyl, carboxyl, protected carboxyl, SH, fluorine, and NHR ^<2> . The method of claim 1, wherein the aromatic core is selected from pyridine, benzene, naphthalene, quinoline, isoquinoline, anthracene, phenanthrene, pyrene, coronene, triphenylene, chrysene, phenalene, benz[a]anthracene, dibenz[a,h]anthracene, and benzo[a]pyrene. 2. The method of claim 1, wherein each Ar ¹ is independently selected from pyridine, benzene, naphthalene, quinoline, isoquinoline, anthracene, phenanthrene, pyrene, coronene, triphenylene, chrysene, phenalene, benz[a]anthracene, dibenz[a,h]anthracene, and benzo[a]pyrene. The method of claim 1, wherein the coating composition further comprises one or more of an organic solvent, a curing agent, and a surface leveling agent. On the surface of the electronic device substrate, a polymerized unit of Formula 2:
(In the formula,
Ar ^c is an aromatic core having 5 to 30 carbon atoms;
Ar ¹ , Ar ² , and Ar ³ are each independently an aromatic ring or fused aromatic ring system having 5 to 30 carbons;
Y is a single covalent chemical bond, a divalent linking group, or a trivalent linking group;
Z ¹ and Z ² are independently substituents selected from OR ¹ , protected hydroxyl, carboxyl, protected carboxyl, SR ¹ , protected thiol, halogen, and NHR ² ;
each R ¹ is selected from H, C _1-10 alkyl, C _2-10 unsaturated hydrocarbyl, and C _5-30 aryl;
each R ² is selected from H, C _1-10 alkyl, C _2-10 unsaturated hydrocarbyl, C _5-30 aryl, C(═O)—R ¹ , and S(═O) ₂ —R ¹ ;
x1=1 to 4;
x2=1 to 4;
y1=2 to 4;
each y2=0 to 4;
y1 + each y2 ≥ 3;
w=0 to 2;
z is equal to 0 to 2, where z=1 when Y is a single covalent chemical bond or a divalent linking group, and z=2 when Y is a trivalent linking group;
None of the substituents, including Ar1 and Ar3 ^{, are} ortho to each other on the same ring of the aromatic core.
10. An electronic device comprising an electronic device substrate as described above having a layer of a polymer comprising one or more curable compounds of the formula :