Placement of auxiliary features in semiconductor patterning

Abstract

The microfabrication method comprises the steps of: providing a substrate having an existing pattern, wherein the existing pattern includes features formed within a base layer such that the top surface of the substrate has uncovered features and the base layer is not covered; depositing a selective adhesive on the substrate, wherein the selective adhesive includes a solubility converter; depositing a first resist on the substrate; activating the solubility converter so that a portion of the first resist becomes insoluble in a first developer; and developing the first resist using a first developer so that a portion of the first resist insoluble in the first developer remains.

Description

Background Technology

[0001] Microfabrication of semiconductor devices involves various steps, such as film deposition, pattern formation, and pattern transfer. Materials and films are deposited onto a substrate via spin coating, vapor deposition, and other deposition processes. Pattern formation is performed by exposing a photosensitive film, generally known as photoresist, to a chemical radiation pattern and then developing the photoresist to form a relief pattern. The relief pattern acts as an etching mask that covers the portion of the substrate that will not be etched when one or more etching processes are applied to the substrate. Accordingly, a pattern constituting a functional device (e.g., transistors and diodes) is formed on the substrate, and then further processed.

[0002] Semiconductor patterning involves a routine processing flow. A pattern is applied to a substrate layer. This pattern is planarized, and a transfer layer is placed to improve the pattern shape. Next, a photoresist and associated layers are deposited on the surface. The photoresist layer is exposed to the pattern via lithography to create a latent pattern. The latent pattern is then developed to form a relief pattern resistant to the etchant used as an etching mask. Finally, this relief pattern is etched onto the transfer layer and then etched onto the final substrate. means of solving the problem

[0003] This summary is provided to introduce the selection of concepts further described in the detailed description below. This summary is not intended to identify the principal or essential features of the claimed essence, nor is it intended to help limit the scope of the claimed essence.

[0004] In one embodiment, the embodiments disclosed herein relate to a microfabrication method, the method comprising the steps of: providing a substrate having a pre-existing pattern, wherein the pre-existing pattern comprises features formed within a base layer such that the top surface of the substrate has uncovered features and the base layer is not covered; depositing a selective adhesive on the substrate, wherein the selective adhesive comprises a solubility converter; depositing a first resist on the substrate; activating the solubility converter such that a portion of the first resist becomes insoluble in a first developer; and developing the first resist using a first developer such that a portion of the first resist insoluble in the first developer remains.

[0005] In another aspect, an embodiment of the present disclosure relates to a microfabrication method, the method comprising the steps of: providing a substrate having a prior pattern, wherein the prior pattern comprises features formed within a base layer such that the top surface of the substrate has uncovered features and the base layer is not covered; depositing a selective adhesive on the substrate, wherein the selective adhesive comprises a solubility converter; depositing a first resist on the substrate; activating the solubility converter so that a portion of the first resist becomes soluble in a first developer; and developing the first resist using a first developer so that a portion of the first resist soluble in the first developer is removed.

[0006] Other aspects and advantages of the claimed essence will become apparent from the following description and the appended claims. Brief explanation of the drawing

[0007] FIG. 1a is a schematic depiction of a selective self-aligned pattern on a substrate according to one or more embodiments of the present disclosure. FIG. 1b is a schematic depiction of a semi-selective self-aligned pattern on a substrate according to one or more embodiments of the present disclosure. FIG. 2 is a block flowchart of a method according to one or more embodiments of the present disclosure. FIGS. 3a through 3e are schematic diagrams of a substrate coated at each point of the method according to one or more embodiments of the present disclosure. FIG. 4 is a block flowchart of a method according to one or more embodiments of the present disclosure. FIGS. 5a through 5d are schematic diagrams of a substrate coated at each point of the method according to one or more embodiments of the present disclosure. Specific details for implementing the invention

[0008] The challenge of substrate patterning is to accurately shape the final pattern by precisely placing the designed pattern on the fundamental features. Another challenge is to accurately adjust the size of the final pattern as designed. Even small variations in size and shape can lead to short-term and long-term device failures.

[0009] As understood by those skilled in the art, films and materials added to and removed from a given substrate can apply internal compressive and tensile stresses to the substrate based on the material and structure of the shape formed thereon. These internal stresses can cause the substrate to warp or bend. Furthermore, printing patterns below the resolution of a given photolithography tool often implies a higher probability of incorrect pattern placement. Therefore, a significant challenge is that a placed (exposed) pattern may offset a previous pattern. This "registration" or "overlay" error is one of the most critical challenges in device microfabrication. This challenge applies not only to layers stacked on top of each other but also to layers adjacent to each other.

[0010] Therefore, there is a high demand for improvement in pattern placement for a given subsequent layer. Conventional attempts to improve pattern placement in lithography systems tend to use very accurate measurements and complex feedback loops.

[0011] The present disclosure generally relates to a method for placing a pattern on a semiconductor substrate. In this disclosure, the terms “semiconductor substrate” and “substrate” are used interchangeably and may be any semiconductor material, including but not limited to semiconductor wafers, semiconductor material layers, and combinations thereof. The method disclosed herein provides a pattern placement and overlay that is locally and directly improved by inducing the pattern to be formed at a correct location (e.g., a target location or a target region). To achieve a self-aligned pattern placement, the method may include indicating the location where the pattern is formed or preventing the pattern from being formed at an undesirable location. In one or more embodiments, the method includes the step of depositing or forming an auxiliary layer at a target location.

[0012] A method according to the present disclosure may include the steps of providing a substrate having an existing pattern, and then selectively forming a pattern of material on top of or alternately with the existing pattern. According to one or more embodiments, a pattern of material selectively formed on top of an existing pattern is shown in FIG. 1a. According to one or more embodiments, a pattern of material selectively formed on a substrate, replacing or offset from an existing pattern included therein, is shown in FIG. 1b.

[0013] A method (200) for selective pattern self-alignment (e.g., the pattern shown in FIG. 1a) according to the present disclosure is shown in FIG. 2 and is discussed with reference thereto. First, in block (202), an existing pattern is provided on a substrate. In block (204), the substrate or a part thereof is coated with a selective adhesive. The selective adhesive may covalently bond with the surface. The selective adhesive coating may optionally be pretreated. The optional pretreatment may be a heat treatment. The heat treatment may promote a condensation reaction between the selective adhesive and the surface. Next, in block (206), the substrate is coated with a first resist. A solubility converter may be provided on the first resist, and as shown in block (208), the solubility converter may be activated to provide a region of the first resist that is soluble in the first developer. Finally, in block (210), the first resist is developed to provide a selective pattern of the first resist.

[0014] Schematic depictions of a substrate coated at various points during the method described above are shown in FIGS. 3a through 3e. As used herein, "coated substrate" refers to a substrate coated with one or more layers, such as a first resist layer and a second resist layer. FIG. 3a shows a substrate containing an existing pattern. FIG. 3b shows a substrate containing an overcoat containing a selective adhesive. FIG. 3c shows a substrate containing a selective adhesive overcoat laminated with a first resist. Finally, FIG. 3d shows a coated substrate after the first resist has been developed so that a portion of the substrate is exposed. The method of FIG. 2 and the coated substrates shown in FIGS. 3a through 3d are discussed in detail below.

[0015] In block (202) of FIG. 2, a conventional pattern is provided on a substrate. FIG. 3a shows a substrate including the conventional pattern. In FIG. 3a, the conventional pattern includes a feature (302) formed on a base layer (301). The base layer may be any suitable substrate known in the art. In one or more embodiments, the feature includes a metal or other conductive structure. As used herein, the term metal includes alloys, stacks, and other combinations of multiple metals. For example, metal interconnect lines may include a barrier layer, a stack of various metals or alloys, etc. Suitable metals that may be present in the feature include, but are not limited to, copper, cobalt, and tungsten. In one or more embodiments, the base layer is an interlayer dielectric. Suitable interlayer dielectrics may include silicon oxides (e.g., silicon dioxide (SiO2)), doped silicon oxides, fluorinated silicon oxides, carbon-doped silicon oxides, various low-k dielectric materials known in the art, and combinations thereof. The existing pattern may be a final feature or an intermediate feature during the patterning process. In some embodiments, the substrate is planarized so that the existing pattern is not exposed and is accessible.

[0016] Next, in block (204), an optional adhesive is coated on the substrate or a part thereof. The optional adhesive may be coated on the substrate by any coating method known in the art. Suitable coating methods include, but are not limited to, vapor deposition, spin-on coating, and Langmuir-Blodgett monolayer coating. In one or more embodiments, the optional adhesive is coated on a target area. As used herein, "target area" or "target location" refers to an area on the substrate to accommodate a pattern.

[0017] The selective adhesive may preferentially adhere to one of the materials of the existing pattern. In one or more embodiments, the selective adhesive is attached to features of the existing pattern. FIG. 3b shows a substrate coated with a selective adhesive (303) that adheres to features of the existing pattern. The selective adhesive may adhere to features of the pattern at a ratio greater than 1:1. For example, without limitation, the selective adhesive may adhere features to the base layer to features of the pattern at a ratio ranging from 2:1 to 10:1.

[0018] In one or more embodiments, the selective adhesive is a chemical functional group that may be further functionalized. Exemplary selective adhesives include, but are not limited to, silanes, alkenes, alkynes, alcohols, silanols, amines, phosphines, phosphonic acids, and carboxylic acids. A specific selective adhesive coated on an existing pattern may vary depending on the specific chemical used in other components of the method (200). For example, various phosphonic acids and esters may react selectively or at least preferentially with natural or oxidized metal surfaces to form metal phosphonates that are preferentially or even selectively strongly bonded on the surface of a dielectric material (e.g., silicon oxide), and thus can be used as a selective adhesive coated on features within a base layer. A specific example of a suitable phosphonic acid is octadecylphosphonic acid (ODPA). Such surface coatings generally tend to be stable in many organic solvents but can be removed using weak aqueous acid and base solutions. Phosphines (e.g., organophosphines) may also be used optionally. Other common acids, such as sulfonic acid, sulfinic acid, and carboxylic acid, can also be used selectively.

[0019] Another example of a reaction that is selective or at least preferential toward metallic materials compared to dielectric materials, organic polymer materials, or other materials is various metal corrosion inhibitors, such as those used during chemical mechanical polishing to protect interconnected structures. Specific examples include benzotriazoles, other triazole functional groups, other suitable heterocyclic groups (e.g., heterocyclic-based corrosion inhibitors), and other metal corrosion inhibitors known in the art. In addition to triazole groups, other functional groups may be used to provide the desired attraction or reactivity toward the metal. Various metal chelating agents are also potentially suitable. Various amines (e.g., organic amines) are also potentially suitable.

[0020] Another example of a reaction that is selective or at least preferential toward metal materials compared to dielectric materials, organic polymer materials, or other materials is various thiols. As another example, 1,2,4-triazoles or similar aromatic heterocyclic compounds can be used to react selectively with metals compared to dielectrics and other specific materials. The selective adhesive may also contain functional groups capable of reacting with the functional groups of the polymer to bind the polymer to the surface. Various other metal-poisoning compounds known in the art may also be potentially used. These are merely a few exemplary examples, and it should be understood that other examples will be obvious to those skilled in the art and may benefit from the present disclosure. The selective adhesive may also comprise a polymer containing any of the aforementioned functional groups capable of selective attachment, wherein the polymer has functional groups along the main chain or as terminal groups and forms a layer of polymer chains attached to the target material.

[0021] In one or more embodiments, the selective adhesive comprises a solubility modifier. The composition of the solubility modifier may vary depending on the selective adhesive. As understood by those skilled in the art, any suitable solubility modifier may be included in the selective adhesive provided that the two materials do not react with each other. Generally, the solubility modifier may be any chemical that is activated by light or heat. For example, in some embodiments, the solubility modifier comprises an acid or a thermal acid generator (TAG). In the case of a TAG, the acid or generated acid must be sufficiently heated to increase the solubility of the first resist polymer in a specific developer applied by cleaving the bonds of the acid-degradable groups of the polymer in the surface area of ​​the first resist pattern. The acid or TAG is typically present in the composition in an amount of about 0.01 to 20 weight percent based on the total solids of the trimming composition.

[0022] Preferred acids are organic acids including non-aromatic and aromatic acids, each of which may optionally have fluorine substitution. Suitable organic acids are, for example: carboxylic acids such as formic acid, acetic acid, propionic acid, butyric acid, dichloroacetic acid, trichloroacetic acid, perfluoroacetic acid, perfluorooctanoic acid, oxalic acid, malonic acid, and succinic acid; hydroxyalkaline acids, such as citric acid; aromatic carboxylic acids such as benzoic acid, fluorobenzoic acid, hydroxybenzoic acid, and naphthoic acid; organic phosphoric acids such as dimethyl phosphate and dimethylphosphinic acid; and optionally fluorinated alkylsulfonic acids, including sulfonic acids such as methanesulfonic acid, trifluoromethanesulfonic acid, ethanesulfonic acid, 1-butanesulfonic acid, 1-perfluorobutanesulfonic acid, 1,1,2,2-tetrafluorobutane-1-sulfonic acid, 1,1,2,2-tetrafluoro-4-hydroxybutane-1-sulfonic acid, 1-pentanesulfonic acid, 1-hexanesulfonic acid, and 1-heptanesulfonic acid.

[0023] Exemplary fluorine-free aromatic acids include aromatic acids of general formula (I):

[0024]

[0025] Herein: R1 independently represents a substituted or unsubstituted C1-C20 alkyl group, a substituted or unsubstituted C5-C20 aryl group or a combination thereof, optionally containing one or more groups selected from carbonyl, carbonyloxy, sulfonamido, ether, thioether, a substituted or unsubstituted alkylene group, or a combination thereof; Z1 independently represents a group selected from carboxyl, hydroxy, nitro, cyano, C1 to C5 alkoxy, formyl, and sulfonic acid; a and b are independently integers from 0 to 5; and a+b is 5 or less.

[0026] An exemplary aromatic acid can have the general formula (II):

[0027]

[0028] Herein: R1 represents a substituted or unsubstituted C1-C20 alkyl group, a substituted or unsubstituted C5-C20 aryl group or a combination thereof, optionally containing one or more groups selected from carbonyl, carbonyloxy, sulfonamido, ether, thioether, a substituted or unsubstituted alkylene group, or a combination thereof; Z1 independently represents a group selected from carboxyl, hydroxy, nitro, cyano, C1 to C5 alkoxy, formyl, and sulfonic acid; a and b are independently integers from 0 to 5; and a+b is 5 or less.

[0029] An exemplary aromatic acid can have the general formula (II):

[0030]

[0031] Herein: R2 and R3 each independently represent a substituted or unsubstituted C1-C20 alkyl group, a substituted or unsubstituted C5-C16 aryl group or a combination thereof, optionally containing one or more groups selected from carbonyl, carbonyloxy, sulfonamido, ether, thioether, substituted or unsubstituted alkylene group, or a combination thereof; Z2 and Z3 each independently represent a group selected from carboxyl, hydroxy, nitro, cyano, C1 to C5 alkoxy, formyl, and sulfonic acid; c and d are independently integers from 0 to 4; c + d is 4 or less; e and f are independently integers from 0 to 3; and e + f is 3 or less.

[0032] Additional aromatic acids that may be included in the solubility modifier include general formula (III) or (IV):

[0033]

[0034] Herein: R4, R5 and R6 each independently represent a substituted or unsubstituted C1-C20 alkyl group, a substituted or unsubstituted C5-C12 aryl group, or a combination thereof, and optionally contain one or more groups selected from carbonyl, carbonyloxy, sulfonamido, ether, thioether, substituted or unsubstituted alkylene groups, or combinations thereof; Z4, Z5 and Z6 each independently represent a group selected from carboxyl, hydroxy, nitro, cyano, C1-C5 alkoxy, formyl, and sulfonic acid; g and h are independently integers from 0 to 4; g+h is 4 or less; i and j are independently integers from 0 to 2; i+j is 2 or less; k and 1 are independently integers from 0 to 3; k+l is 3 or less;

[0035]

[0036] Herein: R4, R5 and R6 each independently represent a substituted or unsubstituted C1-C20 alkyl group, a substituted or unsubstituted C5-C12 aryl group or a combination thereof, optionally containing one or more groups selected from carbonyl, carbonyloxy, sulfonamido, ether, thioether, a substituted or unsubstituted alkylene group, or a combination thereof; Z4, Z5 and Z6 each independently represent a group selected from carboxyl, hydroxy, nitro, cyano, C1 to C5 alkoxy, formyl, and sulfonic acid; g and h are independently integers from 0 to 4; g+h is 4 or less; i and j are independently integers from 0 to 1; i+j is 1 or less; k and l are independently integers from 0 to 4; k+l is 4 or less.

[0037] Suitable aromatic acids can alternatively be expressed by the general formula (V):

[0038]

[0039] Herein: R7 and R8 each independently represent a substituted or unsubstituted C1-C20 alkyl group, a substituted or unsubstituted C5-C14 aryl group or a combination thereof, optionally containing one or more groups selected from carboxyl, carbonyl, carbonyloxy, sulfonamido, ether, thioether, a substituted or unsubstituted alkylene group, or a combination thereof; Z7 and Z8 each independently represent a group selected from hydroxy, nitro, cyano, C1-C5 alkoxy, formyl, and sulfonic acid; m and n are independently integers from 0 to 5; m+n is 5 or less; o and p are independently integers from 0 to 4; o+p is 4 or less.

[0040] Additionally, exemplary aromatic acids may have the general formula (VI):

[0041]

[0042] Herein: X is O or S; R9 independently represents a substituted or unsubstituted C1-C20 alkyl group, a substituted or unsubstituted C5-C20 aryl group or a combination thereof, optionally containing one or more groups selected from carbonyl, carbonyloxy, sulfonamido, ether, thioether, a substituted or unsubstituted alkylene group, or a combination thereof; Z9 independently represents a group selected from carboxyl, hydroxy, nitro, cyano, C1 to C5 alkoxy, formyl, and sulfonic acid; q and r are independently integers from 0 to 3; and q + r is 3 or less.

[0043] In one or more embodiments, the acid is a free acid having fluorine substitution. Suitable free acids having fluorine substitution may be aromatic or non-aromatic. For example, free acids having fluorine substitution that can be used as solubility modifiers include, but are not limited to, the following:

[0044]

[0045]

[0046]

[0047] Suitable TAGs include those capable of producing non-polymer acids as described above. The TAG may be non-ionic or ionic. Suitable nonionic thermal acid generators are, for example, cyclohexyl trifluoromethyl sulfonate, methyl trifluoromethyl sulfonate, cyclohexyl p-toluenesulfonate, methyl p-toluenesulfonate, cyclohexyl 2,4,6-triisopropylbenzenesulfonate, nitrobenzyl ester, benzoin tosylate, 2-nitrobenzyl tosylate, tris(2,3-dibromopropyl)-1,3,5-triazine-2,4,6-trione, alkyl esters of organic sulfonic acids, p-toluenesulfonic acid, dodecylbenzenesulfonic acid, oxalic acid, phthalic acid, phosphoric acid, camphorsulfonic acid, 2,4,6-trimethylbenzenesulfonic acid, triisopropylnaphthalenesulfonic acid, 5-nitro-o-toluenesulfonic acid, 5-sulfosalicylic acid, 2,5-dimethylbenzenesulfonic acid, It includes 2-nitrobenzenesulfonic acid, 3-chlorobenzenesulfonic acid, 3-bromobenzenesulfonic acid, 2-fluorocaprylnaphthalenesulfonic acid, dodecylbenzenesulfonic acid, 1-naphthol-5-sulfonic acid, 2-methoxy-4-hydroxy-5-benzoylbenzenesulfonic acid, and salts thereof, and combinations thereof. Suitable ionic thermal acid generating agents include, for example, dodecylbenzenesulfonic acid triethylamine salt, dodecylbenzenedisulfonic acid triethylamine salt, p-toluenesulfonic acid-ammonium salt, p-toluenesulfonic acid-pyridinium salt, sulfonate salts, such as carbocyclic aryl and heteroaryl sulfonate salts, aliphatic sulfonate salts, and benzenesulfonate salts. Compounds that produce sulfonic acid upon activation are generally suitable. Preferred thermal acid generators include ammonium p-toluenesulfonate salts and heteroaryl sulfonate salts.

[0048] Preferably, the TAG is ionic, having a reaction scheme for the production of sulfonic acid as shown below:

[0049]

[0050] Here, RSO3 - is a TAG anion and X +is a TAG cation, preferably an organic cation. The cation may be a nitrogen-containing cation of general formula (I):

[0051]

[0052] This is a monoprotic form of nitrogen-containing base B. Suitable nitrogen-containing base B comprises, for example: optionally substituted amines such as ammonia, difluoromethylammonium, C1-20 alkyl amines, and C3-30 aryl amines; nitrogen-containing heteroaromatic bases such as pyridine or substituted pyridine (e.g., 3-fluoropyridine), pyrimidine, and pyrazine; nitrogen-containing heterocyclic groups such as oxazole, oxazolin, or thiazolin. The aforementioned nitrogen-containing base B may be optionally substituted with one or more groups selected from, for example, alkyl, aryl, halogen atoms (preferably fluorine), cyano, nitro, and alkoxy. Among these, base B is preferably a heteroaromatic base.

[0053] Base B generally has a pKa of 0 to 5.0, or 0 to 4.0, or 0 to 3.0, or 1.0 to 3.0. The term "pKa" as used herein is used according to the meaning recognized in the art, that is, pKa is the conjugate acid (BH) of the basic moiety (B) in an aqueous solution at approximately room temperature. - It is the negative logarithm of the dissociation constant (for base 10). In a specific embodiment, base B has a boiling point of less than about 170°C, or less than about 160°C, 150°C, 140°C, 130°C, 120°C, 110°C, 100°C, or 90°C.

[0054] Exemplary suitable nitrogen-containing cation (BH) + is NH4 + , CF2HNH2 + , CF3CH2NH3 + , (CH3)3NH + , (C2H5)3NH +, (CH3)2(C2H5)NH + and includes the following:

[0055]

[0056] Here, Y is alkyl, preferably methyl or ethyl.

[0057] In certain embodiments, the solubility converting agent may be an acid, such as trifluoromethanesulfonic acid, perfluoro-1-butanesulfonic acid, p-toluenesulfonic acid, 4-dodecylbenzenesulfonic acid, 2,4-dinitrobenzenesulfonic acid, and 2-trifluoromethylbenzenesulfonic acid; an acid generating agent, such as triphenylsulfonium antimonate, pyridinium perfluorobutanesulfonate, 3-fluoropyridinium perfluorobutanesulfonate, 4-t-butylphenyltetramethylenesulfonium perfluoro-1-butanesulfonate, 4-t-butylphenyltetramethylenesulfonium 2-trifluoromethylbenzenesulfonate, and 4-t-butylphenyltetramethylenesulfonium 4,4,5,5,6,6-hexafluorodihydro-4H-1,3,2-dithiazine 1,1,3,3-tetraoxide; or a combination thereof.

[0058] Alternatively, the solubility converting agent may comprise a base or a base generating agent. In such embodiments, suitable solubility converting agents include, but are not limited to, hydroxides, carboxylates, amines, imines, amides, and mixtures thereof. Specific examples of bases include ammonium carbonate, ammonium hydroxide, ammonium hydrogen phosphate, ammonium phosphate, tetramethylammonium carbonate, tetramethylammonium hydroxide, tetramethylammonium hydrogen phosphate, tetramethylammonium phosphate, tetraethylammonium carbonate, tetraethylammonium hydroxide, tetraethylammonium hydrogen phosphate, tetraethylammonium phosphate, and combinations thereof. Amines include aliphatic amines, alicyclic amines, aromatic amines, and heterocyclic amines. Amines may be primary, secondary, or tertiary amines. Amines may be monoamines, diamines, or polyamines. Suitable amines may include C1-30 organic amines, imines, or amides, or may be C1-30 quaternary ammonium salts of strong bases (e.g., hydroxides or alkoxides) or weak bases (e.g., carboxylates). Exemplary bases are amines such as tripropylamine, dodecylamine, tris(2-hydroxypropyl)amine, tetrakis(2-hydroxypropyl)ethylenediamine; It comprises aryl amines such as diphenylamine, triphenylamine, aminophenol, and 2-(4-aminophenyl)-2-(4-hydroxyphenyl)propane, troger bases, hindered amines such as diazabicyclodecene (DBU) or diazabicyclononene (DBN), amides such as tert-butyl 1,3-dihydroxy-2-(hydroxymethyl)propane-2-ylcarbamate and tert-butyl 4-hydroxypiperidin-1-carboxylate; or ionic quenchers comprising quaternary alkyl ammonium salts such as tetrabutylammonium hydroxide (TBAH) or tetrabutylammonium lactate. In other embodiments, the amine is a hydroxyamine.Examples of hydroxyamines include hydroxyamines having one or more hydroxyalkyl groups, such as hydroxymethyl, hydroxyethyl, and hydroxybutyl groups, each having 1 to about 8 carbon atoms, preferably 1 to about 5 carbon atoms. Specific examples of hydroxyamines include mono-, di-, and tri-ethanolamines, 3-amino-1-propanol, 2-amino-2-methyl-1-propanol, 2-amino-2-ethyl-1,3-propanediol, tris(hydroxymethyl)aminomethane, N-methylethanolamine, 2-diethylamino-2-methyl-1-propanol, and triethanolamine.

[0059] Suitable base generators may be thermal base generators. Thermal base generators typically form a base when heated above a first temperature of about 140°C or higher. Thermal base generators may include functional groups such as amides, sulfonamides, imides, imines, O-acyl oximes, benzoyloxycarbonyl derivatives, quaternary ammonium salts, nifedipine, carbamates, and combinations thereof. Exemplary thermobase generating agents include o-{(.beta.-(dimethylamino)ethyl)aminocarbonyl}benzoic acid, o-{(.gamma.-(dimethylamino)propyl)aminocarbonyl}benzoic acid, 2,5-bis{(.beta.-(dimethylamino)ethyl)aminocarbonyl}terephthalic acid, 2,5-bis{(.gamma.-(dimethylamino)propyl)aminocarbonyl}terephthalic acid, 2,4-bis{(.beta.-(dimethylamino)ethyl)aminocarbonyl}isophthalic acid, 2,4-bis{(.gamma.-(dimethylamino)propyl)aminocarbonyl}isophthalic acid, and combinations thereof.

[0060] Alternatively, in one or more embodiments, the solubility converting agent comprises a crosslinking agent. Suitable crosslinking agents that can be used as solubility converting agents include, but are not limited to, bis-epoxides such as bisphenol A diglycidyl ether, 2,5-bis[(2-oxyranylmethoxy)-methyl]-furan, 2,5-bis[(2-oxyranylmethoxy)methyl]-benzene, melamine, glycuryls such as tetramethoxymethyl glycoluryl and tetrabutoxymethyl glycoluryl, benzoguanamine-based materials such as benzoguanamine, hydroxymethylbenzoguanamine, methylated hydroxymethylbenzoguanamine, ethylated hydroxymethylbenzoguanamine, and crosslinking agents used to cure urea-based materials.

[0061] In one or more embodiments, the optional adhesive comprises a solvent. The solvent is typically selected from water, organic solvents, and mixtures thereof. In some embodiments, the solvent may comprise an organic solvent system comprising one or more organic solvents. The term “organic” means that the solvent system comprises more than 50 wt% of an organic solvent based on the total solvent of the solubility converting agent composition, and more typically comprises more than 90 wt%, more than 95 wt%, more than 99 wt%, or 100 wt% of an organic solvent based on the total solvent of the solubility converting agent composition. The solvent component is typically present in an amount of 90 to 99 wt% based on the solubility converting agent composition.

[0062] Organic solvents suitable for the selective adhesive composition include, for example: alkyl esters such as alkyl propionates such as n-butyl propionate, n-pentyl propionate, n-hexyl propionate and n-heptyl propionate, and alkyl butyrates such as n-butyl butyrate, isobutyl butyrate and isobutyl isobutyrate; ketones such as 2,5-dimethyl-4-hexanone and 2,6-dimethyl-4-heptanone; aliphatic hydrocarbons such as n-heptane, n-nonane, n-octane, n-decane, 2-methylheptane, 3-methylheptane, 3,3-dimethylhexane and 2,3,4-trimethylpentane, and fluorinated aliphatic hydrocarbons such as perfluoroheptane; Alcohols, for example, straight-chain, branched, or cyclic C4-C91 alcohols, for example, 1-butanol, 2-butanol, isobutyl alcohol, tert-butyl alcohol, 3-methyl-1-butanol, 1-pentanol, 2-pentanol, 4-methyl-2-pentanol, 1-hexanol, 1-heptanol, 1-octanol, 2-hexanol, 2-heptanol, 2-octanol, 3-hexanol, 3-heptanol, 3-octanol, and 4-octanol; 2,2,3,3,4,4-hexafluoro-1-butanol, 2,2,3,3,4,4,5,5-octafluoro-1-pentanol and 2,2,3,3,4,4,5,5,5,6,6-decafluoro-1-hexanol, and C5-C9 fluorinated diols such as 2,2,3,3,4,4-hexafluoro-1,5-pentanediol, 2,2,3,3,4,4,5,5-octafluoro-1,6-hexanediol and 2,2,3,3,4,4,5,5,6,6,7,7-dodecafluoro-1,8-octanediol; ethers such as isopentyl ether and propylene glycol monomethyl ether; Esters, for example, alkyl esters having a total number of carbon atoms of 4 to 10, for example, propylene glycol monomethyl ether acetate; alkyl propionates, for example, n-butyl propionate, n-pentyl propionate, n-hexyl propionate, and n-heptyl propionate; and alkyl butyrates, for example, n-butyl butyrate, isobutyl butyrate, and isobutyl isobutyrate; ketones, for example, 2,5-dimethyl-4-hexanone and 2,6-dimethyl-4-heptanone;and polyethers such as dipropylene glycol monomethyl ether and tripropylene glycol monomethyl ether; and a mixture containing one or more of these solvents.;

[0063] In some embodiments, after coating the substrate with a selective adhesive, the substrate is pretreated. The substrate may be pretreated to ensure adhesion of the selective adhesive to the surface of the feature. The pretreatment may be a soft bake performed for about 30 to 90 seconds at a temperature in the range of 50 to 150°C.

[0064] After attaching a selective adhesive material to a feature, any excess material can be removed. In this way, in one or more embodiments, a selective adhesive is applied to a substrate and selectively pretreated, and then the substrate is rinsed to remove unused material.

[0065] Next, in block (206) of the method (200), a first resist is deposited on a substrate. FIG. 3c shows a substrate coated with an optional adhesive (303) and a first resist (304). The first resist may be a photoresist. Generally, a photoresist is a chemically amplified photosensitive composition comprising a polymer, a photo-generating agent, and a solvent. In one or more embodiments, the first resist comprises a polymer. The polymer may be any standard polymer typically used in resist materials, and in particular may be a polymer having acid-unstable groups. For example, the polymer may be a polymer prepared from monomers including vinyl aromatic monomers such as styrene and p-hydroxystyrene, acrylates, methacrylates, norbornene, and combinations thereof. Monomers containing reactive functional groups may be present in the polymer in a protected form. For example, the -OH group of p-hydroxystyrene may be protected by a tert-butyloxycarbonyl protecting group. These protecting groups can alter the reactivity and solubility of the polymer contained in the first resist. As understood by those skilled in the art, various protecting groups may be used for this reason. Acid-unstable groups include, for example, tertiary alkyl ester groups, secondary or tertiary aryl ester groups, secondary or tertiary ester groups having a combination of alkyl and aryl groups, tertiary alkoxy groups, acetal groups, or ketal groups. Acid-unstable groups are also commonly referred to in the art as "acid-degradable groups," "acid-cleaving groups," "acid-cleaving protecting groups," "acid-unstable protecting groups," "acid-leaving groups," and "acid-sensitive groups."

[0066] The acid-unstable group that forms a carboxylic acid on the polymer upon decomposition is preferably of the formula -C(O)OC(R 1 )3 tertiary ester group or chemical formula -C(O)OC( R 2 )2OR 3 It is the acetal group of, and here: R 1 Each is independently linear C 1-20Alkyl, branched C 3-20 Alkyl, monocyclic, or polycyclic C 3-20 Cycloalkyl, linear C 2-20 Alkenyl, branched C 3-20 Alkenyl, monocyclic, or polycyclic C 3-20 Cycloalkenyl, monocyclic, or polycyclic C 6-20 Aryl, or monocyclic or polycyclic C 2-20 Heteroaryl, preferably linear C 1-6 Alkyl, branched C 3-6 Alkyl, or monocyclic or polycyclic C 3-10 They are cycloalkyl, each of which is substituted or unsubstituted, and each R 1 ... optionally includes one or more groups selected from —O—, —C(O)—, —C(O)—O—, or —S— as part of its structure, and any two R 1 The qi selectively forms a ring together; R 2 is independently hydrogen, fluorine, linear C 1-20 Alkyl, branched C 3-20 Alkyl, monocyclic, or polycyclic C 3-20 Cycloalkyl, linear C 2-20 Alkenyl, branched C 3-20 Alkenyl, monocyclic, or polycyclic C 3-20 Cycloalkenyl, monocyclic, or polycyclic C 6-20 Aryl, or monocyclic or polycyclic C 2-20 Heteroaryl, preferably hydrogen, linear C 1-6 Alkyl, branched C 3-6 Alkyl, or monocyclic or polycyclic C 3-10 They are cycloalkyl, each of which is substituted or unsubstituted, and each R 2 ... optionally includes one or more groups selected from ―O―, ―C(O)―, ―C(O)―O―, or ―S― as part of his structure, and R 2Gi selectively forms a ring together; and R 3 is linear C 1-20 Alkyl, branched C 3-20 Alkyl, monocyclic, or polycyclic C 3-20 Cycloalkyl, linear C 2-20 Alkenyl, branched C 3-20 Alkenyl, monocyclic, or polycyclic C 3-20 Cycloalkenyl, monocyclic, or polycyclic C 6-20 Aryl, or monocyclic or polycyclic C 2-20 Heteroaryl, preferably linear C 1-6 Alkyl, branched C 3-6 Alkyl, or monocyclic or polycyclic C 3-10 cycloalkyl, each of which is substituted or unsubstituted, and R 3 ... optionally includes one or more groups selected from —O—, —C(O)—, —C(O)—O—, or —S— as part of its structure, and 1 R 2 is R 3 These monomers are typically vinyl aromatic, (meth)acrylate, or norbornyl monomers that selectively form rings together. The total content of polymerization units containing acid-degradable groups that form carboxylic acid groups on the polymer is typically 10 to 100 mol%, more typically 10 to 90 mol%, or 30 to 70 mol% based on the total polymerization units of the polymer.

[0067] The polymer may additionally contain monomers containing acid-unstable groups when polymerized, and these groups decompose to form alcohol or fluoroalcohol groups on the polymer. Suitable such groups include, for example, the chemical formula ―COC(R 2 )2OR 3It includes an acetal group of -OC(O)O- or a carbonate ester group of the chemical formula -OC(O)O-, where R is as defined above. These monomers are generally vinyl aromatic, (meth)acrylate, or norbornyl monomers. The total content of polymerization units containing acid-degradable groups, which, when present in the polymer, decompose to form alcohol or fluoroalcohol groups on the polymer, is typically 10 to 90 mol%, more typically 30 to 70 mol%, based on the total polymerization units of the polymer.

[0068] A photoinitiator is a compound capable of generating acid upon irradiation with chemical light or radiation. The photoinitiator may be selected from known compounds capable of generating acid upon irradiation with chemical light or radiation, and may include photoinitiators for cationic photopolymerization, photoinitiators for radical photopolymerization, photodecolorizers for dyes, photochromic agents, microresists, etc., and mixtures thereof. Examples of photoinitiators include diazonium salts, phosphonium salts, sulfonium salts, iodosulfonates, imidosulfonates, oximesulfonates, diazodisulfones, disulfones, and o-nitrobenzyl sulfonates.

[0069] Suitable photogens include onium salts, e.g., triphenylsulfonium trifluoromethanesulfonate, (p-tert-butoxyphenyl)diphenylsulfonium trifluoromethanesulfonate, tris(p-tert-butoxyphenyl)sulfonium trifluoromethanesulfonate, triphenylsulfonium p-toluenesulfonate; di-t-butylphenyliodonium perfluorobutanesulfonate, and di-t-butylphenyliodonium camphorsulfonate. Non-ionic sulfonates and sulfonyl compounds are also photogeners, e.g., nitrobenzyl derivatives, e.g., 2-nitrobenzyl-p-toluenesulfonate, 2,6-dinitrobenzyl-p-toluenesulfonate, and 2,4-dinitrobenzyl-p-toluenesulfonate; Sulfonic acid esters, e.g., 1,2,3-tris(methanesulfonyloxy)benzene, 1,2,3-tris(trifluoromethanesulfonyloxy)benzene, and 1,2,3-tris(p-toluenesulfonyloxy)benzene; diazomethane derivatives, e.g., bis(benzenesulfonyl)diazomethane, bis(p-toluenesulfonyl)diazomethane; glyoxime derivatives, e.g., bis-O-(p-toluenesulfonyl)-α-dimethylglyoxime, and bis-O-(n-butanesulfonyl)-α-dimethylglyoxime; sulfonic acid ester derivatives of N-hydroxyimide compounds, e.g., N-hydroxysuccinimide methanesulfonic acid ester, N-hydroxysuccinimide trifluoromethanesulfonic acid ester; and is known to function as halogen-containing triazine compounds, e.g., 2-(4-methoxyphenyl)-4,6-bis(trichloromethyl)-1,3,5-triazine and 2-(4-methoxynaphthyl)-4,6-bis(trichloromethyl)-1,3,5-triazine. Suitable non-polymerizable photogenerators are further described in U.S. Patent No. 8,431,325 of Hashimoto et al. (column 37, lines 11–47, columns 41–91).Other suitable sulfonate PAGs include sulfonated esters and sulfonyloxy ketones, nitrobenzyl esters, s-triazine derivatives, benzoin tosylates, t-butylphenyl α-(p-toluenesulfonyloxy)-acetate, and t-butyl α-(p-toluenesulfonyloxy)-acetate, as described in U.S. Patent Nos. 4,189,323 and 8,431,325. Onium salt PAGs typically comprise anions having a sulfonate group or a non-sulfonate type group, such as a sulfonamidate group, a sulfonimidate group, a methide group, or a borate group.

[0070] The resist composition may optionally comprise a plurality of PAGs. The plurality of PAGs may be polymeric or non-polymeric, or may comprise both polymeric and non-polymeric PAGs. Preferably, each of the plurality of PAGs is non-polymeric. Preferably, when a plurality of PAGs are used, the first PAG comprises a sulfonate group on the anionic phase, and the second PAG comprises an anion without a sulfonate group, and such anion contains, for example, a sulfonamidate group, a sulfonimidate group, a methide group, or a borate group as described above. In some embodiments, the first resist has a composition similar to a positive tone development (PTD) resist. In such embodiments, the first relief pattern may comprise a polymer prepared from the aforementioned monomers, wherein any monomer containing a reactive functional group is protected. Thus, the PTD first resist may be organically soluble.

[0071] In another embodiment where the solubility modifier is a crosslinking agent, the first resist is a negative resist. In this embodiment, the first resist may comprise a polymer prepared from the aforementioned monomer, wherein any monomer containing a reactive functional group is not protected. Suitable reactive functional groups include, but are not limited to, alcohols, carboxylic acids, and amines. Upon exposure to the crosslinking agent, the polymer is crosslinked and becomes insoluble in the developer. Then, the uncrosslinked regions can be removed using a suitable developer.

[0072] In one or more embodiments, the first resist is a negative resist. In such embodiments, the first relief pattern may comprise a polymer prepared from the aforementioned monomer, wherein any monomer containing a reactive functional group is not protected. Thus, the first resist may be soluble in an organic solvent or an aqueous base. The tone of the resist (i.e., positive or negative) may affect the final pattern placement. For example, if the resist is similar to a PTD photoresist and the selective adhesive contains an acid, the resist polymer on the feature will be deprotected and soluble in an aqueous base (e.g., TMAH), while the resist on the substrate will remain soluble in an organic solvent. If the resist is similar to a negative photoresist and the selective adhesive contains a crosslinking agent, the resist polymer on the feature will be crosslinked and insoluble, while the resist on the substrate will remain soluble.

[0073] In one or more embodiments, the first resist is laminated on a substrate to have a thickness of about 300 Å to about 3000 Å.

[0074] Next, in block (208) of method (200), the solubility-converting agent is activated. In an embodiment where the solubility-converting agent is an acid, an acid-generating agent, a base, or a base-generating agent, the activation of the solubility-converting agent comprises diffusing the solubility-converting agent into the first resist to provide a solubility-converted region of the first resist. The solubility-converted region of the first resist may be indicated by the preferential attachment of an optional adhesive. For example, an optional adhesive that preferentially attaches to features of an existing pattern, such as in the optional patterning self-alignment of method (200), may provide a solubility-converted region of the first resist over the features. In one or more embodiments, the solubility-converted region of the first resist extends vertically from the surface of the optional adhesive coated on the features to the surface of the first resist. In one or more embodiments, the solubility-converted region extends in an inclined direction. When the solubility-converted region extends in an inclined direction, it may be desirable to prevent the features from merging with each other. To achieve this, the feature thickness can be controlled to become sufficiently thin.

[0075] By performing baking, the solubility converting agent is diffused into the first resist. Baking can be performed using a hot plate or an oven. The baking temperature and time may vary depending on the identity of the second resist and the desired amount of solubility converting agent diffused into the second resist. Suitable conditions for baking may include a temperature in the range of about 50°C to about 160°C and a time in the range of about 30 seconds to about 90 seconds.

[0076] The solubility conversion region of the first resist may be indicated by the preferential attachment of a selective adhesive. For example, when the selective adhesive is preferentially attached to a feature of an existing pattern, such as in selective patterning self-alignment as in method (200), the solubility conversion region of the first resist may be on the feature. In one or more embodiments, the solubility conversion region of the first resist may extend perpendicularly to the surface of the first resist layer.

[0077] In an embodiment where the solubility converting agent is a crosslinking agent, activation of the solubility converting agent includes initiating polymerization of the crosslinking agent into a first resist. Activation of the crosslinking agent may provide a crosslinked region of the first resist. The crosslinked region of the first resist may be indicated by the preferential attachment of a selective adhesive. For example, when the selective adhesive is preferentially attached to a feature of an existing pattern, such as in selective patterning self-alignment, the crosslinked region of the first resist may be located on the feature.

[0078] Finally, in block (210) of the method (200), the first resist is developed using a first developer. The first developer may be any developer commonly used in the field. The composition of the first developer may vary depending on the solubility characteristics of the first resist. For example, if the first resist is a positive tone developing resist, the specific developer may be a base such as tetramethylammonium hydroxide. On the other hand, if the first resist is a negative tone developing resist, the specific developer may be a non-polar organic solvent such as n-butyl acetate or 2-heptanone. In one or more embodiments, the solubility-changed or cross-linked regions are insoluble in the first developer. Thus, after developing the first resist, the solubility-changed or cross-linked regions of the first resist may remain on the substrate. In this way, the method (200) can provide a substrate including a pattern of a solubility conversion first resist (305) as shown in FIG. 3d, wherein the solubility conversion first resist is located immediately above a feature (302) of an existing pattern.

[0079] Alternatively, in one or more embodiments, the solubility conversion region becomes soluble in the first developer. In such an embodiment, after developing the first resist, the solubility conversion region of the first resist is removed from the substrate. A coated substrate according to such an embodiment is shown in FIG. 3e. In FIG. 3e, the substrate includes a pattern of the first resist (306) offset from the features (302) coated on the selective adhesive (303). This pattern may be referred to as a semi-selective pattern because the features of the resist remain on a base layer not coated with the selective adhesive.

[0080] As mentioned above, in one or more embodiments, the method includes the step of selectively forming an alternative resist pattern for a feature within a base layer. Such a method, such as method (200), can be considered as selective pattern formation because it forms a first relief pattern according to the placement of the selective adhesive. However, a method of selectively forming an alternative pattern or a first relief for an existing feature pattern can be considered as selective alignment prevention because the two patterns are not aligned. A method (400) of selectively forming an anti-aligned pattern (e.g., the pattern shown in FIG. 1b) according to the present disclosure is illustrated in FIG. 4 and discussed with reference thereto. Schematic depictions of a coated substrate at various points during the method are shown in FIG. 5a through 5d.

[0081] In method (400), an existing pattern in block (402) is provided on a substrate. A coated substrate having the existing pattern is shown in FIG. 5a. In FIG. 5a, the existing pattern may include a feature (502) within a base layer (501). The feature and the base layer are as previously described with reference to method (200).

[0082] Next, in block (404) of method (400), the substrate is coated with an optional adhesive. In one or more embodiments, the optional adhesive is coated over the entire substrate anticipating the target area (i.e., the optional adhesive is coated over the entire base layer excluding the features). As previously described, the optional adhesive may preferentially adhere to one of the materials of the existing pattern. In one or more embodiments of method (400), the optional adhesive is adhered to the base layer of the existing pattern. FIG. 5b shows a substrate comprising an optional adhesive (503) that coats the first layer rather than the features of the existing pattern. The optional adhesive may be adhered to the features of the pattern at a ratio greater than 1:1. For example, without limitation, the optional adhesive may be adhered to the base layer of the existing pattern at a feature-to-base layer ratio ranging from 1:2 to 1:10.

[0083] In one or more embodiments, the selective adhesive is a chemical functional group that may be further functionalized. Exemplary selective adhesives that are selective to dielectric materials rather than metals include, but are not limited to, silanes and alcohols. A specific selective adhesive coated on an existing pattern may vary depending on a specific chemical used in other components of the method (200). For example, aminosilanes, halosilanes (e.g., chlorosilanes, fluorosilanes, etc.), and alkoxysilanes (e.g., methoxysilanes, ethoxysilanes, and other alkoxysilanes) may react selectively or at least preferentially with hydroxyl groups on the surface of the dielectric material compared to the metal material. Specific examples of suitable silanes include, but are not limited to, trichlorooctadecylsilane, octadecylchlorosilane, diethylaminotrimethylsilane, bis(dimethylamino)dimethylsilane, methoxysilane, ethoxysilane, and other similar silanes, and combinations thereof. The reaction products of such reactions can be used to selectively cover the exposed surfaces of dielectric materials. In metallic materials, if a specific small amount of reaction generally occurs, it can be removed, for example, by washing with water. Silanes may contain one or more other groups, e.g., straight alkane chains, branched alkane chains, other straight or branched organic chains, benzyl groups, or other organic groups, or various other known functional groups, to alter the chemical properties of the silane and obtain desired chemical properties. Compounds containing hydroxyl groups, such as alcohols and catechol, are also known to react with the hydroxylation groups of dielectric materials. As another example, difunctional, trifunctional, polyfunctional electrophiles, or combinations thereof, can react with the hydroxyl groups of a material (e.g., ILD), and then the resulting activation reaction product can be reacted with the functional groups of the polymer.The selective adhesive may also comprise a polymer containing any of the aforementioned functional groups capable of selective attachment, wherein the polymer has functional groups along the main chain or as terminal groups and forms a layer of polymer chains attached to the target material. Various other selective adhesives known in the art may also potentially be used. These are merely a few exemplary examples, and it should be understood that other examples will be obvious to those skilled in the art and may benefit from the present disclosure.

[0084] In one or more embodiments, the optional adhesive comprises a solubility converter. The solubility converter may be a solubility converter as previously described with reference to method (200).

[0085] In some embodiments, after coating the substrate with a selective adhesive, the substrate is pretreated. The pretreatment may be performed by baking at 50 to 150°C for about 30 to 90 minutes.

[0086] In block (406) of method (400), a first resist is deposited on a substrate. A substrate coated with the first resist (504) is shown in FIG. 5C. In one or more embodiments, the first resist is as previously described with reference to method (200). In one or more embodiments, the first resist is laminated on the substrate to have a thickness of about 300 Å to about 3000 Å.

[0087] In block (408) of the method (400), a solubility converting agent is activated. In an embodiment where the solubility converting agent is an acid, an acid generator, a base, or a base generator, the activation of the solubility converting agent comprises diffusing the solubility converting agent into the first resist as described above to provide a solubility-converted region of the first resist.

[0088] The solubility conversion region of the first resist may be indicated by the preferential attachment of a selective adhesive. For example, when the selective adhesive is preferentially attached to the base layer of an existing pattern, as in semi-selective pattern self-alignment such as method (400), the solubility conversion region of the first resist may be on the base layer. In one or more embodiments, the solubility conversion region of the first resist may extend perpendicularly to the surface of the first resist layer.

[0089] In an embodiment where the solubility converting agent is a crosslinking agent, activation of the solubility converting agent includes initiating polymerization of the crosslinking agent into the first resist. Activation of the crosslinking agent may provide a crosslinked region of the first resist. The crosslinked region of the first resist may be indicated by the preferential attachment of a selective adhesive. For example, when the selective adhesive is preferentially attached to the base layer of an existing pattern, such as in semi-selective pattern self-alignment, the crosslinked region of the first resist may be located on the base layer. The crosslinked region of the first resist may extend vertically from the base layer to the surface of the first resist.

[0090] Finally, in method (400), the first resist is developed in block (410). The first resist may be developed using a first developer. The first developer may be selected according to the solubility characteristics of the first resist. In one or more embodiments, the solubility conversion or crosslinked regions of the first resist are insoluble in the first developer. Therefore, after developing the first resist, the solubility conversion or crosslinked regions of the first resist may remain on the substrate. Thus, method (400) may provide a substrate having a pattern of solubility conversion first resist (505) as shown in FIG. 5d, wherein the solubility conversion first resist is offset from the features (502) of the existing pattern.

[0091] In one or more embodiments, the semi-selective pattern self-alignment process may be modified so that the solubility conversion region dissolves in the first developer. In this alternative embodiment, after development, the remaining modified first resist is positioned on top of the features of the existing pattern, as in selective pattern self-alignment.

[0092] Similarly, in one or more embodiments, the selective pattern self-alignment process may be modified so that the solubility conversion region dissolves in the first developer. In this alternative embodiment, after development, the remaining modified first resist is offset from the features of the existing pattern, such as in semi-selective pattern self-alignment.

[0093] In one or more embodiments, the method disclosed herein may be used in a dual patterning feature on / beside an existing pattern. To achieve dual patterning, such a method may implement two optional pattern self-alignment processes, two semi-optional pattern self-alignment processes, or one optional pattern self-alignment process and one semi-optional pattern self-alignment process.

[0094] In an alternative embodiment, the feature is coated with a first selective adhesive containing a first solubility converting agent, and the base layer is coated with a second selective adhesive containing a second solubility converting agent. In some embodiments, the first solubility converting agent comprises an acid or an acid-generating agent, and the second solubility converting agent comprises a base or a base-generating agent. Then, a resist is deposited on the substrate and the solubility converting agents are simultaneously activated. The first solubility converting agent diffuses from the top of the feature, and the second solubility converting agent diffuses from the top of the base layer. At the interface of the diffusion front, the solubility converting agents may interact with each other to prevent solubility conversion of the resist in a lateral region outside the vertical plane perpendicular to the substrate, located at the interface between the feature and the exposed base layer. This helps to limit solubility conversion for the resist region over the feature, thereby limiting lateral growth of the opening and creating an approximately straight edge rather than a slanted profile.

[0095] Although only a few exemplary embodiments have been described in detail above, those skilled in the art will readily understand that many modifications are possible from the exemplary embodiments without substantially departing from the invention. Accordingly, all such modifications are intended to be included within the scope of the disclosure as defined in the following claims.

Claims

Claim 1 A microfabrication method comprising: a step of providing a substrate having an existing pattern, wherein the existing pattern includes features formed within a base layer such that the top surface of the substrate has uncovered features and the base layer is not covered; a step of depositing a selective adhesive on the substrate, wherein the selective adhesive includes a solubility converter; a step of depositing a first resist on the substrate; a step of activating the solubility converter so that a portion of the first resist becomes insoluble in a first developer; and a step of developing the first resist using a first developer so that a portion of the first resist insoluble in the first developer remains. Claim 2 A method according to claim 1, wherein the selective adhesive adheres more to the surface of the feature than to the surface of the base layer. Claim 3 A method according to claim 1 or 2, wherein the optional adhesive comprises phosphonic acid, phosphonate ester, phosphine, sulfonic acid, sulfinic acid, carboxylic acid, triazole, thiol, or a combination thereof. Claim 4 A method according to claim 1 or 2, wherein a portion of the first resist insoluble in the first developer is on the feature. Claim 5 A method according to claim 1, wherein the selective adhesive adheres more to the surface of the base layer than to the surface of the feature. Claim 6 A method according to claim 1 or 5, wherein the optional adhesive comprises a silane, an alcohol, or a combination thereof. Claim 7 A method according to claim 1 or 5, wherein a portion of the first resist insoluble in the first developer is on the base layer. Claim 8 A method according to any one of claims 1, 2 and 5, wherein the solubility converting agent comprises an acid generating agent. Claim 9 In paragraph 8, the acid generating agent is fluorine-free. Claim 10 A method according to claim 8, wherein the acid generating agent is selected from the group consisting of triphenylsulfonium antimonate, pyridinium perfluorobutanesulfonate, 3-fluoropyridinium perfluorobutanesulfonate, 4-t-butylphenyltetramethylenesulfonium perfluoro-1-butanesulfonate, 4-t-butylphenyltetramethylenesulfonium 2-trifluoromethylbenzenesulfonate, 4-t-butylphenyltetramethylenesulfonium 4,4,5,5,6,6-hexafluorodihydro-4H-1,3,2-dithiazine 1,1,3,3-tetraoxide, and combinations thereof. Claim 11 A method according to any one of claims 1, 2 and 5, wherein the solubility converting agent comprises an acid. Claim 12 In paragraph 11, the acid is fluorine-free. Claim 13 The method according to claim 11, wherein the acid is selected from the group consisting of trifluoromethanesulfonic acid, perfluoro-1-butanesulfonic acid, p-toluenesulfonic acid, 4-dodecylbenzenesulfonic acid, 2,4-dinitrobenzenesulfonic acid, 2-trifluoromethylbenzenesulfonic acid, and combinations thereof. Claim 14 A method according to any one of claims 1, 2 and 5, further comprising the step of pre-treating the substrate before depositing the first resist on the substrate. Claim 15 A microfabrication method comprising the following: providing a substrate having an existing pattern, wherein the existing pattern includes features formed within a base layer such that the top surface of the substrate has uncovered features and the base layer is not covered; depositing a selective adhesive on the substrate, wherein the selective adhesive includes a solubility converter; depositing a first resist on the substrate; activating the solubility converter so that a portion of the first resist becomes soluble in a first developer; and developing the first resist using a first developer so that a portion of the first resist soluble in the first developer is removed. Claim 16 In paragraph 15, a method in which the selective adhesive adheres more to the surface of the feature than to the surface of the base layer. Claim 17 A method according to claim 15 or 16, wherein a portion of the first resist insoluble in the first developer is on the feature. Claim 18 A method according to claim 15 or 16, wherein the optional adhesive comprises phosphonic acid, phosphonate ester, phosphine, sulfonic acid, sulfinic acid, carboxylic acid, triazole, thiol, or a combination thereof. Claim 19 A method according to claim 15 or 16, wherein the solubility converting agent comprises an acid generating agent. Claim 20 In paragraph 19, the acid-generating agent is fluorine-free. Claim 21 The method of claim 19, wherein the acid generating agent is selected from the group consisting of triphenylsulfonium antimonate, pyridinium perfluorobutanesulfonate, 3-fluoropyridinium perfluorobutanesulfonate, 4-t-butylphenyltetramethylenesulfonium perfluoro-1-butanesulfonate, 4-t-butylphenyltetramethylenesulfonium 2-trifluoromethylbenzenesulfonate, 4-t-butylphenyltetramethylenesulfonium 4,4,5,5,6,6-hexafluorodihydro-4H-1,3,2-dithiazine 1,1,3,3-tetraoxide, and combinations thereof. Claim 22 In paragraph 15 or 16, the method wherein the solubility converting agent comprises an acid. Claim 23 In paragraph 22, the acid is fluorine-free. Claim 24 A method according to claim 22, wherein the acid is selected from the group consisting of trifluoromethanesulfonic acid, perfluoro-1-butanesulfonic acid, p-toluenesulfonic acid, 4-dodecylbenzenesulfonic acid, 2,4-dinitrobenzenesulfonic acid, 2-trifluoromethylbenzenesulfonic acid, and combinations thereof. Claim 25 A method according to claim 15 or 16, further comprising the step of pre-treating the substrate before depositing the first resist on the substrate. Claim 26 A microfabrication method comprising: a step of providing a substrate having an existing pattern, wherein the existing pattern includes features formed within a base layer such that the top surface of the substrate has features that are not covered and the base layer is not covered; a step of depositing a first selective adhesive on the substrate, wherein the first selective adhesive comprises a first solubility converter and the first selective adhesive is attached more to the surface of the feature than to the surface of the base layer; a step of depositing a second selective adhesive on the substrate, wherein the second selective adhesive comprises a second solubility converter and the second selective adhesive is attached more to the surface of the base layer than to the surface of the feature; a step of depositing a first resist on the substrate; a step of activating the first and second solubility converters such that a portion of the first resist becomes insoluble in a first developer; and a step of developing the first resist using a first developer such that a portion of the first resist insoluble in the first developer remains. Claim 27 A method according to claim 26, wherein the first solubility converting agent comprises an acid or an acid generating agent, and the second solubility converting agent comprises a base or a base generating agent.

Images