Organic metal radiation patternable coatings with low defectivity and corresponding methods

Abstract

In the context of forming radiation-patternable structures, particularly for EUV patterning, a wafer structure is described that includes a substrate having a smooth top surface and a radiation-sensitive organometallic coating, the radiation-sensitive organometallic coating having an average thickness of no more than 100 nm and having no more than about 1 defect per square centimeter when evaluated for defects greater than 48 nm in size, excluding a 3 mm edge. A corresponding method for forming a low-defect coating includes spin coating a purified radiation-sensitive organometallic resist solution onto a wafer to form a coated wafer using a spin coater system, the spin coater system including a delivery line and a delivery nozzle connected to the delivery line, and drying the coated wafer to form a radiation-sensitive organometallic coating having no more than about 1 defect per square centimeter when evaluated for defects greater than 48 nm in size, excluding a 3 mm edge.

Description

Technical Field

[0001] The present invention relates to monoalkyltin compositions, specifically monoalkyltin trialkoxides and monoalkyltin triamines that have been coated to form radiation patternable coatings having low defect counts. The precursor compositions can be treated to have low metal contamination and / or low particulate contamination. Background Art

[0002] Solutions of organometallic compounds form coatings containing radiation-sensitive metal-carbon bonds that can be used to pattern structures photolithographically. The processing of semiconductor materials and devices with ever-shrinking dimensions has created a need for high-purity solutions with low particle counts to mitigate contamination problems, minimize pattern defects, and realize the advantages of organometallic photoresists. The processing and performance of semiconductor materials for microelectronic applications can be sensitive to metal contaminants. In order to produce microelectronic products using photolithographic techniques, proper control of metal contaminants can reduce waste caused by failure to meet product specifications. Summary of the invention

[0003] In a first aspect, the present invention is directed to a wafer structure comprising a substrate having a smooth top surface and a radiation-sensitive organic metal coating having an average thickness of no more than 100 nm and having no more than about 1 defect per square centimeter when evaluated for defects greater than 48 nm in size, excluding a 3 mm edge.

[0004] In another aspect, the present invention relates to a method for forming a low defect coating, the method comprising spin coating a purified radiation-sensitive organometallic resist solution onto a wafer to form a coated wafer using a spin coater system, and drying the coated wafer to form a radiation-sensitive organometallic coating, wherein the spin coater system comprises a delivery line and a delivery nozzle connected to the delivery line, the radiation-sensitive organometallic coating having no more than about 1 defect per square centimeter when evaluated for defects greater than 48 nm in size, excluding 3 mm edges. Typically, the organometallic resist solution has a tin concentration of about 0.01 M to about 0.25 M, and has been filtered to contain no more than about 10 particles / mL when the particle size is at least about 70 nm, and the organometallic resist solution is delivered from a container connected to the delivery line, wherein the particulate impurities are measured in a closed filtration system under conditions substantially free of bubbles. In addition, the delivery of the organometallic resist solution can be performed under conditions limiting water contact between the container and the delivery nozzle.

[0005] In another aspect, the present invention relates to a method for forming an organometallic resist composition having low particulate contamination, the method comprising:

[0006] circulating an organometallic resist composition from a first mixing vessel through a first filter on a first filtration loop using an impeller pump to remove particulate contaminants to form a first filtered composition, the first mixing vessel having an inlet and an outlet;

[0007] directing the first filtration composition to a second filtration loop, the second filtration loop comprising a second mixing vessel;

[0008] using an impeller pump, circulating the first filter composition in a second filter loop through a second filter to remove particulate contaminants to form a second filter composition until the second filter composition reaches a purification parameter, the purification parameter comprising a particulate concentration below a design level, a volume transfer through the filter above a design level, or a combination thereof;

[0009] wherein the particle concentration is measured in-line in a closed system substantially free of air bubbles;

[0010] placing the filtered organometallic resist composition into a container within the clean room, wherein flow is directed from the branch valve along the second filter loop; and

[0011] The container within the clean room is sealed.

[0012] In another aspect, the present invention relates to an apparatus for removing particles from an organometallic resist composition, the apparatus comprising:

[0013] a. a first flow circuit, the first flow circuit comprising a mixing container having an inlet and an outlet, a first impeller pump, a first filter and a conduit for connecting the elements in a closed loop, the first flow circuit being configured for the first impeller pump to direct flow through the first filter along a path from the inlet to the outlet to remove particulate contaminants;

[0014] b. a second flow circuit comprising a mixing vessel having an inlet and an outlet, a second impeller pump, a second filter, and conduits for connecting the elements in a closed loop, the second flow circuit being configured for the second impeller pump to direct flow through the second filter along a path from the inlet to the outlet to remove particulate contaminants;

[0015] c. a connecting line comprising a valve and a flow conduit, the connecting line being configured to provide flow between the first flow circuit and the second flow circuit;

[0016] d. a distribution line connected to the second flow circuit, the distribution line comprising a valve and a flow conduit, the distribution line being configured to distribute the filtered resist composition from the second flow circuit within the clean room.

[0017] In other aspects, the invention is directed to a composition comprising a solvent and an organotin composition having a tin concentration of about 0.005 M to about 0.5 M and no more than about 4 particles / mL when the particle size is at least about 70 nm, measured in a closed system substantially free of bubbles. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a schematic diagram of a filtration apparatus suitable for removing fine particles from an organotin composition.

[0019] Figure 2 is a schematic diagram of the dual-track resist purification system.

[0020] Figure 3 is a schematic diagram of a wafer orbital spin coating system.

[0021] Figure 4 is a schematic diagram of a filtration system of a specific example. DETAILED DESCRIPTION

[0022] By using a spin coating for providing high resolution patterning within a specific specification and a high yield wafer, a radiation patternable organic metal coating with a very low number of defects is formed. The defect reduction in the resist composition coating makes it less likely to produce defective parts formed by patterning, which generally involves various combinations of patterning, developing, etching, deposition, etc. This work is based on the processing of reducing the particles in the precursor solution by introducing process control along the production pipeline. Specifically, the improved particle removal during the preparation and storage of the resist can be converted into fewer defects in the subsequent coating formation. In addition, during the coating process, the coating pipeline should be appropriately primed for resist delivery, and the resist delivery should be controlled to reduce the water migrating to the resist during transportation in the coating equipment. Particularly desirable radiation patternable organic metal resists are based on organic tin oxide hydroxide chemistry, and the coating composition can be a hydrolyzable composition of a coating of an oxide hydroxide material for patterning. It has been found that tin-based resists are very effective for EUV patterning with high contrast to be able to form very fine features. Extensive developments around these materials have made it possible to produce commercially viable resist materials.

[0023] Semiconductor manufacturing typically requires the execution of many sequential and repetitive processes to form specific structures and features on a substrate. Defects in structures and features formed early in the manufacturing process may be carried over to subsequent processes. Therefore, it is desirable to reduce the formation of defects at any point in the processing of a semiconductor device, thereby increasing the fidelity of the desired features and thus improving device yield.

[0024] Photoresists play an indispensable role in the manufacture of semiconductor devices. In order to ultimately form the desired features and structures on the substrate, the photolithography process is performed as follows: first, an initial pattern is formed in the photoresist layer, and then the initial pattern is transferred to the substrate by repeated deposition and etching processes. The entire process is repeated until the desired device structure is obtained. Therefore, it is expected that the deposited layer of photoresist is smooth, continuous and uniform, that is, has few defects.

[0025] Similarly, it is desirable for the photoresist to faithfully reproduce the selected radiation pattern with as few defects as possible. For example, if defects are present in the deposited photoresist coating, the spatial pattern of the radiation may not be faithfully transferred into a latent image having the desired spatial distribution of different solubilities to reproduce the desired physical pattern in the resist. If such defects are present in the initial resist pattern, the defects will be transferred as defects into the intermediate device or the final device, thereby resulting in a reduction in the overall device yield.

[0026] Additionally, for patterns of lines and spaces, some examples of patterning defect modes are micro-bridging, where two adjacent features are unintentionally connected by material that should have been removed, and line breaks, where material is missing from the line. Patterning defects can be caused by a variety of different sources, but it is important from a materials standpoint to ensure that the photoresist can reproduce the intended pattern with high fidelity. If such defects are present in the initial resist pattern, such defects will transfer as defects into the intermediate or final device, thus resulting in reduced overall device yield.

[0027] In order to form integrated circuits and other devices based on wafer patterning technology, components are usually patterned on a grid. After processing, the patterned wafer is cut to form individual components. Due to the short wavelength, EUV processing allows the formation of particularly small features, which is desirable for fitting more components or more features of components onto a small footprint. Wafers and / or components are usually tested to identify any components that do not meet specifications. As described above, defects that affect component performance may be caused by the coating process or by the patterning process itself. These two sources of defects can be considered as potential relatively independent sources that do not meet component specifications. Important efforts to reduce patterning defects are described in the published U.S. patent application 2020 / 0326627 entitled "Organometallic Photoresist Developer Compositions and Processing Methods" by Jiang et al., which is incorporated herein by reference. The teachings of this article can effectively reduce coating defects.

[0028] Particulates and other insoluble materials are common contaminants in photoresist solutions, and resist solutions are often filtered to reduce the number of detectable particulates in the solution, as described in published U.S. Patent Application 2020-0239498 (hereinafter referred to as the '498 application), entitled "Monoalkyl Tin Trialkoxides and / or Monoalkyl Tin Triamides With [Low] Particulate Contamination and Corresponding Methods" by Clark et al., which is incorporated herein by reference. Other insoluble materials (i.e., defects) may be formed during the processing or deposition of the photoresist and appear as detectable defects on the wafer. For example, organometallic and metal oxide photoresists may undergo undesirable hydrolysis and / or condensation reactions, which may result in particulate formation. In other examples, material may be detached from surfaces such as filter membranes, pipes, container walls, etc. that contact the photoresist to form particulates within the solution. Other forms of particle generation may occur during processing of the material due to particle shedding effects caused by agitation or abrasive contact between two objects, where particles from external materials may land on or in the resist solution.

[0029] Although not wishing to be limited by theory, during the processing period from the container of the resist to the coating formation, it should be believed that the water migration entering the resist in the closed flow may cause the increase of defect formation. Therefore, although water may be useful for hydrolyzing the resist composition to form a radiation patternable coating, premature water interaction may cause defect formation during the distribution nozzle transferred to the coater. Therefore, it may be desirable to prevent water from migrating into the fluid transport system for conveying the resist in the coater pipeline. For example, the mode of limiting water migration includes replacing or sealing a water-permeable polymer pipeline with a more water-resistant material (such as, corrosion-resistant metal or other materials). Additionally or alternatively, a smaller virtual flow can be continued in the coater pipeline to avoid the resist staying in a fixed position in the delivery line. In an additional or optional embodiment, a filter can be placed along the resist delivery track, such as a shorter distance with a spin coater nozzle. Immediately filtering the resist before spin coating can cause the resulting coated wafer to have a very low defect value. Wafer defects are measured using optical measurements usually. About 90% of the equipment used to evaluate the quality of unpatterned wafers for integrated circuit production is sold by KLA-Tencor (Surfscan SP5 and SP7), while other systems are sold by Hitachi-Hightech (Wafer Surface Inspection System LS) and Applied Materials (SEMVISION TM G7) for sale.

[0030] While organometallic resists have provided significant advances in EUV patterning, providing better exploitation of fine patterning capabilities, the significant change in chemistry relative to conventional photoresists has introduced some challenges to achieving full commercial deployment. The advances described herein reduce defectivity, which in turn improves wafer yield within wafer quality specifications.

[0031] The resist process can be further improved to reduce particle counts and correspondingly improve wafer quality based on lower measured defect rates. Lower particle contamination counts can be obtained at least in part by optimizing the process described in the '498 application. Further improvements can be obtained while providing scaling convenience by using a dual loop filtration system in which the loops are arranged in sequence (as illustrated below). The processing structure with two filtration loops presents an improvement over the embodiment proposed in the '498 application. Therefore, the organometallic resist entering the second loop is already substantially purified, which allows improved particle removal to be achieved in the second loop before the resist is placed in the container.

[0032] Particle measurements obtained in a closed process system prior to placement in a container are directly comparable and are generally considered to be free of bubbles and other disturbances, which can make the readings measured by scattering essentially equal to particles. Once the resist is placed in the container, subsequent particle measurements taken on the liquid removed from the container will detect significantly more particles. The results show that these increased particle measurements are generally substantially due to bubbles, etc., because bubbles are not associated with defect formation in the coating on the wafer. However, after placement in the container, other sources of particles may exist, such as particle formation due to contact with the container, particles shed from the container cover or other external sources, and / or particle nucleation caused by storage.

[0033] Organometallic photoresists (such as organotin oxide hydroxides) have been shown to have excellent properties as photoresists for photolithographic photopatterning. Suitable organometallic photoresists include organotin materials described in the following documents: U.S. Patent No. 9,310,684B2 entitled "Organometallic Solution Based High Resolution Patterning Compositions" by Meyers et al., published U.S. Patent Application No. 2016 / 0116839A1 entitled "Organometallic Solution Based High Resolution Patterning Compositions and Corresponding Methods" by Meyers et al., and U.S. Patent No. 10,228,618B2 entitled "Organotin Oxide Hydroxide Patterning Compositions, Precursors, and Patterning", all of which are incorporated herein by reference. Other organometallic patterning compositions based on various metals are described in published U.S. Patent Application 2002 / 0076495 to Maloney et al., entitled "Method of Making Electronic Material," and U.S. Patent 9,372,402 B2 to Freedman et al., entitled "Molecular Organometallic Resists for EUV," both of which are incorporated herein by reference. Applicants have developed organotin patterning materials that have been developed to a very high degree, and some of these materials are exemplary compositions.

[0034] Monoalkyl tin alkoxides and monoalkyl tin amides have been formed with extremely low metal contamination in the parts-per-billion range. The tin composition can be selected to have high EUV absorption so that the composition can be used for EUV patterning in semiconductor manufacturing. In particular, it has been found that monoalkyl tin compositions can provide very effective EUV patterning resists that can be used to form very fine structures. It has been found that fractionation is effective for the purification of metal impurities of the compound. The treatment can also be used to separate monoalkyl tin compounds from polyalkyl tin contaminants. The purified composition can then be further diluted with semiconductor-grade solvents and optional other compositions to form the desired patterned product. Additionally or alternatively, improved filtering techniques can also provide low particulate contamination in radiation resist compositions. The purified radiation resist composition is suitable for patterning very small features with low patterned product failure rates and high yields.

[0035] For semiconductor processing and other microelectronic applications, metal contaminants may be harmful and may cause product failure and high processing loss rate due to the failure of components to meet specification requirements. For some metal contaminants, the threshold contamination level that may be harmful to semiconductor products may be very low. Therefore, there is a considerable motivation to significantly reduce metal contaminants. Patterning based on radiation has become a key process technology for forming shrinking component sizes, and the demand for this reduction has pushed radiation-based patterning to higher energy radiation ranges, such as extreme ultraviolet and electron beams. In order to utilize finer patterns that can be obtained using higher energy radiation, it has been found that radiation resists based on organic metals (particularly organic tin compounds) have high-level performance. For the treatment performed using organic tin compounds, in addition to managing the introduction and removal of tin, it is also desirable to avoid the introduction of contamination caused by other metals. Based on the treatment developed by the applicant, contaminated metals can be reduced to one billionth on a mass level.

[0036] It has been found that appropriate purification treatment can be used to effectively reduce non-tin metal contamination to very low levels, particularly for monoalkyl tin trialkoxides and monoalkyl tin triamines. Based on the experience of applying these compositions to radiation resist materials, it is also possible to expect to eliminate polyalkyl tin compounds, and the treatment for reducing metal contaminants can also effectively remove polyalkyl tin contaminants. Especially, monoalkyl tin trialkoxides and monoalkyl tin triamines can be purified by utilizing suitable distillation columns, and by suitably selecting fractionation in some embodiments. Processing the purified composition accordingly can keep the high purity of the composition. In addition, the purified composition can be filtered to remove particulate contaminants that may cause patterning defects. Improved filtration can use a continuous impeller pump to make photoresist circulate and recirculate through a semiconductor-grade filter to remove particulates. The particulate removal can be verified using in line light scattering measurements.

[0037] The use of organometallic tin composition as photoresist, especially for patterning based on extreme ultraviolet, is usually based on monoalkyl tin oxyhydroxy compound.The oxyhydroxy compound can be prepared in solution, or the oxyhydroxy compound can be prepared during the in-situ coating process involving RSnX3 compound (wherein R is alkyl, Sn-X is a hydrolyzable group) hydrolyzed in water and / or after the in-situ coating process.Monoalkyl tin triamine and monoalkyl tin trialkoxide are suitable precursor compounds for forming monoalkyl tin oxyhydroxy compounds, and monoalkyl tin triamine is a suitable precursor for forming monoalkyl tin trialkoxide.The current best practice using these resist compositions includes forming a coating of monoalkyl tin trialkoxide, and the in-situ hydrolysis of the trialkoxide is to form an oxyhydroxy composition with a volatile alcohol byproduct that is easily evaporated.The processing and composition described herein can be generally used for the aforementioned process and composition, and for other photoresist patterning processes and compositions based on monoalkyl tin outside the current best practice. Thus, monoalkyltin triamines can be useful intermediates in the preparation of organotin photoresists by their use in the synthesis of monoalkyltin trialkoxides or for deposition and in-situ processing to form monoalkyltinoxyhydroxy compositions. Improved purification techniques can be combined with improved synthesis techniques. Improved synthesis techniques and improved distillation methods are further described in co-pending U.S. patent application Ser. No. 15 / 950,292 (hereinafter referred to as the '292 application) to Edson et al., entitled "Monoalkyltin Compounds With Low Polyalkyl Contamination, Their Compositions and Methods," which is incorporated herein by reference.

[0038] The use of alkylmetal organometallic compounds in high performance radiation based patterning compositions is described, for example, in US Pat. No. 9,310,684 to Meyers et al., entitled "Organometallic Solution Based High Resolution Patterning Compositions," which is incorporated herein by reference. The refinement of these organometallic compositions for patterning is described in published U.S. patent application 2016 / 0116839A1, entitled “Organometallic Solution Based High Resolution Patterning Compositions and Corresponding Methods,” by Meyers et al., and published U.S. patent application 2017 / 0102612A1, entitled “Organotin Oxide Hydroxide Patterning Compositions, Precursors, and Patterning,” by Meyers et al. (hereinafter referred to as the '612 application), both of which are incorporated herein by reference.

[0039] The alkyltin precursor composition includes a group that can be hydrolyzed with water or other suitable reagents under suitable conditions to form an alkyltinoxyhydroxy patterning composition, which group can be represented by the formula RSnO (1.5-(X / 2)) (OH) X Represents, wherein 0<X≤3. The hydrolysis condensation reaction that can convert the composition having hydrolyzable Sn-X groups is shown in the following reaction:

[0040] RSnX3+3H2O→RSn(OH)3+3HX,

[0041] RSn(OH)3→RSnO (1.5-(x / 2)) OH x +(x / 2)H2O.

[0042] If the hydrolysis product HX is sufficiently volatile, the hydrolysis can be performed in situ using water vapor during the substrate coating process, but the hydrolysis reaction can also be performed in solution to form the alkyltinoxyhydroxy composition. These processing options are further described in the '612 application.

[0043] The monoalkyltin triamine composition can generally be represented by the formula RSn(NR')3, wherein R and R' independently have an alkyl or cycloalkyl group of 1-31 carbon atoms, and one or more carbon atoms are optionally substituted with one or more heteroatom functional groups, such as groups containing O, N, Si, Ge, Sn, Te and / or halogen atoms, or alkyl or cycloalkyl groups further functionalized with phenyl or cyano groups. In some embodiments, R' may contain ≤10 carbon atoms and may be, for example, methyl, ethyl, propyl, isopropyl, butyl, tert-butyl, isobutyl or tert-amyl. The R group may be a straight chain, a branched chain (i.e., a secondary or tertiary carbon atom bonded to the metal), or a cyclic hydrocarbon group. Each R group independently and generally has 1-31 carbon atoms, wherein the group having a secondary bonded carbon atom has 3-31 carbon atoms, and the group having a tertiary bonded carbon atom has 4-31 carbon atoms. In particular, branched alkyl ligands may be suitably used in certain patterning compositions, wherein the compound in the patterning composition may be composed of R 1 R 2 R 3 CSn(NR′)3 represents, where R 1 and R 2 are independently an alkyl group having 1 to 10 carbon atoms, R 3 is hydrogen or an alkyl group having 1 to 10 carbon atoms. As described below, this representation of the alkyl ligand R can be similarly applied to other commonly used R 1 R 2 R 3 CSn(X)3, wherein X corresponds to a trialkoxy or triamine moiety. In some embodiments, R 1 and R 2 can form a cycloalkyl moiety, and R 3 It can also be combined with other groups in the cyclic part. Suitable branched alkyl ligands can be, for example, isopropyl (R 1 and R 2 is methyl, and R 3 is hydrogen), tert-butyl (R 1 , R 2 and R 3 is methyl), tert-amyl (R 1 and R 2 is methyl, and R 3 -CH2CH3), sec-butyl (R 1 is methyl, R 2 is -CH2CH3, and R 3 is hydrogen), neopentyl (R 1 and R 2 is hydrogen, and R 3For example, cyclohexyl, cyclopentyl, cyclobutyl, and cyclopropyl. Examples of suitable cyclic groups include, for example, 1-adamantyl (-C(CH2)3(CH)3(CH2)3, or tricyclo (3.3.1.13,7) decane with tertiary carbon bonded to the metal) and 2-adamantyl (-CH(CH)2(CH2)4(CH)2(CH2), or tricyclo (3.3.1.13,7) decane with secondary carbon bonded to the metal). In other embodiments, the hydrocarbon group may include an aryl or alkenyl group (e.g., benzyl or allyl), or an alkynyl group. In other embodiments, the hydrocarbon ligand R may include any group consisting only of C and H and containing 1-31 carbon atoms. In summary, some examples of suitable alkyl groups bonded to tin include, for example, straight or branched chain alkyl groups (isopropyl (CH3) 2CH-), tert-butyl (CH3) 3C-), methyl (CH3-), n-butyl (CH3CH2CH2CH2-)), cycloalkyl groups (cyclopropyl, cyclobutyl, cyclopentyl), olefins (alkenyl, aryl, allyl), or alkynyl, or combinations thereof. In further embodiments, suitable R groups may include hydrocarbon groups substituted with heteroatom functional groups, including cyano, thiol, silyl, ether, ketone, ester, or halide groups, or combinations thereof.

[0044] The alkyltin trialkoxide composition can be composed of the formula RSn(OR 0 )3. Alkyl tin trialkoxides can be synthesized from alkyl tin triamines, but other synthetic routes can also be used, such as those described in the '292 application, in which the synthesis of monoalkyl tin trialkoxides is achieved via alkyl triamidotin compositions. Alkyl triamidotin compositions can be represented by the formula RSn(NR"COR"')3. The R group (R) in the formula of alkyl tin trialkoxides and alkyl triamidotin compositions is 0 , R", R"') can be the same R groups as outlined above for the alkyltintriamine compositions, and the corresponding discussion of these R groups above is fully incorporated into this paragraph as if replicated. Monoalkyltriamidotin compositions are not further described here. For the alkoxy ligand -OR 0 , R 0 The groups may independently be hydrocarbon groups having 1 to 10 carbon atoms, such as methyl, ethyl, and the like.

[0045] Consistent with common terminology in the art, "alkyltin" compounds refer to a wide range of organic ligands with C-Sn bonds, where the ligands are not necessarily directed to aliphatic alkane-based moieties in which the C-H bonds are replaced by C-Sn bonds. Therefore, in a sense, alkyltins can be considered to be "organotin" moieties using C-Sn bonds. Similarly, monoalkyltin moieties refer to compounds with a single C-Sn bond. The above discussion focuses on some details of monoalkyltin triamines (organotin triamines) and monoalkyltin trialkoxides (organotin trialkoxides) compounds, which have been found to be very effective precursors for forming radiation patternable coatings, including a more general discussion of other hydrolyzable ligands can be found in the context of the following coating process, and the teachings of this article are more generally applicable to a wider range of tin compounds with hydrolyzable ligands.

[0046] The polyalkyltin impurity composition may affect the condensation of the coated resist material and contribute to the outgassing of the radiation resist during the photolithographic process, which increases the possibility of tin contamination of the equipment used for film deposition and patterning. Based on these considerations, it is highly desirable to reduce or eliminate the dialkyl or other polyalkyl components of the resist composition. Monoalkyltin trialkoxide compositions can be desirable components in the precursor patterning composition solution because the monoalkyltin trialkoxide compositions are suitable for in situ hydrolysis and condensation to form monoalkyltin oxyhydroxy compositions with alcohol byproducts, wherein the alcohol byproducts are generally volatilized and removed in correspondence with the in situ hydrolysis.

[0047] By using the appropriate method described in the '292 application, monoalkyltintriamine compositions with relatively low polyalkyl contaminants can be directly synthesized. In addition, it has been found that the fractionation process can effectively remove monoalkyltintriamines and non-tin metal contaminants and polyalkyltin contaminants for monoalkyltintrialkoxides. The realization of very low polyalkyl contamination levels is described in detail in the published U.S. patent application 2020 / 0241413 (hereinafter referred to as the '413 application) by Clark et al., entitled "Monoalkyl Tin Trialkoxides and / or Monoalkyl Tin Triamides With Low Metal Contamination and / or Particulate Contamination, and Corresponding Methods", which is incorporated herein by reference.

[0048] The resist precursor composition can be conveniently specified based on the molar concentration of tin ions. The resist precursor composition can have a low non-tin metal contamination value as specified in the previous paragraph. Typically, the resist precursor solution typically comprises a tin cation of about 0.0025M to about 1.4M, a tin cation of about 0.004M to about 1M in some embodiments, a tin cation of about 0.005M to about 0.75M in a further embodiment, a tin cation of about 0.01M to about 1M in some embodiments, and a tin cation of about 0.01M to about 0.5M in another embodiment. Those of ordinary skill in the art will recognize that other concentration ranges and values ​​within the above-mentioned clear and explicit ranges are contemplated and within the scope of the present disclosure.

[0049] Suitable solvents for forming the resist precursor coating solution are described below, and in an example, 4-methyl-2-pentanol is used as the solvent. Semiconductor-grade solvents with metal contamination levels of 1 part per billion are commercially available from Alfa Aesar, Fuji Film, KMG Chemical (TX, USA), TOK USA, Honeywell Electronic Materials, Taiwan Refine, and other suppliers. Proper handling of solutions and storage containers and dilution of the monoalkyl tin composition with a suitable semiconductor-grade solvent can limit any introduction of undesirable contaminants during further processing.

[0050] Ultrapure solvents are typically stored and shipped in plastic containers made of high-density polyethylene (HDPE), polytetrafluoroethylene (PTFE), or polypropylene (PP). CLEANRARRIR from Aicelol Corporation TM (CB) bottles are made of HDPE and are designed to store and transport pure semiconductor grade chemicals with low particulate counts and low trace metal concentrations. Photoresists can also be stored in dealkalized glass bottles. Commercial containers are typically made of soda-lime glass. This glass contains a high concentration of sodium, and solvents and liquids can leach from the glass. The dealkalization process consumes sodium from the surface of the glass container to reduce sodium leaching.

[0051] In order to realize the low defect patternable coating of organometallic resist, monoalkyl tin composition can be filtered to remove particulate contaminants. The improved process for performing filtration is described in detail below. Filtration and the evaluation of the filtered composition are performed using the organometallic resist precursor dissolved in the solvent. Since it is desired to filter the resist composition directly and then load it into the container for storage and transportation, the concentration of the resist composition is usually diluted. The tin concentration in the resist precursor composition is as described above.

[0052] Particle measurement equipment can be used to measure particle contamination. For example, for photoresists, Rion Corporation (Japan) sells a particle counter based on light scattering, and this particle counter is used in the examples below. A properly selected particle counter can perform on-line particle measurement by sampling a solution from a filtered flow system. The results of the particle measurement are expressed in terms of the number of particles per milliliter (mL) of fluid. A specific particle counter will have a selected particle size measurement range, and the results in the examples below provide particle counts under a specific size range.

[0053] Removal of particles from organometallic photoresists is described in published PCT application WO 2017 / 163922 (hereinafter referred to as the Tsubaki application), entitled "Active Ray-Sensitive or Radiation-Sensitive Composition, Method for Purifying Active Ray-Sensitive or Radiation-Sensitive Composition, Pattern-Forming Method, and Method for Producing Electronic Device" by Tsubaki et al., which is incorporated herein by reference. The filtering method in the Tsubaki application is for various metal compounds with selected ligands, and butyltin oxide hydroxide (C4H9-SnOOH) is exemplified in Example 9. Tsubaki did not discuss filtering alkyl metal alkoxides. Improvements in filtering organometallic resists (particularly alkyl metal alkoxides) are described in the '413 application. The filtering process described herein provides further improvements toward the goal of further reducing the unpatterned defect values ​​of wafer resist coatings.

[0054] Resist compositions comprising monoalkyl metal trialkoxides and / or monoalkyl tin triamines at a concentration of about 0.0025 M to about 1.4 M (and in some embodiments, about 0.01 M to about 0.5 M) (based on moles of tin) in an organic solvent can be purified to remove particles so that the solution does not exceed about 0.5 particles / mL (average size of particles greater than 150 nm), in further embodiments does not exceed about 0.25 particles / mL, and in yet other embodiments does not exceed about 0.2 particles / mL (average size of particles greater than 150 nm) as determined by light scattering. Using a commercially available particle counter, such as the Rison KS-41B Liquid-borne Particle Sensor with optional functionality, particles as small as 70 nm can be counted using light scattering. Using the filtration techniques herein, alkyl metal alkoxides in organic solvents at concentrations of 0.025 M to 1.4 M (and in some embodiments, concentrations of about 0.05 M to about 0.5 M) (based on moles of tin) can be purified to have a particle contamination of particles between 70 nm and 150 nm in size of no more than 8.0 particles / mL, in further embodiments no more than 5.0 particles / mL, and in yet other embodiments no more than 4.0 particles / mL. One of ordinary skill in the art will recognize that other ranges of particle contamination within the explicit ranges above are contemplated and within the scope of the present disclosure.

[0055] As mentioned above, monoalkyltin triamines also can be used for synthesizing corresponding monoalkyltin trialkoxides, but can also use other methods to synthesize monoalkyltin trialkoxides.Especially, monoalkyltin trialkoxides can be prepared by making corresponding monoalkyltin triamines react with alcohol.Low polyalkyltin pollutants in the monoalkyltin triamines may be brought into the product monoalkyltin trialkoxides, so that the product monoalkyltin trialkoxides have the low dialkyltin pollutants that are basically in the above molar percentage described for the monoalkyltriamines.Alcohol is selected to provide the alkoxy group of expectation, so that alcohol ROH introduces-OR base as the ligand that is connected with tin.Suitable R base list is provided above, and alcohol is related accordingly.The example of tertiary amyl alcohol is provided hereinafter, but other alcohols also can be used to provide the-OR alkoxy ligand of expectation similarly.

[0056] Further processing of the purified monoalkyltin composition typically involves diluting the composition with an organic solvent. The diluted composition can be filtered to remove particulates. Filtration can be performed at one or more suitable process points, such as before use in further reactions, before placing the resist composition into a container for storage and / or transportation, and / or in a process line via transport on a commercial wafer track. Improved processing is described herein that is particularly useful for filtering monoalkyltin trialkoxides.

[0057] In some embodiments, the filtration apparatus can be configured to perform repeated filtration of the organometallic composition, such as by configuring a recirculation system and / or implementing a continuous filtration system. The container can be equipped with a drain port and a backfill port for recirculation of the filtered composition. One or more pumps can be used to drive the fluid through the filtration system, and suitable filters can be used in the pipeline to remove small particles from the fluid. Clean pipes can be used to connect the system to the flow between the various components.

[0058] Figure 1 A schematic diagram of a filtration system 140 from the '498 application is shown. A composition to be filtered may be located in a container 142 having an outlet 144, an inlet 146, and (one or more) ports 148. Flow from the outlet may be controlled using one or more pumps 150. The flow path then passes through a first filter 152, and optionally through additional (one or more) filters 154. A flow meter 156 may be used to monitor the flow rate through the system. A particle analyzer 158 may be configured to measure particles within the filtered stream. Although Figure 1 A particle analyzer 158 is shown in-line with the flow, but other suitable configurations, such as a sampling configuration, may be used. The filtered flow may be directed to be recirculated through a recirculation line 160 connected to an inlet 146 of the container 142, or collected through a collection line 162 directed to a collection container 164. A valve 165 may be used to selectively direct the flow to the recirculation line 160 or the collection line 162. In some embodiments, a valve 166 may be used to divert the filtered flow to a collection container 168, such as in a recirculation configuration, when the particle count drops below a selected value. The flow may be directed through a suitable conduit, such as a polymer conduit.

[0059] If desired, the fluid in the collection container 164 can be further filtered in a recirculation configuration or another in-line filtration configuration. The recirculation configuration of the collection container 164 can be conceived by conceptually reproducing a circulating flow loop connected to the container 142, including (one or more) pumps, (one or more) filters, a particle analyzer, and other required components, and connecting these components specifically to the collection container 164. Figure 1As shown, a second series filtration configuration is shown. One or more pumps 172 can be used to control the flow from the outlet 170 of the collection container 164, and the pump 172 guides the flow to one or more filters 174. The flow from (one or more) filters 174 can be guided through a particle analyzer 176 and a flow meter 178 (located at a convenient position along the flow path) that can be located in a pipeline or in a sampling configuration. The filtered flow can be collected in a bottle 180. Similarly, suitable polymer pipes or other suitable flow conduits can be used to guide the flow through the filtration system. If necessary, further continuous filtration and / or a combination of recirculation and continuous filtration can be performed by repeating the filtration system. In a filtration system with two or more stages, the filter for post-stage filtration can be selected to have the ability to remove finer particles. For example, the first stage filtration can be performed using a filter with a rated particle size cutoff of 5nm to 15nm, and the second stage filtration can be performed using a filter with a rated particle size cutoff of 1nm to 3nm. In some embodiments, the first stage filtration can involve recirculation, and the second stage is a series configuration.

[0060] The schematic layout of the dual track resist purification system 250 is shown in Figure 2 284. The composition to be filtered can be introduced into the container 252 through the inlet 284. The container 252 has inlets 258 and 284, an outlet 256 and (one or more) inlet and outlet 262. In some embodiments, (one or more) inlet and outlet 262 are used to introduce an inert gas (such as argon or nitrogen) into the container 252, or release gas from the container 252. The pressure gauge 264 can be used to monitor the pressure in the container 252. In some embodiments, the container 252 can have a capacity of about 55 gallons, but other sizes can be used as needed. In some embodiments, the container 252 is a mixing tank including a stirring element, and can be used to initially mix the precursor composition and the solvent, and / or incorporate the stream from the inlet 284. In some embodiments, the precursor composition is a tin-based precursor composition. The stream from the outlet 256 can be controlled using one or more pumps 266. In some embodiments, the pump 266 is an impeller pump. The stream passes through the first filter 268 and other optional (one or more) filters. In some embodiments, the suitable filter for the first filter 268 is described below. Temperature unit 270 can be used to monitor and / or control the temperature of the stream. In some embodiments, the temperature of the tank is maintained at a constant temperature, typically between about 18°C ​​and 35°C. Pressure gauges 272 and 274 can be used to monitor the pressure of the stream before and after the first filter 268. Particle analyzer 276 can be configured to measure the liquid particle count within the filtered stream. Although Figure 2A particle analyzer 276 is shown in line with the flow, but other suitable configurations, such as sampling configurations, may be used. A flow meter 278 may be used to monitor the flow rate through the first flow loop. The user may select one or more parameters for directing the filtered flow at valve 261 (typically a three-way valve) to be recirculated via inlet 284 or further filtered in a second flow loop via transfer line 260 through appropriate control of valve 261. The parameters may include a volume turnover number calculated as the total volume of the flow that has passed through the selected filter (such as first filter 268) divided by the total volume of flow in the system. In some embodiments, the flow is directed to the second flow loop when the particle count drops below a selected value and / or the volume turnover parameter is above certain thresholds. The volume conversion number may be at least 5 turnovers; at least about 10 turnovers in further embodiments; at least 15 turnovers in some embodiments; at least 30 volume turnovers in further embodiments; and at least 45 volume turnovers in further embodiments. Turnover means that the flow through the filter loop corresponds to the total volume of the resist being processed. Those of ordinary skill in the art will recognize that other turnover ranges within the above-mentioned clear ranges are expected and within the scope of the present disclosure. Increasing the volume turnover number will generally result in a reduction in particles, but with additional turnovers, the progressive improvement effect will generally decrease. Inlet 258 is shown as having a spray ball 286. In some embodiments, inlet 258 and spray ball 286 are used to introduce a clean stream into container 252 for use between processing batches. Optionally, inlet 258 can deliver the filtered stream to container 242. Container 252, outlet 256, pump 266, first filter 268, particle analyzer 276, flow meter 278 and inlet 284 are elements of the first filter or flow loop.

[0061] The filtered stream directed to the second flow loop for further filtration via valve 261 flows along transfer line 260 through valve 323 (typically a three-way valve) and enters container 292 through inlet 296. One or more pumps 266 may be used to control the flow. In some embodiments, pump 266 is an impeller pump, such as the pump described further below. Although other configurations may be suitable, in an exemplary embodiment, the first flow loop has one larger capacity impeller pump and the second flow loop has two impeller pumps in series.

[0062] The container 292 is shown as having inlets 296 and 300, an outlet 298, and (one or more) inlets and outlets 302. In some embodiments, (one or more) inlets and outlets 302 are used to introduce argon into the container 292 or release gas from the container 292. A pressure gauge 294 can be used to monitor the pressure in the container 292. In some embodiments, the container 292 can have a capacity of about 55 gallons. In some embodiments, the container 292 is a mixing tank and can be used to incorporate a flow from the inlet 296. The flow from the outlet 298 can be controlled using one or more pumps 304. In some embodiments, the pump 304 is an impeller pump. The flow passes through the second filter 308 and optional other (one or more) filters. In some embodiments, suitable filters for the second filter 308 are described below. The first flow loop and the second flow loop can have the same or different filter types. For example, relative to the filter (such as a 1nm filter) for the second flow loop, the first flow loop can have a slightly larger filter size cutoff value (such as 3nm). The temperature unit 310 can be used to monitor and / or control the temperature of the flow. Pressure gauges 312 and 314 may be used to monitor the pressure of the flow before and after the second filter 308. A particle analyzer 316 may be configured to measure particles within the filtered flow. Figure 2 A particle analyzer 316 is shown on the pipeline of the flow, but other suitable configurations, such as sampling configurations, can be used. The flow is further directed through a clean room and enters a bottling room 318, which can be a clean room. The filtered flow can be partially or completely diverted to be collected via a bottling unit 320 or passed through a bottling unit 320 for further filtering. A flow meter 322 can be used to monitor the flow rate through the system. The filtered flow that is recycled flows through a valve 323 to the inlet 296 of the container 292. The inlet 300 is shown as having a spray ball 326. In some embodiments, the inlet 300 and the spray ball 326 are used to introduce a cleaning fluid into the container 292 between processing batches. Alternatively, the inlet 300 can deliver the filtered flow to the container 292. The container 292, the outlet 298, (one or more) pumps 304, the second filter 308, the particle analyzer 316, the bottling unit 320, the flow meter 322 and the inlet 296 are elements of the second filtering or flow loop. The bottling unit 320 may be a higher grade, cleaner environment than the bottling room 318. In the exemplary embodiment described in the following example of a dual loop filtration system, the bottling room 318 is a FS209E grade 1000 (ISO 6) clean room and the bottling unit 320 is a FS209E grade 100 (ISO 5) clean room.

[0063] Typically, the pipes used to connect the components can be polymer pipes with very high chemical inertness, such as polytetrafluoroethylene pipes. At reasonable pipe thickness, the pipes may suffer from some water migration. Although water migration may cause some particle formation, this may not be a significant problem due to particle filtration. In some embodiments, the pipes can be replaced with non-permeable materials (such as metals), but these materials may be more likely to provide contaminants. Optionally, the polymer pipes can be wrapped with air jackets or metal foils or coatings to mitigate any water migration risks.

[0064] The filtered flow can be diverted from the second filter circuit via the branch valve 334 to be collected in the bottle 330. The user can select one or more parameters for diverting the filtered flow from the second filter circuit for collection. The parameters can include a volume turnover number, which is calculated as the total volume of the flow that has passed through the selected filter (such as the second filter 308) divided by the total volume of the flow in the system. In some embodiments, the flow is diverted for collection when the particle count drops below a selected value and / or the volume turnover parameter is above a certain threshold. In some embodiments, the volume turnover number can be at least 5 turnovers; in some embodiments, at least 15 turnovers, in other embodiments, at least 30 volume turnovers; and in other embodiments, at least 45 volume turnovers. Increasing the volume turnover number generally results in a reduction in particles, but the incremental improvement effect generally decreases with additional turnovers. Alternatively or additionally, the measured particle count can be used to determine the suitability for bottling. In some embodiments, bottling is performed after no more than about 10 particles / mL (particle size 70nm or larger) are measured; in other embodiments no more than about 5 particles / mL; in some embodiments no more than about 4 particles / mL; and in other embodiments no more than 1 particle / mL (particle size 70nm or larger) and no particles 150nm or larger in size are measured (<0.05 particles / mL). The bottling tool can be connected to the bottling unit 320 using suitable polymer tubing or other suitable flow conduits and used to sequentially fill bottles 330 within the clean room.

[0065] For wherein container is configured to closed loop configuration to provide the embodiment of recirculation, the lid of the container of composition to be filtered is provided and can be configured to have a plurality of ports.A port can be used for the fluid removal to be pumped to the filter, and another port can be used for the filtered fluid transport back in the container, and other ports can be used for various other functions.For example, another port of the container lid can be used for the filtered fluid transport to the packaging container.The specific embodiment of filtering equipment is described in more detail in the following examples.

[0066] While any of a variety of pumps may be used to drive the filter flow, it has been found that an impeller pump provides surprisingly improved filtration performance. While not wishing to be bound by theory, the more uniform pressure delivered by the impeller pump is believed to improve the performance of the filter in removing particulates by reducing pressure fluctuations. This improved filtration was demonstrated in an example where filtration using an impeller pump was compared to a diaphragm pump using the same filter. Suitable impeller pumps include, in particular, the 1000-1000 diaphragm pump from Levitra AG. (Switzerland) magnetically suspended impeller pump. Due to the high viscosity of monoalkyltin trialkoxide, two or more can be placed in series. Pump to obtain the desired flow rate. Magnetic levitation pumps provide low shear forces on the liquid during pumping and stable pressure. The flow rate through the system is generally dependent on filter selection, pump selection, pipe size, temperature and pressure, and is affected by fluid viscosity.

[0067] Filters suitable for in-line filtration of resist compositions are commercially available. For example, photoresist filters are available from Entegris (e.g., and Microgard TM UC / UCP series filters) and Nippon Pall Co. Ltd (Japan, such as PE-Kleen filters and PhotoKlean TM DDF P-Nylon). The particle filtration rating of the filter can be specified as low as <5nm, >3nm or >1nm, but smaller pore sizes may reduce flow rate. As described in the examples, filters with a rated pore size of >1nm can achieve the desired performance. Typically, the particle filtration rating can be 50nm (i.e., removing particles larger than 50nm in size), 25nm, 10nm, 5nm, 3nm, 2nm or 1nm. Those of ordinary skill in the art will recognize that other ranges of particle filtration ratings within the above explicit ranges are contemplated and within the scope of the present disclosure.

[0068] To remove particulates, the purified monoalkyltin composition can be placed in a clean container that is equipped to pump out the composition for filtration. Suitable filtration systems are outlined above. As described above, various configurations can be used. For recycling, the composition can be typically recycled (in terms of volume turnover) 1 to 100 times; 2 to 80 times in some embodiments; and 5 to 65 times in other embodiments. One of ordinary skill in the art will recognize that other turnover ranges within the above-defined ranges are expected and within the scope of the present disclosure. Although suitable performance can generally be achieved within a specific range, more recycling can be performed. For continuous filtration, the composition can be filtered continuously 1 to 10 times. One of ordinary skill in the art will recognize that other ranges of the number of filtration steps within the above-defined ranges are expected and within the scope of the present disclosure. Filtration can be performed immediately before the radiation-sensitive resist composition is placed in a container for transport and / or before the composition is used for patterning purposes in a production line. In any case, the filtration system can be configured to avoid contamination of the radiation resist composition by metal contaminants and / or particulate contaminants. If the filtered composition is placed in a container for transport, the container can be sealed and appropriately transported to the end-use facility where appropriate cleaning treatment can be performed to deliver the composition to the process equipment. As mentioned above, a portion of the treatment in the coating and treatment line is also important for reducing defects. This treatment is discussed below.

[0069] Tubing preparation and bottle installation

[0070] During high volume manufacturing, photoresist and other chemicals are typically installed (plumbed) onto wafer processing tracks to enable the use of the chemicals as needed and / or during programmed track recipes. When it is desired to use a new material on the same line, it is typically desired to purge the line of previous material by flowing a sufficient amount of solvent through the line and / or by flowing a sufficient amount of new material through the line to ensure that the material delivered on the wafer is substantially the desired material.

[0071] Usually can be by before utilizing the expected material to fill the pipeline, utilize appropriate solvent flushing pipeline to carry out pipeline preparation.Solvent selection is not particularly limited, but suitable solvent is generally the solvent that can dissolve with the residual material in pipeline.Suitable solvent can comprise almost any organic solvent, aqueous acid and aqueous alkali and its combination.Especially, suitable solvent comprises for example aromatic compound (for example, dimethylbenzene, toluene), ether (anisole, tetrahydrofuran), ester (propylene glycol monomethyl ether acetate, ethyl acetate, ethyl lactate), alcohol (for example, 4-methyl-2-pentanol, 1-butanol, methanol, isopropanol, 1-propanol), ketone (for example, methyl ethyl ketone), lactam and lactone (for example, N-methyl-2-pyrrolidone, butyrolactone), carboxylic acid (for example, formic acid, acetic acid, oxalic acid, lactic acid), aqueous acid (HCl, H2SO4, HNO3), aqueous alkali (tetramethylammonium hydroxide, tetrabutylammonium hydroxide), water, its mixture etc. Typically, solvent selection may be influenced by solubility parameters, volatility, flammability, toxicity, viscosity, and potential chemical interactions with other process materials or materials of construction. Typically, an appropriate solvent may be flowed through a line until a desired metric (e.g., liquid particle count or on-wafer defect count) is passed.

[0072] After preparing the pipeline for installing the new material, a new bottle can be installed on the track. In one example of bottle installation, a bottle containing a photoresist solution can be placed in a chemical box and then a piercer (i.e., a needle or line source) is immersed in the bottle. The piercer is attached to a line or pipe that allows the resist solution to be delivered to the desired module within the track, such as a spin coater module.

[0073] When photoresist is installed on track, it is usually also expected to keep material flowing through pipeline during the service life of bottle.For the time when resist is not deposited on wafer, flow is usually realized by using virtual distribution process, wherein material is periodically distributed to coating chamber and / or distributed in discharge line from installed bottle, so as to ensure that material in pipeline will not stagnate for a long time, because stagnation may be associated with defect formation, which may be caused by microparticle formation caused by water migration in pipeline.Usually, pipelines and pipelines in wafer track are made of fluorocarbon polymers (such as PTFE, PFA etc.).Although do not want to be limited to theory, it is known that many fluorocarbon polymers show certain permeability to water vapor, for example, which may react with organometallic, inorganic and metal oxide photoresists subsequently, thus causing the formation of microparticles.Other nucleation processes that may cause microparticle generation may be produced by other mechanisms.

[0074] However, it is generally desirable to limit the residence time of the material in the pipeline. In some embodiments, the virtual distribution can distribute at least about 0.1 mL of material; in other embodiments, at least about 0.25 mL of material; in other embodiments, at least about 0.5 mL of material; and in other embodiments, at least about 1 mL of material. It is convenient to perform virtual distribution of the resist in a pulsed manner during the selected time period when no active coating is performed. The frequency of virtual distribution can occur at least once every 2 hours; in other embodiments, at least once every 60 minutes; in some embodiments, at least once every 45 minutes; in other embodiments, at least once every 30 minutes. In an exemplary embodiment, 3 ml is pulsed every 20 minutes. Although pulsed virtual distribution is convenient for incorporation into a wafer coating track, the distribution flow rate of the pulsed flow can be adjusted to a continuous flow of a continuous flow rate to achieve an overall equivalent flow over a long period of time. Those of ordinary skill in the art will recognize that other ranges of volume and frequency are expected and within the scope of the present invention. Those of ordinary skill in the art can usually find suitable volumes and distribution frequencies by finding respective appropriate values ​​that achieve an acceptable balance of defect rate results and material consumption through routine experiments.

[0075] The schematic layout of the wafer rail system 340 is shown in Figure 3 354 has a cap 355 and contains filtered photoresist solution 352. In some embodiments, the filtered photoresist solution 352 in bottle 354 can be removed by Figure 2 The dual-track photoresist purification system 250 is shown. Figure 3In the system of FIG. 340 , an inert gas 350 is delivered to a bottle 354 through a flow line 351 or other suitable stopcock inserted into a cap 355 or replacing the cap. In an embodiment, the inert gas 350 is nitrogen. The filtered photoresist solution 352 is removed from the bottle 354 by a piercer 357, wherein the piercer 357 is attached to a photoresist delivery line 356. The wafer track system 340 may include (one or more) retention tanks 358 and (one or more) pumps 360, and the filtered photoresist solution 352 is delivered to a coating module 362 by (one or more) pumps 360. A control valve 361 may be used to adjust the flow rate of the photoresist solution to the coating module 362. The coating module 362 is shown to have a delivery nozzle 364, a discharge portion 368 and a wafer 366. The photoresist solution 352 is delivered to the wafer 366 by the delivery nozzle 364. In some embodiments, the photoresist solution 253 passes through a filter 263 before being delivered to the wafer 366 through a delivery nozzle 364. A drain 368 is provided to remove excess material, such as the photoresist solution 352. In some desirable embodiments, the pump(s) 360 include one or more impeller pumps as described above to provide more uniform pressure and reduce particle formation. In some embodiments, a container 369 is provided to collect the initial flow and / or the virtual dispense flow of the photoresist solution 352. The container 369 has a drain line 370 connected to the drain 368. In some embodiments, the container 369 is provided as a Figure 3 366 is positioned as shown in the figure, and the wafer 366 is not shown. In other embodiments, the wafer 366 is not shown, and the delivery nozzle 364 and the container 369 can be conveniently positioned laterally, such as positioned above the discharge portion 368. In other embodiments, the wafer 366 is not shown, and the delivery nozzle 364 can be conveniently positioned laterally or extended, such as positioned above the discharge portion 368 and extending toward the discharge portion 368. In such an embodiment, the container 369 may not exist, or may be positioned above the discharge portion 368. The wafer track system 340 is typically located in a manufacturing facility with a controlled environment in which the temperature and relative humidity are maintained close to selected values ​​to provide consistency in processing. Therefore, an environment is maintained around the wafer processing. For example, the relative humidity can be controlled to be about 45%.

[0076] In some embodiments, in order to ensure that the liquid material deposited on the substrate contains sufficiently few particles and / or defects as desired, it is useful to flow the material through a filter before dispensing the material onto the wafer by using a point-of-use (POU) filter. The POU filter can be placed at or near the spin coater dispenser nozzle (such as within 1 meter), but the filter can be placed at a desired position along the delivery line to the spin coater. The characteristics of the POU filter are not particularly limited, as long as the construction material of the filter does not interact or react adversely with the material flowing through the filter, and examples of suitable POU filter types are the same as the filter types used to filter the prepared resist liquid described above. Other suitable filter types can be found by ordinary technicians in this field through routine experiments, and other suitable filter types can be obtained from well-known suppliers (such as Entegris, Pall, etc.). In some of the following examples, the POU filter is not used to analyze unpatterned wafer defects in order to provide information about whether the number of defects on the wafer is inherent to the material in the bottle. In other embodiments below, the POU filter is used to prove a coating with very low defects.

[0077] Deposition of coating

[0078] By depositing the precursor solution on the selected substrate and then processing the precursor solution, a coating material can be formed. Using the precursor solution described herein, some hydrolysis and condensation are usually carried out during coating, and can be completed or promoted via subsequent processing steps (such as, heating in air). The substrate usually has a surface on which the coating material can be deposited, and the substrate may include multiple layers, wherein the surface is related to the uppermost layer. In certain embodiments, the substrate surface can be processed to prepare a surface for adhering the coating material. In addition, the surface can be properly cleaned and / or the surface can be smoothed. Suitable substrate surfaces can include any reasonable material. For example, some particularly interesting substrates include silicon wafers, silicon dioxide substrates, other inorganic materials (such as ceramic materials), polymer substrates (such as organic polymers, composite materials of organic polymers) and combinations thereof across the substrate surface and / or in the layer of the substrate. Wafers (such as relatively thin cylindrical structures) may be convenient, but structures of any reasonable shape can be used. The substrate with polymer layer on polymer substrate or non-polymer structure can be expected to be used for specific application based on their low cost and flexibility, and suitable polymer can be selected based on the relatively low processing temperature that can be used to process patternable material described herein.For example, suitable polymer can include polycarbonate, polyimide, polyester, polyolefin, its copolymer and its mixture.Usually, it is desired that substrate has flat surface, especially for high resolution application.However, in specific embodiment, substrate can have a large amount of morphology, wherein resist coating is intended to fill or planarize the feature for specific patterning application.

[0079] In general, any suitable solution coating process can be used to deliver the precursor solution to the substrate. For example, suitable coating methods can include spin coating, spray coating, dip coating, knife edge coating, printing methods (such as inkjet printing and screen printing), etc. Some of these coating methods form a pattern of the coating material during the coating process, although the resolution level currently available from printing and the like is significantly lower than the resolution level available from the radiation-based patterning described herein.

[0080] In some embodiments, although there may be edge effects, spin coating can be a desired method for relatively uniformly covering the substrate. In some embodiments, the wafer can be rotated at a rate of about 500rpm to about 10,000rpm; about 1000rpm to about 7500rpm in other embodiments, and about 2000rpm to about 6000rpm in other embodiments. The rotation speed can be adjusted to obtain a desired coating thickness. Spin coating can be performed for a time of about 5 seconds to about 5 minutes, and about 15 seconds to about 2 minutes in further embodiments. Initial low-speed rotation (e.g., at 50rpm to 250rpm) can be used to perform the initial overall spreading of the composition on the substrate. Backside rinsing, edge bead removal steps, etc. can be performed using water or other suitable solvents to remove any edge beads. Those of ordinary skill in the art will recognize that other ranges of spin coating parameters within the above-mentioned clear range are expected and within the scope of the present disclosure.

[0081] The thickness of the coating can generally be a function of the concentration of the precursor solution, the viscosity, and the rotation speed of the spin coating. For other coating processes, the thickness can also be generally adjusted by selecting the coating parameters. In some embodiments, it may be desirable to use a thin coating to facilitate the formation of small and high-resolution features in a subsequent patterning process. For example, the dried coating material can have an average thickness of no more than about 1 micron; no more than about 250 nanometers (nm) in other embodiments; about 1 nanometer (nm) to about 50nm in other embodiments; about 2nm to about 40nm in other embodiments; and about 3nm to about 25nm in some embodiments. A person of ordinary skill in the art will recognize that other ranges of thickness within the above-defined ranges are expected and within the scope of the present disclosure. The thickness can be estimated based on the optical properties of the film by using non-contact methods such as X-ray reflectivity and / or ellipsometry. Typically, the coating is relatively uniform for ease of handling. In some embodiments, the thickness variation of the coating does not vary by more than ±50% relative to the average coating thickness; and in further embodiments does not vary by more than ±40% relative to the average coating thickness; and in further embodiments does not vary by more than about ±25% relative to the average coating thickness. In some embodiments, such as high uniformity coatings on larger substrates, the coating uniformity can be evaluated by excluding about 3 mm edge, i.e., the coating uniformity is not evaluated for the portion within the 3 mm edge of the coating, but excluding 1 cm can also be used to achieve similar results. One of ordinary skill in the art will recognize that other ranges of coating thickness and coating variations within the above explicit ranges are contemplated and within the scope of the present disclosure.

[0082] The coating process itself can cause the evaporation of the part of solvent due to the formation of droplets or other forms of coating materials with large surface area and / or solution movement that promotes evaporation. Along with the concentration of material in the material, the loss of solvent tends to increase the viscosity of the coating material. The target during the coating process can be to remove enough solvent to stabilize the coating material, thereby for further processing. The reactive species can be condensed to form the hydrolyzate coating material during the coating period or during subsequent heating.

[0083] Typically, prior to radiation exposure, the coating material may be exposed to atmospheric moisture and optionally heated in atmospheric moisture to hydrolyze hydrolyzable bonds bonded to the metal in the precursor composition, and / or further drive off solvent and promote densification of the coating material. The coating material after in-situ hydrolysis may typically form a polymeric metal oxyhydroxy network based on bonding oxyhydroxy ligands to a metal (which also has some alkyl ligands), or a molecular solid consisting of a polynuclear metal oxy / hydroxy species with alkyl ligands.

[0084] The hydrolysis / solvent removal process may or may not be quantitatively controlled with respect to the precise stoichiometry of the heated coating material and / or the specific amount of solvent retained in the coating material. Additionally, the chemical formulas and compositions expressed herein may contain some additional water, whether directly bonded to Sn or as a hydrogen bonding component of the network. The properties of the resulting coating material can generally be empirically evaluated to select processing conditions that are effective for the patterning process. Although heating may not be required for the successful application of the process, it is desirable to heat the coated substrate to accelerate the process and / or increase the reproducibility of the process and / or promote the evaporation of hydrolysis byproducts (such as amines and / or alcohols). In embodiments in which heat is applied to remove the solvent, the coating material may be heated to a temperature of about 45°C to about 250°C, and in other embodiments, about 55°C to about 225°C. The heating for removing the solvent can generally be performed for at least about 0.1 minutes; about 0.5 minutes to about 30 minutes in other embodiments; and about 0.75 minutes to about 10 minutes in other embodiments. Those of ordinary skill in the art will recognize that other ranges of heating temperatures and times within the explicit ranges above are contemplated and within the scope of the present disclosure. As a result of thermally treating, hydrolyzing, and densifying the coating material, the coating material may exhibit an increase in refractive index and radiation absorbance without significant loss of contrast.

[0085] As demonstrated, a series of R n S X (4-n)Compounds wherein n=0, 1 or 2 or combinations thereof are hydrolyzed in solution or in situ as discussed herein to produce organotin oxide hydroxide photoresists. Useful X ligands include alkylamido and dialkylamido, chloro, alkoxy or alkynylamido, siloxy, silylamido, disilylamido, aryloxy, azido, amidato, amidinato or fluorinated analogs thereof, and substituted and unsubstituted hydrocarbyl R groups including straight and branched chain alkyl, cycloalkyl, aryl, alkenyl, alkynylbenzyl, and fluorinated derivatives thereof. For example, suitable precursors may include (CH3)3CSn(NMe2)3, (CH3)2CHSn(NMe2)3, (CH3)2(CH3CH2)CSn(NMe2)3, (CH2)2CHSn(NMe2)3, CH3Sn(NMe2)3, (CH2)3CHSn(NMe2)3, (CH2)4CHSn(NMe2)3, (C6H5)CH2Sn(NMe2)3, (C6H5)(CH3)CHSn(NMe2)3, (C6H5)(CH3)CHSn(NMe2)3, (C6H5)(CH3)CHSn(NMe2)3, (CH3)2(CN)CSn(NMe2)3, (CH3)(CN)CHSn(NMe2)3, or ( (CH3)3CSn(OtBu)3, (CH3)2CHSn(OtBu)3, (CH3)2(CH3CH2)CSn(OtBu)3, (CH2)2CHSn(OtBu)3, CH3Sn(OtBu)3, (CH2)3CHSn(OtBu)3, (CH2)4CHSn(OtBu)3, (C6H5)CH2Sn(OtBu)3, (C6H5)(CH3)CHSn(OtBu)3, (C6H5)(CH3)CHSn(OtBu)3, (C6H5)(CH3)CHSn(OtBu)3, (CH3)2(CN)CSn(OtBu)3, (CH3)(CN)CHSn(OtBu)3, or other precursors known to those skilled in the art. In addition, one or more n = 0 precursor compounds (such as Sn (NMe2) 4, or Sn (OtBu) 4) can be reacted sequentially or simultaneously with the precursor containing organic tin to change the R: Sn ratio in the film to obtain the desired patterning properties. In summary, a more general discussion of suitable R groups can be found in the discussion of organic tin triamines (alkyl acylamino) and organic tin trialkoxides (alkoxy), and these R groups can be similarly applied to the more general hydrolyzable groups discussed herein.

[0086] Defect Analysis

[0087] Unpatterned defect rates can usually be evaluated by measuring how many particles are observed on or in the deposited layer. In order to analyze non-patterned defects, the wafer is usually analyzed after the photoresist coating is deposited. The measurement of unpatterned wafer defects can be completed by using commercially available tools designed for this task (for example, Surfscan SP5 tools manufactured by KLA Tencor). For some measurements that utilize optical scattering methods to measure defects, the different wavelengths and intensities used by the light source can be converted into different measurement sensitivities for defect size ranges. It is usually desirable to use laser conditions that produce the highest sensitivity, but will not adversely affect the photoresist (for example, due to causing undesirable light damage).

[0088] For specific defect measurements on an unpatterned wafer with an organometallic radiation patternable composition, the defect measurements may be referenced relative to a Surfsacn SP5 tool operating in high sensitivity mode, with a maximum laser power setting of 2.5%, a defect size cutoff of 0.048 μm, and the spatial analysis setting turned on to filter out noise. One of ordinary skill in the art will be able to generalize these specific settings for the tool to make equivalent measurements on other tools, such as future generations of the same product. In some embodiments, the number of defects measured by excluding a 3 mm edge may be no more than about 1 defect per square centimeter; in further embodiments no more than about 0.8 defects per square centimeter; in yet other embodiments no more than about 0.7 defects per square centimeter; and in other embodiments no more than about 0.5 defects per square centimeter. One of ordinary skill in the art will recognize that other ranges of defects per unit area within the above specific ranges are contemplated and within the scope of the present disclosure.

[0089] Example

[0090] Example 1: Filtration system with impeller pump or diaphragm pump

[0091] This example demonstrates that a filtration system with an impeller pump is more effective and efficient in reducing the particle count of an organometallic photoresist solution than a filtration system with a diaphragm pump.

[0092] In this example, a comparative filtration system was assembled to examine the effect of pump type on particle counts of an organometallic photoresist solution. For both systems, the organometallic photoresist solution was a 0.044 M (based on tin concentration) solution of t-BuSn(Ot-amyl)3 in 4-methyl-2-pentanol prepared as described in Example 2 of the '498 application cited above. Filtration of the monoalkyltin trialkoxide solution was initiated immediately after dilution.

[0093] During filtration, liquid particle counts were monitored using an in-line RIONKS-41B laser system including a syringe sampler (KZ-31W) and a controller (KE-40B1). This system quantifies the number of particles of selected channel sizes to sizes as small as 70 nm via a light scattering method. The final filtered material was bottled into Aicello CB bottles in a laminar flow cleanroom hood.

[0094] Part A: Impeller Pumps

[0095] exist Figure 4 A filtration system with an impeller pump is schematically shown in FIG. The mixing tank system 200 includes five connection ports at the top of the tank. These ports allow the following processes: filtration via recirculation (ports 202, 204), tank cleaning via a spray ball (port 206), argon injection (port 208), and top space pressure monitoring (port 210). The filtration circuit consists of two magnetically suspended impeller pumps 212, 214 in series, a temperature probe, a filter 216, pressure sensors 218 and 220 before and after the filter 216, respectively, and a particle counting manifold 222. Appropriate clean pipes connect these components. A 5 nm Entegris Microgard TM UC filter.

[0096] The solution was recirculated for one day to achieve 17 volume turnovers through the filter. The particle counts for the 70 nm, 150 nm, and 200 nm channels were 3.80 / mL, 0.24 / mL, and 0.12 / mL, respectively. Table 1 summarizes the counts for all channels.

[0097] Table 1

[0098]

[0099] Filtration using an impeller pump was very effective in removing particles to small sizes. The smallest channel (70 nm) showed the most particles (3.8). The particle count decreased as the particle size increased. No particles with a size of 300 nm to 500 nm were detected.

[0100] Part B: Diaphragm Pumps

[0101] A filtration system with a diaphragm pump is similar to Figure 4 , except that a 20 L NowPak container equipped with a recirculation cap (instead of the mixing tank system 200) and an electric diaphragm pump (Cole-Parmer PTFE-Diaphragm Pump, Model #7090-42) (instead of two magnetically suspended impeller pumps) were used. 5 nm Entegris Microgard TM UC filter.

[0102] The solution was recirculated for approximately two days to achieve 28 volume turnovers through the filter. The particle counts for the 70 nm, 150 nm, and 200 nm channels were 34.2 / mL, 2.40 / mL, and 1.44 / mL, respectively. Table 2 summarizes the counts for all channels.

[0103] Table 2

[0104]

[0105] The smallest channel (70 nm) showed the most particles (34.24), which is about 9 times the number of particles measured for the solution filtered using the impeller pump. As with the impeller pump, the particle count decreases as the particle size increases. However, in the case of the diaphragm pump filtration system, the largest particles (300 nm to 500 nm) remain in the filtered solution.

[0106] Comparison of the data in Table 1 with the data in Table 2 shows that filtration with an impeller pump is more effective than filtration with a diaphragm pump. For the system with the impeller pump, the particle count for each channel size is lower. No particles of the largest size (300nm to 500nm) were observed in the solution filtered with the system with the impeller pump. The sum of particles for all channels of the impeller pump system was 7.28 and the sum of particles for all channels of the diaphragm pump system was 70.48. The results for the impeller pump system were collected after 17 volume turnovers through the filter, while the results for the diaphragm pump system were collected after 28 volume turnovers through the filter.

[0107] Example 2: Filtration loop

[0108] This example illustrates particulate removal achieved by filtering through a filter loop.

[0109] Part A: Preparation of Photoresist Precursor Solution A

[0110] A liquid blend of 20 wt% MeSn(OtAm)3 and 80 wt% tBuSn(OtAm)3 was prepared in a 4 L container in a glove box. The blend was then dispensed into an inert tank by an argon pressure device to provide about 3.50 kg of tin material in the tank. Additional tanks were filled with 4-methyl-2-pentanol (FujiFilm) and mixed with highly purified water to provide a solvent solution with a selected water content. Each tank was then connected to a controlled dispensing system leading to a mixing tank for a specific filtration system.

[0111] A large amount of 4-methyl-2-pentanol is introduced into a mixing tank. The water concentration of a large amount of 4-methyl-2-pentanol is measured. Based on the measured value, a controlled amount of 1.5wt% aqueous solvent solution is added to a large amount of 4-methyl-2-pentanol to obtain a 4-methyl-2-pentanol batch solvent with a desired water content of 200ppm to 2000ppm. The total water content of the batch solvent is measured using a KF titration unit. The uniform amount of water used in the preparation of the resist is described in the published U.S. patent application 2019 / 0391486 entitled "Stable Solutions of Monoalkyl Tin Trialkoxides and Their Hydrolysis and Condensation Products" by Jiang et al., which is incorporated herein by reference.

[0112] After the desired water content of the solvent was met, an inert argon gas was used to charge the blend of tin materials into a mixing tank.

[0113] Part B: Purification and bottling of photoresist precursor solution A

[0114] Immediately after dilution, start using Figure 4 A batch of photoresist precursor solution A was filtered using the resist purification system schematically shown in Example 1. The purification system was essentially as described in Part A of Example 1, but a 20-gallon mixing tank was used instead of a 55-gallon mixing tank. The resist was loaded into the mixing tank along with a large amount of solvent (4-methyl-2-pentanol) from a container using a clean dip tube and argon pressure. Water was added using a syringe to achieve the target solvent water content. For this example, a 1 nm Entegris Microgard TM UC Filters. Prior to the filtration cycle, the filters were cleaned by flushing with a cleaning solvent until the flushing solvent had a Sn concentration of <10 ppm (measured by ICP-MS).

[0115] The photoresist precursor solution was recirculated through the filtration loop until approximately 40 volume turnovers through the filter were achieved. The recirculation period was two days. During filtration, the liquid particle count (LPC) was monitored using an in-line RION KS-41B laser system including a syringe sampler (KZ-31W) and a controller (KE-40B1). Table 3 shows the liquid particle count for each channel of photoresist A in the pipeline after single-loop filtration as described above.

[0116] Table 3

[0117] Particle size 70nm 150nm 200nm Counts / mL 1.5 0.0 0.0

[0118] Filtration using the filtration loop was very effective in removing particulates. Only the smallest channel (70 nm) had measurable levels of particulates. No particulates were detected in the 150 nm or 200 nm channels. The total average particle count of the in-line filtered photoresist precursor solution A in the three channels was less than 1.5 counts / mL.

[0119] After the above-mentioned single-loop filtration and LPC measurement, the filtered photoresist precursor solution A was filled into a 1-gallon clean barrier bottle manufactured by Aicelol in an argon glove box environment. After bottling, the liquid particle count of the bottled and filtered photoresist precursor solution A was measured using a RION KS-41B laser system, a syringe sampler and a controller. Table 4 shows the average liquid particle count in the bottle of each channel, where the average is calculated based on 10 measurements at 2 minute intervals.

[0120] Table 4

[0121] Particle size 70nm 150nm 200nm Counts / mL 35.4 5.72 2.36

[0122] The liquid particle counts per channel were higher for the bottled solution than for the in-line solution after filtration. Particles were also detected in the 150 nm and 200 nm channels. The overall average particle count for the bottled and filtered photoresist precursor solution A in the three channels was about 44 counts / mL. It is believed that the significant increase in the measured "particles" may be due, at least in part, to bubbles generated during the bottling process, and may be to a significant degree.

[0123] Example 3: Continuous Filtration Loop

[0124] This example illustrates the improved particulate removal achieved by filtering through two consecutive filtration loops.

[0125] Before loading into the mixing vessel, the system is sealed and purged with inert gas so that the system remains sealed from the environment throughout the filtration process. Figure 2 The dual track resist purification system schematically shown in FIG. 1 begins filtering a batch of photoresist precursor solution A prepared according to Example 2. In the first filtration loop, the first filter 268 is a 1 nm Entegris Microgard TM UC filter. The photoresist precursor solution is recirculated through the first filtration loop until approximately 44 volume turnovers through the first filter are achieved. The solution is then transferred to container 292 and recirculated through the second filtration loop to perform a second filtration. In the second filtration loop, the second filter 308 is a 1 nm Entegris MicrogardTM UC filter. The photoresist precursor solution was recirculated through the second filtration loop until 38 volume turnovers through the second filter were obtained.

[0126] Liquid particle counts (LPC) were monitored during filtration using an in-line RION KS-41B laser system including a syringe sampler (KZ-31W) and controller (KE-40B1). Table 5 shows the liquid particle counts per channel of photoresist A in-line after double loop filtration as described above.

[0127] Table 5

[0128] Particle size 70nm 150nm 200nm Counts / mL 0.24 0.0 0.0

[0129] Filtration using two consecutive filtration loops was very effective in removing particulates. Only the smallest channel (70 nm) had measurable levels of particulates. No particulates were detected in the 150 nm or 200 nm channels. The total average particle count of filtered photoresist precursor solution A in the pipeline in the three channels was 0.24 counts / mL.

[0130] After the above-mentioned double loop filtration and LPC measurement, the filtered photoresist precursor solution A was filled into a 1-gallon clean barrier bottle manufactured by Aicelol using a bottling machine manufactured by Nagata (model #NUCFC-1S) equipped with an argon injection nozzle in a Class 100 clean room environment. After bottling, the liquid particle count of the bottled and filtered photoresist precursor solution A was measured using a RION KS-41B laser system, a syringe sampler and a controller. Table 6 shows the average liquid particle count in the bottle of each channel, where the average is calculated based on 10 measurements at 2 minute intervals.

[0131] Table 6

[0132] Particle size 70nm 150nm 200nm Counts / mL 22.3 2.64 0.24

[0133] Compared to the in-line solution after filtration, the liquid particle counts per channel were higher for the bottled solution. Particles were also detected in the 150nm and 200nm channels. The total average particle counts for the bottled and filtered photoresist precursor solution A in the three channels were less than 26 counts / mL.

[0134] Comparing the results of this example with those of Example 2, the in-line particle count was 1.5 counts / mL, while the continuous filtration process had a particle count of 0.24 counts / mL or a reduction of about 625%. The bottled and filtered resist particle count was 44 counts / mL, while the continuous filtration process had a particle count of 26 counts / mL or a reduction of about 170%. The results also show that lower in-line particle counts correlate with lower particle counts after bottling.

[0135] Example 4: Low-defect coating

[0136] This example illustrates the formation of a photoresist coating with a low count of unpatterned wafer (NPW) defects.

[0137] Unless otherwise stated, coatings were prepared in this example using different batches of photoresist precursor solution A prepared according to Example 2. Each coating was formed by spin coating the respective precursor solution at 1394 rpm to form a coating with a target dry thickness of 22 nm + / - 1.0 nm.

[0138] NPW defect analysis was performed on a KLA Tencor SURFCAN SP5 instrument configured to count all defects 48 nm and larger in size except for 1 cm edge exclusion in dark field inspection mode. The SP5 protocol was used in the NPW defect analysis and is described in the specification.

[0139] Part A: Coating of [commercial] organometallic photoresist on SOKUDO track

[0140] In Part A, the organometallic photoresists analyzed were manufactured by Inpria and identified as Sample 1, Sample 2 (prepared from 10 wt % iPrSn(OtAm)3+90 wt % tBuSn(OtAm)3 precursor solution), and Sample 3 (prepared from iPrSn(OtAm)3 precursor solution). TM The photoresist installation was performed on the coating track. After verifying the line cleanliness, a 1-gallon bottle of photoresist was installed on the track. After installation, 1 L of resist solution was purged through the line before depositing the film. The film was deposited on a 300 mm clean and bare silicon wafer by spin coating at 1800 rpm for 20 seconds. The coated wafer was then baked at 100°C for 60 seconds before analysis.

[0141] NPW defect analysis was performed on three different organometallic photoresist coatings and the results are shown in Table 7. Table 7 also shows the 679 cm 2 The defect density is calculated from the measured area.

[0142] Table 7

[0143]

[0144]

[0145] The results show that low defect counts can be achieved for a range of organometallic photoresist compositions.

[0146] Part B: Coating of bottled and filtered photoresist precursor solution A using the TEL track

[0147] In part B, use Figure 3 TEL CLEAN TRACK shown TM LITHIUS Pro TM Z coating track, bottled and filtered photoresist solution A prepared according to Example 3 was coated onto the wafer without filter 363 or container 369. After verifying the line cleanliness, a 1 gallon bottle of photoresist was installed on the track. After installation, a sample of 1L to 1.5L of the resist solution was purged through the line before depositing the film. The film was deposited on a 300mm clean and bare silicon wafer by spin coating at 1800rpm for 20 seconds. The coated wafer was then baked at 100°C for 60 seconds before analysis.

[0148] NPW defect analysis was performed on three replicate wafers and the results are shown in Table 8. Table 8 also shows the 2 Defect density calculated from the measured area. An average of 213 defects per wafer was measured.

[0149] Table 8

[0150] Chip number Defects > 48nm <![CDATA[Defects / cm 2 > 1 223 0.33 2 210 0.31 3 206 0.30 average: 213 0.31

[0151] Part C: Coating of bottled and filtered photoresist precursor solution A using the TEL track

[0152] In part C, use Figure 3 TEL CLEAN TRACK shown TM LITHIUS Pro TMZ coating track, bottled and filtered photoresist solution A prepared according to Example 2 was coated onto the wafer without filter 363 or container 369. After verifying the line cleanliness, a 1 gallon bottle of photoresist was installed on the track. After installation, a sample of 1L to 1.5L of the resist solution was purged through the line before depositing the film. The film was deposited on a 300mm clean and bare silicon wafer by spin coating at 1800rpm for 20 seconds. The coated wafer was then baked at 100°C for 60 seconds before analysis.

[0153] NPW defect analysis was performed on three replicate wafers and the results are shown in Table 9. Table 9 also shows the 679 cm 2 Defect density calculated from the measured area. An average of 357 defects per wafer were measured.

[0154] Table 9

[0155] Chip number Defects > 48nm <![CDATA[Defects / cm 2 > 1 360 0.53 2 361 0.53 3 349 0.51 average: 357 0.53

[0156] The results of Sections B and C show that lower particle counts of bottled photoresist solutions provide lower coating defects. Thus, lower in-line liquid particle counts correlate to lower coating defects.

[0157] Part D: Coating of Bottled and Filtered Photoresist Precursor Solution A Using a Filtered TEL Track Line

[0158] In Part D, the bottled and filtered photoresist solution A is filtered using the dual track resist purification system according to Part B of Example 3. Figure 3 TEL CLEAN TRACK shown in TM LITHIUS Pro TM Z coating track, different batches of solution (1U, 2U, 3U and 4F) were each coated onto multiple wafers. Batches 1U, 2U and 3U were coated onto wafers without filter 363 or container 369. Batch 4F was coated onto wafers at 1 nm Entegris Microgard TM The UC filter was coated onto the wafer after being installed at filter 363. After verifying the line cleanliness, a 1 gallon bottle of photoresist was installed on the rail. After installation, a sample of 1L to 1.5L of resist solution was purged through the line before depositing the film. The film was deposited on a 300mm clean and bare silicon wafer by spin coating at 1800rpm for 20 seconds. The coated wafer was then baked at 100°C for 60 seconds before analysis.

[0159] NPW defect analysis was performed on each batch and the average number of defects per wafer for each batch is shown in Table 10. Table 10 also shows the average number of defects per wafer based on 679 cm 2 The average defect density is calculated from the measured area.

[0160] Table 10

[0161] batch Chip number Average defect >48nm <![CDATA[Average defect / cm 2 > 1U 6 159 0.23 2U 3 213 0.31 3U 3 137 0.20 4F 3 78 0.11

[0162] The average NPW defectivity of wafers coated using batches 1U-3U was about 170 defects per wafer. The average NPW defectivity of wafers coated using batch 4F was 78 defects per wafer. Placing the filter near the delivery nozzle of the coating track line reduced the NPW coating defects by a factor of 2 or more. This example shows that combining a filter located near the delivery nozzle of the wafer track line with dual loop filtration of the coating solution can provide a coating with less than 100 non-patterned wafer defects per wafer.

[0163] Part E: Coating of Bottled and Filtered Photoresist Precursor Solution A Using a Filtered TEL Track Line

[0164] In Part E, the bottled and filtered photoresist solution A is filtered using the dual track resist purification system according to Part B of Example 3. Figure 3 TEL CLEAN TRACK shown in TM LITHIUS Pro TM Z coating track, 6 different batches of solution A (AF) are coated onto the wafer without container 369. Filter 363 is 5 nm Series of photochemical filters. After verifying the cleanliness of the lines, a 1-gallon bottle of photoresist was mounted on the rail. After mounting, a sample of 1 L to 1.5 L of resist solution was purged through the lines before depositing the film. The film was deposited on a 300 mm clean and bare silicon wafer by spin coating at 1800 rpm for 20 seconds. The coated wafer was then baked at 100°C for 60 seconds before analysis.

[0165] NPW defect analysis was performed on each sample and the average number of defects per wafer for each sample is shown in Table 11. Table 11 also shows the average number of defects per wafer based on 679 cm 2 The defect density is calculated from the measured area.

[0166] Table 11

[0167] batch Defects > 48nm <![CDATA[Defects / cm 2 > A 78 0.11 B 64 0.09 B 40 0.06 B 39 0.06 B 30 0.04 C 44 0.06 D 48 0.07 D 96 0.14 E 86 0.13 E 39 0.06 E 68 0.10 F 66 0.10 average: 58 0.09

[0168] The average NPW defectivity was 58 defects per wafer, and there were no wafers with more than 100 defects. This example also shows that low NPW defects can be achieved by combining filters located near the delivery nozzles of the wafer track line with dual loop filtration of the coating solution.

[0169] Additional Inventive Concepts

[0170] 1. A method for forming an organometallic resist composition having low particulate contamination, the method comprising:

[0171] circulating an organometallic resist composition from a first mixing vessel having an inlet and an outlet on a first filter loop through a first filter using an impeller pump to remove particulate contaminants to form a first filtered composition;

[0172] directing the first filtration composition to a second filtration loop, the second filtration loop comprising a second mixing vessel;

[0173] using an impeller pump, circulating the first filter composition in a second filter loop through a second filter to remove particulate contaminants to form a second filter composition until the second filter composition reaches a purification parameter, the purification parameter comprising a particulate concentration below a design level, a volume transfer through the filter above a design level, or a combination thereof;

[0174] wherein the particle concentration is measured in-line in a closed system substantially free of air bubbles;

[0175] placing the filtered organometallic resist composition into a container within the clean room, wherein flow is directed from the branch valve along the second filter loop; and

[0176] The container within the clean room is sealed.

[0177] 2. The method according to inventive concept 1, wherein the second filter composition has a particle concentration measured by light scattering of less than 10 particles / mL at a size of at least 70 nm.

[0178] 3. The method according to inventive concept 1, wherein the second filter composition has a particle concentration measured by light scattering of less than 4 particles / mL at a size of at least 70 nm.

[0179] 4. The method according to inventive concept 1, wherein the number of volume transfers through the first filter circuit and the number of volume transfers through the second filter circuit are independently 2 to 100.

[0180] 5. The method according to Inventive Concept 1, wherein the first filter and / or the second filter is a semiconductor-grade filter with an exclusion size of <5 nm.

[0181] 6. The method according to inventive concept 1, wherein the first filter circuit and / or the second filter circuit further comprises one or more additional filters and / or one or more additional impeller pumps.

[0182] 7. The method according to Inventive Concept 1, wherein the container is made of high-density polyethylene (HDPE), polytetrafluoroethylene (PTFE) or polypropylene (PP).

[0183] 8. The method according to Inventive Concept 1, wherein the first mixing container and / or the second mixing container is provided with argon gas.

[0184] 9. The method according to inventive concept 1, wherein the organometallic resist composition comprises a monoalkyltin trialkoxide, a monoalkyltintriamine, or a combination thereof in an organic solvent at a concentration of about 0.0025 M to about 1.4 M based on tin.

[0185] 10. An apparatus for removing particles from an organometallic resist composition, the apparatus comprising:

[0186] a. a first flow circuit, the first flow circuit comprising a mixing container having an inlet and an outlet, a first impeller pump, a first filter and a conduit for connecting the elements in a closed loop, the first flow circuit being configured for the first impeller pump to direct flow through the first filter along a path from the inlet to the outlet to remove particulate contaminants;

[0187] b. a second flow circuit comprising a mixing vessel having an inlet and an outlet, a second impeller pump, a second filter, and conduits for connecting the elements in a closed loop, the second flow circuit being configured for the second impeller pump to direct flow through the second filter along a path from the inlet to the outlet to remove particulate contaminants;

[0188] c. a connecting line comprising a valve and a flow conduit, the connecting line being configured to provide flow between the first flow circuit and the second flow circuit;

[0189] d. a distribution line connected to the second flow circuit, the distribution line comprising a valve and a flow conduit, the distribution line being configured to distribute the filtered resist composition from the second flow circuit within the clean room.

[0190] 11. The apparatus according to inventive concept 10, further comprising a distribution line connected to a bottling unit in a bottling room in the clean room, wherein the FS209E grade of the bottling room is at least 1000 and the FS209E grade of the clean room is at least 100.

[0191] 12. The apparatus of inventive concept 10, wherein the first flow loop and the second flow loop further comprise a gas inlet into the container, an in-line particle analyzer, and a flow meter.

[0192] 13. A composition comprising a solvent and an organotin composition having a tin concentration of about 0.005 M to about 0.5 M and no more than about 4 particles / mL when the particle size is at least about 70 nm as measured in a closed system substantially free of bubbles.

[0193] 14. The composition according to inventive concept 13, wherein the solvent comprises an organic solvent, and the organotin composition comprises a compound of the formula RSn(OR 0 )3, a monoalkyltin trialkoxide represented by the formula RSn(NR′)3, a monoalkyltin triamine represented by the formula RSn(NR′)3, or a combination thereof,

[0194] wherein R is an alkyl or cycloalkyl group having 1 to 31 carbon atoms, one or more carbon atoms being optionally substituted with one or more heteroatom functional groups containing O, N, Si, Ge, Sn, Te and / or hydrogen atoms or a combination thereof, or an alkyl or cycloalkyl group having 1 to 31 carbon atoms further functionalized with phenyl or cyano groups or a combination thereof,

[0195] Among them, R′ and R 0 The groups are independently hydrocarbon groups having 1 to 10 carbon atoms.

[0196] 15. The composition according to inventive concept 14, wherein R comprises methyl (CH3-), ethyl (CH3CH2-), isopropyl (CH3CH3HC-), tert-butyl ((CH3)3C-), tert-pentyl (CH3CH2(CH3)2C-), sec-butyl (CH3(CH3CH2)CH-), neopentyl ((CH3)3CCH2-), cyclohexyl, cyclopentyl, cyclobutyl, benzyl, allyl or cyclopropyl, or a combination thereof, wherein R 0 Includes one or more branched alkyl ligands.

[0197] The above embodiments are intended to illustrate rather than limit. Other embodiments are also within the scope of the claims. In addition, although the present invention has been described with reference to specific embodiments, those skilled in the art will recognize that changes can be made in form and detail without departing from the spirit and scope of the present invention. Any introduction by introducing documents hereinabove is limited so that no subject matter contrary to the explicit disclosure herein is introduced. With respect to the specific structures, compositions and / or processes described herein as parts, elements, components or other parts, it should be understood that unless otherwise expressly indicated, the disclosure herein covers specific embodiments, including embodiments of specific parts, elements, components, other parts or combinations thereof, and embodiments consisting essentially of such specific parts, components or other parts or combinations thereof, which embodiments may include other features that do not change the basic properties of the subject matter as suggested in the discussion.

Claims

1. A wafer structure, comprising: a substrate and a radiation-sensitive organometallic coating having an average thickness of no more than 100 nm and having no more than 1 defect per square centimeter when evaluated for defects greater than 48 nm in size, excluding a 3 mm edge, wherein the radiation-sensitive organometallic coating comprises a monoalkyltin composition formed by depositing a hydrolyzable precursor composition, the hydrolyzable precursor composition comprising a composition represented by the formula RSnX3 and having no more than 10 particles / mL when the particle size is at least 70 nm, and wherein the wafer structure has a smooth top surface, Wherein, the radiation-sensitive organic metal coating, when fully hydrolyzed, comprises a polymer of the formula RSnO (1.5-(n / 2)) (OH) n A composition represented by, wherein 0<n≤3, wherein R is an organic ligand having 1 to 31 carbon atoms, wherein the carbon atom is bonded to Sn, and wherein X is a hydrolyzable ligand.

2. The wafer structure of claim 1, wherein R is an organic ligand having one or more carbon atoms substituted with one or more heteroatom functional groups.

3. The wafer structure according to claim 1, comprising: A silicon wafer, a silicon dioxide substrate, a ceramic material, a polymer substrate, or a combination thereof across a surface of the substrate and / or in a layer of the substrate. The wafer structure according to claim 1 , comprising a silicon wafer.

5. The wafer structure according to claim 1, wherein: The radiation-sensitive organometallic coating includes a plurality of R groups of different chemical structures.

6. The wafer structure according to claim 1, wherein: R is an alkyl group or a cycloalkyl group having 1 to 10 carbon atoms.

7. The wafer structure according to claim 1, wherein: R is composed of R 1 R 2 R 3 C-represented branched alkyl ligand, where R 1 and R 2 are independently an alkyl group having 1 to 10 carbon atoms, R 3 is hydrogen or an alkyl group having 1 to 10 carbon atoms.

8. The wafer structure according to claim 1, wherein: R includes methyl (CH3-), ethyl (CH3CH2-), isopropyl (CH3CH3HC-), tert-butyl ((CH3)3C-), tert-pentyl (CH3CH2(CH3)2C-), sec-butyl (CH3(CH3CH2)CH-), neopentyl ((CH3)3CCH2-), cyclohexyl, cyclopentyl, cyclobutyl, benzyl, allyl or cyclopropyl.

9. The wafer structure according to claim 1, wherein: The hydrolyzable precursor composition includes monoalkyltintrialkoxide, monoalkyltintriamine, or a combination thereof.

10. The wafer structure according to claim 1, wherein: The radiation-sensitive organometallic coating has an average thickness of no more than 50 nm.

11. The wafer structure of claim 1 having no more than 0.5 defects per square centimeter when evaluated for defects larger than 48 nm in size, excluding a 3 mm edge.

12. The wafer structure of claim 1 having no more than 0.2 defects per square centimeter when evaluated for defects larger than 48 nm in size, excluding a 3 mm edge.

13. The wafer structure according to claim 1, wherein: The coating has metal contamination in the parts per billion range and no more than 2 wt % polyalkyl tin oxide hydroxide contamination.

14. The wafer structure according to claim 1, wherein: The hydrolyzable precursor composition is hydrolyzed during deposition of the precursor composition on the substrate and / or after deposition of the precursor composition on the substrate.

15. The wafer structure according to claim 1, wherein: The radiation-sensitive organometallic coating includes a polymerized metal oxyhydroxy network.

16. The wafer structure according to claim 1, wherein: The radiation-sensitive organometallic coating has no more than 2 wt % polyalkyltin oxide hydroxide contamination.

17. The wafer structure according to claim 1, wherein: The radiation-sensitive organometallic coating has an average thickness of 1 nm to 50 nm.

18. The wafer structure according to claim 1, wherein: The hydrolyzable precursor composition is deposited under conditions that limit contact with water in a delivery line between a container including the hydrolyzable precursor composition and a delivery nozzle.

19. The wafer structure according to claim 18, wherein: Prior to the deposition, the delivery line from the container to the delivery nozzle is flushed first with a solvent and then with a quantity of purified resist.

20. The wafer structure according to claim 19, wherein: The delivery line includes a filter proximate the delivery nozzle.

21. The wafer structure according to claim 1, wherein: The depositing includes spin coating.

22. A method for forming a low defect coating, the method comprising: spin coating the purified radiation-sensitive organometallic resist precursor solution onto a wafer to form a coated wafer using a spin coater system, the spin coater system comprising a delivery line and a delivery nozzle connected to the delivery line, wherein the organometallic resist precursor solution comprises a hydrolyzable precursor composition, the hydrolyzable precursor composition comprises a composition represented by the formula RSnX3, wherein R is an organic ligand having 1 to 31 carbon atoms, wherein the carbon atom is bonded to Sn, and wherein X is a hydrolyzable ligand, and wherein the organometallic resist precursor solution has a tin concentration of 0.01 M to 0.25 M, and has been filtered to contain no more than 10 particles / mL in the case of a particle size of at least 70 nm, and the organometallic resist precursor solution is delivered from a container connected to the delivery line, wherein particulate impurities are measured in a closed filtration system in the substantial absence of bubbles, and wherein the delivery of the organometallic resist precursor solution is performed under conditions that limit water contact between the container and the delivery nozzle; and drying the coated wafer to form a radiation-sensitive organometallic coating comprising a monoalkyltin composition and having no more than 1 defect per square centimeter when evaluated for defects greater than 48 nm in size, excluding a 3 mm edge; wherein the radiation-sensitive organometallic coating, when fully hydrolyzed, comprises (1.5-(n / 2)) (OH) n A composition represented by wherein 0<n≤3.

23. The method according to claim 22, wherein: R is an organic ligand having one or more carbon atoms substituted with one or more heteroatom functional groups.

24. The method according to claim 22, wherein: Before performing the spin coating, the delivery line from the container to the delivery nozzle is flushed first with a solvent and then with a certain amount of purified resist.

25. The method according to claim 22, wherein: The transfer line includes a filter designed to remove particles with a size greater than 3 nm.

26. The method of claim 22, wherein: The delivery line includes a filter located at or near the delivery nozzle.

27. The method according to claim 24, wherein: The amount of cleaned resist before performing the spin coating is at least 5 ml and at least once every 60 minutes.

28. The method of claim 24, wherein: The amount of cleaned resist before performing the spin coating is at least 3 ml and at least once every 30 minutes.

29. The method of claim 22, wherein: The container is made of high-density polyethylene (HDPE), polytetrafluoroethylene (PTFE) or polypropylene (PP).

30. The method of claim 22, wherein: The organometallic resist precursor solution has been filtered to contain no more than 4 particles / mL.

31. The method of claim 22, wherein: The hydrolyzable precursor composition includes monoalkyltintrialkoxide, monoalkyltintriamine, or a combination thereof.

32. The method of claim 22, wherein: The radiation-sensitive organometallic coating has no more than 0.5 defects per square centimeter when evaluated for defects greater than 48 nm in size, excluding a 3 mm edge.

33. The method of claim 22, further comprising exposing the coated wafer to atmospheric moisture to form a polymerized metal oxyhydroxy network.

34. The method of claim 33, wherein: The coated wafer is exposed to atmospheric moisture during heating to form a polymerized metal oxyhydroxy network.

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