TWI495951B - Ultra-thin polymeric adhesion layer - Google Patents

Description

Ultra-thin polymerizable adhesive layer Cross-references to related applications

This patent application claims the benefit of U.S. Patent Provisional Application Serial No. 60/992,179, filed on Dec. 4, 2007, which is hereby incorporated by for reference. U.S. Patent Application Serial Nos. 11/187,406 and 11/187,407, filed on July 22, 2005, and U.S. Patent Application Serial No. Part Continuation of the Application is incorporated herein by reference. U.S. Patent Application Serial No. 11/734,542 is a continuation-in-part of U.S. Patent Application Serial Nos. 11/187,406 and 11/187,407.

Affirmation of federal government awards for research or development

The U.S. government has a free license for this invention and, in limited circumstances, restricts the patentee’s right to grant permission to use the license under the reasonable conditions of the 70th NNB4H3012 issued by the National Institute of Standards (NIST).

Field of invention

The field of the invention generally relates to a nano process of construction. More specifically, the present invention relates to an ultrathin polymerizable adhesive layer.

Background of the invention

The nanometer process includes a process of extremely small structure having a feature of 100 nm or less. The nanometer process that has been greatly affected by the application is the processing of the integrated circuit. The semiconductor processing industry continues to strive for higher yields while increasing the number of circuits formed per unit area on the substrate, so the nanometer process becomes more important. The nanometer process provides better process control while allowing for a continuous reduction in the minimum feature size that forms the structure. Nanotechnology developed in other fields has been applied to biotechnology, optical technology, mechanical systems, and the like.

An exemplary nanofabrication technique currently in use is commonly referred to as imprint lithography. An exemplary embossing lithography process has been described in detail in a number of documents, for example, U.S. Patent Application Publication No. 2004/0065976, U.S. Patent Application Publication No. 2004/006525, and U.S. Patent No. 6,936,194 for reference.

Imprint lithography, which is disclosed in the above-mentioned U.S. Patent Application Publications and patents, respectively, discloses the formation of a embossed pattern in a moldable (polymeric) layer and the transfer of a pattern corresponding to the embossed pattern to an underlying substrate. The substrate is placed on a mobile station in an adjustable position to facilitate the patterning process. The patterning process utilizes a template spaced from the substrate and a molding solution applied between the template and the substrate. The forming liquid is cured to form a rigid layer having a pattern conforming to the shape of the surface of the template contacting the forming liquid. After curing, the template and substrate are separated by separating the template and the rigid layer. Another process of the substrate and the cured layer is then performed to transfer the relief image into the substrate corresponding to the pattern in the cured layer.

Summary of invention

In one aspect, an imprint lithography imprint stack includes a substrate and a polymeric adhesive layer attached to the substrate. In another aspect, an adhesive layer is formed by spin coating a polymerizable composition onto an imprint lithography substrate and curing the polymerizable composition to form a polymeric adhesive layer attached to the imprint lithography substrate. It is formed on an imprint lithography substrate. The polymerizable composition comprises a polymeric component having a length of the extended polymeric backbone of at least about 2 nanometers. The backbone of the polymeric component is substantially aligned in a planar configuration on the surface of the embossed lithography substrate. The polymerizable composition is cured to form a polymerizable adhesive layer. The thickness of the polymerizable adhesive layer is less than about 2 nm.

In some embodiments, the polymeric adhesive layer has a thickness of about 1 nanometer. The polymeric adhesive layer can be formed from a composition comprising a polymeric component having a length of the polymeric backbone extending at least about 2 nanometers. In some examples, the polymeric component can be synthesized from a compound that includes an aromatic group. In certain instances, the polymeric component comprises a carboxylic acid functional group capable of bonding to a substrate and another functional group capable of binding to an imprinting photoresist. The polymeric adhesive layer can incorporate an embossed photoresist during curing of the embossed photoresist on the embossed stack.

Simple illustration

The invention will be more apparent from the following detailed description of embodiments of the invention. It is to be understood that the description of the drawings is only a typical embodiment of the invention and is not intended to

Figure 1 is a simplified plan view of the prior art;

Figure 2 is a simplified elevational view of a stencil and embossing material placed on a substrate in accordance with the present invention;

Figure 3 is a simplified elevational view of the template and substrate of the imprinting material shown in Figure 2, which has been patterned and formed into a cured layer;

Figure 4 is a cross-sectional view of a template for forming a weak boundary layer between a cured imprint material and a stencil in contact with an imprint material;

Figure 5 is a detailed view of the droplets of the imprint material shown in Figure 2, showing that the droplets are separated to form a surfactant-rich region and a surfactant-deficient region;

Figure 6 is a detailed view showing the deposition of the layer of imprinted material by spin coating to show that the layer is separated to form a surfactant-rich region and a surfactant-deficient region;

Figure 7 is a cross-sectional view of a cured imprint material template deposited on a substrate comprising a bottom layer by contact with the method of Figure 5 or 6;

Figure 8 is a chemical structural formula that can be used to form a composition of a bottom layer;

Figure 9 is a chemical structural formula that can be used to form a composition of a bottom layer;

Figure 10 is a chemical structural formula that can be used to form a composition of a bottom layer;

Figure 11 is a chemical structural formula that can be used to form a composition of a bottom layer;

Figures 12A and 12B are measurement positions for measuring the thickness of the polymeric adhesive layer;

Figure 13 is a scanning electron micrograph image of a cross-section of a germanium wafer coated with a polymerizable adhesive layer.

Detailed description of the preferred embodiment

Referring to Figures 1 and 2, a mold 36 in accordance with the present invention can be used in system 10 and can define a smooth or planar outer surface (not shown). Alternatively, the mold 36 can include a shape defined by a plurality of fixed distance indentations 38 and projections 40. The plurality of shapes are original patterns forming the basis of the pattern on the substrate 42. Substrate 42 may comprise a bare wafer or one or more wafers placed thereon, one of which is bottom layer 45. For this purpose, it can shorten the distance "d" between the mold 36 and the substrate 42. In this manner, the shape on the mold 36 can be embossed into an integrated region on which the imprint material is placed on the substrate 42 having a portion of the substantially planar profile surface 44. It will be appreciated that the imprint material can be deposited using any known technique, such as spin coating, dip coating, and the like. However, in the present example, the imprint material is deposited on the substrate 42 to form a plurality of spaced apart droplets 46. The embossed material formed is selected from a polymeric and crosslinked composition that can record the original pattern, i.e., the recorded pattern.

Specifically, the portion of the pattern recorded on the embossed material is produced by interaction with the mold 36, such as electrical interaction, magnetic interaction, thermal interaction, mechanical interaction, and the like. In the example of the present invention, the mold 36 is in mechanical contact with the embossing material to spread the droplets 46 such that the embossing material forms a tie layer 50 on the surface 44. In a specific embodiment, the distance "d" is shortened to cause the secondary segment 52 of the imprint material to enter and fill the indent 38. To facilitate filling of the indentations 38, the air between the mold 36 and the droplets 46 is filled with helium or completely evacuated or partially evacuated before the mold 36 and the droplets 46 are contacted.

The embossed material is filled into the indentations 38 while the surface 44 is covered with a tie layer of embossed material. In a particular embodiment of the invention, the sub-segments 54 of the remaining imprint material will be overlapped by the projections 40 after reaching the desired shortest desired distance "d". This action will cause the secondary section 52 of the tie layer 50 to have a thickness t1 and the secondary section 54 to have a thickness t2. The different thicknesses "t1" and "t2" depending on the application can be any desired thickness. Thereafter, the embossed material connection layer 50 can be cured by exposure to a suitable curing agent such as broadband ultraviolet light energy, thermal energy, or the like. This will result in polymerization and crosslinking of the imprinted material. This entire process can be carried out at ambient temperature and pressure, or under a controlled atmosphere having the desired temperature and pressure. In this method, the tie layer 50 is cured to create a side 56 that conforms to the shape of the surface 58 of the mold 36.

Referring to Figures 1, 2 and 3, the effective patterning of the substrate 42 is extremely important depending on the characteristics of the unique patterning process imprint material used. For example, the embossed material preferably has certain characteristics that facilitate the rapid and uniform filling of the shape of the mold 36 such that all of t1 and t2 have substantially uniform thicknesses. For this purpose, it is preferred to select the viscosity of the imprint material in accordance with the deposition method used to obtain the above characteristics. As described above, the imprint material can be deposited on the substrate 42 using a variety of techniques. If the imprint material is to be deposited as a plurality of discrete discrete droplets 46, the imprint material is preferably formed from a composition having a relatively low viscosity, for example, in the range of 0.5 to 20 centipoise (cP). Since the imprint material is simultaneously spread and patterned, and the pattern is immediately cured into the connection layer 50 by exposure to radiation, it is preferred to distribute the composition on the surface of the substrate 42 and/or the mold 36 and to avoid A pit or hole is formed after polymerization. When the imprint material is deposited by spin coating, it is preferred to use a material having a higher viscosity, for example, a viscosity of more than 10 cP and usually several hundred to several thousand cP, which is measured without a solvent.

In addition to the above characteristics, as for the liquid phase characteristics, it is preferred to use a composition which allows the imprint material to have certain curing phase characteristics. For example, the imprint material preferably has the property of preferential adhesion and release after the tie layer 50 is cured. Specifically, the composition of the imprint material is preferably a tie layer 50 that can be preferentially adhered to the substrate 42 and the preferential release mold 36. In this way, it is possible to avoid deterioration of the recording pattern particularly when peeling off, stretching to separate from the mold 36, or other construction of the connecting layer 50.

The composition forming the imprint material having the above characteristics may contain different constituent components. This will result in the need to form the substrate 42 from a number of different materials. Thus, the material forming the substrate 42 will have a different surface 44 chemical composition. For example, the substrate 42 can be formed from tantalum, plastic, gallium arsenide, mercury telluride, and composite materials thereof. As noted above, the substrate 42 can include one or more layers, such as a dielectric layer, a metal layer, a semiconductor layer, a planarization layer, and the like, as shown by the underlayer 45 on which the tie layer 50 is formed. For this purpose, the bottom layer 45 will be deposited on a wafer 47 using any suitable technique, such as chemical vapor deposition, spin coating, or the like. Additionally, the bottom layer 45 can be formed from any suitable material, such as tantalum, niobium, and the like. Further, the mold 36 may be formed from several materials such as fused, quartz, indium tin oxide diamond-like carbon, MoSi, sol gel, and the like.

It has been found that the composition that produces the tie layer 50 can be made from bulk materials of several different families. For example, some of the materials from which the composition can be made are vinyl ether, methyl acrylate, epoxy resin, thiol olefin, and acrylate.

The following are exemplary bulk materials for forming the tie layer 50:

Substrate imprint material

different Acrylate

N-hexyl acrylate

Ethylene glycol diacrylate

2-carboxylic acid-2-methyl-1-phenyl-propan-1-one

Acrylate composition, different The acrylate (IBOA) has the following structure:

And comprising a weight ratio of about 47% of the matrix material, but the content is in the range of 20% to 80%. Therefore, the mechanical properties of the tie layer 50 are primarily attributable to the IBOA. An exemplary source of IBOA is commercially available product SR506 from Sartomer Corporation of Extonln, Pa.

The n-hexyl acrylate (n-HA) component has the following structure:

And comprising about 25% by weight of the matrix material, but the total content is in the range of 0% to 50%. It also provides the flexibility of the tie layer 50, which is used to reduce the viscosity of the matrix material such that the matrix material has a viscosity in the liquid phase of less than about 10 cP. An exemplary source of the n-HA component is Aldrich Chemical Company, Milwaukee, Wisconsin.

The cross-linking component of ethylene glycol diacrylate has the following structure:

And comprising about 25% by weight of the matrix material, but the total content is in the range of 10% to 50%. EGDA can also increase modulus and stiffness, as well as facilitate cross-linking of n-HA and IBOA during polymerization of the matrix material.

Initiator component, 2-methyl-1-phenyl-2-carboxylic acid - based propan-1-one available from Ciba Specialty Chemicals Tarrytown, New York City company DAROCUR ^TM commercially available in 1173, and has the following structure:

And comprising a weight ratio of the matrix material of about 3%, but the total content is in the range of 1% to 5%. The actinic energy of the initiator reaction produces broadband ultraviolet light energy from a medium pressure mercury lamp. In this way, the initiator facilitates crosslinking and polymerization of the components of the matrix material.

A thin layer 60 of the weak boundary layer shown in Figures 3 and 4 is thus fabricated between the surface 58 of the mold 36 and the tie layer 50 as described in U.S. Patent No. 7,307,118, the disclosure of which is incorporated herein by reference. The thin layer 60 remains after the imprint material has been cured. Therefore, there is minimal adhesion between the mold 36 and the tie layer 50. For this purpose, the embossing material preferably utilizes a composition comprising one or more substrate imprinting materials such as the above-described substrate and a surfactant component having a low surface energy group.

Referring to Figure 5, after depositing the embossed material, the surfactant component is raised to the gas-liquid interface after a period of time to form droplets 146 having embossed materials of separate material concentrations. In the first part, the droplet 146 contains a higher concentration of surfactant component called a surfactant-rich component (SCR) sub-segment 136, which is then referred to as a surfactant-deficient component (SCD) sub-point. Paragraph 137. The SCD sub-segment 137 is placed between the surface 44 and the SCR sub-segment 136. The SCR sub-segment 136 can reduce the adhesion between the mold 36 and the imprint material after the imprint material is cured. Specifically, the surfactant component has opposite ends. When the imprinted material is in the polymerizable liquid phase, its opposite end has an affinity for the matrix material contained in the imprint material. The remaining ends have a fluorine component.

Referring to Figures 4 and 5, due to the affinity for the matrix material, the surfactant component is oriented such that the fluorine component extends from the gas-liquid interface defined by the imprint material and ambient air.

When the imprint material is cured, the first portion of the imprint material creates a thin layer 60 and the second portion of the imprint material is cured, i.e., the polymeric material as shown in tie layer 50. A thin layer 60 is placed between the tie layer 50 and the mold 36. The thin layer 60 is produced due to the presence and placement of fluorine components within the SCR sub-segment 136. The thin layer 60 prevents excessive adhesion between the mold 36 and the tie layer 50. In particular, the tie layer 50 has first and second opposing sides 62 and 64. The edge 62 is adhered to the mold 36 with a first adhesive force. The edge 64 is adhered to the substrate 42 with a second adhesive force. The first adhesive force produced by the thin layer 60 is lower than the second adhesive force. Thus, the mold 36 can be easily removed from the tie layer 50 while not causing deformation and/or reducing the force required to separate from the mold 36. Although the connection layer 50 having the side 62 is patterned, it should be understood that the side 62 remains smooth even if it is not flat.

Further, if desired, it can form a thin layer 60 that is placed between the tie layer 50 and the substrate 42. This can be accomplished by applying an embossing material to the mold 36 and then contacting the substrate 42 with an embossing material on the mold 36. In this manner, the tie layer 50 will be placed between the thin layer 60 and the substrate, such as the mold 36 or substrate 42 from which the polymeric material is deposited. It will be appreciated that similar separation material concentrations will occur if the imprint material is deposited by spin coating as shown in Figure 6 with SCR sub-segment 236 and second and SCD sub-segment 237. The time required to separate the concentrations depends on a number of factors, including the size of the molecules within the composition and the viscosity of the composition. It takes only a few seconds to reach the above separate composition when the viscosity is lower than 20 cp. However, if the material viscosity is several hundred cP, it may take several seconds to several minutes.

However, it has been found that the thin layer 60 may be uneven. Some regions of the thin layer 60 may be thinner than other regions, and in some extreme instances, a very small proportion of the template surface may lose the thin layer 60 such that the template 36 directly contacts the tie layer 50. The thinner layer 60 and the area where the thin layer 60 is lost may cause deformation and/or structural peeling of the connection layer 50 from the substrate 42. Specifically, the separation layer 50 must be subjected to a separation force (FS) when the mold 36 is separated. The separation force (FS) is derived from the tensile force (FP) to the mold 36 and the adhesion between the tie layer 50 and the mold 36 by the thin layer 60, such as the van der Waals force. Due to the presence of the thin layer 60, the separation force (FS) between the tie layer 50 and the substrate 42 is generally lower than the adhesion force (FA). However, if the thin layer 60 is reduced or lost, the local separation force (FS) may approach the local adhesion (FA). Locally stressed means the presence of a force in the region of a known thin layer 60, which in this example is a localized force near a thin region of the thin layer 60 or a region substantially free of the thin layer 60. This will result in deformation and/or peeling of the tie layer 50 from the substrate 42.

Referring to Figure 7, in the presence of the bottom layer 45, the situation is further complicated by the presence of two interfaces 66 and 68. The first interface 66 between the bottom layer 45 and the tie layer 50 has a first adhesive force (F1). The second interface 68 between the bottom layer 45 and the wafer 47 has a second adhesion (F2). The separation force (FS) is preferably smaller than the adhesion forces F1 and F2. However, due to differences or lacks in thickness of the thin layer 60 discussed above, the separation force (FS) may be similar or close to the adhesion forces F1 and F2 of one or both. This will result in the peeling of the tie layer 50 from the bottom layer 45, the bottom layer 45 from the wafer 47, or both.

The present invention reduces or avoids the problem of peeling by forming the bottom layer 45 by adding the first F1 and the second F2 bonding forces of the first and second interfaces to a material which is larger than the thin layer wave separation force (FS), respectively. For this purpose, the interface 66 between the bottom layer 45 and the tie layer 50 and the interface 68 between the bottom layer 45 and the wafer 47 form the bottom layer 45 using a composition having a strong bond. In the example of the present invention, the adhesion of the first interface 66 between the bottom layer 45 and the tie layer 50 is derived from a covalent bond, i.e., covalently present between the group of articles forming the bottom layer 45 and the composition forming the tie layer 50. key. The adhesion between the bottom layer 45 and the wafer 47 can be achieved by any of a variety of different mechanisms. These mechanisms include creating a covalent bond between the composition forming the bottom layer 45 and the material forming the wafer 47. Alternatively, or in addition to the covalent bond, an ionic bond is additionally formed between the composition forming the underlayer 45 and the material forming the wafer 47. Alternatively, or in addition to the covalent bond and/or the ionic bond or both, the adhesion is generated by the van der Waals force between the composition forming the underlayer 45 and the material forming the wafer 47.

This can be achieved by forming a bottom layer 45 using a composition comprising a multifunctional reactive compound, i.e., the compound typically contains two or more functional groups represented by the following formula:

Its R, R', R" and R''' are the linking groups and the average number of repetitions of x, y, z as their related groups. These repeating units may be randomly distributed. X and X' represent the functional group, usually The functional group X is different from the functional group X'. The selected X and X' functional groups, such as X', can cross-react with the material of the substrate 42 by forming covalent bonds, ionic bonds and/or van der Waals forces. .

Another functional group selected for X and X', such as X, can create a covalent bond with the material forming substrate 42. The X-based functionality can cross-react during the polymerization of the tie layer 50. Therefore, the functional group X is selected depending on the characteristics of the material forming the connection layer 50, and the functional group X is preferably reactive with the functional group forming the composition of the connection layer 50. For example, if the tie layer 50 is formed from an acrylic monomer, X may comprise an acrylic acid, a vinyl ether, and/or an alkoxy functional group, and/or a functional group copolymerizable with the acrylic group in the tie layer 50. Thus, the X functional group produces a cross-reaction under ultraviolet light actinic energy.

The functional group X' may also participate in the crosslinking and polymerization of the underlayer 45. In general, the X' functional group readily undergoes polymerization and cross-linking reactions with actinic energy that is cross-reactive with the X functional group. The X' functional group in this example readily crosslinks with the molecules in the underlayer 45 under exposure to thermal energy. Generally, the functional group X' which is liable to cross-react with the substrate 42 is selected via three mechanisms: (1) directly reacting with the material forming the substrate 42; (2) cross-linking with a bonding functional group in cross-linking reaction with the substrate 42 The molecules generate a reaction; and (3) polymerize and crosslink the underlayer 45 to form a molecular chain of sufficient length to connect the tie layer 50 to the substrate 42.

Referring to Figures 7 and 8, an exemplary polyfunctional compound which can be used to form the bottom layer 45 in the presence of the tie layer 50 is formed from a matrix material including beta-CEA supplied by UCB Chemical Company of Smyrna, Ga. Carboxyethyl acrylate. β-CEA is an aliphatic compound having the following structural formula:

The X' functional group 70 has a carboxyl functionality. The X functional group 72 has acrylic functionality. Functional groups 70 and 72 are coupled to opposite ends of compound backbone 74.

Referring to Figures 7 and 9, another polyfunctional compound which can be used to form the bottom layer 45 in the presence of the tie layer 50 is formed from a base material including those supplied by UCB Chemical Company, Smyrna, GA. An aromatic bisphenyl compound of the formula 3605 having the following formula:

The X' functional group 76 has an epoxy functional group. The X functional group 78 has acrylic functionality. Functional groups 76 and 78 are coupled to opposite ends of compound backbone 80.

Referring to Figures 7 and 10, another polyfunctional compound which can be used to form the bottom layer 45 in the presence of the tie layer 50 is formed from a base material including the Schenectady International Company of Schenectady, New York. 501 aromatic compound. The X' functional group 82 has a carboxyl functionality. The X functional group 84 has acrylic functionality. Functional groups 82 and 84 are coupled to opposite ends of compound backbone 86.

Depending on the method of synthesis, 501 has the configuration A or B shown below, or a similar configuration.

In configurations A and B, x and y are integers representing the number of repeating units. The repeating unit can be a random distribution.

Structures A and B can be made from the cresol epoxy phenolic shown below, which is a repeating unit that can range from x to y = n from 8 to 11. Thus, the molecular weights of constructs A and B range from about 2,000 to about 4,000 Daltons.

The high molecular weight of the constructs A and B increases the mechanical strength of the adhesive layer. With a universal carbon-carbon bond length of about 0.14 nanometers, the configurations A and B and the polymeric backbone can range from about 2 nanometers to about 4 nanometers when extended in a straight line.

Referring to Figures 7 and 11, in addition to cross-reacting with the tie layer 50, the functional group X can generate free radicals which facilitate polymerization of the composition of the tie layer 50 during curing. Thus, the functional group X will facilitate the polymerization of the tie layer 50 when exposed to actinic energy such as broadband ultraviolet light energy. An exemplary polyfunctional compound comprising these properties is a product supplied by Ciba Specialty Chemicals, Tarrytown, New York. Photoinitiator of 2959 having the following formula:

The X' functional group 90 has a carboxyl functionality. The X functional group 92 has an initiator type functionality. Specifically, the functional group X can undergo alpha-cleavage upon exposure to broadband ultraviolet light energy to produce a benzamidine-type radical. This radical facilitates the formation of a radical polymerization reaction of the composition of the tie layer 50. Functional groups 90 and 92 are coupled to opposite ends of compound backbone 94.

A number of compositions comprising the above polyfunctional reaction compounds have been formed to determine the bond strength of interfaces 66 and 68. The following are exemplary compositions including polyfunctional compounds:

Composition 1

β-CEA

DUV30J-16

Composition 1 contained about 100 grams of DUV 30J-16 and about 0.219 grams of beta-CEA. DUV30J-16 is a bottom anti-reflective coating (BARC) supplied with 93% solvent and 7% non-solvent reactive components from Brewer Scientific, Rolla, Missouri. DUV30J-16 contains a phenolic resin, and its crosslinker can react with a normal carboxylic acid functional group. It is believed that DUV 30J-16 will not form a covalent bond with tie layer 50.

In another composition, β-CEA is a crosslinker, a catalyst, and Replaced by 501. Both crosslinkers and catalysts were sold from Cytec Industries, Inc., West Patterson, New Jersey. The commercial name of the cross-linking agent is 303ULF. One component of 303ULF is hexamethoxymethyl melamine (HMMM). The methoxy functional group of HMMM can participate in many condensation reactions. The catalyst is a commercially available product having the following composition 4040:

Composition 2

DUV30J-16

501

303ULF

4040

Composition 2 contains about 100 grams of DUV 30J-16, 0.611 grams. 501, 0.175 grams 303ULF and 0.008g 4040.

DUV30J-16 is absent from another composition that can be used as a polyfunctional compound. The composition is as follows:

Composition 3

501

303ULF

4040

PM acetate

The composition contains about 77 grams 501, 22 grams 303ULF and 1 gram 4040. mixing 501 303ULF and 4040. followed by 501 303ULF and A mixture of 4040 introduced about 1900 grams of PM acetate. PM acetate is the product name of a solvent consisting of ethyl 2-(1-methoxy)acetate sold by Eastman Chemical Company of Kingsport, Tennessee.

Like composition 3, composition 4 contains about 85.2 grams. 501, 13.8 grams 303ULF and 1 gram A mixture of 4040. followed by 501 303ULF and A mixture of 4040 introduced about 1900 grams of PM acetate.

Like composition 3, composition 5 contains about 81 grams. 501, 18 grams 303ULF and 1 gram 4040. mixing 501 303ULF and 4040. followed by 501 303ULF and A mixture of 4040 introduced about 1900 grams of PM acetate.

The five compositions discussed above with respect to the compositions 1 to 5 of the underlayer 45 are respectively deposited on the substrate 42 by spin coating, wherein the substrate is rotated at a rotational speed of 500 to 4,000 revolutions per minute to form a non-flat but still have A substantially smooth bottom layer of uniform thickness. The composition was then exposed to thermo-optic energy at 180 ° C (Celsius) for about 2 minutes.

The adhesion strength of the interfaces 66 and 68 produced by the above five compositions and the matrix materials of the compositions 1 to 5 is completely different from the baseline of the DUV 30J-16 underlayer 45 which is formed from the base material and the connection layer 50 to form a covalent bond. Measure comparison data. For this purpose, the tie layer 50 formed from the base imprint material and the bottom layer 45 formed from the compositions 1 to 5 and the baseline composition are deposited and then cured between the two slides (not shown). Each slide (not shown) has a thickness of about 1 mm and a lateral dimension of 75 x 25 mm.

The slide (not shown) is cleaned prior to depositing the bottom layer 45 and the tie layer 50. Specifically, each slide (not shown) was placed in a Piranha solution (H ₂ SO ₄ :H ₂ O ₂ =2.5:1 by volume). The slides (not shown) were then washed with deionized water, sprayed with isopropanol, and dried under a stream of nitrogen. Thereafter, the slide (not shown) was baked at 120 ° C (Celsius) for 2 hours.

The bottom layer 45 was deposited on the two slides (not shown) by spin coating at 3000 rpm. The bottom layer 45 deposited on a glass slide (not shown) was heated on a 180 ° C hot plate for 2 hours. In other words, the compositions 1 to 5 and the baseline composition are respectively cured, i.e., polymerized and crosslinked, by exposure to heat. The tie layer is formed by the above-described droplet distribution method. Specifically, the substrate imprint material is placed on the bottom layer 45 of one of the two slides in a plurality of droplets. The substrate imprint material is sandwiched between the two bottom layers 45 by facing the underlying layers on two slides (not shown) and contacting the substrate imprint material. Typically, the long axis of one of the slides (not shown) extends vertically out of the long axis of the other slide (not shown). The base imprint material is cured by exposing the two slides (not shown) to an actinic energy, such as a broadband ultraviolet wavelength, by irradiating the medium pressure mercury UV lamp at an intensity of 20 mW/m 2 for 40 seconds. Polymerization and crosslinking.

In order to measure the adhesion strength, a measurement of adhesion between a mold and a photocurable resin in an imprint technique is used. Four-point bending jig (not shown) is described in Japanese Journal of Applied Physics, Vol. 41 (202), pages 4194 to 4197. . The maximum viscosity/load is used as the viscosity value. The horizontal distance between the top and bottom points is 60 mm. The load was applied at a rate of 0.5 mm per minute. Using this test, the peeling of the bottom layer 45 formed from the baseline composition at 6.1 pounds of applied force can be determined. A separation force of about 6.5 pounds is reached before the formation of the bottom layer 45 from the composition 1 begins to peel off. A separation force of about 9.1 pounds was reached before the formation of the bottom layer 45 from the composition 2 began. The bottom layer 45 formed from the composition 3, 4 or 5 fails (broken) one or two slides (not shown) before peeling occurs. It was found that the application of force up to 11 pounds did not cause it to peel off. As a result, it was found that the compositions 3, 4 and 5 provided extremely excellent operational characteristics of the underlayer 45 in the thin layer 60 having a poor thin region or all of the defects because it was effective in preventing peeling.

Composition 6 is a low solid composition similar to composition 5 which contains 0.81 g 501, 0.18 grams 303ULF, 0.01g 4040, and 1999 grams of PM acetate. In one example, composition 6 can be cast onto a wafer and spun to form a film. In the spinning method, a solvent is evaporated to form a solid film on the surface. A film of the desired thickness can be obtained on a substrate or wafer by adjusting the percentage of dissolved solids in the composition and the spin speed. After spin coating, the adhesive layer was cured by baking on a hot plate at 150 ° C for about 1 minute.

12A and 12B illustrate the measurement position 1200 of the thickness of the polymeric adhesive layer of the above composition 6 applied at 1000 rpm on an 8" wafer. The measurement was performed by a spectroscopic reflectometer equipped with an optical measuring system from Metrosol, Austin, Texas. The solid film thickness of the sample. In Figure 12A, 59 measurement positions are shown. The average thickness of the layer measured is 1.09 nm, the maximum measured thickness is 1.22 nm, the minimum measured thickness is 0.94 nm, and the standard deviation is 0.05 nm. In Figure 12B, 49 measurement positions are shown. The average thickness of the layer measured by VUV-7000 is 1.01 nm, the maximum measured thickness is 1.07 nm, and the minimum measured thickness is 0.95 nm. The standard deviation is 0.03 nm.

Fig. 13 is a scanning electron microscope (SEM) image of the polymerizable adhesive layer 1300 formed from the composition 6 between the yttrium oxide surface on the tantalum wafer 1302 and the acrylic embossed photoresist 1304. The thickness of the polymerizable adhesive layer 1300 is about 1 nm. Tests have shown that a 1 nm thick polymeric adhesive layer can achieve the same adhesive strength as a polymeric adhesive layer having a relatively thick (e.g., greater than about 6 nm) similar composition. That is, the polymeric adhesive layer 1300 does not cause adhesive failure when the tensile load is applied during the separation of the template.

Surprisingly, spin coating a polymeric adhesive layer composition comprising a polymeric component having an extended backbone length greater than about 2 nanometers (e.g., in the range of from about 2 to about 4 nanometers) has been shown to be formed to have a thickness of less than about 2 A polymerizable adhesive layer of nanometer (for example, about 1 nm). The polymeric components are believed to be aligned during spin coating such that the backbone of the polymeric component is "flat" (or nearly parallel) to the surface of the substrate rather than "standing" (or nearly perpendicular) to the surface of the substrate. It has been considered that the polymer component arranged on the surface of the substrate in this manner is generally formed on the surface of the substrate with a long dimension of the polymer component extending along the surface of the substrate to have a planar configuration and to form an ultra-thin layer on the substrate. This ultra-thin polymeric adhesive layer has been shown to have a stronger bond strength than a generally thicker adhesive layer and to reduce the overall thickness of the embossed stack used in nanoimprint lithography.

The above specific embodiments of the invention are merely exemplary. Many variations and modifications can be made to the above disclosure without departing from the scope of the invention. For example, the PM acetate solvent is mainly used to dissolve the other constituents of the compositions 3, 4 and 5. Therefore, many conventional photoresist solvents can be used in place of PM acetate, such as diethanol monoethyl acetate, methyl amyl ketone, and the like. In addition, the solids in the compositions 3, 4 and 5, ie 501 303ULF and 4040, the content may be between 0.1% and 70% by weight of the composition, and more preferably in the range of 0.5% to 10% by weight, and the remainder is composed of a solvent. Each solid component of the compositions 3, 4, and 5 contains 50% to 99% by weight 501, 1% to 50% by weight 303ULF, and 0% to 10% by weight 4040. Therefore, the scope of the invention should not be construed as being limited by the foregoing description, but rather the full scope of the appended claims and their equivalents.

10. . . system

36. . . Mold

38. . . dent

40. . . Projection

42. . . Substrate

44. . . surface

45. . . Bottom layer

46. . . Droplet

47. . . Wafer

50. . . Connection layer

52. . . Secondary segment

54. . . Secondary segment

56. . . Side

58. . . surface

60. . . Thin layer

62. . . First opposite side

64. . . Second opposite side

66. . . First interface

68. . . Second interface

70. . . Functional group

72. . . Functional group

74. . . Compound backbone

76. . . Functional group

78. . . Functional group

80. . . Compound backbone

82. . . Functional group

84. . . Functional group

86. . . Compound backbone

90. . . Functional group

92. . . Functional group

94. . . Compound backbone

136. . . Secondary segment

137. . . Secondary segment

146. . . Droplet

236. . . Secondary segment

237. . . Secondary segment

d. . . distance

T2. . . thickness

T1. . . thickness

Figure 1 is a simplified plan view of the prior art;

Figure 2 is a simplified elevational view of a stencil and embossing material placed on a substrate in accordance with the present invention;

Figure 3 is a simplified elevational view of the template and substrate of the imprinting material shown in Figure 2, which has been patterned and formed into a cured layer;

Figure 4 is a cross-sectional view of a template for forming a weak boundary layer between a cured imprint material and a stencil in contact with an imprint material;

Figure 5 is a detailed view showing the droplets of the imprint material shown in Figure 2, the droplets being separated to form a surfactant-rich region and a surfactant-deficient region;

Figure 6 is a detailed view showing the deposition of the layer of imprinted material by spin coating to show that the layer is separated to form a surfactant-rich region and a surfactant-deficient region;

Figure 7 is a cross-sectional view of a cured imprint material template deposited on a substrate comprising a bottom layer by contact with the method of Figure 5 or 6;

Figure 8 is a chemical structural formula that can be used to form a composition of a bottom layer;

Figure 9 is a chemical structural formula that can be used to form a composition of a bottom layer;

Figure 10 is a chemical structural formula that can be used to form a composition of a bottom layer;

Figure 11 is a chemical structural formula that can be used to form a composition of a bottom layer;

Figures 12A and 12B are measurement positions for measuring the thickness of the polymeric adhesive layer;

Figure 13 is a scanning electron micrograph image of a cross-section of a germanium wafer coated with a polymerizable adhesive layer.

36. . . Mold

38. . . dent

40. . . Projection

42. . . Substrate

44. . . surface

45. . . Bottom layer

46. . . Droplet

47. . . Wafer

d. . . distance

Claims (15)

An imprint lithography imprint stack comprising: a substrate; and a polymeric adhesive layer attached to the substrate, wherein the polymerizable adhesive layer has a thickness of less than about 2 nm; wherein the polymeric adhesive layer It is formed by a composition comprising: a polymer obtained by the following cresol epoxy novolac Wherein n represents the number of repeating units, and hexamethoxymethyl melamine. The embossed stack of claim 1, wherein the polymerizable adhesive layer has a thickness of about 1 nm. The embossed stack of claim 1, wherein the polymer made from cresol epoxy novolac has an extended backbone length of at least about 2 nanometers. An embossed stack according to claim 3, wherein the polymer obtained from cresol epoxy phenolic comprises a carboxylic acid functional group capable of bonding to the substrate and the other can be combined with an embossing photoresist Functional group. The embossed stack according to any one of claims 1 to 4, wherein the polymer obtained from cresol epoxy phenolic comprises the structure A shown below Here x and y represent the number, where x+y=n. The embossed stack according to any one of claims 1 to 4, wherein the polymer obtained from cresol epoxy phenolic comprises the structure A as defined in claim 5, or as follows Construction B Here x and y represent the number, where x+y=n. An embossed stack according to any one of claims 1 to 4, wherein The polymeric adhesive layer is capable of bonding the imprinted photoresist during curing of an imprint photoresist on the imprint stack. A method of forming an adhesive layer on an imprint lithography substrate, the method comprising: spin coating a polymerizable composition onto an imprint lithography substrate; and curing the polymerizable composition to form an adhesion to The polymerizable adhesive layer of the embossed lithography substrate, wherein the polymerizable adhesive layer has a thickness of less than about 2 nm; wherein the polymerizable adhesive layer is formed by a composition comprising the following: Methylphenol epoxy phenolic resin Wherein n represents the number of repeating units, and hexamethoxymethyl melamine. The method of claim 8, wherein the polymerizable adhesive layer has a thickness of about 1 nm. The method of claim 8, wherein the polymer made from cresol epoxy novolac has an extended backbone length of at least about 2 nanometers. The method of claim 8, wherein the polymer composition comprises a polymerizable component, and the polymerizable component comprises a bond capable of bonding to the substrate. A carboxylic acid functional group and another functional group capable of binding to an embossed photoresist. The method of any one of claims 8 to 11, wherein the polymer obtained from cresol epoxy novolac comprises the structure A shown below. Here x and y represent values, where x+y=n. The method of any one of claims 8 to 11, wherein the polymer obtained from the cresol epoxy novolac comprises the structure A as defined in claim 12 or the structure B as shown below. Here x and y represent values, where x+y=n. The method of any one of claims 8 to 11, further comprising applying an embossed photoresist to the polymerizable adhesive layer and curing the embossed photoresist, wherein the embossed photoresist is cured The bonding of the embossed photoresist to the polymeric adhesive layer is included. An embossing lithography method comprising: spin coating a polymerizable composition onto an embossed lithography substrate, wherein the polymerizable composition comprises a polymeric component, wherein the polymeric components have an extended backbone length of at least About 2 nm; the main chain of the polymeric components are substantially aligned into a planar configuration on the surface of the imprint lithography substrate; and the polymerizable composition is cured to form an adhesion to the imprint lithography substrate a polymerizable adhesive layer, wherein the polymerizable adhesive layer has a thickness of less than about 2 nm; wherein the polymerizable adhesive layer is formed by a composition comprising: a cresol epoxy phenolic resin as shown below Obtained polymer Wherein n represents the number of repeating units, and hexamethoxymethyl melamine.