HK1089243A - Method of controlling the differential dissolution rate of photoresist compositions - Google Patents

Description

Method for controlling dissolution rate difference of photoresist composition

Cross Reference to Related Applications

This application claims priority to U.S. provisional application No.60/449785, filed 24/2/2003, according to the provisions of 35u.s.c. 119.

Technical Field

The present invention relates generally to methods for controlling the dissolution rate of polymers used to form photoresist compositions, and more particularly to polymers having cycloalkyl repeat units that control the solvent rate of such polymers in photoresist compositions, and compositions thereof.

Background

Photoresists are photosensitive films used for transfer of an image formed therein to an underlying layer or substrate. A photoresist layer is formed on a substrate, typically a layer of material to which an image is to be transferred. The photoresist layer is then exposed to activating radiation through a photomask having areas that are opaque to the radiation and other areas that are transparent to the radiation. The light-induced chemical changes cause the areas exposed to the activating radiation to be able to develop a stereoscopic image therein.

The photoresist may be positively or negatively colored. In general, negative tone photoresists undergo a crosslinking reaction in those portions of the photoresist layer that are exposed to activating radiation. As a result, the exposed portions are less soluble in the solution used to develop the stereoscopic image than the unexposed portions. In contrast, for a positive tone photoresist, the exposed portions of the photoresist layer are more soluble in a developer solution than the portions not exposed to the radiation.

As microelectronic devices, such as integrated circuits, implement their functionality using smaller and smaller device structures, there is an increasing demand for photoresist compositions that are capable of dissolving these device structures. While the dissolution capacity of a particular photoresist composition for a particular device structure is a function of a number of factors, one of these factors is the control of the difference in dissolution rates of the exposed and unexposed portions of the photoresist. While this factor has been previously studied, the starting point for such research has often been the development of additives that can be used to increase the difference in dissolution rate of these exposed and unexposed portions in a developer solution. However, these additives may adversely affect other properties of the photoresist composition, for example, by increasing the optical density of the composition at the operating wavelength of the activating radiation, and further, perhaps more importantly, by merely increasing the difference in the dissolution rates of the exposed and unexposed portions, the difference in dissolution rates cannot always be controlled.

Therefore, there is a need to provide photoresist compositions that can be controlled for poor dissolution rates. I.e., the difference in the dissolution rate of the exposed and unexposed portions of the photoresist is controllable. It is also desirable that such photoresist compositions include polymeric materials that are capable of controlling such dissolution rate differentials and that do not require additives. It is also desirable to provide polymeric materials for use as the base resin of such photoresist compositions and methods of forming such desired polymers.

Drawings

FIG. 1 is a schematic representation of the exo and endo isomers of 5-methyl-2-norbornene;

FIG. 2 is a table showing the ratio of exo/endo isomers of several α, α -bis (trifluoromethyl) bicyclo [2.2.1] hept-5-ene-2-ethanol (HFANB) monomers used in polymerization according to an embodiment of the invention;

FIG. 3 is a three-dimensional histogram of dissolution rate versus molecular weight and exo mole percent for an exemplary embodiment of the present invention.

FIG. 4 shows a scanning electron micrograph of a polymer mixture having about 50 wt% homopolymer having a selected exo mole percent and a relatively high molecular weight; and

FIG. 5 shows a scanning electron micrograph of a polymer mixture having about 50 wt% homopolymer having a selected exo mole percent and a relatively low molecular weight.

Detailed Description

The preparation of norbornene derivatives (hereinafter referred to as monomers for forming polycycloolefin resins) generally results in a mixture of exo isomers and endo isomers (see FIG. 1). Generally, purification of the reaction mixture resulting from the synthesis of monomers useful in embodiments of the present invention involves fractional distillation methods. According to the observation: the different fractions collected from this distillation had different ratios of exo and endo isomers as described above (see FIG. 2). To determine the effect that this difference in isomer ratio may have on the properties of polymers formed with different fractions, homopolymers were formed with each of these fractions.

It has been found that advantageously: the resulting polycycloolefin resin had an unexpected change in its dissolution rate. It was not surprising that the change in the dissolution rate of these resins as a function of molecular weight (expressed as Mn or Mw) was observed, which was generally observed, but that the change was mainly observed as a function of the ratio of exo-and endo-isomers in the monomer feed (see fig. 3).

For example, it has been found that a first resin having a Mn of 3560 polymerized from a monomer having a mole percent (mol%) of exo-isomer of 48 has a Dissolution Rate (DR) of 3920 angstroms/second (sec), while a second similar resin having a molecular weight of about twice that of the same starting monomer (Mn of 7520) has a DR of 3850 sec. Therefore, it is surprising that the resins with very different molecular weights have almost the same DR (see examples 21 and 22 in table 1). Similarly, a third resin with Mn 3270 polymerized with monomers having 22 mol% exo isomer had a DR of 6627 sec, while a fourth similar resin with a molecular weight of about four times that polymerized with the same starting monomers (Mn 13700) had almost the same DR (DR 6543 sec, see examples 16 and 20 in Table 1).

For each of the above examples, the resin was a homopolymer of α, α -bis (trifluoromethyl) bicyclo [2.2.1] hept-5-ene-2-ol (HFANB) formed in essentially the same manner. Thus, for each pair (21 and 22, 16 and 20) only the concentration of chain transfer agent used for the polymerization is varied to provide polymers having different molecular weights.

Comparing the DR of the first pair of resins (21 and 22) with the DR of the second pair of resins (16 and 20), it is clear that the DR of the second pair of resins is about twice that of the first pair of resins. Since both pairs of resins are HFANB homopolymers, differing only in the mole percent of exo isomer in the starting monomers, the applicants believe that the difference in dissolution rate is a function of the difference in the mole percent of exo isomer. Thus, if the exo isomer concentration in the raw material monomers decreases, for example, from 48 mol% in the first pair of resins to 22 mol% in the second pair of resins, the dissolution rate increases.

Referring to FIG. 3, there is a three-dimensional histogram showing DR values versus exo mole% and molecular weight (Mn) for each of examples 12-23 (see Table 1) showing this relationship. It should be noted, however, that the exo mol% is not linearly related to DR, and that a threshold occurs at exo mol% values of about 25% to about 40%. I.e., the first range of exo isomer content appears to have a more constant first DR (about 6000-7200. cndot./sec), while the second range of exo isomer content appears to have a more constant second DR (about 3500-4000. cndot./sec), which is very different from the first DR.

It should be noted that, although the applicant has in advance no specific theory able to explain these surprising effects observed (see the preceding and fig. 3), it has been known that: the rate of dissolution of the polymer is a function of its solubility in the developer solution and also of the particular side chain group substituents present on the repeating units forming the polymer backbone. In addition, if these repeat units are derived from polycyclic olefins, the solubility of the polymer is also a function of whether the pendant groups are substituted in an external or internal position, since it is known that if the pendant groups are substituted externally, they are more reactive than if the same groups are substituted internally. Thus, while it has been observed previously that polymer dissolution rate is often a function of molecular weight, if other factors are the same, applicants believe that by varying whether the reactive side chain groups are substituted at external positions on the polymer repeat unit, the polymer dissolution rate can be effectively controlled to increase or decrease as is generally desirable.

Despite the above facts, it is additionally known that: the dissolution rate properties of the binder resin are important in developing high performance photoresist formulations and composites. For example, Ito et al reported in Proceedings of SPIE, 2003, 5039, 70: when studying HFANB homopolymers prepared with Ni and Pd catalysts using the quartz crystal microbalance method, it was shown that there is no direct relationship between the "dissolution rate [ in 0.26N TMAH ] and Mn or Mw". Ito also investigated the dissolution rate performance of the same polymer with a more dilute 0.21NTMAH solution, but found that the dissolution rate performance is complex, as it appears to depend on the molecular weight polydispersity of the polymer. The dissolution rate performance of HFANB homopolymer in 0.19N TMAH solution in the case of homopolymer prepared with Pd-only catalyst was reported by Hoskins et al in Proceedings of SPIE, 2003, 5039, 600. Hoskins reported the dissolution rate after optical interferometry: HFANB homopolymer "dissolution rate was found to have an irregular dependence on molecular weight". Hoskins thus found: the dissolution rate of low molecular weight HFANB homopolymers (Mw < 10000) decreases with increasing molecular weight, while the dissolution rate of homopolymers of 10000 < Mw < 100000 increases with increasing molecular weight. It should be noted, however, that the molecular weight polydispersity of the Hoskins samples is broad, ranging from 1.91 to 9.21, which may complicate the interpretation of the dissolution rate performance.

Thus, to simplify the study of the dissolution rate performance, the applicants decided to prepare HFANB homopolymers using only Pd catalyst and process conditions that resulted in a narrower molecular weight polydispersity (i.e., 1.50 to 2.50). To further avoid complexity, applicants measured the dissolution rate performance of this homopolymer using only a standard 0.26N TMAH solution and quartz crystal microbalance method.

Because applicants' understanding of dissolution rate performance has improved, applicants believe that binder resins for positive and negative photoresist compositions can be produced, and based on this understanding, the difference between the dissolution rates of exposed and unexposed portions of the photoresist layer (dissolution rate difference) can be controlled. Additionally, the present application recognizes and has demonstrated: this understanding can lead to better imaging over a wider range of polymer parameters, for example over a wide range of molecular weight changes. It should also be noted that the choice of HFANB monomers for the homopolymers studied is also influenced by the use of these monomers in the large number of reported photoresist binder resin formulations, and therefore the resulting understanding is more readily applicable.

In addition, homopolymers used for dissolution rate studies were prepared using olefin and non-olefin Chain Transfer Agents (CTA). The homopolymer thus formed was analyzed to conclude the following: the physical properties of the polymer, such as Mw, Mn, OD (optical density), etc., can be varied by the choice of CTA used in the polymerization process.

While homopolymers formed by vinyl addition polymerization have been observed previously, it has been demonstrated that polymers formed with more than one monomer exhibit similar dissolution rate effects and should also enhance imaging performance. Thus, described below are monomers useful in practicing embodiments of the present invention, and polymers formed from such monomers include at least one monomer having the desired exo-isomer mol%.

Embodiments of the present invention include repeat units from norbornene-type monomers having acid-labile protecting side chain groups. Such monomers are represented by the following formula a:

formula A

Wherein m and Z are as defined above, R¹、R²、R³Or R⁴Is independently an acid labile protecting side chain group that can be cleaved by an acid such as generated by a photoacid generator. Any acid labile group known in the literature and in the art may be used in the present invention, such as those groups listed herein in connection with formula a.

The remaining one or more R¹、R²、R³Or R⁴May independently be hydrogen, or a hydrocarbyl group having 1 to about 20 carbon atoms, or a halogen selected from F, Cl or Br, or a hydrocarbyl group having 1 to about 20 carbon atoms and any hydrogen atom substituted with O, S, N, Si, or the like, or a fluorinated hydrocarbyl group having 1 to about 20 carbon atoms and wherein each carbon atom is independently substituted with 0, 1, 2, or 3 fluorine atoms.

Turning to the acid labile protecting groups, in some embodiments these groups are fluorinated carbinol moieties having from 1 to about 20 carbon atoms wherein each carbon atom is independently substituted with 0, 1, 2, or 3 fluorine atoms and the oxygen atom is protected by an acid labile group that can be cleaved by an acid generated by a photoacid generator. Wherein exemplary fluorinated groups include- (CR)₂)_nOR′、-(O-(CH₂)_n)_n-C(CF₃)₂-OR′、-(CH₂O)_n-C(CF₃)₂-OR′、-((CH₂)_nO)_n-CH₂-C(OR′)(CF₃)₂Wherein each n is independently selected from an integer of 0 to about 5, and each R is independently hydrogen or halogen (i.e., F, Cl, Br, I), wherein R' is an acid labile group. R' includes but is not limited to-CH₂OCH₃(dimethyl ether), -CH₂OCH₂CH₃(first)Ethyl ether), -C (CH)₃)₃、-Si(CH₃)₃、-CH₂C (O) O (t-Bu), 2-methylnorbornyl, 2-methylisobornyl, 2-methyl-2-adamantyl, tetrahydrofuranyl, tetrahydropyranyl, 3-oxocyclohexanonyl, mevalonic lactone, dicyclopropylmethyl (Dcpm) OR dimethylcyclopropylmethyl (Dmcp) group, OR R' is-C (O) OR "wherein R" is-C (CH-Bu), 2-methylnorbornyl, 2-methylisobornyl, 2-methyl-2-adamantyl, tetrahydrofuranyl, tetrahydropyranyl, 3-oxocyclohexanonyl, mevalonic lactone, dicyclopropylmethyl (Dcp₃)₃、-Si(CH₃)₃2-methylnorbornyl, 2-methylisobornyl, 2-methyl-2-adamantyl, tetrahydrofuranyl, tetrahydropyranyl, 3-oxocyclohexanonyl, a lactone group of mevalonate, a Dcpm or Dmcp group or combinations thereof.

In some embodiments of the invention, formula a may also be represented by formula a1 below:

formula A1

Wherein n and R' are as defined above, and more specifically, monomers comprising an acid-labile pendant protecting group of formula A1 include:

the norbornene-type monomer of formula A may also be represented by the following formula A2:

formula A2

Wherein n' is an integer of 0 to 5, R^a、R^bAnd R^cIndependently represent C₁To about C₂₀A straight or branched hydrocarbon group of (2), or R^aAnd R^bAnd the common carbon atom to which they are attached together represent a saturated cyclic group containing 4 to 12 carbon atoms. Exemplary norbornene-type monomers according to formula a2 include:

or

Wherein tBu is tert-butyl.

Some embodiments of the invention include repeat units from norbornene-type monomers having pendant groups capable of crosslinking. These monomers are represented by the following formula B:

formula B

Wherein m and Z are as defined above, and each R⁵、R⁶、R⁷And R⁸Are each independently H, halogen, straight, branched or cyclic C₁-C₃₀Alkyl, alkyl alcohol, aryl, aralkyl, alkaryl, alkenyl, or alkynyl; with the proviso that at least one R⁵、R⁶、R⁷And R⁸Is a functional group capable of crosslinking. Suitable functional groups capable of crosslinking include, but are not limited to, hydroxyalkyl ethers represented by formula I:

-A-O-[-(CR^** ₂)_q-O-]_p-(CR^** ₂)_q-OH formula I

Wherein A is selected from C₁-C₆A straight, branched or cyclic alkylene linking group, each R^**Are each independently selected from H, methyl, and ethyl, q is independently an integer from 1 to 5, and in some cases from 2 to 5, and p is an integer from 0 to 3.

Other suitable functional groups capable of crosslinking are represented by formulas II, III, IV, and V:

-R^***-Q formula II

-(CH₂)_nC(O)OR^#Formula III

-(CH₂)_t-C(CF₃)₂-O-(CH₂)_t-CO-(OR^##) Formula IV

Wherein, for formula II, R^***Is optionally partially or fully halogenated, linear, branched or cyclic C₁-C₃₀An alkylene, arylene, aralkylene, alkarylene, alkenylene, or alkynylene linking group, and Q is a functional group selected from the group consisting of hydroxyl, carboxylic acid, amine, thiol, isocyanate, and epoxy. For formula III, n is as defined above and R^#Represents an acid labile group that can be cleaved by a photoacid generator. Finally, for formula IV, each t is independently an integer from 1 to 6, R^##Is C₁-C₈Straight or branched alkyl moieties, in some cases tertiary butyl.

Additionally, some embodiments of the invention also include repeat units from norbornene-type monomers having side chain groups that are not acid labile protecting groups and crosslinkable groups. These monomers are represented by the following formula C:

formula C

Wherein m and Z are as defined above, and the substituents R⁹、R¹⁰、R¹¹And R¹²Each independently selected from neutral substituents selected from halogen (i.e., F, Cl or Br), - (CH)₂)_n-C(O)OR²¹、-(CH₂)_n-(CM₂)_n-OR¹⁸、-(CM₂)_n-OC(O)R¹⁷、-(CH₂)_n-OC(O)OR¹⁷、-(CH₂)_n-C(O)R¹⁸、-(CH₂)_nC(R¹⁹)₂CH(R¹⁹)(C(O)OR²⁰)、-(CH₂)_n-NH-(SO₂)-CF₃、-(CH₂)_nC(R¹⁹)₂CH(C(O)OR²⁰)₂、-C(O)O-(CH₂)_n-OR¹⁸And- (CH)₂)_n-O-(CH₂)_n-OR¹⁸、-(CH₂)_n-(O-(CH₂)_n)_n-C(CF₃)₂OR²¹Wherein each n is independently an integer from 0 to 5, M can be hydrogen or halogen (i.e., F, Cl or Br), R¹⁹May independently be hydrogen, halogen, straight or branched C₁-C₁₀Alkyl or cycloalkyl or straight or branched C₁-C₁₀Halogenated alkyl or halogenated cycloalkyl radicals R¹⁸May independently be hydrogen, straight or branched C₁-C₁₀Alkyl or cycloalkyl or straight or branched C₁-C₁₀Halogenated alkyl or halogenated cycloalkyl radicals R²⁰Is not easily cleaved by the photoacid generator, and may independently be a straight or branched chain C₁-C₁₀Alkyl or cycloalkyl or straight or branched C₁-C₁₀Halogenated alkyl or halogenated cycloalkyl radicals R¹⁷Is not easily cleaved by the photoacid generator, and may independently be a straight or branched chain C₁-C₁₀Alkyl or halogenated alkyl, monocyclic or polycyclic C₄-C₂₀A cycloaliphatic or halogenated cycloalkyl moiety, a cyclic ether, a cyclic ketone or a cyclic ester (lactone), wherein the cyclic ether, cyclic ketone or cyclic ester may or may not be halogenated, R²¹Is defined as R¹⁷And (4) hydrogenation. Exemplary alicyclic moieties include, but are not limited to, unsubstituted cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, adamantyl, and 1-norbornyl moieties. In addition, R⁹、R¹⁰、R¹¹And R¹²May each be independently selected from neutral substituents represented by formula I:

-A-O-[-(CR^** ₂)_q-O-]_p-(CR^**)_q-OH formula I

Wherein A and q are as defined above and R^**Selected from halogens.

Thus, it can be appreciated that the polymers of embodiments of the present invention include repeat units from any of the polycycloolefin monomers of formulas A, B and C. These monomers can be produced in a variety of ways, and the methods and catalyst systems for polymerizing these monomers are described in detail in US 5468819, US5569730, US 6136499, US 6232417 and US 6455650, which disclosures are incorporated herein as part of the present application. Exemplary methods of forming polycyclic olefin monomers include Diels-Alder condensation reactions using cyclopentadiene and a suitable dienophile, or the reaction of a suitably substituted polycyclic olefin having a desired mol% exo-isomer with reagents suitable for forming the final desired monomer.

As mentioned above, it has been found that monomers having the desired mol% exo isomer have a good effect on the dissolution rate of the polymer prepared therefrom. In some embodiments, the desired exo mol% is greater than the desired exo mol% for the polycyclic olefin monomer based on the thermodynamic equilibrium of the monomer isomers obtained by the Diels-Alder reaction. In other embodiments, the desired exo mol% is less than the exo mol% desired for the polycyclic olefin monomer based on the thermodynamic equilibrium of the monomer isomers obtained by the Diels-Alder reaction. This desired exo-isomer mol% can be obtained by the following method: for example, in the purification by fractional distillation, an appropriate portion of the monomers is selected. However, the method of obtaining such monomers is not limited to fractional distillation or any other purification method. Rather, the desired exo mol% suitable for use in embodiments of the present invention may be obtained by any suitable method and the monomers obtained by such suitable method are within the scope and spirit of the present invention.

It is to be understood that the polymers in embodiments of the present invention include at least one polycycloolefin repeat unit from a polycycloolefin monomer having the desired exo mole%. But these polymers also include repeat units from a variety of other monomers. For example, the polymers can include repeat units from maleic anhydride monomers, acrylate monomers, trifluoromethyl acrylate monomers, and the like, as well as mixtures of these different monomers. In addition, the polymers of the present invention may be formed by any suitable polymerization method, including vinyl addition, ring opening exchange polymerization (ROMP), and free radical processes, provided that such polymerization methods do not substantially alter the exo mole% of the polycyclic olefin monomer used. It should also be understood that the polymers of the present invention are not limited to having only a single repeat unit having mol% of the desired exo isomer. Therefore, polymers comprising two or more such repeat units are also within the scope and spirit of the present invention.

Good polymers produced by the present invention include addition-polymerized polycyclic repeat units attached by 2, 3-chains. These polymers comprise at least one monomer covered by the definition of formula C above and optionally one or more monomers covered by formulae A and/or B above and any other type of monomer described above. At least one of these monomers has the desired exo mol% to provide the desired dissolution rate or imaging properties to the resulting polymer. Advantageously, the desired exo mol% of at least one monomer can be obtained, for example, by selecting a suitable cut or cut point when fractionating the monomers. However, it is also possible to prepare the monomers by other methods which give the desired exo mol%, for example, in such a manner that the desired exo mol% is obtained directly.

It will of course be appreciated that: the dissolution rate and/or imaging properties obtained using a polymer having the desired exo mol% repeating unit also depend on the relative amounts of these repeating units added to the polymer. Thus, if a lower concentration of repeat units having mol% of the desired exo isomer is incorporated into the polymer, such a low concentration of repeat units has little or no effect on the dissolution rate or imaging properties of the polymer. However, if the concentration of the repeating unit having mol% of the desired exo isomer is high, a great influence on the dissolution rate or the image forming property of the resulting polymer can be observed. For example, see table 2 below: for the polymers of examples 24, 25 and 26 (about 87% HFANB), the dissolution rates of the polymers were substantially the same as observed for the HFANB homopolymers of examples 1-23. However, if the amount of HFANB is reduced, for example in the case of HFANB homopolymers and other materials discussed below, such as P (TBTFMA-VENBHFA) copolymers, the effect observed is also reduced.

Embodiments of the invention may also include polymers formed with more than one polycycloolefin monomer having reactive side chain groups ("reactive" herein means protecting acid labile side chain groups or side chain groups included in the dissolved polymer). Thus, there may be a different mol% of the desired exo isomer for each of these monomers. Although combining these different monomers in a polymer may require some experimentation to determine the appropriate mole% exo isomer for each monomer and the relative concentration of each monomer within the polymer, applicants believe that these experiments are simple and well within the capabilities of those of ordinary skill in the art.

It should now be appreciated that: embodiments of the present invention include polymers formed by vinyl addition polymerization and cyclic olefin monomers used to form these polymers, wherein at least one of these cyclic olefin monomers has the desired exo mol%. It should additionally be understood that: the polymer of some embodiments of the present invention includes at least one monomer selected from each of formulas A, B and C. These and other polymers of the present invention are useful in forming photoresist compositions having desirable dissolution rates and imaging properties. Some embodiments of the present invention include positive-tone (positive-working) polymers and photoresist compositions prepared therefrom. Other embodiments include negative-tone (negative-tone) polymers and photoresist compositions prepared therefrom. It is understood that the particular monomer selected to have the desired exo mol% includes a pendant group suitable for the desired photoresist composition type (positive or negative). It should also be clear that if some embodiments of the invention include exo isomer mol% enhanced monomers and resulting repeat units, other embodiments of the invention include endo isomer mol% enhanced monomers and resulting repeat units. It should also be noted that the side chain groups and resulting repeat units of the monomers of the present invention may or may not be protected by acid labile groups. Finally, embodiments of the invention include the selection of monomers having the desired exo mol% in any combination with various additives used to formulate photoresist compositions. For example, these additives may include photoacid generators, photoinitiators, dissolution rate modifiers, and the like, all of which may be monomeric, oligomeric, or polymeric in nature.

Various aspects of the invention will be more clearly understood from the following illustrative examples and illustrative polymeric structures of the invention. These examples are for illustrative purposes only and are not to be construed as limiting the scope and spirit of the present invention. Unless otherwise indicated, the molecular weights of the polymers prepared as reported in the following examples were determined by GPC in THF using polystyrene standards.

Synthesis example 1

Adding alpha, alpha-bis (trifluoromethyl) bicyclo [2.2.1] into a glass pressure reactor]Hept-5-ene-2-ethanol ((HFANB)80.0g, 0.292mol, endo/exo ratio 44/56), N-dimethylanilinium tetrakis (pentafluorophenyl) borate ((DANBABA) 0.0468g, 0.0584mMol) and toluene in an amount sufficient to achieve a total volume of 200 mL. The mixture was purged with hydrogen for 30min and then charged with hydrogen (90 psig). The reaction mixture was heated to 80 ℃. After the pressure was released, the palladium catalyst, palladium bis (diisopropylphenylphosphine) diacetate (0.0071g, 0.012mMol) was added. The reactor was quickly repressurized with hydrogen (90psig) and allowed to react for 18 h. The reaction mixture was cooled and passed through 0.22 micron Teflon^_Filtering by a filter to remove black palladium metal. The filtrate obtained was added to heptane, and a white powdery polymer was precipitated. The powder was collected by filtration and then dried in a vacuum oven at 90 ℃. The yield was 52.5g (66%). Mw 11300; mn 5440.

Synthesis example 2

HFANB (19.2g, 0.701mol, in/out ratio 70/30), DANFABA (0.0112g, 0.0140mMol) and toluene sufficient to achieve a total volume of 47mL were charged to the glass pressure reactor. The reactor was charged with 17psig of ethylene and heated to 80 ℃. After the pressure was released, the palladium catalyst-palladium bis (diisopropylphenylphosphine) diacetate (3mL of a 0.93mMol solution in dichloromethane) was added. The reactor was quickly repressurized with ethylene (17psig) and allowed to react for 20 h. The reaction mixture was cooled and excess hexane was added to precipitate the polymer. The polymer was collected by filtration and then dried in a vacuum oven at 80 ℃. The yield was 9.5g (50%).

The polymer was then dissolved in 48mL of toluene. To this mixture was added 24mL of glacial acetic acid, 12mL of hydrogen peroxide (30%) and 12mL of water. The mixture was heated to 80 ℃ and warmed for 3 h. The organic layer was separated and washed four times with water. The organic layer was concentrated by rotary evaporation and then poured into heptane to precipitate the polymer. The polymer was collected by filtration and then dried in a vacuum oven at 80 ℃. The yield was 8.8 g. The polymer was redissolved in methanol and precipitated by addition of water. Mw 6400; mn 3630.

Synthesis example 3

Synthesis example 2 was repeated except that ethylene at a pressure of 5psig was used. The yield was 11.4g (59%). The polymer was treated with glacial acetic acid and hydrogen peroxide as in synthesis example 2. The yield was 10.5 g. Mw 12900; mn 5930.

Synthesis examples 4, 5 and 6

Synthesis examples 4, 5 and 6 were conducted in the same manner as in Synthesis example 3 except that ethylene was used in different amounts to obtain different molecular weights. The yields are given in table 1 below. The polymer was treated with glacial acetic acid and hydrogen peroxide as in synthesis example 3. The molecular weights of the polymers are given in table 1 below.

Synthesis example 7

HFANB (19.2g, 0.701mol, in/out ratio 70/30), DANFABA (0.0112g, 0.0140mMol) and toluene sufficient to achieve a total volume of 47mL were charged to the glass pressure reactor. The mixture was charged with hydrogen (90 psig). Will reactThe mixture was heated to 80 ℃. After the pressure was released, the palladium catalyst-palladium bis (diisopropylphenylphosphine) diacetate (3mL of a 0.93mMol solution in dichloromethane) was added. The reactor was quickly repressurized with hydrogen (90psig) and allowed to react for 18 h. The reaction mixture was cooled and passed through 0.22 micron Teflon^_And (5) filtering by using a filter. The filtrate obtained was added to heptane, and a white powdery polymer was precipitated. The powder was collected by filtration and then dried in a vacuum oven at 80 ℃. The yield was 11.6g (61%). Mw 17860; mn 7270.

Synthesis example 8

Synthesis example 7 was repeated except that hydrogen was purged through the reaction mixture for 15min before pressurizing with 90psig hydrogen. The yield was 9.95g (52%). Mw 7900; mn is 4150.

Synthesis example 9

Synthesis example 1 was repeated except that the monomer had an endo/exo ratio of 85/15. The polymer was isolated by precipitation in hexane. The yield was 65.1g (80%). Mw 8870; mn 4880.

Synthesis example 10

Synthesis example 9 was repeated except that the monomer internal/external form ratio was 85/15 and the hydrogen pressure was 50 psig. The polymer was isolated by precipitation in hexane. The yield was 60.6g (76%). Mw 13600; mn is 5700.

Synthesis example 11

Synthesis example 9 was repeated except that the monomer external/internal type ratio was 85/15 and the hydrogen pressure was 50 psig. The polymer was isolated by precipitation in hexane. The yield was 61.9g (77%). Mw 11600; mn is 5820.

Synthesis example 12

HFANB (40.0g, 0.146mol, in/out ratio 90/10), DANFABA (0.0351g, 0.0438mMol), triethylsilane (2.31mL, 14.4mMol), ethanol (0.940mL, 16.2mMol), and toluene (68mL) were added to the flask. The flask was covered with a septum and the mixture was purged with nitrogen for 15 min. The mixture was then heated to 80 ℃ and the catalyst [ bis (diisopropylphenylphosphine) (acrylonitrile) palladium acetate ] [ tetrakis (pentafluorophenyl) borate ] (0.017g, 0.0146mMol) dissolved in a minimum amount of 1, 2-dichloroethane was added. The mixture was cooled and reacted for 18 h. The reaction mixture was cooled and added to heptane to precipitate a white powder of polymer. The polymer was collected by filtration, washed with heptane and dried in a vacuum oven at 100 ℃. The yield was 30.7g (77%). The polymer was redissolved in toluene. It was then reprecipitated in heptane, filtered and dried in a vacuum oven at 100 ℃. Mw 4670; mn 3120.

Synthesis example 13

Synthesis example 12 was repeated except that 0.28mL (0.177mol) of triethylsilane was used. The yields and molecular weights are reported in table 1 below.

Synthesis example 14

Synthesis example 12 was repeated, except that 1.1mL (0.0069mol) of triethylsilane was used. The yields and molecular weights are reported in table 1 below.

Synthesis example 15

Synthesis example 12 was repeated except that 0.55mL (0.0034mol) of triethylsilane was used. The yields and molecular weights are reported in table 1 below.

Synthesis example 16

HFANB (100g, 0.365mol, with an endo/exo ratio of 78/22), DANFABA (0.088g, 0.110mMol), triethylsilane (5.8mL, 36mMol), ethanol (2.3mL, 40mMol) and toluene (171mL) were added to the flask. The flask was sealed with a septum and heated to 80 deg.C before the catalyst [ bis (diisopropylphenylphosphine) (acrylonitrile) palladium acetate ] [ tetrakis (pentafluorophenyl) borate ] (1.0mL of a 0.0025M solution in dichloromethane) was added. The mixture was reacted for 18 hours. The reaction mixture was cooled and a small amount of acetone was added to reduce the solution viscosity. The reaction mixture was added to hexane in an excess of 10 times to precipitate a polymer as a white powder. The powder was collected by filtration and dried in a vacuum oven at 90 ℃. The yield was 30.1g (73%). Mw 5350; mn 3270.

Synthesis example 17

Synthesis example 16 was repeated except that 3.1mL (19mMol) of triethylsilane was used. The yields and molecular weights are reported in table 1 below.

Synthesis example 18

Synthesis example 16 was repeated except that 1.8mL (11mMol) of triethylsilane was used. The yields and molecular weights are reported in table 1 below.

Synthetic example 19

Synthesis example 16 was repeated except that 1.2mL (7.5mMol) triethylsilane was used. The yields and molecular weights are reported in table 1 below.

Synthesis example 20

Synthesis example 16 was repeated except that 0.89mL (5.6mMol) triethylsilane was used. The yields and molecular weights are reported in table 1 below.

Synthesis example 21

To a flask was added HFANB (41.1g, 0.150mol, in an endo/exo ratio of 58/42), DANBABA (1.0mL of a 0.0075M solution in dichloromethane), triethylsilane (1.73g, 0.0148mol), ethanol (0.77g, 0.017mol), and toluene in an amount sufficient to achieve a total volume of 100 mL. The reaction mixture was heated to 80 ℃ and then the palladium catalyst, palladium bis (diisopropylphenylphosphine) diacetate (1mL of a 0.0025M solution in dichloromethane) was added to the monomer solution. After 18h, the reaction mixture was cooled and then hexane was added to precipitate a white powder of polymer. The powder was collected by filtration and dried in a vacuum oven at 90 ℃. The yield was 30.2g (73%). Mw 5770; mn is 3560.

Synthesis example 22

Synthesis example 21 was repeated except that 0.54mL (4.6mMol) triethylsilane was used. The yields and molecular weights are reported in table 1 below.

Synthesis example 23

Synthesis example 21 was repeated except that 0.27mL (2.3mMol) triethylsilane was used. The yields and molecular weights are reported in table 1 below.

Synthesis example 24

To a flask was added HFANB (51.0g, 0.186mol, endo/exo ratio 90/10), 5-norbornene-2-hydroxyethyl ether ((HEENB)2.36g, 0.0140mol), triethylsilane (2.58g, 0.0222mol), ethanol (1.02g, 0.0222mol) and sufficient toluene to achieve a total volume of 133 mL. The reaction mixture was heated to 80 ℃ and DANBAABA (1.0mL of a 0.06M solution in dichloromethane) and [ bis (diisopropylphenylphosphine) (acrylonitrile) palladium acetate were added][ tetrakis (pentafluorophenyl) borate](1.0mL of a 0.02M solution in dichloromethane). After 18h, the reaction mixture was cooled and then 40mL of Amberlite GT-73(Rohm and Haas) and Diaion CRS02(Mitsubishi Chemical) resin beads were added. This slurry was shaken overnight. The resin beads were removed by filtration to give a colorless filtrate. The filtrate was concentrated by rotary evaporation and then added to 10-fold excess volume of hexane to precipitate the polymer. The polymer was collected by filtration and dried in a vacuum oven at 90 ℃. The yield was 24.6g (46%). Mw 4610; mn 3260. By using¹³After C NMR measurements, the HFANB to HEENB molar ratio was found to be 88: 12.

Synthetic example 25

Synthesis example 24 was repeated, except that the monomer internal/external form ratio was 70: 30. The yield was 19.9g (37%). Mw 6740; and Mn is 4580. By using¹³After C NMR measurements, the HFANB to HEENB molar ratio was found to be 86: 14.

Synthesis example 26

Synthesis example 24 was repeated, except that the monomer internal/external form ratio was 58: 42. The yield was 20.9g (39%). Mw 7140; mn is 4590. By using¹³After C NMR measurements, the HFANB to HEENB molar ratio was found to be 87: 13.

Dissolution Rate test method 1 for examples 1-23

The dissolution kinetics of polymer films formed with several of the polymers of examples 1-23 in an aqueous alkaline developer were studied with a Quartz Crystal Microbalance (QCM). The intrinsic frequency of the quartz crystal used in this study was about 5 MHz. A high resolution frequency counter and IBM PC were programmed with a Maxtek TPS-550 sensor probe and PI-70 drive and Phillips PM 6654. The instrument was controlled and data collected using a custom Lab-View software program. The polymer was dissolved in propylene glycol methyl ether acetate (1/5wt/wt) and the solution was filtered through a 0.2 μm filter. A polymer film was prepared on a1 "quartz plate by spin casting, baked at 130 ℃ for 60 seconds, and then the coated plate was mounted on a QCM probe. The dissolution rate of the polymer in 0.26N tetramethylammonium hydroxide (TMAH) (CD-26) was somewhat linear with time, so that the dissolution rate (. alpha./sec) could be calculated from the slope of the plot of thickness versus development time.

The results of these tests are shown in figure 3. The Dissolution Rate (DR) of each of the polymers of the above examples plotted in FIG. 3 is a function of the number average molecular weight (Mn) and the mol% exo-isomer of the HFANB monomer used in the polymerization. It should be noted that the DR of the homopolymers shown in the figures do not appear to be affected by the Mn (or Mw) of the polymer. That is, if the exo isomer concentration of the starting monomer is high (i.e., 42%), DR is low (3500-.

Dissolution Rate test example 2

The copolymers of Synthesis examples 24, 25 and 26 were dissolved in PGMEA to give a solid content of 20-25%.

The silicon wafer (SiliconQuest, <1, 0, 0>) was spin-cleaned with 1mL of Hexamethyldisilane (HMDS), spin-coated at 500rpm for 10sec, then spin-coated at 2000rpm for 60sec, and then baked at 130 ℃ for 90 sec. About 1mL of the filtered (0.2 micron) polymer solution was coated at the center of the wafer and spun as described above. The wafers were soft baked at 130 ℃ for 120sec to ensure that all casting solvent was removed.

Cauchy (Cauchy) parameters and film thickness of the samples were measured using a j.a.woollam M2000 ellipsometer.

Dissolution rates were tested with a reflectometer based dissolution rate detector, data collected and controlled with a custom made Lab-View system, and interferometric data collected using a single wavelength versus time relationship. The developer was aqueous tetramethylammonium hydroxide (Shipley, TMAH 2.38%). The samples were developed using the puddle technique, in which an aliquot of the developer was placed on the film and the film thickness was measured as a function of time. The slope of the thickness versus time curve will produce a dissolution rate, expressed in sec. The results of these tests are reported in table 2.

As with the DR data plotted in FIG. 3 discussed above, the dissolution rates of the polymers of examples 24, 25 and 26 appear to be more dependent on the exo isomer mol% in the starting HFANB monomer. It seems as if the higher the mol% of exo isomer, the lower the DR, regardless of the molecular weight.

Polymer mixtures and imaging

Poly (tert-butyl-2-trifluoromethylacrylate-co-5- [ (1, 1 ', 1-trifluoro-2 ' -trifluoromethyl-2 ' -hydroxy) propyl ] norborn-2-alkyl vinyl ether) (P (TBTFMA-VENBHFA) copolymer) and HFANB homopolymer (1/1wt/wt) (one of examples 12, 15, 16, 19, 21 and 23) were mixed by dissolving equal weight of each in propylene glycol methyl ether acetate to prepare a 10 wt% polymer solution. Di-tert-butylphenyl iodonium perfluorooctane sulfonate (4%) and tetrabutylammonium hydroxide (0.15%) were added to the polymer solution. The solution was filtered (0.2 μm). The solution was then spin coated, the resulting film baked at 130 ℃ for 60sec, exposed to 193nm radiation through a double chrome on glass mask, post-exposed baked at 130 ℃ for 90sec, and then developed with a commercial 0.26N tetramethylammonium hydroxide solution.

Referring to fig. 4 and 5, there are scanning electron micrographs of the spin-cast film as described above shown after exposure (120 nanometer (nm) lines and spaces) and image development. In FIG. 4, the micrograph is a higher Mn mixture, using the homopolymers of examples 23, 19 and 16. It can be seen that the image quality is best for the polymer mixture having the highest mol% of exo isomer. In FIG. 5, the micrograph is a lower Mn mixture, using the homopolymers of examples 21, 16 and 12. It can be seen that the image quality of all samples is relatively uniform, with no tendency for the image quality to be clearly visible and/or correspond to the exo-isomer mol%. Most notably, however, the best imaging results of fig. 4 are comparable to those of fig. 5, despite the large difference in molecular weight of the HFANB homopolymer used in the mixture. This result is unexpected, which indicates that: controlling the exo isomer mol% can provide more uniform imaging quality over a wide range of molecular weights. Thereby providing a wider process window for the actual imaging and photoresist composition.

The copolymers are represented by the following structural formula, wherein the percentages are relative concentrations of the individual monomers in the copolymer.

Therefore, from the above-described imaging effect, it can be said that: the best image quality is seen when the molecular weight of the HFANB homopolymer is high (see fig. 4), when the exo-isomer mol% of the HFANB starting polymer is highest (58/42). If the exo isomer mol% is low (90/10), the image is severely bridged.

If the molecular weight of the HFANB starting monomer is very low (FIG. 5), the performance of all mixtures appears to be uniformly good, independent of the exo isomer mol%. Thus, by providing the desired exo mole percent on at least one repeat unit of the polymer used in the photoresist composition, the dissolution rate differential can be controlled over a wide range of molecular weights, thereby improving good image quality.

TABLE 1

Examples	Yield of	Mw	Mn	CTA*	Peracid	Inside/outside shape	DR(_/sec)
								1	66％	11300	5440	H2	Is free of	44/56	4089
2	50％	6400	3630	C2H4	Is provided with	70/30	3916
								3	60％	12900	5930	C2H4	Is provided with	70/30	2741
4	60％	16300	8000	C2H4	Is provided with	70/30	3552
								5	62％	28000	12100	C2H4	Is provided with	70/30	3361
6	60％	36200	15500	C2H4	Is provided with	70/30	3516
								7	61％	17860	7270	H2	Is free of	70/30	2904
8	52％	7900	4150	H2	Is free of	70/30	3428
								9	80％	8870	4880	H2	Is free of	85/15	6432
10	76％	13600	5700	H2	Is free of	85/15	5801
								11	77％	11600	5820	H2	Is free of	85/15	6570
12	77％	4670	3120	Et3SiH	Is free of	90/10	6588
								13	72％	31230	14380	Et3SiH	Is free of	90/10	6486
14	76％	8980	5260	Et3SiH	Is free of	90/10	7300
								15	65％	16510	8530	Et3SiH	Is free of	90/10	6526
16	77％	5350	3270	Et3SiH	Is free of	78/22	6627
								17	87％	9030	5070	Et3SiH	Is free of	78/22	6045
18	89％	15700	7490	Et3SiH	Is free of	78/22	6740
								19	91％	22700	10600	Et3SiH	Is free of	78/22	6423
20	93％	31900	13700	Et3SiH	Is free of	78/22	6543
								21	73％	5770	3560	Et3SiH	Is free of	58/42	3920
22	91％	16400	7520	Et3SiH	Is free of	58/42	3850
								23	77％	28700	12900	Et3SiH	Is free of	58/42	3510

^*CTA stands for chain transfer agent

TABLE 2

Examples	Yield of	Mw	Mn	CTA	Inside/outside shape	DR(_/sec)
							24	46％	4610	3260	Et3SiH	90/10	1920
25	37％	6740	4580	Et3SiH	70/30	510
							26	60％	7140	4590	Et3SiH	48/52	460

Claims (3)

1. A photoresist composition comprising a polymer comprising at least one polycycloolefin derived repeat unit having a desired exo mole percent.

2. A method of improving the imaging properties of a photoresist composition comprising providing a polymer resin comprising polycyclic olefin derived repeat units having a desired exo mole percent.

3. A method of controlling the differential dissolution rate of a photoresist composition comprising providing a polymer resin comprising polycyclic olefin derived repeat units having a desired exo mole percent to the photoresist composition.