POLYMERS FROM BIS-ARYLCYCLOBUTENE GROUP CONTAINING MONOMERS THAT CURE THROUGH OTHER GROUPS AND METHODS FOR MAKING THE SAME

Abstract

The present invention provides organic solvent soluble or aqueous alkali soluble polymer composition comprising, in copolymerized form, one or more bis-arylcyclobutene monomers and one or more olefin or dienophile group containing second monomers, wherein the polymer is substantially free of (unreacted) arylcyclobutene groups. The compositions cure by a separate from the B-staging reaction which consumes substantially all of the arylcyclobutene groups in the composition; and they cure at temperatures below the cure temperature of less than 210 C., preferably, less than 180 C. The polymer compositions find use in making films or coatings and are aqueous or organic solvent developable when used in photolithography. Methods for making the polymer compositions are also provided.

Claims

1. An organic solvent soluble or aqueous alkali soluble polymer composition comprising, in copolymerized form, one or more bis-arylcyclobutene monomers and one or more olefin or dienophile group containing second monomers, wherein the polymer is substantially free of unreacted arylcyclobutene groups.

2. The polymer composition as claimed in claim 1, wherein the one or morebis-arylcyclobutene monomers is chosen from bis-benzocyclobutene (bis-BCB) or a bis-arylcyclobutene monomer containing one or more additional olefin or ethylenically unsaturated groups.

3. The polymer composition as claimed in claim 1, wherein the one or more bis-arylcyclobutene monomers is 1,3-bis(2-bicyclo[4.2.0]octa-1,3,5-trien-3-yl-ethenyl)-1,1,3,3-tetramethyldisiloxane (DVS-bis BCB).

4. The polymer composition as claimed in claim 1, wherein the one or more olefin group or dienophile group containing second monomers contains at least one group chosen from a vinyl, allyl, olefin or alkyne group.

5. The polymer composition as claimed in claim 1, wherein the one or more olefin group or dienophile group containing second monomers is (i) a monomer that has an acidic or hydrolyzable group chosen from carboxylic acids, anhydrides, carboxylic acid esters, amic acids, N-alkyl imides of dicarboxylic acids, N-aryl imides of dicarboxylic acids, N-imides of dicarboxylic acids, carboxylic acid esters, cyclic sulfones, sulfonic acids, acetoacetate, alkanols, amides, phenols, sulfonamides and (alk)oxysilanes.

6. The polymer composition as claimed in claim 1, wherein the one or more olefin group or dienophile group containing second monomers is (ii) a non-polar monomer chosen from cyclic olefins; dimers of cyclic olefins; dienes; aromatic vinyl group containing monomers having two or more vinyl groups; alkynes; linear and branched alkenes; allyl, alkyne or maleimide terminated polyimides, polyols or polyarylene ethers or polysiloxanes; or other ethylenically unsaturated group containing non-polar monomers having a normal boiling point of at least 150 C., wherein the composition can be developed by organic solvents.

7. The polymer composition as claimed in claim 1, further comprising a crosslinker, a curing agent or both.

8. The polymer composition as claimed in claim 5, further comprising a crosslinker chosen from a condensation crosslinker, a crosslinking monomer separate from the polymer, or mixtures thereof.

9. The polymer composition as claimed in claim 1, which dissolves in aqueous alkali and comprises, in copolymerized form, the bis-arylcyclobutene monomer, and one or more olefin group or dienophile group containing second monomers having an acidic group, the polymer composition further comprising a condensation crosslinker and cures via condensation reaction of the crosslinker with the acidic group.

10. The polymer composition as claimed in claim 1, wherein one or more olefin group or dienophile group containing second monomers contains a second dienophile group, and the composition can be crosslinked via thermally induced or light induced initiation reactions in the presence of a curing agent.

Description

[0084] EXAMPLES: The present invention will now be described in detail in the following, non-limiting Examples:

[0085] Unless otherwise stated all temperatures are room temperature (21-23 C.) and all pressures are atmospheric pressure (760 mm Hg or 101 kPa).

[0086] Notwithstanding other raw materials disclosed below, the following raw materials were used in the Examples:

[0087] Bis-BMI or BMI: Bisphenol bismaleimide or bismaleimide (unless otherwise indicated, FW 358.35);

[0088] BCB-AA: benzocyclobutene-acrylic acid;

[0089] Developer 1: 0.26N TMAH (tetramethyl ammonium hydroxide);

[0090] DPA: Diphenyl acetylene;

[0091] DVS or DVS-bis-BCB: (divinyl siloxane containing bisbenzocyclobutene monomer);

[0092] MAH: maleic anhydride;

[0093] MBA: 3-methoxy butylacetate solvent;

[0094] MI: maleimide;

[0095] NPM: N-Phenylmaleimide;

[0096] N541 epoxy: Mixture of glycidyl ethers of aromatic phenols EEW=171, and is a semi-solid-liquid;

[0097] GE38 epoxy: Mixture of glycidyl ethers of polyols, EEW=167, and is a liquid;

[0098] PI 46k: maleimide terminated polyimide, 46 kDa MW, solid.

[0099] PAC: diazonaphthoquinone photoactive compound, solid.

[0100] TPMA: Adhesion promoter, N-[3-(triethoxysilyl)propyl]maleamic acid.

[0101] The materials were analyzed in various disclosed ways, including, as follows:

[0102] Chemical resistance was tested by immersing a cured wafer or indicated product fragment in DMSO at 60 C. for 15 minutes, and measuring film thicknesses before and after.

[0103] Thermal stability was tested by running TGA analysis (Q500 TGA instrument, TA Instruments, New Castle, Del.) on cured wafer or indicated product scrappings. The sample was heated to 150 C. and held for 15 minutes to eliminate moisture, then finally heated to 400 C. at a rate of 10 C./min.

[0104] FT-ATR-IR spectroscopic analysis: ATR-FT-IR (Attenuated Total Reflection Fourier Transform Infrared) spectra were taken on a Thermo Scientific Nicolet 6700 FT-IR with a Smart DURASAMPIIR module (Thermo Fisher Scientific, Waltham, Mass.) to allow for ATR spectra to be obtained. The background spectrum was taken as air for all samples. No correction was applied. Samples were taken by covering the diamond crystal completely and acquiring and averaging four scans.

[0105] Mole Ratio Calculation: Moles of second monomer olefin group or dienophile groups to moles of unreacted arylcyclobutene groups was calculated from the starting number of moles of bis-arylcyclobutene monomer. The residual exotherm from B-staging was measured in J/g and compared to the total enthalpy in the bis-arylcyclobutene monomer (in J/g, for DVS it is 800 J/g, corresponding to 156 J/mmol of BCB). The ratio of residual exotherm to enthalpy gave a number of mmols of bis-arylcyclobutene monomer per gram of solids; this was multiplied by the total mass in grams of solid, to give total mmols of bis-arylcyclobutene monomer. This was compared to number of mmoles of second monomer added to give the mole ratio.

[0106] Example 1: In this example, the monomer mixture contains 1.9 moles of olefin groups per mole of BCB groups. This excess of moles of unreacted second monomer or offset stoichiometry (i) lowers the crosslink density, (ii) retards the molecular weight growth of the polymer and (iii) allows for a much more controlled polymerization. DVS-bis-BCB (10.0 g, 25.60 mmol), maleic anhydride (4.0 g, 40.79 mmol), Bis-F-BMI (1.0 g, 2.79 mmol) and phenothiazine (radical inhibitor) (0.2 g, 1.00 mmol) was added to a 3-neck 100 mL round bottom flask. 3-methoxy butylacetate (MBA, 17.0 g) and y-butyrolactone (GBL, 5.0 g) were then added to the flask. The 3-neck round bottom flask was then equipped with a reflux condenser and a J-Kem thermocouple (J-KEM Scientific, Inc., Saint Louis, Mo.). Septa were used to seal the flask, and nitrogen was then sparged through the mixture for 20 minutes. The reaction was then heated used a heating mantle to a target temperature of 175 C. After ca. 10 minutes, the solution reached ca. 100 C. and a red solution was obtained. The reaction was heated for a total time of 18 hours after which the solution was allowed to cool to RT. GPC and DSC analysis was performed. The GPC and DSC procedure was repeated for another 12 hours (30 hrs total), then another 6 hours (36 hrs total), then another 12 hours (48 hr total), then another 12 hours (60 hrs total), then another 64 hours (124 hrs total). The GPC and DSC analysis is shown in Tables 3 and 4, below. As a comparison, a conventional aqueous developable composition made from 100% of a BCB-AA adduct, the molecular weight growth profiles are shown in Table 4, below.

[0107] To tune the dissolution rate of the polymer, the anhydride functionality was used as a modular handle for functionalization. In this experiment, hydrolysis produced the corresponding diacid. This was confirmed via an FT-ATR-IR spectroscopic analysis. A at 1774 cm.sup.1 corresponding to the anhydride vibration decreased, whereas the bands that increased at ca. 3400 and 1712 cm.sup.1 corresponded to the carboxylic acid vibrations Alternatively, the anhydride can be cleaved by an alcohol to form the ester-acid. FT-ATR-IR spectroscopic analysis demonstrated this in an example using tert-butanol: that is decreasing at 1774 cm.sup.1 corresponds to the anhydride vibration, whereas the bands that are increasing at ca. 3400 and 1712 cm.sup.1 corresponds to the carboxylic acid/ester vibrations.

[0108] Example 2 Polymer From B-Staged Bis-Arylcyclobutene Monomer: 18 grams of a B-staged polymer (40 wt. % solids in 3-methoxy butylacetate solvent, made from 30 mole percent BCB-AA adduct and 70 mole percent DVS-bis-BCB) was added to a 3-neck 100 mL round bottom flask. Maleic anhydride (30.0 g, 305.9 mmol), phenothiazine (1.0 g, 5.0 mmol) and 3-methoxy butylacetate (11.2 g) was then added to the flask. The estimated mole ratio of Man to mols unreacted BCB was approx. 21:1. The 3-neck round bottom flask was then equipped with a reflux condenser and the J-Kem thermocouple. Septa were used to seal the flask, and nitrogen was then sparged through the mixture for 20 minutes. The reaction was then heated used a heating mantle to a target temperature of 175 C. for 12 hours. The reaction was then allowed to cool to room temperature. The resulting material was precipitated into a mixture of H.sub.2O/MeOH, washed with H.sub.2O, and then vacuum dried overnight. The polymer before and after maleic anhydride capping was put into a conventional AD-BCB formulation (including a polymer made from bis-arylcyclobutene monomer, N541 epoxy, PAC, and TPMA). These formulations were spin-coated onto 2 inch wafers at ca. 1000 rotations-per-minute for 30 seconds, and then soft-baked for 90 seconds at 120 C. The material was scratched off into pans for DSC analysis. DSC cure analyses without endcapping (where monomers are mixed and reacted without radical inhibitor) and after maleic anhydride capping (inventive Example 2) clearly demonstrated a significant decrease in the exothermic cure from BCB after capping is completed.

[0109] A control Example 2A was made in the same way as in Example 2, above, except that adducts of the bis-arylcyclobutene monomer (BCB or DVS) and the second monomer were not made before B-staging/polymerization. Instead, all monomers were mixed and polymerized or reacted at once. The exotherm at ca. 160 C. in the inventive polymer of Example 2 was due to epoxy-acid cure, whereas the exotherm at ca. 260 C. in the polymer of Example 2A wherein B-staging, polymerization and cure occur together in the presence of unreacted BCB, is due to BCB cure.

[0110] DSC Analysis of the B-Staged Polymer in Example 2

[0111] In Example 2A, without endcapping, the residual exotherm of the material in DSC was 306 J/g (on solids basis), and the material showed a large exotherm at 260 C. In Example 2,with endcapping, residual exotherm was <40 J/g (on solids basis) and the material gave no significant peak above 200 C.

[0112] Example 3: DVS-bis-BCB (30.0 g, 25.60 mmol), maleic anhydride (12.0 g, 40.79 mmol), Bis-F-BMI (3.0 g, 2.79 mmol) and phenothiazine (0.6 g, 1.00 mmol) was added to a 3-neck 300 mL round bottom flask. 3-methoxy butylacetate (MBA, 51.0 g) and -butyrolactone (GBL, 15.0 g) were then added to the flask. The 3-neck round bottom flask was then equipped with a reflux condenser and the J-Kem thermocouple. Septa were used to seal the flask, and nitrogen was then sparged through the mixture for 20 minutes. The reaction was then heated used a heating mantle to a target temperature of 175 C. The reaction was heated for a total time of 60 hours after which the solution was allowed to cool to RT. GPC and DSC analysis was then performed. The weight-average molecular weight was shown by GPC analysis to be 14,500 g/mol, and the DSC analysis shows a residual BCB cure of 50.9 J/g over a range of from 170 to 300 C. Residual cure was greatly reduced, evidencing low energy polymerization or B-staging; this figure corresponded to 25% of residual cure of the control polymer (B-staged polymer of 40 wt. % solids in 3-methoxy butylacetate solvent, made from 30 mole percent BCB-AA adduct and 70 mole percent DVS-bis-BCB) and 17% of the residual cure of an AD-BCB polymer. At this point, 34 grams of the inventive material was taken out of the flask to reserve as control. The rest of the material was hydrolyzed as follows. H.sub.2O (3.0 g, 166.7 mmol) was added to the flask, and the solution was heated for 23 hours at 100 C. FT-ATR-IR data confirmed hydrolysis as shrinkage of the anhydride peak and growth of the carboxylic acid peak. The hydrolyzed polymer was then put into a formulation of 64 wt. %, based on total solids weight percent, of the inventive polymer, 12 wt. % epoxy NPB-9 (2,1,5) in PAC, 19 wt. % DIC N541, and 5 wt. % TPMA. The formulation was tested for lithographic, thermal and chemical resistance properties.

[0113] The formulation was spin coated at 500RPM and soft baked at 120 C. for 2 minutes to make a wafer. Half of the wafer was then flood exposed (1000 mJ/cm.sup.2 using a broadband Suss Mask Aligner (Suss MicroTec SE, Garching, Del.) and then puddle developed using 0.26N tetramethylammonium hydroxide (TMAH) for 20 seconds. Film thicknesses before and after developments were measured giving exposed and unexposed dissolution rates of 0.405 m/sec and 0.100 m/sec, respectively. The results determined that a 30 second single puddle development was appropriate as the lithographic process. Another wafer was spin coated and soft baked under the same conditions. The wafer was then exposed with via patterns using an ASML200 Stepper (ASML Inc., Veldhoven, Netherlands, 1456 mJ/cm.sup.2 center dose, 52 mJ/cm.sup.2 step). The wafers were then cured at 250 C. for 1 hour.

[0114] The inventive material performed at a high level in terms of its photolithography, with clean development, high resolution with high aspect ratio and tunable angled side walls, no residual scumming, and no undercut. Additionally, chemical resistance testing showed a good 4.0% increase in thickness when immersed in DMSO at 60 C. for 15 minutes; and thermal stability testing gave a good 5 wt. % weight loss result at 347 C.

[0115] Mole Ratio Calculation: There were 35.68 mmols of BCB in the B-staged polymer before B-staging. After B-staging there was a 306 J/g residual exotherm. In DVS-bis-BCB, there is 800 J/g of enthalpy, corresponding to 156 J/mmol of BCB. Therefore, in the sample, there are approximately 2 mmols of BCB per gram of solids; 7.2 grams of solid, so there are 14.4 mmols of BCB. 305.9 mmoles of Man are added. The ratio is 306:14.4, which is approx. 21:1.

[0116] The materials above were reacted and tested, as follows:

[0117] Rxn time: B-staging reaction time until known exotherm is below 30 J/g.

[0118] Acid #: mmoles of acid per gram of total monomer as determined by stoichiometric calculation.

[0119] Film thickness: After spin coating the indicated coating at 1200 rpm for 30 seconds, then soft-baking at 120 C. for 90 seconds, as determined by light interference measurement.

[0120] B.D.R.: Base dissolution rate indicated developability in aqueous alkali measured in 0.26N TMAH (Developer 1) in water at room temperature immerse coated wafer for 30 to 60 seconds and measure film thickness before and after; acceptable is 0.1 or more.

[0121] BDR results are shown in Tables 1 and 2, below.

TABLE-US-00001 TABLE 1 Aqueous Developability Rxn Film DVS MAH time Acid # thickness B.D.R Example (mmol) (mmol) (hr) (mmol/g) (m) (m/s) 4* 15.00 0.375 31 0.13 1.6 n.a. 5* 15.00 0.375 16 0.13 n.a. See note a 6.sup.1 13.00 13.00 31 4.09 4.0 0.40 7.sup.2 7.50 30.00 31 10.22 10.5 0.58 *Denotes Comparative Example; a. When the film was put into CD-26, flaking and oily residue formed. Clean dissolution was not observed, and the silicon wafer was left with a scum residue. .sup.1Polymer in Example 6 was formed by heating the monomer mixture at 183 C. for a period of 18 hours; .sup.2Polymer in Example 7 was formed by heating the monomer mixture at 183 C. for a period of 18 hours. Polymerized using MBA as a solvent, the solvent made up 60 wt. % of the total mass. BHT was added at 1% by moles based on the amount of DVS-bis-BCB.

[0122] In all of Examples 4, 5, 6 and 7, butylated hydroxyltoluene (BHT) added at 1 mol %, based on total moles of added monomer. Samples A and AA were formed by heating the monomer mixture at 183 C. When heating the sample to what would be a reasonable point (e.g., the point at which we could use it for low cure applications), the sample gels as shown in second line above (code AA). Therefore, we decreased the time of B-staging to get a spin-coatable sample (this sample has a high temperature cure, code A). Dissolution in 0.26N tetramethylammonium hydroxide did not work well, it flaked and left a residue on the wafer product, i.e., scumming. The inventive Examples 6 and 7 comprise are polymers from endapped-BCB. Due to the significantly higher level of maleic anhydride (MAH), after heated for 31 hours, there is no gelling, but instead, a medium viscosity solution. The base dissolution rates are shown in the last column.

[0123] All polymers in shown Table 2, below were B-staged from the indicated monomer mixtures at 183 C. for 18 hours.

TABLE-US-00002 TABLE 2 More Aqueous Developable Polymer Compositions Rxn Film DVS MAH time Acid # thickness B.D.R Example (mmol) (mmol) (hr) (mmol/g) (m) (m/s) 8* 15.00 0.375 18 0.13 5.7 0.0 9 13.00 13.00 18 4.09 12.5 0.05 10 7.50 30.00 18 10.22 5.4 0.22 *Denotes Comparative Example.

[0124] Example 8 (comparative) showed no film thickness change after a 30 second and 60 second development. In contrast, both of inventive Examples 9 and 10 provided polymers that worked with aqueous development.

TABLE-US-00003 TABLE 3 DSC Exotherm at 260 C. for The Polymer of Example 1 Time (hr) Residual Exotherm (J/g) 30 65.4 36 58.1 48 44.7 60 30.3 124 5.8

[0125] Table 3, above, shows that the Polymer in Example 1 has substantially no unreacted arylcyclobutene groups after from 60 to 124 hours of B-staging.

TABLE-US-00004 TABLE 4 GPC in Polymerization Example 1: Example *1A: With Capping Without Capping Time Time (hr) MW (hr) MW 0 300 0 300 18 1492 2 785 30 2179 5 957 36 2520 7 1081 48 3863 24 2968 60 5016 27 3514 124 23970 43 12380

[0126] Example 1A is 30 mole % BCB-AA and 70 mole % DVS-bis-BCB, made in the same manner as the inventive polymer of Example 1, above, but without a radical inhibitor and without MAH. As shown in Table 4, above, the endcapped polymer of Example 1 versus the Comparative polymer of Example 1A, molecular weight builds substantially faster, evidencing a lower energy of reaction. Further, without endcapping, as in the polymer of Comparative Example 1A, heating for 45 hours leads to gel conditions.

[0127] Examples 11 to 13: Polymers from Monomer Mixtures

[0128] A series of polymers was formed from the given monomer mixtures below in Table 5, below, without B-staging. The monomer mixtures were reacted at 175 C. for the indicated time.

TABLE-US-00005 TABLE 5 Monomer Mixtures and Polymers DVS MAH Rxn time Mw (kDa), Res. Exo Example (g) (g) (hr) PDI (J/g) 11* 10.0 1.4 18 14.4, 5.3 131.4 12 10.0 2.5 24 13.1, 4.3 62.7 13 10.0 10.0 20 2.5, 2.1 12.1 *Denotes Comparative Example.

[0129] As shown in Table 5, above, the polymers made in accordance with the present invention in Examples 12 and 13 do not increase in molecular weight during polymerization because the B-staging reaction leads to endcapping rather than polymerization or curing by arylcyclobutene monomer. The resulting inventive polymers can be polymerized and cured without polymerization or cure of the arylcyclobutene groups well below the temperature of Comparative Example 11.

TABLE-US-00006 TABLE 6 Polymers From Multiple Monomers, All B-Staged Rxn Mw Res. DVS MAH NPM time/temp (kDa), Exo Example (g) (g) (g) (hr/ C.) PDI (J/g) 14 20.0 7.4 22.4 6/200 2.4, 7.0 24.9 15 10.0 4.8 18.1 6/200 2.3, 6.2 3.5 16 10.0 6.0 24.9 6/200 2.4, 3.7 1.3 17 10.0 7.2 31.6 8/200 4.3, 13.4 15.9 18 10.0 6.0 24.9 8/200 2.6, 9.3 14.4 19 10.0 6.0 24.9 24/190 2.5, 2.9 3.0 20 10.0 6.0 24.9 24/180 2.7, 3.2 32.3 *Denotes Comparative Example.

[0130] The formulations in Table 6, above, were made by B-staging the DVS monomer in the presence of the indicated second monomers and a radical inhibitor at a temperature and time period shown in Table 6; after this, further polymerization was not conducted.

[0131] As shown in Table 6, above, the polymers made in accordance with the present invention in Examples 14 to 20 did not gel during reaction because the B-staging reaction leads to endcapping rather than polymerization or curing by the bis-arylcyclobutene monomer. The residual exotherms are small, evidencing completion of B-staging. The resulting inventive polymers can be polymerized in the presence of curing agents and cured without polymerization or cure of the arylcyclobutene groups themselves and well below the temperature of the reaction of an arylcyclobutene group.

TABLE-US-00007 TABLE 7 Polymers From Multiple Monomers, All B-Staged Rxn Mw Res. DVS MAH BMI time/temp (kDa), Exo Example (g) (g) (g) (hr/ C.) PDI (J/g) 21 30.0 5.3 5.5 15/175 8.9, 4.3 117.1 22 10.0 4.0 1.0 124/175 24.0, 8.7 5.8 23 10.0 4.0 3.0 48/175 84.0, 25.7 28.7 24 30.0 12.0 3.0 60/175 14.5, 5.6 20.6 25 30.0 16.0 3.0 60/175 2.9, 1.9 10.0 26 10.0 5.3 1.0 72/175 8.0, 3.9 7.7 27 60.0 24.0 6.0 73/175 7.9, 3.9 25.6 28* 60.0 24.0 6.0 78/175 GEL n.a. 29 60.0 24.0 6.0 60/175 9.6, 6.5 40.9 *Denotes Comparative Example.

[0132] The formulations in Table 7, above, were made by B-staging the DVS monomer in the presence of the other monomers and a radical inhibitor at a temperature and time period shown in Table 7; after this, further polymerization was not conducted. As shown in Table 7, above, the polymers made in accordance with the present invention in Examples 21, 22, 24-27, and 29, did not gel during reaction because the B-staging reaction leads to endcapping rather than polymerization or curing by arylcyclobutene monomer. The resulting inventive polymers can be polymerized in the presence of curing agents and cured without polymerization or cure of the arylcyclobutene groups themselves and well below the temperature of Comparative Examples 4, 5 and 8, above. The one gelled polymer was cooked for longer than all but one example and was believed to have been mishandled.

TABLE-US-00008 TABLE 8 Polymers From Multiple Monomers, All B-Staged Rxn Mw Res. DVS MAH BMI NPM time/temp (kDa), Exo Example (g) (g) (g) (g) (hr/ C.) PDI (J/g) 30 30.0 10.0 3.0 10.0 69/175 4.8, 2.5 14.5 31 30.0 10.0 3.0 20.0 18/190 10.6, 5.1 17.0 32 10.0 6.0 0.9 24.0 24/185 3.1, 3.3 8.8 33 60.0 20.0 6.0 20.0 160/175 11.2, 5.6 5.7 34 60.0 20.0 6.0 20.0 112/175 8.8, 4.8 34.8 35 60.0 20.0 6.0 20.0 234/175 31.8, 14.4 5.7 36 90.0 30.0 9.0 30.0 72/175 19.2, 12.3 40.4 37 30.0 10.0 3.0 10.0 87/175 31.4, 15.5 25.6 *Denotes Comparative Example.

[0133] The formulations in Table 8, above, were made by B-staging the DVS monomer in the presence of the other monomers and a radical inhibitor at a temperature and time period shown in Table 8; after this, further polymerization was not conducted.

[0134] As shown in Table 8, above, the polymers made in accordance with the present invention in Examples 30 to 37 did not gel during reaction because the B-staging reaction leads to endcapping rather than polymerization or curing by arylcyclobutene monomer. The resulting inventive polymers can be polymerized in the presence of curing agents and cured without polymerization or cure of the arylcyclobutene groups themselves and well below the temperature of Comparative Examples 4, 5 and 8, above. Preferably, the amount of BMI as a second monomer should be below 0.25 molar equivalents of dienophile groups, based on the moles of the bis-arylcyclobutene monomers used to make the polymer.

TABLE-US-00009 TABLE 9 Polymers From Multiple Monomers, All B-Staged Rxn Mw Res. DVS MAH BMI NPM time/temp (kDa), Exo Example (g) (g) (g) (g) (hr/ C.) PDI (J/g) 38 10.0 6.0 3.9 .sup.a 24.0 24/185 3.2, 3.7 4.5 39 10.0 6.0 4.4 .sup.b 24.0 24/185 4.1, 4.1 19.3 40 30.0 10.0 12.6 .sup.a 10.0 87/175 8.7, 5.0 12.3 41 30.0 10.0 14.4 .sup.b 10.0 87/175 16.7, 11.2 20.8 .sup.a = BMI1500; .sup.b = BMI1700; *Denotes Comparative Example.

[0135] The formulations in Table 9, above, were made by B-staging the DVS monomer in the presence of the other monomers and a radical inhibitor at a temperature and time period shown in Table 9, after this, further polymerization was not conducted.

[0136] As shown in Table 9, above, the polymers made in accordance with the present invention in Examples 38-41 did not gel because the B-staging reaction leads to endcapping rather than polymerization or curing by arylcyclobutene monomer. The resulting inventive polymers can be polymerized in the presence of curing agents and cured without polymerization or cure of the arylcyclobutene groups themselves and well below the temperature of Comparative Examples 4, 5 and 8. Higher molecular weight BMI monomers had a much lower mole content of dienophile groups than the BMI used in Exs. 21-29, above, and did not pose a gelling problem.

TABLE-US-00010 TABLE 10 Polymers From Multiple Monomers and Maleimide (MI), All B-Staged Rxn DVS MAH MI NPM time/temp Mw (kDa)/ Example (g) (g) (g) (g) (hr/ C.) PDI 42 30.0 10.0 5.65 5.0 48/175 3.3/2.8

[0137] The formulation in Table 10, above, were made by B-staging the DVS monomer in the presence of the other monomers and a radical inhibitor at a temperature and time period shown in Table 10, further polymerization was not conducted.

[0138] The polymer in Example 42 showed adhesion to a silicon wafer without an adhesion promoter in a formulation comprising the 68% of polymer, 12% of the photoactive compound(s), 19% N541 epoxy, and a mixture of organic solvents. The formulation was spin-coated on both 200 mm silicon and copper wafers and baked at 120 C. to remove residual solvent. Upon exposure to the silicon wafer, no exposure popping was observed. After development with developer, post-adhesion to silicon was excellent with no developer undercut. Films on silicon and copper that were not exposed or developed were cured at 250 C. for 60 minutes under a nitrogen atmosphere. After the cure, the films were scored into 10 by 10 square grids with 1 mm pitch, and adhesion was checked with the tape peel test (ASTM D3359-17 standard, 2017) using a PAT-2000 tape peel kit (Gardco, Pompano Beach, Fla.). After testing, the scored films were placed in a pressure cooker for 2 days at 100% relative humidity and 121 C. After pressure cooking, the scored films were rechecked for tape peel and then scored in a new location and checked for tape peel. The films passed adhesion testing on both silicon and copper before and after pressure cooker tester.

[0139] In the following examples, formulations were formed from the indicated polymer and the indicated other materials, in a solids basis. The resulting materials were evaluated for use in photolithography.

[0140] EXAMPLE 43: A diamine (2,2-Bis(trifluoromethyl)benzidine), 8.39 g, 0.026 moles) and dimethylacetamide (60 g) was added to a flask under nitrogen. A dianhydride (4,4-(Hexafluoroisopropylidene)diphthalic anhydride, 10 g, 0.023 mol) was then added, resulting in a solution. After stirring at room temperature for 3 hours, maleic anhydride (0.72 g, 0.007 mol) was added. The reaction was stirred for 12 hours, at which point a mixture of acetic anhydride and triethyl amine was added. The reaction was precipitated into water, and then dried, giving a maleimide-capped polyimide (GPC analysis gives Mw=15.7 kDa, Mn=5.9 kDa and PDI=2.7). The maleimide-capped polyimide (4.96 g) was then used as a monomer and mixed with DVS-bis-BCB (30 g), maleic anhydride (10 g), N-phenylmaleimde (12 g), Bis-BMI (3 g) and solvent (73.5 g of MBA and 20 g of GBL). The reaction was heated at 175 C. for 28 hours, giving a polymer with Mw=8.8 kDa and Mn=3.1 kDa (PDI=2.8). The polymers were then completely hydrolyzed to give polymers comprising diacids. This polymer composition was used in Examples 44 and 45 for negative Tone Lithography.

[0141] In Examples 44 and 45, a negative Tone Lithography composition was formulated with epoxy, as shown in Table 11, below, to comprise the polymer composition from the previous paragraph, a mixture of generic multifunctional (meth)acrylates including SR454 triacrylate (Sartomer, Exton, Pa.), a mixture of epoxies including N541 and GE38, and a UV-absorbing photoinitiator including Irgacure 379 initiator (BASF, Ludwigshafen, Del.). The formulations comprising polymer compositions of hydrolyzed (i) acidic second monomer, in copolymerized form, were cast as a film by spin-coating onto a 200 mm silicon wafer and baking at 120 C. and gave the indicated physical properties.

TABLE-US-00011 TABLE 11 Negative Tone Lithography Avg. Ultimate Func Acid Epoxy Tensile (MPa)/ Example %.sup.a #.sup.b Epoxy %.sup.c Modulus (GPa).sup.d 44 100% 3.34 N541 100% 86/2.5 45 100% 4.4 GE38 100% 52/1.4 .sup.a= post-polymerization functionalization (hydrolysis) level; .sup.b= calculated acid #; .sup.c= epoxy %, as solids by mass compared to polymer; .sup.d= Free standing films were obtained by immersing cured films on copper wafers in 10-30% aqueous ammonium persulfate. After the copper was etched, the free standing films with known dimensions (10 25.4 mm with thickness from 5-15 microns) were placed in the clamps of an Instron (lnstron Corp., Norwood, MA), and elongated until broken. Multiple samples were run to obtain the average ultimate tensile strength (MPa) and Modulus (GPa).

[0142] The compositions in Table 11, above dissolved in aqueous media except where cured and so were aqueous developable. The compositions which were cured by light did not dissolve.

[0143] In Examples 46 to 54, a positive tone lithography composition was formulated to comprise the indicated BCB-Capped polymer, multifunctional epoxies and diazonaphthoquinone photoactive compounds. The polymers indicated in Table 12, below, were from the indicated Example. The polymers were then esterified, partly or completely hydrolyzed to give polymers comprising diacids or ester acids. The polymers and part of the formulations are shown in Table 12, below. The formulations were cast as a film by spin-coating onto a 200 mm silicon wafer and baking at 120 C. which had the indicated good physical film properties.

TABLE-US-00012 TABLE 12 Positive Tone Lithography Avg. Ultimate Polymer Func Acid Epoxy Tensile (MPa)/ Example Ex. %.sup.a #.sup.b Epoxy %.sup.c Modulus (GPa).sup.d 46 41 50% 3.26 GE38 100% 81/2.3 47 41 100% 3.26 GE38 100% 71/2.1 48 41 100% 3.26 GE38 100% 78/2.2 49 41 100% 3.26 GE38 100% 74/2.2 50 41 100% 3.26 GE38 100% 74/2.2 51 41 100% 3.26 GE38 100% 88/2.5 52 41 100% 5.44 N541 100% 96/2.1 53 24 100% 5.44 GE38 100% 81/2.1 54 23 100% 4.8 GE38 100% 82/2.2 .sup.a= post-polymerization functionalization level; .sup.b= calculated acid #; .sup.c= epoxy %, as solids bymass compared to polymer; .sup.d= see fn d of Table 11, above.

[0144] The compositions above dissolved in aqueous media except where not exposed to light and so were not aqueous developable. The compositions which were exposed to light dissolved; unexposed compositions did not dissolve.

[0145] In Examples 55 to 61, a positive tone lithography composition was formulated to comprise the indicated BCB-Capped polymer, multifunctional epoxies and diazonaphthoquinone photoactive compounds. The indicated polymers in Table 13, below, were formed as described in the indicated Example, above, and were then completely hydrolyzed to give polymers comprising diacids. The formulations were cast as a film by spin-coating onto a 200 mm silicon wafer and soft-baking at 120 C., which had the indicated good physical film properties.

TABLE-US-00013 TABLE 13 Positive Tone Lithography Avg. Ultimate Polymer Func Acid Epoxy Tensile (MPa)/ Example Ex. %.sup.a #.sup.b Epoxy %.sup.c Modulus (GPa).sup.d 55 30 100% 3.85 N541 100% 109/2.6 56 30 100% 3.85 N541 50% 105/2.5 57 30 100% 3.85 GE38 100% 80/2.2 58 30 100% 3.85 GE38 50% 91/2.2 59 30 100% 3.85 N541/ 100% 93/2.3 GE38 (1:1) 60 30 100% 3.85 N541/ 50% 95/2.3 GE38 (1:1) 61 30 100% 3.85 GE38 100% 82/2.2 .sup.a= post-polymerization functionalization level; .sup.b= calculated acid #; .sup.c= epoxy %, as solids by mass compared to polymer; .sup.d= see fn d in Table 11, above,

[0146] The compositions shown in Table 13, above, dissolved in aqueous alkali (Developer 1) and when exposed to light; unexposed compositions did not dissolve. Physical film properties were good.

TABLE-US-00014 TABLE 14 Reaction of DVS-BCB and Non-polar monomers (diphenyl acetylene) g g g Solvent g % Example BCB DPA BCB DPA solids g MBA soln solids 62 1 2.0 1.161 1.072 2.233 3.373 5.606 39.8% 63 1 3.9 0.792 1.424 2.216 3.312 5.528 40.1% 64 1 7.8 0.499 1.782 2.281 3.427 5.708 40.0%

[0147] Examples 62 to 64: In Examples 62 to 64, the monomer mixture indicated in Table 14, above, contained between a molar ratio of from 1:2 to 1:8 of alkyne groups per mole of BCB groups. The excess moles of unreacted second monomer or offset stoichiometry (i) lowers the crosslink density, (ii) retards the molecular weight growth of the polymer and (iii) allows for a much more controlled polymerization. DVS-bis-BCB (1.161 g, 2.97 mmol), and diphenyl acetylene (1.072 g, 6.01 mmol) were added to a 10 ml glass test tube along with a magnetic stir bar. 3-methoxy-1-butylacetate (MBA, 5.606 g) was added to the test tube and a rubber 8mm septum was used to seal the test tube. Polymers in Examples 63 and 64 were prepared in the same manner as the polymer of Example 62 and in the proportions indicated in Table 14, above. Each of the polymers was heated using an EZ Max reactor an adapter to allow simultaneous heating of 4 test tubes. The thermocouple for the reaction was located in the 4th test tube which contained only MBA solvent and a magnetic stir bar. The reaction temperature was set to 172 C. and the solution was heated to temperature at a rate of 5 C./minute. After ca. 30 minutes, the solution reached ca. 172 C. and a pale yellow solution was obtained. The reaction was heated for a total time of 62 hours after which the solution was allowed to cool to RT. GPC and DSC analysis was performed. The molecular weight and residual cure for all three examples are shown in Table 15, below.

TABLE-US-00015 TABLE 15 Results from reaction of DVS- BCB with Non-polar monomers Example Mw (GPC) Residual Cure (DSC) 62 Gelled NM 63 165K none 64 131K none