19  US 9,383,646  B2  20  Synthesis of (3-phenol-1-propyl  malonate )-methano-[ 60]fullerene ( 4)  In a 50 mL round bottom flask, 3 was dissolved in dichlo› romethane (10 mL) and stirred under nitrogen. Triflic acid  (0.1 mo!%) was added and stirred for 4 hours. The solvent  was removed under vacuum and the resulting residue 4 was  obtained and characterized by $^{1 }$H NMR and MALDI MS.  Synthesis of ((3-phenol-1-propyl)-(3-( 4-t-butoxycar› bonyl)-phenyl-1-propyl) malonate) methano-[60]  fullerene  In a 50 mL round bottom flask, 3 was dissolved in dichlo› romethane (10 mL) and stirred under nitrogen. Triflic acid  (0.1 mo!%) was added and stirred for 0.5 hours to partially  hydrolyze the 4-t-butoxycarbonyl groups. The solvent was  removed under vacuum and the resulting residue 4 was  obtained and characterized by $^{1}$H NMR and MALDI MS.  Into 100 mL of propylene glycol monomethyl ether  (PGME) was added 0.25 g of methanofullerene I, 0.50 g of  poly[(o-cresyl glycidyl ether)-co-formaldehyde] and 0.25 g  oftriphenylsulfonium hexafluoroantimonate and stirred for 1  hr at room temperature. The composition was applied to a  silicon wafer and spin coated at 500 rpm for 5 sec followed by  2000 rpm for 60 sec. The coated wafer was then heated on a  hot plate at 7 5°  C. for 5 min to give a film of approximately 25  mn. The wafer was imagewise exposed to synchrotron based  EUV light at 13-14 mn wavelength at 31.2 mJ/cm $^{2 }$and post  exposure baked at 90°  C. for 3 min. The unexposed areas were  removed by puddle development in a 50:50 blend of  monochlorobenzene and isopropyl alcohol for 20 sec fol- lowed by an isopropyl alcohol rinse. FIG.  1  shows the result› ing 22 mn lines and spaces for example 1.  Example 1 was repeated but 150 mL of PGME was used to  reduce the solids content. The resulting film thickness was 18  mn and the exposure was 21.2 mJ/cm 2 .  FIG.  2  shows the  resulting 18 mn lines and spaces for example 2.  Example 1 was repeated using methanofullerene II in place  of methanofullerene I. A 48 mJ/cm 2  exposure dosage was  used. FIG.  3  shows the resulting 25 mn lines and spaces for 50  example 3.  Example 1 was repeated using an E-beam exposure in  place of 13-14 mn exposure. Area dose testing established a  sensitivity of 90 µC/cm2  at 30 keV. For high resolution pat› terning a line dose of 575 pC/cm was applied at a nominal  half-pitch of 50 mn, given lines of -20 mn with -30 mn  spaces. FIG.  4  shows the resulting lines and spaces for  example 4.  Example 3 was repeated using an E-beam exposure of 90  µC/cm 2  at 30 keV in place of 13-14 mn exposure. For high  resolution patterning a line dose of 575 pC/cm was applied at  a nominal half-pitch of 50 mn, given lines of-20 mn with-30  mn spaces FIG.  5  shows the resulting lines and spaces for the  example 5.  The formulation of Example 1 was repeated using 0.125 g  of methanofullerene I and 0.125 g of a methanofullerene  having tetraethylene glycol esters capped with acetic acid to  provide acetate esters. The composition was applied to a  silicon wafer and spin coated at 500 rpm for 5 sec followed by  2000 rpm for 60 sec. The coated wafer was then heated on a  hot plate at 75°  C. for 5 min to give a film of approximately 25  mn. The wafer was imagewise exposed to 40 µC/cm 2  of  E-beamradiationand post exposure baked at 90°  C. for3 min.  For high resolution patterning a line dose of 600 pC/cm was  applied at a nominal half-pitch of 50 mn, given lines of -20  mn with -30 mn spaces The unexposed areas were removed  by puddle development in a 50:50 blend ofmonochloroben- zene and isopropyl alcohol for 20 sec followed by an isopro› pyl alcohol rinse. FIG.  6  shows the resulting lines and spaces  for example 6.  Into 100 mL of propylene glycol monomethyl ether  (PGME) was added 0.50 g of polyhydroxystyrene, 1.00 g of  poly[(o-cresyl glycidyl ether)-co-formaldehyde] and 0.50 g  oftriphenylsulfonium hexafluoroantimonate and stirred for 1  hr at room temperature. The composition was applied to a  silicon wafer and spin coated at 500 rpm for 5 sec followed by  2000 rpm for 60 sec. The coated wafer was then heated on a  hot plate at 70°  C. for 5 min to give a film of approximately 80  mn. The wafer was imagewise exposed to 30 ke VE-beam and  post exposure baked at 90°  C. for 2 min. The unexposed areas  were removed by puddle development in a 50:50 blend of  monochlorobenzene and isopropyl alcohol for 20 sec fol› lowed by an isopropyl alcohol rinse. A line dose of 118 pC/cm  was applied, given an isolated line of -20 mn. FIG.  7  shows  the resulting line for example 7.  Example 7 was repeated using 0.5% polyhydroxystyrene  which was 95.5% protected with t-BOC in place of the poly› hydroxystyrene. A line dose of 118 pC/cm was applied, giv› ing an isolated line of-22 mn. FIG.  8  shows the resulting line  for example 8.  Into 100 mL of ethyl lactate was added 0.25 g of polyhy› droxystyrene, 0.50 g of poly[(o-cresyl glycidyl ether)-co› formaldehyde] and 0.25 g of triphenylsulfonium hexafluoro- antimonate and stirred for 1 hr at room temperature. The  composition was applied to a silicon wafer and spin coated at  500 rpm for 5 sec followed by 1200 rpm for 80 sec. The coated  wafer was thenheatedonahotplate at 70°  C. for 5 min to give  a film of approximately 30 mn. The wafer was imagewise  exposed to 30 keV E-beam and post exposure baked at 110°  C. for 2 min. The unexposed areas were removed by puddle  development in a 50:50 blend of monochlorobenzene and  isopropyl alcohol for 20 sec followed by an isopropyl alcohol  rinse. A line dose of 88 pC/cm was applied at a nominal  half-pitch of 25 mn, given lines of -20 mn with -30 mn  spaces. FIG.  9  shows the resulting lines and spaces for the  example 9.  Composition Example 5  Composition Example 4  Composition Example 3  Composition Example 2  Composition Example 1  Composition Example 8  Composition Example 9  Composition Example 7  Composition Example 6 