181  US 9,958,775 B2  182  invention with an electron beam or extreme ultraviolet rays  (EUV). The exposure is conducted so that the exposure  amount is, in the case of an electron beam, about 0.1 to 20  µC/cm 2 ,  and preferably about 3 to 10 µC/cm 2 ,  and in the  case of extreme ultraviolet rays, about 0.1 to 20 mJ/cm 2 ,  preferably about 3 to 15 mJ/cm 2 .  Subsequently, a pattern is  formed by performing heating after exposure (Post Exposure  Bake) at 60 to 150°  C. for 1 to 20 minutes on a hot plate and  preferably at 80 to 120° C. for 1 to 10 minutes, and  developing, rinsing and drying. The developer is a 0.1 to 5%  by mass, and preferably 2 to 3% by mass alkaline aqueous  solution of tetramethylammonium hydroxide (TMAH), tet› rabutylammonium hydroxide (TBAH), and the like, and  development is carried out by a routine method such as a  dipping method, a puddle method or a spray method, for 0.1  to 3 minutes, and preferably 0.5 to 2 minutes. An appropriate  amount of alcohols and/or a surfactant may also be added to  the alkali developer. Thus, in a case where the composition  of the present invention is a negative-tone composition  which is used for the formation of a negative-tone pattern,  a film of the non-exposed portion is dissolved and it is  difficult for the exposed portion to be dissolved in a devel› oper since the compound (A) is cross-linked, and in a case  where the composition of the present invention is a positive› tone composition which is used for the formation of a  positive-tone pattern, the exposed portion is dissolved in a  developer and it is difficult for the non-exposed portion to be  dissolved in a developer and a objective pattern is formed on  a substrate.  Below, the present invention will be described in further  detail with reference to Examples, but the contents of the  present invention are not limited thereto.  As a cross-linking group-containing photo-acid generator,  compounds (A-1) to (A-29) shown in Table 1 described  below were synthesized as below.  EXAMPLES  [Synthesis of Compound A]  <Synthesis of Compounds (A-1) to (A-29)>  Synthesis Example 1: Synthesis of Compound  (A-1)  0-ffi-O  F-~  ~-F  II  II  0  F  0  3  (A-la)  F-~  ~-0  0-ffi-O  II  II  0  F  0  3  (A-lb)  0- 0- [Chem. 102]  0- Nao-~  ~-o  0-ffi-O  II  II  0  F  0  3  0- (A-le)  (())  0-ffi-O  y  II  II  s+  -o-S  S-0  II  II  0  F  0  3  (A-1)  0- 0- -continued  (Synthesis of A-1 b)  After 7 .5 g of 2,5-di(methoxymethyl)-4-t-butylphenol  was dissolved in 20 mL of tetrahydrofuran and 60 mL of  triethylamine was added thereto, temperature was cooled  with ice to 0°  C. to obtain the reaction solution. Next, the  solution in which 10 g of 1,1,2,2,3,3-heptafluoropropane-l,  3-disulfonyl fluoride was dissolved in 10 mL oftetrahydro› furan, was added dropwise into the reaction solution and was  stirred for 8 hours. 100 mL of ethyl acetate and 100 mL of  distilled water were added to the obtained reaction solution  and the obtained solution was moved to a separating funnel  and the aqueous layer was removed. Thereafter, the organic  layer was washed with 200 mL of distilled water for three  times, and then the organic layer was condensed to obtain 16  g of a compound (A-lb).  $^{1}$H-NMR (CDC1$_{3}$ :  ppm)  Ii:  1.33 (9H, s), 3.41 (6H, s), 4.58  (4H, s), 7.50 (2H, s)  $^{19}$H-NMR (CDC1$_{3}$ :  ppm)  Ii:  -118.457 (2F, t, J=15.2 Hz),  -113.874 (2F, t, J=15.2 Hz), -108.212 (2F, t, J=15.2 Hz).  16 g of A-lb was dissolved in 50 mL oftetrahydrofuran,  50 mL of methanol and 50 mL of IN of sodium hydroxide  was added thereto, and the mixture was stirred at room  temperature. After the reaction ends, the obtained reaction  solution was condensed under reduced pressure and 100 mL  of ethyl acetate and 100 mL of distilled water were added  thereto. Next, the obtained solution was moved to a sepa› rating funnel and the aqueous layer was removed. Thereaf› ter, the organic layer was washed with 200 mL of distilled  water for three times, and then the organic layer was  condensed. After the concentrate was purified by using a  silica gel colurmi chromatography ( eluent: ethyl acetate) and  a solvent was distilled off at reduced pressure, 16 g of a  compound (A-le) was obtained by performing vacuum  drying.  $^{1}$H-NMR (CDC1$_{3}$ :  ppm)  Ii:  1.28 (9H, s), 3.28 (6H, s), 4.50  (4H, s), 7.42 (2H, s)  (Synthesis of A-le) 