US 10,101,653 B2  128  127  TABLE 2  Acid  PEB  Polymer  generator  Base  Organic solvent  temp. Sensitivity CDU  (pbw)  (pbw)  (pbw)  (pbw)  (" C.)  (mJ/cm 2 )  (nm)  Example  2-1  Polymer 3  PAG 8  Quencher 2  PGMEA (400)  75  71  3.0  (100)  (6.0)  (3.00)  CyH (2,000)  PGME (100)  2-2  Polymer 3  PAG 9  Quencher 2  PGMEA (400)  75  21  3.0  (100)  (7.0)  (3.00)  CyH (2,000)  PGME (100)  2-3  Polymer 3  PAG 10  Quencher 2 PGMEA (2,000)  75  23  2.8  (100)  (7.0)  (3.00)  DAA (500)  2-4  Polymer 3  PAG 10  Quencher 2 PGMEA (2,000)  75  23  2.7  (100)  (7.0)  (3.00)  DAA (500)  2-5  Polymer 3  PAG 11  Quencher 2 PGMEA (2,000)  75  25  2.7  (100)  (10,0)  (3.00)  DAA (500)  2-6  Polymer 4  PAG 16  Quencher 2 PGMEA (2,000)  70  26  2.5  (100)  (10.0)  (3.00)  DAA (500)  2-7  Polymer 3  PAG 17  Quencher 2 PGMEA (2,000)  75  25  2.3  (100)  (10.0)  (3.00)  DAA (500)  2-8  Polymer 3  PAG 18  Quencher 2 PGMEA (2,000)  75  26  2.7  (100)  (10.0)  (3.00)  DAA (500)  2-9  Polymer 3  PAG 19  Quencher 2 PGMEA (2,000)  75  25  2.6  (100)  (10.0)  (3.00)  DAA (500)  2-10  Polymer 3  PAG20  Quencher 2 PGMEA (2,000)  75  21  2.3  (100)  (10.0)  (3.00)  DAA (500)  2-11  Polymer 3  PAG21  Quencher 2 PGMEA (2,000)  75  17  2.1  (100)  (10.0)  (3.00)  DAA (500)  2-12  Polymer 3  PAG22  Quencher 2 PGMEA (2,000)  75  18  2.2  (100)  (10.0)  (3.00)  DAA (500)  2-13  Polymer 3  PAG23  Quencher 2 PGMEA (2,000)  75  16  2.3  (100)  (10.0)  (3.00)  DAA (500)  Comparative  2-1  Polymer 3  C-PAG4  Quencher 2  PGMEA (400)  85  30  4.0  Example  (100)  (6.0)  (3.00)  CyH (2,000)  PGME (100)  It  is demonstrated in Tables  1  and 2 that resist composi› tions comprising a sulfonium or iodonium salt of iodinated  phenoxy or iodinated phenylalkoxy-containing fluorinated  sulfonic acid within the scope of the invention offer a high  sensitivity and improved LWR and CDU.  Japanese Patent Application No. 2016-155516 is incor› porated herein by reference.  Although  some  preferred  embodiments  have  been  described, many modifications and variations may be made  thereto in light of the above teachings.  It  is therefore to be  understood that the invention may be practiced otherwise  than as specifically described without departing from the  scope of the appended claims.  The invention claimed is:  1.  A resist composition comprising a base polymer and an  acid generator containing a sulfonium salt having the for› mula  (1-1)  or an iodonium salt having the formula (1-2):  wherein R  1  is each independently a hydroxyl, C$_{1 }$-C$_{20 }$ straight, branched or cyclic alkyl or alkoxy group, C$_{2}$ -C$_{20 }$ straight, branched or cyclic acyl or acyloxy group, fluorine,  chlorine, bromine, amino, or alkoxycarbonyl-substituted  amino group,  R 2  is each independently a single bond or C$_{1}$-C$_{4 }$ alkylene  group,  R 3  is a single bond or C$_{1 }$-C$_{20 }$divalent linking group when  p=l, or a C$_{1 }$-C$_{20 }$tri- or tetravalent linking group when  p=2 or 3, the linking group optionally containing an  oxygen, sulfur or nitrogen atom,  Rf 1  to R:t4 are each independently hydrogen, fluorine or  trifluoromethyl, at least one ofRf$^{1 }$to R:t4 being fluorine  or trifluoromethyl, or Rf 1  and Rf 2 , taken together, may  form a carbonyl group,  R 4 , Rs, R 6 , R 7  and R 8  are each independently a C$_{1}$-C$_{12 }$ straight, branched or cyclic alkyl  group,  C$_{2}$ -C$_{12 }$ straight, branched or cyclic alkenyl group,  CcC$_{20 }$ aryl  group or C$_{7}$-C$_{12 }$ aralkyl or aryloxyalkyl group, in  which at least one hydrogen may be substituted by a  hydroxyl, carboxyl, halogen, cyano, oxo, amide, nitro,  sultone, sulfone, or sulfonium salt-containing moiety,  or in which an ether, ester, carbonyl, carbonate or  sulfonic acid ester moiety may intervene in a carbon› carbon bond, or R 4  and Rs may bond together to form  a ring with the sulfur atom to which they are attached,  m is an integer of  1  to 5, n is an integer of O to 3, and p  is an integer of  1  to 3.  2.  The resist composition of claim  1,  further comprising  an organic solvent.  3.  The resist composition of claim  1  wherein the base  polymer comprises recurring units having the formula (al)  or recurring units having the formula (a2):  (1-1)  (1-2) 