21  US 9,541,834 B2  22  filtered by 0.2 um Nylon filter. A 60 run film of CTOl was  spin-coated on resist with 45 run 1: 1 line and space patterns,  baked at 70°  C., and developed in 2.38% TMAH developer  for 12 s with TEL Lithus GP nozzle.  CD shrink than the pyridinium TAG, and, without wishing  to be bound by theory, it is believed that this is due, at least  in part, to the lower pKa of3-fluoropyridine vs. pyridine (at  similar boiling point).  2.324 g copolymer of t-butyl acrylate/methacrylic acid 10  (7 /3 of mole ratio), 0.126 g of Pyridinium perfluorobutane› sulfonate, 19.51 g decane and 78.04 g 2-methyl-1-butynol  were mixed until all components dissolved and then filtered  by 0.2 um Nylon filter. A 60 run film of CTO2 was  spin-coated on resist with 45 run 1: 1 line and space patterns, 15  baked at 70°  C. and developed in 2.38% TMAH developer  for 12 s with TEL Lithus GP nozzle.  2.323 g copolymer of t-butyl acrylate/methacrylic acid  (7/3 of mole ratio), 0.127 g of Pyridazinium perfluorobu- tanesulfonate, 19.51 g decane and 78.04 g 2-methyl-1- butynol were mixed until all components dissolve and then  filtered by 0.2 um Nylon filter. A 60 run film of CTOl  (Example 3) was spin-coated on resist with 45 run 1:1 line  and space patterns, baked at 70°  C. and developed in 2.38%  TMAH developer for 12 s with TEL Lithus GP nozzle.  2.344 g copolymer of t-butyl acrylate/methacrylic acid  (7 /3 of mole ratio), 0.106 g of Ammonium perfluorobutane› sulfonate, 19.51 g decane and 78.04 g 2-methyl-1-butynol  were mixed until all components dissolve and then filtered  by 0.2 um Nylon filter. A 60 run film of CTO2 was  spin-coated on resist with 45 run 1: 1 line and space patterns,  baked at 70°  C. and developed in 2.38% TMAH developer  for 12 s with TEL Lithus GP nozzle.  Results are set forth in Table 1.  The CD shrink values shown in Table 1 confirm that the  CTO composition with an ammonium TAG (Example 6)  exhibits no CD shrink at this temperature, whereas the  pyridinium TAG (CTO2) shows 11.5 run shrink. Without  wishing to be bound by theory, it is believed that the lack of  CD shrink in the composition with the ammonium TAG is  due to the high pKa of ammonia (9.25), whereas the pyri- dinium TAG of Example 5 has a lower pKa. The 3-fluoro› pyridinium TAG (CTOl, Example 3) shows an even greater  -continued  2.  The method of claim  1  wherein B is selected from the  group consisting of:  in which  (K)(BH)+  (I)  A- is the anion of an organic or inorganic acid having a  pKa of not more than 3; and  (BHt is the monoprotonated form of a nitrogen-contain› ing base B having a pKa between  O  and 5.0, and a  boiling point less than 170°  C.;  d) heating the chemical trim overcoat composition layer;  and  e) developing the photoresist layer to provide a photore› sist relief image.  Example 6  CTO Comparative Example (for Comparison with  CTO2)  Example 5  CTO Comparative Example (for Comparison with  CTOl)  c) applying over the exposed photoresist composition  coating layer a coating layer of a chemical trim over› coat composition comprising a thermal acid generator  of formula (I);  b) exposing the photoresist layer to activating radiation  and developing the exposed photoresist layer to provide  a photoresist relief image;  a) applying a coating layer of a chemically amplified  photoresist composition on a substrate;  What is claimed is:  1.  A method for providing a photoresist relief image,  comprising:  Comparative Example 5 uses a TAG made from  pyridazine, a base with a pKa similar to that of 3-fluoro› pyridine, but a 100°  C. higher boiling point. As shown in  Table 1, the pyridazinium TAG results in relatively small  shrink.  Example 4  Chemical Trim Overcoat Composition (CTO2)  TABLE 1  pKa  TAG  CTO  b.p. (base)  (base)  Final CD  No CTO  NA  NA  NA  45.7 nm  3-Fluoropyridinium CTO 1  108° C.  2.8  26.4 nm  PFBuS  Pyridinium PFBuS  CTO 2  115° C.  5.14  34.3 nm  Pyridazinium PFBuS Comparative CTO 1  208° C.  3.1  40.6 nm  Ammonium PFBuS Comparative CTO 2  -33° C.  9.25  45.8 nm  LI.CD  NA  19.3 nm  11.5 nm  5.1 nm  -0.1 nm 