Feb.4,2021  119  US 2021/0033971 Al  [0211]  EUV Lithography Test  [0212]  Each of the resist compositions in Table 1 was spin  coated on a silicon substrate having a 20-nm coating of  silicon-containing spin-on hard mask SHB-A940 (Shin-Etsu  Chemical Co., Ltd., Si content 43 wt%) and prebaked on a  hotplate at 105°  C. for 60 seconds to form a resist film of 50  nm thick. Using an EUV scanner NXE3300 (ASML, NA  0.33,  a0.9/0.6,  quadrupole illumination), the resist film was  exposed to EUV through a mask bearing a hole pattern at a  pitch 46 nm (on-wafer size) and +20% bias. The resist film  was baked (PEB) on a hotplate at the temperature shown in  Table 1 for 60 seconds and developed in a 2.38 wt% TMAH  aqueous solution for 30 seconds to form a hole pattern  having a size of 23 nm.  [0213]  The resist pattern was observed under CD-SEM  (CG-5000, Hitachi High-Technologies Corp.). The exposure  dose that provides a hole pattern having a size of 23 nm is  reported as sensitivity. The size of 50 holes was measured,  from which a size variation  (3a)  was computed and reported  as CDU.  [0214]  The resist composition is shown in Table 1 together  with the sensitivity and CDU of EUV lithography.  [0210]  DAA (diacetone alcohol)  Acid generator: PAG-1 of the following structural formula  Quencher: Q-1 of the following structural formula  [0209]  PGMEA (propylene glycol monomethyl ether  acetate)  Organic Solvents:  [0208]  The components in Table 1 are as identified below.  [0207]  Positive resist compositions were prepared by dis› solving components in a solvent in accordance with the  recipe shown in Table 1, and filtering through a filter having  a pore size of 0.2 The solvent contained 100 ppm of  surfactant FC-4430 (3M). Notably, a carboxylic acid was  added in such an amount that a molar ratio of carboxyl group  on the carboxylic acid to nitrogen-containing group on the  polymer was  1: 1.  Acid  Polymer  generator  (pbw)  (pbw)  1 Polymer 1  PAG-1  (100)  (25.0)  2 Polymer 2  (100)  3 Polymer 3  (100)  4 Polymer 4  (100)  5 Polymer 5  (100)  6 Polymer 6  (100)  7 Polymer 7  (100)  8 Polymer 8  (100)  9 Polymer 1  PAG-1  (100)  (25.0)  10 Polymer 1  PAG-1  (100)  (25.0)  11 Polymer 9  (100)  12 Polymer 9  (100)  Polymer 1  PAG-1  (100)  (25.0)  PEB  Quencher  Carboxylic acid  Organic solvent temp. Sensitivity CDU  (pbw)  (pbw)  (pbw)  (" C.) (mJ/cm 2 )  (nm)  Example  iodoacetic acid  PGMEA (2,000) 95  29  3.1  (6.4)  DAA (500)  3-iodopropionic acid PGMEA (2,000) 95  29  2.3  (2.5)  DAA (500)  2-bromoisobutyric acid PGMEA (2,000) 95  26  2.6  (3.4)  DAA (500)  3-bromoisobutyric acid PGMEA (2,000) 95  23  2.3  (3.4)  DAA (500)  2-iodoisobutyric acid  PGMEA (2,000) 95  22  2.7  (4.0)  DAA (500)  2-iodoisobutyric acid  PGMEA (2,000) 95  24  2.7  (6.2)  DAA (500)  2-iodoisobutyric acid  PGMEA (2,000) 95  25  2.2  (6.2)  DAA (500)  2-iodoisobutyric acid  PGMEA (2,000) 95  24  2.4  (6.2)  DAA (500)  triiodoacetic acid  PGMEA (2,000) 95  26  2.7  (15.2)  DAA (500)  tribromoacetic acid  PGMEA (2,000) 95  28  2.8  (10.2)  DAA (500)  iodoacetic acid  PGMEA (2,000) 95  23  2.5  (4.7)  DAA (500)  Q-1  iodoacetic acid  PGMEA (2,000) 95  27  2.1  (1.00)  (4.7)  DAA (500)  Comparative Example  PGMEA (2,000) 95  35  5.6  DAA (500)  TABLE 1  [2] Preparation and Evaluation of Resist  Composition  Examples 1 to 12 and Comparative Examples 1 to  3  -continued  ’ ’  Q  Y-<~~  I  V  V  Q-1  PAG-1 