251  US 9,291,896 B2  252  As apparent from Table 4 above, in Comparative Examples  2-1 and 2-2 using Resin (Ab’-1) and Resin (Ab’-2) containing  the repeating unit represented by formula ( 1) but not contain› ing the repeating unit represented by formula (A), the sensi› tivity and the resolution of an isolated line pattern were poor,  the pattern profile was reverse tapered, the PEB temperature  dependency was high, and the etching resistance was low. In  Comparative Examples 2-3 and 2-4 using Resin (Ab’-3) and  (Ab’-4) containing the repeating unit represented by formula  (A) but not containing the repeating unit represented by for- mula (1 ), the PEB temperature dependency was high in par› ticular, the pattern profile was tapered, and the resolution of  an isolated line pattern was poor.  On the other hand, in all of Examples 2-1 to 2-30 using the  resin (P) containing the repeating unit represented by formula  (1) and the repeating unit represented by formula (A), the  resolution of an isolated line pattern was excellent, the PEB  temperature dependency was low, the pattern profile was  rectangular, and the sensitivity and etching resistance were  high.  [Examples 3-1 to 3-30 and Comparative Examples 3-1 to 3-4;  Extreme-ultraviolet Ray (EUV) Exposure, Organic Solvent  Development, Evaluation of Isolated Line]  (5) Preparation and Coating of Coating Solution of Actinic  Ray-Sensitive or Radiation-Sensitive Resin Composition  A coating solution composition having a solid content  concentration of 1.5 mass  % according to the formulation  shown in Table 5 below was microfiltered through a mem› brane filter having a pore size of0.05 µm  to obtain an actinic  ray-sensitive or radiation-sensitive resin composition (resist  composition) solution.  This actinic ray-sensitive or radiation-sensitive resin com› position was coated on a 6-inch Si wafer previously subjected  to a hexamethyldisilazane (HMDS) treatment, by using a spin  coater, Mark 8, manufactured by Tokyo Electron Ltd. and  dried on a hot plate at 100°  C. for 60 seconds to obtain a resist  film having a thickness of 50 nm.  The resist film-coated wafer obtained in (5) above was  patternwise exposed by using an EUV exposure apparatus  (Micro Exposure Tool, manufactured by Exitech, NA: 0.3,  X-dipole, outer sigma: 0.68, inner sigma: 0.36) through an  exposure mask (line/space=5/1). After the irradiation, the  resist film was heated on a hot plate at 100°  C. for 90 seconds,  then developed by puddling the organic developer shown in  Table 5 below for 30 seconds, rinsed by using the rinsing  solution shown in the Table below, spun at a rotation speed of  4,000 rpm for 30 seconds and baked at 95°  C. for 60 seconds  to obtain a resist pattern ofa 1: I line-and-space pattern having  a line width of 50 nm.  (6) EUV Exposure and Organic Solvent Development  (7) Evaluation of Resist Pattern  Using a scanning electron microscope (S-9380II, manu› facture by Hitachi Ltd.), the obtained resist pattern was evalu› ated for sensitivity, pattern profile, resolution in isolated line  pattern, PEB temperature dependency and etching resistance  by the following methods.  The irradiation energy below which the pattern of line/  space= 1: 1 with a line width of 50 nm cannot be resolved was  taken as the sensitivity (Eop ). A smaller value indicates  higher performance.  The cross-sectional profile of the  1:  1 line-and-space pat› tern with a line width of 50 nm formed at the irradiation dose  giving the above-described sensitivity was observed using a  scanning electron microscope and evaluated on a scale of  three grades of rectangular, tapered and reverse tapered.  The limiting resolution (the minimum line width below  which a line and a space cannot be separated and resolved) of  an isolated line pattern (line/space= 1: 5) formed at Eop above  was determined. This value was taken as "resolution (nm)". A  smaller value indicates higher performance.  The exposure dose for reproducing a line-and-space 1/1  mask pattern with a mask size of 50 nm when post-baking was  performed at 100°  C. for 90 seconds, was taken as an optimal  exposure dose. After performing exposure at the optimal  exposure dose, post-baking was performed at two tempera› tures of +2°  C. and -2°  C. with respect to the post-baking  temperature (that is, 102°  C. and 98°  C.), and respective  line-and-space patterns obtained were measured for the  length to determine the line widths L$_{1 }$ and L$_{2}$ .  The PEB  temperature dependency was defined as the fluctuation ofline  width per PEB temperature change of 1 °  C. and calculated  according to the following formula.  A smaller value indicates less change in performance due  to temperature change and is better.  A resist film having a thickness of 200 nm was formed on  a wafer and then subjected to plasma etching under the con› dition of a temperature of 23 °  C. over 30 seconds by using a  mixed gas of C$_{4}$F $_{6 }$ (20 mL/min) and  0 2  (  40 mL/min). There› after, the residual film amount was determined, and the etch› ing rate was calculated. The etching resistance was evaluated  based on the following criteria.  A: When the etching rate is less than 15 A/sec.  B: When the etching rate is 15 A/sec or more.  (7 -1) Sensitivity  (7-2) Evaluation of Pattern Profile  (7-3) Resolution in Isolated Line Pattern  (7-4) PEB Temperature Dependency  (7 -5) Etching Resistance  (Evaluation Criteria)  PEB Temperature dependency (nm/ 0  C.)~IL$_{1}$-L$_{2}$ 1/4  TABLES  Resist Composition  Photoacid  Resin  Hydro- Generator  Surfac- (mass%)  phobic  Solvent  (mass%)  Basic  tant  Developer  (mass  Resin  (mass  (mass  Compound  (0.01  (mass  Rinsing  ratio)  (mass%)  ratio)  ratio)  (mass%)  mass%)  ratio)  Solution  Example 3-1  P-1  S-1/S-2  z115  N-3  W-4  G-1  78  (80/20)  20  2  Example 3-2  P-2  S-1/S-2  z115  N-3  W-4  G-1  78  (80/20)  20  2  Example 3-3  P-3  S-1/S-2  z115  N-3  W-4  G-1  78  (80/20)  20  2  Example 3-4  P-4  S-1/S-2  z115  N-3  W-4  G-1  78  (80/20)  20  2 