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Examples 2-1 to 2-20 and Comparative Examples 2-1 to 2-7 

Resist Patterning by ArF Lithography 1 

An antireflective coating solution (ARC-29A by Nissan Chemical Industries, Ltd.) was coated onto a silicon substrate and baked at 200° C. for 60 seconds to form an ARC film of 100 nm thick. The resist solution in Table 5 was spin coated onto the ARC and baked on a hot plate at 100° C. for 60 seconds to form a resist film of 90 nm thick. The resist film was exposed according to the ArF immersion lithography using an ArF excimer laser seamier (model NSR-S610C, Nikon Corp., NA 1.30, dipole illumination, Cr mask). The resist film was baked (PEB) at 80° C. for 60 seconds and developed in a 2.38 wt % tetramethylanm10nium hydroxide aqueous solution for 60 seconds. 

Evaluation Method 

The resist was evaluated by observing a 40-nm 1:1 line› and-space pattern under an electron microscope. The opti› mum dose (Eop) was a dose (mJ/cm 2 ) which provided a line width of 40 nm. The profile of a pattern at the optimum dose was compared and judged good or poor. 

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The width of lines of a 40-nm 1: 1 line-and-space pattern was measured under SEM to determine a line width variation (30 points measured, 3a value computed), which was reported as line width roughness (LWR). A smaller value of LWR indicates a line pattern with a less fluctuation and of better profile. In this test, the sample is rated good when LWR is equal to or less than3.0nmand poorwhenLWRis equal to or more than 3 .1 nm. 

Defects in the pattern as developed were inspected by a flaw detector KLA2800 (KLA-Tencor). A defect density ( count/cm 2 ) was computed by dividing the total number of detected defects by a detection area. The pattern formed was an iterated 40-nm 1: 1 line-and-space pattern. The defect inspection conditions included light source UV, inspected pixel size 0.28 µm, and cell-to-cell mode. In this test, the sample was rated good for a defect density of less than 0.05 defect/cm 2 and poor for a density of equal to or more than 0.05 defect/cm 2 . 

The collapse limit was a minimum width (nm) of lines which could be resolved without collapse when the line width was reduced by increasing the exposure dose. A smaller value indicates better collapse resistance. 

The test results of the resist compositions are shown in Table 6. 

