200NM DEEP-UV LITHOGRAPHY USING STEP-AND-SCAN

This paper reports the performance of deep-UV resists on a new high-NA Step-and-Scan system. The study highlights the requirements for the p rinting of 200nm lithography using single-layer resists. Results are r eported for resist systems such as TOY APEX and ARCH2. SEM profiles ar e used to demonstrate key performance parameters of depth of focus and resolution for grouped and isolated line features. Data on linewidth control, measured at 195 points in a 26 x 32.5mm field using electrica l- probe technique, is presented. The effects of exposure level on lin ewidth control are measured. Linewidth linearity measurements for grou ped features and isolated features for the studied resist systems are used to assess the resolution capabilities of the resist systems. The measured performances of the resists are compared with resist simulati ons computed using PROLITH/2. The impact of resist properties on 200nm lithography is explored. Swing curves are measured for the resist sys tems on the high-NA, laser-illuminated Step-and-Scan system. The impor tance of quadrupole illumination in enhancing the depth of focus for g rouped features is discussed. The effect on pattern-feature linearity is measured. The enhancement of the depth of focus for both grouped an d isolated line features is analyzed. Quadrupole aperture design calcu lations are indicated.