200nm Deep-UV lithography using Step-and-Scan

Abstract

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 printing of 200nm lithography using single-layer resists. Results are reported for resist systems such as TOK, APEX and ARCH2. SEM profiles are 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 × 32.5mm field using electrical- probe technique, is presented. The effects of exposure level on linewidth control are measured. Linewidth linearity measurements for grouped 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 simulations computed using PROLITH/2. The impact of resist properties on 200nm lithography is explored. Swing curves are measured for the resist systems on the high-NA, laser-illuminated Step-and-Scan system.The importance of quadrupole illumination in enhancing the depth of focus for grouped features is discussed. The effect on pattern-feature linearity is measured. The enhancement of the depth of focus for both grouped and isolated line features is analyzed. Quadrupole aperture design calculations are indicated.