Defect Reduction in ArF Immersion Lithography Using Particle Trap Wafers With CVD Thin Films

Particle trap wafers were applied to ArF immersion lithography to reduce the immersion-related defectivity. Interfacial free energy (gamma
_A-particle
) and work of adhesion (W
_A-particle
) between particle trap wafers and particles in immersion water explain the potential of trapping particles by the particle trap wafers. It was found that the treated SiCN chemical vapor deposition wafer performed well as a particle trap wafer and can help defect reduction in immersion lithography.