Study Of ArF Immersion Lithography And Development Of Optical Lithography Simulator

ArF immersion lithography has been considered as a promising method for 65nm node by a factor of refractive index n of the liquid filled into the space between the bottom lens and wafer. A systematic study on ArF immersion lithography is firstly presented by focusing on the optical system, mask, stage synchronization error. What's more, the first optical lithography simulator named MicroCruiser have been developed successfully in China and got the copyright protection from Chinese government.At First, impact of numerical aperture and partial coherence on DOF is demonstrated under various illumination and mask conditions. As a result, the eligible optical parameters are found for better lithography performance. The explanation for the peak value of DOF is given through three beam imaging process , MicroCruiser 2.0, Prolith version 8.0.2 and k₂ factor based on the Rayleigh equation. Then, Full Field Analysis of pattern displacement by lens aberration in ArF immersion lithography is demonstrated. It is shown that the crosstalk between different Zernike coefficients is more essential than a merely RMS value for the impact of aberration onimaging.Secondly, impact of mask errors and synchronization error on lithography performance is studied under different illuminations through CD uniformity. Great focus is put on the mask bias for binary mask, phase and transmittance error for the phase-shifting mask. The research point out that when MSD is less than 6nm, to make the CD error is below 10%, mask bias , transmittance error and phase error should be...