Impact of transmission error for attenuated phase shift mask for 0.10 um Technology

Abstract

Resolution enhancement techniques (RET) have been widely used to extend existing lithography to print features below the wavelength of the light source. One of such techniques is phase shifting. Due to the relative ease of implementation, the application of attenuated phase shift mask (PSM) is relatively more common compare to the strong alternating phase shift mask. The impact of the mask error critical dimension (CD) and its effect on printing onto wafers have widely been studied. However, the transmission error incurred in the blank and mask making has not been popularly investigated. This paper will study the impact of transmission error on the CD of wafer printing level. Simulation studies have be preformed for isolated lines as well as dense lines with assist features using 248 nm laser source. In addition, the effect of phase error by on-axis as well as annular illumination type of light source will also be investigated.