|
We explore technical and practical issues to apply EAPSM technology with high transmission into ArF lithography. This technique needs to be reviewed in the standpoint of process and device fabrication using short wavelength, high NA, OAI and OPC technology. In this paper, we analyze optical characteristics of multi-stacked film that composed of phase material like MoSi, Cr-SiON, Cr-SiO2, and Ta-SiO2. Three-dimensional analyses of film structure are to consider intensity variations and optical influence by n &k value, thickness and polarization light. The comparison will be focused on optimization or determination of each high T materials. Moreover, we specify CD impacts of mask CD error, variations of phase and transmission for various pattern size, and 3D structure. Polarization effect in this structure and high NA condition will be also interesting part to be studied impacts on process.
In the device application of technology, we consider overall process margin to satisfy cell & periphery design rule and OPC treatment to improve process windows. Optimum SRAF design and tri-tone mask technology will be key issue to improve DOF margin of specific design rule in OPC treatment. For 65nm technology or less, intensity formation distributed on mask affects CD and process margin directly on wafer patterning process. High transmission EAPSM will have specifically differences with 6% EAPSM in OPC treatment and it will be required new OPC rule in ArF lithography. Using simulation and experiment, we find high transmission EAPSM has advantages in device manufacturing and approach technical issue to be solved in material, process and device application. This technique shows to improve exposure latitude & DOF margin, and to reduce MEEF in process. Finally it will be good candidate to satisfy lithography requirement of 65nm and 45nm node.
|
