Comparison study of mask error effects for various mask-making processes

Photomask is one of the most critical technologies for lithography. Optical lithography at resolution limit is a non- linear pattern transfer process. OPC (Optical Proximity Correction) technology has been used in the semiconductor industry for controlling the shape of pattern, and eliminating the line shortening and corner rounding effects for submicron feature. Therefore, OPC technology is an approach for improving lithography performance that has been received much attention recently. We investigated the lithographic performance in terms of EL (Exposure Latitude), DOF (Depth of Focus), and mask error effects for various mask fabrication. It was observed that mask error gave severe influence on the lithographic performance and the OPC simulation error also strongly depended upon the mask quality.