Effect of the dissolution contrast on process margins in 193-nm lithography

摘要

We examine the process margins of chemically amplified ArF resists designed for the single layer process. We measured the dissolution characteristics and investigated how the dissolution contrast affected the lithographic performance. We confirmed that high dissolution contrast can improve both the resolution and process margin. A 0.13 $mu@m line and space pattern can be obtained. However, the depth of focus is not good enough for device fabrication. To achieve an acceptable process margin, we applied resolution enhancement techniques to the high-contrast resist. Applying off-axis illumination and an attenuated phase-shifting mask can greatly improve the process margin. 1.2 $mu@m and 0.8 $mu@m defocus margins were obtained at 0.15 and 0.13 $mu@m line and space patterns, respectively.