Static test evaluation of EUV1 full-field exposure tools - (PPT)

摘要

We present first results from Nikon's new low aberration, low flare optic installed at the Kumagaya (Japan) full-field EUV1 tool. A unique feature of this full-field tool is variable illumination coherence. Two illumination conditions are studied (σ= 0.5 and 0.8). This tool uses a Xe-based DPP source from Xtreme Technologies. The source power at IF is 3.3W Out-of-band radiation is well below 5% at the wafer planev The projection optic has an average WFE of 0.4nm rms (min 0.3 to max 0.5 nm rms) and center-field flare is calculated to be 7.3% [to be published in 2009]. Measured flare closely compares with calculated flare. At the center of the slit, measured flare ranges from 7.5% to 8.5%. A full through-slit flare map is presented. Tool TFD in static mode is approximately 100nm. Both sigma of 0.5 and 0.8 bright-field line (BF) patterning is shown with ultimate resolution of 26nm half-pitch. CDU, LWR, cross-slit H/V bias, DoF, EL%, MEEF, pitch-coherence, measured coma and astigmatism are evaluated for BF patterns for both sigma conditions and equivalent data for DF trenches for sigma of 0.5 only. Additionally, the imaging performance of 2D line and trench patterns is explored. During the evaluation a deliberate source cathode change was performed and we report the impact on patterning performance.