| 摘要 |
A Wynn-Dyson imaging system with reduced thermal distortion is disclosed, wherein the reticle and wafer prisms are made of glass material having a coefficient of thermal expansion of no greater than about 100 ppb/°C. The system also includes a first IR-blocking window disposed between the reticle and the reticle prism, and a second matching window disposed between the wafer and the wafer prism to maintain imaging symmetry. The IR-blocking window substantially blocks convective and radiative heat from reaching the reticle prism, thereby reducing the amount of thermally induced image distortion in the reticle image formed on the wafer. |
