In-Situ And Real Time Stress Of 30.4 Nm Mo/Si Multilayer Mirror For The Moon-Based Euv Camera

Applications of Mo/Si multilayer mirrors for the moon-based extreme ultraviolet Camera (EUVC) require not only the minimal residual stress, but also little stress changes in the temperature environment on lunar surface. Hence, we deposit the 16.5 nm period Mo/Si multilayer mirror with a low as-deposited residual stress of -36 Mpa (compressive). The in-situ and real time stress tests are measured in the temperature cycling range from 20 degrees C to 130 degrees C. The results indicate that the stress gradually increases to the maximum of -100 MPa when heating up to 105 degrees C, then it gradually relaxes to 10 Mpa after thermal cycling to 130 degrees C. Such stress change has little influence on the performance of the Mo/Si multilayer mirror.