热处理Co/C软X射线多层膜的掠入射反射率增强

研究了低温退火Co/C软X射线多层膜中掠入射反射率的增强现象．通过测量一级调制峰强度随退火温度和时间的变化，测得了低至-10^-25m²s^－1的有效扩散系数．由于所研究的Co/C多层膜的调制波长远大于Co-C系统的扩散临界波长，有效扩散系数近似等于真实宏观扩散系数．负的宏观扩散系数表明，在Co-C系统中有相分离的趋势．这一结果可解释为由Miedema宏观原子模型计算得到的正的Co-C系统的混合焓．高退火温度下反射率的降低是界面锐化与界面粗糙化 关键词：

ENHANCEMENT OF THE REFLECTIVITY OF Co/C SOFT X-RAY MULTILAYERS AT GRAZING INCIDENCE BY THERMAL TREATMENT

We report a significant increase of the reflectivity of a soft X-ray Co/C multilayer at grazing incidence after low temperature annealing. By monitoring the enhancement of the first order modulation peak on annealing, the effective interdiffusion coefficient as low as -10^－25ｍ²ｓ^－1 has been measured,which is nearly equal to the true macroscopic interdiffusion coefficient as the modulation wavelength of the Co/C multilayer studied is well above the critical wavelength. The negative true macroscopic interdiffusion coefficient indicates that there is a tendency to phase separation in the Co-C system, which can be interpreted as the positive enthalpy of mixing calculated based on Miedema′s macroscopic atom model. The decrease of reflectivity above some anneal temperature is also discussed and explained as the competition between interfacial sharpness and roughness.