Replicated mask surface roughness effects on EUV lithographic patterning and line edge roughness
Replicated mask surface roughness effects on EUV lithographic patterning and line edge roughness
复制标题
复制掩模表面粗糙度对 EUV 光刻图案和线边缘粗糙度的影响
DOI：
10.1117/12.881524
复制
发表时间：
2011
期刊：
影响因子：
--
通讯作者：
E. Anderson
中科院分区：
文献类型：
--
作者：
S. George;P. Naulleau;E. Gullikson;I. Mochi;F. Salmassi;K. Goldberg;E. Anderson
为了量化粗糙度对散斑的贡献，制造了具有不同粗糙度大小的多个区域的编程粗糙度基板。然后对基材进行多层涂覆。在多层沉积之前和之后收集原子力显微镜（AFM）表面图。还完成了波长反射率和总积分散射测量。基于角度分辨散射的功率谱密度直接与基于 AFM 的功率谱进行比较。我们表明，AFM 过度预测了皮米测量范围内的粗糙度。然后使用 SEMATECH 伯克利光化检查工具 (AIT) 对掩模进行波长成像，以直接表征航空图像散斑。建模用于测试不同测量方法在预测测量的航空图像散斑方面的有效性。 AIT 测量的对比度值比使用测量的均方根粗糙度输入获得的计算图像对比度值高 25% 或更高。各种计量方法可在多大程度上用于指定 EUV 掩模的容许粗糙度限制仍有待确定。进一步的建模和测量正在计划中。
To quantify the roughness contributions to speckle, a programmed roughness substrate was fabricated with a number of areas having different roughness magnitudes. The substrate was then multilayer coated. Atomic force microscopy (AFM) surface maps were collected before and after multilayer deposition. At-wavelength reflectance and total integrated scattering measurements were also completed. Angle resolved scattering based power spectral densities are directly compared to the AFM based power spectra. We show that AFM overpredicts the roughness in the picometer measurements range. The mask was then imaged at-wavelength for the direct characterization of the aerial image speckle using the SEMATECH Berkeley Actinic Inspection Tool (AIT). Modeling was used to test the effectiveness of the different metrologies in predicting the measured aerial-image speckle. AIT measured contrast values are 25% or more than the calculated image contrast values obtained using the measured rms roughness input. The extent to which the various metrologies can be utilized for specifying tolerable roughness limits on EUV masks is still to be determined. Further modeling and measurements are being planned.