Absorption coefficient of metal-containing photoresists in the extreme ultraviolet
Absorption coefficient of metal-containing photoresists in the extreme ultraviolet
复制标题
含金属光刻胶对极紫外光的吸收系数
DOI：
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发表时间：
2018
期刊：
影响因子：
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通讯作者：
Y. Ekinci
中科院分区：
文献类型：
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作者：
R. Fallica;J. Haitjema;Lianjia Wu;S. Castellanos;A. Brouwer;Y. Ekinci
抽象的。光致抗蚀剂薄膜的吸收光量是光刻工艺中的一个关键参数，但其实验测量并不直观。利用同步辐射光测量了用于极紫外光刻的金属氧化物基光刻胶薄膜的光吸收。三种类型的材料进行了研究：锡笼分子，锆oxoclusters，和铪oxoclusters。含锡化合物被证明具有比传统的有机基光致抗蚀剂高三倍的光吸收。由于锆在EUV下的低吸收截面，锆氧簇的吸收率与有机聚合物基光致抗蚀剂的吸收率相当。含铪的抗蚀剂显示出约两倍于有机光致抗蚀剂的高吸收率，这是由于铪的显著更高的吸收率。从化学组成和晶体结构，确定旋涂膜的密度。使用薄膜的密度和表列数据的原子截面在EUV，这些抗蚀剂的预期吸收率进行了计算和讨论，与实验结果相比。测量的和预期的吸收之间的协议是相当好的，由于实际的膜密度的差异或由于旋涂的厚度不均匀性的一些实质性的差异。本文所开发的方法能够精确测量光刻胶的EUV吸收，并有助于EUV光刻胶的进一步开发和更精确的光刻建模。
Abstract. The amount of absorbed light in thin photoresist films is a key parameter in photolithographic processing, but its experimental measurement is not straightforward. The optical absorption of metal oxide-based thin photoresist films for extreme ultraviolet (EUV) lithography was measured using an established methodology based on synchrotron light. Three types of materials were investigated: tin cage molecules, zirconium oxoclusters, and hafnium oxoclusters. The tin-containing compound was demonstrated to have optical absorption up to three times higher than conventional organic-based photoresists have. The absorptivity of the zirconium oxocluster was comparable to that of organic polymer-based photoresists, owing to the low absorption cross section of zirconium at EUV. The hafnium-containing resist shows about twice as high absorptivity as an organic photoresist, owing to the significantly higher absorbance of hafnium. From the chemical composition and crystal structure, the density of the spin-coated films was determined. Using the density of the films and the tabulated data for atomic cross section at EUV, the expected absorptivity of these resists was calculated and discussed in comparison to the experimental results. The agreement between measured and expected absorption was fairly good with some substantial discrepancies due to differences in the actual film density or to thickness inhomogeneity due to the spin coating. The developed method here enables the accurate measurement of the EUV absorption of the photoresists and can contribute to the further development of EUV resists and more accurate lithographic modeling.