Impact of photoacid generator leaching on optics photocontamination in 193-nm immersion lithography
Impact of photoacid generator leaching on optics photocontamination in 193-nm immersion lithography
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DOI：
10.1117/1.2712841
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发表时间：
2007
影响因子：
2
通讯作者：
V. Liberman;M. Rothschild;S. Palmacci;A. Grenville
中科院分区：
文献类型：
--
作者：
V. Liberman;M. Rothschild;S. Palmacci;A. Grenville
抗蚀剂组分浸出到水中已经在几项研究中报道。即使光酸产生剂（PAG）的低溶解水平也可能导致投影透镜的最后光学表面的光污染。为了确定这种现象对光学器件寿命的影响，我们启动了一系列受控研究，将预定量的PAG引入纯水中，并对结果进行定量监测。这项研究确定了复杂的，非线性的路径导致光污染的光学。我们还发现，空间污染模式的光学强烈依赖于流动的几何形状。裸露的SiO2表面以及涂层CaF2光学进行了研究。我们发现，对于所有的表面，在典型的浓度浸出PAG，低于500 ppb，在原位自清洁过程中防止污染的光学。
Leaching of resist components into water has been reported in several studies. Even low dissolution levels of photoacid generator (PAG) may lead to photocontamination of the last optical surface of the projection lens. To determine the impact of this phenomenon on optics lifetime, we initiate a set of controlled studies, where predetermined amounts of PAG are introduced into pure water and the results monitored quantitatively. The study identifies the complex, nonlinear paths leading to photocontamination of the optics. We also discover that spatial contamination patterns of the optics are strongly dependent on the flow geometry. Both bare SiO2 surfaces as well as coated CaF2 optics are studied. We find that for all surfaces, at concentrations typical of leached PAG, below 500 ppb, the in situ self-cleaning processes prevent contamination of the optics.