Suppression of Acid Diffusion in Chemical Amplification Resists by Molecular Control of Base Matrix Polymers
Suppression of Acid Diffusion in Chemical Amplification Resists by Molecular Control of Base Matrix Polymers
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通过基础基质聚合物的分子控制抑制化学放大抗蚀剂中的酸扩散
DOI：
10.7567/jjap.34.6786
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发表时间：
1995
影响因子：
1.5
通讯作者：
S. Okazaki
中科院分区：
文献类型：
--
作者：
T. Yoshimura;H. Shiraishi;S. Okazaki
从基础基质聚合物的分子控制角度研究了化学增幅抗蚀剂曝光后烘烤（PEB）过程中酸扩散的抑制。制备了由基于甲酚酚醛清漆的基体聚合物、三聚氰胺树脂的酸催化交联剂和鎓盐的产酸剂组成的负型化学增幅抗蚀剂。基础基质聚合物的分子量分布通过沉淀法控制。用电子束在隔离线中对抗蚀剂进行曝光，以评估酸扩散特性。图案尺寸对 PEB 时间的依赖性清楚地表明，酸扩散根据菲克定律确定抗蚀剂图案尺寸。具有小多分散性的基础基质聚合物的抗蚀剂的扩散系数小于具有大多分散性的基础基质聚合物的抗蚀剂的扩散系数。通过应用具有小重均分子量和小多分散性的基础基质聚合物仍然可以抑制酸扩散。通过使用含有更多对甲酚成分的基础基质聚合物，可以进一步降低扩散系数。提出了一种基于由活性羟基基团和基础基质聚合物中的空位组成的酸扩散通道的扩散机制。
Suppression of acid diffusion during post-exposure baking (PEB) of chemical amplification resists is investigated from the standpoint of molecular control of base matrix polymers. Negative-type chemical amplification resists composed of cresol novolak-based matrix polymers, acid-catalyzed crosslinkers of melamine resins, and acid generators of onium salts are prepared. The molecular weight distributions of the base matrix polymers are controlled by means of a precipitation method. The resists are exposed with electron beams in isolated lines to evaluate the acid diffusion characteristics. Dependence of pattern sizes on the PEB time clearly shows that acid diffusion determines the resist pattern sizes based on Fick's law. The diffusion coefficients of resists with base matrix polymers with small polydispersities are smaller than those of resists with base matrix polymers with large polydispersities. Acid diffusion can still be suppressed by applying base matrix polymers with small weight-average molecular weights and small polydispersities. Diffusion coefficients can be further decreased by using base matrix polymers with more p-cresol components. A diffusion mechanism is proposed based on acid diffusion channels composed of active OH-groups and vacancies in the base matrix polymers.