The accurate determination of the effective order of absorption (EOA) for multiphoton absorption polymerization in radical photoresists is critical for the development and characterization of new materials with improved sensitivity and/or resolution. However, reliable measurement of the EOA is a challenging problem. The accuracy of four techniques that have been developed to address this issue is analyzed in terms of the known kinetics of the radical polymerization of polyfunctional monomers. It is demonstrated that methods that are based upon full reciprocity, i.e., the concept that the chemical response of the photoresist depends on the exposure dose, but not on the period over which this dose is delivered, only enable reliable determination of the EOA under a highly constrained set of circumstances. Methods that depend on limited reciprocity, i.e., the concept that the chemical response of the photoresist is the same when the total exposure window is constant, even if the details of the exposure within that window are varied, can enable accurate determination of the EOA over a considerably broader range of operating conditions. This prediction is verified experimentally. The analysis presented here provides guidance for future experiments and a basis for clearer interpretation of previously published results.

中文翻译：

---

确定自由基多光子光刻胶吸收有效阶数的方法：一种临界分析

准确确定自由基光刻胶中多光子吸收聚合的有效吸收阶数（EOA）对于开发和表征具有改进的灵敏度和/或分辨率的新材料至关重要。但是，可靠测量EOA是一个具有挑战性的问题。根据已知的多官能单体自由基聚合动力学，分析了为解决该问题而开发的四种技术的准确性。已证明基于完全互易性的方法（即，光致抗蚀剂的化学响应取决于曝光剂量，而不取决于该剂量的输送时间这一概念）只能在以下条件下可靠地确定EOA：高度受限的情况。依赖于有限互惠的方法，即 例如，即使总曝光窗口恒定，即使该窗口内的曝光细节发生变化，光致抗蚀剂的化学响应也相同的概念可以在相当宽的工作范围内准确确定EOA。条件。该预测已通过实验验证。本文介绍的分析为将来的实验提供了指导，并为更清晰地解释以前发表的结果提供了基础。