Dissolution Inhibition in Positive Novolak Resists

正诺伏拉克抗蚀剂是当今半导体技术中最重要的图案化系统，但其作用机理尚不清楚。本研究提出了一种抗蚀性能的机理模型，如果得到验证和完善，将为这些重要材料的进一步技术开发提供合理的依据。最近的研究表明，酚醛树脂在碱水中的溶解受碱基向固体聚合物中扩散的速度控制。现在认为，电解液向酚醛树脂中的扩散遵循由亲水中心即树脂的OH-基团定义的路径，并避开了基质的疏水区域。溶解抑制剂通过阻断这些亲水性扩散通道发挥作用。建议通过设计不同酚类浓度的树脂来验证亲水扩散路径的概念，从而改变亲水位置的分离并监测位置稀释对溶解速度的影响。

Positive novolak resists are by far the most important patterning systems of today's semiconductor technology, yet their functional mechanism is not well understood. This research deals with a mechanistic model of resist function, which if validated and completed would provide a rational basis for the further technical development of these important materials. It was recently shown that novolak dissolution in aqueous alkali is controlled by the rate of diffusion of the base into the solid polymer. It is now suggested that diffusion of the electrolyte into novolak follows a path defined by hydrophilic centers i.e. the OH-groups of the resin, and avoids the hydrophobic regions of the matrix. Dissolution inhibitors function by interrupting these hydrophilic diffusion channels. It is proposed to validate the concept of hydrophilic diffusion pathways by designing resins with a varying concentration of phenols and in this way vary the separation of hydrophilic sites and monitor the effect of site dilution on dissolution rate.