Evaluation Method of "Formablity" in Nano/Micro Processing and Its Application to Inprint Lithography

提出了独立于现有成形方法的“成形性”概念，它代表成形的基本可能性。这一概念可以用来评估开发一种新的成形技术以生产新产品的努力有多大的实际可能性。在这项研究中，我们已经开发了一种方法的定性和定量评估的“可成形性”在纳米/微米加工，我们已经将其应用到压印光刻，预计将成为新的形成方法之一，在下一代。应用表明，该方法的理论可行性和局限性如下：（1）压印光刻中的“成形性”包括脱模性和转印性。根据分离开始的界面，将脱模性半定量地分为三个级别：模具/树脂之间的分离、树脂/树脂之间的分离和树脂/基体之间的分离。脱模性的基本因素是树脂模具与基体树脂的结合能之比和要形成的形状的纵横比。定量地说，当树脂-模具与基础树脂的内聚能之比小于或等于1时，脱模是可能的。但是，在大的长径比情况下，为了获得良好的脱模性，应降低内聚能的比率，因为该比率与长径比成反比。（2）根据脱模后树脂的变形程度，将转移性半定量地分为三个等级。该转印性取决于能量比（B/A）和纵横比（E/D），其中“A”是树脂的内聚能，“B”是树脂和模具之间的内聚能，并且（E/D）是要形成的形状的纵横比。转移性好的定量条件是（E/D）[≤]-4×（B/A）+3，而（E/D）[≥]-4×（B/A）+4时，不能从模具转移到树脂。

An idea of "formability" which stands for fundamental possibility of forming and is independent of existing forming methods has been proposed. This idea can be used to evaluate how much the effort to develop a new forming technique for producing new products has practical possibility. In this study, we have developed a method of qualitative and quantitative evaluation of the "formability" in nano/micro processing and we have applied it to inprint lithography that is expected to be one of the new forming methods in the next generation. The application has clarified theoretical possibility and limits of the new method as follows :(1)"Formability" in inprint lithography consists of mold releasability and transferability. Mold releasability is, semi-quantitatively, classified into three levels depending on interfaces where separation begins : separation between mold/resin, separation between resin/resin and separation between resin/base. The basic factors for mold releasability are the ratio of cohesive energy of resin-mold to base-resin and the aspect ratio of a shape to be formed. Quantitatively, mold release is possible when the ratio of cohesive energy of resin-mold to base-resin is less than or equal to 1. However, in case of large aspect ratio, the ratio of cohesive energy should be decreased for condition of good mold release, because the ratio is in inverse proportion to the aspect ratio.(2)Transferability is, semi-quantitatively, classified into three levels based on the degree of deformation of resin after mold release. This transferability depends on the energy ratio (B/A) and the aspect ratio (E/D), where 'A' is cohesive energy of resin, 'B' is cohesive energy between resin and mold, and (E/D) is the aspect ratio of a shape to be formed. Quantitative condition for good transferability is(E/D)【less than or equal】-4×(B/A)+3,while for(E/D)【greater than or equal】-4×(B/A)+4,transfer from mold to resin is impossible.