Collapse behavior of KrF resist line pattern analyzed with atomic force microscope tip

In recent years, micro fabrication technique has become important to realize electronic micro devices such as high density memory and liquid crystal display. Particularly, a positive working photoresist is regarded as an important mask material for dry or wet etching processes. As increasing the integration density of memory device, an improvement of adhesion strength of micro resist pattern has been recognized as one of important problem because its aspect ratio becomes higher. In these days, various studies on adhesion phenomena of photoresist material have been accomplished. A great deal of effort has been made on monitoring the adhesion property. What seems to be lacking, however, is quantitative and direct analysis. However, with the invention of the atomic force microscope (AFM), we have been equipped in good time with the appropriate tools to understand the physical properties of condensed matter on a nanometer scale. In this regard, present author has already proposed the novel principle of direct analysis method for resist micro pattern, that is, direct peeling with the AFM tip (DPAT). The purpose of this paper is to analyze the collapse property of fine line pattern on the point of residue formation.