Effects of Substrate Temperature on the Leaning of Micropatterns during Rinse-Dry Process

Abstract

The spin drying, in which a rinsing liquid deposited on a wafer is rapidly dried by wafer spinning, is an essential step in semiconductor manufacturing process. While the liquid evaporates, its meniscus straddles neighboring submicron-size patterns. Then the capillary effects that pull the patterns together may lead to direct contact of the patterns, which is referred to as pattern leaning, a problem becoming more and more serious as the pattern size shrinks and the aspect ratio of the patterns increases. The interaction between elastic structures and capillary forces, orelasto-capillarity[1, 2], has long been observed in nature but just starts to find its applications in artificial system. It is particularly relevant to the fabrication of high-aspect-ratio structures in semiconductor manufacturing [3, 4, 5] because it is responsible for the stiction of patterns in rinsing and drying process. Here we visualize the micropattern leaning process and evaluate the role of substrate temperature in preventing collapse of patterns.