Adhesion and Elastic Energy Analysis of Pattern Collapse in Surface-Modified FinFET Structures

Abstract In the semiconductor manufacturing process, the miniaturization of patterns has led to increased structural fragility, making pattern collapse a critical issue during the drying step in wet cleaning processes. Such collapse can lead to device defects, which must be avoided. One method to prevent pattern collapse is surface modification treatment (SMT), which substitutes hydrophilic surface OH groups with hydrophobic functional groups such as trimethylsilanol (TMS) groups. In this study, we modeled the FinFET structure of Si/SiO2 with TMS groups and investigated its behavior of the structures under the wet and dry conditions. The results revealed that collapse dynamics varied with the TMS coverage ratio, demonstrating the suppressive effect of SMT on collapse. Notably, focusing on the structural dynamics of the fins, we found that collapse occurs when the fins deform into a cantilever shape, highlighting a collapse mechanism distinct from the previously reported S-shaped beam deformation. In this paper, we discuss the collapse and recovery behavior by evaluating the adhesion energy and elastic energy of the fins. These findings provide valuable insights into the mechanisms of pattern collapse and offer potential strategies for enhancing semiconductor manufacturing processes.