Effects of Interfacial Strength and Dimension of Structures on Physical Cleaning Window

Abstract

Four different types of FINs; amorphous Si (a-Si), annealed a-Si, polycrystalline Si (poly-Si) and crystalline Si (c-Si) were used to investigate the effect of interfacial strength and the length of structures on the physical cleaning window by measuring their collapse forces by atomic force microscope (AFM). A transmission electron microscope (TEM) and a nanoneedle with a nanomanipulator in a scanning electron microscope (SEM) were employed in order to explain the different collapse behavior and their forces. Different fracture shapes and collapse forces of FINs could explain the influence of the interfacial strength on the pattern strength. Furthermore, the different lengths of a-Si FINs were prepared and their collapse forces were measured and the shorter length reduced their pattern strength. Strong adhesion at the interface resulted in a wider process window while smaller dimensions made the process window narrower.