Non-contact Atomic Force Microscopy Simulations of Hydrogen-terminated Si(100) Surfaces with a Methyl

Abstract

Toward the development of a simulator of scanning probe microscope for systems with adsorbed organic molecules, we simulate non-contact atomic force microscope images of hydrogen-terminated Si(001)2×1 surfaces with an isolated methyl using a Si tip with and without a hydrogen atom at the apex, using a density-functional based tight-binding method. We examine the constant height, constant frequency and energy dissipation images. In addition to normal images of constant height and constant frequency modes, we obtain the exotic energy dissipation images, where a low dissipation spot is surrounded by a ring of high dissipation region. These images can be understood from the site-dependence of force hysteresis.