Dangling bonds on the Cl- and Br-terminated Si(100) surfaces

TL;DR

This study demonstrates the controlled desorption of individual halogen atoms from Si(100) surfaces using STM, and investigates the resulting silicon dangling bonds and their charge states, enabling local surface reactivity tuning.

Contribution

It introduces a method to selectively remove single halogen atoms from Si surfaces and analyzes the charge states of resulting dangling bonds with STM and DFT, providing new insights into surface reactivity control.

Findings

Successful desorption of individual halogen atoms using STM.

Identification of three charge states of silicon dangling bonds.

Potential to locally tune surface reactivity through charge state manipulation.

Abstract

Halogen monolayer on a silicon surface is attracting active attention for applications in electronic device fabrication with individual impurities. To create a halogen mask for the impurities incorporation, it is desirable to be able to remove a single halogen atom from the surface. We report the desorption of individual halogen atoms from the Si(100)-2x1-Cl and -Br surfaces in a scanning tunneling microscope (STM). Silicon dangling bonds (DBs) formed on the Si surface after halogen desorption were investigated using STM and the density functional theory. Three charge states: positive, neutral, and negative were identified. Our results show that the charge states of DBs can be manipulated, which will allow to locally tune the reactivity of the Cl- and Br-terminated Si(100) surfaces.