Gas phase chlorination of hydrogen-passivated silicon surfaces

A simple method is described to functionalize hydrogen-passivated Si(111) and Si(100) surfaces with chlorine (Cl2) gas. Infrared-absorption spectroscopy provides a positive identification of chlorination and mechanistic information on the chlorination of H-terminated Si surfaces, and on the structure and stability of chlorine-terminated Si surfaces (Cl∕Si). We find that the chlorination process does not change the surface morphology: H∕Si(111)-(1×1) surfaces and HF-etched Si(100) surfaces remain atomically flat and atomically rough, respectively, upon chlorination. Chlorinated S: surfaces are stable in a nitrogen atmosphere for over 12 hours.