Paper SS-TuP6
Reaction of Hydrazine with Cl-terminated Si(111) Surface

Tuesday, November 11, 2014, 6:30 pm, Room Hall D

This work focuses on obtaining well-defined surface of silicon functionalized with hydrazine to produce an oxygen-free platform for further functionalization. Single crystalline Si(111) surface has been prepared using modified RCA procedure to produce a well-defined H-terminated Si(111) surface. Next, Cl-terminated Si(111) surface is prepared from H-terminated Si(111) surface using PCl₅ in chlorobenzene solvent with trace amount of benzoyl peroxide as a reaction initiator under nitrogen atmosphere following previously established procedures. Hydrazine-functionalized Si(111) sample is obtained from Cl-Si (111) surface with anhydrous hydrazine at 35°C under Ar atmosphere. To confirm the presence of Si-N bonds following this procedure and to establish the structures of surface species produced, we followed the reaction by Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, and time-of-flight secondary ion mass spectrometry. To study the configuration of Si-NH_x groups on the surface, result was compared with the results of phenylhydrazine reactions on Cl-terminated silicon surface by wet chemistry method and also on clean silicon surface under ultrahigh vacuum (UHV) condition. Density functional theory (DFT) calculations were performed to infer the mechanisms of surface reactions and to compare the predicted vibrational spectra and core-level energies with the results of experimental studies.