Papers by Author: Bo Cao

Abstract: The Cu thin films were deposited on P type Si (111) substrates by ionized cluster beam (ICB) technique. The surface properties and atomic binding energy of Cu thin films were studied by X-ray Photoelectron Spectroscopy (XPS). The results show that for all XPS spectra of Cu/SiO₂/Si (111) samples deposited by neutral cluster and ionized cluster beam (V_a=5 kV), the atomic binding energy of the films was no differences with bulk materials. The reason may be that the local energy deposition and atomic restructuring caused by surface treatment process resulting in the XPS spectra of the copper films was similar with bulk standard copper.

Abstract: The Cu thin films were prepared at room temperature by radio frequency magnetron sputtering on p-type Si (111) substrates. The surface morphology and interface reaction of Cu thin films were studied at different deposition condition by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results show that the existence of the native silicon oxide layer suppresses the interdiffusion and interface reaction of Cu and Si. The formation of the copper-silicide phase is observed by XRD when the annealing temperature arrives at 450 °C.

Abstract: The Cu thin films were deposited on P type Si (111) substrates by ionized cluster beam (ICB) technique. The surface morphology and roughness of Cu thin films were studied at different deposition condition by atomic force microscopy (AFM). The results show that the average grain size and surface roughness of the Cu thin films deposited at an acceleration voltage of 3 kV is smaller than other conditions.

Abstract: The Cu films were deposited on P type Si (111) substrates by ionized cluster beam (ICB) technique. The interface reaction and atomic diffusion of Cu/Si (111) system were studied at different annealing temperatures by X-ray diffraction (XRD) and Rutherford backscattering spectrometry (RBS). Some significant results were obtained: For the Cu/Si (111) samples prepared by ionized cluster beams at V_a=3 kV, the interdiffusion of Cu and Si atoms occurred in the as deposited samples. The RBS spectra features were changed with a very small extent with increasing the annealing temperature. There are no copper-silicide phases observed by XRD before and after being annealed at different temperatures. The reason may be that there is a thermally stable interface between Cu films and Si substrates formed.