Surface Roughening and Microstructure of Tantalum Nitride Films Sputtered at Different N_2/Ar Flow Ratios

摘要

Tantalum nitride (Ta-N) films with different thicknesses varying from 50 nm to 1000 nm were deposited on Si(111) substrates by reactive magnetron sputtering as a function of N_2/Ar flow ratio. Microstructure and surface morphology were investigated by using X-ray diffraction (XRD) and atomic force microscopy (AFM), respectively. With increasing NVAr flow ratio, the film structures undergo a gradual transition from polycrystalline structure to amorphous along with the changes of phase composition. Film surface roughness R_(rms) first increases and then decreases.