Characterization of HfO_xN_y thin film formation by in-situ plasma enhanced atomic layer deposition using NH₃ and N₂ plasmas

Highlights: • Analysis of PE-ALD grown HfON thin films using NH₃ and N₂ plasmas. • PE-ALD grown HfON film showed high dielectric constant and thermal stability. • PE-ALD grown HfON film suppressed the interfacial layer. • High leakage current of HfON film was caused by bandgap lowing and band offset. - Abstract: The structural and electrical characteristics of in-situ nitrogen-incorporated plasma enhanced atomic layer deposition (PE-ALD) HfO_xN_y thin films using NH₃ and N₂ plasmas as reactants were comparatively studied. The HfO_xN_y test structures prepared using NH₃ and N₂ plasmas were analyzed by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and high resolution transmission electron microscopy (HR-TEM) to investigate the chemical composition, crystallinity, and cross-sectional layers including the interfacial layer, respectively. By utilizing NH₃ and N₂ plasmas, the nitrogen-incorporated HfO_xN_y thin films fabricated by in-situ PE-ALD showed a high dielectric constant and thermal stability, which suppresses the interfacial layer and increases the crystallization temperature. The high leakage current densities of the HfO_xN_y thin film test structures fabricated using NH₃ and N₂ plasmas caused by lowering the energy bandgap and band offset are related to the Hf−N bond ratio and dielectric constant