Growth of thin zirconium oxide films on the 6H-SiC(0 001) surface

摘要

This is the first work which presents results of the growth of Zr on the SiC(0001) surface in the presence of oxygen by using X-ray photoelectron spectroscopy (XPS), low energy electron diffraction (LEED), and scanning tunneling microscopy (STM). The growth of ZrO_2 films, STM monitored, proceeded up to a thickness of 8 ML zirconium almost in layer-by-layer mode with some irregular islands. Some paths with a changed conductance, indicating its mixed diode- and ohmic type, were also observed. After submonolayer Zr depostion and annealing the sample at 600 ℃, the 1 × 1 structure appeared indicating that the first layer grows according substrate structure and forms hexagonal zirconium. Further annealing at 1000℃ and above revealed a doubled structure identified as a one stemmed from the SiC substrate and Zr adsorbate. Additionally, a new p(2 × 2) structure arose which is interpreted as an alternate zirconium layer. Confirmation of this thesis is found in XPS studies.