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The grazing incidence X-ray reflectivity(GIXR) technique and atomic force microscopy(AFM) were exploited to obtain an accurate evaluation of the surfaces and interfaces for metalorganic chemical vapor deposition grown Al_xGa_(1-x)N/GaN superlattice structures.The X-ray diffraction results have been combined with reflectivity data to evaluate the layer thickness and Al mole fraction in the AlGaN layer.The presence of a smooth interface is responsible for the observation of intensity oscillation in GIXR,which is well correlated to step flow observation in AFM images of the surface.The structure with a low Al mole fraction(x = 0.25) and thin well width has a rather smooth surface for the R_(rms),of AFM data value is 0.45 nm.
The grazing incidence X-ray reflectivity (GIXR) technique and atomic force microscopy (AFM) were exploited to obtain an accurate evaluation of the surfaces and interfaces for metalorganic chemical vapor deposition grown Al x Ga 1-x N / GaN superlattice structures. X -ray diffraction results have been combined with reflectivity data to evaluate the layer thickness and Al mole fraction in the AlGaN layer. presence of a smooth interface is responsible for the observation of intensity oscillation in GIXR, which is well correlated to step flow observation in AFM images of the surface. The structure with a low Al mole fraction (x = 0.25) and thin well width has a rather smooth surface for the r_ (rms), of AFM data value is 0.45 nm.