摘要:

Outgassing rates of aluminium samples coated with Al, Fe, and B were studied as a function of the surface composition at and near room temperature. The surface was changed by diffusion processes caused by heating in argon at atmospheric pressure and in vacuum. Achieved effects of these preparations were studied by x-ray photoelectron spectroscopy depth profiling, scanning electron microscopy, and atomic force microscopy measurements. It can be shown that the outgassing rate is independent on the atomic concentration of O, C, Al, Fe, and B in the nanometer range for many105 s,when the samples were prepared in this way. The samples coated and heated at 500 °C in vacuum and the aluminum surface cleaned with ethanol have nearly the same outgassing behavior after air exposure. Therefore it can be concluded that the short time outgassing is only controlled by contamination and desorption.

ISSN:0734-2101    

DOI:10.1116/1.581000

出版商:American Vacuum Society    

年代:1998

数据来源: AIP

摘要:

Ion channeling analysis and x-ray diffraction reciprocal space maps have been performed onInxGa1−xAsbuffer layers grown with different composition profiles on well-cut (001) GaAs substrates. On all of the samples analyzed we detect acurvatureof the layer lattice, i.e., a tilt of the lattice with respect to the substrate which varies coherently along the sample surface. The layer tilt is directed inward defining a curvature that is concave, large (up to2.5° cm−1) and that decreases when approaching the substrate. We describe this new phenomenon in terms of a coherent lateral distribution of the orientations of the misfit dislocation Burgers’ vectors.

ISSN:0734-2101    

DOI:10.1116/1.581001

出版商:American Vacuum Society    

年代:1998

数据来源: AIP

ISSN:0734-2101    

DOI:10.1116/1.581002

出版商:American Vacuum Society    

年代:1998

数据来源: AIP