Coexistence of Fast and Slow Luminescence in Three-dimensional Si/Si1-xGex Nanostructures

NRC publication: Ye

Photoluminescence and Raman scattering in Three-dimensional Si/Si1-xGex Nano-structures with Different Ge Content

NRC publication: Ye

Optical Properties of Composition-Controlled Three-dimensional Si/Si1-xGex Nanostructures

NRC publication: Ye

Optical Properties of Stranski-Krastanov Grown Three-Dimensional Si/Si(1-X)G(X) Nanostructures

NRC publication: Ye

High depth resolution Rutherford scattering using forward angles

Rutherford scattering of MeV 4He ions at forward angles has been used to determine the thickness and composition of single Si1 - xGex layers in Si. With scattering angles of about 20? the obtained depth resolution is up to 25% better than with standard RBS at glancing backward angles. The large scattering cross section at forward angles allows for the use of a small solid angle while maintaining good count rates and short acquisition times. Geometrical broadening of the energy spectra, due to the finite acceptance angle of the detector, is thus negligible. The kinematic factor is close to 1 for almost all elements in this geometry. Layers with different composition are therefore only distinguishable by the differences in spectrum height. The best accuracy for the stoichiometry is obtained by combining the measured energy loss in a layer with the areal density of the heavier element in that layer, which can be determined by standard RBS. The results are compared to RBS and X-ray diffraction measurements. The influence of multiple scattering is illustrated and a comparison to depth resolution calculations with the DEPTH code is made.NRC publication: Ye