Abstrakt
The integration of low-defect Ge layers on Si substrate is of in creas ing interest due to its possible ap plications in optoelectronics and CMOS tech nologies. To avoid nucleation of dislocations caused by relatively large lattice mismatch between Si and Ge, nanoheteroepitaxy strainrelieving mechanism was suggested.
To prove the functional ity of this mechanism, we investigate the strain field in Si line nanostructures covered by SiO2 growth mask with dimensions in order of 100 nm. By compar ison of exper i mental XRD data with simulations (X-ray kinematical scattering theory), we refined the shape coordinates of the nanostructures (i.e. coordinates of selected points from Si-pillar borderline, between which the border line can be interpolated by linear func tion with minor error) taken from TEM images.
We carried out a strain field simulation based on the elasticity theory and showed in sufficiency of conventional model of the strain in Si after thermal oxidation. Therefore we implemented an iterative evolutionary algorithm to de termine the strain field from the experimental XRD data.
Preliminary results, where we reached 1 order better agree ment, are shown