Search

Research was conducted to examine the generation of vacancy-related point defects in low dose 1.3 MeV proton irradiated high purity silicon. The objective was to attempt to explore the ionization effect to determine a migration energy for the silicon self-interstitial at room temperature and below. An experimental value for the migration energy of the silicon interstitial is obtained by the use of the inverse dose rate effect. Results suggest that the interstitial motion is strongly enhanced by ionization effects occurring during the irradiation.

Hafnium oxide films are deposited at room temperature on Si and 4H-SiC substrates, as well as on 4H-SiC p-i-n diodes. The analysis has shown that an introduction of a good quality Si[O.sub.2]/SiC interface prior to high-[kappa] dielectric passivation has reduced the density of interface states at the SiC surface and has in turn reduced the dominating component of the leakage current.

The self-assembled nanoporous alumina films were employed as masks for MeV ion track lithography. The fabrication method could be applied to a broad range of materials where irradiated volumes can be removed by chemical etching.

Crystallographic defects revealed by synchrotron white beam x-ray topography, electron beam induced current, optical microscopy, and electro luminescence are correlated with the electrical characteristics of medium voltage epitaxial 4H-silicon carbide diodes. These methods have shown the influence of screw dislocation defects on the lowering of the breakdown voltage of epitaxial silicon carbide p-n diodes while it is also shown that closed-core screw dislocations influence the formation and expansion of stacking faults.