Interaction of point defects with impurities in the Si-SiO_2 system and its influence on the properties of the interface

摘要

The results of investigations of the point defect generation, redistribution and interaction with impurities in the Si-SiO_2 system during the process of its formation by means of electron paramagnetic resonance (EPR) and nucleus magnetic resonance (NMR) techniques are presented. The type and density of the point defects that are generated in the Si surface layer during thermal oxidation depend on the oxidation condition: temperature, cooling rate, oxidation time, and impurity content. The interaction between the point defects with extended defects and impurities affects the properties of the Si-SiO_2 interface. The influence of the point defects may be diminished and the interface properties improved by an appropriate choice of the oxidation conditions. The difference between the interface properties of n- and p-type wafers may be connected with the different position of the Fermi level at the interface and different point defects density in the volume near the interface.