A group of several methods for detailed investigation of electrically active defects and their properties in insulator-semiconductor (IS) and metal-insulator-semiconductor (MIS) structures was developed. It consists of different ways of analyzing electrically active defects including precision measurements of local electrophysical properties of Si structures, mapping of defects in Si structures by means of nematic liquid crystals (NLC), application of scanning electron microscopy (SEM) in electron beam induced current (EBIC) mode for localization of electrically active defects in the semiconductor of MIS structures. Local electrophysical measurements were carried out by using dynamic unsteady-state current¯voltage characteristics (DUCVC) and their modifications which have higher sensitivity to detection of generation processes in MIS structures as compared with ordinary capacitance¯voltage characteristics. Depth distributions of bulk

generation lifetime of minority carriers in semiconductors, obtained by the DUCVC method, reflect normalized electrically active defects profiles near the was interface. The NLC method was nondestructive and makes possible to analyze lateral distribution of defects with high local conductivity in insulating films. It was shown that in the case of thin SiO2 films on Si electrically active defects at semiconductor surface were also revealed by the NLC method. As a result determination of electrically active defects coordinates opens possibility for further detailed investigation of separate electrically active defects properties by the DUCVC method using local Hg probe 5μm in size. Special MIS gated p¯n junctions were used for mapping of electrically active defects with high recombination velocity in semiconductor under the metal or polysilicon gates. Combination of the described methods was applied for investigation of local electrically active defects properties of Si-based structures, which were used for fabrication of integrated circuits. The influence of gettering on electrically active defects concentration in Si and SiO2 was investigated.

Investigation of Electrically Active Defects in Si-Based Semiconductor Structures. V.M.Popov, A.S.Klimenko, A.P.Pokanevich: Materials Science and Engineering B, 2002, 91-92, 248-52