Characterization of Electrically Active Defects in Si Using CCD Image Sensors

Abstract : The correlations that could be made between dark current spikes and defects observable in transmission electron microscopy have been statistical so far. That is, the number of visible defects of a type observable in the electron microscope is correlated with the number of dark current spikes observable in the region of the imager from which the sample was taken. this is an adequate technique when 1% or more of the pixels contain dark current spikes. This approach has enabled us to look at a larger number of specimens for each material, and therefore to obtain a better idea of the total defect picture in the material. In the coming quarter we plan to attempt some one-to-one correlations between the video image and transmission electron micrographs for microscopic (less than 1 micrometer) defects. Section II of this report presents the result of experiments for each group of materials that is being used. Also included in Section II are observations on the effectiveness of ISS backside damage, the relationship between total dark current and dark current spike density, and a discussion of the absence of any effects from transition metal impurities. The final section of this report discusses the origin of these defects and what may be done to eliminate them.