Statistical analysis of shallow p-n junction leakage increase using XTEM results probabilities

The reverse current increase for CoSi2 silicided Si n(+)p shallow junctions is investigated, with particular interest for the diffusion component (I-d ), being the fundamental lower limit. The non-uniformity of the CoSi2 layer is shown to enhance I-d even without the presence of a catastrophic spikin g defect. The n(+) emitter thinning due to the Co reaction with Si enhances I-d by a reduction of the Gummel number. Here it is shown that, in additio n, local silicide thickness Variations cause a more than linear increase of I-d. A more general method for analysis of the physical variables (the ave rage junction depth x(j) and I-d) is shown, based on thickness statistical fluctuations, which are derived from cross-sectional transmission electron microscopy (XTEM) observations. It is applied for junctions with 50-200 nm mean depths. (C) 2001 Elsevier Science Ltd. All rights reserved.