Extraction of diffusion length using junction-less EBIC

Abstract

The electron-beam-induced current (EBIC) mode

of the scanning electron microscope (SEM) has been widely used

in semiconductor materials and devices characterization in

particular the extraction of minority carrier properties. The

conventional approaches require the sample to have a built-in

electric field created by the charge collecting junction that

separates the majority carriers from the minority carriers and

drives the induced current into the external circuitry for

detection. As a result, these conventional approaches are not

applicable for samples without junctions, i.e. bare substrates.

This paper discusses the feasibility of extracting the minority

carrier diffusion length in junction-less sample using the

junction-less EBIC technique with the use of a two-point probe

method. A 2-D device simulator is used to verify this technique

and it is found the accuracy depends on the location of the origin.