Theoretical analysis of the charge collection at a nano-Schottky contact

A theoretical analysis of the current collected in semiconductors in the electron beam induced current technique in the case of a nano-Schottky contact is given. The electron beam is in normal incidence and the surface recombination velocity is taken to be equal to zero. The analysis is based on the use of new boundary conditions imposed by the nano-scale size and shape of the electrode. Different expressions of the induced current are obtained from the diffusion equation as a function of polar coordinates, and their reliability are analyzed for the purpose of describing the induced current profiles which can be used for the determination of the minority carrier diffusion length. All expressions of the current depend on the nano-contact size, which has a great importance in the charge collection process, but not on nano-contact area.