FIB prepared and Tripod polished prepared p-n junction specimens examined by off-axis electron holography

Abstract

Off axis electron holography is a TEM-based technique which allows the amplitude and phase information that are carried in electrons that have passed through a specimen to be recovered. This is achieved by using an electron biprism that creates two virtual sources in the back focal plane which act to form an interference pattern, or hologram in the image plane. In the absence of magnetic fields, the phase shift of an electron as it passes through a specimen in the direction z is given by

$$ \phi (x,y) = C_E \int\limits_{sample} {V(x,y,z)d(z),} $$

(1)

where C _E is a constant depending on the energy of the electron beam, ϕ is the change in phase, and V is the potential of the specimen along the beam path [1].