Impact of Schottky contacts on forward and reverse saturation currents

Abstract

It has been found that the screening electric field E <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">l</sub> located at the periphery of the metal-semiconductor contact with Schottky barrier and penetrating to the contact, depends on contact diameter D and prevents electrons from direct motion, as well as strengthens the electric field of the contact. The impact of E <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">l</sub> on forward-bias regions of volt-ampere characteristic results in almost total absence of forward currents at low (U <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">f</sub> <;0.35 V) forward biases. At U <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">f</sub> >0.35 V the built-in electric field is compensated by the external electric field, while the volt-ampere characteristic curve takes its normal form. The impact of the built-in field on reverse-bias regions of voltampere characteristic results in significant effective decrease in height of a potential barrier by value φ* through reduction in its width near the vertex and significant increase in field electron emission. This results in significant (up to five orders of magnitude) increase in reverse saturation currents in relation to saturation currents.