Observation of electron excitation into silicon conduction band by slow-ion surface neutralization

TL;DR

This study reports the first experimental evidence of electron excitation into silicon's conduction band caused by slow-ion surface neutralization, revealing a new ion-induced internal electron emission process with potential applications.

Contribution

It provides the first experimental demonstration of ion-induced electron excitation into silicon conduction band via surface neutralization, expanding understanding of ion-silicon interactions.

Findings

Increase in reverse current observed in silicon photodiodes exposed to slow ions

Amplification of charge detected with avalanche photodiodes under high bias

Effect explained by Auger-type surface neutralization theory

Abstract

Bare reverse biased silicon photodiodes were exposed to 3eV He+, Ne+, Ar+, N2+, N+ and H2O+ ions. In all cases an increase of the reverse current through the diode was observed. This effect and its dependence on the ionization energy of the incident ions and on other factors are qualitatively explained in the framework of Auger-type surface neutralization theory. Amplification of the ion-induced charge was observed with an avalanche photodiode under high applied bias. The observed effect can be considered as ion-induced internal potential electron emission into the conduction band of silicon. To the best of our knowledge, no experimental evidence of such effect was previously reported. Possible applications are discussed.