How Nanocavities in Amorphous Si Shrink Under Ion Beam Irradiation: An in situ Study

Abstract

Nanocavities were formed in Si substrates by conventional H implantation and thermal annealing, after which the samples were amorphized by Si ion irradiation. The size evolution of the nanocavities was monitored in situ during further ion irradiation with Si or As at temperatures of 300 or 600 K. The decrease in nanocavity diameter during ion irradiation depended linearly on the ion fluence. The rate of shrinkage differed according to the ion beam-induced atomic displacement rate and had little or no temperature dependence. These in situ results shed new light on possible ion-beam-induced nanocavity shrinkage mechanisms.