Low-energy focused ion-beam system combined with molecular-beam epitaxy system for fabrication of 3D buried semiconductor structures

摘要

Abstract: Focused ion beam (FIB) system combined with molecular beam epitaxy is of potential importance for fabricating 3D buried semiconductor structures. However, reduction of ion irradiation induced damage, as well as small ion beam diameter, is needed. Low energy FIB system can produce focused beams with a landing energy less than 100 eV by retarding from an accelerating energy of 15 - 25 keV. From the optics simulation performed by Munro code, the beam diameter was estimated to be about 100 nm at a landing energy of 100 eV and a beam current of 60 pA, for an ion source with a current density of 20 $mu@A/sr and an energy spread of 10 eV. In this paper, the characteristics of our low energy FIB system, especially for the beam diameter, was discussed and compared with the calculated result. Direct deposition of Au film by low energy FIB was performed as an example using low energy FIB process and investigated the purity of the deposited film.!6