Structural change induced in LaAlO3 by ion implantation

Abstract

Ion implantation is used for various purposes in manufacturing semiconductor devices such as MOS‐FETs. In the present study, the effects of implantation of P+ or B+ ions on the structural change of single‐crystal LaAlO3 were examined. The optical absorption edge located at ∼5.6 eV, which seems to correspond to the bandgap energy of LaAlO3, is hardly affected by the ion implantation. The X‐ray diffraction peak intensity at 2θχ=23.5° is decreased by the ion implantation. The intensities of three sharp photoluminescence (PL) peaks detected at 1.62, 1.65, and 1.69 eV, which appear only when the samples are crystalline, become smaller by ion implantation. However, the intensity of a broad PL peak at ∼2.8 eV due to the oxygen vacancy, which is detectable in both amorphous and crystalline samples, hardly changes after the ion implantation. These results indicate that the ion implantation degrades the crystallinity of LaAlO3. © 2015 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.