Study of Er+ ion-implanted lithium niobate structure after an annealing procedure by RBS and RBS/channelling

Erbium-doped lithium niobate (Er:LiNbO3) is a prospective photonics component, operating at lambda = 1.5 mu m, which could be used as an optical amplifier or waveguide laser. We have focused on the structure of Er:LiNbO3 layers created by 330 key erbium ion implantation (fluences 1.0 x 10(15), 2.5 x 10(15) and 1.0 x 10(16) cm(-2) 1) in the X, Z and two various Y crystallographic cuts of LiNbO3. Five hours annealing at 350 degrees C was applied to recrystallize the as-implanted layer and to avoid clustering of Er. Depth distribution of implanted Er has been measured by Rutherford Backscattering Spectroscopy (RBS) using 2 MeV He ions. Defects distribution and structural changes have been described using the RBS/channelling method. Data obtained made it possible to reveal the relations between the crystallographic orientation of the implanted crystal and the behaviour during the restoration process. The deepest modified layer has been observed in the perpendicular Y cut, which also exhibits the lowest reconstruction after annealing. The shallowest depth of modification and good recovery after annealing were observed in the Z cut of LiNbO3. Since Er-depth profiles changed significantly in the perpendicular Y cut, we suppose that the crystal structure recovery inhibits Er mobility in the crystalline structure. (C) 2010 Elsevier B.V. All rights reserved.