title: Selective ion-induced intermixing and damage in low-dimensional GaN/AlN quantum structures.
abstract: Ion-induced intermixing and damage is evaluated in GaN/AlN superlattices of quantum dots (QDs) and quantum wells (QWs) using 100 keV Ar(+) implantation at low temperature (15 K). Despite the similar damage build up at low fluences, a significant increase of the damage accumulation takes place for QDs at high fluences. Elemental depth profiles were fitted with a diffusion model, revealing the higher intermixing efficiency in QD superlattices, significantly higher than for QWs. The scaling of diffusion length with the local fluence and defect concentration is understood on the basis of cascade mixing and migration of defects in the cation sublattice. The selective intermixing/damage of QDs is explained by the promotion of lateral diffusion mechanisms that result in smooth interfaces, as well as by an enhanced diffusivity due to the characteristic strain distribution in QD superlattices.
authors.affiliation: Instituto Superior Técnico, Campus Tecnológico e Nuclear, Universidade de Lisboa, 2695-066 Bobadela LRS, Portugal.
authors.forename: A
authors.initials: A
authors.lastname: Redondo-Cubero
authors.forename: K
authors.initials: K
authors.lastname: Lorenz
authors.forename: E
authors.initials: E
authors.lastname: Wendler
authors.forename: D
authors.initials: D
authors.lastname: Carvalho
authors.forename: T
authors.initials: T
authors.lastname: Ben
authors.forename: F M
authors.initials: FM
authors.lastname: Morales
authors.forename: R
authors.initials: R
authors.lastname: García
authors.forename: V
authors.initials: V
authors.lastname: Fellmann
authors.forename: B
authors.initials: B
authors.lastname: Daudin