Formation and Annealing Behavior of an Amorphous Layer Induced by Tin Implantation Into Sapphire

• Published in: Surface & coatings technology Vol. 51; no. 1-3; pp. 415 - 419
• Main Authors: Romana, L J, Sklad, P S, White, C W, McCallum, J C, Choudhury, A, Horton, L L, McHargue, C J
• Format: Journal Article
• Language: English
• Published: 14.07.1991
• ISSN: 0257-8972

The formation and annealing behavior of an amorphous layer produced by Sn implantation into sapphire was studied. Tin ions with 180 keV energy were implanted into alpha -Al sub 2 O sub 3 at 300K with fluences ranging from 10 exp 15 -10 exp 17 ions/cm exp --2 . The thermal stability of the damaged layer was investigated with post-implantation annealing treatments at temperatures up to 1375K in either oxidizing or reducing atmospheres. The atomic spatial distribution of the ions was determined by Rutherford backscattering spectroscopy in random and channeling geometries. The structure of the implanted layer was determined by analytical electron microscopy. The degree of disorder was found to increase linearly with fluence up to the threshold for amorphization, approx 1 x 10 exp 16 ions/cm exp --2 . The microstructure of the implanted layer after the thermal treatments depended on the annealing atmosphere. The well known amorphous - > gamma -Al sub 2 O sub 3 - > alpha -Al sub 2 O sub 3 phase transition was observed during annealing in a reducing atmosphere. However, anneals in an oxidizing environment led to the formation of the compound SnO sub 2 , which was found to stabilize the cubic gamma -Al sub 2 O sub 3 phase.