Influence of Ion Incidence Angle on the Implantation Characteristics of 60 keV Oxygen Ions in Aluminium: A SRIM/TRIM Simulation Study

Abstract

 The implantation geometry of energetic ions controls penetration depth, reflection and collision-cascade morphology. Here, the influence of incidence angle on 60 keV oxygen-ion implantation into aluminium was evaluated using the Monte Carlo Binary Collision Approximation implemented in SRIM/TRIM. At each angle (6°, 12°, 18°, 24° and 30°, measured from the surface normal), 100,000 incident ions were simulated using a displacement energy of 25 eV, lattice binding energy of 3 eV and surface binding energy of 3.36 eV. Increasing the angle from 6° to 30° reduced the longitudinal projected range from 120.6 to 105.7 nm (12.35%) and increased backscattered ions from 391 to 998 (155.24%), corresponding to backscattering fractions of 0.391% and 0.998%. In contrast, the lateral projected range increased from 35.1 to 63.5 nm (80.91%), radial range from 53.9 to 77.2 nm (43.23%), lateral straggle from 43.8 to 73.3 nm (67.35%), and radial straggle from 27.5 to 34.4 nm (25.09%). Longitudinal straggle changed only from 39.8 to 39.4 nm, while vacancy production remained 315 vacancies per incident ion at every angle. The results show that increasingly oblique incidence produces a shallower but substantially broader near-surface affected volume and enhances reflection without changing the reported gross displacement yield. These findings provide a quantitative basis for selecting oxygen-implantation geometry in aluminium surface engineering, thin-film processing and oxide-layer design. Experimental depth profiling and phase analysis remain necessary before inferring retained oxygen concentration, alumina formation or property improvement.