Exposure of AlN and Al2O3 to low energy D and He plasmas

Abstract

Aluminum nitride (AlN) and aluminum oxide (Al2O3) were exposed to deuterium (D) and helium (He) plasma in the PISCES-A linear plasma device using RF biasing of the sample manipulator to set the incident ion energy (16–100 eV, 0.7–12 × 1025 m−2, <600 K). Preferential sputtering of nitrogen was detected for D and He exposed AlN samples, resulting in Al enrichment at the surface (i.e., Al/N ~2–3). The Al-enriched region was limited to the uppermost ~20 nm, independent of fluence, and was eliminated by exposure to plasma seeded with nitrogen. No Al enrichment was observed for the Al2O3 samples exposed to pure D or He. Results suggest AlN and Al2O3 are promising candidates as plasma facing materials in magnetic fusion and RF plasma devices (e.g., as electrical standoffs and RF heating windows).

Keywords

• Aluminum nitride
• Aluminum oxide
• Deuterium
• Helium
• Preferential sputtering