Influence of the Deposition Temperature on the c-Si Surface Passivation by Al[sub 2]O[sub 3] Films Synthesized by ALD and PECVD

Abstract

The material properties and c-Si surface passivation have been investigated for Al 2 O 3 films deposited using thermal and plasma atomic layer deposition ALD and plasma-enhanced chemical vapor deposition PECVD for temperatures T dep between 25 and 400C. Optimal surface passivation by ALD Al 2 O 3 was achieved at T dep = 150-250C with S eff 3 cm/s for 2 cm p-type c-Si. PECVD Al 2 O 3 provided a comparable high level of passivation for T dep = 150-300C and contained a high fixed negative charge density of 6 10 12 cm -2 . Outstanding surface passivation performance was therefore obtained for thermal ALD, plasma ALD, and PECVD for a relatively wide range of Al 2 O 3 material properties.