Comparative Studies of Atomic Layer Deposition and Plasma-Enhanced Atomic Layer Deposition Ta2O5 and the Effects on Electrical Properties of In situ Nitridation

Ta 2 O 5 and TaO x N y thin films were deposited by atomic layer deposition (ALD) from Ta(NMe 2 ) 5 (PDMAT) with water, oxygen plasma, and nitrogen added oxygen plasma. The film properties were comparatively investigated focusing on the electrical properties from metal oxide semiconductor capacitor structure with 10 nm Ta 2 O 5 or TaO x N y . The results show that plasma-enhanced ALD (PE-ALD) Ta 2 O 5 film has better electrical properties including lower interface state density and leakage current than thermal ALD. Moreover, PE-ALD TaO x N y shows the best properties, indicating the beneficial effects of in situ nitridation. Especially, time dependent dielectric breakdown was significantly improved up to 4000 times of thermal ALD Ta 2 O 5 . These results show that, intentional in situ nitrogen incorporation with good electrical properties was successfully achieved by PE-ALD using nitrogen–oxygen mixture.