Atomic layer deposition of tantalum oxide and tantalum silicate from TaCl5, SiCl4, and O3: growth behaviour and film characteristics

摘要: Tantalum oxide (Ta2O5) and tantalum silicate (TaSiOx) films were grown by atomic layer deposition from TaCl5, SiCl4, O3. Saturation of absorption was observed for TaCl5 at short pulses. However, long exposure resulted in a reduced growth per cycle Ta2O5 TaSiOx due to concomitant etching. The saturated ∼0.77 A temperature 300 °C ∼1 250 °C. Quadrupole mass spectrometry revealed that chemisorbed on the surface with negligible ligand removal. Subsequently, reaction O3 led formation both chlorine oxides (ClxOy) (Clx) as by-products. Si incorporation found be feasible using supercycles including SiCl4/O3 cycles although no SiO2 only. At °C, self-limiting function SiCl4 pulse time. This suggests adsorption Ta-terminated surfaces is more favorable than Si-terminated ones, similar case equivalent H2O-based ALD process. Cl impurity levels lower those H2O. amorphous deposited. crystallized into orthorhombic β-Ta2O5 740 while showed signs crystallization up 900 Amorphous Ta0.6Si0.4Ox dielectric constants 31 24, respectively, exhibited leakage current densities deposited