HfO2 and Hf1-xSiO2 deposition by MOCVD using TDEAH

We synthesized tetrakis-diethylamido-hafnium (Hf(NEt2)(4)) and tris-diethylamino-silane (HSi(NEt2)(3)) as precursors of Hf and Si for depositing HfO2 and Hf1-8SixO2 thin films. Both precursors are liquid at room temperature and have moderate vapor pressure enough for chemical vapor deposition process. By using the Hf NEt2)(4)/O-2 gas system, the stoichiometric HfO2 film with little residual impurities was deposited by low pressure CVD. The HfO2 film was polycrystalline and had good step coverage quality. By supplying the HSi(NEt2)(3) during the HfO2 deposition, Hf1-xSixO2 was deposited. As increasing the amount of supplied HSi(NEt2)(3), the ratio of Si to Hf in the film was increased and the refractive index was decreased. The Hf1-xSixO2 was amorphous and had slightly degraded step coverage quality as compared with HfO2.