TiO_2薄膜的MOCVD法制备及其退火条件的研究

Preparation of TiO_2 Thin Films by MOCVD and Influence of Post-annealing Conditions on Their Properties

用金属有机化合物气相淀积(MOCVD)法在n-Si(100)单晶衬底上制备了TiO2薄膜;利用X-射线衍射技术研究了不同条件下退火的TiO2薄膜的结晶性;通过测量C-V曲线和BT实验分别研究了TiO2/Si系统的固定电荷密度和薄膜中的可动电荷密度。实验结果表明,只有在一定的退火温度下薄膜才有较好的结晶性。在退火温度为850°C、退火时间为30min时,可得到完全为金红石相的TiO2薄膜,其固定电荷密度的数量级为1011/cm2,可动电荷密度在(3～4)×1011/cm2,电荷极性为正。

TiO2 thin films are prepared on nSi (100) substrate by MOCVD.After postannealed under different conditions,the crystallinity of the films was studied by Xray diffraction (XRD) technique.By measuring CV curve and by standard biastemperature test (BT test),fixed charge density in TiO2/Si system and movable ions density in TiO2 films were studied.Results show that desired crystallinity is acquired at certain annealing temperature.The crystallinity of these films shows only rutile when they are annealed at 850 °C for 30 min.The fixed charge density is calculated at the order of 1011/cm2 and the calculated movable ions density is (3～4)×1011/cm2 and the movable ions are positive.