衬底温度对溅射法生长Cu-Al-O薄膜性能的影响

The Effect of Substrate Temperature on the Properties of Cu-Al-O Thin Films Prepared by Sputtering

使用多晶CuAlO2陶瓷靶,利用射频磁控溅射法沉积Cu-Al-O薄膜。傅立叶变换红外光谱显示薄膜中存在与CuAlO2相关的Cu—O,Al—O和O—Cu—O键。在可见光范围内Cu-Al-O薄膜具有较好的透过性,衬底温度为400℃～500℃时薄膜透过率在60%～70%之间,计算拟合得到Cu-Al-O薄膜的直接和间接带隙能分别为3.52eV和1.83eV左右,与多晶CuAlO2薄膜结果一致。在近室温区薄膜符合半导体热激活导电机制,其电导率随衬底温度的升高先增大后减小,500℃沉积的薄膜导电性较好,室温电导率达到2.36×10-3S·cm-1,这可能源于Cu-Al-O薄膜中与CuAlO2相关的键合形成情况的改善。

Cu-Al-O thin films were deposited by RF magnetron sputtering using polycrystalline CuAlO2 target. Fourier transform infrared spectra show the Cu-O, Al-O and O-Cu-O bonding related with CuAlO2 phase. Cu-Al-O thin films show good transparency in the visible range, and the transmittance is 60%-70% for the films prepared at 400℃-500℃. The direct and indirect band gap energies estimated are 3.52 eV and 1.83 eV, which are consistent with those of polycrystalline CuAlO2 film. In the range of close room temperature （RT）, the conductive mechanism of Cu-Al-O thin films belongs to the thermally activated conduction. The electrical conductivity of the films increases and then decreases as the substrate temperature increases. The film deposited at 500℃ has the higher electrical conductivity （RT, 2.36× 10.3 S.cm^-1）, which may be due to the improvement of the structure of Cu-Al-O thin film.