溅射气压对AlN薄膜纳米结构和纳米力学性能的影响

研究在不同气压下,运用射频磁控溅射法在Si（100）上沉积氮化铝（AlN）薄膜,并使用XRD、SEM、AFM、XPS和纳米压痕等表征手段研究薄膜的性质。XRD结果表明,在低压下有利于沉积c轴取向的薄膜,而在高气压下有利于（100）面的生长。SEM和AFM结果表明,随着气压的升高,沉积速率和表面粗糙度均减小而表面粗糙度则增加。XPS结果表明,降低气压有利于减少薄膜中的氧含量,从而使制备的薄膜成分更接近其化学计量比。通过测试AlN薄膜的纳米力学性能表明,在0.30 Pa下制备的薄膜具有最大的硬度和弹性模量。

Effects of sputtering pressure on nanostructure and nanomechanical properties of AlN films prepared by RF reactive sputtering

Wurtzite aluminum nitride（AlN） films were deposited on Si（100） wafers under various sputtering pressures by radio-frequency（RF） reactive magnetron sputtering. The film properties were investigated by XRD, SEM, AFM, XPS and nanoindenter techniques. It is suggested from the XRD patterns that highly c-axis oriented films grow preferentially at low pressures and the growth of（100） planes are preferred at higher pressures. The SEM and AFM images both reveal that the deposition rate and the surface roughness decrease while the average grain size increases with increasing the sputtering pressure. XPS results show that lowering the sputtering pressure is a useful way to minimize the incorporation of oxygen atoms into the AlN films and hence a film with closer stoichiometric composition is obtained. From the measurement of nanomechanical properties of AlN thin films, the largest hardness and elastic modulus are obtained at 0.30 Pa.