溅射气压对Al_2O_3薄膜的结构与电性能的影响

Influence of Sputtering Pressure on Microstructures and Dielectric Properties of Al_2O_3 Thin Films

以纯铝为靶材,在不同溅射气压下采用直流磁控反应溅射方法制备了Al2O3薄膜。用扫描电镜(SEM)、能谱仪(EDS)、X射线衍射仪(XRD)、台阶仪、绝缘电阻仪和精密阻抗分析仪等分析了薄膜的表面形貌、化学成分、结构、薄膜厚度和电学性能。结果表明,随着溅射压力增大,薄膜的颗粒尺寸和厚度减小,组织细密;薄膜的化学成分主要为Al、O元素,铝氧原子比接近2:3,在250℃的低温下,溅射态的Al2O3薄膜均为非晶结构,溅射压力对Al2O3薄膜的结构和化学成分影响不明显;溅射压力为1.0Pa时的薄膜,其电阻和电阻率较大,介电性能相对较好。

Al2O3 thin films were prepared by using dc reactive magnetron sputtering with pure aluminum target at different sputtering pressures. The surface morphology, chemical composition, properties of the Al2O3 films are examined by scanning electron microscopy （SEM） （ EDS）, X-ray diffraction （ XRD）, step profiler, insulation resistance tester and microstructures and dielectric , energy dispersive spectrometer impedance analyzer, respectively.The results shown that as the sputtering pressure increasing, the grain size and thickness of Al2O3films decreases and the surface of Al2O3 films were smooth and compact. It also shown that Al2O3 films deposited at different sputtering pressures at 250℃ temperature were amorphous and the chemical composition of thin films is mainly Al,O atoms, aluminum oxygen atom ratio close to 2： 3. When the sputtering pressure is 1.0 Pa, Al2O3 films have greaterresistance and resistivity, good dielectric properties.