氢气流量对类金刚石薄膜结构与性能的影响

Effect of Hydrogen Flow on Structure and Properties of Diamond Like Carbon Films

采用直流/射频耦合反应磁控溅射法在Si(100)衬底上成功制备出类金刚石(DLC)薄膜。利用表面轮廓仪、Raman光谱仪、X射线光电子能谱仪表征所制备薄膜在不同氢气流量下的沉积速率和化学结构,讨论了氢气流量对薄膜沉积速率和化学结构的影响;利用纳米压痕技术及曲率弯曲法表征薄膜的力学性能;利用扫描电镜和原子力显微镜表征薄膜的表面形貌与粗糙度。研究表明:随着氢气流量的增加,所制备薄膜的沉积速率逐渐减小,而薄膜中sp3键的含量逐渐增大。当氢气流量为25mL/min时,薄膜中sp3键的含量为36.3%,薄膜的硬度和体弹性模量分别达到最大值17.5GPa和137GPa。同时,所制备薄膜的内应力均低于0.5GPa,有望成功制备出低内应力的高质量DLC厚膜。随着氢气流量的增加,DLC薄膜的表面变得更致密光滑,且表面均方根粗糙度由5.40nm降为1.46nm。

Diamond like carbon（DLC）films were deposited on Si（100）substrate by coupling DC and RF reactive magnetron sputtering.The deposition rate,the chemical structure,the surface roughness,the surface morphology and the mechanical property were studied.The thicknesses of DLC films were measured by the surface profiler technology.The chemical compositions of DLC films were characterized by Raman spectroscopy and X-ray photoelectron spectroscopy（XPS）.The mechanical properties of DLC films were investigated by nanoindentation techniques and the stress in DLC films was measured by substrate curvature method.The surface roughness and surface morphology were characterized by atomic force microscopy（AFM）and scanning electron micros-copy（SEM）,respectively.It is found that the deposition rate decreases,while the sp3 content in the DLC films increases with the hydrogen flow.When the hydrogen flow is at 25mL/min,the sp3 content reaches 36.3%,and the hardness and modules of films reach the maximum value of 17.5GPa and 137 GPa,respectively.The internal stress of DLC films prepared at different hydrogen flows is less than 0.5GPa.The coupling DC and RF reactive magnetron sputtering may be really an effective method to prepare high quality thick DLC films with low internal stress.When the hydrogen flow increases,the surface of the DLC films becomes denser and smoother,the surface root mean square roughness decreases from 5.40 nm to 1.46 nm.