高离化率磁控溅射薄膜制备及形成机理研究

Due to the presence of the “shadow” effect, the films flaking, different film thickness and uncoated hole will appeared on the component different plane with complex shape, which is coated by conventional magnetron sputtering technique. In order to eliminate “shadow” effect and fabricated high density TiN or CrN film with same thickness, structure and properties on different plane of the complex shape components, the degree of Ti or Cr atom ionization is increased by high-power pulsed magnetron sputtering (HPPMS) and the ion flux, incident direction and energy can be controlled. The key factor of affect the degree of ionization is studied in this project. The degree of the atom ionization and the ion energy can be controlled by HPPMS parameter. The effect of HPPMS ionization rate, the ion energy and ion initial incident angle (sample surface tilt angle) on the films microstructure and properties is come up and the film growth mechanism of the HPPMS also is discussed. Then plasma sheath and electric field distribution simulation analysis on the different tilt angles plane of the complex shape component are studied. The effect of the plasma density and electrical field strength on the ion energy and flux also are discussed. The homogeneous films with excellent properties are synthesized on the complex shape component surface by HPPMS through controlling ionization rate, bias and pressure preparation performance, which will improve the key components life of the defense industry .

由于存在“阴影”效应，常规磁控溅射技术在形状复杂的零部件表面制备薄膜，会出现薄膜厚度不均匀、局部脱落、孔洞处无法实现镀膜等问题。按照NSAF联合基金的要求，本项目采用高功率脉冲磁控溅射（HPPMS）技术，提高钛、铬溅射原子的离化率，控制薄膜沉积时离子的通量、入射方向及能量，消除“阴影”效应，在复杂工件的各个平面得到致密度高、厚度、结构、性能相同的均质氮化钛、氮化铬薄膜。本项目研究了影响HPPMS离化率关键因素，实现了对溅射原子的离化率及离子能量调控。在揭示HPPMS离化率、离子能量及离子初始入射角度（样品平面倾斜角度）对薄膜结构、性能影响机制及HPPMS薄膜生长机制的基础上，模拟分析复杂形状零件各不同倾斜角度平面上等离子体鞘层、电场分布及其对离子的能量、通量的影响，调控离化率、偏压和气压，利用HPPMS在复杂形状零件表面制备性能优异的均质薄膜，提高国防工业关键零部件寿命。

由于存在“阴影”效应，常规磁控溅射技术在形状复杂的零部件表面制备薄膜，会出现薄膜厚度不均匀、局部脱落、孔洞处无法实现镀膜等问题。本项目采用高功率脉冲磁控溅射（HPPMS）技术，提高钛、铬溅射原子的离化率，控制薄膜沉积时离子的通量、入射方向及能量，消除“阴影”效应，在复杂工件的各个平面得到致密度高、厚度、结构、性能相同的均质氮化钛、氮化铬薄膜。本项目首先系统研究了电源属性(限流电阻、频率、脉宽、电流、电压、峰值功率、平均功率等)、气体压力、基体偏压等对金属离子离化率、离子能量的影响，探讨了影响靶材离化率及离子能量的关键因素。在此基础上本项目研究了溅射原子的离化率、离子能量对薄膜组织结构、表面应力状态、致密度、膜基界面及性能的影响及高功率脉冲磁控溅射制备薄膜的生长机理，同时研究了样品倾斜角度（即溅射离子初始入射角度）对沉积薄膜结构及性能的影响。最后本项目进行了高功率脉冲磁控溅射薄膜厚度均匀性与靶基距关系模拟研究分析；采用PIC/Monte Carlo的方法，以半球模型为例，模拟研究了在45°倾斜角度下，半球表面涂层沉积厚度；同时用有限元方法模拟了直流辉光放电时“碗形”工件表面的等离子电势、电场分布、带电粒子在真空室中的输运以及在半球工件内表面的沉积过程，获得了基体偏压、真空室压强等工艺参数对沉积粒子通量、能量及粒子入射角度的影响规律，为控制带电粒子在异型工件表面的沉积提供理论依据，为在复杂样品表面制备均匀薄膜奠定了基础。本项目采用高离化率磁控溅射镀膜技术使靶材溅射原子的离化率达60%以上，揭示了影响溅射靶材离化率及离子能量的关键因素，实现对溅射原子离化率及离子能量的调控。在此基础上，在不同倾斜角度(离子初始入射角度)样品上制备了结构、性能均匀的薄膜材料，为在复杂形状工件上制备结构、性能均匀的金属及氮化物薄膜奠定了基础。相关结果在国内外重要材料期刊发表SCI论文11篇，授权发明专利3项。