微弧离子镀环境构建及镀料粒子脱靶机制和沉积行为研究

Aim at the currently technology insufficiencies that hard to acquire uniform film by magnetron sputtering ion plating due to poor around plating ability of plating material particle, and multi-arc ion plating film quality affect by molten state large particles spray usually, meanwhile according to understanding of the essence of target current is parameter that characterized by flux of electron transfer from cathode (target) to anode in chamber, application project plan to based on volt-ampere characteristics at "ohm- - anti-ohm" relation transition interval in gas discharge bimodal curve, which the flux of electron transfer in chamber is dozens of magnetron sputtering and the target voltage is several times of multi-arc ion plating, build a ion plating environment that satisfy micro-arc (strong glow and weak arc) discharge condition by broad pulse highfield. Research the transform discipline of plating material particle leave-target mechanism and film microstructure by discharge condition change from strong glow to weak arc in this environment. Revealing the correspondence of film thickness and plating material particle around plating ability to electric field volt-ampere characteristics. Establish the boundary conditions of plating material particle leave-target mechanism from collide leave-target in sputtering condition pass collide enhance heat emission in micro-arc condition to molten spray leave-target in multi-arc environment. In order to supply the theory support to develop the micro-arc ion plating technology which with set density and smooth in sputtering ion plating and uniform, good around plating ability in multi-arc ion plating advantages as one.

针对当前磁控溅射离子镀因镀料粒子绕镀性差而难以获得厚度均匀的膜层、多弧离子镀易产生熔融态大颗粒喷溅而影响膜层质量这些技术缺憾，和基于对靶电流之本质是真空腔内电子由阴极（靶材）向阳极迁移通量的理解，申请项目拟以气体放电双峰曲线中伏安特性处于"欧姆-反欧姆"关系过渡区间、其时腔内电子迁移通量将数十倍于磁控溅射离子镀、靶电压数倍于多弧离子镀这一非稳态伏安特性为依据，构建依靠宽脉冲强电离电场使真空腔内满足微弧（强辉弱弧）放电条件的离子镀环境；研究该环境中放电条件由强辉向弱弧过渡过程中镀料粒子脱靶机制及膜层微观结构的转变规律；揭示真空腔内膜层厚度和镀料粒子绕镀性与电场伏安特性的对应关系；确立镀料粒子脱靶机制由溅射环境的碰撞脱靶经微弧环境的碰撞增强热发射脱靶向多弧环境的熔融喷溅脱靶转变的边界条件。以期为集溅射离子镀膜层致密光滑和多弧离子镀均匀绕镀性好等优点于一体的微弧离子镀技术的开发提供理论支撑。

针对磁控溅射离子镀因沉积粒子离化率低而引起较难沉积厚度均匀且具有致密微观结构和良好膜基结合强度的薄膜，和多弧离子镀因电弧放电而引起靶材熔融液滴喷发至基体表面降低成膜质量等技术缺憾，本项目基于电工学中等同量变换原理和高频电压震荡技术，构建出具有“微秒级电压、毫秒级电流波形独立调制”的电源模式，并以等离子体物理学中气体放电伏安特性曲线为理论基础，通过对电压与电流精确的微秒级调控将气体放电引入至磁控溅射所处辉光区和多弧离子镀所处弧光区之间的微弧放电区（强辉弱弧区间），此区间具有较大的电场强度和电流密度且电场强度与电流密度呈现反比关系。依据电流本质为带电粒子分别向阴、阳极迁移通量的理解，利用微弧放电区其特性增强真空腔内正离子对阴极靶面的轰击强度与密度，进而诱发靶面因热能涨落而形成的“微区热点”，使靶面由靶面均匀的辉光放电逐步聚缩为弥散的微弧放电，从而实现沉积粒子由磁控溅射的碰撞脱靶向碰撞增强热发射脱靶方式的转变，最终研发出能够获得较大密度和较高离化沉积粒子的一种新型微弧离子镀技术。研究结果表明，微弧离子镀技术将气体放电引入至微弧区间而使沉积粒子以碰撞增强热发射脱靶后具有较高的离子能量及离子通量，由此不仅提高了沉积薄膜沿靶基距方向上的厚度均匀性，而且还能快速制备具有致密微观结构、光滑表面质量和良好综合性能的纯金属或化合物薄膜。