模具表面改性日益受到人们重视。本文采用二维Particle-in-cell/Monte Carlo Collision模型对等离子体浸没离子注入处理凹模型腔内表面的鞘层动力学及均匀性进行了研究。考察了电压脉宽对鞘层中电势分布、离子的运动状态以及型腔内表面离子注入剂量、能量和角度的空间分布的影响。结果表明随着电压脉宽的增加,凹模型腔内表面的注入剂量不均匀性增加,同时注入到内表面的高能离子数目也增加。脉冲宽度变化对注入角度影响不大,离子以接近垂直的入射角度注入到型腔底部,而在侧壁上离子注入角度接近45°。当脉冲宽度较大时,发现少部分注入到侧壁上的离子以一定角度从下往上注入到样品表面,这是由于碰撞效应造成的。从能量和剂量的角度,存在一个合适的脉冲宽度,过大的脉宽会引起剂量不均匀性增加,同时离子注入能量也会下降。
Plasma surface modification of the inner wall of a slender tube is quite difficult toachieve using conventional means.In the work described here,an inner coaxial radio frequency(RF)copper electrode is utilized to produce the plasma and also acts as the sputtered targetto deposit copper films in a tube.The influence of RF power,gas pressure,and bias voltageon the distribution of plasma density and the uniformity of fihn thickness is investigated.Theexperimental results show that the plasma density is higher at the two ends and lower in themiddle of the tube.A higher RF power and pressure as well as larger tube bias lead to a higherplasma density.Changes in the discharge parameter only affect the plasma density uniformityslightly.The variation in the film thickness is consistent with that of the plasma density along thetube axis for different RF power and pressure.Although the plasma density increases with highertube biases,there is an optimal bias to obtain the highest deposition rate.It can be attributed tothe reduction in self-sputtering of the copper electrode and re-sputtering effects of the depositedfilm at higher tube biases.
