Development of Low-Energy Particle-Beam Sources for Super-fine Plasma Processing

为了实现超精细等离子体加工，应满足以下几个要求：入射到衬底上的离子应具有单色平行速度和低能量，以不引起损伤，并且还需要高通量、均匀和大的束。这些要求将通过开发低压、大面积、高密度、低等离子体电势的等离子体来满足。为此，我们开发了一种新颖的等离子体产生电感耦合射频放电下的表面磁场，多偶极子表面磁场产生以下效果：良好的约束高能电子，增强等离子体的生产，减少体电子扩散损失，并在等离子体密度以及均匀性的增加。在我们的表面磁约束原型装置中，得到了如下令人满意的结果：1。放电等离子体维持在低压，如Torr.2。获得了均匀、大直径（~ 40 cm）、高密度、低等离子体电位（~ 20 V）的等离子体.等离子体电位是可控的外部偏置的小电极。另一方面，我们已经研究了离子诱导的自由基产生的表面上，高能量的多原子离子的碎片在其影响的表面。这种类型的等离子体与表面相互作用令人感兴趣，因为它可以应用于新的自由基束源。

In order to realize super-fine plasma processings, several requirements should be satisfied : Ions incident on a substrate should have a monochromatic parallel velocity and a low energy not to give rise to damage, and also a high-flux, uniform, and large beam is necessary. These requirements will be met by developing a low-pressure, large-area, high-density plasma with the low plasma potential. To do this, we have developed a novel plasma production by an inductively coupled rf discharge under a surface magnetic field.Multi-dipole surface magnetic fields produce following effects ; good confinement of high energy electrons, enhancement of plasma production, reduction of bulk-electron diffusion loss, and the resultant increase in plasma density as well as the uniformity. The decrease in the plasma potential is also expected.Promising results were obtained in our prototype device with surface magnetic confinement as follows :1. The discharge plasma was sustained at low pressures such as Torr.2. A uniform, large-diameter (-40cm), high-density plasma with low plasma potential (-20 V) was obtained.3. The plasma potential was controllable with an externally biased small electrode.On the other hand, we have studied ion-induced radical production on surfaces ; fragmentation of high-energy poly-atomic ions at their impact on surfaces. This type of plasma-surface interactions is of interest since it can be applied to a new source of radical beams.