Deposition of High Quality Diamond Film on Beam-Irradiated Surface Using ECR Plasma

利用磁微波等离子体大面积化学气相沉积金刚石已成为可能。该系统的关键是在沉积区设置电子回旋共振（ECR）条件。在该区域可以获得金刚石形成所需的高等离子体密度。在0.1Rorr的气压下，当等离子体中出现大量回旋时，在高于ECR条件的磁场中，即在所谓的非共振模式下，微波的有效吸收使等离子体密度增加。在低压下，金刚石可以在正偏压的衬底上形成，但在负偏压的衬底上不能形成。加速离子不适合于金刚石的形成。原子碳或含一个碳原子的简单基团可能是气相生成金刚石的活性物种的候选者，在SiO_2点阵Si衬底上选择性地生成了高质量的金刚石颗粒。为了在SiO_2点的边缘等所需的位置形成晶核，使用Ar束倾斜照射图案化的基底。等离子体CVD沉积后，金刚石颗粒选择性地生长在SiO_2点的边缘，根据图案。金刚石的这种选择性生长实现了具有相同晶粒尺寸的多晶。

Large-area chemical vapour deposition of diamond has become feasible using magneto-microwave plasma. The important point of the deceloped system is to set the electron cyclotron resonance (ECR) condition at the deposition area. The high plasma density necessary for diamond formation can be obtained at the area. Under a pressure of 0.1 Rorr, where ample gyrations occurs, the plasma density has been increased by the effective microwave absorption in a magnetic field higher than ECR cndition, i.e. in the so-called off-resonance mode. In the low pressure diamond has been formed on positively, but not on negatively biased substrates. accelerated ions are not suitable for diamond formations. Aomic carbon or a radical having a simple form, containing one carbon atom, might be a candidate for the acitive species to form diamond from the vapour phase.High quality diamond particles have been selectively formed on SiO_2 dot-patterned Si substrate. To form nuclei at desired sites, such as the edges of SiO_2 dots, Ar beam is used to irradiate obliquely the patterned substrates. After deposition using plasma CVD, diamond particles selectively grow on the edges of SiO_2 dots according to the pattern. This selective growth of diamond have realized polycrstals with the same grain size.