High growth rate deposition of diamond particles and thin films in arc and/or glow discharge region.

用微波或直流放电等离子体化学气相沉积（CVD）方法生长了金刚石薄膜和颗粒，并在立方氮化硼表面上进行了金刚石的外延生长。金刚石薄膜可以以约3000埃/秒的生长速率可重复地生长。h，并且发现所获得的膜的质量是优异的，除了包括在膜和颗粒中的晶格缺陷。对于金刚石的高速沉积，揭示了直流放电等离子体CVD是相当有用的。高质量薄膜的生长速率约为20 μ m/h。另一方面，如果这种方法是在高甲烷浓度（2 - 3%）和高的电功率密度下操作，生长速率增加到约100- 200 μ m/h。直流放电等离子体CVD金刚石生长过程中的等离子体的特性测量的朗缪尔单探针法和发射光谱。对于甲烷和氢气的源气系统（气体比 ...更多信息 ：CH_4/H_2=2/100，总气压为2.6 × 10 ~ 4Pa）时，得到了等离子体正柱中氢原子和电子的统计温度分别为4.8- 5 × 10 ~ 3 K和1- 1.1 × 10 ~ 5 K，电离态的数量很少（-10 ~5K<-7>）。通过计算这些温度区气体分子的平衡常数，发现99%以上的分子都是电离态的从这些结果可以看出，在低压下，碳原子和氢原子的制备对金刚石的生长起着重要的作用。还不能进行外延生长。其原因是由于氢等离子体中衬底表面的稳定性。然后，立方氮化硼表面被用作衬底。结果表明，金刚石薄膜可以沿平行于衬底表面的方向外延生长。通过控制衬底温度和活性组分过饱和度，可以获得（100）和（111）晶面的金刚石单晶薄膜，但在工业应用中金刚石颗粒的生长还存在一些问题。少

Diamond thin films and particles have been grown by micro-wave or DC discharge plasma chemical vapor deposition(CVD) and the epitaxial growth of diamond has also been performed on cubic born-nitride surfaces.By using micro-wave CVD, diamond thin films can be grown reproducibly with the growth rate of about 3000A/h and it is found that the quality of the films obtained is excellent except the lattice defects included in the films and particles.For high rate deposition of diamond, it is revealed that DC discharge plasma CVD is quite useful. The growth rate of the films is about 20mum/h for the high quality one. On the other hand, if this method is operated under high methane concentration(2 3%)and high electric power density, the growth rate increases to about 100-200mum/h.The characteristics of the plasma during diamond growth by DC discharge plasma CVD are measured by the Langmuir single probe method and emission spectrometry. For the source gas system of methane and hydrogen(gas ratio … More : CH_4/H_2=2/100, total gas pressure:2.6 10^4 Pa), it is found that the statistical temperatures of hydrogen atoms and electrons in the positive column of the plasma are obtained to be 4.8-5x10^3K and 1-1.1x10^5K respectively, and the amount of ionized species is fairly small(-10^<-7>).By calculating the equilibrium constant of gas molecules in these temperature regions, it is found that the molecules over 99% (H_2 and CH_4) are decomposed to the neutral H and C atoms.From these results, the preparation of atomic carbon and hydrogen plays important role for the growth of diamond at a low pressure.In many experiments of diamond growth, the films grow in polycrystalline state. The epitaxial growth can not be performed yet. The reason of this fact is due to the stability of the substrate surfaces in hydrogen plasma.Then, the cubic boron-nitride surfaces are used as a substrate. It is found that the diamond thin films can be grown epitaxially with the parallel orientation to the substrate surfaces. The single crystal films of diamond with (100) and (111) planes can be obtained with the detailed control of substrate temperature and supersaturation of active species.There remained some problems for the growth of diamond particles useful for industrial fields. Less