Epitaxial Growth of Diamond on Boron Containing Single Crystals

用直流等离子体CVD法在含硼化合物CBN、BP、重掺硼硅、硼定制硅表面上外延生长了金刚石。在大多数衬底上，除了cBN外，没有观察到外延生长，这是由于在较高的衬底温度下氢的反应对表面的损伤，以及碳原子对表面上存在的硼原子的去除。在CBN(111)表面(B表面)沉积的初始阶段，非常薄的碳层先于金刚石岛的外延生长而开始生长。目前还不清楚这一层的晶体结构。考虑到钻石是在这一薄层上生长的，以后这层薄层的结构将接近钻石的结构。通过扫描电子显微镜观察，发现这一层具有相当明亮的反差。据推测，电子将从层的表面发射出来。我们尝试了电子场发射的初步实验，在相同的表面几何形状下，来自碳层的电子电流比来自钼表面的电流相对较大。这种电子发射体在长周期的实验中相当稳定，我们已经建立了这种简单的装置作为一种新的电子发射体。

Epitaxial growth of diamond on boron containing compoud such as cBN, BP, heavily boron doped Si, boron tailored Si surface has been performed using DC plasma CVD method. On most of the substrates, epitaxial growth cannot be observed except cBN.The reason of this fact is due to the surface damages by reaction of hydrogen under the higher substrate temperature and also the removal of born atoms existing on the surface by carbon atoms.At the initial growth stage of deposition on cBN (111) surface (boron surface), the very thin carbon layrts start to grow prior to the epitaxial growth of diamond islands. The Crystal structure of this layr is not known well at this moment. Considering the fact that diamond grows eptaxially on this thin layr, the structure of this thin later will be close to the structure of diamond.By SEM observation, it is found that this layr gives quite bright contrast. It is supposed that electrons will be emitted from the surface of the layr. We have tried the preliminary experiment of field emission of electrons The electron current from the carbon layr is relatively high compared with the current from molybdeum surface in the same sruface geometry. This electron emitter words quite stable for the long period experiment.We have fablicated the simple device working as a new electron emitter.