低压气相生长金刚石薄膜成核机理的研究

THEORETICAL STUDY OF NUCLEATION MECHANISM IN DIAMOND THIN FILMS GROWTH BY LOW PRESSURE VAPOR PHASE

本文论述了低压气相生长金刚石薄膜中活性原子团ＣＨ＿３和原子态氢在金刚石成核运动中的作用以及衬底材料性能对成核的影响，认为活性基ＣＨ＿３是生长金刚石的主要活性物质，它们在衬底表面的吸附、碰撞、聚集等构成了成核运动，原子氢在成核运动中的主要作用是参与ＣＨ＿３的脱氢反应和石墨相碳原子团的刻蚀反应，并且还有稳定ＣＨ＿３中ＳＰ￣３杂化轨道的作用。衬底材料性能对成核的影响在于晶格失配而导致的错配位错和晶格畸变所引起的界面势垒和晶核弹性能的增加。最后讨论了金刚石薄膜与衬底之间是否存在过渡层问题，认为过渡层不是金刚石唯一的成核区，它的存在与生长条件密切相关，并且解释了关于过渡层实验研究中遇到的相互矛盾的结论。

The role of the active radical CH_3 and atomic hydrogen H in diamond film growth by low pressure vapour phase and the effect of substrate materials and morphoiogy on diamond nucleation have been theoretically stud ied.It has been suggested that active ladical CH_3 is the main active material in diamond gr-owthand it′s adhesion,collision and concentration on the substrate surface com-pose the process of nucleation. The main role of atomic hydrogen H in the process of nucleation is taking part in dehydrogenating reaction of CH_3 and et-ching reaction of carbon cluster of graphite phase. It also stabilizes the hybridi-zation of sp￣3 in CH_3.The effect of substrate material on nucleation is due to interface potential barrier and the increase of elastic energy of host crystal.Finally, we have discussed there is the transient layer between diamond filmand substrate or not.It has been shown that the transient layer is not onlyregion of nucleation and it′s existence is closely related to growth conditions.Thecontradictions results in experimental research of the transient layersere explained.