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化学汽相沉积金刚石生长表面的悬挂键是其赖以成核和生长的表面活性格点。但是两个以上悬挂键聚集在一起时,局部表面能量比较高,悬挂键之间容易发生重构,形成π键或者dimer键,成为石墨结构的生长基样点。因此,金刚石的生长主要依赖于表面上的单个悬挂键集团和气相中的碳氢活性基团。石墨则主要依赖于表面上的多个悬挂键组成的集团,石墨的生长可以被表面附近活性氢原子的刻蚀作用所抑制。对表面悬挂键的微观分布状态的统计计算结果表明,(111)和(100)生长表面的氢原子覆盖率分别为0.86单层(ML)和0.80ML时,单位表面积上的单个悬挂键团密度最高,金刚石的生长速率为最大极值。对于同时显露(111)和(100)面的多晶金刚石膜生长表面,则表面的氢原子最佳覆盖率应为0.83ML。
The dangling bonds of chemical vapor deposited diamond growth surface are the surface active lattices that they depend on for nucleation and growth. However, when two or more dangling bonds are clustered together, the energy of the local surface is relatively high, and the dangling bonds are easily reconstructed to form π bond or dimer bond, which becomes the basis for the growth of the graphite structure. Therefore, diamond growth depends mainly on the surface of a single dangling bond group and the hydrocarbon active groups in the gas phase. Graphite mainly relies on groups of dangling bonds on the surface. The growth of graphite can be inhibited by the etching of active hydrogen atoms near the surface. The statistical calculation of the microscopic distribution of the surface dangling bonds shows that when the hydrogen atom coverage of (111) and (100) growing surfaces is 0.86 single layer (ML) and 0.80ML respectively, the single dangling bond density Highest diamond growth rate is the maximum. For polycrystalline diamond film growth surfaces that simultaneously expose the (111) and (100) planes, the optimum coverage of hydrogen atoms on the surface should be 0.83 ML.