国外刊物论文译文选登(1)
发布时间:2011/10/13 阅读:28299
2.4. Gas phase composition | 2.4气相成分 | |
The overall gas phase composition also determines the concentration of the growth species. The deposition of diamond is possible in a wide range of different gas combinations, whereby CH4-H2 and CH4-O2-H2 are the basic systems. Generally an increasing concentration in CHx compounds leads to ballas deposition. Literature reported for the transition between faceted crystals and ballas range between 1.5% CH4 and 11% CH4. These large differences are caused by all the other parameters, such as filament temperature, filament substrate distance, gas speed in the reactor, etc., which can vary in wide ranges. | 整个气相成分也可决定生长物质的浓度。金刚石能在各种各样的气体组合物中分解,其中CH4-H2和CH4-O2-H2是两大基本系统。通常情况是,CHX 化合物中浓度增大会导致半刚石沉积。文献报道了小平面晶体和半刚石在1.5%CH4-11%CH4之间的转变。产生这些巨大差别的原因是诸如反应器中的丝 极温度、丝极基体距离、气体速度等所有其它参数,这些参数的范围很宽。 | |
C60 fulleren was also used as carbon source. These experiments were carried out in Ar atmosphere with varying hydrogen additions(10-2 Torr C60, 90-99% Ar, rest H2). Because under such deposition conditions the ratio at. H/C is low, nano-crystalline (ballas) diamond is formed. This effect is not specific for the use of C60 as carbon source because it was shown with experiments that – at a constant CH4 concentration of 1%-the H2/Ar ration was varied. The experiments with Ar addition showed the transition from faceted to ballas growth between 10% and 20% H2 in the mixtures. Similar to the depositon in H2 carrier gas a decrease in the layer growth rate was observed at high Ar contents(nano-crystalline deposition). |
C60添加剂也被用作碳源。这些实验是在加入不一样多的H2的氩气气氛中完成的(10-2Torr C60, 90-99%Ar, 其余为H2)。因为在这样的沉积条件下,H/C比率很低,所以形成了纳米晶(半刚石)金刚石。这种影响在C60用作碳源时不明确,因为实验表明,在CH4 浓度固定为1%时,H2/Ar比率发生变化。加入Ar的实验说明了混合物中氢气在10%-20%间多面金刚石和半刚石生长的转变过程。与用H2作载体气体的沉积相同,氩气含量较高时涂层生长速率减小(纳米晶沉积)。 |