氮气氛下(100)织构金刚石薄膜的成核与生长研究

利用热丝化学气相沉积法研究了氮气浓度对金刚石薄膜成核和生长的影响.实验发现氮气的 加入对金刚石成核密度影响不大，但促进了已形成的金刚石核的长大.适量的氮气不仅使金 刚石生长速率得到很大的提高，而且稳定了金刚石薄膜(100)面的生长，使金刚石薄膜具有 更好的(100)织构.利用原位光发射谱对衬底附近的化学基团进行了研究.研究表明，氮气的 引入使得金刚石生长的气相化学和表面化学性质发生了很大变化.含氮基团的萃取作用提高 了金刚石表面氢原子的脱附速率，从而提高了金刚石膜的生长速率.而含氮基团的选择吸附 使金刚石 关键词： 氮气 金刚石薄膜 织构 原位光发射谱

THE NUCLEATION AND GROWTH OF (100) TEXTURED DIAMOND FILMS IN PRESENCE OF NITROG EN

We have studied the influence of nitrogen addition in CH₄/H_{2 gas mixtures on the nucleation, morphology and growth rate of polycrystalline diamond films prepared by hot filament chemical vapor deposition (HFCVD). The p resence of nitrogen has little effect on diamond nucleation density, but is bene ficial to enhance the growth rate and to stabilize (100) facets of diamond films . Optical emission spectroscopy was applied to detect the chemical radicals in t he system. It is shown that the additional nitrogen makes the chemical radicals and surface activity of diamond films change tremendously. We believed that nitr ogenous species abstract the atomic hydrogen on the diamond surface and speed up the desorption rate of H, so as to promote the diamond films deposition. Furthe rmore, the selective absorption of nitrogenous species causes chemical roughenin g of the (100) facets, which makes the growth rate of (100) facet higher than th at of other facets and leads to the presence of (100) textured diamond films.}