A spectroscopic study of optical centers in diamond grown by microwave-assisted chemical vapor deposition
A spectroscopic study of optical centers in diamond grown by microwave-assisted chemical vapor deposition
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微波辅助化学气相沉积金刚石光学中心的光谱研究
DOI：
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发表时间：
1990
期刊：
影响因子：
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通讯作者：
Y. Sato
中科院分区：
文献类型：
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作者：
A. T. Collins;M. Kamo;Y. Sato
用微波辅助化学气相沉积（CVD）法，用甲烷和氢气生长金刚石单晶和金刚石多晶薄膜，记录了它们的吸收光谱和阴极射线发光光谱。已经进行了调查，以了解CVD金刚石的性质在多大程度上与传统金刚石相似，以及它们在多大程度上是独特的。研究已经取得了作为生长的材料，这还没有被故意掺杂，以及样品已受到辐射损伤和热退火。使用0.5%至1.0%的甲烷浓度生长的单晶显示出明亮的蓝色“带A”发射，也强烈的边缘发射，类似于一些天然的IIa型金刚石的阴极射线发光光谱。这意味着晶体相对没有结构和化学缺陷，这一结论得到了在经受辐射损伤和800 °C退火的晶体的吸收光谱中没有任何零声子线的加强。然而，在辐射损伤之前，光谱确实显示了一种吸收，这种吸收随着能量的增加而逐渐增加，这可能与sp^2键合的碳有关。辐射损伤后的阴极射线发光光谱表明，晶体中含有一些孤立的氮，并且在800 °C下热退火后检测到H3发光，首次证明这些样品含有低浓度的氮对。在甲烷浓度为0.3%~ 1.5%的条件下生长的所有多晶薄膜，其吸收能量随着能量的增加而逐渐增加，这也是由sp ^2键合的碳所引起的。这种吸收在使用较高甲烷浓度生长的膜中更强。在0.3%的甲烷浓度下生长的薄膜也表现出明亮的蓝色阴极射线发光，虽然边缘发射是不可检测的弱。使用更高的甲烷浓度产生的薄膜与证据的阴极射线发光光谱的氮+空位和氮+间隙复合物，以及独特的CVD金刚石的光学中心。一个特殊的缺陷产生在1.681 eV的发射和吸收线。通过用^29 Si离子注入常规金刚石，已经证实该中心涉及硅，并且已经表明，在具有高浓度孤立氮的注入金刚石中，1.681 eV的发光相对更强烈。
Absorption and cathodoluminescence spectra have been recorded for single crystals of diamond and polycrystalline films of diamond, grown by microwave-assisted chemical vapor deposition (CVD) using methane and hydrogen. The investigation has been carried out to see to what extent the properties of CVD diamond are similar to those of conventional diamond, and to what extent they are unique. Studies have been made of the as-grown material, which has not been intentionally doped, and also samples that have been subjected to radiation damage and thermal annealing. The single crystals grown using methane concentrations of 0.5 to 1.0% exhibit bright blue “band A” emission and also intense edge emission, similar to the cathodoluminescence spectra of some natural type IIa diamonds. This implies that the crystals are relatively free from structural and chemical defects, a conclusion which is reinforced by the absence of any zero-phonon lines in the absorption spectra of crystals which have been subjected to radiation damage and annealing at 800 °C. Before radiation damage the spectrum does, however, reveal an absorption which increases progressively to higher energies, and which may be associated with sp ^2-bonded carbon. The cathodoluminescence spectra after radiation damage indicate that the crystals contain some isolated nitrogen, and the detection of H3 luminescence, following thermal annealing at 800 °C, demonstrates for the first time that these samples contain small concentrations of nitrogen pairs. All of the polycrystalline films, grown using methane concentrations between 0.3 and 1.5%, have an absorption which increases progressively to higher energies, and which again is attributed to sp ^2-bonded carbon. This absorption is stronger in the films grown using higher methane concentrations. Films grown at a methane concentration of 0.3% also exhibit bright blue cathodoluminescence, although the edge emission is undetectably weak. The use of higher methane concentrations produces films with evidence in the cathodoluminescence spectra of nitrogen + vacancy and nitrogen + interstitial complexes, as well as optical centers unique to CVD diamond. One particular defect produces an emission and absorption line at 1.681 eV. By implanting conventional diamonds with ^29Si ions it has been confirmed that this center involves silicon, and it has been shown that the 1.681 eV luminescence is relatively more intense in implanted diamonds which have a high concentration of isolated nitrogen.