【作者】 苏颖；

【导师】 李红东；

【作者基本信息】 吉林大学 ， 凝聚态物理， 2012， 硕士

【摘要】 近年来，大尺寸化学气相沉积（CVD）金刚石单晶的高速生长和性质研究，引起国内外众多研究者的关注,引入不同气氛高速生长CVD金刚石单晶成为其中研究热点之一。本论文采用微波等离子体CVD（MPCVD）方法，在H2：CH4=750sccm：90sccm的气氛条件基础上，分别引入不同形式的氮氧元素（氮气N₂，氧气O2，笑气N₂O）在高温高压法（HTHP）合成的Ib型（100）金刚石单晶籽晶上同质外延生长金刚石单晶。对样品进行显微镜、OES、Raman、PL光谱以及SEM、AFM表征，研究了氮、氧引入后对CVD金刚石单晶生长速率、生长机制以及质量、光学性能等的影响。在反应气氛中引入N₂O，CVD金刚石单晶的生长速率在氮、氧基团共同作用下，有较大的提高，最大速率达到135μm/h。Raman光谱和PL光谱研究表明，引入2sccm N₂O时，样品的氮含量最少、质量最好。不同N₂O流量条件下生长的金刚石单晶表面形貌变化很大。适当引入N₂O，金刚石表面刻蚀坑尺寸和数量减少，显露出典型的台阶流动生长模式。氧、氮对台阶传播的竞争作用，使得生长出形貌较好的金刚石成为可能，为CVD金刚石单晶的多次生长奠定了良好基础，有利于大尺寸单晶的合成。与其他气体（N₂和O2）相比，引入N₂O生长金刚石有助于提高金刚石的生长速率，同时保持良好的品质，对高速生长高品质金刚石单晶有积极作用。更多还原

【Abstract】 Single crystal diamond attracted many researchers’ attention because of itsexcellent properties. However, limited by their size, doping and cost, natural andhigh-pressure high-temperature （HPHT） diamonds are unsuitable for applications.Single crystal diamond synthesized by MPCVD technique becomes the mostpromising method.In this work, nitrogen-and oxygen-related radicals was generally introduced inthe reaction atmosphere （H2：CH4=750sccm：90sccm） with different modalities（N₂，O2，N₂O） to synthesize homoepitaxy single crystal diamonds. The sampleswere tested by microscopy, optical emission spectroscopy （OES）, Raman,photoluminescence （PL），SEM and AFM.For an appropriate addition of N₂O （at2sccm）, the product presents the highestgrowth rate （135μm/h） and narrowest FWHM （2.59cm-1） of diamond Raman peak.Moreover, introducing N₂O can result in the density of the large-sized pits decrease onthe top surface of SCDs. These facts are expected to realize the long-term stabledeposition required for large crystals production. The surface roughness and color areboth in respect to the N-related content. The CVD SCDs grown with N₂O are of highquality, high growth rate, smooth surface, and/or enhanced transparency with respectto the products grown with the additions of N₂or O2. It is demonstrated that thecombined effect of N-and O-related radicals generating from N₂O in the CH4/H2plasma ambient is significant to achieve high quality and high-rate growth ofhomoepitaxial CVD SCDs.更多还原