Nucleation of cubic boron nitride on boron-doped diamond via plasma enhanced chemical vapor deposition
Nucleation of cubic boron nitride on boron-doped diamond via plasma enhanced chemical vapor deposition
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等离子体增强化学气相沉积立方氮化硼在掺硼金刚石上的形核
DOI：
10.1063/5.0145771
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发表时间：
2023-06
影响因子：
3.2
通讯作者：
Jesse M. Brown;Saurabh Vishwakarma;David J. Smith;R. Nemanich
中科院分区：
文献类型：
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作者：
Jesse M. Brown;Saurabh Vishwakarma;David J. Smith;R. Nemanich
立方氮化硼(c-BN)与金刚石有1.4%的晶格失配，是一种具有多种电子器件应用机会的异质结构。然而，c-BN/金刚石异质结构的形成受到在界面形成六方BN的倾向的限制。本研究利用电子回旋共振等离子体增强化学气相沉积(ECR-PECVD)技术，采用氟化学方法，在自支撑多晶和单晶掺硼金刚石衬底上沉积了c-BN。用原位x射线光电子能谱(XPS)研究了氮化硼(BN)薄膜的成核和生长过程与氢气流量的关系。结果表明，随着氢气流量的增加，BN的PECVD生长速率增大。在没有氢气流动的情况下，BN层的厚度减小或被刻蚀。XPS结果表明，过量的氢气显著增加了以六方氮化硼(h-BN)为特征的sp2成键比例，尤其是在初始层生长过程中。减少氢气流量，使氢气成为限制反应物，可以最大限度地减少BN成核过程中的sp2键。透射电子显微镜结果表明，金刚石表面部分覆盖有薄层c-BN外延岛。有限的氢反应是在掺硼金刚石上生长c-BN的有利环境。
Cubic boron nitride (c-BN), with a small 1.4% lattice mismatch with diamond, presents a heterostructure with multiple opportunities for electronic device applications. However, the formation of c-BN/diamond heterostructures has been limited by the tendency to form hexagonal BN at the interface. In this study, c-BN has been deposited on free standing polycrystalline and single crystal boron-doped diamond substrates via electron cyclotron resonance plasma enhanced chemical vapor deposition (ECR-PECVD), employing fluorine chemistry. In situ x-ray photoelectron spectroscopy (XPS) is used to characterize the nucleation and growth of boron nitride (BN) films as a function of hydrogen gas flow rates during deposition. The PECVD growth rate of BN was found to increase with increased hydrogen gas flow. In the absence of hydrogen gas flow, the BN layer was reduced in thickness or etched. The XPS results show that an excess of hydrogen gas significantly increases the percent of sp2 bonding, characteristic of hexagonal BN (h-BN), particularly during initial layer growth. Reducing the hydrogen flow, such that hydrogen gas is the limiting reactant, minimizes the sp2 bonding during the nucleation of BN. TEM results indicate the partial coverage of the diamond with thin epitaxial islands of c-BN. The limited hydrogen reaction is found to be a favorable growth environment for c-BN on boron-doped diamond.