Conformal and Stoichiometric Chemical Vapor Deposition of Silicon Carbide onto Ultradeep Heterogeneous Micropores by Controlling the Initial Nucleation Stage.
Conformal and Stoichiometric Chemical Vapor Deposition of Silicon Carbide onto Ultradeep Heterogeneous Micropores by Controlling the Initial Nucleation Stage.
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通过控制初始成核阶段将碳化硅保形化学计量化学气相沉积到超深异质微孔上。
DOI：
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发表时间：
2021
影响因子：
9.5
通讯作者：
Y. Shimogaki
中科院分区：
文献类型：
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作者：
K. Shima;Y. Otaka;N. Sato;Yuichi Funato;Y. Fukushima;T. Momose;Y. Shimogaki
使用甲基三氯硅烷 (MTS) 和氢气 (H2) 对碳化硅 (SiC) 进行共形化学气相沉积 (CVD) 到高纵横比 (HAR；通常 >100:1) 三维特征上一直是陶瓷基复合材料制造中的挑战。在本研究中，使用 HAR (1000:1) 微通道和定制的 Si(100) 润湿底层以及热形成的非晶二氧化硅 (a-SiO2) 和乱层氮化硼 (t-BN) 去湿底层，研究了异质底层对 SiC-CVD 初始成核的影响。孵化期分布在 a-SiO2 和 t-BN 底层的微通道中，由于成膜物质的浓度 (C) 降低，在特征底部发现最长的孵化期为 70 分钟。由于初始成核作用降低，导致较长的潜伏期和更多去湿底层的出现。特征底部的长时间孵育导致保形性差，因为当特征底部开始成膜时，入口处已经形成厚膜。根据经典异相成核理论，通过增加 MTS/H2 的供应来消除潜伏期。与此同时，在特征底部的去湿 a-SiO2 和 t-BN 底层附近形成了富碳 SiC 薄膜，在去湿底层上具有更大的碳偏析。这可能是由于 MTS/H2 在气相中产生的热解碳（CH4、C2H2 和/或 C2H4）的沉积所致。将温度 (T) 从 1000 °C 降低至 900 °C 可防止富碳薄膜的形成，对于 CH4，热解碳的预期沉积率降至 0.6%。 MTS/H2 的较高 C 值与较低 T 值相结合，能够在异质 HAR 特征上形成保形和化学计量薄膜。
Conformal chemical vapor deposition (CVD) of silicon carbide (SiC) from methyltrichlorosilane (MTS) and hydrogen (H2) onto high-aspect-ratio (HAR; typically >100:1) three-dimensional features has been a challenge in the fabrication of ceramic matrix composites. In this study, the impact of heterogeneous underlayers on the initial nucleation of SiC-CVD was studied using HAR (1000:1) microchannels with a tailored wetting underlayer of Si(100) and dewetting underlayers of thermally formed amorphous silicon dioxide (a-SiO2) and turbostratic boron nitride (t-BN). Incubation periods were distributed in the microchannels on a-SiO2 and t-BN underlayers, with the longest period of 70 min found at the feature-bottom due to a decreased concentration (C) of film-forming species. The longer incubation periods with more dewetting underlayers arose due to demoted initial nucleation. Prolonged incubation at the feature bottom led to poor conformality because thick films had already formed at the inlet when film formation began at the feature bottom. The incubation periods were eliminated by increasing the supply of MTS/H2, in accordance with classical heterogeneous nucleation theory. In the meantime, carbon-rich SiC films formed in the vicinity of dewetting a-SiO2 and t-BN underlayers at the feature bottoms, with greater carbon segregation on more dewetting underlayers. This was probably due to the deposition of pyrocarbons (CH4, C2H2, and/or C2H4) generated from MTS/H2 in the gas phase. Decreasing the temperature (T) from 1000 to 900 °C prevented carbon-rich film formation, and the expected deposition rate of pyrocarbon decreased to 0.6% for the case of CH4. A higher C of MTS/H2 combined with a lower T enabled conformal and stoichiometric film formation on the heterogeneous HAR features.
通过化学气相沉积无缝填充深沟槽：使用分子生长抑制剂消除夹断
影响因子：
2.9
作者：
Talukdar, Tushar K.;Girolami, Gregory S.;Abelson, John R.
通讯作者：
Abelson, John R.