Reduction in Residual Impurities in Chemical Vapor Deposition-Grown Hexagonal Boron Nitride Thin Films
Reduction in Residual Impurities in Chemical Vapor Deposition-Grown Hexagonal Boron Nitride Thin Films
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减少化学气相沉积生长的六方氮化硼薄膜中的残留杂质
DOI：
10.1002/pssb.202200352
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发表时间：
2023
期刊：
影响因子：
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通讯作者：
Yamada Hisashi
中科院分区：
文献类型：
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作者：
荒井 修作;内田 諭;八木 一平;西川 宏之;関 宏範;Yamada Hisashi
研究了使用 B2H6 作为硼前体的 BN 模制基座通过 CVD 在 Al2O3 基板上化学气相沉积 (CVD) 生长的六方氮化硼 (h-BN) 中的残留杂质。获得的Si、C和O残留杂质分别为2.6 × 1016、3.4 × 1018和2.0 × 1017cm−3。这些浓度比使用三甲基硼 (TMB) 在 SiC 涂层石墨基座上生长时的浓度低两个数量级，并且是 CVD 生长的 h-BN 薄膜中的最低值。阴极发光光谱具有5.5 eV作为宽峰和4 eV作为多个峰。较高能量发射（5.79eV）下的自由激子复合是由于残余杂质的减少。仅当使用SiC涂层石墨基座时，才在低于5eV的能量范围内观察到1 × 104cm−1的吸收系数，这很可能与BN层中的Si污染有关。使用 BN 模制基座时，吸收系数可以忽略不计，呈现出高纯度 h-BN 特征。
The residual impurities in chemical vapor deposition (CVD)‐grown hexagonal boron nitride (h‐BN) on Al2O3substrate grown by CVD using BN‐molded susceptor with B2H6as a boron precursor are investigated. The Si, C, and O residual impurities of 2.6 × 1016, 3.4 × 1018, and 2.0 × 1017cm−3are achieved. These concentrations are two orders of magnitude lower than those when grown on the SiC‐coated graphite susceptor using trimethylboron (TMB) and the lowest values in the CVD‐grown h‐BN thin films. The cathodoluminescence spectrum has 5.5 eV as a broad peak and 4 eV as several peaks. The free excitonic recombination at the higher energy emission (5.79 eV) is owing to the reduction in residual impurities. The absorption coefficient of 1 × 104cm−1is observed in the energy range below 5 eV only when using the SiC‐coated graphite susceptor, which is most probably associated with Si contamination in the BN layer. The negligible absorption coefficient when using the BN‐molded susceptor presents high‐purity h‐BN signature.