Electron-enhanced atomic layer deposition (EE-ALD) was used to deposit boron nitride (BN) thin films at room temperature and 100 °C using sequential exposures of borazine (B₃N₃H₆) and electrons. Electron-stimulated desorption (ESD) of hydrogen surface species and the corresponding creation of reactive dangling bonds are believed to facilitate borazine adsorption and reduce the temperature required for BN film deposition. In situ ellipsometry measurements showed that the BN film thickness increased linearly versus the number of EE-ALD cycles at room temperature. Maximum growth rates of ∼3.2 Å/cycle were measured at electron energies of 80–160 eV. BN film growth was self-limiting versus borazine and electron exposures, as expected for an ALD process. The calculated average hydrogen ESD cross section was σ = 4.2 × 10^–17 cm². Ex situ spectroscopic ellipsometry measurements across the ∼1 cm² area of the BN film defined by the electron beam displayed good uniformity in thickness. Ex situ X-ray photoelectron spectroscopy and in situ Auger spectroscopy revealed high purity, slightly boron-rich BN films with C and O impurity levels <3 at. %. High-resolution transmission electron microscopy (HR-TEM) imaging revealed polycrystalline hexagonal and turbostratic BN with the basal planes approximately parallel to the substrate surface. Ex situ grazing incidence X-ray diffraction measurements observed peaks consistent with hexagonal BN with domain sizes of 1–2 nm. The BN EE-ALD growth rate of ∼3.2 Å/cycle is close to the distance of 3.3 Å between BN planes in hexagonal BN. The growth rate and HR-TEM images suggest that approximately one monolayer of BN is deposited for every BN EE-ALD cycle. TEM and scanning TEM/electron energy loss spectroscopy measurements of BN EE-ALD on trenched wafers also showed preferential BN EE-ALD on the horizontal surfaces. This selective deposition on the horizontal surfaces suggests that EE-ALD may enable bottom-up filling of vias and trenches.

中文翻译：

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室温和100°C下氮化硼薄膜的电子增强原子层沉积

使用硼原子（B ₃ N ₃ H _6）连续曝光，在室温和100°C下使用电子增强原子层沉积（EE-ALD）沉积氮化硼（BN）薄膜）和电子。认为氢表面物质的电子刺激解吸（ESD）和相应的反应性悬挂键的形成有助于硼嗪的吸附并降低BN膜沉积所需的温度。原位椭圆光度法测量表明，在室温下，BN膜厚度相对于EE-ALD循环数线性增加。在80-160 eV的电子能量下测得的最大生长速率约为3.2Å/循环。BN膜的生长是自限性的，而硼烷和电子的暴露是自限性的，这是ALD工艺所期望的。计算得出的平均ESD氢截面为σ= 4.2×10 – ¹⁷ cm ²。在约1 cm ²上进行异位椭圆偏振光谱测量由电子束限定的BN膜的面积在厚度上显示出良好的均匀性。异位X射线光电子能谱和原位俄歇能谱仪显示出高纯度，含硼量稍高的BN膜，其C和O杂质含量<3 at。％。高分辨率透射电子显微镜（HR-TEM）成像显示多晶六方和涡轮层BN，其基面近似平行于基材表面。异地掠入射X射线衍射测量观察到峰与六角形BN一致，畴尺寸为1-2 nm。BN EE-ALD每周期的生长速率约为3.2Å，接近六边形BN中BN平面之间的3.3Å距离。增长率和HR-TEM图像表明，对于每个BN EE-ALD循环，大约沉积了一层BN。在沟槽晶片上的BN EE-ALD的TEM和扫描TEM /电子能量损失谱测量也显示在水平表面上具有优先的BN EE-ALD。在水平表面上的这种选择性沉积表明EE-ALD可以自底向上填充通孔和沟槽。