Low-temperature Al2O3 atomic layer deposition
Low-temperature Al2O3 atomic layer deposition
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DOI：
10.1021/cm0304546
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发表时间：
2004-02-24
影响因子：
8.6
通讯作者：
George, SM
中科院分区：
文献类型：
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作者：
Groner, MD;Fabreguette, FH;George, SM
在粘性流反应器中，通过原子层沉积（ALD）技术，使用三甲基铝（TMA）[Al(CH₃)₃]和H₂O交替暴露，在低至33℃的温度下沉积了Al₂O₃薄膜。低温Al₂O₃原子层沉积薄膜有可能涂覆热敏感的基底，如有机、聚合物或生物材料。通过在Si(100)基底和石英晶体微天平（QCM）传感器上沉积薄膜，研究了低温Al₂O₃原子层沉积薄膜的性能随生长温度的变化。使用表面轮廓仪、原子力显微镜（AFM）、QCM和光谱椭圆偏振仪测定了Al₂O₃薄膜的厚度、生长速率、密度和光学性质。在较低的沉积温度下，Al₂O₃薄膜的密度较低。在177℃时，Al₂O₃原子层沉积薄膜的密度为3.0 g/cm³，在33℃时为2.5 g/cm³。原子力显微镜图像显示，在低温下生长的Al₂O₃原子层沉积薄膜非常光滑，均方根（RMS）粗糙度仅为4±1 Å。电流 - 电压和电容 - 电压测量表明低温Al₂O₃原子层沉积薄膜具有良好的电学性能。使用前向反冲光谱法对薄膜进行元素分析，结果显示氢浓度随生长温度的降低而增加。除了母体铝和氧的浓度外，卢瑟福背散射光谱法未观察到其他元素。首次在聚对苯二甲酸乙二醇酯（PET）聚合物基底上展示了在58℃的低温Al₂O₃原子层沉积。在PET瓶上的Al₂O₃原子层沉积涂层导致CO₂气体渗透率降低。
Al2O3 films were deposited by atomic layer deposition (ALD) at temperatures as low as 33 degreesC in a viscous-flow reactor using alternating exposures of Al(CH3)(3) (trimethylaluminum [TMA]) and H2O. Low-temperature Al2O3 ALD films have the potential to coat thermally fragile substrates such as organic, polymeric, or biological materials. The properties of low-temperature Al2O3 ALD films were investigated versus growth temperature by depositing films on Si(100) substrates and quartz crystal microbalance (QCM) sensors. Al2O3 film thicknesses, growth rates, densities, and optical properties were determined using surface profilometry, atomic force microscopy (AFM), QCM, and spectroscopic ellipsometry. Al2O3 film densities were lower at lower deposition temperatures. Al2O3 ALD film densities were 3.0 g/cm(3) at 177 degreesC and 2.5 g/cm(3) at 33 degreesC. AFM images showed that Al2O3 ALD films grown at low temperatures were very smooth with a root-mean-squared (RMS) roughness of only 4 +/- 1 A. Current-voltage and capacitance-voltage measurements showed good electrical properties of the low-temperature Al2O3 ALD films. Elemental analysis of the films using forward recoil spectrometry revealed hydrogen concentrations that increased with decreasing growth temperature. No other elements were observed by Rutherford backscattering spectrometry except the parent aluminum and oxygen concentrations. Low-temperature Al2O3 ALD at 58 degreesC was demonstrated for the first time on a poly(ethylene terephthalate) (PET) polymeric substrate. Al2O3 ALD coatings on PET bottles resulted in reduced CO2 gas permeabilities.