论文标题
顺序浸润合成过程中PMMA薄膜中的三甲基铝扩散：原位动态光谱椭圆测量
Trimethylaluminum Diffusion in PMMA Thin Films during Sequential Infiltration Synthesis: In Situ Dynamic Spectroscopic Ellipsometric Investigation
论文作者
论文摘要
顺序浸润合成（SIS）通过将气态前体穿透到聚合物中，为聚合物提供了一条成功的途径，以增强聚合物的功能性能，从而形成有机无机杂交材料的功能性能，并在构造无线电疗法时制造无机层构造或构成式隔音仪的构造或构成式构造的膜片。 SIS过程由原子层沉积（ALD）反应器中聚合物膜的金属有机前体和共反应蒸气循环组成。在这项工作中，我们使用三甲基铝（TMA）和H2O在各种聚合物膜中使用原位动态光谱椭圆法（SE）介绍了氧化铝过程的研究。原位动态SE可以对聚合物的肿胀进行时间分辨的监测，这与金属前体的扩散和保留有关聚合物本身。当暴露于TMA蒸气时，观察到聚（甲基丙烯酸酯）（PMMA）和聚苯乙烯（PS）的不同肿胀行为。 PMMA膜比PS膜更明显地膨胀，从而导致O2血浆中聚合物去除后浸润的Al2O3厚度非常不同。 TMA暴露和与H2O反应时，PMMA膜达到了不同的肿胀状态，具体取决于TMA剂量和TMA暴露后的清除持续时间，这对应于保留在聚合物内部并转化为氧化铝的不同量的金属前体。提取TMA中TMA的扩散系数研究了TMA浸润过程中原始PMMA膜的肿胀，并显示出依赖于聚合物分子量的肿胀。原位动态SE监测允许控制SIS过程，从类似ALD的过程进行调整，以进行长时间清除到化学蒸气沉积 - 例如，在聚合物膜中选择性地限制了过程
Sequential infiltration synthesis (SIS) provides a successful route to grow inorganic materials into polymeric films by penetrating of gaseous precursors into the polymer, both in order to enhance the functional properties of the polymer creating an organic-inorganic hybrid material, and to fabricate inorganic nanostructures when infiltrating in patterned polymer films or in selfassembled block copolymers. A SIS process consists in a controlled sequence of metal organic precursor and co-reactant vapor exposure cycles of the polymer films in an atomic layer deposition (ALD) reactor. In this work, we present a study of the SIS process of alumina using trimethylaluminum (TMA) and H2O in various polymer films using in situ dynamic spectroscopic ellipsometry (SE). In situ dynamic SE enables time-resolved monitoring of the swelling of the polymer, which is relevant to the diffusion and retain of the metal precursor into the polymer itself. Different swelling behaviour of poly(methylmethacrylate) (PMMA) and polystyrene (PS) was observed when exposed to TMA vapor. PMMA films swell more significantly than PS films do, resulting in very different infiltrated Al2O3 thickness after polymer removal in O2 plasma. PMMA films reach different swollen states upon TMA exposure and reaction with H2O, depending on the TMA dose and on the purge duration after TMA exposure, which correspond to different amounts of metal precursor retained inside the polymer and converted to alumina. Diffusion coefficients of TMA in PMMA were extracted investigating the swelling of pristine PMMA films during TMA infiltration and shown to be dependent on polymer molecular weight. In situ dynamic SE monitoring allows to control the SIS process tuning it from an ALD-like process for long purge to a chemical vapour deposition - like process selectively confined inside the polymer films
