Parameter Space of Atomic Layer Deposition of Ultrathin Oxides on Graphene.
Parameter Space of Atomic Layer Deposition of Ultrathin Oxides on Graphene.
复制标题
超薄氧化物在石墨烯上的原子层沉积的参数空间。
DOI：
10.1021/acsami.6b09596
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发表时间：
2016-11-09
影响因子：
9.5
通讯作者：
Hofmann S
中科院分区：
文献类型：
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作者：
Aria AI;Nakanishi K;Xiao L;Braeuninger-Weimer P;Sagade AA;Alexander-Webber JA;Hofmann S
系统研究了在支撑化学气相沉积（CVD）石墨烯上原子层沉积（ALD）法制备氧化铝（AlOx）薄膜。我们表明，通过延长前体停留时间，使用多脉冲序列或浸泡期，即使在200 °C的高沉积温度下，也可以使用标准H2O和三甲基铝（TMA）前体在石墨烯上直接实现连续AlOx膜，而无需使用表面活性剂或其他额外的石墨烯表面改性。为了获得共形成核，需要>2s的前体停留时间，这不是过分长的，但足以说明石墨烯表面的缓慢吸附动力学。相比之下，较短的停留时间导致非均质成核，其优先于石墨烯上的缺陷/选择性位点。这些发现表明，仔细控制ALD参数空间对于控制CVD石墨烯上AlOx的成核行为至关重要。我们认为我们的研究结果具有合理的二维（2D）/非2D材料工艺集成的模型系统特性，也与许多其他新兴的2D材料的接口和器件集成有关。
Atomic layer deposition (ALD) of ultrathin aluminum oxide (AlOx) films was systematically studied on supported chemical vapor deposition (CVD) graphene. We show that by extending the precursor residence time, using either a multiple-pulse sequence or a soaking period, ultrathin continuous AlOx films can be achieved directly on graphene using standard H2O and trimethylaluminum (TMA) precursors even at a high deposition temperature of 200 °C, without the use of surfactants or other additional graphene surface modifications. To obtain conformal nucleation, a precursor residence time of >2s is needed, which is not prohibitively long but sufficient to account for the slow adsorption kinetics of the graphene surface. In contrast, a shorter residence time results in heterogeneous nucleation that is preferential to defect/selective sites on the graphene. These findings demonstrate that careful control of the ALD parameter space is imperative in governing the nucleation behavior of AlOx on CVD graphene. We consider our results to have model system character for rational two-dimensional (2D)/non-2D material process integration, relevant also to the interfacing and device integration of the many other emerging 2D materials.