A facile way to deposit conformal Al₂O₃ thin film on pristine graphene by atomic layer deposition

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• 作者：Yan-Qiang Cao ; Zheng-Yi Cao ; Xin Li ; Di Wu ; Ai-Dong Li
• 关键词：Graphene ; Atomic layer deposition ; Dielectrics ; Functionalization ; Water physisorption
• 刊名：Applied Surface Science
• 出版年：1 February, 2014
• 年：2014
• 卷：291
• 期：Complete
• 页码：78-82
• 全文大小：2159 K

文摘

It is important to prepare high-quality, ultrathin dielectric insulators on graphene for the integration of graphene field-effect transistors. Here, we present a novel and facile approach to deposit high-魏 dielectrics (such as Al₂O₃) by atomic layer deposition (ALD) through water physisorption. Usually it is difficult to grow Al₂O₃ thin films on pristine graphene directly using H₂O as precursor. The pretreatment of graphene with ALD H₂O pulses before the deposition can enhance the Al₂O₃ coverage on pristine graphene, but the film is not continuous yet. It is found that uniform Al₂O₃ thin films can easily deposit on the graphene after H₂O dipping pretreatment for 鈭?-5 h. It is ascribed to the fact that the physisorbed water molecules on the surface of graphene as nucleation sites react with the metal precursor of trimethylaluminum (TMA) to form Al₂O₃ dielectric films. Raman spectra reveal that no defects are produced on graphene surface via this method. These results indicate that water functionalization is a promising pathway to achieve scaled gate dielectrics on graphene without introducing any defects.