Atomic Layer Deposition of Dielectrics on Graphene Using Reversibly Physisorbed Ozone

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• 作者：Srikar Jandhyala ; Greg Mordi ; Bongki Lee ; Geunsik Lee ; Carlo Floresca ; Pil-Ryung Cha ; Jinho Ahn ; Robert M. Wallace ; Yves J. Chabal ; Moon J. Kim ; Luigi Colombo ; Kyeongjae Cho ; Jiyoung Kim
• 刊名：ACS Nano
• 出版年：2012
• 出版时间：March 27, 2012
• 年：2012
• 卷：6
• 期：3
• 页码：2722-2730
• 全文大小：480K
• 年卷期：v.6,no.3(March 27, 2012)
• ISSN：1936-086X

文摘

Integration of graphene field-effect transistors (GFETs) requires the ability to grow or deposit high-quality, ultrathin dielectric insulators on graphene to modulate the channel potential. Here, we study a novel and facile approach based on atomic layer deposition through ozone functionalization to deposit high-魏 dielectrics (such as Al₂O₃) without breaking vacuum. The underlying mechanisms of functionalization have been studied theoretically using ab initio calculations and experimentally using in situ monitoring of transport properties. It is found that ozone molecules are physisorbed on the surface of graphene, which act as nucleation sites for dielectric deposition. The physisorbed ozone molecules eventually react with the metal precursor, trimethylaluminum to form Al₂O₃. Additionally, we successfully demonstrate the performance of dual-gated GFETs with Al₂O₃ of sub-5 nm physical thickness as a gate dielectric. Back-gated GFETs with mobilities of 19鈥?00 cm²/(V路s) are also achieved after Al₂O₃ deposition. These results indicate that ozone functionalization is a promising pathway to achieve scaled gate dielectrics on graphene without leaving a residual nucleation layer.

Keywords:

graphene; dielectrics; atomic layer deposition; noncovalent functionalization; physisorption; nanoelectronics