Department of Engineering, University of Cambridge, 9 JJ Thomson Avenue, Cambridge CB3 0FA, United Kingdom.
Nanotechnology. 2017 Dec 1;28(48):485201. doi: 10.1088/1361-6528/aa940c.
The transfer of chemical vapour deposited graphene from its parent growth catalyst has become a bottleneck for many of its emerging applications. The sacrificial polymer layers that are typically deposited onto graphene for mechanical support during transfer are challenging to remove completely and hence leave graphene and subsequent device interfaces contaminated. Here, we report on the use of atomic layer deposited (ALD) oxide films as protective interface and support layers during graphene transfer. The method avoids any direct contact of the graphene with polymers and through the use of thicker ALD layers (≥100 nm), polymers can be eliminated from the transfer-process altogether. The ALD film can be kept as a functional device layer, facilitating integrated device manufacturing. We demonstrate back-gated field effect devices based on single-layer graphene transferred with a protective AlO film onto SiO that show significantly reduced charge trap and residual carrier densities. We critically discuss the advantages and challenges of processing graphene/ALD bilayer structures.
化学气相沉积石墨烯从其母体生长催化剂上的转移已经成为其许多新兴应用的瓶颈。通常为了在转移过程中对石墨烯进行机械支撑而沉积在石墨烯上的牺牲聚合物层很难完全去除，因此会使石墨烯和后续器件界面受到污染。在这里，我们报告了在石墨烯转移过程中使用原子层沉积（ALD）氧化物薄膜作为保护界面和支撑层。该方法避免了石墨烯与聚合物的任何直接接触，并且通过使用更厚的 ALD 层（≥100nm），可以完全消除转移过程中的聚合物。ALD 薄膜可以作为功能器件层保留下来，从而方便集成器件的制造。我们展示了基于单层石墨烯的背栅场效应器件，该器件使用保护性 AlO 薄膜转移到 SiO 上，显示出明显降低的电荷俘获和残余载流子密度。我们批判性地讨论了处理石墨烯/ALD 双层结构的优点和挑战。
