摘要

Scanning tunnelling microscope (STM) electric lithography exhibits its unique advantages in the nanoscale positioning accuracy, in situ measurement, atomic manipulation and ultra-precise fabrication. Nowadays various nanoscale structures and devices have been delivered from STM electric lithography by versatile means of the local mechanical force, the chemical reaction and the thermal effects. In this paper, the authors have innovatively utilised the nanoscale electric discharge effect induced by the STM electric lithography to peel off the site-specific few layer graphene (FLG) flakes on the highly oriented pyrolytic graphite sample. The piece number, distribution, area and thickness of the exfoliated graphene flakes generated under the different machining parameter settings were quantitatively analysed. It has been found out that both of the machining gap distance and the bias voltage amplitude play the decisive roles in the exfoliation of the FLG flakes. Moreover, the machining current was measured to validate the occurrence of the nanoscale electric discharge during the STM electric lithography processes. It directly proves the relevance of FLG flakes peeling off to the electric discharge. This work has confirmed the processing capability of the STM electric lithography for the FLG flakes peeling off, which is desired in the fabrication of graphene-based nanodevices.

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