The graphene field-effect transistor (GFET) with a thin insulating oxide layer can regulate electrical performance under small voltage. After reactive ion etching of 300 nm SiO₂, the substrates with different shapes and thicknesses are used to fabricate GFET. The electrical performance test proves that GFETs with suspended structures have high carrier mobility. Compared with the suspended structures that should uphold voltage within 15 V, a device with SiO₂ thickness of 10 nm can achieve superior electrical regulation only within 4 V. The thin insulating oxide layer increases the risk of breakdown. Under the high electric field, the thin oxide layer will be broken down to form a conductive channel, and the interface between graphene and substrate will generate metal-semiconductor contact, forming Schottky-like diode. The electrical properties have changed at this stage. There is an electric current flowing through internal conduction, and the transfer characteristics change from bipolar to unipolar. This research provides a new idea to realize small voltage regulation and a basis for judging graphene transistor failure.

具有薄绝缘氧化物层的石墨烯场效应晶体管（GFET）可以在小电压下调节电性能。在300 nm SiO _2的反应离子刻蚀之后，具有不同形状和厚度的基板被用于制造GFET。电气性能测试证明，具有悬浮结构的GFET具有高载流子迁移率。与应该在15 V之内保持电压的悬挂结构相比，采用SiO ₂的器件10 nm的厚度仅在4 V内即可实现出色的电调节。薄的绝缘氧化物层会增加击穿的风险。在高电场下，薄的氧化层将被分解形成导电通道，石墨烯与基板之间的界面将产生金属-半导体接触，从而形成肖特基二极管。在此阶段，电性能已经改变。电流流过内部传导，并且传输特性从双极性变为单极性。该研究为实现小电压调节提供了新思路，为判断石墨烯晶体管的故障提供了依据。