石墨烯晶体管转移特性对栅压的依赖现象研究

Graphene Transistor Transfer Properties Phenomenon Research Dependence on Gate Voltage

为了研究石墨烯场效应晶体管的不同测试方法,对其转移特性的影响,在栅压为0~5V之间扫描的情况下,研究了石墨烯晶体管的狄拉克点变化规律.其变化呈现以下特点:连续地正向扫描或反向扫描时,随着次数的增加,狄拉克点电压逐渐变大;先加栅压保持一段时间后,再测转移特性,0V保持时,狄拉克点电压不变,5V保持时,狄拉克点电压变大;测试之间相互独立时,正向扫描的狄拉克点电压小于反向扫描的狄拉克点电压;双向连续扫描时,第一次测试影响第二次的结果.以上现象表明了狄拉克点电压的大小和已扫描过的栅压大小有关.我们把上述的特点归因于电子注入到氧化铪表面的陷阱中.这些现象的发现和解释对石墨烯器件的可靠性,石墨烯导电特性的控制,石墨烯电路的实现有明显的参考意义.

To research the effect of transfer characteristic of graphene transistors by different test methods, change rules of Dirac points are researched, under the condition of that the scan range of gate voltage is between 0 V and 5 V. The changes present the following regularity. The Dirac point voltages increase gradually with the increase of scan times, when forward or backward sweeps are performed continuously. Before measurement, gate voltage hold is performed, then the Dirac point voltages have no changes when gate voltage sweeps with hold by 0V, but they increase with hold by 5V. When measurements are mutual independent, the Dirac point voltages with forward sweep are less than that with backward sweep. The first measurement can affect the second measurement when the double tests are performed. From the phenomenon above, Dirac point voltages are related to gate voltages that have swept. These properties are attributed to that electronics inject traps in surface of HfOe. These finding and analysis are significant in the graphene reliability, the control of graphene conduction characteristics, and the realization of graphene circuits.