The interface condition between the graphene channel and aluminum oxide (Al₂O₃) gate insulator in a graphene field-effect transistor (FET) has been analyzed. The hard X-ray photoelectron spectroscopy technique was employed to analyze the interface. In the obtained C1s spectra, a small peak was found at 284.2eV, which was considered to be derived from a covalent bond between the graphene and Al₂O₃. In the pulsed S-parameters measurements, it was found that the direction of the Dirac voltage shift matched the polarity of the applied voltage stress. The Dirac voltage shift demonstrated that there were electron traps at the interface, degrading the FET performance such as the cutoff frequency. It was concluded that the unexpected bond at the interface formed electron traps whose energy level located near the conduction band minimum and that the Dirac voltage shifted in accordance with carrier capturing or emitting by the traps.

分析了石墨烯场效应晶体管（FET）中石墨烯沟道与氧化铝（Al ₂ O ₃）栅极绝缘体之间的界面条件。用硬X射线光电子能谱技术分析界面。在获得的C1s光谱中，在284.2eV处发现一个小峰，该峰被认为源自石墨烯和Al ₂ O ₃之间的共价键。。在脉冲S参数测量中，发现狄拉克电压偏移的方向与施加的电压应力的极性匹配。狄拉克电压偏移表明界面处存在电子陷阱，从而降低了FET性能，例如截止频率。结论是，在界面处的意外键形成了电子陷阱，其能级位于导带附近最小，并且狄拉克电压根据陷阱捕获或发射的载流子而移动。