Preparation method for side gating graphene field effect transistor

Abstract

The invention discloses a preparation method for a side gating graphene field effect transistor structure based on chemical vapor deposition graphene. The preparation method comprises placing copper foil in a reaction chamber, vacuumizing the reaction chamber, and performing thermal annealing on the copper foil; growing the graphene by chemical vapor deposition (CVD); transferring the graphene to a high k substrate; utilizing a lithography machine to expose source drain and side gating positions; utilizing an oxygen plasma etching machine to etch the graphene at the side gating positions; using an E-beam device to evaporate metal on a sample; enabling the sample where the metal is evaporated to be placed in acetone to perform ultrasonography, then rinsing the sample in absolute ethyl alcohol, using deionized water to flush the sample, and finally using pure nitrogen to dry the sample. Due to the fact that the side gating structure is adopted, deposition of a top gate medium is avoided, and poor influence of the top gate medium on the graphene material property is avoided. Due to the fact that the high k substrate is adopted, the modulation capability of side gating on a graphene conducting channel is improved.

Description

technical field [0001] The invention belongs to the field of integrated circuit manufacturing and relates to the design and processing of semiconductor devices, in particular to a method for preparing a side-gate graphene field-effect transistor structure based on chemical vapor deposition graphene, which can be used to improve the production efficiency and electrical properties of graphene devices. performance. Background technique [0002] Graphene is an emerging two-dimensional material, and its conductivity type is bipolar transport, which provides the possibility to manufacture new graphene devices. The potential of using graphene to fabricate high-frequency field-effect transistors has attracted extensive research interest. In addition, graphene is also considered to be an ideal material for a new generation of high-frequency electronic devices due to its high mobility, high carrier saturation velocity, and high thermal conductivity. [0003] At present, the gate of ...

AI Technical Summary

Problems solved by technology

[0005] At present, the side gate graphene field effect transistor made of pyrolytic SiC has proved that the side gate structure does have the ability to control the transport properties of the graphene conductive channel, but the capacitance per unit area of ​​the side gate is only 0.12 μF / cm2-0.16 μF / cm 2 , which is lower than that of top-gate field-effect transistors made of graphene (0.74 μF / cm 2 ), such a small capacitance per unit area of ​​the side gate is not conducive to further improving the transconductance of the field effect transistor

More importantly, to achieve the maximum transconductance of the side-gate structure, an external driving voltage of 5 V-8 V needs to be applied to the source-drain electrodes. Too high voltage and current can easily damage the graphene as a conductive channel.

Moreover, although the side gate structure has been applied to graphene prepared by mechanical exfoliation and graphene prepared by SiC pyrolysis, it is difficult to obtain large-area graphene materials by mechanical exfoliation, while graphene prepared by SiC pyrolysis requires High pyrolysis temperature and expensive SiC wafers

Images