Graphene field effect transistor terahertz wave modulator and manufacture method thereof

Abstract

The invention provides a graphene field effect transistor terahertz wave modulator and a manufacture method thereof and aims to increase the modulating speed and depth of the graphene field effect transistor terahertz wave modulator. The graphene field effect transistor terahertz wave modulator comprises a semiconductor substrate, and a medium layer, a graphene film and source and drain electrodes which are arranged on the substrate, and an annular grating electrode which is arranged on the back of the substrate. The terahertz wave modulator is characterized in that the medium layer is an Al2O3 layer, and the thickness ranges from 5 to 100nm; the Al2O3 is deposited by the ALD (atomic layer deposition) method, and the Al2O3 is high in evenness, is free of defects and pores and has better voltage resistance; the leakage current is reduced greatly. The modulating speed of the terahertz wave modulator can be 178 KHz, the corresponded modulating depth is larger than 22%, and the modulating speed and depth are increased significantly; the terahertz wave modulator can be widely applied to the fields of terahertz wave communication systems, terahertz wave detection and terahertz wave imaging.

Description

technical field [0001] The invention belongs to the technical field of terahertz wave application, and designs a terahertz wave modulator and a preparation method thereof, in particular to a graphene field effect transistor terahertz wave modulator and a preparation method thereof. Background technique [0002] Terahertz wave (THz) usually refers to electromagnetic radiation with a frequency in the range of 0.1THz-10THz (1THz=1012Hz), which is in the transition region between macroelectronics and microphotonics. Terahertz waves are the focus of next-generation communication technology. They are ideal tools for biomedical research and biochemical weapon detection. They also have very important applications in nondestructive testing, security inspections, and radar imaging. Graphene, as a two-dimensional monoatomic layer film material of carbon allotrope, has been discovered since 2004 with its unique structure, extraordinary electrical properties, optical properties, good mec...

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Problems solved by technology

[0003] In recent years, traditional graphene field effect transistor terahertz wave modulators use SiO with a thickness of 300nm or 98nm. 2 As a dielectric layer, but due to the thermal evaporation growth process is easy to cause SiO 2 Uneven surface, multiple defects, and multiple pinholes lead to large leakage current of the transistor and relatively low breakdown voltage, and the modulation rate and modulation depth of the terahertz wave modulator need to be improved

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