The Miniaturized Terahertz Source Based On Two Dimensional Electron Gas From GaN Semiconductor Heterostructure

With the development of semiconductor technology and the research and expectation of terahertz system,people try to use semiconductor as a terahertz source,for which research has been done for many years.Semiconductor terahertz technology is conducive to the realization of miniaturized terahertz radiation sources,so it is favored.Among them,AlGaN/GaN heterostructure has become a research hotspot for its huge advantages.Most of the design principles of terahertz sources studied in the past are based on surface plasma waves.The semiconductor GaN heterojunction terahertz source studied in this paper is also based on two-dimensional electron gas surface plasma wave.This paper starts with the discussion of two-dimensional electron gas plasma excitation,studies the unstable amplification of plasma wave and resonance of plasma wave,and completes the simulation of plasma wave in GaN heterojunction and the experimental verification of radiation power.The main research contents of thesis are as follows:The advantages and methods of studying two-dimensional electron gas excited surface plasma waves are given,and the simulation verification of CST is carried out,which proves that two-dimensional electron gas under grating coupling can stimulate plasma waves in terahertz band.The influence of structural parameters of radiation source devices based on AlGaN/GaN materials on radiation is explored,including: 1.The length of twodimensional electron gas,2.Gate voltage,3.Tthe voltage between source and drain,4.Gate position.Finally,the radiation under different structural parameters is optimized by simulation,and it is verified that the device can radiate more than 1THz electromagnetic wave.According to the parameters of the simulation structure,the physical device was processed and prepared,and the output,transfer and power characteristics of the device were carried out.Combined with the above experimental results,the working characteristics of the device were analyzed,including the influence of the source drain voltage and gate voltage on the output current and power of the device,and the corresponding relationship between the change trend of the output power and output current was obtained.At saturation power and saturation current the source-drain voltage and g voltage correspond to the same.The experimental verification of 1-3THz semiconductor radiation source is completed.The frequency band is consistent with the simulation results.In thesis,from the theoretical analysis method to the simulation verification,and then to the final physical device processing,we successfully verified that the 1-3THz terahertz radiation source based on GaN semiconductor heterojunction can be miniaturized by using the two-dimensional electron gas in it.Thus,it can be shown that semiconductor heterostructure has a good advantage for the study of miniaturized terahertz sources.